HDD结构、工作原理、不良分析及HandlingGuide介绍.pdf
Page 1SAMSUNG CONFIDENTIALSamsung HDDPage 2SAMSUNG CONFIDENTIALContent:1.Basic HDD Understanding2.FA Decision Tree3.HDD HandlingPage 3SAMSUNG CONFIDENTIALBasic HDD UnderstandingPage 4SAMSUNG CONFIDENTIALMain Process Flowv 3.5Inch Main Process Flow(F1)Sub-AssySub-AssyTestTestHDA TestHDA TestOutgoingOutgoingPCBA MatePCBA MateCleaningCleaningAIR-Showering-Clamp-Spacer-Damper(1D Only)DI-Water-HSA,Media-Cover,Base(MBA)-VCM,Damper-Label,Filter-ScrewsBottom VCM InstallASTWASTWServo Track Write-Ammonite STWC/R AreaC/R AreaBackend AreaBackend Area-Ref.STW Verification Function TestPCBA Mate-Pad InsulatorServo CopyBurn-InHDD Final TestPackingPackingShippingOutgoing Inspection-OBA-ORTMain AssyMain AssyMedia,Spacer,Clamp Install in MBAHSA,VCM,FPC Install-Cover Screw Height Check-Imbalance testCover Install-Dynamic balancing test-HSA Height Check-Visual Inspection-Verify Drive Configuration-Label InstallAcceptance TestPage 5SAMSUNG CONFIDENTIALHDD OperationPage 6SAMSUNG CONFIDENTIALv Flash Memory:Storage firmware to control HDDv DRAM:Buffer between host and HDD which have different data processing ratev CPU Chip:Adapts the date from the controller to the specific host system bus used by the computerv Read/Write Channel:Detects bits in analog signal from the head and converts them into digital formv Combo IC:qPosition System:Keeps the heads positioned over the data on the diskqSPM Control:Keeps the disk rotating and at the proper speedHDD ArchitecturePage 7SAMSUNG CONFIDENTIALSpacer-diskABAPCBARecirculation FilterCover assemblyClamp-diskVCMMBAHSAInsulator-PCBDiskDisk-DamperSolid GasketDamper PlateTop coverTop Yoke ASM Head Stack ASM Disk Clamp Spacer Bottom Yoke ASM Latch Insulator PCB Ramp Base-Motor ASM 3.5”2.5”1.8”HDD StructurePage 8SAMSUNG CONFIDENTIALHead/Media InterfacingMediaHeadRamp L/UL(Load/UnLoad)rampCSS(Contact Start Stop)data zone Head&Media Interface Flying HeightWriting/ReadingAir flow10nmHDIpage/43 Page 9SAMSUNG CONFIDENTIALinput datadecodeduser dataEncoderHeaddiskwrite dataanalog read backDecoderDetectorWriting Process:User data Encoder Write data(current)Head Disk Reading Process:Disk Head Detector Decoder User data Read&Write ProcessPage 10SAMSUNG CONFIDENTIALMagnetization method in DiskNRZ:A direction of disk magnetization.NRZI:A transition or not(Voltage pulse or no pulse)11000111000010000101111N R Z IW R IT E N R ZM E D IAH E ADsignalcurrentThe top waveform shows how patterns are written to the disk.In the middle,a representation is shown of the way the media on the disk is magnetized into domains of opposite direction based on the polarity of the write current.The waveform on the bottom shows how the flux transitions on the disk translate into positive and negative voltage pulses when the disk is read.Read&Write ProcessPage 11SAMSUNG CONFIDENTIALso ft corecw ritereadshieldM Relem e ntm ed iawhen HHc.inductive write processHVHbV=IR R is dependant on H R=cos2(H),V(H)=IR(H)MR element should be biased to HbWriting/Reading in Head SidePage 12SAMSUNG CONFIDENTIALq Write:Writing record bit on the media magnetic layer.q Read:(G)MR sensor readsmagnetization bit transition.q Magneto-resistance:The phenomenon of resistancechanges by magnetic transition.q The basic MR head mechanism isbased on Ohms law;V=I RIllustration of magnetic recording processMagnetic Recording Head(MR/GMR)Magnetic Write/Read ConceptPage 13SAMSUNG CONFIDENTIAL1.Magnetization2.Magneto-ResistiveMagnetic Write/Read ConceptPage 14SAMSUNG CONFIDENTIALGeneral concepts behind the operation of an internal hard disk cacheTo support the sheer difference in the speeds of the HDD and InterfaceCache speed over 100times faster than data finding/reading from plattersFIFO data fetch method Write/Read