SMT設(shè)備原理與應(yīng)用課件

SMT設(shè)備原理與應(yīng)用

PrincipleandApplicationofSMTEquipment2010.9SMT設(shè)備原理與應(yīng)用

PrincipleandAppli1本課程主要講述內(nèi)容，時(shí)間安排，考試安排，實(shí)驗(yàn)，輔導(dǎo)和平時(shí)考勤SMT工藝流程和相關(guān)設(shè)備SMT設(shè)備概述Summarize本課程主要講述內(nèi)容，時(shí)間安排，考試安排，實(shí)驗(yàn)，輔導(dǎo)和平時(shí)考勤2SMT概述與發(fā)展趨勢(shì)4學(xué)時(shí)summaryandtrend焊膏組成與印刷的方式4學(xué)時(shí)solderpastecompositionandprintingtechnology印刷機(jī)原理與應(yīng)用6學(xué)時(shí)principleandapplicationofprinter貼片機(jī)原理與設(shè)備12學(xué)時(shí)principleandapplicationofplacementmachines波峰焊原理與應(yīng)用6學(xué)時(shí)principleandapplicationofwavesolderingoven再流爐原理與應(yīng)用6學(xué)時(shí)principleandapplicationofreflowsolderingoven檢測(cè)設(shè)備

4學(xué)時(shí)inspectionequipment本課程的主要內(nèi)容IncludingSMT概述與發(fā)展趨勢(shì)3SMT生產(chǎn)線(xiàn)參觀（印刷機(jī)、再流爐）2學(xué)時(shí)VisitingSMTproductionline(printer,reflowoven)貼片機(jī)編程原理；2學(xué)時(shí)Mounter(placementmachines)program貼片設(shè)計(jì)性實(shí)驗(yàn)。2學(xué)時(shí)Placementprocessdesignexperiment實(shí)驗(yàn)內(nèi)容experimentcontentSMT生產(chǎn)線(xiàn)參觀（印刷機(jī)、再流爐）2學(xué)時(shí)4期末考試：開(kāi)卷，占總分60%平時(shí)：20%（作業(yè)50%+考勤40%+特別貢獻(xiàn)10%）實(shí)驗(yàn)：20%考試方式testrules期末考試：開(kāi)卷，占總分60%考試方式testrules5聯(lián)系方式indachuan2009@，ldc2005@輔導(dǎo)時(shí)間和地點(diǎn)：地點(diǎn)：時(shí)間：每周輔導(dǎo)時(shí)間和聯(lián)系方式聯(lián)系方式：輔導(dǎo)時(shí)間和聯(lián)系方式6SMT概述與發(fā)展趨勢(shì)SummaryandTrendsSMT概述與發(fā)展趨勢(shì)SummaryandTrends7Surfacemounttechnologywasdevelopedinthe1960sandbecamewidelyusedinthelate1980s.MuchofthepioneeringworkinthistechnologywasbyIBM.ComponentsweremechanicallyredesignedtohavesmallmetaltabsorendcapsthatcouldbedirectlysolderedtothesurfaceofthePCB.Componentsbecamemuchsmallerandcomponentplacementonbothsidesofaboardbecamefarmorecommonwithsurfacemountingthanthrough-holemounting,allowingmuchhighercircuitdensities.Surfacemountinglendsitselfwelltoahighdegreeofautomation,reducinglaborcostandgreatlyincreasingproductionrates.SMDscanbeone-quartertoone-tenththesizeandweight,andone-halftoone-quarterthecostofequivalentthrough-holeparts.SMT技術(shù)發(fā)展歷史和優(yōu)點(diǎn)

