{"id":65,"date":"2019-06-29T16:17:38","date_gmt":"2019-06-29T14:17:38","guid":{"rendered":"http:\/\/localhost\/?page_id=65"},"modified":"2026-01-15T10:11:30","modified_gmt":"2026-01-15T09:11:30","slug":"designrules","status":"publish","type":"page","link":"https:\/\/page.be\/electronica\/designrules\/","title":{"rendered":"Designrules"},"content":{"rendered":"<div id=\"pl-65\"  class=\"panel-layout\" ><div id=\"pg-65-0\"  class=\"panel-grid panel-has-style\" ><div data-overlay-opactity=\"1\" class=\"panel-row-style panel-row-style-for-65-0\" ><div id=\"pgc-65-0-0\"  class=\"panel-grid-cell\" ><div id=\"panel-65-0-0-0\" class=\"so-panel widget widget_themegrill_flash_heading tg-widget section-title-wrapper panel-first-child panel-last-child\" data-index=\"0\" >\t<div class=\"heading heading-center divider-without-icon no-divider\">\n\t<h3 class=\"section-title\">Design for manufacturing<\/h3>\n<\/div>\n<\/div><\/div><\/div><\/div><div id=\"pg-65-1\"  class=\"panel-grid panel-has-style\" ><div class=\"siteorigin-panels-stretch panel-row-style panel-row-style-for-65-1\" data-stretch-type=\"full\" data-overlay-opactity=\"1\" ><div id=\"pgc-65-1-0\"  class=\"panel-grid-cell\" ><div id=\"panel-65-1-0-0\" class=\"so-panel widget widget_sow-image panel-first-child\" data-index=\"1\" ><div class=\"wow fadeInUp panel-widget-style panel-widget-style-for-65-1-0-0\" data-wow-offset=\"10\" data-wow-iteration=\"1\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-image so-widget-sow-image-default-c67d20f9f743-65\"\n\t\t\t\n\t\t>\n<div class=\"sow-image-container\">\n\t\t\t<a href=\"https:\/\/page.be\/file_static\/e\/r\/dfx_manual_2024_en_pagebe.pdf\"\n\t\t\ttarget=\"_blank\" rel=\"noopener noreferrer\" \t\t>\n\t\t\t<img \n\tsrc=\"https:\/\/page.be\/electronica\/wp-content\/uploads\/sites\/3\/2025\/10\/dfx_manual_2024_en_pagebe-209x300.png\" width=\"209\" height=\"300\" srcset=\"https:\/\/page.be\/electronica\/wp-content\/uploads\/sites\/3\/2025\/10\/dfx_manual_2024_en_pagebe-209x300.png 209w, https:\/\/page.be\/electronica\/wp-content\/uploads\/sites\/3\/2025\/10\/dfx_manual_2024_en_pagebe.png 292w\" sizes=\"(max-width: 209px) 100vw, 209px\" alt=\"\" \t\tclass=\"so-widget-image\"\/>\n\t\t\t<\/a><\/div>\n\n<h3 class=\"widget-title\"><\/h3><\/div><\/div><\/div><div id=\"panel-65-1-0-1\" class=\"so-panel widget widget_sow-editor panel-last-child\" data-index=\"2\" ><div class=\"wow fadeInUp panel-widget-style panel-widget-style-for-65-1-0-1\" data-wow-offset=\"10\" data-wow-iteration=\"1\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-editor so-widget-sow-editor-base\"\n\t\t\t\n\t\t>\n<div class=\"siteorigin-widget-tinymce textwidget\">\n\t<p style=\"text-align: center;\"><em>Auteur: <a href=\"mailto:bart.lozie@page.be\">Bart Lozie<\/a><br \/>\n<\/em><em>Laatste update: 9\/01\/2026<\/em><\/p>\n<\/div>\n<\/div><\/div><\/div><\/div><div id=\"pgc-65-1-1\"  class=\"panel-grid-cell\" ><div id=\"panel-65-1-1-0\" class=\"so-panel widget widget_sow-editor panel-first-child\" data-index=\"3\" ><div class=\"panel-widget-style panel-widget-style-for-65-1-1-0\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-editor so-widget-sow-editor-base\"\n\t\t\t\n\t\t>\n<div class=\"siteorigin-widget-tinymce textwidget\">\n\t<h4>DFM: Tips &amp; Tricks manual<\/h4>\n<p>Deze bundel werd geschreven voor de klanten van Page Electronica NV en beschrijven vaak voorkomende designtechnische problemen. Bewust werd er niet te diep in detail getreden.<\/p>\n<p>Bij vragen kunt u het best de <a href=\"mailto:bart.lozie@page.be\" target=\"_blank\" rel=\"noopener\">process engineer<\/a> raadplegen, zie ook <a href=\"https:\/\/page.be\/electronica\/contact\/\" target=\"_blank\" rel=\"noopener\">contact<\/a>.<\/p>\n<\/div>\n<\/div><\/div><\/div><div id=\"panel-65-1-1-1\" class=\"so-panel widget widget_themegrill_flash_button tg-widget tg-button-widget panel-last-child\" data-index=\"4\" ><div class=\"wow fadeInUp panel-widget-style panel-widget-style-for-65-1-1-1\" data-wow-offset=\"10\" data-wow-iteration=\"1\" >\n<div class=\"tg-btn__container tg-btn__container--btn-left\">\n\t\t<a target=&quot;_blank&quot; class=\"tg-button tg-button--round tg-button--large\" href=\"https:\/\/page.be\/file_static\/e\/r\/dfx_manual_2024_en_pagebe.pdf\">\n\t\t\t<span class=\"tg-button__icon fa fa-download tg-button__icon--right\"><\/span>\n\t\t<span class=\"tg-button__label\">Download<\/span>\n\t<\/a>\n<\/div>\n<\/div><\/div><\/div><\/div><\/div><div id=\"pg-65-2\"  class=\"panel-grid panel-has-style\" ><div data-overlay-opactity=\"1\" class=\"panel-row-style panel-row-style-for-65-2\" ><div id=\"pgc-65-2-0\"  class=\"panel-grid-cell\" ><div id=\"panel-65-2-0-0\" class=\"so-panel widget widget_themegrill_flash_heading tg-widget section-title-wrapper panel-first-child panel-last-child\" data-index=\"5\" >\t<div class=\"heading heading-center divider-without-icon no-divider\">\n\t<h3 class=\"section-title\">Een korte samenvatting van de belangrijkste zaken<\/h3>\n<\/div>\n<\/div><\/div><\/div><\/div><div id=\"pg-65-3\"  class=\"panel-grid panel-has-style\" ><div data-overlay-opactity=\"1\" class=\"panel-row-style panel-row-style-for-65-3\" ><div id=\"pgc-65-3-0\"  class=\"panel-grid-cell\" ><div id=\"panel-65-3-0-0\" class=\"so-panel widget widget_sow-editor panel-first-child panel-last-child\" data-index=\"6\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-editor so-widget-sow-editor-base\"\n\t\t\t\n\t\t>\n<div class=\"siteorigin-widget-tinymce textwidget\">\n\t<h4>Advies<\/h4>\n<p><a href=\"mailto:dirk.parasote@page.be\">dirk.parasote@page.be<\/a>, <a href=\"mailto:ivan@page.be\">ivan@page.be<\/a><br \/>\n<a href=\"mailto:luc@page.be\">luc@page.be<\/a>, <a href=\"mailto:engineering@page.be\">engineering@page.be<\/a>, <a href=\"mailto:bart.lozie@page.Be\">bart.lozie@page.Be<\/a><\/p>\n<h4>Fiducial markers<\/h4>\n<p>Bij voorkeur 3 eilanden diameter 1 mm, in een vrije zone van 2 mm waar liefst geen sporen of mask zit, zoveel mogelijk op hoeken van de print, minimaal 6 mm van de rand van het paneel. Het inverse in een massavlak is ook mogelijk, wel vrij van mask! Bij fine pitch, graag telkens nog eens bij component zelf!<\/p>\n<h4>Processen, in volgorde van kostprijs<\/h4>\n<p><strong>1)<\/strong> <strong>Reflowtechniek:<\/strong> hierdoor kunnen kleine soldeervlakken gebruikt worden, die onder de terminatie van het component komen; de componenten kunnen tot op tienden mm van elkaar komen kost +- 2 eurocent per component, grote componenten en fine pitch componenten kosten vlug 10 tot 20 eurocent om te bestukken; de verpakking is ook een bepalende factor: stick is duurder dan tape, en tray is het duurste.<\/p>\n<p>Reflowtechniek is bijna de perfecte soldeermethode, courant is minder dan 1 fout per 10 000 solderingen, daarmee is het ook de goedkoopste productiemethode geworden.<\/p>\n<p><strong>2)<\/strong> <strong>Bovenkant SMD reflow, onder TH golfsolderen:<\/strong> dit is voor veel printen nog steeds de meest voorkomende productiewijze: typisch voorbeeld: moederbord PC. dit laat toe grote componenten die vaak nog met pinnen zijn, goedkoop en betrouwbaar te monteren, kost: +- 10 eurocent per component, de ontwerpregels zijn vrij evident en hoge kwaliteit is te verwachten!<\/p>\n<p>Wij zien vooral connectoren, vermogencomponenten, elco's in TH (through hole of doorsteekcomponent of klassiek). soms worden smd vlakken en insertiegaten gecombineerd, dit ivm. componentenverkrijgbaarheid, of de kostprijs (elco's).<\/p>\n<p><strong>3) SMD-golfsolderen:<\/strong> met de jaren wordt dit minder populair, algemeen is de soldeerkwaliteit meestal lager dan reflow, het layouten is veel kritischer en de productiestap \"lijm aanbrengen\" en de daaropvolgende bewerkingen zijn veel fout-gevoeliger, ben je bezig met een golf-soldeer layout, stuur gerust een plot door, zodat we ook nog eens een controle kunnen doen!<\/p>\n<p><strong>4) Dubbelzijdig Reflow:<\/strong> dit procede wordt meer en meer gebruikt, toch is het een kostprijsverhogende en kwaliteitsverlagende factor; de componenten krijgen een dubbele thermische belasting (led elco!), componenten van de ene zijde kunnen loskomen tijdens solderen van de andere zijde, print-samenstelling en transportranden worden belangrijker, wij geven graag advies omtrent verdeling van de componenten: onderboven!<\/p>\n<p><strong>5) Handsolderen:<\/strong> duurste montagewijze, te overwegen is steeds: golfsolderen, selectief, of robot <strong>opstartkosten<\/strong> (dossier maken, programma P&amp;P...) en <strong>afroep <\/strong>(herhaalorder) telkens 50 tot 200 eur, dit is vooral afhankelijk van aantal soorten componenten.<\/p>\n<h4>Stencils<\/h4>\n<p>Het stencil is vaak de grootste opstartkost, wij gebruiker tetraflex 23x23 (voorkeur) +-230 euro en 23x29 inch, voor kleine oplagen\/ proto's gebruiken we onze pastajetter (50 tal euro) fine pitch &amp; leadless componenten vergen een dunner stencil (0.1mm), connectors (vervorming), elco's.. , vergen vaak dikker stencil (0.15); voor grote reeksen kan er een speciaal dikte-verlopend stencil besteld worden (dubbele kost voor ets-stencil, 3-voudig electroforeze). Fiducial markers ook voorzien in gerber voor het stencil. Gerber liefst op zelfde maat als pads doorgeven.<\/p>\n<h4>Randen<\/h4>\n<p>2 vrije randen van minimum 4 mm voorzien, voor dubbelzijdig reflow, aan 2 de zijde 6 mm voorzien! Afbreekranden zijn een meerkost, kun je die verwerken in je design, dan is dit meegenomen, we helpen graag meedenken. randen kunnen met breekfrezen of met V-cut (kraslijn) losgemaakt worden.<\/p>\n<h4>Vernissen<\/h4>\n<p>Peters acryllak SL1307N-flz\/18 en SL 1306 (droogtijd enkele dagen) AB Chimie: acryllak AVR 80 BA R DS20 opm: 1307 kunnen we ook aanbrengen met een naald (dikke vernis)<\/p>\n<p>Regels ivm. vernissen:<\/p>\n<ul>\n<li>vernis mo\u00e9t: op alles wat corrosiegevoelig is, zoals pads, pins en via's (bij voorkeur via's gesloten met mask)<\/li>\n<li>vernis verboden: alles wat contact moet maken: contactpin van connector, massavlak op montage gat, aandacht voor connectors en relay's die niet geschikt zijn voor vernissen,<br \/>\nbemerk er is best een speling van 5 tal mm tussen mo\u00e9t vernist \/ verboden vernissen; zijkanten van hoge componenten zijn moeilijk te vernissen, ook risico op spatten; ook aandacht voor gaten in de PCB, vernis kan naar onderkant print vloeien.<\/li>\n<\/ul>\n<p>designrules shapes4.jpg<br \/>\n<a href=\"https:\/\/www.page.be\/Bestukking_Media\/Feducial-markers-IPC.pdf\" target=\"_blank\" rel=\"noopener\">Feducial-markers-IPC.pdf<\/a><br \/>\n<a href=\"https:\/\/www.page.be\/Bestukking_Media\/leds.PDF\" target=\"_blank\" rel=\"noopener\">componenten-info leds.pdf<\/a><br \/>\n<a href=\"https:\/\/page.be\/Bestukking_Media\/reflowtech1.jpg\" target=\"_blank\" rel=\"noopener\">reflowtech1.jpg<\/a><br \/>\nsites: <a href=\"http:\/\/www.pcblibraries.com\" target=\"_blank\" rel=\"noopener\">http:\/\/www.pcblibraries.com<\/a><\/p>\n<\/div>\n<\/div><\/div><\/div><div id=\"pgc-65-3-1\"  class=\"panel-grid-cell\" ><div id=\"panel-65-3-1-0\" class=\"so-panel widget widget_sow-editor panel-first-child panel-last-child\" data-index=\"7\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-editor so-widget-sow-editor-base\"\n\t\t\t\n\t\t>\n<div class=\"siteorigin-widget-tinymce textwidget\">\n\t<h4>Samenstelling of panellisatie<\/h4>\n<p>Voor reeksen van honderdtallen kunnen kleine printen beter samengesteld worden, een print in samenstelling is meestal iets duurder dan een losse print, doch je wint in handelingskosten.<\/p>\n<p>Een zeer goed formaat voor nauwkeurig te kunnen werken is 200-250 x 300 - 400 mm; minimum afmeting print is ongeveer 50 (transportrichting) op 40 mm, maximum is ongeveer 410 op 360, afwijkingen in overleg (bv. kaliber) transportriemen hebben in principe 4 mm nodig; een formaat met veel componenten op werkt kosten-verlagend, omdat iedere productiestap (drukken, solderen, bestukken...) een minimumkost bijbrengt; (we streven naar &gt; 500 cmps\/formaat) printen uit formaat halen kan delicaat zijn, we beschikken over gepaste gereedschappen, van CAB (zie machines en foto-album), bij breekfrezen kun je stevige en gemakkelijk verwijderbare aanhechtingspunten maken (fotoalbum); bij V-cut toch opletten voor ceramische componenten (Caps) die dicht tegen de rand staan, deze kunnen barsten! We geven heel graag advies!<\/p>\n<h4>Bevestigingsgaten<\/h4>\n<p>Vaak zijn er in printen bevestigingsgaten diameter 4-tal mm, met vertind eiland aan boven en onderzijde, en een doorgemetallizeerd gat, bij golfsolderen is er wat werk om deze gaten volledig af te schermen, goedkoop alternatief is de doormetallisatie weglaten, de ringen eventueel voorzien van gerasterd soldeermasker, met eventueel een 4-tal via's erin, diameter koper iets groter dan diameter gat.<\/p>\n<h4>Selectief solderen<\/h4>\n<p>Principieel is dit een flux-fonteintje en een soldeerfonteintje van een diameter van een 3 tot 5-tal mm die via een X-Y-Z as de onderkant van de print afloopt, enkel daar waar er moet gesoldeerd worden; interessant voor SMD printen met nog wat klassieke componenten op, aan dezelfde kant van de SMD's, dit vervangt het duurdere handsoldeerwerk. Er is bij voorkeur 3 mm ver van de \"te solderen vlakken\" geen SMD componenten; in en uitloopzone van 3 tal mm zijn een voordeel. Hoe m\u00e9\u00e9r vrije ruimte hoe sneller we kunnen selectief solderen.<\/p>\n<h4>Soldeerrobot<\/h4>\n<p>We beschikken over 2 soldeerrobots Apolloseiko: zo kunnen we perfect soldeertemperatuur en tijd vastleggen, en op grote reeksen is het goedkoper dan manueel werk, vaak moeten we wel een kaliber maken om de componenten op hun plaats te houden.<\/p>\n<h4>AOI &amp; Testen<\/h4>\n<p>Zie DFM: Tips &amp; Tricks manual en pagina <a href=\"https:\/\/page.be\/electronica\/testen\/\" target=\"_blank\" rel=\"noopener\">testen.<\/a><\/p>\n<h4>Standaard-componenten<\/h4>\n<p>Nu is de 0603 bouwvorm meest populair, goedkoopst en vlotst leverbaar, ook 0402 komt serieus op - Zie pagina <a href=\"https:\/\/page.be\/electronica\/stock\/\" target=\"_blank\" rel=\"noopener\">stock<\/a><\/p>\n<p>Voor weerstanden is de 1206 (= 3x1.5 mm), 0805 en 0603 uit onze voorraad te gebruiken (prijs 2-tal euro per 1000 st) voor ceramiek condensatoren zijn 1206, 0805, 0603 courant (prijs 4-tal euro per 1000 st ) ; bij golfsolderen kunt u soldeervlakken gebruiken die voor beide typen passen voor grote ic's en fine pitch is een correcte tape-stick of tray verpakking zeer belangrijk; voor grote aantallen worden IC's beter op tape aangeleverd (minder manipulatie, minder fouten); graag aanlevering in vochtbeschermende verpakking (MSD)<\/p>\n<h4>Opgieten, producten in gebruik<\/h4>\n<ul>\n<li>Stycast 2651 W1 (mavom)<\/li>\n<li>tecnite <a href=\"http:\/\/www.mavom.com\/\" target=\"_blank\" rel=\"noopener\">http:\/\/www.mavom.com\/<\/a><\/li>\n<li>Dolphon CB1138 zwarte poly-urethane<\/li>\n<li>AXSON RE 22891- (98) epoxy<\/li>\n<\/ul>\n<h4>Lijmen van grote componenten (bv. elco's)<\/h4>\n<p>We hebben dispencegereedschap, gevuld met GLUE REAXYL SK-711, een doorschijnende siliconenlijm, deze lijm droogt in de lucht. Voor hogere stevigheid hebben we een 2 comp: 3M DP490 (duurder)<\/p>\n<h4>Aantallen in toelevering componenten<\/h4>\n<p>Uitval 2% wordt als gemiddelde beschouwd, kan belangrijk zijn voor de kwaliteit van de laatste boards van een reeks, om voldoende reserve in te rekenen!