Cache ConceptPage 15SAMSUNG CONFIDENTIALWhat Is Servo?What Is Servo?What Is Servo?v Feedback control system whose output is a MECHANICAL quantity such as position,velocity,or accelerationv What Does HDD Servo Do?a.Seeking to target trackb.Staying on(or following)the trackServo-DefinitionPage 16SAMSUNG CONFIDENTIALq Dedicated servo design One platter surface only contains servo information Data is written to other plattersq Embedded servo design All platter surfaces contain servo information and data Servo information is interspersed per each trackServo Design ConceptPage 17SAMSUNG CONFIDENTIAL SPM Control:Keeps the disk rotating and at the proper speed.SPM Control:Keeps the disk rotating and at the proper speed.Position system:Keeps the heads positioned on the R/W track.Position system:Keeps the heads positioned on the R/W track.Track:A strip of data written on a disk.Track:A strip of data written on a disk.Track density:The number of tracks per inch(unit:Track density:The number of tracks per inch(unit:tpitpi)Track width&Track pitch:width narrower than pitch Track width&Track pitch:width narrower than pitch(typically 80%,i(typically 80%,include guard band)nclude guard band)Crash stops:Limit the travel so that the heads do not come ofCrash stops:Limit the travel so that the heads do not come off the diskf the diskor hit the hub.or hit the hub.Disk area:Landing zone(=parking):inner guard band:data zoDisk area:Landing zone(=parking):inner guard band:data zone:ne:outer guard band.outer guard band.Servo Key TermsPage 18SAMSUNG CONFIDENTIAL Retract:The position system seek to the landing zone at the evRetract:The position system seek to the landing zone at the eventent(power fail/(power fail/cmdcmd)Actuator Lock:With no power,something must hold the actuatorActuator Lock:With no power,something must hold the actuatorin the land zone.in the land zone.Position transducer=Servo:Special magnetic patterns writtenPosition transducer=Servo:Special magnetic patterns written during during manufacturingmanufacturing-used by the position systems to determine location of the Head used by the position systems to determine location of the Head.Sample period(=1/sample rate):index time/servo sectors perSample period(=1/sample rate):index time/servo sectors per track track Seek time:The time it takes r/w head to move to specific dataSeek time:The time it takes r/w head to move to specific data track.track.The classThe class:One track/1/3 track/full track/:One track/1/3 track/full track/avgavg track seek time.track seek time.The modeThe mode:Acceleration:Acceleration-Coast Coast-Deceleration Deceleration-Settle Settle TMR(Track TMR(Track MisregistrationMisregistration):):-write to read TMR/write to read TMR/-write to write TMRwrite to write TMRServo Key TermsPage 19SAMSUNG CONFIDENTIALFA Decision TreePage 20SAMSUNG CONFIDENTIALVisual failNot detectionLow performanceNTF/CNDVisual inspectionFlash ROM&Ready CheckError CheckVisual O.K.Ready O.K.No ErrorVisual FailReady FailError DetectFA Flow ChartHDD errorBack Back NextNextPage 21SAMSUNG CONFIDENTIALVisual inspectionGet failed HDDGet failed HDDVisual inspectionDefine kinds of defect Define kinds of defect HDA visual defectHDA visual defectPCBA visual defectPCBA visual defectVisual inspectionVisual inspectionVisual FailPage 22SAMSUNG CONFIDENTIALNot detection errorQST TESTN/R dependantN/R dependantHeadHeadPassFailSpin up checkPassHOD checkX-rayPassFailN/R N/R dependantdependant HDAHDAPCBA SwapN/R dependant PCBAN/R dependant PCBAHDA dependantPCBA dependantMC CheckN/R dependantN/R dependantMC ErrorMC ErrorNo ErrorErrorGet failed HDDGet failed HDDPCBA SwapPCBA dependantHDA dependantN/R N/R dependant PCBAdependant PCBAN/R dependantN/R dependantHDAHDANot detection error