[PDF] Practical Approach to Determining SSD Reliability - Flash Memory PDF 20150812_TT2

Applying our testing framework, we test 17 commodity SSDs from six different vendors using more than three thousand fault injection cycles in total Our

[PDF] Reliability and MTBF Demonstration Testing For Solid State Drives

Reliability and MTBF Demonstration Testing For Solid State Drives Because of DfR Solutions' in-depth understanding of solid state drive (SSD) technology,

SSD next gen RDT - IEEE Xplore

Reliability Demonstration Test (RDT) is an essential part of the overall product reliability development life cycle validation and it is required by all customers This paper discusses the different ways to determine the acceleration factor required to plan the Solid State Drive (SSD) reliability demonstration test

A Competing Risk Model of Reliability Analysis for - IEEE Xplore

5 mar 2019 · Since 2008, JEDEC commissioned a group of drives cus- tomers, SSD manufacturers, and NAND component man- ufactures to develop

[PDF] SSD - JEDEC STANDARD

SOLID STATE DRIVE (SSD) REQUIREMENTS AND ENDURANCE TEST transient failure is an SSD that fails during a reliability stress but passes in the final

[PDF] Failure Analysis and Reliability Study of NAND Flash - CORE

18 déc 2015 · analyze the root cause of Quality, Endurance component Reliability Demonstration Test (RDT) failures and determine SSD performance

[PDF] Solid State Storage Performance Test Specification - SNIA

As NAND Flash becomes more reliable and affordable, solid state drives (SSD) will increasingly complement HDDs by improving system performance 1 The

[PDF] Understanding SSD Performance Using the SNIA SSS Performance

SSD Test Best Practices 31 15 Conclusion What test platform was used to test the SSD? About SNIA Solid State Storage Performance Test Specification ( PTS) used to ensure the repeatability and reliability of the test measurements

[PDF] ssl vpn certificate sonicwall

[PDF] ssl vpn fortigate

[PDF] st luke's hospital houston bertner cafe menu

[PDF] st malo coronavirus

[PDF] st thomas port guide

[PDF] staff eating breakfast at work

[PDF] stage culture hauts de france

[PDF] stages in language acquisition

[PDF] stages of bilingual language development

[PDF] stages of language acquisition pdf

[PDF] stages of language acquisition ppt

[PDF] stakeholder engagement

[PDF] stakeholder engagement pdf

[PDF] stakeholder engagement plan

[PDF] stakeholder engagement strategy

©2014 Micron Technology, Inc. All rights reserved. Products are warranted only to meet Micron's production data sheet specifications. Information, products, and/or specifications are subject to change without notice. All information is provided on an "AS IS" basis without warranties of any kind. Dates are estimates only. Drawings are not to scale. Micron and the Micron logo are trademarks of Micron Technology, Inc. All other trademarks are the property of their respective owners.|©2 14MicronTechnology,Inc.|MicronConfidential1PracticalApproachtoDeterminingSSDReliabilityToddMarquart,Ph.D,Fellow-MicronTechnologyAugust25,2 15

|©2 14MicronTechnology,Inc.|MicronConfidential2SomeInitialDefinitionsandAcronyms•TotalBytesWritten(TBW):▪Thisistheamountofdatatransferredbytthehost.Typicallybase1 .•LogicalorUserDensity:▪Thisisthetotalamountofdataausercanstoreonadriveatanygivenmoment.Typicallybase1 .•PhysicalDensity:▪Thetotalamountofstoragephysicallyonthedrive,typicallybase2.•WriteAmplification(WA):▪AmeasureofhowmuchdataisactuallywrittentotheSSDcomparedtowhatwasrequestedbythehost.•MeanTimeToFailure(MTTF):▪Thepositionparameteroftheexponentialdistributionbasedonthetimetofirstfailure.▪Theexponentialdistributionappliestofailuresthataretrulyrandom.▪MTBF(MeanTimeBetweenFailure):Onlyvalidforarepairablesystem.•AnnualizedFailureRate(AFR):▪Thefailureprobabilityin1year,constantforanexponentialdistribution.August25,2 15