<\/p>\n<h4>Printplaten afwerking<\/h4>\n<p>HAL SN100 is omzeggens de standaard bij ons, uitzonderlijk wordt gekozen voor goud-afwerking. ( &gt;6 laags multilayer, veel fine pitch ivm. vlakheid)<\/p>\n<\/div>\n<\/div><\/div><\/div><\/div><\/div><div id=\"pg-65-4\"  class=\"panel-grid panel-has-style\" ><div data-overlay-opactity=\"1\" class=\"panel-row-style panel-row-style-for-65-4\" ><div id=\"pgc-65-4-0\"  class=\"panel-grid-cell\" ><div id=\"panel-65-4-0-0\" class=\"so-panel widget widget_themegrill_flash_heading tg-widget section-title-wrapper panel-first-child panel-last-child\" data-index=\"8\" >\t<div class=\"heading heading-center divider-without-icon no-divider\">\n\t<h3 class=\"section-title\">DFM: Tips &amp; Tricks Manual Webversie<\/h3>\n\t<div class=\"section-description\">Auteur: Bart Lozie<\/div>\n<\/div>\n<\/div><\/div><\/div><\/div><div id=\"pg-65-5\"  class=\"panel-grid panel-has-style\" ><div data-overlay-opactity=\"1\" class=\"panel-row-style panel-row-style-for-65-5\" ><div id=\"pgc-65-5-0\"  class=\"panel-grid-cell\" ><div id=\"panel-65-5-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"9\" ><div class=\"textwidget custom-html-widget\"><body>\n<div id=\"toc-toggle\"><h1 class=\"TOC-Heading\" id=\"inhoud\">Table of contents<\/h1><\/div>\n<div id=\"floating-toc\">\n<p><a href=\"#colophon\">Colophon\n<span>4<\/span><\/a><\/p>\n<p><a href=\"#the-3-phases-of-production\">The 3 Phases of Production\n<span>5<\/span><\/a><\/p>\n<p><a href=\"#alternative-components\">Alternative Components\n<span>6<\/span><\/a><\/p>\n<p><a href=\"#esd-the-invisible-culprit\">ESD: The Invisible Culprit\n<span>7<\/span><\/a><\/p>\n<p><a\nhref=\"#serial-numbers-and-traceability-in-electronics-manufacturing\">Serial\nNumbers and Traceability in Electronics Manufacturing\n<span>9<\/span><\/a><\/p>\n<p><a href=\"#required-data-for-a-smooth-production-startup\">Required\nData for smooth production startup <span>11<\/span><\/a><\/p>\n<p><a href=\"#component-loss-in-tape-on-reel-smt-parts\">Component Loss in\nTape-On-Reel SMT Parts <span>17<\/span><\/a><\/p>\n<p><a href=\"#electronic-components-and-moisture-sensitivity\">Electronic\nComponents and Moisture Sensitivity <span>19<\/span><\/a><\/p>\n<p><a href=\"#process-sensitivity\">Process sensitivity\n<span>20<\/span><\/a><\/p>\n<p><a href=\"#oxidation\">Oxidation <span>22<\/span><\/a><\/p>\n<p><a href=\"#choice-of-production-technology\">Choice of production\ntechnology <span>23<\/span><\/a><\/p>\n<p><a href=\"#component-selection\">Component selection\n<span>24<\/span><\/a><\/p>\n<p><a href=\"#smt-vs-pth\">SMT vs PTH <span>26<\/span><\/a><\/p>\n<p><a href=\"#v-groove\">V-groove <span>27<\/span><\/a><\/p>\n<p><a href=\"#contact-terminals-finish\">Contact terminals finish\n<span>28<\/span><\/a><\/p>\n<p><a href=\"#gold-embrittlement\">Gold Embrittlement\n<span>29<\/span><\/a><\/p>\n<p><a href=\"#silver-leads\">Silver leads <span>30<\/span><\/a><\/p>\n<p><a href=\"#different-smt-components\">Different SMT components\n<span>31<\/span><\/a><\/p>\n<p><a href=\"#batteries\">Batteries <span>33<\/span><\/a><\/p>\n<p><a href=\"#fiducial-markers\">Fiducial markers <span>35<\/span><\/a><\/p>\n<p><a href=\"#solderpaste-stencil-design\">Solderpaste stencil design\n<span>38<\/span><\/a><\/p>\n<p><a href=\"#special-pad-modifications\">Special pad modifications\n<span>44<\/span><\/a><\/p>\n<p><a href=\"#layer-marking\">Layer marking <span>45<\/span><\/a><\/p>\n<p><a href=\"#silkscreen-design\">Silkscreen design\n<span>46<\/span><\/a><\/p>\n<p><a href=\"#pcb-warpage-bow-twist-bending\">PCB Warpage (bow, twist,\nbending) <span>48<\/span><\/a><\/p>\n<p><a href=\"#pcb-laminate-selection\">PCB laminate selection\n<span>49<\/span><\/a><\/p>\n<p><a href=\"#hole-spacing-for-axial-components\">Hole spacing for axial\ncomponents <span>51<\/span><\/a><\/p>\n<p><a href=\"#permanent-solder-mask\">Permanent solder mask\n<span>52<\/span><\/a><\/p>\n<p><a href=\"#web-vs-window\">Web VS Window <span>53<\/span><\/a><\/p>\n<p><a href=\"#soldermask-on-vias\">Soldermask on via\u2019s\n<span>54<\/span><\/a><\/p>\n<p><a href=\"#x-outs\">X-outs <span>55<\/span><\/a><\/p>\n<p><a href=\"#high-current-design\">High current design\n<span>56<\/span><\/a><\/p>\n<p><a href=\"#bendable-pcbs\">Bendable PCB\u2019s <span>57<\/span><\/a><\/p>\n<p><a href=\"#tin-whiskers\">Tin-whiskers <span>58<\/span><\/a><\/p>\n<p><a href=\"#waterproof\">Waterproof <span>59<\/span><\/a><\/p>\n<p><a href=\"#long-time-storage\">Long time storage\n<span>61<\/span><\/a><\/p>\n<p><a href=\"#ip-protection-intellectual-property\">IP protection\n(intellectual property) <span>64<\/span><\/a><\/p>\n<p><a href=\"#component-supply\">Component supply <span>66<\/span><\/a><\/p>\n<p><a href=\"#vocs\">VOC\u2019s <span>67<\/span><\/a><\/p>\n<p><a href=\"#ultrasonic-welding-of-plastic-housings\">Ultrasonic Welding\nof Plastic Housings <span>68<\/span><\/a><\/p>\n<p><a href=\"#abbreviations\">Abbreviations <span>72<\/span><\/a><\/p>\n<h1 class=\"dfm\" id=\"section\"><\/h1>\n<\/div>\n<h1 class=\"dfm\" id=\"colophon\">Colophon<\/h1>\n<p>This booklet was written for the customers of Page Electronica NV and\naddresses common design-related issues. Through close and accessible\ncommunication between the production facility and the R&amp;D\ndepartment, we strive to maximize the manufacturability of a PCB\nassembly.<\/p>\n<p>High manufacturability ensures a cost-effective and highly reliable\nproduct.<\/p>\n<p>We have deliberately avoided going too much into technical detail in\norder to keep the booklet readable. If you have any questions, please\nfeel free to contact the process engineer for tailored advice.<\/p>\n<p>Contact: <a\nhref=\"mailto:bart.lozie@page.be\">bart.lozie@page.be<\/a><\/p>\n<p>Process engineer.<\/p>\n<h1 class=\"dfm\" id=\"the-3-phases-of-production\">The 3 Phases of Production<\/h1>\n<p><strong>Prototype (\u03b1-series)<br \/>\n<\/strong>A prototype is an early model of a product, often partially\nassembled by hand, used to test the functionality or fit of components.\nTo reduce costs and keep lead times short, it is a deliberate choice not\nto manufacture everything fully automatically at this stage.<br \/>\nHowever, do not assume that a functioning prototype proves that the\ndesign is ready for mass production.<\/p>\n<p><strong>Pilot Run (\u03b2-series)<br \/>\n<\/strong>After successfully completing the prototype phase, a pilot run\nis produced to verify whether the products meet all specifications and\ntesting protocols as defined. During this phase, the various production\nprocesses are carried out as completely as possible and fine-tuned. The\npilot run offers a more representative view of the eventual series\nproduction process.<\/p>\n<p><strong>Series Production<br \/>\n<\/strong>Following the prototype and pilot phases comes the actual\nseries production. At this stage, we aim for the highest possible degree\nof automation. The focus is on minimizing the cost per unit and\nmaximizing production yield.<\/p>\n<h1 class=\"dfm\" id=\"alternative-components\">Alternative Components<\/h1>\n<p><strong>Long-Term Availability and Component Lifecycle\nManagement<\/strong><\/p>\n<p>Unlike consumer electronics, service products are expected to offer\nreplacement availability over an extended period. In sectors such as\nmachinery and infrastructure, a replacement market lifespan of 15 years\nor more is often required.<\/p>\n<p>However, the market for electronic components evolves rapidly, driven\nlargely by the consumer electronics industry and its push for extreme\nminiaturization. As a result, components may become obsolete or\nunavailable much sooner.<\/p>\n<p>To ensure long-term product continuity, designers must take into\naccount the availability of alternative components and monitor the\nend-of-life (EOL) status of selected parts. This should already be\nconsidered during the design phase.<\/p>\n<p>A reliable EMS (Electronics Manufacturing Services) partner will\nmanage this process together with the designer, actively monitoring the\nEOL status of all components to initiate last-time buys, alternative\npart selection, or PCB redesign in a timely manner.<\/p>\n<p>When it comes to alternative components, we distinguish two main\ncategories:<\/p>\n<ul>\n<li><p><strong>Function Compatible<\/strong>: The component provides the\nsame functionality and is electrically suitable, but may differ in\nphysical characteristics.<\/p><\/li>\n<li><p><strong>Form-Fit-Function Compatible<\/strong>: The alternative is\nelectrically identical and also matches the original component\u2019s\nfootprint and physical dimensions.<\/p><\/li>\n<\/ul>\n<h1 class=\"dfm\" id=\"esd-the-invisible-culprit\">ESD: The Invisible Culprit<\/h1>\n<p>All non-conductive materials become electrically charged through\nfriction with other materials in the triboelectric series. Everyone is\nfamiliar with the static shock felt when getting out of a car, combing\nhair, or the crackling sound when pulling on a woolen sweater.<\/p>\n<p>Static discharges can reach voltages of over 50,000V. While this is\nmerely unpleasant for humans, electronic chips\u2014often sensitive to ESD at\nlevels below 100V\u2014can be severely damaged.<\/p>\n<p>Damage caused to electronic chips by static discharge is called\nElectrical Overstress, or EOS.<\/p>\n<p>It is important to understand that EOS damage caused by ESD is not\nalways immediately apparent as chip failure. Instead, EOS can cause tiny\nburn spots inside the chip that may lead to premature failure months\nlater.<\/p>\n<p>Just as hand hygiene and wearing hairnets are mandatory and standard\npractice in the food industry, the electronics sector is obligated to\nwork in an ESD-safe manner. The basic rule is simple and twofold:<\/p>\n<ul>\n<li><p>Everything conductive must be grounded.<\/p><\/li>\n<li><p>Everything insulating, which can generate charge, must be kept\nout of the ESD-protected area (EPA).<\/p><\/li>\n<\/ul>\n<p>The human body is conductive, but our shoes are often insulating. To\ncomply with the above rule, we must ground ourselves by wearing ESD\nshoes or grounding straps on the feet or wrist.<br \/>\nA wrist strap is mandatory when not standing directly on the ground, as\ngrounding through the feet is then lost.<\/p>\n<p>Our clothing, especially nylon, is insulating. It is best to keep\nnylon clothing (e.g., sportswear) out of the EPA.<br \/>\nIf you wear insulating clothing underneath, cover it with ESD-safe\nclothing (Faraday cage principle). In other words, the outermost layer\nof clothing must be ESD-safe and enclose the other layers.<\/p>\n<p>We strive to minimize insulating materials in the EPA: plastic bins\nare replaced by black conductive plastic bins, work surfaces are\nequipped with grounded conductive mats, packaging materials are\npurchased in dissipative versions, and so on.<\/p>\n<p>Below you can see an example of LATI polymer material, which does not\naccumulate static charge, and ASA polymer material, which does.<\/p>\n<table style=\"width:100%;\">\n<colgroup>\n<col style=\"width: 99%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image1.png\"\nstyle=\"width:4.89583in;height:2.89961in\"\nalt=\"Afbeelding met tekst, horloge, elektronica, klok Automatisch gegenereerde beschrijving\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\"\nid=\"serial-numbers-and-traceability-in-electronics-manufacturing\">Serial\nNumbers and Traceability in Electronics Manufacturing<\/h1>\n<p><strong>Introduction<\/strong><\/p>\n<p>In today\u2019s electronics industry, <strong>traceability<\/strong>\u2014the\nability to track products and components throughout the entire\nproduction chain\u2014is a vital part of quality management and process\ncontrol. Serial numbers play a central role in this system: they provide\nthe <strong>unique identification<\/strong> that allows each product,\ncomponent, or batch to be traced from basic material to end user.<\/p>\n<p><strong>Function of Serial Numbers<\/strong><\/p>\n<p>A serial number is a <strong>unique code<\/strong> assigned to each\nindividual product or assembly. This code makes it possible to:<\/p>\n<ul>\n<li><p>Differentiate products within the same product family.<\/p><\/li>\n<li><p>Link production and test data to a specific item.<\/p><\/li>\n<li><p>Handle potential defects, failures, or recalls (RMAs) quickly and\naccurately.<\/p><\/li>\n<\/ul>\n<p>In electronics manufacturing, serial numbers are automatically\ngenerated and printed on labels or directly <strong>laser-marked onto\nthe printed circuit board (PCB)<\/strong>. They are recorded in the\nManufacturing Execution System (MES) or ERP system, together with all\nrelevant production data.<\/p>\n<p>At <strong>Page Electronica<\/strong>, we are transitioning from using\nserial numbers on labels to <strong>laser-marked serial numbers directly\non the PCB<\/strong>. In this process, a small area of the solder mask is\npartially removed. Although the coating is not completely stripped, our\npreference is to mark within a <strong>copper-free area<\/strong>,\navoiding any zones that contain tracks.<\/p>\n<p><strong>Data Structure<\/strong><\/p>\n<p>The serial number is applied as a <strong>2D DataMatrix ECC200\ncode<\/strong>, and where space allows, it is also printed in\nhuman-readable format. The code contains both the <strong>production lot\nnumber<\/strong> and a <strong>unique serial number<\/strong>.<\/p>\n<p>The minimum marking area is <strong>5 x 5 mm<\/strong>; for legible\nhuman-readable text, a <strong>clearance area of at least 6 x 6\nmm<\/strong> is required. Preferring a copper and silk free zone as\nmentioned above.<\/p>\n<p><strong> are available:<\/strong><\/p>\n<table>\n<colgroup>\n<col style=\"width: 33%\" \/>\n<col style=\"width: 34%\" \/>\n<col style=\"width: 32%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image2.png\"\nstyle=\"width:1.91198in;height:1.73747in\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image3.png\"\nstyle=\"width:2.02714in;height:1.74341in\"\nalt=\"Afbeelding met cirkel Door AI gegenereerde inhoud is mogelijk onjuist.\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image4.png\"\nstyle=\"width:1.60588in;height:1.72632in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">1<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<td style=\"text-align: center;\">3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ol type=\"1\">\n<li><p>A unique datamatrix Sn\u00b0, on a thermal and wash resistant label,\nthe minimum needed free space = 7x7mm<\/p><\/li>\n<li><p>A laser marked datamatrix (preferred) containing a unique Sn\u00b0 and\nthe batch number + readable text, the min needed space is\n6x6mm.<\/p><\/li>\n<li><p>A laser marked datamatrix containing a unique Sn\u00b0 and the batch\nnumber, there is no readable text. The min free area is 5x5mm<\/p><\/li>\n<\/ol>\n<p><strong>Traceability Levels<\/strong><\/p>\n<p>Traceability can be implemented at various levels:<\/p>\n<ol type=\"1\">\n<li><p><strong>Component level<\/strong> \u2013 Each electronic component\n(such as ICs or capacitors) is linked to a supplier, batch number, and\npurchase order.<\/p><\/li>\n<li><p><strong>PCB level<\/strong> \u2013 Each printed board assembly (PBA)\nreceives a unique serial number used to store production parameters,\ntest results, and software versions.<\/p><\/li>\n<li><p><strong>System level<\/strong> \u2013 The final product is assigned an\noverarching serial number that links all related subassemblies.<\/p><\/li>\n<\/ol>\n<p><strong>Benefits of Traceability<\/strong><\/p>\n<p>A well-implemented traceability system provides numerous\nadvantages:<\/p>\n<ul>\n<li><p><strong>Quality assurance:<\/strong> rapid identification and\ntracking of deviations or customer complaints.<\/p><\/li>\n<li><p><strong>Process optimization:<\/strong> analysis of production\ndata to identify trends or recurring issues.<\/p><\/li>\n<li><p><strong>Compliance:<\/strong> adherence to standards such as ISO\n9001, IPC-610, J-STD, and others.<\/p><\/li>\n<li><p><strong>Efficiency in service and warranty:<\/strong> simplified\nidentification of products in the field.<\/p><\/li>\n<\/ul>\n<h1 class=\"dfm\" id=\"required-data-for-a-smooth-production-startup\">\u00a0Required Data\nfor a smooth production startup<\/h1>\n<p>Please provide the <strong>IPC inspection class<\/strong> of your\nproduct, (IPC Class I: consumer products, Class II: service\/industrial\nproducts, Class III: high-reliability and critical products).<\/p>\n<p>This is important to determine what section of the production\nstandard the assembly needs to comply with.<\/p>\n<p><strong>Revision and Documentation<\/strong><\/p>\n<p>Provide clear information regarding the current product revision, the\nrevision buildup and revision history as the EMS-contractor needs to\ncreate a comparison between its own revision buildup and the one of the\ncustomer.<\/p>\n<p><strong>Bill of Materials (BOM)<\/strong><\/p>\n<p>A <strong>Bill of Materials<\/strong> for electronic assembly is a\nstructured list that defines all components required to build an\nelectronic product. A complete and production-ready BOM for PCB assembly\n(PCBA) typically includes the following elements:<\/p>\n<ul>\n<li><p>Item \/ Line Number<\/p><\/li>\n<li><p>Quantity per Board<\/p><\/li>\n<li><p>Reference Designators (e.g., R3, C12, U1)<\/p><\/li>\n<li><p>Component Description (e.g., \u201c10 k\u03a9 1% 0603 resistor\u201d)<\/p><\/li>\n<li><p>Manufacturer Name<\/p><\/li>\n<li><p>Manufacturer Part Number (MPN)<\/p><\/li>\n<li><p>Internal Part Number (if applicable)<\/p><\/li>\n<\/ul>\n<p><strong>Alternative Part List<\/strong><\/p>\n<p>An <strong>Alternative Part List<\/strong> contains substitute\ncomponents for an original part. These alternatives may be used when the\nprimary component is unavailable, obsolete, has a long lead time, or\nwhen cost reduction is desired.<\/p>\n<p>Alternative parts are typically defined in two categories:<\/p>\n<ul>\n<li><p><strong>Equivalent Parts<\/strong> \u2013 fully interchangeable with\nthe original component, <strong>with identical form, fit, and\nfunction<\/strong>.<\/p><\/li>\n<li><p><strong>Alternate Parts<\/strong> \u2013 interchangeable but with\ncertain considerations (e.g., a capacitor with a different voltage\nrating or tolerance).