Semiconductor-Reliability-Training

ReliabilityTrainingPlan2➢ThisshortcourseisintendedtogiveyousomebasicsinReliability➢Contents➢IntroductiontoReliability➢AcceleratedLifeTest•Preconditioning•Moistureresistancetest•Mechanicalrobustnesstest•Dieorientedtest---HTRB•HTS---IMCformationrisk•Solderabilityvs.whiskertest➢Potentialpackagefailure&Riskassessmentvalidation➢Reliabilityqualificationpractice(example:Greenmoldingcompoundqualification)IntroductiontoReliability➢WhatisReliability?Reliabilityistheprobabilityofanitemtoperformarequiredfunctionunderastatedconditionforastatedperiodoftime.➢Definition◆Operatingcondition:•OperatingStress:voltage,current•EnvironmentStress:temperature,temperaturevariation,humidity,pressure,…◆Operatingperiod:•Specifiedperiod(hours/cycles)definedinReliabilityteststandard•Theperiodmaintenanceofqualityorrequiredfunction◆Whatisfailure?FailureistheterminationoftheabilityofanitemtoperformarequiredfunctionFailurecriteria:•Devicenotmeetelectricallimitsdefinedinspecification•Devicenotremainingwithin+/-20%oftheinitialreadout.Forleakagemaximumdrift900%formoisturetest,450%forothertest.)3IntroductiontoReliabilityEarlyFailurePeriodRandomFailurePeriodWearoutFailurePeriodTimeTheidealdistributionwhichbestdescribesthereliabilitybehaviorofmostcomponents4UsefulLifeFailurerateBathtubCurveIntroductiontoreliability➢Earlyfailureperiod•Failuresresultingfromalatentdefectwhichexistsatthebeginningofdevicelifeperiodandnotelectricallydetectable,understresscondition,thedefectdeveloptofailure(electricallydetectable)•Failurerateinearlyfailureperiodishighanddecreasewithtimingpass.•Reliabilitytarget:Trytoreducepotentialprocessdefectcausingainitialfailurebyperiodicscreening(RTCprograminreliabilitylab)5IntroductiontoReliability➢Randomfailureperiod•Thefailureinthisperioddependingonover-stressesappliedtodevicescausedbyaccidentalenvironmentalfactorsandhumanmistakes,etc…•Thefailurerateistimeindependent6Introductiontoreliability•Wear-outfailureperiod•Anydevicewilleventuallyfailevenifnodefects,itisthenaturalagingofdevices•Failurerategraduallyincreasewithtime7IntroductiontoReliability➢ReliabilityMethodologyReliabilitytestsaredoneattwomomentsinthelifeaproduct•Qualification:duringtheproductconceptionorthereisprocess&materialchangeintheproductToprovetheperformancetobequalifiedproductsthroughtheimplementationofreliabilityqualificationplan•Monitoring:duringthemassproductionphase,monitoringoftheproduction(RTCprogram)isinordertoverifythestabilityofprocess.RTCisalistofreliabilityteststhataredoneintheBackEndonsomeproductsinordertodetectprocessshiftProcessQualPackageQualProductQual8IntroductiontoReliability➢ProductsMaturitylevelsMAT00MAT10MAT20MAT30MAT30MAT50MAT60MAT90ConceptDesign&ValidationEngineering/QualificationProductionNPRDACPQCProductionProductterminationLastorderentryEndofcommitmentLastorderproduction&deliveryObsoleteRequestforproductterminationProductsterminatedObsolete9NPR:newproductrequestDAC:designapprovalcertificatePQC:productqualificationcertificateAcceleratedlifetest➢Whatisacceleration?Accelerationmeansthatoperatingadeviceathigherstress(hightemperature,humidity,pressure,voltage,…)producethesamefailuresthatoccursatusestresscondition.➢Whyaccelerated?Itisusedtoreducenecessarylearningtimetounderstand:•Howandwhydevicefailure,toidentifydesignandprocessweakpointsinordertowhat/howtoimprove•WhendeviceexpectedtofailureLifeTimeFailureRateUsefulLifeFailurerateStresstimeAccelerationShorttime-to-marketCostreduction10Acceleratedlifetest➢Stressfactor11EnvironmentalstressOperatingstressStressforcingNaturalTemperatureanditsdriftHumidity,WaterCorrosiveatmospherePressureParticle,dust,bacteriumRadiantraysElectromagneticwavesVoltageCurrentNoiseElectricFieldMagneticFieldSelf-heatingSteadystate/IntermittentTimeNumberofstressFrequencyofcyclingDutycycleChangeofstressSequenceofstressVelocityArtificialSoldering,SolventShock,Drop,VibrationPull,BendingAcceleratedlifetest12➢Byorientation➢BystressfactorDieorientedTestHTRB(HighTemperatureReverseBias)PackageOrientedTestPreconditioningPCT(Pressurecookertest)/U-HASTTC(thermalcycling)/TS(thermalshock)THB(TemperatureHumidityBias)/HASTIOLT(intermittedOperatinglifetest)/TFRSH(Resistancetosolderingtemperature)HTS(Hightemperaturestorage)SolderabilityWhiskerTemperatureonlyHTSTemperaturevariationTC,TSTemperature,humidityPCT,U-HAST,THSTemperature,humidity,voltageTHB,HASTTemperature,currentIOLT,OLTTemperature,VoltageHTRBAcceleratedlifetest➢PreconditioningofSMD•PurposeThepreconditioningsequencetestisusedtosimulatestorageandsolderingenvironmentsofSMDs(SurfaceMountDevices)beforesubmittingthemintodedicatedreliabilitytest,itaimstovalidatetheMSL(MoistureSensitivityLevel)onpackage.•Testscope•Non-hermeticsurfacemountdevices•Preparationforreliabilitytest(PCT,TC,THB,IOLT…)•TestflowBake24hrs(125ºC)InitialelectricaltestMoisturesoakRefertoJ-STD020DReflow3timesFinalelectricaltestReplaceanyfaileddeviceduringinitialreadoutRemoveallthemoistureinsidepackageMoisturerequirementsdependingonMSL,detailrefertonextpageSimulatesolderingprocessatcustomerside.ReworkprocessValidfailure