|©2 14MicronTechnology,Inc.3ReliabilityStatistics300.20.40.60.8100.511.52Fraction Failingβ=0.1β=1.0β=4.0Multiples of η00.511.52Multiples of ηβ=0.1β=1.0β=4.000.511.52β=0.1β=1.0β=4.0Multiples of ηH(t):HazardFunction.f(t):ProbabilityDistributionFunction(PDF))()()(1)()(tStftFtftH=-=FunctionSurvivor S(t) :Where )(1)(=-=tStFdtdFtf=)(F(t):CumulativeDistributionFunction(CDF).

|©2 14MicronTechnology,Inc.4ReliabilityStatistics•Whatisit?▪Largefamilyofdistributionsthatcovertheentirelifeofmanyproducts.•Whatisitgoodfor?▪ManyfailuremodescanbedescribedwithorapproximatedbyaWeibulldistribution.ThelognormalisnotcoveredbytheWeibullfamily.TodistinguishWeibullfromlognormalrequiresatleast2 pointsofGOODdata.▪Workswellwithverysmallsamplesizes.Analysisispossiblewith1oreven failures.▪Goodstartingpointformostanalyses.Ifthedataisactuallylognormal,theWeibulldistributionwillgivemoreconservativeextrapolatedlifetimesmakingitasaferstartingpoint.▪Weakestlinkdistribution.•Whataretheparameters?▪ßistheshapeorslopeparameter.ItistheslopeofthelinewhenplottedonWeibullpaper.▪ß=1givestheexponentialdistribution.▪ηisthecharacteristiclifeorscaleparameter.Itisthetimeto63.2%failure.4•WeibullDistribution!!"#$$%&''()**+,--=βηttFexp1)(!!"#$$%&''()**+,-''()**+,=ββηβηttttfexp)(tttHβηβ##$%&&'(=)(

|©2 14MicronTechnology,Inc.5ReliabilityStatistics•Ingeneralitisadvantageoustoplotdistributionsonaxesthatgeneratestraightlinesinordertojudgethefitofthedata,examinesignsofcurvatureetc...5())))(1ln(ln(ln)ln()(11lnlntFßtßtF--=-=""#$%%&'-η!!"#$$%&''()**+,--=βηttFexp1)(WeibullCDF:Y=mX+b

|©2 14MicronTechnology,Inc.6ReliabilityStatistics•AplotoftheWeibullCDFgivesagood,intuitiveviewoftheproductlifetime.•ThesamereliabilitymechanismswilltendtohavethesameWeibullslopeevenwhenchangingfromonetechnodetoanother.6

|©2 14MicronTechnology,Inc.7ReliabilityStatistics•Historicalviewofoverallreliabilitylifetime.•Notmyfavoriteview.7EarlyLifeUsefulLifeEarlyWearoutEndofLifeWearout

|©2 14MicronTechnology,Inc.8AccelerationFactors•Accelerationfactorstakethefailuredistributionandmoveitparalleltotheoriginaldistribution.▪Achangeisslopetypicallyindicatesashiftinmechanism.•Typicallyitisusedtomovefailuredistributionsintotheregion(stressandsamplesize)ofinterest.815X