<\/p><\/li>\n<\/ul>\n<p>Selecting suitable alternatives requires verifying electrical\ncompatibility, mechanical fit, and manufacturability, as well as\nconsidering cost, availability, and supply-chain stability. In some\ncases, consultation with component manufacturers or distributors may be\nnecessary.<\/p>\n<p><strong>PSL Process Sensitivity Levels<br \/>\n<\/strong>Some components cannot be processed using standard methods\nbecause, for example, they are not resistant to reflow process\ntemperatures or the usual cleaning agents, or they are sensitive to\ncontamination by VOC\u2019s... These are often sensitive sensors, LEDs, or\nhigh-capacity capacitors.<br \/>\nIf you are aware that certain components are process-sensitive, please\nmake sure to communicate this information to the production facility to\nprevent it from being overlooked.<\/p>\n<p><strong>Component Mechanical Datasheets<\/strong><\/p>\n<p>Many components have standardized package formats, such as 0402 and\n0603 square chip components, or the complete Philips series including\nSOT23, SOT89, SO-8, and others.<br \/>\nNowadays, however, many highly specific, unique, and odd-shaped packages\nare also being produced. LEDs and PCB-on-PCB modules are typical\nexamples of this trend.<br \/>\nPlease provide the mechanical datasheets for these components if they\nare difficult to find online.<\/p>\n<p><strong>GERBER RS-274-X (Extended Gerber)<\/strong><\/p>\n<p>RS-274-X is the most widely used file format for PCB manufacturing.\nAlthough there are substitutes like ODB++ that contain more data then\nGerber, still gerbers is the main used format for production\npreparation. <strong>Always specify the required PCB thickness and\nspecial laminate requirements if any.<\/strong><\/p>\n<p><strong>ODB++ (Siemens-Valor)<\/strong><\/p>\n<p>Siemens pushes the marked to obtain their new ODB++ standard,\nunfortunate this pushes the EMS-contractor to use exclusively rather\nexpensive Siemens software. Other software sometimes can handle ODB++\nfiles but only if exported with units standard set as imperial-inch.<\/p>\n<p><strong>PCB Manufacturer Working Files<\/strong><\/p>\n<p>These are the editable production files created by the PCB\nfabrication engineer.<br \/>\nCompared to the original Gerber files, manufacturer working files also\ninclude additional data such as:<\/p>\n<ul>\n<li><p>Breakaway and panelization details (e.g., rails, tabs, mouse\nbites)<\/p><\/li>\n<li><p>Added tooling features (fiducials, tooling holes,\ncoupons)<\/p><\/li>\n<li><p>Manufacturing-specific adjustments and process notes<\/p><\/li>\n<\/ul>\n<p>These files represent the version used directly for PCB production\nand may differ slightly from the customer-supplied data to ensure\nmanufacturability.<\/p>\n<p><strong>Insert File<\/strong><\/p>\n<p>An insert file in electronics manufacturing is a data file that\ninstructs the pick-and-place robots where and how to place each\ncomponent on the PCB. It typically contains:<\/p>\n<ul>\n<li><p>Component identifiers (reference designators, e.g., R1, C5, U3) -\nComponent designaters shall be limited to 5 characters. (e.g.\nIC123)<\/p><\/li>\n<li><p>X\/Y coordinates on the PCB<\/p><\/li>\n<li><p>Rotation angle of each component<\/p><\/li>\n<li><p>Component type \/ package (e.g., 0402, SOT-23, QFN)<\/p><\/li>\n<li><p>Optional machine-specific details such as component height and\nnozzle selection<\/p><\/li>\n<\/ul>\n<p>Insert files are usually generated from the PCB design software and\nthen adapted to the format required by the specific placement machine.\nThis ensures that the machine can accurately and automatically place\ncomponents in their correct positions on the PCB.<\/p>\n<p><strong>IPC-D-356A<\/strong><\/p>\n<p>IPC-D-356 is an electronic netlist format used to unambiguously\ndescribe the electrical connections of a PCB.<\/p>\n<p>It contains information about which pads and component pins should be\nelectrically connected, including test points and sometimes impedance or\nreference information.<\/p>\n<p>IPC-D-356 is used to verify that the produced board matches the\ndesign electrically, typically through a netlist comparison. Machines\nsuch as Flying probe testers are programmed using this file format.<\/p>\n<p><strong>IPC-2581 (optional)<\/strong><\/p>\n<ul>\n<li><p>Open, XML-based format for exchanging complete PCB data.<\/p><\/li>\n<li><p>Contains all information required for production, assembly, and\ninspection, including layers, stack-up, dimensions, drills, netlist,\ncomponent data, BOM, test points, and more.<\/p><\/li>\n<\/ul>\n<p><strong>Specification of Special Instructions<\/strong><\/p>\n<p>In <strong>IPC-A-610<\/strong>, the term <strong>\u201cNot\nEstablished\u201d<\/strong> indicates that <strong>no acceptance criteria have\nbeen defined<\/strong> for a particular feature. In other words, the\nstandard does not specify whether the feature is acceptable,\nunacceptable, or allowable.<\/p>\n<p>This does <strong>not<\/strong> mean that anything is automatically\nacceptable \u2014 it simply means that IPC-A-610 does not provide guidance\nfor that specific characteristic.<\/p>\n<p>For such cases, requirements must be agreed upon between the customer\nand the EMS provider. <em>These special instructions should be clearly\ndescribed.<\/em><\/p>\n<p><strong>Examples<\/strong><\/p>\n<ul>\n<li><p>Specifying torque values for screw connections<\/p><\/li>\n<li><p>Any mechanical assembly requirements not covered by\nIPC-A-610<\/p><\/li>\n<li><p>Special coating, handling, or inspection instructions<\/p><\/li>\n<\/ul>\n<p><strong>Assembly Drawing<\/strong><\/p>\n<p>Supply a clear assembly drawing containing at least the following\ninformation:<\/p>\n<ul>\n<li><p><strong>Pin-1 indication<\/strong> for components such as ICs and\nconnectors.<\/p><\/li>\n<li><p><strong>Reference designators (REFDES)<\/strong> for all\ncomponents and unambiguous <strong>polarity markings<\/strong> (e.g.,\ncathode indication). It is recommended to show these on the assembly\ndrawing rather than relying solely on the silkscreen layer.<\/p><\/li>\n<li><p><strong>Guidelines for AXI (Automated X-ray Inspection)<\/strong>:\nspecify which components require X-ray inspection and the desired sample\nrate. Note that AXI is <em>not<\/em> mandatory under IPC-A-610.<\/p><\/li>\n<li><p><strong>Special handling and ESD requirements<\/strong>:<\/p>\n<ul>\n<li><p>Clearly mark ultra-sensitive <strong>Class 0 ESD\ncomponents<\/strong>, so additional precautions can be taken.<\/p><\/li>\n<li><p>Standard electronics manufacturing environments are typically\n<strong>Class 1 compatible only<\/strong>, unless otherwise\nspecified.<\/p><\/li>\n<\/ul><\/li>\n<\/ul>\n<p><strong>Testing<\/strong><\/p>\n<p>The customer may supply their own test system, or we as\nEMS-contractor can design and build a complete in-house solution. Both\noptions are briefly discussed below, for more information contact the\nFAB-engineering.<\/p>\n<p><strong>Test system developed by the EMS contractor<\/strong><\/p>\n<p>Involves test-coverage analysis, hardware and software development,\nintegration with traceability and validation.<\/p>\n<p>The following items are necessary:<\/p>\n<ul>\n<li><p>Testpoint report: list of all testpoints and their\nfunction.<\/p><\/li>\n<li><p>Manufacturing data: PCB (Gerbers) and schematic.<\/p><\/li>\n<li><p>One functional (prototype) PCBA (single board or in\ncluster\/panel).<\/p><\/li>\n<\/ul>\n<p>Additionally the EMS-contractor offers Design-for-Test (DFT) support,\nassisting the PCB engineer in optimizing their design for\ntestability.<\/p>\n<p><strong>Test system developed by customer and used in EMS\nFAB<\/strong><\/p>\n<p>Due to cybersecurity regulations (NIS2), external, unauthorized\nnetwork devices are generally prohibited. Depending on the requirements\nthe following options are possible:<\/p>\n<ol type=\"1\">\n<li><p>The customer may supply their own hardware (e.g. laptop) only if\nnetwork connection is not in any case required at the production\nsite.<\/p><\/li>\n<li><p>For testing in the project\u2019s initial phase that require network\nconnection, the EMS-contractor can provide a 4G\/5G modem. This creates\nan isolated network, which is not architected to be used in mass\nproduction.<\/p><\/li>\n<li><p>The FAB offers a dedicated server for functional testing in mass\nproduction. In consultation with the customer, a Virtual Machine is made\navailable with network access. The necessary software and tools are\ninstalled and configured on the VM.<\/p><\/li>\n<\/ol>\n<p><strong>Conformal Coating Heatmap<\/strong><\/p>\n<p>Provide a <strong>heatmap for conformal coating<\/strong> that clearly\nindicates:<\/p>\n<ul>\n<li><p><strong>Mandatory coating areas:<\/strong> zones that must be\ncovered with conformal coating.<\/p><\/li>\n<li><p><strong>Exclusion areas:<\/strong> zones that must remain free of\ncoating (e.g., switches, sensors, connectors).<\/p><\/li>\n<li><p><strong>Optional coating areas:<\/strong> zones where coating may\nbe applied at the manufacturer\u2019s discretion.<\/p><\/li>\n<\/ul>\n<p>The heatmap should be precise and easy to interpret, ensuring the\nassembly team applies the coating accurately according.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image5.png\"\nstyle=\"width:5.125in;height:2.88168in\"\nalt=\"Afbeelding met tekst, Plan, kaart, diagram Door AI gegenereerde inhoud is mogelijk onjuist.\" \/><\/p>\n<h1 class=\"dfm\" id=\"component-loss-in-tape-on-reel-smt-parts\">Component Loss in\nTape-On-Reel SMT Parts<\/h1>\n<p>SMT components are becoming increasingly smaller, sometimes barely\nvisible to the naked eye. The vast majority of electronic components no\nlonger have identification markings or text indicating their type.\nLarger components often have fragile leads or solder points, making\nreuse risky. Together, these factors mean we cannot assume SMT\ncomponents can be placed manually.<\/p>\n<p>SMT components, in all their diversity, must be supplied to the\nplacement machine using feeders. Feeders open the component pockets and\nfeed the machine with a new component after each pick-up.<\/p>\n<p>Each setup requires loading the feeders, during which 1 to 2\ncomponents can be lost. Additionally, when unloading the feeder\u2014if the\nreel is not fully used and production ends\u20142 components are inevitably\nlost.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image6.png\"\nstyle=\"width:3.72929in;height:2.60684in\"\nalt=\"Afbeelding met metaal, harde schijf, zilver, overdekt Automatisch gegenereerde beschrijving\" \/><\/p>\n<p><strong>Pick &amp; Place Robots<\/strong><\/p>\n<p>Pick &amp; Place robots quickly pick up and place these tiny\ncomponents\u2014sometimes at rates exceeding 20 components per second. This\nmeans the machine picks up 20 components every second, then checks their\ndimensions, corrects their position and rotation, and finally places\nthem on the printed circuit board.<\/p>\n<p>To maintain these high speeds, modern placement machines are designed\nto immediately reject and discard any component that deviates in size.\nThis process is called <strong>machine spit-out<\/strong>.<\/p>\n<p>Depending on the geometric complexity of the component, machine\nspit-out typically ranges between 0.05% and 0.20%.<\/p>\n<h1 class=\"dfm\" id=\"electronic-components-and-moisture-sensitivity\">Electronic\nComponents and Moisture Sensitivity<\/h1>\n<p>Electronic components, especially plastic-molded SMT parts, are\nsensitive to moisture. Plastics are hygroscopic and absorb moisture from\nthe air. When heated during the assembly process, the built-up pressure\nfrom trapped moisture can cause damage to the sensitive elements of the\ncomponent.<\/p>\n<p>The pressure from water vapor increases exponentially with rising\ntemperature and becomes problematic for electronic components once\ntemperatures exceed 200\u00b0C.<\/p>\n<p>Damage to components or PCBs can vary and may include cracked\nsilicone seals, delaminated bonding, twisted components causing\nsoldering defects, blowholes, blisters, and more.<\/p>\n<p>The factory closely follows the JEDEC J-STD-020 standard for\nsoldering moisture-sensitive components.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image7.png\"\nstyle=\"width:3.60507in;height:2.42735in\"\nalt=\"Afbeelding met tekst, schermopname, nummer, Lettertype Automatisch gegenereerde beschrijving\" \/><\/p>\n<h1 class=\"dfm\" id=\"process-sensitivity\">Process sensitivity<\/h1>\n<p>To understand the process parameters for semiconductor components,\ndatasheets are thoroughly reviewed. In most cases, the datasheet\nincludes a dedicated section on the recommended process\nparameters.<br \/>\nFor non-IC components, the situation is somewhat different; these\ndatasheets are often brief and rarely contain the necessary\nprocess-related technical information.<br \/>\nThe standard J-STD-075 defines PSL (process sensitivity levels) for\nnon-semiconductor electronic components and categorizes them into\ncomponent families.<\/p>\n<p>Pt: Preheating temperature<br \/>\nTL: Time in liquidus<br \/>\nTp: Peak temperature<br \/>\nTpt: Time within 5\u00b0C of the peak temperature<br \/>\n#Reflows: Maximum allowed number of reflow cycles<br \/>\n** Temperature measured at the top-center of the component.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 21%\" \/>\n<col style=\"width: 18%\" \/>\n<col style=\"width: 17%\" \/>\n<col style=\"width: 17%\" \/>\n<col style=\"width: 12%\" \/>\n<col style=\"width: 12%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><\/th>\n<th style=\"text-align: center;\"><strong>Pt<\/strong><\/th>\n<th style=\"text-align: center;\"><strong>Tl<\/strong><\/th>\n<th style=\"text-align: center;\"><strong>Tp<\/strong><\/th>\n<th style=\"text-align: center;\"><strong>Tpt<\/strong><\/th>\n<th style=\"text-align: center;\"><strong># reflow<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">Alu Elcap D \u2264 6.3mm H \u2264 4.5mm<\/td>\n<td style=\"text-align: center;\">100 \u2013 150\u00b0C (90s)<\/td>\n<td style=\"text-align: center;\">30s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">240\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Alu Elcap D \u2264 6.3mm H &gt; 4.5mm<\/td>\n<td style=\"text-align: center;\">100 \u2013 150\u00b0C (90s)<\/td>\n<td style=\"text-align: center;\">30s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">250\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Alu Elcap D &gt; 6.3mm \u2264 10mm<\/td>\n<td style=\"text-align: center;\">100 \u2013 150\u00b0C (90s)<\/td>\n<td style=\"text-align: center;\">20s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">240\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Alu Elcap D &gt; 10mm<\/td>\n<td style=\"text-align: center;\">100 \u2013 150\u00b0C (120s)<\/td>\n<td style=\"text-align: center;\">20s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">230\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Plastic molded alu caps H \u2265 1.8mm &lt;\n12.5Volt<\/td>\n<td style=\"text-align: center;\">180\u00b0C max (120s)<\/td>\n<td style=\"text-align: center;\">60s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">250\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Plastic molded alu caps H \u2265 1.8mm \u2265\n12.5Volt<\/td>\n<td style=\"text-align: center;\">180\u00b0C max (120s)<\/td>\n<td style=\"text-align: center;\">30s &gt;200\u00b0C<\/td>\n<td style=\"text-align: center;\">240\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">1<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Plastic molded alu caps H \u2264 1.1mm<\/td>\n<td style=\"text-align: center;\">180\u00b0C max (120s)<\/td>\n<td style=\"text-align: center;\">30s &gt;200\u00b0C<\/td>\n<td style=\"text-align: center;\">240\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Film cap PPS<\/td>\n<td style=\"text-align: center;\">180\u00b0C max (120s)<\/td>\n<td style=\"text-align: center;\">30s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">260\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Film cap non-PPS<\/td>\n<td style=\"text-align: center;\">180\u00b0C max (120s)<\/td>\n<td style=\"text-align: center;\">30s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">240\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Plastic mould Polymer Tantalum cap \u2264\n10Volt<\/td>\n<td style=\"text-align: center;\">180\u00b0C max (120s)<\/td>\n<td style=\"text-align: center;\">40s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">250\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Plastic mould Polymer Tantalum cap &gt;\n10Volt<\/td>\n<td style=\"text-align: center;\">180\u00b0C max (120s)<\/td>\n<td style=\"text-align: center;\">30s &gt;217\u00b0C<\/td>\n<td style=\"text-align: center;\">250\u00b0C<\/td>\n<td style=\"text-align: center;\">5s<\/td>\n<td style=\"text-align: center;\">2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Xtal oscillators<\/td>\n<td style=\"text-align: center;\">120s<\/td>\n<td style=\"text-align: center;\">90s<\/td>\n<td style=\"text-align: center;\">250\u00b0C<\/td>\n<td style=\"text-align: center;\">10s<\/td>\n<td style=\"text-align: center;\">-<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Fuses<\/td>\n<td style=\"text-align: center;\">85s<\/td>\n<td style=\"text-align: center;\">65s<\/td>\n<td style=\"text-align: center;\">Zie Specs<\/td>\n<td style=\"text-align: center;\">20s<\/td>\n<td style=\"text-align: center;\">-<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Inductors with insulated wires<\/td>\n<td style=\"text-align: center;\">100 \u2013 150\u00b0C (90s)<\/td>\n<td style=\"text-align: center;\">60s<\/td>\n<td style=\"text-align: center;\">Zie Specs<\/td>\n<td style=\"text-align: center;\">20s<\/td>\n<td style=\"text-align: center;\">-<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Non-solid state relais<\/td>\n<td colspan=\"5\" style=\"text-align: center;\">Apply to specs<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Leds<\/td>\n<td colspan=\"5\" style=\"text-align: center;\">Apply to specs<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"oxidation\">Oxidation<\/h1>\n<p>Metals are sensitive to oxidation, which can occur in various forms\nand degrees and is not always detrimental. For example, tin, corten\nsteel, or stainless steel form an oxide layer that protects the\nunderlying metal from further corrosion.