Lesson-51PCB知识

PCB知识介绍PreparebyXuChengzeY2004PCB的种类（PRINTEDCIRCUITBOARDTYPE）普通的PCB板RIGIDPCB柔性PCB板–FLEXPCB刚柔性PCB板RIGID-FLEXPCB按PCB基材强度分类按制作方法分类加成法AdditiveBoard减成法SubtractiveBoard按基材分类（COPPERCLADLAMINATES）纸基板：酚醛树脂覆铜板FR-1/FR-2，XXXPC，XPC（IMPREGNATINGINSULATIONPAPER）环氧树脂覆铜板FR-3聚酯树脂覆铜板玻璃布基板：环氧树脂覆铜板FR-4，G10（GLASSFIBERPAPER）耐热环氧树脂覆铜板FR-5，G11聚酰亚胺树脂覆铜板GPY复合基板：纸（内）/玻璃布（外）环氧树脂覆铜板CME-1玻璃纤维（内）/玻璃布（外）环氧树脂覆铜板CEM-3其他基板：金属基型/芯型陶瓷基：氧化铝/氮化铝耐热热塑性基板：聚酰亚胺树脂板感光干膜按复杂程度SINGLESIDEPCB/DOUBLESIDEPCBMULTI-LAYERSPCB目前PCB原材料厂家中国：生益/台湾地区：建滔/南亚韩国：斗山日本：National/京瓷美国：Nelco/GE/Dupond/Cookson组成基材CCL（COPPERCLADLAMINATES）的原材料1.铜箔COPPERFOIL）压延–ROLLEDCOPPERFOIL99.9%纯度（用于音响/高频传输）电解–ELECTRODEPOSITEDCOPPER（E5u/Q9u/T12u/H1/2oz/M3/4oz/11oz)2.浸渍绝缘纸（IMPREGNATINGINSULATIONPAPER）3.玻纤布（GLASSFIBERPAPER）4.高分子树脂（POLYMERRESIN）PI/PTFE/BT/PPE（POLYPHENYLENEOXID）生产技术加成法全加成法FULLADDITIVEPROCESS半加成法SEMIADDITIVEPROCESS部分加成法PARTIALADDITIVEPROCESS减成法非孔化NON-PLATING-THROUGH-HOLEBOARD孔化PLATING-THROUGH-HOLEBOARD图形电镀PATTERNPTN图形电镀蚀刻PATTERNPLATINGANDETCHINGPROCESS裸铜覆阻焊工艺SOLDERMASKONBARECOPPER全板电镀PANELPNL关键技术参数：1.导线的粗细与密集程度线宽和间距TRACKDIA:0.20mm0.130.080.05铜厚COPPERTHICKNESS:3oz2oz1oz3/4oz1/2oz12um9um5um2.板厚10mm6mm(above20layers)2mm1.6mm1.2mm1.0mm0.8mm0.8mm(8layers)0.6mm(6layers)0.4mm(4-6layers)3.过孔的直径大小0.2mm0.1mm0.08mm0.05mm数控钻微型钻激光打孔4.电路密集/复杂是否存在埋，盲，通孔技术5.是否有CTI值和阻抗要求6.是否为高频板和高温板7.表面处理需要什么特别（例如局部镀金，金手指，COB焊盘等）硬金HardGold:浸金是指以置换的模式将金析出于镍表面，浓度相当薄且无法继续成长化学金是用氧化还原剂的模式将金还原在镍面上，浓度可调，稳定性差硬度高，使用金手指或其他适配卡，内存卡软金SoftGodl:以电镀的模式析出镍金，浓度好控制，用与IC封装打线。PCB是如何制造出来的呢？通用电脑的健盘就能看到一张软性薄膜（挠性的绝缘基材），印上有银白色（银浆）的导电图形与健位图形。因为通用丝网漏印方法得到这种图形，所以我们称这种印制线路板为挠性银浆印制线路板。各种电脑主机板、显卡、网卡、调制解调器、声卡及家用电器上的印制电路板，它所用的基材是由纸基（常用于单面）或玻璃布基（常用于双面及多层），预浸酚醛或环氧树脂，表层一面或两面粘上覆铜簿再层压固化而成。这种线路板覆铜簿板材，我们就称它为刚性板。再制成印制线路板，我们就称它为刚性印制线路板。单面有印制线路图形我们称单面印制线路板，双面有印制线路图形，再通过孔的金属化进行双面互连形成的印制线路板，我们就称其为双面板。如果用一块双面作内层、二块单面作外层或二块双面作内层、二块单面作外层的印制线路板，通过定位系统及绝缘粘结材料交替在一起且导电图形按设计要求进行互连的印制线路板就成为四层、六层印制电路板了，也称为多层印制线路板。现在已有超过100层的实用印制线路板了。单面刚性印制板：→单面覆铜板→下料→（刷洗、干燥）→钻孔或冲孔→网印线路抗蚀刻图形或使用干膜→固化检查修板→蚀刻铜→去抗蚀印料、干燥→刷洗、干燥→网印阻焊图形（常用绿油）、UV固化→网印字符标记图形、UV固化→预热、冲孔及外形→电气开、短路测试→刷洗、干燥→预涂助焊防氧化剂（干燥）或喷锡热风整平→检验包装→成品出厂。双面刚性印制板：→双面覆铜板→下料→叠板→数控钻导通孔→检验、去毛刺刷洗→化学镀（导通孔金属化）→（全板电镀薄铜）→检验刷洗→网印负性电路图形、固化（干膜或湿膜、曝光、显影）→检验、修板→线路图形电镀→电镀锡（抗蚀镍/金）→去印料（感光膜）→蚀刻铜→（退锡）→清洁刷洗→网印阻焊图形常用热固化绿油（贴感光干膜或湿膜、曝光、显影、热固化，常用感光热固化绿油）→清洗、干燥→网印标记字符图形、固化→（喷锡或有机保焊膜）→外形加工→清洗、干燥→电气通断检测→检验包装→成品出厂。贯通孔金属化法制造多层板工艺流程→内层覆铜板双面开料→刷洗→钻定位孔→贴光致抗蚀干膜或涂覆光致抗蚀剂→曝光→显影→蚀刻与去膜→内层粗化、去氧化→内层检查→（外层单面覆铜板线路制作、B—阶粘结片、板材粘结片检查、钻定位孔）→层压→数控制钻孔→孔检查→孔前处理与化学镀铜→全板镀薄铜→镀层检查→贴光致耐电镀干膜或涂覆光致耐电镀剂→面层底板曝光→显影、修板→线路图形电镀→电镀锡铅合金或镍/金镀→去膜与蚀刻→检查→网印阻焊图形或光致阻焊图形→印制字符图形→（热风整平或有机保焊膜）→数控洗外形→清洗、干燥→电气通断检测→成品检查→包装出厂。