|©2 14MicronTechnology,Inc.|MicronConfidential9JEDECJESD218•FromJEDECJESD218,Section1:•"ThisstandarddefinesJEDECrequirementsforsolidstatedrives.Foreachdefinedclassofsolidstatedrive,thestandarddefinestheconditionsofuseandthecorrespondingenduranceverificationrequirements.Althoughenduranceistoberatedbaseduponthestandardconditionsofusefortheclass,thestandardalsosetsoutrequirementsforpossibleadditionaluseconditionsasagreedtobetweenmanufacturerandpurchaser.•Qualificationofasoli stat riv involv smanyfactorsb yon n uranc an r t ntion,sosuchqualificationisb yon th scop ofthisstan ar ,butthisstan ar issuffici ntforth n uranc an r t ntionpartofa riv qualification.Thisstandardappliestoindividualproductsandalsotoqualificationfamiliesasdefinedinthisstandard.•Thescopeofthisstandardincludessolidstatedrivesbasedonsolid-statenon-volatilememory(NVM).NANDFlashmemoryisthemostcommonformonmemoryusedinsolidstatedrivesatthetimeofthiswriting,andthisstandardemphasizescertainfeaturesofNAND.ThestandardisalsointendedtoapplytootherformsofNVM."August25,2 15

|©2 14MicronTechnology,Inc.|MicronConfidential10JESD218-Testing•JESD218,isreallyaboutvalidatingthatthedrivecanmeetitsendurancespecification,includingpostTBWdataretention.August25,2 15RDTTBWQual(JESD218)Cycle-to-DeathTesting

|©2 14MicronTechnology,Inc.|MicronConfidential11JESD218Requirements•ThegeneralrequirementsforanSSDareshownhere,asperJESD218.▪2Classesaredefined,ClientandEnterprise.August25,2 15

|©2 14MicronTechnology,Inc.12FunctionalFailureRate•FFRisdominatedbydefectivityrelatedissues.•Singlepages,wordlines,blockscanfailascanentiredie.▪Insomecasesfailurescanbegraceful,notresultingindataloss,othersarecatastrophic.P.Muroke,ProcIRPS,2 6

|©2 14MicronTechnology,Inc.|MicronConfidential13FunctionalFailureRate•Thesearetypicallythedefectrelatedfailures.▪DefectiveNAND,controllerfailuresetc...•ThisisrelatedtotheMTTF/AFRofthedrive.▪MostdrivesspecifytheAFR/MTTFofadrivethatmaynotalignwiththeJEDECspecification.•InmostcasesitisthepurposeoftheReliabilityDemonstrationTest(RDT)todemonstratetheMTTF.August25,2 15

|©2 14MicronTechnology,Inc.14FunctionalFailureRate-SampleSizeAugust25,2 15

|©2 14MicronTechnology,Inc.15FunctionalFailureRateandRDT•TheFFRatthemaxTBWgivesanestimateoftheaverageAFRovertheproductlifetime,butmaynotrepresentthefalloutinthefirstyear.▪Forapurelyexponentialdistribution,thenumberswillbethesame,however,inthenon-exponentialcaseitwillnotalign.August25,2 15JEDECRegionRDTRegion

|©2 14MicronTechnology,Inc.|MicronConfidential16UBER-UncorrectableBitErrorRate•FromJEDECJESD218August25,2 15

|©2 14MicronTechnology,Inc.17UBERandFailProbability•UBERisrelatedtothefailureprobabilityofacodeword.▪Thethirdpieceoftheequationbelowisessentiallyausagemodel.August25,2 15()()()()()111111__sec______sec______sec________sec____sec_+⋅⋅=""#$%%&'+⋅⋅=""#$%%&'+⋅⋅⋅⋅⋅⋅=""#$%%&'+⋅⋅⋅⋅⋅⋅=""#$%%&'+⋅=WANNNtFWANNNtFWANNNNNNNtFWANNNNNNNtFWANNNDRUBERcyclescwpertorscwperbitscodewordcyclescwperbitscwpertorscodewordcyclescwperbitsdrivespercodewordsdrivescwpertorsdrivepercodewordsdrivescodewordcyclescwperbitsdrivespercodewordsdrivescwpertorsdrivepercodewordsdrivescodewordcyclessampleinbitstorsfailingSSDInstantaneousUBERUsageModel

|©2 14MicronTechnology,Inc.18FlashMemoryReliability-UBERAugust25,2 15()()11__sec__+⋅⋅=WANNNtFDRUBERcyclescwpertorscwperbitscodewordSSD