<br \/>\nThe tin oxide layer changes color depending on its thickness. During\nreflow soldering, the warm air can cause oxidation on metal parts that\nare not in contact with solder fluxes.<\/p>\n<ul>\n<li><p>Up to 10 nanometers: transparent<\/p><\/li>\n<li><p>10\u201315 nm: yellowish<\/p><\/li>\n<li><p>15\u201320 nm: yellow-blue<\/p><\/li>\n<li><p>20\u201330 nm: blue<\/p><\/li>\n<li><p>30\u201350 nm: purple<\/p><\/li>\n<li><p>Over 50 nm: black<\/p><\/li>\n<\/ul>\n<p>Up to 15 nm, there is little to no problem; once thicker, this can\nhinder the formation of a proper connection.<\/p>\n<p>Metal oxides are generally less conductive; however, AgO\u2082 is actually\nmore conductive than Ag.<br \/>\nCorrosion occurs when the metal degrades and loses its properties as a\nresult of oxidation. This is often in combination with a catalyst, such\nas water, salty air near the coast, sulfur near industrial areas, or\nammonia near intensive agriculture and livestock farming.<br \/>\nDue to the nature of electronic soldering, it is particularly\nsusceptible to corrosion. In galvanic and electrolytic corrosion, an\nadditional electrical voltage acts as a catalyst, accelerating deep\ncorrosion.<\/p>\n<p>Aqueous cleaning can also promote oxidation, so it is important to\nuse additional corrosion inhibitors and ensure an efficient drying\ncycle.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image8.png\"\nstyle=\"width:3.18842in;height:2.53347in\"\nalt=\"Afbeelding met Passief stroomkringonderdeel, Elektronische engineering, Elektronisch onderdeel, Stroomkringonderdeel Door AI gegenereerde inhoud is mogelijk onjuist.\" \/><\/p>\n<h1 class=\"dfm\" id=\"choice-of-production-technology\">Choice of production technology\n<\/h1>\n<p>The choice of production technology will determine how the final\nassembly is carried out. There are numerous methods to create electrical\nand mechanical connections, and it is advisable to consider the\nfollowing points.<\/p>\n<p>We distinguish several connection techniques: SMT reflow soldering,\nSMT wave soldering, PTH wave soldering, miniwave soldering (selective\nsoldering), robot soldering, wire soldering, pin-in-paste soldering,\npress-fit connections, bonding using (anisotropic) conductive adhesives,\nand thermode soldering.<\/p>\n<p>The price, durability, and control of the technology on the factory\nfloor will influence the choice. You can combine multiple techniques,\nbut each production step adds setup costs and increases production lead\ntime.<\/p>\n<h1 class=\"dfm\" id=\"component-selection\">Component selection<\/h1>\n<p><strong>SMT offers higher yield and lower cost than PTH\nsoldering<\/strong>, but only if all SMT components can be placed by\nmachine. SMT parts that require manual placement due to packaging or\ncomplex geometry will result in lower yield.<\/p>\n<p><strong>Avoid using SMT connectors<\/strong> for applications\ninvolving repeated or heavy mechanical stress, as SMT solder joints have\nlimited mechanical strength. PTH soldering performs significantly better\nin such cases.<\/p>\n<p><strong>Avoid components that require a specific production\nprocess<\/strong>, such as a single SMT part on an otherwise PTH board or\nvice versa. These create an additional and preferably avoidable\nproduction step.<\/p>\n<p>Do not use chip components \u22640603 for SMT wave soldering.<\/p>\n<p>Do not miniaturize unnecessarily. Follow component market trends that\nsuit your product.<\/p>\n<p><strong>Reduce the number of different components<\/strong>. Check\nwhether certain parts can be replaced with values already used elsewhere\n\u2014 not just across the board, but also per side. Moving a component to\nanother side may reduce setup costs.<\/p>\n<p><strong>Avoid flexible connections<\/strong>. Flexible connections are\nsignificantly less reliable than fixed connections.<\/p>\n<p><strong>PIP soldering<\/strong> is only effective up to a PCB\nthickness of 1.6\u202fmm.<\/p>\n<h2 id=\"section-1\"><\/h2>\n<p><strong>Temp stress graph<\/strong><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image9.png\"\nstyle=\"width:6.36632in;height:4.60917in\"\nalt=\"Afbeelding met lijn, Perceel, diagram, helling Door AI gegenereerde inhoud is mogelijk onjuist.\" \/><\/p>\n<h1 class=\"dfm\" id=\"smt-vs-pth\">SMT vs PTH<\/h1>\n<p>Surface mount technology (SMT) offers higher yield and lower assembly\ncosts compared to pin-through-hole (PTH) technology. Assembly costs for\nSMT components are often only about one-tenth of those for PTH\ncomponents.<\/p>\n<p>However, this applies only if all SMT components can be placed by\nmachines. SMT parts that require manual placement due to awkward\npackaging, complex shapes, or large sizes tend to result in lower yields\nand create bottlenecks in the production line.<\/p>\n<p>Reduce the number of different components by checking if parts can be\nreplaced with existing component values or packages. Do this not only\nfor the PCB but also for each assembly side, as moving a component to\nthe other side can reduce setup costs.<\/p>\n<p><strong>SMT in conventional wave soldering<\/strong><br \/>\nSMT in conventional wave soldering is highly design-sensitive and\nsubjects components to significant thermal shock, so it is strongly\ndiscouraged.<br \/>\nDo not use chip components \u22640603 in SMT wave soldering. Avoid\nunnecessary miniaturization and follow the component market trends for\nyour product.<\/p>\n<p><strong>Mechanical strength<\/strong><br \/>\nAvoid SMT connectors that will be subject to frequent or heavy\nmechanical stress, as SMT solder joints have limited mechanical\ndurability. PTH solder joints perform much better in this regard.<\/p>\n<p><strong>Single technology<\/strong><br \/>\nAvoid components that require a specific production process, e.g., a\nsingle SMT component on a PTH board or vice versa, as this creates an\nadditional production step that is better avoided.<\/p>\n<p><strong>Pin-in-Paste (PIP) soldering<\/strong><br \/>\nIn pin-in-paste soldering, through-hole components are soldered using\nthe SMT reflow process. The components must be THR (Through-Hole Reflow)\ncompatible. PIP soldering is successful only up to a PCB thickness of\n1.6 mm, and the pin-to-hole ratio is important.<br \/>\n(see chapter on PIP soldering)<\/p>\n<p><strong>Number and variety of components per board<\/strong><br \/>\nWhile it is not always possible to control this, it is important to note\nthat some placement robots have a maximum capacity of around 10,000\ncomponents per board per side, and about 200 different types (= feeder\nslots on a placement robot).<br \/>\nFor manual through-hole assembly, smooth assembly is generally possible\nwith a maximum of about 20 different types. More than 20 types manually\nplaced tends to significantly increase the risk of errors.<\/p>\n<h1 class=\"dfm\" id=\"v-groove\">V-groove<\/h1>\n<p>A V-groove or scoring can be applied to PCBs with a thickness ranging\nfrom 0.8\u202fmm to 2.4\u202fmm.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 48%\" \/>\n<col style=\"width: 27%\" \/>\n<col style=\"width: 24%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th rowspan=\"4\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image10.png\"\nstyle=\"width:2.52083in;height:1.61458in\"\nalt=\"Afbeelding met diagram, lijn, tekst, Perceel Door AI gegenereerde inhoud is mogelijk onjuist.\" \/><\/th>\n<th><strong>Pcb thickness T1<\/strong><\/th>\n<th><strong>Restmaterial T2<\/strong><\/th>\n<\/tr>\n<tr>\n<th>0.8mm \u2013 1.0mm<\/th>\n<th>0.30mm \u00b1 0.01mm<\/th>\n<\/tr>\n<tr>\n<th>1.2mm \u2013 1.8mm<\/th>\n<th>0.40mm \u00b1 0.01mm<\/th>\n<\/tr>\n<tr>\n<th>2.0mm \u2013 2.4mm<\/th>\n<th>0.60mm \u00b1 0.01mm<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image11.png\"\nstyle=\"width:2.10417in;height:1.41667in\"\nalt=\"Afbeelding met diagram, schets, Plan, tekening Door AI gegenereerde inhoud is mogelijk onjuist.\" \/><\/td>\n<td colspan=\"2\"><p>A V-groove does not provide a perfectly precise\nseparation, so please take this into account when determining the\ndimensions of the enclosure. It is recommended to include an additional\nmargin of 0.1\u202fmm.<\/p>\n<p>Copper traces on both outer and inner layers should be kept at least\n0.4\u202fmm away from the board outline.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width:100%;\">\n<colgroup>\n<col style=\"width: 49%\" \/>\n<col style=\"width: 50%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image12.png\" \/><\/th>\n<th><p>Manually breaking a scoring line is not recommended, as it can\nintroduce stress on components and solder joints, potentially causing\ndamage or even breaking components.<\/p>\n<p>Depaneling is done using a rolling blade system, similar to a pizza\ncutter. It goes without saying that no components should extend over the\nscoring line, as they would be cut in two during the process.<\/p>\n<p>This blade system also requires some space, so it is advisable to\nplace taller components at a greater distance from the scoring\nline.<br \/>\nNext to this, you\u2019ll find a drawing showing the dimensions of the\ncutting blade.<\/p><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"contact-terminals-finish\">Contact terminals finish<\/h1>\n<p>The coating on contact terminals aims to provide a durable,\nlow-resistance contact connection. The coating protects the connector or\ncontact spring from forming metal oxides, as most metals are prone to\ncorrosion when exposed to oxygen, corrosive gases, temperature\nfluctuations, moisture, and salts.<\/p>\n<p>Gold and silver are popular choices due to their very low contact\nresistance and corrosion resistance. Nickel is a more economical option\nbut has slightly higher contact resistance. A non-noble tin coating can\nalso be used on contact connections, although the number of mating\ncycles is limited (&lt; 50).<\/p>\n<ul>\n<li><p>For analog signals, a gold finish is essential, as well as for\nconnectors used in industrial environments.<\/p><\/li>\n<li><p>Pure tin-coated contacts on data lines with a small pitch can\nsometimes experience whisker formation, which can be problematic. (see\nchapter on whisker formation)<\/p><\/li>\n<\/ul>\n<h1 class=\"dfm\" id=\"gold-embrittlement\">Gold Embrittlement<\/h1>\n<p>A solder joint with a relatively high gold content, typically above 3\nto 4%, will exhibit reduced strength. Both shear strength, impact\nstrength, and thermal cycling performance show adverse effects from gold\nin the solder joint.<\/p>\n<p>For gold-plated components in SMT, it is recommended to apply a\npre-tinning process. In some cases, adding extra solder volume may be\nsufficient to achieve a strong enough solder joint. It is best to avoid\ngold-plated SMT components if there are tin-plated or partially\ntin-plated alternatives available.<br \/>\nStandards J-STD-001 and IPC-HDBK-001 describe good workmanship practices\nregarding gold embrittlement.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 33%\" \/>\n<col style=\"width: 33%\" \/>\n<col style=\"width: 33%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image13.png\"\nstyle=\"width:1.76487in;height:1.62021in\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image14.png\"\nstyle=\"width:1.44247in;height:1.57575in\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image15.png\"\nstyle=\"width:1.57894in;height:1.55594in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">PLCC<\/td>\n<td style=\"text-align: center;\">connector<\/td>\n<td style=\"text-align: center;\">Partial tinned header<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The amount of gold plating on a component can be determined from the\nrelevant ASTM or MIL specifications. The thicker the gold layer, the\nmore robust the connector will be against wear and exposure to reactive\ngases\u2014but the less solderable it becomes.<br \/>\nIn the case of Class II finishes, the gold layer must be removed from\nthe solderable area as a preventive measure. (For Class I, it's\nrecommended to calculate the impact before proceeding.)<\/p>\n<table>\n<colgroup>\n<col style=\"width: 34%\" \/>\n<col style=\"width: 32%\" \/>\n<col style=\"width: 32%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><strong>Ag thickness<\/strong><\/th>\n<th style=\"text-align: center;\"><strong>ASTMB488<\/strong><\/th>\n<th style=\"text-align: center;\"><strong>MIL-G-45204<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">0.25um<\/td>\n<td style=\"text-align: center;\">Class 0.25<\/td>\n<td style=\"text-align: center;\">N\/A<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">0.75um<\/td>\n<td style=\"text-align: center;\">Class 0.75<\/td>\n<td style=\"text-align: center;\">Class 0<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">1.25um<\/td>\n<td style=\"text-align: center;\">Class 1.25<\/td>\n<td style=\"text-align: center;\">Class 1<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">2.50um<\/td>\n<td style=\"text-align: center;\">Class 2.50<\/td>\n<td style=\"text-align: center;\">Class 2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"silver-leads\">Silver leads <\/h1>\n<p>Silver leads, also known as components with a Silver (Ag)\/Platinum\n(Pt) coating, are prone to rapid oxidation. In particular, sulfur\ndioxide (SO\u2082) can severely affect the solderability of these\ncomponents.<br \/>\nAg\/Pt-coated components must be protected as much as possible from air\npollutants such as sulfur (S) and chlorine (Cl).<br \/>\nComponents with silver-coated leads are often vacuum-packed, similar to\nMSL-sensitive components. However, unlike MSL-sensitive parts, these\nmust <strong>not<\/strong> be dry-baked under any circumstances, and dry\nstorage in a moisture-free cabinet is <strong>not<\/strong> a suitable\nalternative to vacuum packaging.<\/p>\n<p>From a process perspective, there are additional constraints when\nworking with Ag\/Pt-finished components:<\/p>\n<ul>\n<li><p>The total soldering time (TAL) must be kept especially\nshort.<\/p><\/li>\n<li><p>The peak soldering temperature should be kept low.<\/p><\/li>\n<li><p>Preferably, a solder alloy containing sufficient silver should be\nused to counteract leaching, such as Sn62Pb36Ag2 or the lead-free SAC405\ninstead of SAC305.<\/p><\/li>\n<\/ul>\n<table style=\"width:100%;\">\n<colgroup>\n<col style=\"width: 99%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image16.png\"\nstyle=\"width:4.52104in;height:1.37597in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">Package label<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width:100%;\">\n<colgroup>\n<col style=\"width: 99%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image17.png\"\nstyle=\"width:2.52164in;height:1.83267in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">An Ag\/Pt connection showing\ncorrosion.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"different-smt-components\">Different SMT components<\/h1>\n<p>SMT components come in a wide variety of packages. Select the package\ntype thoughtfully to ensure that the technology generation on the board\nis as uniform as possible. Also consider the difficulty of inspection\nand repair when making your choice.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 50%\" \/>\n<col style=\"width: 49%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image18.png\"\nstyle=\"width:2.34375in;height:0.77328in\"\nalt=\"Afbeelding met schermopname, Rechthoek, ontwerp, pixel Automatisch gegenereerde beschrijving\" \/><\/th>\n<th><p><strong>Land grid array \/ No leads<\/strong><\/p>\n<p>Inspection is difficult. (RX)<\/p>\n<p>Repair is complex.