BasicPCBConstruction&Terminology(基本术语）Laminates(Cores)基材•Fullycuredfiberglass-resinSystem•CopperClad•Indentifiedbycorethickness,copperweightPrepregs（树脂浸蕴层）•Pre-impregnatedbondinglayers•Partiallycuredfiberglass-resinsystem•IdentifiedbyglasstypeCopperfoils（铜箔）*Electrodeposited(ED)std&DSTF*1Oz=0.0014”=0.035mm=35umLaminatesConstructionThicknessandTolerancesforLaminates(0.032”)Forexample:EliteMaterialCo.,ltdEM822SPECTABLEThicknessandTolerancesforLaminates(0.032”)PrepregsForexample:GETEKML2000SerialsInnerlayer1).ChemicalCleaningRemovestheanti-tarnishcoating,dirt,grease,fromthecopperCladlaminate2).DryFilmLamination:ApplicationofanUVsensitivedryfilmtothecleanedsurfaceofthecopperlaminate.UtilizesafullyautomatedCutsheetlaminator(CSL)whichapplierdryfilmonbothsidessidesofthecopperlaminatethroughcontrolledheatandpressure.3).DryFilmExposure:Anegativephototoolorartworkisimagedintothedryfilm,onbothsidesofthecopperclad,throughUVlightexposureleavingapositiveimageinthedryfilm.DuringexposuretheUVenergyisabsorbedbythedryfilmdirectlyunderneaththeclearAreasoftheoverlayingartwork,causingittopolymerizeandharden.Thefilmcoveredbydarkareasoftheartworkremainssoft.4).DryfilmdevelopingAfterthedryfilmisimaged,theunexposedsoftareasofthedissolvedawaywhilethehardeneddryfilmremainsunaffected5).CopperEtch:TheremaininghardeneddryfilmonthecopperActsasa“Resist”andtheunprotectedcopperIschemicallydissolvedoretched.6).StripResist:ThehardeneddryfilmisstrippedfromtheCopperleavingthedesiredcopperpatternReproducedfromtheartwork.Theinner-layerImagetransferprocesshasbeencompleted.7).Post-Etch–Punch(PEP)ThisprocesspunchestoolingholeswhichAreusedtoaligninner-layercoresinsubsequentprocess.ThePEPutilizesacamerasystemwithtargetsimagedinthecoppertolocateandpunchtoolingholeswithaveryhighaccurace.8).AutomatedOpticalInspection(AOI)Inner-layercoresareinspectedwiththeuseofacomputeraidedopticalinspectionsystemtolocateanypatterndefectthatmayhaveoccurredduringtheimagetransferprocessTheAOIprocessusesadatafilegeneratedatCAM.Themachinecomparestheimagescannedversusagraphiccomputerfile.AOIbenefitsconsistofearlydetectionofprocessdeviations,reductionoffinaltestfallout’s,consistentlinewidthandtolerances.RepairscanbemadeheretoweldinnerlayersopensorTriminnerlayershortspercustomerspecifications.9).Inner-layerOxideThisprocessisdesignedtointentionallycreateacoatingofcopperoxideontothecoppercircuitrytoenhancethesurf