HistoryandbenefitsSurfacemounttechnologywasd8SMpDIALECTExpandedFormChinesSMDSurfaceMountDevices(active,passiveandelectromechanicalcomponents)表面貼裝器件SMTSurfaceMountTechnology(assemblingandmontagetechnology)表面貼裝技術(shù)SMASurfaceMountAssembly(moduleassembledwithSMT)表面裝配SMCSurfaceMountComponents(componentsforSMT)表面貼裝組件SMPSurfaceMountPackages(SMDcaseforms)表面貼裝元件封裝形式SMESurfaceMountEquipment(SMTassemblingmachines)表面貼裝設(shè)備常用術(shù)語(yǔ)TermsSMpDIALECTExpandedFormChines9ChipResistorChipResistor10MELFMetalElectrodeFaceresistorsMELFMetalElectrodeFaceresis11chipcapacitorchipcapacitor12chipinductorchipinductor13discretesemiconductordiscretesemiconductor14SOSO15ChipCarrierPlasticLeadlessChipCarrierLeadlessCeramicChipCarrierChipCarrierPlasticLeadlessC16QuadFlatPackageBallgridarrayQuadFlatPackageBallgridarr17SOSmallOutline(4to28pins)小外形結(jié)構(gòu)SOPSmallOutlinePackage(case)小外形封裝SODSmallOutlineDiode小外形封裝分立二極管SOTSmallOutlineTransistor小外形封裝分立三極管SOICSmallOutlineIntegratedCircuit小外形集成電路CCChipCarrier芯片載體LCCLeadlessChipCarrier無(wú)引線(xiàn)芯片載體PLCCPlasticLeadlessChipCarrier塑封無(wú)引線(xiàn)芯片載體LCCCLeadlessCeramicChipCarrier無(wú)引線(xiàn)陶瓷芯片載體MELFMetalElectrodeFaceBonding金屬電極柱形電阻QFPQuadFlatPackage四邊引腳扁平封裝BGAballgridarray球柵陣列封裝SOSmallOutline(4to28pins)18Thesolderjointcon?gurationsoftheICpackagescanberepresentedby?vemajorcategoriesGullwingleads翼型引腳J-leaddesignJ型引腳Butt-leads對(duì)接引腳leadlessBall-lead球形引腳Thesolderjointcon?gurations19Typesofsurfacemountassembly

technology表面組裝技術(shù)的類(lèi)型Typesofsurfacemountassembl20TypeIsurfacemountboardshaveSMCsonlyforbothsidesoftheboardsTypeIsurfacemountboardsha21TypeIIboardshavebothSMCsandTHCsononesideoftheboardandchipcomponentsontheothersideTypeIIboardshavebothSMCs22TypeIIISMThaveTHCsononesideoftheboardandchipcomponentsontheothersideTypeIIISMThaveTHCsonone23Surfacemountsolderingprocess表面組裝焊接類(lèi)型Surfacemountsolderingproces24Wavesoldering適用于通孔裝配技術(shù)THT和通孔元件THC為了減小陰影效應(yīng)（shadowingeffect）,通常采用雙波峰技術(shù)（dualwave）,前面是湍流波（turbulentwave）用于確保所有的引腳潤(rùn)濕，后面的層流波（laminarwave）用于焊接波峰焊僅適用于小的SMCs，大的SMCs和行間距依然是存在橋接（bridge）和焊錫不足等問(wèn)題Wavesoldering適用于通孔裝配技術(shù)THT和通孔元25reflowsoldering使用預(yù)配置好的焊膏（solderpaste）進(jìn)行焊接，焊膏本身可以作為粘接劑焊膏用模版印刷到PCB上采用貼片機(jī)進(jìn)行元件放置在回流爐（reflowoven）中多個(gè)溫區(qū)進(jìn)行整體加熱焊接reflowsolderingreflowsoldering使用預(yù)配置好的焊膏（sold26solderpasteservesnotonlyasasoldermaterial,butalsoasaglue.thedepositionofsolderpasteisusuallyconductedbythestencilorscreenprinting,dispensing,orpin-transferringprocesses.Thepremetereddepositionofsoldermaterialontothesitestobesolderedensuresaconsistentsoldervolumeforthejoints,andaccordinglyeliminatestheinsuf?cientsoldervolumeproblemsduetotheshadowingeffectencounteredbywavesoldering.Inaddition,thispremeteredsolderdepositionalsoreducestheincidenceofbridging.AdvantagesofsolderpastetechnologyinSMTsolderpasteservesnotonlya27theuseofmassre?owprocessallowsawell-controlledgraduateheatingpro?le,thuseliminating