|©2 14MicronTechnology,Inc.19UBERattheComponentvsDrive•ThedriveandcomponentUBERsmaynotbealignedforavarietyofreasons.▪TheusagemodelsthatfeedtheUBERcalculationsmaynotbealigned.▪Additionalerror-managementmaybepresentatthedrivelevel.▪RAID▪LDPCvsBCH▪DifferentECClevelsAugust25,2 15August25,2 15-2-1012345610-410-310-2Vt (V)ProbabilityL0L1L2L310-310-210-110-1610-1410-1210-1010-810-610-4RBERUBER HRER ≈ 3.0e-03HRER ≈ 3.0e-04NumberoferrorsinaCodewordCorrectionProbability 1BCHTypeCodesLDPCTypeCodesKhayat,P.R.et.al.,IMC,2 15

|©2 14MicronTechnology,Inc.20SampleSizeandUBERAugust25,2 15

|©2 14MicronTechnology,Inc.21HighTemperatureDataRetention•Shifts▪Detrappingofelectrons.▪Causestheentiredistributiontoshiftandwiden.▪Theshiftisoftheentirepopulation,theshiftbybitishighlyvariable.e-

e- e- e- e- e- e- e- e- e- e- e- e- e-

BeforeBakeVte-

e- e- e- e- e- e- e- e-

|©2 14MicronTechnology,Inc.22FlashMemoryReliability-HighTemperatureDataRetention•Highlytemperatureaccelerated.▪Eaof~1.1eV•Verysensitivetocyclingspeed.▪HigherspeedallowsforlessdetrappingbetweencyclesandmakesHTDRBworse.•Verysensitivetocyclingtemperature.▪HighertemperatureallowsmoredetrappingbetweencyclessoHTDRgetsbetterwithhighercyclingtemp.•HTDRissomewhatfielddependent.▪ThisimpliesL3willmovemorethanL2orL1,buttheimpactisnotnearlyasstrongasseeninroomtemperaturedataretention.N.Mielkeet.al.,Proc.44th

AnnualIRPS,2 6

|©2 14MicronTechnology,Inc.23DataRetentionCycTemp/Speed•ThephysicaleffectgoesbacktotheNANDhigh-temperaturedevicephysics.▪TheVtshiftisrelatedtodetrappingofelectronsfromthetunneloxide.•Ifthenumberoftrapsgeneratedisdependentprimarilyonelectronfluence,thenweneedtoonlycontroltrapoccupationdensityandensureitisequivalenttotheassumedfieldusagemodel.August25,2 15D v lopm nte-

e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e-

VtVtVtVte-

e- e- e- e- e- e- e- e- e- e- e- e- e- e- e-

|©2 14MicronTechnology,Inc.24FlashMemoryReliability-HighTemperatureDataRetention•Thecyclingtime/temperaturerelationshipassumesthattrapgenerationisessentiallytemperatureindependent,whileoccupancyisnot.•Inthatcase,thetotaltimeattemperatureduringcyclingdeterminestheoccupancy.▪Thegoalistogetthesameoccupancyunderacceleratedconditionsasunderusageconditions.▪ThetrapgenerationisthesamesincebothtargetthesamenumberofP/Ecycles(samefluencethroughthetox).•Forexample,assumepartsaretocycleinthefieldto5Kcyclesat55C24hrs/dayovera1yearperiod.•Iftheacceleratedtestwilloccurover5 hrs,theaccelerationfactorissimplytheratioofthetimes(365*24/5 =17.52).•UsingtheArrheniusequation,itispossibletocalculatethestresstemperaturerequiredtogetthislevelofdetrappingacceleration.August25,2 15CTTTTkEaAstressstressstressuse!81:Gives Tstressfor Solve15.273115.27355110617.81.1exp5002436511exp)detrap(5=!"#$%&''()**+,+-+⋅=⋅!"#$%&''()**+,-=-

