HDD Failures and Handling

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HDD Failures and Handling. School of Mechanical Engineering Institute of Engineering Suranaree University of Technology. Measurement and Test requirements. Disc Balance Acoustic Leak test NRRO & RRO Track registration. Measurement and Test requirements. - PowerPoint PPT Presentation


  • HDD Failures and HandlingSchool of Mechanical EngineeringInstitute of EngineeringSuranaree University of Technology

  • Measurement and Test requirementsDisc BalanceAcousticLeak testNRRO & RROTrack registration

  • Measurement and Test requirements shock, vibration, temperature, humidity, altitude magnetic field ESDBreathing hole top cover

  • Measurement and Test requirements() Interface SATAPower-off sequence Required power-off sequence.

  • Measurement and Test requirementsDisc BalanceAcousticLeak testNRRO & RROTrack registration

  • Disk BalanceA disk drive recording device comprises at least two platters for storing magnetic recording data and a spindle motor rotating at high speed for mounting the platters.

  • Disk BalanceThe disk drive is assembled by using pushing devices to push the platters toward the center of the spindle motor in respective directions to bring a portion of an inside circumference of a concentric center hole of each of the platters in contact with an outer circumference of the spindle motor so that the center of gravity of each platter coincides with a center axis of the spindle motor.

  • Disk BalanceMethod for balancing a rotating assembly using eccentric rings (United States Patent 6947253)

  • Measurement and Test requirementsDisc BalanceAcousticLeak testNRRO & RROTrack registration

  • AcousticSound power levelMeasurements are to be taken in accordance with ISO 7779.The mean of the sample of 40 drives is to be less than the typical value.Each drive is to be less than the maximum value.

  • AcousticThesound powerin dB converted from Watts as follows: Ten times the common logarithm of the ratio of the acoustic power to the reference sound power, 10-12 W or 1 pW.

    The symbol is LW

  • AcousticThe criteria of A-weighted sound power level are described below.

  • AcousticThe background power levels are to be recorded.Sound power tests are to be conducted with the drive supported by spacers so that the lower surface of the drive be located 253 mm above from the chamber floor. No sound absorbing material shall be used.

  • AcousticThe acoustical characteristics of the disk drive are measured under the following conditions.Idle mode - Power on, disks spinning, track following, unit ready to receive and respond to control line commands.Operating mode - Continuous random cylinder selection and seek operation of actuator with a dwell time at each cylinder.

  • Measurement and Test requirementsDisc BalanceAcousticLeak testNRRO & RROTrack registration

  • Leak TestIt is air leak test when air pressure is applied into the HDD cavity. It indicate HDD seal performance.

  • Measurement and Test requirementsDisc BalanceAcousticLeak testNRRO & RROTrack registration

  • NRRO & RRONon-repeatable Run-out (NRRO) is one of the main sources of Track Mis-Registration (TMR) which prevents high track density.

  • NRRO & RROIt is reported that NRRO is mainly generated by the defect frequencies of ball bearing.Minimizing NRRO, lowering acoustical noise, and improving reliability.There is an upper limit at which the Ball Bearing design can no longer overcome the NRRO problem at the higher areal densities.Currently with Ball Bearings, NRRO has settled in the 0.1 micro-inch range.

  • NRRO & RROFluid Dynamic Bearing (FDB) motors generates less NRRO due to the higher viscosity of lubrication oil between the sleeve and stator.

  • NRRO & RROFDB design higher dampingreduced frequency resonancebetter non-operational shock resistancegreater speed controlimproved acoustics.

  • NRRO & RROError Types: NRRO (Non-Repeatable Run-Out)External shock and vibration (other spindles)Spindle bearing runout (periodic but not synchronous)Air turbulence: disk vibration/flutter, actuator windageActuator pivot and flex cable bias (nonlinear)

  • NRRO & RROError Types: RRO (Repeatable Run-Out)Synchronized to spindle rotationDisk slip, thermal motion, drive induced vibration, STW NRROCompensation techniques (include peak filter and feed forward)

  • Measurement and Test requirementsDisc BalanceAcousticLeak testNRRO & RROTrack registration

  • Track registrationDisk Transfer Rate:

    The test defines the linear reading speed in thousand bytes/sec. In the end, the test gives two numerical values - speed in the beginning and in the end of the disc.

  • Track registrationDisk Access Time:The test defines an access time in ms. The final value is equal to the sum of average latency and average seek time.Disk CPU Utilization:The test shows the CPU utilization in percents in the course of data exchange with a disc.

  • FailuresFailuresMedia FailuresHead FailuresHead-Media Spacing / Fly HeightPCBA FailuresMechanical FailuresThermal Asperity (TA)Off Track Read/Write

  • Media Failurethe platters and the magnetic media, servo operation and the like. read or write errors, poor handling, scratches on the media surface, errors in low-level formatting, etc.