<\/p><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image19.png\"\nstyle=\"width:2.375in;height:0.89164in\"\nalt=\"Afbeelding met Rechthoek, schermopname, lijn, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Pillar grid array<\/strong><\/p>\n<p>Inspection is simple. (RX)<\/p>\n<p>Repair is complex.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image20.png\"\nstyle=\"width:2.34375in;height:0.94401in\"\nalt=\"Afbeelding met schermopname, Rechthoek, ontwerp, clipart Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Ball grid array<\/strong><\/p>\n<p>Inspection is simple. (RX)<\/p>\n<p>Repair is relatively simple.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image21.png\"\nstyle=\"width:2.32292in;height:0.93732in\"\nalt=\"Afbeelding met Rechthoek, schermopname, visitekaartje, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Column grid array<\/strong><\/p>\n<p>Inspection is simple. (RX)<\/p>\n<p>Repair is complex.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image22.png\"\nstyle=\"width:2.34375in;height:0.84308in\"\nalt=\"Afbeelding met Rechthoek, schermopname, lijn, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Bump grid array<\/strong><\/p>\n<p>Inspection is simple. (RX)<\/p>\n<p>Repair is complex.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image23.png\"\nstyle=\"width:2.34375in;height:0.84774in\"\nalt=\"Afbeelding met schermopname, Rechthoek, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Flat lug terminal<\/strong><\/p>\n<p>Inspection can be difficult. (RX\/AOI)<\/p>\n<p>Repair can be complex.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image24.png\"\nstyle=\"width:1.97917in;height:0.99675in\"\nalt=\"Afbeelding met schermopname, Rechthoek, tekst, scherm Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>End cap terminal<\/strong><\/p>\n<p>Inspection is simple.(AOI)<\/p>\n<p>Repair is simple.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image25.png\"\nstyle=\"width:1.9375in;height:1.024in\"\nalt=\"Afbeelding met ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Outward-L lead<\/strong><\/p>\n<p>Inspection is simple. (AOI)<\/p>\n<p>Repair is simple.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image26.png\"\nstyle=\"width:1.91667in;height:1.01341in\"\nalt=\"Afbeelding met schermopname, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Gullwing lead<\/strong><\/p>\n<p>Inspection is simple. (AOI)<\/p>\n<p>Repair is simple.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image27.png\"\nstyle=\"width:1.92708in;height:1.06399in\"\nalt=\"Afbeelding met Rechthoek, schermopname, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>Inward-L lead<\/strong><\/p>\n<p>Inspection is simple. (AOI)<\/p>\n<p>Repair is simple.<\/p><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image28.png\"\nstyle=\"width:1.91667in;height:1.06234in\"\nalt=\"Afbeelding met schermopname, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p><strong>J-lead<\/strong><\/p>\n<p>Inspection is simple. (AOI)<\/p>\n<p>Repair can be difficult.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"batteries\">Batteries<\/h1>\n<p><strong>Storage of Large Quantities of Batteries<br \/>\n<\/strong>In volume assembly, large quantities of batteries are often\nrequired. Due to the real fire hazard they pose, many factories\nrightfully refuse to store them in the production hall or regular\nwarehouse. This creates a logistical challenge.<\/p>\n<p>For safety reasons, batteries are typically stored outside the main\nfactory building, in a fireproof area physically separated from the\nproduction facility. Lithium-ion batteries carry the additional risk of\nhigh energy density, are extremely difficult to extinguish in case of\nfire, and are best stored at temperatures between 5\u00b0C and 20\u00b0C.<\/p>\n<p>As a result, battery storage becomes an additional cost and a\nsignificant logistical challenge that should not be underestimated.<\/p>\n<p><strong>Overheating Due to Short Circuit<br \/>\n<\/strong>Connecting batteries to a PCBA before it has been properly\nfunctionally tested carries significant risk. The PCBA may still contain\nfaults\u2014such as a solder short\u2014that can cause the battery to overheat\nrapidly, potentially leading to fire or even explosion.<br \/>\nAlways opt for batteries with an internal overcurrent protection\ncircuit.<\/p>\n<p><strong>Puncturing of Batteries<br \/>\n<\/strong>A PCBA often contains sharp components, from PCB edges to\nthrough-hole leads or pin headers. It is not unthinkable that, during\nhandling, one of these sharp elements could puncture the battery. This\ncan lead to ignition or explosion.<br \/>\nPreferably, only connect the battery right before the PCBA is placed\ninto its final, secure enclosure.<\/p>\n<p><strong>Soldering of Coin Cell Batteries<br \/>\n<\/strong>Coin cells are sometimes soldered via the wave soldering\nprocess. In doing so, the battery becomes quite hot and is briefly\nshort-circuited\u2014both of which are unfavorable. While a coin cell can\ntechnically be short-circuited for up to 5 seconds, it is strongly\ndiscouraged.<br \/>\nA through-hole model with a slotted holder is preferred over a\nspot-welded version.<\/p>\n<p>See also the chapter on long-term storage.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 50%\" \/>\n<col style=\"width: 50%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image29.png\"\nstyle=\"width:1.88086in;height:1.26973in\"\nalt=\"Afbeelding met rond, overdekt, kunst Beschrijving automatisch gegenereerd met gemiddelde betrouwbaarheid\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image30.png\"\nstyle=\"width:1.78298in;height:1.25033in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">Solder ready model<\/td>\n<td style=\"text-align: center;\">Batteryholder<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"fiducial-markers\">Fiducial markers<\/h1>\n<p>Fiducial markers are reference points used by assembly and automated\ninspection equipment. These markers allow machines to accurately\ndetermine the exact position of the PCB, as well as calculate and\ncompensate for rotation, orientation, and board stretch.<br \/>\nIf fiducial markers are missing, assembly accuracy is significantly\nreduced, and in some cases, automated assembly may even become\nimpossible.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 100%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image31.png\"\nstyle=\"width:6.3in;height:4.51042in\"\nalt=\"Afbeelding met kaart, diagram, Plan, lijn Automatisch gegenereerde beschrijving\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p><strong>Fiducials on the PCB Panel<br \/>\n<\/strong>Three panel fiducials are placed along the edge of the panel.\nThese are used to determine the rotation and orientation of the\nboard.<br \/>\nIf additional machining operations are performed after depaneling,\ncircuit fiducial markers are also required.<br \/>\nComponent fiducial markers are recommended for ultra-fine pitch (UFP)\ncomponents on large boards.<\/p>\n<p><strong>Buildup<\/strong><\/p>\n<table>\n<colgroup>\n<col style=\"width: 52%\" \/>\n<col style=\"width: 47%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image32.png\"\nstyle=\"width:3.18137in;height:1.83333in\"\nalt=\"Afbeelding met diagram, tekst, lijn, cirkel Automatisch gegenereerde beschrijving\" \/><\/th>\n<th><p>A round pad with a diameter of 1.0 mm within a 2.0 mm solder mask\nclearance zone.<\/p>\n<p>Component fiducial markers may have a diameter of 0.50 mm.<\/p>\n<p>Avoid placing silkscreen text near fiducial markers, as this can\ninterfere with optical recognition.<\/p>\n<p><u>For white solder mask, increase the solder mask clearance zone\naround the fiducial to a 3 mm square<\/u><\/p><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p><strong>Long board function<\/strong><\/p>\n<p>Standard placement machines are equipped to handle boards up to a\nsize of 410 mm x 360 mm. Longer boards are possible, provided they are\nproduced on machines equipped with a long-board function. When using\nthis long-board function, the machine will load the board, partially\nassemble it, advance the board, and then continue assembling the\nremaining sections.<\/p>\n<p>In the example below of an 800 mm board, the machine will assemble it\nin three steps (with two advances).<br \/>\nIt is important to provide three sets of fiducial markers on the board\nto accurately determine its position after each board advance.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image33.png\"\nstyle=\"width:6.3in;height:2.69583in\"\nalt=\"Afbeelding met tekst, schermopname, Lettertype, lijn Automatisch gegenereerde beschrijving\" \/><\/p>\n<h1 class=\"dfm\" id=\"solderpaste-stencil-design\">Solderpaste stencil design<\/h1>\n<p>Solder paste can be applied by dispensing, jetting (contactless\npulsed dispensing), or screen printing. This section explains how to\napply stencil design without going into detail about very specific\nfootprints.<\/p>\n<p>To achieve a durable solder joint, we always aim to provide the\nmaximum possible amount of solder. More solder results in a mechanically\nstronger joint and a more flexible connection, which benefits\ndurability. Naturally, problems caused by excessive solder\u2014such as\nsolder wicking, solder bridges, and skewing\u2014should be avoided.<\/p>\n<p>Before starting, the stencil\u2019s Area Ratio (AR) must be determined. If\nthe stencil\u2019s AR is less than 0.66, the stencil will not function\nreliably. Preferably, the AR should be greater than 0.70.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image34.png\"\nstyle=\"width:4.43589in;height:2.4375in\" alt=\"Ratio calculation\" \/><\/p>\n<table>\n<colgroup>\n<col style=\"width: 37%\" \/>\n<col style=\"width: 62%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image35.png\"\nstyle=\"width:2.01966in;height:1.26719in\"\nalt=\"Afbeelding met Kleurrijkheid, schermopname, Graphics Automatisch gegenereerde beschrijving\" \/><\/th>\n<th><p>For square chip components, we reduce the stencil aperture by 40\nto 50 \u00b5m around the solder pad.<\/p>\n<p>This is done to prevent solder from spreading beyond the solder\nisland in the event of slight misalignment between the stencil and the\nPCB, which can cause mid-chip solder beads.<\/p>\n<p>0201 components with an open window design can be used without any\nreduction.<\/p><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image36.png\"\nstyle=\"width:2.0146in;height:2.15681in\"\nalt=\"Afbeelding met Kleurrijkheid, schermopname, Graphics Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p>SOT components (small outline with gull-wing leads) are cut\nwithout reduction between the stencil aperture and the solder pad.<\/p>\n<p>Due to the component\u2019s construction, it is insensitive to solder\nbeads, and the extra solder is beneficial.<\/p><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image37.png\"\nstyle=\"width:2.00373in;height:1.65343in\"\nalt=\"Afbeelding met Kleurrijkheid, Graphics, grafische vormgeving, groen Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p>For QFP components, we reduce the stencil aperture width by 40 \u00b5m\non both sides and the length (at the toe and heel) by 25 \u00b5m.<\/p>\n<p>The purpose of this reduction is to minimize the risk of solder\nbridges.<\/p><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image38.png\"\nstyle=\"width:2.01484in;height:1.45427in\"\nalt=\"Afbeelding met Graphics, grafische vormgeving, schermopname, Kleurrijkheid Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p>To avoid solder bridges, a general rule of thumb is to maintain a\ndistance between two apertures greater than twice the thickness of the\nstencil.<\/p>\n<p>If this ratio cannot be achieved, options include reducing the\nstencil thickness, further reducing the aperture sizes, or creatively\nrepositioning the apertures.<\/p><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image39.png\"\nstyle=\"width:2.06652in;height:1.74789in\"\nalt=\"Afbeelding met Graphics, Kleurrijkheid, grafische vormgeving, groen Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>In the case of a solder mask defined pattern, where the pads are\ndrawn wider than the spacing, we reduce the pad width to achieve EPEG\n(Equal Pad Equal Gap).<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image40.png\"\nstyle=\"width:2.08587in;height:1.78168in\"\nalt=\"Afbeelding met Graphics, Kleurrijkheid, schermopname, grafische vormgeving Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p>For QFN (no-lead) components, we reduce the exposed pad aperture\nto 60% of the original area when the area ratio (AR) of the leads is\ngreater than 0.66.<\/p>\n<p>This ensures uniform solder paste volume, reduces the risk of solder\nsplatter, and limits voiding.<\/p><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image41.png\"\nstyle=\"width:2.05965in;height:1.99873in\"\nalt=\"Afbeelding met Graphics, grafische vormgeving, Kleurrijkheid, schermopname Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p>For QFN (no-lead) components, we reduce the aperture width by 40\n\u00b5m (2 \u00d7 20 \u00b5m) and the length by 25 \u00b5m. The entire pattern is then\nshifted outward by 40 \u00b5m.<\/p>\n<p>This reduces the risk of solder bridges and promotes soldering with\nthe wettable flanks.<\/p><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image42.png\"\nstyle=\"width:2.03343in;height:1.20101in\"\nalt=\"Afbeelding met Rechthoek, plein, Kleurrijkheid, schermopname Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p>All apertures larger than 4 mm are symmetrically divided so that\neach individual aperture is smaller than 4 mm. The spacing (outgassing\nchannel) between apertures is at least 300 \u00b5m wide.<\/p>\n<p>This reduces the risk of the scoop effect caused by the squeegee and\nimproves outgassing.<\/p><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image43.png\"\nstyle=\"width:1.99655in;height:1.87941in\"\nalt=\"Afbeelding met Kleurrijkheid, plein, schermopname, Rechthoek Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>In designs with open vias, their use is preferably avoided.<br \/>\nSolder paste printing into vias is detrimental, as it tends to create\nexcessive air bubbles.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image44.png\"\nstyle=\"width:1.97687in;height:3.00429in\"\nalt=\"Afbeelding met Kleurrijkheid, groen, Rechthoek, plein Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><p>Power SOP components have a stand-off; in these components, the\nthermal pad is slightly elevated and does not make direct contact with\nthe pad.<\/p>\n<p>It is important that the applied solder paste thickness is at least\nequal to the height of this stand-off.<br \/>\nIf the stencil thickness is less than the component\u2019s stand-off height,\na step-up should be implemented at the thermal pad.<\/p><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image45.png\"\nstyle=\"width:1.9915in;height:1.79011in\"\nalt=\"Afbeelding met Symmetrie, zwart-wit Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image46.png\"\nstyle=\"width:1.97699in;height:1.80704in\"\nalt=\"Afbeelding met Graphics, schermopname, grafische vormgeving, clipart Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>For PICO size LGA components, we enlarge the smallest apertures to\nachieve a respectable area ratio (AR). This enlargement is done\noutwardly to prevent the risk of solder bridges.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image47.png\"\nstyle=\"width:1.94783in;height:1.92693in\"\nalt=\"Afbeelding met Kleurrijkheid, schermopname, groen, ontwerp Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>For BGAs with openings smaller than 400 \u00b5m, changing round apertures\nto square ones improves aperture fill quality.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image48.png\"\nstyle=\"width:1.92717in;height:1.26718in\"\nalt=\"Afbeelding met groen, Graphics, Kleurrijkheid, schermopname Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>For micro BGAs (YZP), we enlarge the apertures to match the diameter\nof the BGA balls.<br \/>\nIn the example on the left, the pad was only 150 \u00b5m, while the micro BGA\nsphere had a diameter of 230 \u00b5m. We increase the aperture size to 230 \u00b5m\nto achieve a more stable paste deposit.<br \/>\nDue to the 500 \u00b5m pitch, this does not pose a risk of solder\nbridges.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image49.png\"\nstyle=\"width:1.92054in;height:1.60045in\"\nalt=\"Afbeelding met cirkel, Kleurrijkheid, Graphics, groen Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>For mechanical spacers, we provide as much solder as possible to\ncreate a strong meniscus.<br \/>\nA crosshair design is necessary to avoid solder flowing into the\nvia.