Western Digital Technologies, Inc.

Western Digital (fremont), Inc.

Kathy X Tang

Jai N Subrahmanyam

Jerry G Le

Jack M Chue

Loi Dac Pham

Gopalakrishna Kote

Xiao Z Wu

Donald Joseph Brunnett

Hong Pan

Qingzhi Peng

Rahmat Karimi

A data storage device is disclosed wherein when a first head is over a top disk surface, a first undershoot of a first cross-track profile is closer to an inner diameter of a disk and a second undershoot of the first cross-track profile is closer to an outer diameter of the disk. When a second head is over a bottom disk surface, a second undershoot of a second cross-track profile is closer to the inner diameter of the disk and a first undershoot of the second cross-track profile is closer to the outer diameter of the disk.

Data storage device employing mirrored cross-track profiles for top and bottom disk surfaces

A data storage device is disclosed comprising a disk comprising a plurality of data tracks, and a head actuated over the disk. A retry operation for a target data track is performed by positioning the head at a first radial location and first erasing at least part of a first data track adjacent the target data track. After the first erasing, the target data track is first read to first recover target data recorded in the target data track. When the first recovery fails, the head is positioned at a second radial location and more of the first data track is second erased. After the second erasing, the target data track is second read to second recover the target data recorded in the target data track.

Data storage device erasing multiple adjacent data tracks to recover from inter-track interference

An apparatus includes: a media; a head over the media; and control circuitry configured to cause the head to: write a first precondition track with a preconditioning pattern on the media, and write a data track on the media at a first inter-track spacing with the head positioned in a first direction from the first precondition track.

Electronic system with media preparation mechanism and method of operation thereof

A data storage device is disclosed comprising a plurality of disk surfaces, and a head actuated over each disk surface. For each disk surface, a quality metric is measured at a plurality of discrete areal densities including a first areal density comprising a first radial density and a first linear density, and a second areal density comprising a second radial density different from the first radial density and a second linear density different from the first linear density. Based on a target capacity, an areal density is selected for each disk surface such that the combined areal densities satisfies the target capacity and such that the quality metrics across the disk surfaces are substantially equal and substantially maximized.

Data storage device balancing and maximizing quality metric when configuring arial density of each disk surface

A data storage device is disclosed comprising a head actuated over a disk. A first spacing pattern is written to the disk and a second spacing pattern is written to the disk different from the first spacing pattern. A first fly height measurement (FHM1_1) is generated by reading the first spacing pattern and a first fly height measurement (FHM2_1) is generated by reading the second spacing pattern. After an interval, a second fly height measurement (FHM1_2) is generated by reading the first spacing pattern and a second fly height measurement (FHM2_2) is generated by reading the second spacing pattern. A change in the fly height of the head is estimated based on:(&#x394;2&#x2212;1)/()where &#x394;FHM1 represents a difference between FHM1_1 and FHM1_2, &#x394;FHM2 represents a difference between FHM2_1 and FHM2_2, and A and B are constants.

Data storage device attenuating thermal decay effect on fly height measurement

A method of detecting skip track erasure for a head and disk of a disk drive is disclosed. N tracks are DC erased, and a periodic pattern is written to the disk at a target track within the DC erased tracks. The periodic pattern is substantially comprised of a high frequency component greater than 450 MHz. After writing the periodic pattern to the target track at least twice, at least two of the DC erased tracks other than the target track are read to generate respective read signals. The read signals are processed to detect a skip track erasure event.

Writing high frequency pattern over a DC background to detect skip track erasure for a disk drive

A head stack assembly includes a flex cable assembly. The head stack assembly further includes an actuator arm and a load beam coupled to the actuator arm. The head stack assembly further includes a trace suspension assembly backing layer coupled to the load beam and including a gimbal. The head stack assembly further includes a dielectric layer disposed upon the trace suspension assembly backing layer. The head stack assembly further includes a slider supported by the gimbal. The head stack assembly further includes a ground trace disposed upon the dielectric layer with the dielectric layer between the ground trace and the trace suspension assembly backing layer. The ground trace extends along the actuator arm and is electrically connected to the slider and the flex cable assembly for grounding the slider to the flex cable assembly.

Head stack assembly including a trace suspension assembly backing layer and a ground trace for grounding a slider

According to an aspect of the present invention, there is provided a slider for a disk drive. The slider includes a slider body including a slider body outer surface. The slider further includes an inductive write head including main and return poles. The slider further includes a slider ground pad disposed at the slider body outer surface. The slider ground pad is disposed in electrical communication with the main and return poles for electrically grounding the main and return poles.

Slider with a slider ground pad electrically connected to write head poles and read head shields

A Head Gimbal Assembly (HGA) for use in a disk drive and comprising an ESD-protected slider comprising a head formed on a slider substrate. The slider may comprise an electrical-isolation circuit; an electrically-resistive path between head input connections and the slider; or both isolation circuits and resistive paths for reducing electrostatic charge on the slider while remaining connected during disk drive operations.

ESD-protected slider and head gimbal assembly

A disk drive includes a disk having a recording surface, a head stack assembly that includes a body portion, an actuator arm cantilevered from the body portion and a head gimbal assembly supported at the actuator arm. The head gimbal assembly includes a suspension having a first end and a second end, the first end being attached to the actuator arm, a slider coupled to the second end of the suspension, the slider comprising a transducer for reading from and writing to the recording surface. A gimbal is coupled to the second end of the suspension and to the slider. An array of diodes is attached to the suspension to protect the transducer from electrostatic discharge or electrical overstress events.

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San Jose, CA, United States of America

Kathy X Tang