Western Digital (fremont), Inc.

International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Western Digital Technologies, Inc.

Yu Lo

Shanlin Duan

Hang Fai Ngo

Neil David Knutson

Feng Q Liu

Yunfei Ding

Wentao Yan

David E Fowler

James Hammond Brannon

Bradley Frederick Baumgartner

Norman Chu

Patricia Galindo

Nalin Zhou

Zhigang Bai

Zhanjie Li

Ying Hong

Laurence Lujun Chen

Dehua Han

Timothy A Riener

Yaw-Shing Tang

Wei-Ming Lee

Chengtao R Yu

Connie H Moy

Jorge Daniel Colonia

Karl A Flechsig

Huyen D Do

Yan Liu

The present disclosure generally relates to improved lifetime of a data storage device utilizing an energy assist element. Rather than applying the same current to each energy assist element of a device, each energy assist element has a write current specific to the energy assist element. The unique applied current results in the corresponding energy assist elements having substantially the same temperature during operation. Obtaining substantially the same temperature during operation provides predictable and repeatable device performance and increases the lifetime of the entire data storage device as all energy assist elements should have substantially the same lifetime.

Device lifetime improvement through constant temperature

A method and system test a heat assisted magnetic recording (HAMR) transducer. The HAMR transducer is optically coupled to at least one laser and has an air-bearing surface. The HAMR transducer includes at least one waveguide, at least one near-field transducer (NFT) and a pole. A portion of the NFT(s) resides at the ABS. The laser(s) are optically coupled to the NFT(s). The method and system include energizing the laser(s) at power(s) while the HAMR transducer is not in proximity to a media. The method and system also include measuring an off-disk protrusion of the portion of the NFT(s) at the ABS while the laser(s) are energized and the HAMR transducer is not in proximity to the media.

Method and system for performing off-disk measurements of laser-induced NFT protrusion in a heat assisted magnetic recording transducer

A method fabricates a heat assisted magnetic recording (HAMR) transducer having an air-bearing surface (ABS) and that is optically coupled with a laser. The HAMR transducer includes a write pole, a waveguide, and at least one protective pad. The write pole has a pole tip with an ABS facing surface. The waveguide is located in a down track direction from the pole tip and directs light from the laser toward the ABS. The protective pad(s) are adjacent to the write pole and have front surface(s) at the ABS.

Heat assisted magnetic recording transducer having protective pads

A method and system provide a touchdown sensor for use in disk drive. The touchdown sensor includes a sensor layer including a plurality of magnetic layers interleaved with at least one nonmagnetic layer. The plurality of magnetic layers are magnetically coupled and single domain. Further, the sensor has a temperature coefficient of resistivity (TCR) of at least 0.15%/&#xb0; C.

Laminated touchdown sensor for hard disk drives

A magnetic recording device includes a slider having an air bearing surface (ABS), a leading side, and a trailing side and a head residing on the slider. The head has a first magnetic transducer and a first heater for heating an area proximal to the first magnetic transducer. A first shield (S1) comprising a first material is on the leading side of the first magnetic transducer and a second shield (S2) comprising the first material is on the trailing side of the first magnetic transducer. A first pole (P1) comprising the first material is on the trailing side of the second shield (S2), and the first pole (P1) is between 0.6 micron and 2.0 micron thick; and the second shield (S2) is less than 0.6 micron thick. A hard disk drive includes the magnetic recording device.

Magnetic recording head with dynamic fly height heating and having thermally controlled pole tip protrusion to control and protect reader element

A method and system provide a magnetic read and/or write transducer for use in disk drive. A read transducer has an air-bearing surface (ABS) and includes a read sensor, a nonmagnetic gap, a heater, and an expander. The nonmagnetic gap is adjacent to a portion of the read sensor and has a first coefficient of thermal expansion (CTE). The heater heats a portion of the magnetic read transducer. The expander is adjacent to a portion of the nonmagnetic gap and has a second CTE greater than the first CTE. The write transducer includes a pole, a coil, an insulator adjacent to and for insulating the coil, a heater and an expander. The expander has a CTE greater than the insulator's CTE.

Method and system for providing enhanced thermal expansion for hard disk drives

A glide head calibration technique uses two fly height calibrations on a disk media certifier. The first calibration point uses a spin down on bump technique at a first height, and the second calibration point uses a spin down on disk media roughness at a second lower height. With two height data points, a fly height curve of each glide head is approximated very accurately. Once the fly height curve is derived for each head, any fly height can be dialed-in by the disk media certifier for glide testing. This technique achieves glide fly heights between about 4 nm and 8 nm and does so with improved tolerances.

System, method, and apparatus for glide head calibration with enhanced PZT channel for very low qualification glide heights

A method is presented for glide testing a disk which tests the glide head fly-height by inducing a collision between the glide head and a disk under test. The glide test system is initially calibrated using calibration disks. The method of the invention periodically tests the calibration without interrupting the production testing by lowering the rotation rate until the glide head collides with the rotating disk surface. The rotation rate at which the collision occurs is then compared with the value expected based on knowledge of disk samples and the initial calibration. Parameters for acceptable high and low values are established to detect changes in the glide test system performance to trigger automatic or manual recalibration.

Glide testing of disks with calibration confirmation testing by inducing collision of the slider with production disk surface

A disk for calibrating glide heads utilizes a dual-zone configuration of multiple laser melt bumps having selected heights. Averaging the PZT response over many bumps significantly narrows the response distribution, resulting in greater certainty and correlation of the PZT amplitude to bump height. The multiple calibration bumps are circumferentially arranged on a disk surface at a selected radius in a ring-like manner. A second head cleaning zone is provided near the inner diameter of the disk to provide for increased reproducibility of the PZT calibration response. The second zone is densely textured and serves to clean the glide head prior to its use in the calibration zone.

Apparatus and method for glide height calibration of disk surfaces by use of dual-zone laser texture

A bump disk for accurate glide calibration has a new type of glass laser melt bumps that give the same signal amplitudes as conventional AlMg laser melt bumps for the same bump height. The present invention provides a solution to switch the calibration bumps from AlMg to glass, and can be used in disk manufacturing lines to save 30% on the cost of hard disks from inaccurate glide certification processes. The solution is to trim or burnish away loose and/or high particles on production disks before the glide tests. This additional processing step causes the responses from the glass bumps to become very similar to those of the AlMg bumps, thereby enabling glass and AlMg disks to become materially compatible.

Disk drive laser melt bump disk for accurate glide calibration and certification processing

Method for burnishing hard disks

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Foster City, CA, United States of America

Yu Lo