|©2 14MicronTechnology,Inc.25SSDReliability-HighTemperatureDataRetention•Forhighlyacceleratedtesting(forexamplehighcyclingenterprisedrives),testingcanbedifficult.▪Forexample,foranenterprisedrivetobecycledin5 hoursorlessrequiresthetemperaturetobe>8 C.▪Thiscanbeanissueduetocomponenttemperaturelimitations,requiringlowertemperaturecycling.•Alsonotetheextremetemperaturesensitivity▪Thedifferencebetweencyclingover5 hoursandcyclingover4 hoursisonly2degrees.August25,2 15JEDECJESD218A

|©2 14MicronTechnology,Inc.26FlashMemoryReliability-HighTemperatureDataRetention•Itisimportanttonotethatthewidelyquoted1.1eVdoeshavesomeuncertaintyassociatedwithitispointedoutinJEDECJESD218:"AlthoughanSSDwouldbeexpectedtoreachitsTBWratingoveralifetimeofseveralyears,forthespecificpurposeofcalculatingTmaxthefullTBWisassumedtooccurwithinasingleyear.Thisisaconservativeassumptionbecauseashortertimeallowslessrelaxationbetweenwrites.Thisassumptionismadetoaddmarginagainstpossibleinaccuraciesinthe1.1eVaccelerationmodelforhightemperaturedataretention."JEDECJESD218

|©2 14MicronTechnology,Inc.27FlashMemoryReliability-DealingWithHTDR•Besidescontrollingusageconditions,insomecasesothertechniquesmaybeusedtominimizetheimpactofHTDR.•ThecaseshownheresuggestscompensatingfortheshiftbymovingtheVtdistributionsbackuptotheirinitialpositions.August25,2 15Y.Caiet.al.,ICCD,2 12

|©2 14MicronTechnology,Inc.28FlashMemoryReliability-LowTemperatureDataRetention•LeakageofelectronsfromtheFGthroughtrap-assisted-tunneling.▪ReferredtoasSILCorStress-Induced-Leakage-Currents.•Duringdataretentionthecellswilltendtomovetowardstheirlowestenergystate.▪Theexactsamemechanismisresponsibleforreaddisturb,buttendstogotheoppositedirection(chargegainvschargeloss).P.Cappellettiet.al.,2 4IEDM

|©2 14MicronTechnology,Inc.29FlashMemoryReliability-LowTemperatureDataRetention•VtTailFormation•Maindistributionremainsrelativelyunchanged.A.Hoefleret.al.,Proc.2 2IRPS,2 2

|©2 14MicronTechnology,Inc.30FlashMemoryReliability-LowTemperatureDataRetention•Besttotesttofailure,butmaybeimpractical.•Mayhavetoextrapolatetofailure.•Severalmodels.▪A.Hoefleret.al.,"StatisticalModelingoftheProgram/EraseCyclingAccelerationofLowTemperatureDataRetentioninFloatingGateNonvolatileMemories",Proc.IRPS,2 2▪H.Belgalet.al.,"ANewReliabilityModelforPost-CyclingChargeRetentionofFlashMemories",Proc.IRPS,2 2

|©2 14MicronTechnology,Inc.32FlashMemoryReliability-LowTemperatureDataRetention•LTDRisweaklytemperaturedependent(lowEa)•Stronglyfielddependent.▪VerysensitivetolevelwithhigherVt'smovingdownfaster.•Ingeneralextrapolationisrequiredtogetagoodestimateofthelifetime.•SimilartoHTDR,cyclingwilldegradeLTDR.H.Belgalet.al.,Proc.IRPS,2 2A.Hoefleret.al.,Proc.IRPS,2 2

|©2 14MicronTechnology,Inc.33LTDR-Extrapolation•Becauseofthelowactivationenergy,roomtemperaturedataretentiontypicallyrequiresextrapolation.•TheexampleshownhereusestheRBERtoextrapolatetoatargetvalue.▪Thetargetvalueshouldaccountforanynon-idealitiesinthepartotherwisetheestimateswillbeunrealistic.August25,2 15JEDECJESD218