potentialdamageoftheSMCsduetothethermalshockcausedbythewavesolderingtheuseofsolderpasteallowsthepossibilityofstepsoldering.thesolderingperformanceofsolderpasteisnotsensitivetothetypeofsoldermaskusedonthePCBs.Forthewavesolderingprocess,asoldermaskwithasmooth?nishisfoundtocausesolderballandbridgingproblems.AdvantagesofsolderpastetechnologyinSMTtheuseofmassre?owprocess28技術(shù)發(fā)展趨勢(shì)Surfacemounttechnologytrends技術(shù)發(fā)展趨勢(shì)Surfacemounttechnology29TechnologydrivingforceSmallerFasterHighercomplexityLowerpowerLowercostTechnologydrivingforceSmalle30Speedprocessingspeedincreasesapproximately?vetimesinevery5years;resultsfromreductioninbothon-chipdelayinsemiconductorsandpackagingdelaythisimprovementinspeediscloselyassociatedwithminiaturizationofICcomponents,asdemonstratedbythesimultaneousreductioninlinewidthsSpeedprocessingspeedincrease31SMT設(shè)備原理與應(yīng)用課件32ICtransistorintegrationThecomplexityofsemiconductorchipscanbemeasuredbytransistorintegration.microprocessorintegrationhasincreasedby2000×sinceitsintroductionin1970ThisincreaseincomplexityofsemiconductorchipsessentiallydrivestheevolutionofcorrespondingpackagingandassemblytechnologyComplexityICtransistorintegrationCompl33Pincountnumberthepincountnumberwillincreasealmost100×fromthethrough-holetechnologyintheearly1980stomodules/systempackaginginthelate1990s.ComplexityPincountnumberComplexity34ICfeaturesizeDiscretecomponentsizeMiniaturizationICfeaturesizeMiniaturization35AreaarraypackagesAreaarraypackages36Pressureofspeed,complexity,andminiaturizationhavedriventheperipheralpackagedesigndownto0.3mm(16mil)pitchforQFP[17]therapidlyincreasingdefectrateassociatedwithminiaturizationofperipheraldesignwasrecognizedveryquicklyasthebottleneckinfurtherimprovementsinperformance.theassemblydefectrate(ppm)ofQFPisastrongfunctionofthepitchsize.Thedefectrateis25to40ppmfor50milpitch,andgraduallyincreasesto25to100ppmfor30milpitchand40to233ppm(5sigmacontrol)for25milpitch.Thedefectratebecomesprohibitivelyhigh,100to2300ppm,for20milpitch.Thishighdefectrateisprimarilyassociatedwiththevulnerabilityoftheslim,thingullwingleadsofQFPtowardhandling.Thehighprecisionrequiredfortheultra-?ne-pitchcomponentplacementaswellassolderpastedepositionfurtheraggrevatestheproblem.ballgridarray(BGA)Pressureofspeed,complexity,37ballgridarray(BGA)ballgridarray(BGA)38ballgridarray(BGA)ballgridarray(BGA)39chipscalepackages(CSP)ACSPisanICareaarraypackagewithsizenolargerthan1.2×ofICinthelineardimension,ornolargerthan1.5×ofICinarea.chipscalepackages(CSP)ACSP40FlipchipFlipchip41樹(shù)立質(zhì)量法制觀念、提高全員質(zhì)量意識(shí)。12月-2212月-22Tuesday,December20,2022人生得意須盡歡，莫使金樽空對(duì)月。00:16:5000:16:5000:1612/20/202212:16:50AM安全象只弓，不拉它就松，要想保安全，常把弓弦繃。12月-2200:16:5000:16Dec-2220-Dec-22加強(qiáng)交通建設(shè)管理，確保工程建設(shè)質(zhì)量。00:16:5000:16:5000:16Tuesday,December20,2022安全在于心細(xì)，事故出在麻痹。12月-2212月-2200:16:5000:16:50December20,2022踏實(shí)肯干，努力奮斗。2022年12月20日12:16上午12月-2212月-22追求至善憑技術(shù)開(kāi)拓市場(chǎng)，憑管理增創(chuàng)效益，憑服務(wù)樹(shù)立形象。20十二月202212:16:50上午00:16:5012月-22嚴(yán)格把控質(zhì)量關(guān)，讓生產(chǎn)更加有保障。十二月2212:16上午12月-2200:16December20,2022作業(yè)標(biāo)準(zhǔn)記得牢，駕輕就熟除煩惱。2022/12/200:16:5000:16:5020December2022好的事情馬上就會(huì)到來(lái)，一切都是最好的安排。12:16:50上午12:16上午00:16:5012月-22一馬當(dāng)先，全員舉績(jī)，梅開(kāi)二度，業(yè)績(jī)保底。12月-2212月-2200:1600:16:5000:16:50Dec-22牢記安全之責(zé)，善謀安全之策，力務(wù)安全之實(shí)。2022/12/200:16:50Tuesday,December20,2022相信相信得力量。12月-222022/12/200:16:5012月-22謝謝大家！樹(shù)立質(zhì)量法制觀念、提高全員質(zhì)量意識(shí)。12月-2212月-2242樹(shù)立質(zhì)量法制觀念、提高全員質(zhì)量意識(shí)。12月-2212月-22Tuesday,December20,2022人生得意須盡歡，莫使金樽空對(duì)月。00:16:5000:16:5000:1612/20/202212:16:50AM安全象只弓，不拉它就松，要想保安全，常把弓弦繃。12月-2200:16:5000:16Dec-2220-Dec-22加強(qiáng)交通建設(shè)管理，確保工程建設(shè)質(zhì)量。00:16:5000:16:5000:16Tuesday,December20,2022安全在于心細(xì)，事故出在麻痹。12月-2212月-2200:16:5000:16:50December20,2022踏實(shí)肯干，努力奮斗。2022年12月20日12:16上午12月-2212月-22追求至善憑技術(shù)開(kāi)拓市場(chǎng)，憑管理增創(chuàng)效益，憑服務(wù)樹(shù)立形象。20十二月202212:16:50上午00:16:5012月-22嚴(yán)格把控質(zhì)量關(guān)，讓生產(chǎn)更加有保障。十二月2212:16上午12月-2200:16December20,2022作業(yè)標(biāo)準(zhǔn)記得牢，駕輕就熟除煩惱。2022/12/200:16:5000:16:5020December2022好的事情馬上就會(huì)到來(lái)，一切都是最好的安排。12:16:50上午12:16上午00:16:5012月-22一馬當(dāng)先，全員舉績(jī)，梅開(kāi)二度，業(yè)績(jī)保底。12月-2212月-2200:1600:16:5000:16:50Dec-22牢記安全之責(zé)，善謀安全之策，力務(wù)安全之實(shí)。2022/12/200:16:50Tuesday,December20,2022相信相信得力量。12月-222022/12/200:16:5012月-22謝謝大家！樹(shù)立質(zhì)量法制觀念、提高全員質(zhì)量意識(shí)。12月-2212月-2243SMT設(shè)備原理與應(yīng)用

