SMT设备原理与应用

SMT设备原理与应用

PrincipleandApplicationofSMTEquipment2010.9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SummarizeSMT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IncludingSMT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indachuan2009@，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SummaryandTrendsSurfacemounttechnologywasdevelopedinthe1960sandbecamewidelyusedinthelate1980s.MuchofthepioneeringworkinthistechnologywasbyIBM.ComponentsweremechanicallyredesignedtohavesmallmetaltabsorendcapsthatcouldbedirectlysolderedtothesurfaceofthePCB.Componentsbecamemuchsmallerandcomponentplacementonbothsidesofaboardbecamefarmorecommonwithsurfacemountingthanthrough-holemounting,allowingmuchhighercircuitdensities.Surfacemountinglendsitselfwelltoahighdegreeofautomation,reducinglaborcostandgreatlyincreasingproductionrates.SMDscanbeone-quartertoone-tenththesizeandweight,andone-halftoone-quarterthecostofequivalentthrough-holeparts.SMT技术发展历史和优点

HistoryandbenefitsSMpDIALECTExpandedFormChinesSMDSurfaceMountDevices(active,passiveandelectromechanicalcomponents)表面贴装器件SMTSurfaceMountTechnology(assemblingandmontagetechnology)表面贴装技术SMASurfaceMountAssembly(moduleassembledwithSMT)表面装配SMCSurfaceMountComponents(componentsforSMT)表面贴装组件SMPSurfaceMountPackages(SMDcaseforms)表面贴装元件封装形式SMESurfaceMountEquipment(SMTassemblingmachines)表面贴装设备常用术语TermsChipResistorMELFMetalElectrodeFaceresistorschipcapacitorchipinductordiscretesemiconductorSOChipCarrierPlasticLeadlessChipCarrierLeadlessCeramicChipCarrierQuadFlatPackageBallgridarraySOSmallOutline(4to28pins)小外形结构SOPSmallOutlinePackage(case)小外形封装SODSmallOutlineDiode小外形封装分立二极管SOTSmallOutlineTransistor小外形封装分立三极管SOICSmallOutlineIntegratedCircuit小外形集成电路CCChipCarrier芯片载体LCCLeadlessChipCarrier无引线芯片载体PLCCPlasticLeadlessChipCarrier塑封无引线芯片载体LCCCLeadlessCeramicChipCarrier无引线陶瓷芯片载体MELFMetalElectrodeFaceBonding金属电极柱形电阻QFPQuadFlatPackage四边引脚扁平封装BGAballgridarray球栅阵列封装ThesolderjointconfigurationsoftheICpackagescanberepresentedbyfivemajorcategoriesGullwingleads翼型引脚J-leaddesignJ型引脚Butt-leads对接引脚leadlessBall-lead球形引脚Typesofsurfacemountassembly

technology表面组装技术的类型TypeIsurfacemountboardshaveSMCsonlyforbothsidesoftheboardsTypeIIboardshavebothSMCsandTHCsononesideoftheboardandchipcomponentsontheothersideTypeIIISMThaveTHCsononesideoftheboardandchipcomponentsontheothersideSurfacemountsolderingprocess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reflowsolderingsolderpasteservesnotonlyasasoldermaterial,butalsoasaglue.thedepositionofsolderpasteisusuallyconductedbythestencilorscreenprinting,dispensing,orpin-transferringprocesses.Thepremetereddepositionofsoldermaterialontothesitestobesolderedensuresaconsistentsoldervolumeforthejoints,andaccordinglyeliminatestheinsufficientsoldervolumeproblemsduetotheshadowingeffectencounteredbywavesoldering.Inaddition,thispremeteredsolderdepositionalsoreducestheincidenceofbridging.AdvantagesofsolderpastetechnologyinSMTtheuseofmassreflowprocessallowsawell-controlledgraduateheatingprofile,thuseliminating

potentialdamageoftheSMCsduetothethermalshockcausedbythewavesolderingtheuseofsolderpasteallowsthepossibilityofstepsoldering.thesolderingperformanceofsolderpasteisnotsensitivetothetypeofsoldermaskusedonthePCBs.Forthewavesolderingprocess,asoldermaskwithasmoothfinishisfoundtocausesolderballandbridgingproblems.AdvantagesofsolderpastetechnologyinSMT技术发展趋势SurfacemounttechnologytrendsTechnologydrivingforceSmallerFasterHighercomplexityLowerpowerLowercostSpeedprocessingspeedincreasesapproximatelyfivetimesinevery5years;resultsfromreductioninbothon-chipdelayinsemiconductorsandpackagingdelaythisimprovementinspeediscloselyassociatedwithminiaturizationofICcomponents,asdemonstratedbythesimultaneousreductioninlinewidthsICtransistorintegrationThecomplexityofsemiconductorchipscanbemeasuredbytransistorintegration.microprocessorintegrationhasincreasedby2000×sinceitsintroductionin1970ThisincreaseincomplexityofsemiconductorchipsessentiallydrivestheevolutionofcorrespondingpackagingandassemblytechnologyComplexityPincountnumberthepincountnumberwillincreasealmost100×fromthethrough-holetechnologyintheearly1980stomodules/systempackaginginthelate1990s.ComplexityICfeaturesizeDiscretecomponentsizeMiniaturizationAreaarraypackagesPressureofspeed,complexity,andminiaturizationhavedriventheperipheralpackagedesigndownto0.3mm(16mil)pitchforQFP[17]therapidlyincreasingdefectrateassociatedwithminiaturizationofperipheraldesignwasrecognizedveryquicklyasthebottleneckinfurtherimprovementsinperformance.theassemblydefectrate(ppm)ofQFPisastrongfunctionofthepitchsize.Thedefect