Not detection error FailFlash Rom checkafter HAD swapNo spin HDDNo spin HDDCheck FAE FA report Page 23SAMSUNG CONFIDENTIALLow performanceGet failed HDDGet failed HDDVisual CheckReady CheckVisual O.K.Ready O.K.DATA Compare testDATA Compare testPES CheckPES CheckWrite/Read BER Write/Read BER Signal checkSignal checkTET TESTTET TESTPCBA Swap TestPCBA Swap TestHead errorHead errorDefect/ScratchDefect/ScratchPCBA errorPCBA errorHDAHDA errorerrorLow performance analysis Low performance analysis Define errorCNDCNDO.K.M/Cyl Log checkFlash CheckWhen Duplicated N/R errorWhen Duplicated N/R errorIn the special case,In the special case,Has same procedureHas same procedurewith not detection errorwith not detection errorO.K.N.G.N.G.Page 24SAMSUNG CONFIDENTIAL Visual inspection:Pass Drive ready check:Spin up&Ready well.MC area check:#5325 Some ECC error logged at SMART Error log&on the A-list.#0606 No error logged at SMART Error log&on the A-list.Data area scan:28pt ECC Errors were observed.After rewrite,error symptom has still not disappeared.(Hard defect)S/N:S1CKJ9BS205325,S1CKJ9AS300606FA FA E xampleE xamplerrHard defectHard defect by Hby HDI(DI(Head disk interference)Head disk interference)Page 25SAMSUNG CONFIDENTIAL MSL Results:Scratch damage was observed at error point.FA FA E xampleE xamplerrHard defect by HDIHard defect by HDI(Head disk interference)Head disk interference)The scratch,as shown above,is due to HDI.HDI scratch is caused by Unknown particles or head-disk touches(due to heads unstable flying)during operations.Page 26SAMSUNG CONFIDENTIALrrHead degradation by shockHead degradation by shockFA FA E xampleE xampleS/N:S1CKJ9AS300574 Visual inspection:Pass.Drive ready check:The drive showed Not ready symptom.(Clicking noise)HSA Status check(Quasi Static Test):Head#1 parameters showed abnormality.(Resistance,Pk-Pk Amplitude,Hysteresis value)Page 27SAMSUNG CONFIDENTIAL MSL Result:Head:HDI touch was observed on the slider.Disk:Static head slap was observed at CSS(Contact Start&Stop)zone.Static Head slap occurs when the drive is damaged by external shock during non-operation.Thus,this drive was damaged by external shock.And Head damage causes Not ready(noise sound)symptom.FA FA E xampleE xamplerrHead degradation by shockHead degradation by shock A head damage by external shock can be the root cause for not ready symptomPage 28SAMSUNG CONFIDENTIALHDD Handling GuidelinePage 29SAMSUNG CONFIDENTIAL29Page 30SAMSUNG CONFIDENTIAL30Page 31SAMSUNG CONFIDENTIAL31Samsung Hard Disk Drives(HDD)travela great distance from Gumi(Korea)They travel in specially designedpackaging that protects them againstany possible rough handling conditions.HDDs are vulnerable to damage when not protected!(e.g.any process where the drive isHANDLED or MOVED)Key areas for inducing damage areWarehouse,Kitting,AssemblyPage 32SAMSUNG CONFIDENTIAL32 MAJORITY of damage is done before the drive reaches test!This costs time and money!Page 33SAMSUNG CONFIDENTIAL33vv Hard Disk Drives are DEHard Disk Drives are DELICATELICATEvv Hard Disk Drives are Hard Disk Drives are EASILY DAMAGEDEASILY DAMAGEDPage 34SAMSUNG CONFIDENTIAL34vv Take Great Care whenTake Great Care whenhandling handling Hard Disk DrivesHard Disk DrivesMishandling Costs.MoneyLost Production TimeExtra workPage 35SAMSUNG CONFIDENTIAL35vv EVERYBODY MUST follow Proper Handling EVERYBODY MUST follow Proper Handling Procedures at ALL TIMESProcedures at ALL TIMESvv DonDon t t SHOCKSHOCK Hard Disk DrivesHard Disk Drivesvv DO protect Hard Disk DrivesDO protect Hard Disk Drives against Electro against Electro Static DischargeStatic Discharge ESDESDvv NEVER DROPNEVER DROP Hard Disk DrivesHard Disk DrivesPage 36SAMSUNG CONFIDENTIAL36SmokeParticleHumanHairDust ParticleFingerprintFlyingHeightDisk