|©2 14MicronTechnology,Inc.34UBEREventsvsFFREvents•Failsarenotcountedtwice.▪AdatalosseventcouldbeconsideredaUBEReventoranFFRevent.August25,2 157.1.2Cat gorizationoffailur sFailingSSDsaretobedividedintothreecategories:non-endurancefailures,endurancefunctionalfailures,andendurancedataerrors.Non-endurancefailuresaretobeexcludedfromconsiderationintheenduranceverificationbutmustofcoursebeconsideredifrelevanttootherpartsofdrivequalification.ThenumberoffunctionalfailuresistobeheldagainsttheFFRacceptancecriterion(equation2),andthenumberofdataerrorsistobeheldagainsttheUBERacceptancecriterion(equation3).Failuresaretobecategorizedasnon-endurancefailuresonlyifcompellingevidenceexiststhattheywerenotcausedbytheactofwritingthedrivetoitsendurancelimit,orbythesubsequentretentionstress.Failuresthatarenotinthecircuitpathofthewrittendata(forexample,failuresisolatedtopowersuppliesandcapacitors)maybeconsiderednon-endurancefailures.Failuresinthecircuitpathofthewrittendata,particularlythecontrollerandthenonvolatilememory,willmoreoftenbeconsideredendurancefailures,buttheremaybeexceptions.Failuresthatareinthecircuitpathofthewrittendatamaybeconsiderednon-endurancefailuresifthecauseofthefailurewereunrelatedtothequantityJEDECJESD218

|©2 14MicronTechnology,Inc.35WhatAboutEverythingElse?•JESD218providesagoodframeworkfordemonstratingthatanSSDmeetsitsdata-retentionrequirementsatthemaximumTBWrating.▪Thisisreallyjustatestofintrinsiccapabilityofthemedia.•Acomprehensivequalificationincludesmanyothertests,allofwhichcontributetotheunderstandingofthetotaldrivereliability.▪Anenterprisedrivemayhaveover1 componentsthatcouldcauseadrivetofailinthefield.August25,2 15ComprehensiveReliabilityPlanRDTOtherManufact.TestsOngoingTestingEndurance(JESD218)Mechanical4-CornersTest

|©2 14MicronTechnology,Inc.|MicronConfidential36CommentsonHistoricalHDDTesting•TestingforSSDsneedtobefocusedonSSDrelatedconcerns.•Teststhatarehistorical,butwerenotdevelopedforSSDsshouldbereviewedanddeterminediftheyapply.▪Theymayneedtobemodifiedorremovedinfavorofotherteststhatwillhelptrulyevaluatethequalityandreliabilityoftheproduct.▪Forexample,historical"altitude"testingforHDDsinvolveplacingtheHDDinalowpressurechamberduetoconcernsoftheheadnotbeingableto"float"abovethespinningmedia.▪Thisisagoodtestforthesetypesofmechanicalsystems,buthavenovalueonSSDs.•Resourcesandtimebetterspenttoinvestindevelopingnewtestandinvestinequipment/capabilitythatismeaningful.•AllSSDtesting/qualificationproceduresshouldbeunderconstantreviewtoensuretheproceduresevolveasrequired.August25,2 15

|©2 14MicronTechnology,Inc.37ReliabilityDemonstrationTest•ThepurposeofRDTistodemonstratethereliabilityoftheSSD.▪TypicallyspecifiedinMTTF.•Fixedsize/durationsampleplansfailtocomprehendthedifferenceinMTTFinmanycases.•Drivefamiliesshouldbedefinedinawaythatmakessense.August25,2 15