<\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image50.png\"\nstyle=\"width:1.92329in;height:1.53681in\"\nalt=\"Afbeelding met cirkel, zwart-wit, grille Automatisch gegenereerde beschrijving\" \/><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image51.png\"\nstyle=\"width:1.89998in;height:1.73934in\"\nalt=\"Afbeelding met Kleurrijkheid, patroon, Graphics, schermopname Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>For solder mask defined pads and copper defined pads, the solder\nvolume\/area should be equalized.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image52.png\"\nstyle=\"width:1.92265in;height:1.19975in\"\nalt=\"Afbeelding met schermopname, groen, Rechthoek, Kleurrijkheid Automatisch gegenereerde beschrijving\" \/><\/td>\n<td>Connectors and components subject to mechanical stress are provided\nwith as much solder as possible\u2014meaning no aperture reduction or\noversizing is applied.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td>Components with NIS contacts require at least 150 \u00b5m of solder\nthickness to achieve IPC-compliant fill.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td>Connectors and components subject to mechanical stress are provided\nwith as much solder as possible\u2014meaning no aperture reduction or\noversizing is applied.<\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image53.png\"\nstyle=\"width:2.11961in;height:1.8168in\" \/><\/td>\n<td>Areas where solder should not be applied must be removed from the\nstencil file, especially in cases of overlapping footprints\u2014such as the\nJTAG connector shown on the left.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image54.png\"\nstyle=\"width:2.12165in;height:2.13663in\" \/><\/td>\n<td><p>For a step-up (where the stencil thickness is locally increased),\nkeep the area as small as possible.<br \/>\nFor a step-down (where the stencil thickness is locally decreased), make\nthe area as large as possible around the component requiring the\nstep-down.<\/p>\n<p>Avoid changing the stencil thickness multiple times for the same\ncomponent.<\/p><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image55.png\"\nstyle=\"width:2.13017in;height:1.08363in\" \/><\/td>\n<td>Overlapping footprints, often used to accommodate two package\nvariants of the same component, should always have one of the two\nomitted.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image56.png\"\nstyle=\"width:2.1411in;height:1.3743in\" \/><\/td>\n<td>For pin-in-paste connections, we enlarge the apertures (oversize) to\nincrease the paste volume.<br \/>\nPaste can extend up to 4.0 mm onto the solder mask, maintaining a\nminimum clearance of 300 \u00b5m from other solder pads.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image57.png\"\nstyle=\"width:2.12605in;height:2.02591in\" \/><\/td>\n<td>When applying oversize apertures, as shown here for this metal stud,\nit is important to maintain a 300 \u00b5m clearance from other pads or\nfeatures, such as fiducials or milling lines.<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"special-pad-modifications\">Special pad modifications <\/h1>\n<p>In PCB locations with significant thermal imbalance, which can cause\nthe tombstone effect, applying a \"home plate design\" can provide\nimprovement.<br \/>\nThe inverted home plate design is a solution to counteract mid-chip\nsolder beads.<br \/>\nThe MELF home plate design improves wetting for MELF components and\nreduces skewing.<br \/>\nVariants include round or elliptical shapes.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image58.png\"\nstyle=\"width:6.15342in;height:2.65625in\"\nalt=\"How to Design PCB Stencil to Optimize Solder Paste Uses? : r\/AskElectronics\" \/><\/p>\n<h1 class=\"dfm\" id=\"layer-marking\">Layer marking<\/h1>\n<p>All the different layers in multilayer printed circuit boards should\npreferably be assigned a number, etched into the copper layer; starting\nwith the top layer as layer number 1. The bottom layer is then marked in\nmirrored text, making it readable from the bottom side.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 50%\" \/>\n<col style=\"width: 50%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image59.jpeg\"\nstyle=\"width:2.25in;height:1.6875in\" alt=\"P9280446\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image60.jpeg\"\nstyle=\"width:2.25in;height:1.6875in\" alt=\"P9280447\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p>The layer marking clearly indicates the number of layers present and\nhelps prevent misunderstandings during the layer stack-up process. For\nfield returns, the layer marking is also useful, as it allows repair\nrequirements to be identified even when the production documentation is\nunavailable.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 100%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image61.png\"\nstyle=\"width:6.16167in;height:2.46875in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"silkscreen-design\">Silkscreen design<\/h1>\n<p>If silkscreen is to be applied on the PCB to indicate the footprint,\nreference designator, or PIN1, ensure it is done in a uniform, clear,\nand organized manner. It is important that the silkscreen\u2014especially the\norientation marking\u2014remains visible after the component has been\nplaced.<\/p>\n<ul>\n<li><p>Silkscreen may discolor as a result of one of the thermal\nprocesses during production, depending on the type of ink used. Never\nuse silkscreen to make a PCB white. Use a white solder mask for this\npurpose instead. (see chapter <em>Permanent Solder Mask<\/em>)<\/p><\/li>\n<li><p>For PTH components, a component outline and reference designator\non the silkscreen are recommended.<\/p><\/li>\n<li><p>Avoid placing silkscreen in crowded areas, as this will only\nresult in a cluttered layout and potential misunderstandings.<\/p><\/li>\n<li><p>Do not place silkscreen near or as an indicator for fiducial\nmarkers; the white print can cause recognition issues with automated\nsystems.<\/p><\/li>\n<li><p>Avoid placing silkscreen near \u00b5-BGA, UFP, QFN, flip-chip\ncomponents, etc. In general, silkscreen should be avoided for fine-pitch\nSMT components.<\/p><\/li>\n<li><p>Include useful PCB information directly on the board to reduce\nthe need for additional labels later. (see chapter <em>Identification\nand Markings<\/em>)<\/p><\/li>\n<\/ul>\n<table style=\"width:92%;\">\n<colgroup>\n<col style=\"width: 46%\" \/>\n<col style=\"width: 45%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th colspan=\"2\" style=\"text-align: center;\"><strong>Silkscreen\nspecs<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Character height \/ width:<\/td>\n<td>1.00 tot 1.35mm \/ 0.60 tot 0.76mm<\/td>\n<\/tr>\n<tr>\n<td>Line thickness:<\/td>\n<td>0.15mm tot 0.20mm<\/td>\n<\/tr>\n<tr>\n<td>Clearance to solderable surfaces:<\/td>\n<td>0.50mm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Silk buildup<\/strong><\/p>\n<table>\n<colgroup>\n<col style=\"width: 33%\" \/>\n<col style=\"width: 33%\" \/>\n<col style=\"width: 33%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image62.png\" \/><\/th>\n<th style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image63.png\" \/><\/th>\n<th style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image64.png\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">SOT<\/td>\n<td style=\"text-align: center;\">Polarised condensator<\/td>\n<td style=\"text-align: center;\">Diode<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image65.png\" \/><\/td>\n<td style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image66.png\" \/><\/td>\n<td style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image67.png\" \/><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Resistor or non polarised\ncondensator<\/td>\n<td style=\"text-align: center;\">Elcap<\/td>\n<td style=\"text-align: center;\">BGA<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image68.png\" \/><\/td>\n<td style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image69.png\" \/><\/td>\n<td style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image70.png\" \/><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">QFN<\/td>\n<td style=\"text-align: center;\">DIL<\/td>\n<td style=\"text-align: center;\">QFP<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<colgroup>\n<col style=\"width: 50%\" \/>\n<col style=\"width: 49%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image71.png\" \/><\/th>\n<th style=\"text-align: center;\"><img\nsrc=\"https:\/\/page.be\/img_static\/e\/dfm\/image72.png\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">PTH resistor<\/td>\n<td style=\"text-align: center;\">PTH Diode<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><\/td>\n<td style=\"text-align: center;\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Silkscreen under component bodies is not acceptable.<\/p>\n<h1 class=\"dfm\" id=\"pcb-warpage-bow-twist-bending\">PCB Warpage (bow, twist,\nbending)<\/h1>\n<p><strong>PCBs should be flat. IPC-A-610 specifies a maximum allowable\nbow and twist of 0.75%.<\/strong><br \/>\nBoard warping typically occurs during production and can lead to issues\nsuch as: open connections on large components, shorts under BGAs, and\nmechanical stress on solder joints after assembly. In some cases, a\nboard may become so twisted that it becomes unprocessable in later\nproduction steps.<\/p>\n<p>The primary cause of warping is a mismatch in the coefficient of\nthermal expansion (CTE) between the laminate and the copper, usually due\nto an imbalance in copper distribution either within a single layer or\nbetween layers.<\/p>\n<p>Below is an example of a board that has remained permanently warped\nafter the soldering process.<\/p>\n<table style=\"width:100%;\">\n<colgroup>\n<col style=\"width: 99%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image73.png\"\nstyle=\"width:4.05968in;height:1.6884in\"\nalt=\"Afbeelding met elektronica, Elektronische engineering, stroomkring, Computeronderdeel Automatisch gegenereerde beschrijving\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p><strong>Warpage can be reduced by selecting a stiffer core laminate\nor by optimizing the copper distribution both within and between\nlayers.<\/strong><br \/>\nThis can be achieved by adding dummy copper areas or copper dots. In\nsome cases, the issue may also be caused by the fiber orientation of the\nlaminate.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 50%\" \/>\n<col style=\"width: 50%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image74.png\"\nstyle=\"width:2.42827in;height:2.04924in\"\nalt=\"Afbeelding met schermopname, groen, Rechthoek, diagram Automatisch gegenereerde beschrijving\" \/><\/th>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image75.png\"\nstyle=\"width:2.49356in;height:2.3191in\"\nalt=\"Afbeelding met schermopname, groen, Rechthoek, diagram Automatisch gegenereerde beschrijving\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"pcb-laminate-selection\">PCB laminate selection<\/h1>\n<p><strong>FR-4, or Flame Retardant Grade 4, is the most commonly used\nlaminate in service electronics.<\/strong><br \/>\nAlthough this fiberglass mat + epoxy resin laminate includes \"flame\nretardant\" in its name, it is not necessarily UL94V-0 compliant by\ndefault.<\/p>\n<p>Not all FR-4 materials are the same. In addition to dielectric\nspecifications, several process-related properties must also be\nconsidered:<\/p>\n<p><strong>TG (Glass Transition Temperature):<\/strong><\/p>\n<p>This is the temperature at which the laminate loses its mechanical\nstability. Depending on the type of laminate, TG can vary from around\n130\u202f\u00b0C to 190\u202f\u00b0C for high-TG materials.<br \/>\nThe difference between the TG and the maximum process temperature\ndetermines the CTE-induced stress on vias.<br \/>\nFor delicate PCBs with many or small-diameter vias, it is best to opt\nfor a high-TG laminate.<\/p>\n<p><strong>TD (Decomposition Temperature):<\/strong><\/p>\n<p>This is the temperature at which the PCB material begins to\nchemically decompose.<br \/>\nIn manufacturing, the TD must never be exceeded.<br \/>\nFortunately, the TD is typically above 300\u202f\u00b0C, while standard processing\ntemperatures are below 260\u202f\u00b0C.<br \/>\nHowever, during complex hot-air rework, local temperatures may\ntemporarily exceed this.<\/p>\n<p><strong>CTE (Coefficient of Thermal Expansion):<\/strong><\/p>\n<p>This defines the thermal expansion behavior of the laminate.<br \/>\nPCB datasheets usually list three CTE values:<\/p>\n<ul>\n<li><p><strong>CTE in the X-Y plane:<\/strong> Typically 10\u201320\nppm\/\u00b0C<\/p><\/li>\n<li><p><strong>CTE in the Z-axis (below TG):<\/strong> Around 50\nppm\/\u00b0C<\/p><\/li>\n<li><p><strong>CTE in the Z-axis (above TG):<\/strong> Around 250\nppm\/\u00b0C<\/p><\/li>\n<\/ul>\n<p>The CTE should be as close as possible to that of copper (16 ppm\/\u00b0C)\nto minimize stress between the laminate and copper during thermal\ncycles.<br \/>\nEven after production, mismatched CTE values between the PCB and stiff\ncomponent bodies can cause solder joint cracking.<br \/>\nSome components are available in both high-CTE and low-CTE versions for\nthis reason.<\/p>\n<p><strong>Moisture Absorption:<\/strong><\/p>\n<p>This is the amount of moisture the PCB can absorb, typically ranging\nfrom 0.05% to 0.20% by weight. Moisture uptake can affect the thermal\nand electrical properties of the laminate, such as its dielectric\nconstant.<br \/>\nIn production, laminates with higher moisture absorption are more\nsusceptible to blistering and delamination.<\/p>\n<h1 class=\"dfm\" id=\"hole-spacing-for-axial-components\">Hole spacing for axial\ncomponents<\/h1>\n<p>Provide a footprint that ensures leads do not need to be bent too\nclose to the component body, solder mask, or solder bends, as this can\ncause damage and lead to immediate rejection.<\/p>\n<p>Ensure that <strong>L1 \u2265 D1<\/strong>, with a minimum of 1 mm, to\nallow for automatic bending.<\/p>\n<p>The through-hole length (<strong>L2<\/strong>) of the THT lead on the\nsolder side is ideally 1 mm, with a minimum of 0.5 mm and a maximum of\n2.5 mm.<\/p>\n<p>The bending radius <strong>R1<\/strong> depends on the wire thickness\n(<strong>D1<\/strong>):<\/p>\n<ul>\n<li><p>For wire thickness up to 0.8 mm: <strong>R1 =\nD1<\/strong><\/p><\/li>\n<li><p>For wire thickness between 0.8 mm and 1.2 mm: <strong>R1 = 1.5 \u00d7\nD1<\/strong><\/p><\/li>\n<li><p>For wire thickness greater than 1.2 mm: <strong>R1 = 2 \u00d7\nD1<\/strong><\/p><\/li>\n<\/ul>\n<p>The hole spacing (<strong>L3<\/strong>) should satisfy:<br \/>\n<strong>L3 \u2265 Body + 2 mm + (3 \u00d7 D1)<\/strong><\/p>\n<table>\n<colgroup>\n<col style=\"width: 56%\" \/>\n<col style=\"width: 43%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image76.png\"\nstyle=\"width:3.43346in;height:2.66782in\"\nalt=\"Afbeelding met diagram, ontwerp, illustratie Automatisch gegenereerde beschrijving\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image77.png\"\nstyle=\"width:1.6063in;height:2.94267in\"\nalt=\"Afbeelding met schermopname, diagram, Kleurrijkheid, ontwerp Automatisch gegenereerde beschrijving\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"permanent-solder-mask\">Permanent solder mask<\/h1>\n<p><strong>Solder Mask Window<br \/>\n<\/strong>We opt for a copper-defined pattern. Only for \u00b5-BGA, WLP, and\nCSP packages is a solder mask-defined pattern sometimes recommended.\n(See chapter <em>CSP<\/em>)<br \/>\nUse a solder mask opening that is 100 \u00b5m to 200 \u00b5m larger than the SMT\nsolder pad (i.e., a clearance of 50 \u00b5m to 100 \u00b5m).<\/p>\n<p><strong>Solder Mask Color<br \/>\n<\/strong>The standard solder mask color is green; however, white, red,\nblue, yellow, or black are also possible. If there is no special reason,\ndo not deviate from the standard green color just for aesthetic\npurposes. Green is the customary color for PCB manufacturers, and other\ncolors usually require an additional production step.<\/p>\n<p>It is also better to stick with the standard green mask during\nsubsequent production stages.<\/p>\n<p>Sensors and camera exposures are calibrated for the green\nreflectivity. Automatic Optical Inspection (AOI) systems need to be\nrecalibrated for PCBs of other colors.<br \/>\nAdditionally, different solder masks can cause variations in soldering\neffects on the solder joint and may require different baking\nprocesses.<\/p>\n<p><strong>Glossy vs. Matte Solder Mask<br \/>\n<\/strong>A glossy solder mask delivers the cleanest result after a\nno-clean wave soldering process.<br \/>\nA matte solder mask is often the better choice if you plan to apply a\nconformal coating later without the need to roughen the mask. (See\nchapter <em>Applying Conformal Coating<\/em>)<br \/>\nAvoid using overly dark solder masks, as they can hide delamination\nissues.