SMT设备原理与应用PrincipleandApplicationofSMTEquipment 2010 9 本课程主要讲述内容 时间安排 考试安排 实验 辅导和平时考勤SMT工艺流程和相关设备 SMT设备概述Summarize SMT概述与发展趋势4学时summaryandtrend焊膏组成与印刷的方式4学时solderpastecompositionandprintingtechnology印刷机原理与应用6学时principleandapplicationofprinter贴片机原理与设备12学时principleandapplicationofplacementmachines波峰焊原理与应用6学时principleandapplicationofwavesolderingoven再流炉原理与应用6学时principleandapplicationofreflowsolderingoven检测设备4学时inspectionequipment 本课程的主要内容Including SMT生产线参观 印刷机 再流炉 2学时VisitingSMTproductionline printer reflowoven 贴片机编程原理 2学时Mounter placementmachines program贴片设计性实验 2学时Placementprocessdesignexperiment 实验内容experimentcontent 期末考试 开卷 占总分60 平时 20 作业50 考勤40 特别贡献10 实验 20 考试方式testrules 联系方式 13737744076lindachuan2009 ldc2005 辅导时间和地点 地点 时间 每周 辅导时间和联系方式 SMT概述与发展趋势 SummaryandTrends Surfacemounttechnologywasdevelopedinthe1960sandbecamewidelyusedinthelate1980s MuchofthepioneeringworkinthistechnologywasbyIBM ComponentsweremechanicallyredesignedtohavesmallmetaltabsorendcapsthatcouldbedirectlysolderedtothesurfaceofthePCB Componentsbecamemuchsmallerandcomponentplacementonbothsidesofaboardbecamefarmorecommonwithsurfacemountingthanthrough holemounting allowingmuchhighercircuitdensities Surfacemountinglendsitselfwelltoahighdegreeofautomation reducinglaborcostandgreatlyincreasingproductionrates SMDscanbeone quartertoone tenththesizeandweight andone halftoone quarterthecostofequivalentthrough holeparts SMT技术发展历史和优点Historyandbenefits 常用术语Terms ChipResistor chipcapacitor chipinductor discretesemiconductor SO ChipCarrier PlasticLeadlessChipCarrier LeadlessCeramicChipCarrier QuadFlatPackage Ballgridarray Thesolderjointcon gurationsoftheICpackagescanberepresentedby vemajorcategories Gullwingleads翼型引脚 J leaddesignJ型引脚 Butt leads对接引脚 leadless Ball lead球形引脚 Typesofsurfacemountassemblytechnology 表面组装技术的类型 TypeIsurfacemountboardshaveSMCsonlyforbothsidesoftheboards TypeIIboardshavebothSMCsandTHCsononesideoftheboardandchipcomponentsontheotherside TypeIIISMThaveTHCsononesideoftheboardandchipcomponentsontheotherside Surfacemountsolderingprocess 表面组装焊接类型 Wavesoldering 适用于通孔装配技术THT和通孔元件THC为了减小阴影效应 shadowingeffect 通常采用双波峰技术 dualwave 前面是湍流波 turbulentwave 用于确保所有的引脚润湿 后面的层流波 laminarwave 用于焊接波峰焊仅适用于小的SMCs 大的SMCs和行间距依然是存在桥接 bridge 和焊锡不足等问题 reflowsoldering 使用预配置好的焊膏 solderpaste 进行焊接 焊膏本身可以作为粘接剂焊膏用模版印刷到PCB上采用贴片机进行元件放置在回流炉 reflowoven 中多个温区进行整体加热焊接 reflowsoldering solderpasteservesnotonlyasasoldermaterial butalsoasaglue thedepositionofsolderpasteisusuallyconductedbythestencilorscreenprinting dispensing orpin transferringprocesses Thepremetereddepositionofsoldermaterialontothesitestobesolderedensuresaconsistentsoldervolumeforthejoints andaccordinglyeliminatestheinsuf cientsoldervolumeproblemsduetotheshadowingeffectencounteredbywavesoldering Inaddition thispremeteredsolderdepositionalsoreducestheincidenceofbridging AdvantagesofsolderpastetechnologyinSMT theuseofmassre owprocessallowsawell controlledgraduateheatingpro le thuseliminatingpotentialdamageoftheSMCsduetothethermalshockcausedbythewavesolderingtheuseofsolderpasteallowsthepossibilityofstepsoldering thesolderingperformanceofsolderpasteisnotsensitivetothetypeofsoldermaskusedonthePCBs Forthewavesolderingprocess asoldermaskwithasmooth nishisfoundtocausesolderballandbridgingproblems AdvantagesofsolderpastetechnologyinSMT 技术发展趋势 Surfacemounttechnologytrends Technologydrivingforce SmallerFasterHighercomplexityLowerpowerLowercost Speed processingspeedincreasesapproximately vetimesinevery5years resultsfromreductioninbothon chipdelayinsemiconductorsandpackagingdelaythisimprovementinspeediscloselyassociatedwithminiaturizationofICcomponents asdemonstratedbythesimultaneousreductioninlinewidths ICtransistorintegrationThecomplexityofsemiconductorchipscanbemeasuredbytransistorintegration microprocessorintegrationhasincreasedby2000 sinceitsintroductionin1970Thisincreaseincomplexityofsemiconductorchipsessentiallydrivestheevolutionofcorrespondingpackagingandassemblytechnology Complexity Pincountnumberthepincountnumberwillincreasealmost100 fromthethrough holetechnologyintheearly1980stomodules systempackaginginthelate1990s Complexity ICfeaturesizeDiscretecomponentsize Miniaturization Areaarraypackages Pressureofspeed complexity andminiaturizationhavedriventheperipheralpackagedesigndownto0 3mm 16mil pitchforQFP 17 therapidlyincreasingdefectrateassociatedwithminiaturizationofperipheraldesignwasrecognizedveryquicklyasthebottleneckinfurtherimprovementsinperformance theassemblydefectrate ppm ofQFPisastrongfunctionofthepitchsize Thedefectrateis25to40ppmfor50milpitch andgraduallyincreasesto25to100ppmfor30milpitchand40to233ppm 5sigmacontrol for25milpitch Thedefectratebecomesprohibitivelyhigh 100to2300ppm for20milpitch Thishighdefectrateisprimarilyassociatedwiththevulnerabilityoftheslim thingullwingleadsofQFPtowardhandling Thehighprecisionrequiredfortheultra ne pitchcomponentplacementaswellassolderpastedepositionfurtheraggrevatestheproblem ballgridarray BGA ballgridarray BGA ballgridarray BGA chipscalepackages CSP ACSPisanICareaarraypa