|©2 14MicronTechnology,Inc.|MicronConfidential38AccelerationFactors•Inordertosplitoutmechanisms,thedistributionsneedtoplottedonacommonaxis.•Thisrequiresapplicationoftheappropriateaccelerationfactors.•Accelerationfactorsareappliedbasedonthephysicsoffailure.•Startingpoint,generalrule-of-thumb▪NANDfailuresaretreatedas"TBWAccelerated"▪Hardwarefailuresaretreatedas"ThermallyAccelerated"▪Firmwarefailuresaretreatedasun-accelerated.August25,2 15

|©2 14MicronTechnology,Inc.|MicronConfidential39TBWAcceleration•IfNANDcyclingisexpectedtoaccelerateafailuremechanism,MicronusesaTBWaccelerationfactorwhenestimatingdrivelifetime.▪Theaccelerationfactorisbasedonthedatatransferrateintestversuswhatisexpectedinthefield.▪Althoughnotexplicitlycalledout,thisisembeddedintheJESD218methods•InsomecaseswewillgobeyondthespecifieddriveTBWinordertogetthebestfailuredistributions.▪Thetestsaredesignedtogeneratefailures(evenifthedrivemeetsspec),thisgivesbetterestimatesoftheAFR/MTTFaswellasvisibilityintofailuremechanismsaswellasreliabilitymargins.()()3210082.1175438002.1130:be ldfactor wouon accelerati the 5yrs,over 175TB of spec a with Hrs 1008in 130TB~ ing transferrdrive100G afor example,For 102210_/__/_12303012=⋅⋅⋅⋅=⋅⋅⋅⋅=⋅⋅⋅⋅=""#$%%&'⋅⋅⋅⋅⋅""#$%%&'⋅⋅⋅⋅==hrsTBhrsTBtWATBWtWATBWTBWAtWATBWtWATBWWATBWtDtDWATBWFieldHrCycNANDStressHrCycNANDTBWAstressfieldfieldfieldstressstressstressfieldfieldfieldstressstressfieldfieldfieldphysicalstressphysicalstressstress

|©2 14MicronTechnology,Inc.|MicronConfidential40ThermalAcceleration•Thermalaccelerationistypicallybasedonanactivationenergyof .7eV.•Theappropriateactivationenergydependsontheactualfailuremechanism,anddirectlymeasuredvalueswillgivethebestestimates.•Theliteratureandvariousspecificationscanalsoprovideguidance.FactoronAcceleratiTTkEkTEAkTEAttfttfaaaTT_11expexpexp212121=!"#$%&''()**+,-=''()**+,•''()**+,•=JEDECJEP122G

|©2 14MicronTechnology,Inc.|MicronConfidential41OtherAccelerationFactors•Accelerationfactorsforothertests(suchastempcycle,HASTetc...)shouldbereviewedtoensurethatthetestscanberelatedtofieldusageconditionsinordertoallowforriskanalysisaswellasensuringthetestsarealignedwithexpectations.D v lopm ntKuan-JungChunget.Al.,IMPACT,2 11

|©2 14MicronTechnology,Inc.42MechanicalTesting•TemperatureCycling▪Usedtoevaluatesolder-jointreliability.•HAST(HighlyAcceleratedStressTest)andTHP(TemperatureHumidityBias)▪Designedtoevaluatetheimpactofmoistureandtemperatureoncomponents.August25,2 15BabakArfaeiet.al.,ElectronicComp.&Tech.Conf.,2 14

|©2 14MicronTechnology,Inc.434-CornersTesting•4-Cornerstestingmeasuresthedrivecapabilityacrosstemperatureavoltagecorners.▪Shouldincludecross-temperaturereads.▪Normallytherearenooperationsduringthetemperaturetransitions.August25,2 15

|©2 14MicronTechnology,Inc.44OtherTests•Theremaybeadditionaltestsspecifictoparticularproductsormarkets.•Determiningmargintofailure,ratherthanpuresubstantiationtesting.August25,2 15

