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Devicequalification:Devicequalification:Devicequalification:Devicequalification:–ELFR(EarlyLifeFailureRate)…JESD22-A108–HTOL(HighTemperatureOperatingLifetest)…JESD22-A108–LTOL(LowTemperatureOperatingLifetest)…JESD22-A108–HTSL(HighTemperatureStorageLifetest)…JESD22-A103
Packagequalification:Packagequalification:Packagequalification:Packagequalification:–Pre-Con.(Pre-conditioning)…JESD22-A113&J-STD-020–HTSL(HighTemperatureStoragetest)…JESD22-A103–HTSL(HighTemperatureStoragetest)…JESD22-A103–LTSL(LowTemperatureStorageLife)…JESD22-A119–THB(TemperatureHumidityBiaslifetest)…JESD22-A101–HAST(Highly-AcceleratedStressTest)…JESD22-A110–UHAST(Un-biasHAST)…JESD22-A118–PCT(PressureCookTest)…JESD22-A102–TCT(TemperatureCyclingTest)…JESD22-A104•Overmanyyears,andacrossawidevarietyofmechanicalandelectroniccomponentsandsystems,peoplehavecalculatedempiricalpopulationfailureratesasunitsageovertimeandrepeatedlyobtainedagraphsuchasshownbelow.Becauseoftheshapeofthisfailureratecurve,ithasbecomewidelyknownastheBathtubcurve.SteadystateDevicequalification(I)(II)(III)WeibullExponentialLog-normal/Weibull~1yearOperationTime10yearHowtoevaluatethereliabilityofICproducts
ItisimpossibletoevaluatethereliabilityofICproductwithnormaloperationconditions.Itwilltakealongtimeandit’simpractical.
HowtoapplyaminimumsamplesizeandshortesttimeperiodtoevaluateICproductreliabilityiscrucial.evaluateICproductreliabilityiscrucial.
Throughacceleratedtest,wecanevaluatethereliabilityofICproductwithminimumsamplesizeandshortesttimeperiod.Somekindofaccelerationtestsstimulateoraccelerateallthepossiblestresses,includingthermal,electrical,humidity,etc.HowtoevaluatethereliabilityofICproductsLTPDTableMax%Defective20%15%10%7%5%3%2%1.5%1%0.7%0.5%AcceptanceNumber(c);rejects=c+1LTPDSamplingTablebasedontheMil-S-19500andMil-M-38510rejects=c+1MinimumSampleSizeNeeded01115223245761161532313284611182538557712919525839055577822534527510517626635453375910563324365941322213334446689531337438527811315826539853179811401599545609113118430846261792713231855ELFRPurpose:It’sperformedtoscreenoutpotentialearlylifefailures.Testcondition:125℃,48~168Hours,1.1Vcc(Vccmaximum)withdynamicpattern.Samplesize:DevicequalificationSamplesize:Hundredstothousandsparts.SeeELFRtable.ReadPoint:48,168ELFRDevicequalificationHTOLPurpose:Tosimulatethedevices’operatingconditioninanacceleratedway,toachieveanequivalentlifepointwithashorterstressduration.Testcondition:125℃,1000Hours,1.1Vcc(Vccmaximum)withdynamicpattern.Devicequalification125℃,1000Hours,1.1Vcc(Vccmaximum)withdynamicpattern.Readpoint:168,500,1000hrs.Example:Ea=0.7evUsetemperature=55℃℃℃℃StressTemperature=125℃℃℃℃Calculatetheaccelerationfactor--Arrheniusequation:DevicequalificationArrheniusequation:1000Hoursstressdurationisequivalent9yearsofuseFailureRate:x⋅1092where,λ=FailureRate(FITS)χ2=FailureEstimateα=1-ConfidenceLevelDevicequalificationFailureRatecalculation:DHAFxTn⋅⋅⋅=+⋅21092)22,(αλFIT(FailureinTime):Failureper109devicehoursn=NumberofFailuresAFT=AccelerationFactorDH=DeviceHoursChi-SquareDistributionFunction60%ConfidenceLevel90%ConfidenceLevelNo.Failsχ2QuantityNo.Failsχ2Quantity01.83304.60514.04517.77926.211210.64538.351313.362410.473415.987Devicequalification410.473415.987512.584518.549614.685621.064716.780723.542818.868825.989920.951928.4121023.0311030.8131125.1061133.1961227.1791235.563LTOLPurpose:It’sperformedtodeterminethereliabilityofdevicesunderlowtemperatureconditionsoveranextendedperiodoftime.TheLTOLtestisusuallyperformedtocheckforhotcarriereffects.Testcondition:DevicequalificationTestcondition:-40℃,1000Hours,1.1Vcc(Vccmaximum)withdynamicpattern.Readpoint:168,500,1000hrs.作業階段作業階段作業階段作業階段客戶須提供資料客戶須提供資料客戶須提供資料客戶須提供資料資料提供時程資料提供時程資料提供時程資料提供時程Survey/QuotePOD/samplesizeSocketmanufactureDummysampleSocket3DevicequalificationOLT作業時程作業時程作業時程作業時程Socketmanufacture(非標準包裝)DummysampleSocket完成前3週BIB/DUT/SocketcardmanufacturePinassignment/Ballout/Applicationcircuit實驗前3週(BIB:實驗前6週)ICverifyPattern(Atpg/Bist)實驗前1週PackagequalificationPre-con•Toensurethatadevicewillbeabletowithstandmultipleassemblycycles.•Pre-conditioningisnowrequiredbeforeallpackagetestElectricalTest1.VisualInspectionby40xOpticalMicroscope2.AcousticMicroscopeExamination(SAT)Temperaturecyclingtest5cycles(Option)Bakefor24Hoursat125(+5/-0)℃MoistureSoakWithin2HoursPlacedevicesinaclean,dry,shallowcontainersothatthepackagebodiesdonottouchoroverlapeachother.Pre-conditionProcedurePackagequalification3HRS24H-1D3HRS192H-8DMoistureSoakLevelIII:30℃/60%R.H,192hrsReflow3cycles:SnPb:220℃/230℃Pb-free:245℃/250℃/260℃5min~60minintervalbetweencyclesWithin15min~4Hours1.VisualInspectionby40xOpticalMicroscope2.AcousticMicroscopeExamination(SAT)ElectricalTest15min(minimum)roomambientcooling1-2cycles:dualsidepcbassembly3rdcycle:rework192H-8D3HRS3HRSMoistureSensitivityLevelsHTS•Purpose:ToevaluatethelifetimeofICproductsthatarestoredinhighambienttemperatureandremaininactiveforseveralyearsbeforetheiractualuse.•Testcondition:150,1000Hours.Packagequalification150℃,1000Hour