PrincipleandApplicationofSMTEquipment2010.9SMT設(shè)備原理與應(yīng)用

PrincipleandAppli44本課程主要講述內(nèi)容，時(shí)間安排，考試安排，實(shí)驗(yàn)，輔導(dǎo)和平時(shí)考勤SMT工藝流程和相關(guān)設(shè)備SMT設(shè)備概述Summarize本課程主要講述內(nèi)容，時(shí)間安排，考試安排，實(shí)驗(yàn)，輔導(dǎo)和平時(shí)考勤45SMT概述與發(fā)展趨勢(shì)4學(xué)時(shí)summaryandtrend焊膏組成與印刷的方式4學(xué)時(shí)solderpastecompositionandprintingtechnology印刷機(jī)原理與應(yīng)用6學(xué)時(shí)principleandapplicationofprinter貼片機(jī)原理與設(shè)備12學(xué)時(shí)principleandapplicationofplacementmachines波峰焊原理與應(yīng)用6學(xué)時(shí)principleandapplicationofwavesolderingoven再流爐原理與應(yīng)用6學(xué)時(shí)principleandapplicationofreflowsolderingoven檢測(cè)設(shè)備

4學(xué)時(shí)inspectionequipment本課程的主要內(nèi)容IncludingSMT概述與發(fā)展趨勢(shì)46SMT生產(chǎn)線(xiàn)參觀（印刷機(jī)、再流爐）2學(xué)時(shí)VisitingSMTproductionline(printer,reflowoven)貼片機(jī)編程原理；2學(xué)時(shí)Mounter(placementmachines)program貼片設(shè)計(jì)性實(shí)驗(yàn)。2學(xué)時(shí)Placementprocessdesignexperiment實(shí)驗(yàn)內(nèi)容experimentcontentSMT生產(chǎn)線(xiàn)參觀（印刷機(jī)、再流爐）2學(xué)時(shí)47期末考試：開(kāi)卷，占總分60%平時(shí)：20%（作業(yè)50%+考勤40%+特別貢獻(xiàn)10%）實(shí)驗(yàn)：20%考試方式testrules期末考試：開(kāi)卷，占總分60%考試方式testrules48聯(lián)系方式indachuan2009@，ldc2005@輔導(dǎo)時(shí)間和地點(diǎn)：地點(diǎn)：時(shí)間：每周輔導(dǎo)時(shí)間和聯(lián)系方式聯(lián)系方式：輔導(dǎo)時(shí)間和聯(lián)系方式49SMT概述與發(fā)展趨勢(shì)SummaryandTrendsSMT概述與發(fā)展趨勢(shì)SummaryandTrends50Surfacemounttechnologywasdevelopedinthe1960sandbecamewidelyusedinthelate1980s.MuchofthepioneeringworkinthistechnologywasbyIBM.ComponentsweremechanicallyredesignedtohavesmallmetaltabsorendcapsthatcouldbedirectlysolderedtothesurfaceofthePCB.Componentsbecamemuchsmallerandcomponentplacementonbothsidesofaboardbecamefarmorecommonwithsurfacemountingthanthrough-holemounting,allowingmuchhighercircuitdensities.Surfacemountinglendsitselfwelltoahighdegreeofautomation,reducinglaborcostandgreatlyincreasingproductionrates.SMDscanbeone-quartertoone-tenththesizeandweight,andone-halftoone-quarterthecostofequivalentthrough-holeparts.SMT技術(shù)發(fā)展歷史和優(yōu)點(diǎn)

HistoryandbenefitsSurfacemounttechnologywasd51SMpDIALECTExpandedFormChinesSMDSurfaceMountDevices(active,passiveandelectromechanicalcomponents)表面貼裝器件SMTSurfaceMountTechnology(assemblingandmontagetechnology)表面貼裝技術(shù)SMASurfaceMountAssembly(moduleassembledwithSMT)表面裝配SMCSurfaceMountComponents(componentsforSMT)表面貼裝組件SMPSurfaceMountPackages(SMDcaseforms)表面貼裝元件封裝形式SMESurfaceMountEquipment(SMTassemblingmachines)表面貼裝設(shè)備常用術(shù)語(yǔ)TermsSMpDIALECTExpandedFormChines52ChipResistorChipResistor53MELFMetalElectrodeFaceresistorsMELFMetalElectrodeFaceresis54chipcapacitorchipcapacitor55chipinductorchipinductor56discretesemiconductordiscretesemiconductor57SOSO58ChipCarrierPlasticLeadlessChipCarrierLeadlessCeramicChipCarrierChipCarrierPlasticLeadlessC59QuadFlatPackageBallgridarrayQuadFlatPackageBallgridarr60SOSmallOutline(4to28pins)小外形結(jié)構(gòu)SOPSmallOutlinePackage(case)小外形封裝SODSmallOutlineDiode小外形封裝分立二極管SOTSmallOutlineTransistor小外形封裝分立三極管SOICSmallOutlineIntegratedCircuit小外形集成電路CCChipCarrier芯片載體LCCLeadlessChipCarrier無(wú)引線(xiàn)芯片載體PLCCPlasticLeadlessChipCarrier塑封無(wú)引線(xiàn)芯片載體LCCCLeadlessCeramicChipCarrier無(wú)引線(xiàn)陶瓷芯片載體MELFMetalElectrodeFaceBonding金屬電極柱形電阻QFPQuadFlatPackage四邊引腳扁平封裝BGAballgridarray球柵陣列封裝SOSmallOutline(4to28pins)61Thesolderjointcon?gurationsoftheICpackagescanberepresentedby?vemajorcategoriesGullwingleads翼型引腳J-leaddesignJ型引腳Butt-leads對(duì)接引腳leadlessBall-lead球形引腳Thesolderjointcon?gurations62Typesofsurfacemountassembly