<\/p>\n<p><strong>Masking on Vias<br \/>\n<\/strong>Cover as many non-solderable areas, tracks, and vias as\npossible with solder mask.<br \/>\nThis prevents unwanted solder bridges or solder bleeding and makes the\nPCB easier to inspect.<\/p>\n<p><strong>Mask as Insulation<br \/>\n<\/strong>Solder mask should not be considered an insulating layer.<br \/>\nThe mask is not designed to function as a voltage insulator, and there\nis no guarantee or control that the coating is fully intact.<br \/>\nIn some areas, the mask thickness can be as thin as 5\u20137 \u00b5m.<\/p>\n<h1 class=\"dfm\" id=\"web-vs-window\">Web VS Window<\/h1>\n<p>The smallest solder mask track commonly applied within a standard PCB\nprice range is 100 \u00b5m with a 50 \u00b5m gap. For fine-pitch designs, however,\nthis 50 \u00b5m gap and 100 \u00b5m mask track may sometimes be insufficient. In\nsuch cases, the PCB manufacturer will typically recommend converting the\nstandard web design into a window design.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 50%\" \/>\n<col style=\"width: 50%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image78.jpeg\"\nstyle=\"width:2.224in;height:1.668in\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image79.jpeg\"\nstyle=\"width:2.22933in;height:1.672in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">Mask web design<\/td>\n<td style=\"text-align: center;\">Mask window design<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Do not do this without careful consideration, as it can lead to\nsolder shorts.<br \/>\nBelow are the layout guidelines for a successful window design.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 50%\" \/>\n<col style=\"width: 50%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image80.png\"\nstyle=\"width:2.23059in;height:2.13789in\" \/><\/th>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image81.png\"\nstyle=\"width:2.25006in;height:2.15557in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">Web pattern<\/td>\n<td style=\"text-align: center;\">Window pattern<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>In a web pattern, the pad width is half of the lead pitch\u2014for\nexample, for a 0.4 mm pitch, the pad width is 0.2 mm. When switching to\na window pattern, do not just remove the mask tracks; also increase the\npad width as shown in the sketch above.<br \/>\nThe pad width should then be 0.25 mm.<\/p>\n<h1 class=\"dfm\" id=\"soldermask-on-vias\">Soldermask on via\u2019s<\/h1>\n<p>There are several options for covering vias with or without solder\nmask:<\/p>\n<ul>\n<li><p><strong>Exposed via:<\/strong> The via is completely free of\nsolder mask.<\/p><\/li>\n<li><p><strong>Partial covered via:<\/strong> The via opening is left\nexposed, while the annular ring is partially covered with solder\nmask.<\/p><\/li>\n<li><p><strong>Via tenting:<\/strong> The via is fully covered with\nsolder mask; however, openings may be present, so it is not guaranteed\nto be completely sealed.<\/p><\/li>\n<li><p><strong>Plugged via:<\/strong> The via is fully blocked. (This is\nan additional manufacturing step.)<\/p><\/li>\n<\/ul>\n<table>\n<colgroup>\n<col style=\"width: 100%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image82.png\"\nstyle=\"width:6.26042in;height:1.34744in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p>From a reliability standpoint, partial covered vias are\npreferred.<\/p>\n<p>It is often mistakenly assumed that tented vias are fully sealed;\nhowever, this is not guaranteed and can cause issues such as conformal\ncoating leakage.<\/p>\n<h1 class=\"dfm\" id=\"x-outs\">X-outs<\/h1>\n<p><strong>X-outs, also known as cross-outs, are defective boards within\na panel that have been rejected by the PCB manufacturer.<\/strong><br \/>\nThe failed circuits are marked with an \"X\" by the manufacturer.<\/p>\n<p>For the assembly facility, these X-outs are problematic because they\nmust not be assembled and therefore need to be excluded from all\ninspection, testing, and assembly robots.<\/p>\n<p>Preferably, we order PCBs without X-outs. This may involve additional\ncosts from the PCB manufacturer. Boards with X-outs slow down the\nassembly process and will result in higher costs at the assembly\nfacility.<\/p>\n<table style=\"width:100%;\">\n<colgroup>\n<col style=\"width: 99%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image83.png\"\nstyle=\"width:3.57385in;height:2.15093in\"\nalt=\"Afbeelding met plein, groen, Rechthoek, lijn Automatisch gegenereerde beschrijving\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p>If PCBs with X-outs are ordered, ensure BAD markers are provided\n(recognition points for robots to identify boards that must not be\nassembled).<\/p>\n<h1 class=\"dfm\" id=\"high-current-design\">High current design<\/h1>\n<p>We are frequently asked how large a via should be to ensure it can\ncarry the same current as the trace. A simple rule of thumb is the\nfollowing:<\/p>\n<p><strong>The via diameter should be one-third of the trace\nwidth<\/strong>, assuming the via wall thickness is half the copper\nthickness. For example, with 35\u202f\u00b5m copper, the via wall would be\napproximately 17\u202f\u00b5m thick.<\/p>\n<p>However, because via plating thickness is not always consistent\u2014and\nin some cases may be thinner than expected\u2014we strongly recommend placing\n<strong>multiple vias<\/strong> and maintaining a generous safety\nmargin.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 48%\" \/>\n<col style=\"width: 51%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image84.jpeg\"\nstyle=\"width:2.625in;height:1.9664in\"\nalt=\"http:\/\/www.printed.cz\/assets\/photos\/fullsize\/_kontrola-a_0.jpg\" \/><\/th>\n<th style=\"text-align: left;\"><p>If the PCB undergoes a wave soldering\nprocess, open vias will fill with solder, which can increase their\ncurrent-carrying capacity. However, if you are working close to the\nlimits and relying on solder filling, it is important to inform the\nproduction team about this requirement.<\/p>\n<p>There are plenty of online calculators available to determine how\nmuch current a trace can carry. It is crucial to consider cooling in\nthese calculations. Ensure that traces carrying high currents are placed\non the outer layers of the PCB, as this allows the trace to dissipate\nheat more effectively.<\/p><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p><strong>Thermal relief design for high current<\/strong><\/p>\n<table>\n<colgroup>\n<col style=\"width: 100%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image85.png\"\nstyle=\"width:3.25in;height:1.91481in\"\nalt=\"Afbeelding met geel, cirkel Door AI gegenereerde inhoud is mogelijk onjuist.\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p>For very high currents that need to be conducted from the top side to\nthe bottom side of the PCB, it is recommended to duplicate as many\nsolder pins as possible. In the above sketch, you can see that three\npins of a connector have been duplicated. However, a thermal relief\ndesign must be applied to ensure smooth solder flow during the wave\nsoldering process.<\/p>\n<p>Thermal relief tracks limit current flow; to prevent these tracks\nfrom acting like fuses\u2014even though there are 12 in this example above\u2014we\nplace enough vias around the solder pins. These vias help distribute the\ncurrent, thereby relieving the thermal relief tracks.<\/p>\n<h1 class=\"dfm\" id=\"bendable-pcbs\">Bendable PCB\u2019s<\/h1>\n<p>As solutions for flexible substrates, there are Flexrigid, Full Flex,\nFR4 Semi-Flex, and Polyester PCBs.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 45%\" \/>\n<col style=\"width: 54%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image86.jpeg\"\nstyle=\"width:1.85417in;height:1.48333in\"\nalt=\"http:\/\/eu.finetech.de\/typo3temp\/pics\/flex-1-circuit-1_typo3_eb31fa9b8c.jpg\" \/><\/th>\n<th>In a full flex PCB, components are also mounted on a flexible\npolyimide section.<br \/>\nUsually, a stiffener is applied in that area to provide local\nrigidity.<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image87.png\"\nstyle=\"width:1.44792in;height:1.46865in\"\nalt=\"http:\/\/techdocs.altium.com\/sites\/default\/files\/wiki_attachments\/231350\/RigidFlex3.png\" \/><\/td>\n<td>In a flex-rigid PCB, the components are mounted on a rigid section\nof the board, while the inner layers extend to form the flexible\nparts.<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image88.jpeg\"\nstyle=\"width:2in;height:0.88817in\"\nalt=\"http:\/\/www.leiton.de\/img\/common\/seiten-sondertechnologien\/semi-flex-2.jpg\" \/><\/td>\n<td>A semi-flex FR4 PCB is a standard PCB where a portion is selectively\nthinned by milling, resulting in a remaining section thin enough to be\nbendable, typically around 100 \u00b5m thick.<br \/>\nThis is a simple solution suitable for electronics that need to be bent\nonly once.<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image89.jpeg\"\nstyle=\"width:1.65625in;height:1.24249in\"\nalt=\"X:\\Produktie\\ISO\\6.2.2 Bekwaamheid training en bewustzijn\\Q-LED project\\Testen polyester pcb\\IMGP0586.JPG\" \/><\/td>\n<td>Metal Jet Polyester PCB is a low-cost solution for single-layer\nflexible substrates, albeit with several limitations.<br \/>\nThe copper thickness is limited to 3 to 4 \u00b5m, and the polyester material\ncan only withstand temperatures up to 150\u00b0C, which necessitates the use\nof low-temperature solder.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>For full flex PCBs, tooling is required or careful design using rigid\nstiffener bezels.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image90.jpeg\"\nstyle=\"width:2.59375in;height:1.94531in\"\nalt=\"Afbeelding met Rechthoek, overdekt, kunst Automatisch gegenereerde beschrijving\" \/><\/p>\n<h1 class=\"dfm\" id=\"tin-whiskers\">Tin-whiskers <\/h1>\n<p>Tin whiskers form due to internal material stress combined with the\ngrowth of the Cu\u2086Sn\u2085 intermetallic compound (IMC) layer.<br \/>\nThis internal stress initiates the growth of single-crystal whiskers\nfrom the tin layer.<br \/>\nThese whiskers are typically about 1 \u00b5m in diameter and, in some cases,\ncan grow up to 10 mm in length.<\/p>\n<table style=\"width:100%;\">\n<colgroup>\n<col style=\"width: 99%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image91.png\"\nstyle=\"width:3.15202in;height:2.37337in\" \/><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<\/tbody>\n<\/table>\n<p>Tin whiskers most commonly occur on pure tin-coated components.<br \/>\nA similar phenomenon is observed with zinc, known as zinc whiskers.<\/p>\n<p>Do not confuse whiskers with dendrite formation. Dendrites result\nfrom the migration of metal crystals caused by ionic contamination,\nmoisture, and electrical stress.<\/p>\n<p>Because the exact mechanism by which these conductive \u201cantennas\u201d grow\nis still not fully understood, and whisker growth can sometimes start\nimmediately but often takes years to develop, tin whiskers pose a real\nrisk to electronic products.<br \/>\nData lines can be short-circuited, and there are documented cases where\nwhiskers have withstood currents of up to several tens of milliamps\nbefore vaporizing.<\/p>\n<h1 class=\"dfm\" id=\"waterproof\">Waterproof<\/h1>\n<p>After a negative experience, the question often arises: how to make\nelectronics water-resistant? Electronics used in outdoor applications\ncan become so degraded after just a few months that malfunctions occur.\nA moisture-tight enclosure is a must.<\/p>\n<p><strong>IP68 Enclosure<\/strong><br \/>\nIP68 means: \"dust-tight and waterproof, device remains usable under\nmanufacturer-specified conditions.\"<br \/>\nThis says little about moisture-tightness over weeks, months, or years;\nit only guarantees that no water enters the device for a certain\nperiod.<br \/>\nWater vapor molecules (H\u2082O gas) are about 400 times smaller than water\ndroplets. While an enclosure might be waterproof for half an hour, it is\nnot necessarily vapor-tight for long durations.<\/p>\n<p><strong>How to Achieve a Water-Tight Enclosure<\/strong><br \/>\nStart with a good, sturdy IP68 enclosure. Metal is preferred over\nplastic because most plastics are hygroscopic.<br \/>\nSelect an enclosure with enough screws or clamps so the sealing ring is\nfirmly compressed. For a rectangular box, choose one where the screws\nare evenly spaced for uniform pressure on the seal.<br \/>\nEnclosures with clamps have the advantage of simpler O-ring designs and\na predetermined clamping force. Opt for enclosures with mounting holes\noutside the chamber or with a mounting bracket.<\/p>\n<p><strong>Cable Glands and Cable Entry<\/strong><br \/>\nEnclosures with molded-in cable glands are preferred, as this saves a\nseal and prevents glands from loosening.<br \/>\nIdeally, route all cables through the bottom of the enclosure.<\/p>\n<p><strong>Reducing Salts on the PCB<\/strong><br \/>\nSalts are a major cause of corrosion; combined with moisture and bias\nvoltage, salts initiate electromigration.<br \/>\nRemoving salts from the circuitry is a crucial step. This requires\nwashing the electronics.<\/p>\n<p><strong>Potting and Conformal Coating<\/strong><br \/>\nApplying conformal coating will not make your circuit waterproof but\nserves as a good corrosion inhibitor and protects against condensation.\nA coating will definitely help extend your electronics\u2019 lifespan.<br \/>\nPotting the electronics, however, does provide waterproofing. Components\nwith screw connections or moving parts usually cannot be potted. Partial\npotting is often a good alternative.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image92.jpeg\" \/><\/p>\n<h1 class=\"dfm\" id=\"long-time-storage\">Long time storage<\/h1>\n<p><strong>Long-Term Storage Considerations<\/strong><\/p>\n<p>By long-term storage, we mainly mean a duration exceeding the\nmanufacturer\u2019s guaranteed shelf life. Components, PCBs, or complete\nassemblies often need to be stored for extended periods. This can have\nvarious reasons\u2014for example, due to MOQ (minimum order quantities),\nsurplus parts are kept in stock. Bare PCBs or custom parts are often\npurchased in larger batches to reduce costs and processed over time.\nAssemblies may also be stored waiting for installation. Additionally,\nparts may need to be stocked for up to 15 years to guarantee\navailability for the aftermarket.<\/p>\n<p><strong>Shock Resistance<\/strong><br \/>\nParts stored for long periods will likely be moved multiple times. Use\nrobust, shock-resistant packaging.<\/p>\n<p><strong>ESD Protection<\/strong><br \/>\nESD-safe packaging prevents buildup of static charge that can damage\nsensitive semiconductors.<br \/>\nAvoid using foam and plastic materials that generate static, as well as\nprinted paper and packaging tape, which can induce high static charges.\nDissipative materials with antistatic additives (such as pink poly bags)\ngenerally guarantee antistatic properties for only about six months.<\/p>\n<p><strong>Contamination<\/strong><br \/>\nInitially, contamination means dust, which can originate from cardboard\nboxes or packaging materials themselves. Dust can cause shorts or damage\nopen chip sensors and similar components.<br \/>\nHandling and repeated touching of parts can deposit oils, salts, and\nother residues that cause long-term damage.<br \/>\nTake precautions against contaminated or aggressive air, such as oil\nvapors.<\/p>\n<p><strong>Moisture Protection<\/strong><br \/>\nParts, especially plastics, absorb moisture and can suffer moisture\ndamage during soldering, notably MSL-sensitive components and PCBs.<\/p>\n<p><strong>Corrosion<\/strong><br \/>\nMetals can corrode during long storage due to exposure to aggressive\nair, moisture, or the presence of acids and salts (e.g., salty air,\nammonia, chlorine, sulfur, or vapors from acidic silicones).<br \/>\nAssemblies should be stored in airtight packaging with desiccants and\/or\nanti-tarnish strips.<br \/>\nFor very long storage, assemblies should be cleaned of flux\nresidues.<\/p>\n<p><strong>Condensation Resistance<\/strong><br \/>\nComponents can be sensitive to condensing air, especially pre-installed\nelectronics and nearly hermetically sealed parts. Relays can also be\nsusceptible to condensation damage.<\/p>\n<p><strong>Solderability<\/strong><br \/>\nThe solderability of nickel-plated parts, OSP or ENIG PCBs, brass solder\ncontacts, etc., can degrade and complicate later processing.<\/p>\n<p><strong>Diffusion<\/strong><br \/>\nIntermetallic growth can impair solderability. Keep this in mind\nregarding the shelf life of tin-plated items like HASL PCBs and\ntin-plated leads.