  • Head and Head Assembly Failuresimproper flying height, head contamination, defects in head manufacture, bad wiring between the heads and the logic board

  • Head-Media Spacing / Fly HeightThere are many ways that hard disk can failThe most famous way is Head crashHead crashes is are the "airline disasters" of the hard disk world but actually responsible for a small percentage of total drive problems

  • Head crashes on HDD

    Above: A severe headcrash on a SCSI hard disk

  • Head crashes on HDDCause: dust or contamination sudden jolt or shock.Recovery Possibilities: Most of head crash are completely unrecoverable some head crashes are mild and most of the data can be recovered.

  • Logic Board or Firmware Failuresrelated to the drive's integrated logic board, its chips and other components, and the software routines (firmware) that runs it.

  • Mechanical Failuresthe spindle motor or bearings, motor burnout, "stuck" bearings, excessive heat,excessive noise and vibration.Actuator problems

  • Thermal asperity (TA)Definition: A TA is a read signal spike caused by sensor temperature rise due to contact with disk asperities or contaminant particles. Cause: TAs may cause GMR or MR heads to temporarily lose their reading capability, and may potentially damage the transducer.

  • Track average amplitude (TAA)Definition: the average peak-to-peak value of the data over a specified range of sectorsDepends on the density of the drives platter the sensitivity of the read-channel. If the TAA is too high, the magnetic flux from the platter will cause the MR head to saturate, which distorts the waveform that the head sends to the preamp. If the TAA is too low, causing random bit errors.

  • Clean room's critical controlESD controlContamination control

  • Electrostatic Discharge (ESD)Electrostatic discharge (ESD) is the sudden and momentary electric current that flows between two objects at different electrical potentials (such as ground). The term is usually used in the electronics and other industries to describe momentary unwanted currents that may cause damage to electronic equipment.

  • Type of ESD DamageUpset FailureCatastrophic Failure

  • Upset Failure Upset failures occur when an electrostatic discharge has caused a current flow that is not significant enough to cause total failure, but in use may intermittently result in gate leakage causing software malfunction or incorrect storage of information.

  • Catastrophic FailureDirect catastrophic failures occur when a component is damaged to the point where it no longer functions correctly. Latent catastrophic failures occur when ESD weakens a component to the point where it still functions correctly during testing, but subsequent minor electrical overstresses or power surges during normal operation of the equipment cause the component to fail.

  • ESD Test ModelsHuman-Body Model (HBM)Machine Model (MM)Charged-Device Model(CDM)

  • Human-Body Model (HBM)The HBM was developed to simulate the action of a human body discharging accumulated static charge through a device to ground, and employs a series RC network consisting of a 100-pF capacitor and a 1500- resistor.

  • Machine Model (MM)The MM simulates a machine discharging accumulated static charge through a device to ground. It comprises a series RC network of a 200-pF capacitor, and nominal series resistance of less than 1 ohm. The output waveform usually is described in terms of peak current and oscillating frequency for a given discharge voltage.

  • Charged-Device Model(CDM)The CDM simulates charging/discharging events that occur in production equipment and processes. Potential for CDM ESD events occur when there is metal-to-metal contact in manufacturing.

  • Controlling ESDDissipate and GroundingIsolationPrevention

  • Dissipate and Grounding Grounding is a means of draining the static charges present on your body, by use of a personal grounding device or a wrist strap.

    Human SuitMachineToolsWorking Area

  • IsolationIsolation can also be accomplished by keeping charge generating materials away from working areaplastic bagscellophane tapepaper workcommon untreated plastic materialsstyrofoam cups

  • Isolationduring storage and transportationpacking of components and assemblies to protect static charges cannot penetrate containers made of conductive materials or have a conductive layer.

  • Prevention of ESDNever enter an ESD-sensitive area without taking the proper precautions.Test ground devices for correct operation on a daily basis.Open ESD-sensitive items only at a static-safe workstation.Always keep your workstation clean and clear of unnecessary material, particularly common plastics.

  • Prevention of ESDPlace ESD-sensitive items on a dissipative surface, not on top of a blueprint or other paperwork.Return ESD-sensitive items to their ESD-protective containers when not actively working with the items.Do not hold ESD-sensitive items against your clothing. Even if you are wearing a wrist strap, your body is grounded but your clothes are not!

  • ESD EnvironmentTemperature 19-25 CRelative humidity 40-60%Dust (Cleanroom Technology)

  • Contaminations HDD

  • What is ContaminationContamination /

    Quality, Reliability, Yield, Cost


  • Silicon oxide, Silicon carbide, Aluminum oxide,

  • () Slider Platter Slider Platter

  • (Hard Particle)

  • Particulate Contamination Contamination Contamination (ESD) 2

  • Surface finishing of component or machine (Electroless Nickel plating), (chloride), sulfate, phosphate and other --> corrosion Slider Slider Platter Slider

  • HDD (Hard-disk interface, HDI) Silicone, Dissolved organic phosphorus (DOP), Surfactant, Plasticizer, Outgases material from heating plastic, Adhesives

  • Strontium (Sr), Samarium (Sm), , Neodymium (Nd)


  • (Read/Write head)

  • ManMaterialsMachineProcessesEnvironmentContamination SourceParticleIonicOrganicMagneticWaveContaminationDefectFailureWearCrashError

  • Man / (Sensible heat) (Latent heat)