technology表面組裝技術(shù)的類(lèi)型Typesofsurfacemountassembl63TypeIsurfacemountboardshaveSMCsonlyforbothsidesoftheboardsTypeIsurfacemountboardsha64TypeIIboardshavebothSMCsandTHCsononesideoftheboardandchipcomponentsontheothersideTypeIIboardshavebothSMCs65TypeIIISMThaveTHCsononesideoftheboardandchipcomponentsontheothersideTypeIIISMThaveTHCsonone66Surfacemountsolderingprocess表面組裝焊接類(lèi)型Surfacemountsolderingproces67Wavesoldering適用于通孔裝配技術(shù)THT和通孔元件THC為了減小陰影效應(yīng)（shadowingeffect）,通常采用雙波峰技術(shù)（dualwave）,前面是湍流波（turbulentwave）用于確保所有的引腳潤(rùn)濕，后面的層流波（laminarwave）用于焊接波峰焊僅適用于小的SMCs，大的SMCs和行間距依然是存在橋接（bridge）和焊錫不足等問(wèn)題Wavesoldering適用于通孔裝配技術(shù)THT和通孔元68reflowsoldering使用預(yù)配置好的焊膏（solderpaste）進(jìn)行焊接，焊膏本身可以作為粘接劑焊膏用模版印刷到PCB上采用貼片機(jī)進(jìn)行元件放置在回流爐（reflowoven）中多個(gè)溫區(qū)進(jìn)行整體加熱焊接reflowsolderingreflowsoldering使用預(yù)配置好的焊膏（sold69solderpasteservesnotonlyasasoldermaterial,butalsoasaglue.thedepositionofsolderpasteisusuallyconductedbythestencilorscreenprinting,dispensing,orpin-transferringprocesses.Thepremetereddepositionofsoldermaterialontothesitestobesolderedensuresaconsistentsoldervolumeforthejoints,andaccordinglyeliminatestheinsuf?cientsoldervolumeproblemsduetotheshadowingeffectencounteredbywavesoldering.Inaddition,thispremeteredsolderdepositionalsoreducestheincidenceofbridging.AdvantagesofsolderpastetechnologyinSMTsolderpasteservesnotonlya70theuseofmassre?owprocessallowsawell-controlledgraduateheatingpro?le,thuseliminating

potentialdamageoftheSMCsduetothethermalshockcausedbythewavesolderingtheuseofsolderpasteallowsthepossibilityofstepsoldering.thesolderingperformanceofsolderpasteisnotsensitivetothetypeofsoldermaskusedonthePCBs.Forthewavesolderingprocess,asoldermaskwithasmooth?nishisfoundtocausesolderballandbridgingproblems.AdvantagesofsolderpastetechnologyinSMTtheuseofmassre?owprocess71技術(shù)發(fā)展趨勢(shì)Surfacemounttechnologytrends技術(shù)發(fā)展趨勢(shì)Surfacemounttechnology72TechnologydrivingforceSmallerFasterHighercomplexityLowerpowerLowercostTechnologydrivingforceSmalle73Speedprocessingspeedincreasesapproximately?vetimesinevery5years;resultsfromreductioninbothon-chipdelayinsemiconductorsandpackagingdelaythisimprovementinspeediscloselyassociatedwithminiaturizationofICcomponents,asdemonstratedbythesimultaneousreductioninlinewidthsSpeedprocessingspeedincrease74SMT設(shè)備原理與應(yīng)用課件75ICtransistorintegrationThecomplexityofsemiconductorchipscanbemeasuredbytransistorintegration.microprocessorintegrationhasincreasedby2000×sinceitsintroductionin1970ThisincreaseincomplexityofsemiconductorchipsessentiallydrivestheevolutionofcorrespondingpackagingandassemblytechnologyComplexityICtransistorintegrationCompl76Pincountnumberthepincountnumberwillincreasealmost100×fromthethrough-holetechnologyintheearly1980stomodules/systempackaginginthelate1990s.ComplexityPincountnumberComplexity77ICfeaturesizeDiscretecomponentsizeMiniaturizationICfeaturesizeMiniaturization78AreaarraypackagesAreaarraypackages79Pressureofspeed,complexity,andminiaturizationhavedriventheperipheralpackagedesigndownto0.3mm(16mil)pitchforQFP[17]therapidlyincreasingdefectrateassociatedwithminiaturizationofperipheraldesignwasrecognizedveryquicklyasthebottleneckinfurtherimprovementsinperformance.theassemblydefectrate(ppm)ofQFPisastrongfunctionofthepitchsize.Thedefectrateis25to40ppmfor50milpitch,andgraduallyincreasesto25to100ppmfor30milpitchand40to233ppm(5sigmacontrol)for25milpitch.Thedefectratebecomesprohibitivelyhigh,100to2300ppm,for20milpitch.Thishighdefectrateisprimarilyassociatedwiththevulnerabilityoftheslim,thingullwingleadsofQFPtowardhandling.Thehighprecisionrequiredfortheultra-?ne-pitchcomponentplacementaswellassolderpastedepositionfurtheraggrevatestheproblem.b