|©2 14MicronTechnology,Inc.45AdditionalTests•ManufacturingTests▪Examinationofmanufacturingtestsofmaterialgoingintoqualificationtests(andothertesting),isimportanttopickuplowerlevelissuesanddefectivitythatthelowersamplesizesofreliabilitytestingmaymiss.▪Burn-in(ifitexists)canprovideimportantinformationaboutunderlyingfailuredistributions.•OngoingTests▪Postqualificationitisimportanttomonitorthereliabilityofthesystemsinordertoensurethatitisnotshiftingdownoverthemanufacturinglifetime.August25,2 15

|©2 14MicronTechnology,Inc.46Comments/Conclusions•JESD218providesamethodforevaluatingenduranceunderspecificconditionsinauniformmanneracrosstheindustry.▪Thisisonly1portionofarobustqualificationstrategy.•SSDqualificationshouldincludeclear,statisticallymeaningfulteststhatcoverthelifetimeoftheproductunderrealisticconditions.▪SpecsbasedonHDDsmaynolongerbevalidduetowhattheyweremeanttodetectandshouldbereviewedwithacriticaleye.•ModelsaroundtestingconditionsneedtobeconstantlyevaluatedastheindustryseekstodesignSSDsclosertothemediacapability.August25,2 15

|©2 14MicronTechnology,Inc.47References•JEDECStandardJESD218A,"Solid-StateDrive(SSD)RequirementsandEnduranceTestMethod",September2 1 .•Muroke,P.,"FlashMemoryFieldFailureMechanisms",ReliabilityPhysicsSymposiumProceedings,2 6.•Khayat,P.R.,Kaynak,M.N.,Parthasarathy,S.,Tehrani,S.S.,"PerformanceCharacterizationofLDPCCodesforLarge-VolumeNANDFlashData",IEEEIMC,2 15.•Mielke,N.;Belgal,H.P.;Fazio,A.;Meng,Q.;Righos,N.,"RecoveryEffectsintheDistributedCyclingofFlashMemories",ReliabilityPhysicsSymposiumProceedings,2 6.•Cai,Yu;Yalcin,G.;Mutlu,O.;Haratsch,E.F.;Cristal,A.;Unsal,O.S.;KenMai,"Flashcorrect-and-refresh:Retention-awareerrormanagementforincreasedflashmemorylifetime",IEEE3 thInternationalConferenceonComputerDesign(ICCD),2 12.•Cappelletti,P.;Bez,R.;Modelli,A.;Visconti,A.,"Whatwehavelearnedonflashmemoryreliabilityinthelasttenyears",IEDMTechnicalDigest,2 4.•Hoefler,A.;Higman,J.M.;Harp,T.;Kuhn,P.J.,"Statisticalmodelingoftheprogram/erasecyclingaccelerationoflowtemperaturedataretentioninfloatinggatenonvolatilememories",ReliabilityPhysicsSymposiumProceedings,2 2.•Belgal,H.P.;Righos,N.;Kalastirsky,I.;Peterson,J.J.;Shiner,R.;Mielke,N.,"Anewreliabilitymodelforpost-cyclingchargeretentionofflashmemories",ReliabilityPhysicsSymposiumProceedings,2 2.•JEDECStandardJEP122G,"FailureMechanismsandModelsforSemiconductorDevices",October2 11•Kuan-JungChung;LiYuYang;Bing-YuWang;Chia-CheWu,"TheInvestigationofNodifiedNorris-LandzbergAccelerationModelsforReliabilityAssessmentofBallGridArrayPackages",5th

InternationalMicrosystemsPackagingAssemblyandCircuitsTechnologyConference(IMPACT),2 1 .•BabakArfaei;FrancisMutuku;KeithSweatman;Ning-ChengLee;EricCotts;RichardCoyle,"DependenceofSolderJointReliabilityonSolderVolumn,CompositionandPrintedCircuitBoardSurfaceFinish",ElectronicComponents&TechnologyConference,2 14.August25,2 15

quotesdbs_dbs17.pdfusesText_23

[PDF] [PDF] Practical Approach to Determining SSD Reliability - Flash Memory