Western Digital Technologies, Inc.

Joseph M Viglione

Raffi Codilian

Mostafa Pakzad

Peter Cheok Him Pang

Mohammad R Bahadori

Roma Leang

Keith R Berding

Chun Sei Tsai

Carl E Barlow

Charles D Flanigan

Walter W Butler

Sang Huynh

William D Johns

Minh N Trinh

Suleyman Attila Yolar

Ronald L Nelson

James M Mang

Peter H Dinh

Yvonne M Utzig

Boon Nee Yang

Nevin A Archibald

Tariq Iqbal

A storage device comprising a storage media and a controller is disclosed. The controller is configured to receive access commands from a host, to write data to or read data from the storage media based on the access commands, to detect a trigger event, and, when the trigger event is detected, to throttle back the access commands from the host based on an amount of data in a cache.

Throttled command completion time

Disclosed is a system and method for disk drive grouping in a multi-cell disk drive test system. A test platform includes a plurality of cells. Each cell is configured to receive and to provide communication with a disk drive. An automated loader/unloader is coupled to a test computer and is responsive to the test computer. The automated loader/unloader is configured to identify disk drives and to selectively load and unload disk drives into and out of the plurality of cells. Particularly, once the automated loader/unloader has identified a first disk drive, the test computer is configured to: determine a grouping criteria based upon the first disk drive; detect a subsequent disk drive having the same grouping criteria as the first disk drive; and cause the automated loader/unloader to load the subsequent disk drive into one of the plurality of cells.

Disk drive grouping in a multi-cell disk drive test system

A multi-cell disk drive test system that provides for asynchronous software module updates that includes a test platform, one or more test manager computers (TMCs), and a test coordinator computer (TCC). The test platform includes a plurality of cells in which each cell is configured to receive and to provide communication with a disk drive. The TCC is configured to communicate with one or more TMCs and to store a plurality of updated software module versions. After a disk drive is determined to be in an appropriate cell, the TMC: determines a test step to be performed on the disk drive and a cell software module currently stored for the cell; determines if an updated software module version associated with the test step is stored on the TCC, and if so, downloads the updated software module version, and updates the TMC with the updated cell software module version.

Asynchronous automatic software module updates in a multi-cell disk drive test system

Disclosed is a system and method for particle monitoring for a head disk assembly (HDA) to detect a head disk interface (HDI) event. A particle monitoring system includes a particle detector, an air sampling device, and a computer. The air sampling device is coupled to and in fluid communication with the particle detector. The air sampling device extends into the HDA to obtain an air sample. The particle detector is used to detect particles contained in the air sample. The computer is coupled to the particle detector and is configured to: monitor the particles detected by the particle detector; and declare an HDI event if the particles detected in the air sample match a pre-defined characteristic.

System and method for particle monitoring for a head disk assembly to detect a head disk interface event

Disclosed are techniques related to cluster-based defect detection testing for disk drives. A disk drive comprises a disk, a moveable head to scan the tracks of the disk, and a defect detection circuit to detect defects on the disk scanned by the moveable head. The disk drive includes a microprocessor for controlling operations in the disk drive including cluster-based defect detection. The microprocessor under the control of a cluster detection program defines a scan window. The scan window corresponds to an area of the disk scanned by the moveable head. The microprocessor under the control of the cluster detection program further defines a cluster threshold corresponding to a minimum number of defects required to occur within the scan window and identifies a defect cluster if a cluster threshold of defects occurs within the scan window. By identifying defect clusters on the disk these defect clusters can be margined.

Cluster-based defect detection testing for disk drives

An asynchronous system for testing disk drives includes a test platform that includes a plurality of slots for receiving and for providing communication with drives. The slots are segregated into a plurality of groups configured to satisfy predetermined environmental, communication bandwidth and test schedule requirements of the drives to be loaded therein. An automated loader/unloader is configured to selectively load drives into and out of the platform and to move drives between the plurality of groups. A module controller is assigned to each group of slots, each module controller being coupled to the slots of its assigned group and configured to administer at least one test to drives loaded in its assigned group while insuring that the predetermined environmental, communication bandwidth and test schedule requirements of its assigned group remain satisfied. A test matrix controller controls the loader/unloader to asynchronously move each drive that passes the test(s) administered in one group to a selected empty slot of another group for administration of a next test, to asynchronously move each drive that completes or fails the series of tests out of the platform. The moving steps are carried out without compromising the respective environmental, communication bandwidth and test schedule requirements of the plurality of groups.