  • Contamination , , Cleanroom Particulate ContaminationMan

  • 0.3

  • Molecular Contamination contam Chloride Man

  • Silicones Molecular ContaminationMan

  • Man

  • Silicone Man

  • Particle 30-40 Particle 40,000-50,000Man

  • Molecular Contamination Bacteria Mouth CoverMan

  • Man

  • Man

  • Mouth Cover Man

  • / Man

  • Materials Surfactant Outgases material adhesive VCM

  • Cleanroom Materials

  • Cleanroom (AIO)Materials

  • Machine/Processes

  • Machine/Processes

  • Environment (External) (Organic Compound) (Ironic Compound)

  • Environment (Internal)

  • / Sillicon Oxide/ Sillicon Carbide Hard Particle Out gassing Sillicon Environment (Internal)

  • MaterialsAcrylates()SiliconeDOPSulfur compoundChloridesSulfateSilicon oxide, Silicon carbideAluminum oxideTitanium carbideTitanium nitrideSr, NdSources (Adhesives) (Lotion, lipstick)(Plasticizers), plastic containersGloves, rubber, (passivate steels)Human, bagFracture on suspension (FOS) cover coatSand, sand paper, cement (Polishing material) (Ceramic tweezers) (Clip ring) Voice coil motor (VCM), hand tools

  • HDD Platter HDD (Cleanroom)

  • (Cleanroom) Federal Standard 209E 1 (Airborne Particles) ISO 14644-1

  • (Cleanroom) : (Air flow pattern)

  • (Airborne Particles)

  • (Airborne Particles) 0.5 m 10 1000 1 m3 0.3 m 105 /

  • Federal Standard 209E Airborne Particulate Cleanliness Classes (1992)

  • 72 oF (22.2 oC) 0.25 oF (0.14 oC)

  • 40-60 %RH

  • (positive pressure) (air shower) 0.05

  • 1,080 1,620 lux

  • Conventional Flow CleanroomUnidirectional Flow CleanroomMixed Flow CleanroomIsolated Flow Cleanroom Cross Flow Cleanroom

  • Conventional Flow Cleanroom Design Design Cleanroom Class 10,000 1,000

    High Efficiency Air Filter


    Air Extract

  • Unidirectional Flow Cleanroom Design Design Cleanroom Class 100

    High Efficiency Air Filters


    Air Extract

  • Mixed Flow Cleanroom

    High Efficiency Air Filter


    Air Extract

  • Mixed Flow Cleanroom

  • Isolated Flow Cleanroom

    High Efficiency Air Filter


    Air Extract

  • Cross Flow Cleanroom

  • Electrostatic charge

  • Air Filter ()Air Shower ()Air Lock ()Passing-Thru Box ()Laminar Flow Product ()Air Return ()Cleanroom Apparel ()Minienvironment

  • Air FilterHEPA Filter (High Efficiency Particulate Air Filter)VEPA Filter (Very High Efficiency Particulate Air Filter)ULPA Filter (Ultra Low Penetration Air Filter)

  • HEPA Filter 0.3 m 99.97% DOP (Di-octylphthalata Test) Pressure Drop 25.4 mm.Hg Rated Airflow Capacity 0.3 m 3 10,000 Filter

  • VEPA Filter 0.3 m 99.9997% DOP Pressure Drop 25.4 mm.Hg Rated Airflow Capacity 0.3 m 3 1,000,000 Filter

  • ULPA Filter 0.3 m 99.9999% DOP Pressure Drop 25.4 mm.Hg Rated Airflow Capacity 0.3 m 1,000,000 Filter

  • Air Shower

  • Air Lock

  • Passing-Thru Box

  • Vertical and Horizontal Laminar Benches

  • Cleanroom Apparel

  • Cleanroom Apparel

  • Cleanroom Apparel (Class 10,000)Shoe CoversLaboratory CoatHair NetSafety GlassesClean Room GlovesPutting OnTaking Off

  • Cleanroom Apparel (Class 100)Shoe CoversHair NetGowningBunny SuitBootiesHoodNose/Mouth MaskSafety GlassesClean Room GlovesFace ShieldRespiratorPutting OnTaking OffOutside Clean RoomFor Handling Wafers

  • Clean Room Dos and DontsDont !touch your face or skin with gloves touch building hardware, oily machinery, or wafer loading areas lean on equipment wear cosmetics, powders, or colognes wear anything on fingers-- remove all rings and bracelets use paper, pencils or markers that leave dust or lint

  • Clean Room Dos and DontsDo:change gloves whenever they get dirty or tornuse a fresh pair of gloves whenever handling wafers wipe down wafer handling areas with isopropanol use clean room paper and dust-free ball point pens

  • HDD HandlingHard disk drives (HDD) can be critically damaged by static electricity, shock, vibration and other factors. Therefore, the proper handling of HDD in appropriate environment to ensure their reliability is important.General instructionsHandling of the packageStorage and handling after unpackingAssembly and testing

  • General instructionsWear a wrist strap when handling HDDPlaces HDD on a static-free place

  • General instructionsDo not carry two or more HDD with one stacked on top of anotherDo not leave HDD in a vertical position wit...


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