HDD结构、工作原理、不良分析及HandlingGuide介绍

Page1SAMSUNGCONFIDENTIALSamsungHDDPage2SAMSUNGCONFIDENTIALContent:1.BasicHDDUnderstanding2.FADecisionTree3.HDDHandlingPage3SAMSUNGCONFIDENTIALBasicHDDUnderstandingPage4SAMSUNGCONFIDENTIALMainProcessFlowv3.5InchMainProcessFlow(F1)Sub-Ass’ySub-Ass’yTestTestHDATestHDATestOutgoingOutgoingPCBAMatePCBAMateCleaningCleaningAIR-Showering-Clamp-Spacer-Damper(1DOnly)DI-Water-HSA,Media-Cover,Base(MBA)-VCM,Damper-Label,Filter-ScrewsBottomVCMInstallASTWASTWServoTrackWrite-AmmoniteSTWC/RAreaC/RAreaBackendAreaBackendArea-Ref.STWVerificationFunctionTestPCBAMate-PadInsulatorServoCopyBurn-InHDDFinalTestPackingPackingShippingOutgoingInspection-OBA-ORTMainAss’yMainAss’yMedia,Spacer,ClampInstallinMBAHSA,VCM,FPCInstall-CoverScrewHeightCheck-ImbalancetestCoverInstall-Dynamicbalancingtest-HSAHeightCheck-VisualInspection-VerifyDriveConfiguration-LabelInstallAcceptanceTestPage5SAMSUNGCONFIDENTIALHDDOperationPage6SAMSUNGCONFIDENTIALvFlashMemory:StoragefirmwaretocontrolHDDvDRAM:BufferbetweenhostandHDDwhichhavedifferentdataprocessingratevCPUChip:AdaptsthedatefromthecontrollertothespecifichostsystembususedbythecomputervRead/WriteChannel:DetectsbitsinanalogsignalfromtheheadandconvertsthemintodigitalformvComboIC:qPositionSystem:KeepstheheadspositionedoverthedataonthediskqSPMControl:KeepsthediskrotatingandattheproperspeedHDDArchitecturePage7SAMSUNGCONFIDENTIALSpacer-diskABAPCBARecirculationFilterCoverassemblyClamp-diskVCMMBAHSAInsulator-PCBDiskDisk-DamperSolidGasketDamperPlateTopcoverTopYokeASMHeadStackASMDiskClampSpacerBottomYokeASMLatchInsulatorPCBRampBase-MotorASM3.5”2.5”1.8”HDDStructurePage8SAMSUNGCONFIDENTIALHead/MediaInterfacingMediaHeadRampL/UL(Load/UnLoad)rampCSS(ContactStartStop)datazone[Head&MediaInterface]FlyingHeightWriting/ReadingAirflow10nmHDIpage/43Page9SAMSUNGCONFIDENTIALinputdatadecodeduserdataEncoderHeaddiskwritedataanalogreadbackDecoderDetectorWritingProcess:Userdata→Encoder→Writedata(current)→Head→DiskReadingProcess:Disk→Head→Detector→Decoder→UserdataRead&WriteProcessPage10SAMSUNGCONFIDENTIALMagnetizationmethodinDiskNRZ:Adirectionofdiskmagnetization.NRZI:Atransitionornot(Voltagepulseornopulse)11000111000010000101111NRZIWRITE전류NRZMEDIAHEADsignalcurrentIdealizeddepictionofthewayharddiskdataiswrittenandthenread•Thetopwaveformshowshowpatternsarewrittentothedisk.•Inthemiddle,arepresentationisshownofthewaythemediaonthediskismagnetizedintodomainsofoppositedirectionbasedonthepolarityofthewritecurrent.•Thewaveformonthebottomshowshowthefluxtransitionsonthedisktranslateintopositiveandnegativevoltagepulseswhenthediskisread.Read&WriteProcessPage11SAMSUNGCONFIDENTIALsoftcoreΦcwritereadshieldMRelementmediawhenHHc.inductivewriteprocessHVHbV=IRRisdependantonHR=cos2(H),V(H)=IR(H)MRelementshouldbebiasedtoHbWriting/ReadinginHeadSidePage12SAMSUNGCONFIDENTIALqWrite:Writingrecordbitonthemediamagneticlayer.qRead:(G)MRsensorreadsmagnetizationbittransition.qMagneto-resistance:Thephenomenonofresistancechangesbymagnetictransition.qThebasicMRheadmechanismisbasedonOhm’slaw;ΔV=IΔRIllustrationofmagneticrecordingprocessMagneticRecordingHead(MR/GMR)MagneticWrite/ReadConceptPage13SAMSUNGCONFIDENTIAL1.Magnetization2.Magneto-ResistiveMagneticWrite/ReadConceptPage14SAMSUNGCONFIDENTIAL•Generalconceptsbehindtheoperationofaninternalharddiskcache•TosupportthesheerdifferenceinthespeedsoftheHDDandInterface•Cachespeedover100timesfasterthandatafinding/readingfromplatters•FIFOdatafetchmethodWrite/ReadCacheConceptPage15SAMSUNGCONFIDENTIALWhatIsServo?WhatIsServo?WhatIsServo?vFeedbackcontrolsystemwhoseoutputisaMECHANICALquantitysuchasposition,velocity,oraccelerationvWhatDoesHDDServoDo?a.Seekingtotargettrackb.Stayingon(orfollowing)thetrackServo-DefinitionPage16SAMSUNGCONFIDENTIALqDedicatedservodesignØOneplattersurfaceonlycontainsservoinformationØDataiswrittentootherplattersqEmbeddedservodesignØAllplattersurfacescontainservoinformationanddataØServoinformationisinterspersedpereachtrackServo–DesignConceptPage17SAMSUNGCONFIDENTIALüüSPMControl:Keepsthediskrotatingandattheproperspeed.SPMControl:Keepsthediskrotatingandattheproperspeed.üüPositionsystem:KeepstheheadspositionedontheR/Wtrack.Positionsystem:KeepstheheadspositionedontheR/Wtrack.üüTrack:Astripofdatawrittenonadisk.Track:Astripofdatawrittenonadisk.üüTrackdensity:Thenumberoftracksperinch(unit:Trackdensity:Thenumberoftracksperinch(unit:tpitpi))üüTrackwidth&Trackpitch:widthnarrowerthanpitchTrackwidth&Trackpitch:widthnarrowerthanpitch(typically80%,i(typically80%,includeguardband)ncludeguardband)üüCrashstops:LimitthetravelsothattheheadsdonotcomeofCrashstops:Limitthetravelsothattheheadsdonotcomeoffthediskfthediskorhitthehub.orhitthehub.üüDiskarea:Landingzone(=parking):innerguardband:datazoDiskarea:Landingzone(=parking):innerguardband:datazone:ne:outerguardband.outerguardband.Servo–KeyTermsPage18SAMSUNGCONFIDENTIALüüRetract:ThepositionsystemseektothelandingzoneattheevRetract:Thepositionsystemseektothelandingzoneattheeventent(powerfail/(powerfail/cmdcmd))üüActuatorLock:Withnopower,somethingmustholdtheactuatorActuatorLock:Wit