Disk Read/WriteHeadPage 37SAMSUNG CONFIDENTIAL37 Drive base damagePage 38SAMSUNG CONFIDENTIAL38vv GOOD HDDGOOD HDDvv DAMAGED HDDDAMAGED HDDCan you Spot the Difference?Can you Spot the Difference?You cant always tell by lookingPage 39SAMSUNG CONFIDENTIAL39Page 40SAMSUNG CONFIDENTIAL40 Disk damage due to shockPage 41SAMSUNG CONFIDENTIAL41 Shock that can damage Hard Disk DrivesHDD Drop HeightMaterial 2.5 cm drop on to a hard surface(bench or chassis)can cause damage!Page 42SAMSUNG CONFIDENTIAL42 Shock that can damage Hard Disk DrivesHDD Material 2.5 cm drop on to a hard surface(bench or chassis)can cause damage!Page 43SAMSUNG CONFIDENTIAL43Page 44SAMSUNG CONFIDENTIAL44DO Take Extra Care when movingHard Drive Pallets Inspect Pallets and Report Damage(this prevents damaged HDDs being issued to line)Transport Drives in APPROVED PACKAGING(this protects the fragile contents)Be gentle with HDD pallets and boxes(easily damaged)Page 45SAMSUNG CONFIDENTIAL45DO NOT.Stack more than 2 pallets(pallet specification)Move unbound pallets(boxes can fall)Drop pallets or boxes(fragile contents)Damage boxes(fragile contents)Page 46SAMSUNG CONFIDENTIAL46Store Upright FragileStacking Height Protected StorageMust follow storage and handling instructionsLook familiar?Page 47SAMSUNG CONFIDENTIAL47These processes handle unprotected HDDs The slightest SHORT shock can cause damage(drive to drive or drive to metal)Page 48SAMSUNG CONFIDENTIAL48DO Take Care Be gentle with Hard DrivesWork with approved work benches Use ESD protection Handle drives by edge Handle one drive at a time Keep area tidy Allow drive to power downbefore moving it Remove drive if dropped or mishandledPage 49SAMSUNG CONFIDENTIAL49DO NOT.Stack drives Stand drives on edge Knock drives together Put drives on hard surfaces Drop drives Touch PCB Assembly Use drive if dropped or mishandled Move drive until 10 secondsafter power is removedPage 50SAMSUNG CONFIDENTIAL50Samsung HDD Handling GuidePage 51SAMSUNG CONFIDENTIAL51DO Take Care Be gentle when fitting screws.Be gentle when assemblinginto chassis Handle drives by edgePage 52SAMSUNG CONFIDENTIAL52DO NOT.Force drives into chassis Knock drives together Drop drives Touch PCB AssemblyPC chassisPage 53SAMSUNG CONFIDENTIAL53Page 54SAMSUNG CONFIDENTIAL54 DO.Treat Test Failures as GOOD drives Follow good handling proceduresfor test failures Take care when removing drive fromchassis Store test failures in ESD bags Store test failures in approved HDDpackaging Remember,bad handling can hide original failure reasonPage 55SAMSUNG CONFIDENTIAL55Page 56SAMSUNG CONFIDENTIAL56 Have a clean and tidy work area Only essential items in work area Use ESD approved Garments ALL materials should be ESD safe ESD protection must be used ESD equipment should be checked ESD labels and signs must be displayed No HARD SURFACES Work areas should have ESD foam protectionwith ESD mats Test racks should be secure Floors should be clear of any obstructions(cables,debris etc)Page 57SAMSUNG CONFIDENTIAL57Page 58SAMSUNG CONFIDENTIALHDD Package Damage GuidelinePage 59SAMSUNG CONFIDENTIAL59Compressed BoxChange the boxHDD UAI(Use As Is)Page 60SAMSUNG CONFIDENTIAL60Compressed on the Bottom Surface of BoxChange the boxHDD UAI(Use As Is)Page 61SAMSUNG CONFIDENTIAL61Dent on the surface of boxChange the boxHDD UAI(Use As Is)Page 62SAMSUNG CONFIDENTIAL62Peel off on the surface of boxChange the boxHDD UAI(Use As Is)Page 63SAMSUNG CONFIDENTIAL63Hole on the surface of boxHDD Baseline testChange the box and UAI the HDDdependent on the baseline resultPage 64SAMSUNG CONFIDENTIAL64Falling PalletChange the palletChange the lowest box after visual inspectionIf the box is punctured perform HDD baseline test and dispose HDD according to the resultPage 65SAMS