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image93.jpeg\"\nstyle=\"width:2.89583in;height:1.76622in\"\nalt=\"Afbeelding met groen, stroomkring Automatisch gegenereerde beschrijving\" \/><\/p>\n<p><strong>Tin Whiskers<br \/>\n<\/strong>Pure tin components can exhibit whisker growth. Tin whiskers\ncan cause solder shorts on data lines; these are mainly chemically\ntin-plated parts.<\/p>\n<p><strong>Tin Pest<br \/>\n<\/strong>Tin stored at low temperatures can degrade itself. The tin\nstructure changes from beta-tin to alpha-tin.<\/p>\n<p><strong>Plastic Embrittlement<br \/>\n<\/strong>Plastics age and become brittle due to UV exposure, the action\nof gases, and drying out. Prolonged storage at elevated temperatures can\nalso affect the durability of plastics, primarily causing a loss of\nflexibility.<\/p>\n<p><strong>Aging of Electrolytic Capacitors<br \/>\n<\/strong>The quality of the electrolyte and the storage temperature are\nthe main factors determining how long a capacitor can be stored before\nit loses its specified characteristics.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image94.jpeg\"\nstyle=\"width:3.10417in;height:2.00529in\"\nalt=\"Afbeeldingsresultaat voor ageing of capacitors graph\" \/><\/p>\n<p><strong>Energy loss<\/strong><\/p>\n<p>Batteries must not lose their energy. Ensure there is no standby\ncurrent drain during storage, and avoid conductive packaging that can\ndischarge the battery. Lithium batteries have the longest lifespan,\nexceeding 15 years..<\/p>\n<h1 class=\"dfm\" id=\"ip-protection-intellectual-property\">IP protection (intellectual\nproperty)<\/h1>\n<p><strong>Protecting your design against intellectual theft, cheap\ncopies, or making it completely tamper\u2011proof is not straightforward.\nConversely, reverse engineering is also not easy \u2014 once you make it\ndifficult for a pirate, there is a good chance they will fail to copy\nyour design.<\/strong><\/p>\n<p>Intellectual theft often occurs when competitors try to extract your\nknow\u2011how to integrate it into their own designs.<\/p>\n<p>Making a product tamper\u2011proof (or tamper\u2011evident) is aimed at\npreventing unauthorized opening of the device, which could affect\noperation or void the warranty.<\/p>\n<p>Counterfeiters may reproduce an entire product to sell a cheaper\nversion, sometimes using identical housings and markings to mislead\nconsumers.<\/p>\n<p><strong>Discouraging piracy<\/strong><\/p>\n<p>Sell your product at a fair price through a network that provides\ngood service. This is the most obvious solution \u2014 \u201cif there is no\ntreasure to be gained, there is no thief.\u201d<\/p>\n<p>Protect yourself legally with patents and copyright. In any case,\ninclude \u201cPatent pending\u201d and copyright markings.<\/p>\n<p>Apply a recognizable logo or product name so customers do not\ninadvertently fall for look\u2011alike items.<\/p>\n<p>Continuously improve your design so copycats are always playing\ncatch\u2011up \u2014 time is their greatest enemy.<\/p>\n<p><strong>Secure your production chain<\/strong><\/p>\n<p>Use robust NDA contracts and work with trustworthy partners. Pure EMS\ncompanies usually have no interest in stealing your ideas; an EMS that\nalso performs R&amp;D in the same sector is a higher risk.<\/p>\n<p>Consider internal confidentiality too \u2014 dismissed employees sometimes\ntake more know\u2011how than they are entitled to.<\/p>\n<p>Don\u2019t outsource the entire work package to a single subcontractor.\nYou can split tasks, for example:<\/p>\n<ul>\n<li><p>Order the PCB yourself from the board house.<\/p><\/li>\n<li><p>Purchase delicate ICs yourself and re\u2011code\/program them; if\nprogramming services are needed, outsource that to a different party\nthan the EMS.<\/p><\/li>\n<li><p>Store design data securely and preferably split across multiple\nlocations \u2014 piracy often starts with stolen CAD data via\nhacking.<\/p><\/li>\n<\/ul>\n<p><strong>Protect against tampering<\/strong><\/p>\n<ul>\n<li><p>Use tamper\u2011proof screws, hidden screws, and tamper\u2011evident\nlabels.<\/p><\/li>\n<li><p>Consider clever countermeasures (e.g., circuitry that erases chip\nmemory or disables sensitive components when the enclosure is opened\nimproperly).<\/p><\/li>\n<\/ul>\n<p><strong>Make reverse engineering difficult<\/strong><\/p>\n<ul>\n<li><p>Remove textual markings from ICs \u2014 this already makes reverse\nengineering harder.<\/p><\/li>\n<li><p>Apply a hard\u2011to\u2011remove coating over dense chip areas. This won\u2019t\nstop a professional pirate but will deter hobbyists.<\/p><\/li>\n<li><p>Use passive components without value markings.<\/p><\/li>\n<li><p>Add false traces in inner layers and use copper pours to make\nX\u2011ray copying very difficult.<\/p><\/li>\n<li><p>Use custom ASICs \u2014 these make reverse engineering virtually\nimpossible.<\/p><\/li>\n<\/ul>\n<blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image95.jpeg\"\nstyle=\"width:3.17708in;height:2.33609in\"\nalt=\"C:\\Users\\bartl\\AppData\\Local\\Microsoft\\Windows\\Temporary Internet Files\\Content.MSO\\CCF6771A.JPG\" \/><\/p>\n<\/blockquote>\n<h1 class=\"dfm\" id=\"component-supply\">Component supply<\/h1>\n<p>Components must be supplied in production-friendly packaging to\nenable efficient, reliable, and fast feeding into the machines.<\/p>\n<p>Even in the case of prototyping\u2014where full packaging quantities are\npreferably avoided\u2014machine-friendly packaging is still preferred. SMT\ncomponents are often small, fragile, and no longer easy to place\nmanually. The absence of standardized packaging can result in components\nbeing placed incorrectly.<\/p>\n<table>\n<colgroup>\n<col style=\"width: 47%\" \/>\n<col style=\"width: 52%\" \/>\n<\/colgroup>\n<tbody>\n<tr>\n<td style=\"text-align: center;\"><strong>Componenttypes<\/strong><\/td>\n<td style=\"text-align: center;\"><strong>Voorkeur\nverpakking<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Chip components (square chip &amp;\nmelf)<\/td>\n<td style=\"text-align: center;\">Tape on reel<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">SOP (small outline packages)<\/td>\n<td style=\"text-align: center;\">Tape on reel<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">QFP<\/td>\n<td style=\"text-align: center;\">Tray<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Small size BGA &amp; QFN up to\n20x20mm<\/td>\n<td style=\"text-align: center;\">Tape on reel<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Larger BGA's<\/td>\n<td style=\"text-align: center;\">Tray<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Shielding<\/td>\n<td style=\"text-align: center;\">Tray of Tube<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">SMT Connectors<\/td>\n<td style=\"text-align: center;\">Tape on reel up to 44mm, take info for\nlarger connectors<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"vocs\">VOC\u2019s<\/h1>\n<p><strong>\u201cVolatile Organic Compounds\u201d (VOCs) are often discussed in\nthe context of environmental and emission regulations, but they can also\ncause issues with LEDs.<\/strong><\/p>\n<p>This is especially relevant in weatherproof, hermetically sealed\nelectronic assemblies, where VOCs can negatively impact the lifespan and\nlight output of LEDs. VOCs migrate into the silicone lens of the LED and\ncondense on the LED die. LEDs that emit white or blue light are\nparticularly sensitive to this.<\/p>\n<p>VOCs are commonly used chemical compounds found in solder fluxes,\nadhesives, coatings, O-rings and seals, potting compounds, etc. These\nmaterials are frequently used in electronics and can release VOCs\nthrough outgassing or when heated. In an enclosed environment, such VOCs\ncan adversely affect the performance of nearby LEDs.<\/p>\n<p><strong>VOC-related LED issues can be recognized by a cloudy lens or\na brownish deposit on the die.<\/strong> In most cases, this results in a\nnoticeable drop in light output. In some instances, the LED may begin to\nflicker or fail completely.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/page.be\/img_static\/e\/dfm\/image96.png\"\nstyle=\"width:2.86458in;height:1.36458in\"\nalt=\"Afbeelding met cirkel, licht Automatisch gegenereerde beschrijving\" \/><\/p>\n<h1 class=\"dfm\" id=\"ultrasonic-welding-of-plastic-housings\">Ultrasonic Welding of\nPlastic Housings<\/h1>\n<p>Ultrasonic welding is a widely used technique for joining plastic\nparts\u2014such as enclosures or housings\u2014quickly and securely without the\nuse of adhesives, screws, or other fasteners. It is commonly applied in\nindustries like electronics, automotive, medical devices, and consumer\nproducts to achieve a strong watertight seal.<\/p>\n<hr \/>\n<p><strong>Advantages of Ultrasonic Welding<\/strong><\/p>\n<ul>\n<li><p><strong>Fast<\/strong>: Welding takes less than a second in most\ncases.<\/p><\/li>\n<li><p><strong>Strong and reliable<\/strong>: The joint is as strong as\nthe base material.<\/p><\/li>\n<li><p><strong>No extra materials needed<\/strong>: No glue, screws, or\nsolvents required.<\/p><\/li>\n<li><p><strong>Easily automated<\/strong>: Suitable for high-volume\nproduction.<\/p><\/li>\n<li><p><strong>Environmentally friendly<\/strong>: No emissions or waste\nfrom adhesives or solvents.<\/p><\/li>\n<\/ul>\n<hr \/>\n<p><strong>Limitations<\/strong><\/p>\n<ul>\n<li><p><strong>Material compatibility<\/strong>: Only thermoplastics can\nbe used. Ideally, both parts should be made of the same\nmaterial.<\/p><\/li>\n<li><p><strong>Design constraints<\/strong>: Parts must be specifically\ndesigned for ultrasonic welding (e.g. with energy directors).<\/p><\/li>\n<li><p><strong>Size limitations<\/strong>: Large parts are harder to weld\ndue to vibration dispersion.<\/p><\/li>\n<li><p><strong>Aesthetic impact<\/strong>: Weld lines or minor surface\ndeformation may occur.<\/p><\/li>\n<\/ul>\n<hr \/>\n<p><strong>Common Plastics Used in Ultrasonic Welding<\/strong><\/p>\n<ul>\n<li><p>ABS (Acrylonitrile Butadiene Styrene)<\/p><\/li>\n<li><p>Polypropylene (PP)<\/p><\/li>\n<li><p>Polycarbonate (PC)<\/p><\/li>\n<li><p>Polystyrene (PS)<\/p><\/li>\n<li><p>Nylon (PA)<\/p><\/li>\n<li><p>PVC (in some cases)<\/p><\/li>\n<\/ul>\n<p>Different plastics can sometimes be welded together, but only if they\nare thermally and chemically compatible.<\/p>\n<hr \/>\n<p><strong>Typical Applications for Plastic Enclosures<\/strong><\/p>\n<ul>\n<li><p>Electronic housings (e.g. remote controls, sensors)<\/p><\/li>\n<li><p>Medical devices (e.g. disposables)<\/p><\/li>\n<li><p>Automotive components (e.g. dashboard sensors)<\/p><\/li>\n<li><p>Consumer products (e.g. chargers, battery cases)<\/p><\/li>\n<li><p>Portable devices (e.g. Bluetooth speakers)<\/p><\/li>\n<\/ul>\n<hr \/>\n<p><strong>Design Tips for Ultrasonic Welding<\/strong><\/p>\n<p>When designing a product or enclosure for ultrasonic welding,\nconsider:<\/p>\n<ul>\n<li><p>Weld geometry (e.g. small triangular ribs called <strong>energy\ndirectors<\/strong>)<\/p><\/li>\n<li><p>Alignment features (e.g. guide pins, snap fits)<\/p><\/li>\n<li><p>Sonotrode access (the weld area must be reachable by the\nhorn)<\/p><\/li>\n<\/ul>\n<hr \/>\n<p><strong>Main Risks<\/strong><\/p>\n<p><strong>1. Mechanical damage from vibrations<\/strong><\/p>\n<ul>\n<li><p>Vibrations can travel through the plastic into internal PCBs and\ncomponents.<\/p><\/li>\n<li><p>This may result in:<\/p>\n<ul>\n<li><p><strong>Cracked solder joints<\/strong><\/p><\/li>\n<li><p><strong>Broken IC bond wires<\/strong><\/p><\/li>\n<li><p><strong>Fractured ceramic capacitors and Kristal\ncomponents<\/strong><\/p><\/li>\n<li><p><strong>Loose connectors or internal cables<\/strong><\/p><\/li>\n<\/ul><\/li>\n<\/ul>\n<p><strong>2. Overheating from localized heat<\/strong><\/p>\n<ul>\n<li><p>The melting process at the weld interface can generate heat that\nspreads to nearby parts.<\/p><\/li>\n<li><p>Consequences may include:<\/p>\n<ul>\n<li><p><strong>Thermal degradation<\/strong> of temperature-sensitive\ncomponents<\/p><\/li>\n<li><p><strong>Plastic deformation<\/strong> of housings or connector\nparts<\/p><\/li>\n<li><p><strong>PCB delamination<\/strong> in multilayer boards<\/p><\/li>\n<\/ul><\/li>\n<\/ul>\n<p><strong>3. Damage to sensors and MEMS devices<\/strong><\/p>\n<ul>\n<li><p>Ultrasonic vibrations are especially harmful to:<\/p>\n<ul>\n<li><p><strong>MEMS sensors<\/strong> (e.g. accelerometers,\ngyros)<\/p><\/li>\n<li><p><strong>Microphones and audio components<\/strong><\/p><\/li>\n<li><p><strong>Components with moving parts<\/strong> (e.g. hard\ndrives)<\/p><\/li>\n<\/ul><\/li>\n<li><p>These may be permanently damaged or provide incorrect\nmeasurements.<\/p><\/li>\n<\/ul>\n<p><strong>4. Loss of calibration<\/strong><\/p>\n<ul>\n<li><p>Precise sensors or measuring devices can become\n<strong>miscalibrated<\/strong> due to micro-shifts or internal\nstress.<\/p><\/li>\n<\/ul>\n<hr \/>\n<p><strong>Best Practices to Minimize Risk<\/strong><\/p>\n<table>\n<colgroup>\n<col style=\"width: 37%\" \/>\n<col style=\"width: 62%\" \/>\n<\/colgroup>\n<thead>\n<tr>\n<th><strong>Measure<\/strong><\/th>\n<th><strong>Description<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Keep sensitive parts away<\/strong><\/td>\n<td>Place components far from the weld area.<\/td>\n<\/tr>\n<tr>\n<td><strong>Use vibration dampers<\/strong><\/td>\n<td>Introduce <strong>damping materials<\/strong> or structural isolation\nbetween housing and PCB.<\/td>\n<\/tr>\n<tr>\n<td><strong>Secure fixture design<\/strong><\/td>\n<td>Use a <strong>custom fixture<\/strong> to minimize vibration transfer\nto the electronics.<\/td>\n<\/tr>\n<tr>\n<td><strong>Use low-energy settings<\/strong><\/td>\n<td>Reduce welding time, pressure, and amplitude.<\/td>\n<\/tr>\n<tr>\n<td><strong>Isolate PCB mounting<\/strong><\/td>\n<td>Mount PCBs using <strong>rubber grommets<\/strong> or floating\nsupports.<\/td>\n<\/tr>\n<tr>\n<td><strong>Conduct thorough testing<\/strong><\/td>\n<td>Test prototypes with stress, X-ray, or functional checks.<\/td>\n<\/tr>\n<tr>\n<td><strong>Consider alternatives<\/strong><\/td>\n<td>If ultrasonic welding is too risky, use <strong>other bonding\nsystems<\/strong> instead.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1 class=\"dfm\" id=\"abbreviations\">Abbreviations<\/h1>\n<blockquote>\n<p>AOI: Automatic optical inspection.<\/p>\n<p>BGA: Ball grid array.<\/p>\n<p>CSP: Chip scale package.<\/p>\n<p>EMS: Electronic manufacturing supplier.<\/p>\n<p>ENIG: Electroless Nickel Immersion Gold.<\/p>\n<p>EOL: End of life.<\/p>\n<p>EOS: Electrostatic overstress.<\/p>\n<p>EPA: Electrostatic protected area.<\/p>\n<p>ESD: Electrostatic discharge.<\/p>\n<p>FR4: Flame Retardant 2.<\/p>\n<p>FR4: Flame Retardant 4.<\/p>\n<p>GND: Grounding.<\/p>\n<p>HASL: Hot air solder level.<\/p>\n<p>LGA: Land grid array.<\/p>\n<p>MAR: Mask Annular Ring.<\/p>\n<p>MOQ: Minimum order quantity.<\/p>\n<p>MSL: Moisture sensitivity level.<\/p>\n<p>NSMD: Non-soldermask defined.<\/p>\n<p>OEM: Original equipment manufacturer.<\/p>\n<p>OSP: Organic solderability preservative.<\/p>\n<p>PCB: Printed circuit board.<\/p>\n<p>PIC: Programmable interrupt controller.<\/p>\n<p>PTH: Plated through hole.<\/p>\n<p>PSL: Process sensitivity level.<\/p>\n<p>NPTH: Non plated through hole<\/p>\n<p>QFN: Quad flat package No-lead.<\/p>\n<p>QFP: Quad flat package.<\/p>\n<p>RTV: Room temperature vulcanisation.<\/p>\n<p>RX: R\u00f6ntgen onderzoek.<\/p>\n<p>SMA: Surface mount assembly.<\/p>\n<p>SMD: Surface mount devices. OF solder mask defined.<\/p>\n<p>SMT: Surface mount technology.<\/p>\n<p>SOT: Small outline transistor.<\/p>\n<p>UFP: Ultra fine pitch.<\/p>\n<\/blockquote>\n<\/body>\n<script>\ndocument.getElementById(\"toc-toggle\").onclick = function() {\n  const toc = document.getElementById(\"floating-toc\");\n  toc.style.display = toc.style.display === \"block\" ? \"none\" : \"block\";\n};\n<\/script><\/div><\/div><\/div><\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>Auteur: Bart Lozie Laatste update: 9\/01\/2026 DFM: Tips &amp; Tricks manual Deze bundel werd geschreven voor de klanten van Page [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-templates\/full-width.php","meta":{"footnotes":""},"class_list":["post-65","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/page.be\/electronica\/wp-json\/wp\/v2\/pages\/65","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/page.be\/electronica\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/page.be\/electronica\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/page.be\/electronica\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/page.be\/electronica\/wp-json\/wp\/v2\/comments?post=65"}],"version-history":[{"count":0,"href":"https:\/\/page.be\/electronica\/wp-json\/wp\/v2\/pages\/65\/revisions"}],"wp:attachment":[{"href":"https:\/\/page.be\/electronica\/wp-json\/wp\/v2\/media?parent=65"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}