Methods and systems for asynchronously testing a plurality of disk drives

An aspect of the invention can be regarded as a method of making disk drives. The method includes providing a frame array. The frame array includes a frame, a plurality of disk drive base portions, and a plurality of tie bars connected between the frame and the disk drive base portions. The method further includes attaching a respective disk drive component to each of the disk drive base portions. The method further includes removing the disk drive base portions from the frame by severing the tie bars.

Method of making disk drives using a frame array with a plurality of disk drive base portions

A method of manufacturing disk drives that are subject to disk pack imbalance includes steps of measuring the disk pack imbalance of each drive and assigning each of the drives to one of a predetermined plurality of categories, depending upon the measured disk pack imbalance. The measured imbalance of the disk drives assigned to fewer than the predetermined plurality of categories may then be reduced. Each category may be associated with one or more customers and the drives assigned to each category may be shipped to the associated customer(s).

Methods for reducing costs and increasing throughput in the manufacture of disk drives by categorizing the disk drives based upon measured disk pack imbalance

A method for reducing written-in runout of a disk drive writes a plurality of servo tracks onto a magnetic-storage portion of a disk that comprises a first radial band proximate the outer circumference of the disk, and a second radial band between the first radial band and the inner circumference of the disk. A first plurality of servo tracks is written to the storage medium in the first radial band at a first servo-writing spin rate. A second plurality of servo tracks is written to the storage medium in the second radial band at a second servo-writing spin rate that is different from the first servo-writing spin rate.

Method for reducing written-in runout during servo track writing of a disk drive

A method and an apparatus for reducing position error signal in a disk drive, which has an actuator and a magnetic medium, write the servo tracks with a servo track writer using a varying increment. The servo tracks are written after the servo track writer incrementally moves the actuator by a non-constant amount. The non-constant incrementing enables a servo track writing operation to write servo tracks that are at least as wide near the outer circumference as they are near the zero skew position or near the inner circumference.

Method for reducing position error signal in a disk drive

A method and an apparatus select the operational spindle rotation rate for a disk drive based on measured performance of the head-disk assembly. The position error values are measured and analyzed to generate a position error metric. Based on the value of the position error metric, an operational spindle rotation rate is selected for use when the head-disk assembly is combined with a controller to produce a disk drive.

Method and apparatus for determining operational spindle rotation rate in a disk drive

A method and an apparatus select the spindle rotation speed for writing servo tracks to a disk based on measured performance of the head-disk assembly. The position error values are measured and analyzed to generate a position error metric. Based on the value of the position error metric, a spindle rotation speed is selected for use when writing servo tracks to a disk.

Method and apparatus for selecting servo track writing speed

A system and method for manufacturing disk drives, the disk drives having reliability attributes and manufacturing attributes, the manufacturing attributes comprising process or component manufacturing attributes is disclosed. The reliability attributes comprise measurements for predicting future reliability of the disk drives at the time of manufacture. The disk drives are prepared with a servo format. Each disk drive is connected to a test apparatus and then tuned to verify that each disk drive performs within expected limits. One or more technical screen tests are performed on all of the disk drives. A first sample set of the disk drives is selected automatically at a defined size using a randomizer. One or more extended tests are executed on the first sample set of disk drives to measure a margin magnitude for one or more of the reliability attributes. The margin magnitude is compared with a reference to detect a significant change. If a significant change in the margin magnitude from the reference is detected, then the defined sample size is adjusted. A second sample set of the disk drives is selected according to the adjusted sample size using the randomizer. The extended tests are then repeated on the second sample set to validate the significant change.

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Laguna Hills, CA, United States of America

Joseph M Viglione