International Business Machines Corporation

Komag Corporation

Wd Media, LLC

Asahi Glass Company, Limited

Other

Christopher H Bajorek

Andrew M Homola

David A Thompson

Gerardo Bertero

David Treves

David E Wachenschwanz

Thomas W Glaser

James L Chao

Gordon James Smith

Klaas Berend Klaassen

Bruce M Harper

Charles R Nielsen

George R Santana

Kie Y Ahn

Dudley A Chance

Michael L Workman

Chung W Ho

Cheng Tzong Horng

Robert Fontana

Neil Leslie Robertson

Albert John Wallash

A David Erpelding

Surya Narayan Pattanaik

Glen A Garfunkel

Robert Rosenberg

Robert J Miller

Thomas Anthony O'Dell

Richard Greenberg

King-Ning Tu

John R Reidenbach

Paul S Ho

Celia E Yeack-Scranton

Sol Krongelb

Mason L Williams, Iii

David Vigdor Salamon

John V Powers

Robert D Hempstead

Edward T Yen

Clint D Snyder

John Hsieh

Toshiyuki Max Saito

Holland Hodges

Ashok Frank Mayadas

Jerr L Neubauer

A storage device and method use a head that is fabricated using photolithography, and the head is purposely powered up during a material removal process, such as lapping, so that the head's expansion (that would be formed on being powered up during normal usage in a drive) is planarized. On being cooled to room temperature, the head has a concave shape in a pole tip region, the concavity indicative of a volume occupied by material that formed the head expansion, and that has been removed by planarization. Thereafter, the head is powered up in a storage device and method, so that the head has a surface other than flat but within a predetermined range, and the head supplies a signal through the surface to a recording medium.

Storage device and method of using a head that has a concave surface when powered down

A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.

Perpendicular magnetic recording disk with a soft magnetic layer having a discrete track recording pattern

Perpendicular magnetic discrete track recording disk

A method of forming a discrete track recording pattern in a magnetic recording disk. In one embodiment, the discrete track recording pattern may be formed in a NiP layer continuous throughout the discrete track recording pattern. Alternatively, the discrete track recording pattern may be formed in a substrate.

Method of fabricating a magnetic discrete track recording disk

Isothermal imprint embossing system. In one embodiment, the system includes a heater to pre-heat a disk substrate to an embossing temperature, a die assembly with an embossing foil to imprint the embossable film disposed on the disk substrate, and a heat tunnel disposed between the heater and the die assembly to maintain the embossing temperature.

Isothermal imprint embossing system

A press system that reduces contamination of workpieces and/or compliant members used in die assemblies of the press from the pressing process. The die assemblies may utilize annular or hole-less stampers in which the compliant member is sealed in the die assembly. The compliant member may have be annular having a cavity at approximately its center. A gap may be generated at the cavity of the compliant member between a constraint member and the stamper. The gap, for example, may be filled with a plug to prevent significant distortion of the stamper over a hole of a disk shaped workpiece due to the pressure induced force generated by the press system. An outer diameter ring surrounding a workpiece may be used to prevent collapse of the stampers outside the diameter of the workpiece to insure uniform pressing out to the outer diameter of the workpiece.

Die set having sealed compliant member

A die for a press system. The die may include a stamper and a housing, having a cavity disposed therein, coupled to the stamper. The die may also include a gasket disposed within the cavity. The gasket may be coupled to the stamper at a position above a workpiece to be imprinted by the stamper.

Die set utilizing compliant gasket

A head for use in a drive includes a heating element capable of generating heat sufficient to cause the head to have a shape that is similar or identical to the shape that the head has when performing an operation (e.g. writing) on a recording medium in the drive. The heating element is activated when the operation is not being performed. Hence, a head generates the same amount (or similar amount) of heat and is therefore at the same temperature (also called 'operating temperature'), regardless of whether or not an operation (such as writing) is being performed. Therefore, the head maintains a fixed shape or has a shape that varies minimally, within a predetermined range around the fixed shape, that in turn results in maintaining fly height (distance between the head and the recording medium). The heating element may be implemented to use loss mechanisms inherent in a write transducer, e.g. by providing a center tap to the write transducer. When using a center tapped write transducer, currents in phase with one another are provided to perform a write operation. When not performing the write operation, the same currents are provided, but out of phase.

Storage device including a center tapped write transducer

A head is fabricated using photolithography, and the head is purposely powered up during a material removal process, such as lapping, so that the head's expansion (that would be formed on being powered up during normal usage in a drive) is planarized. Specifically, the head is energized in a manner identical (or similar) to energization of circuitry in the head during normal operation in a drive, even though fabrication of the head has not yet been completed. When energized, a shape that the head would have during normal operation is replicated (or approximated). Therefore, the head's shape includes a expansion of the pole tip region, although the head is only partially fabricated. Thereafter, a portion of the head in the expansion is partially or completely removed, by lapping while energized. The depth of material removal from the head is monitored e.g. by a controller sensitive to a change in electrical characteristic of a device (such as a resistor) that is normally fabricated during photolithography of the head.

Lapping a head while powered up to eliminate expansion of the head due to heating

A method for manufacturing a glass substrate for use in magnetic disk manufacturing comprises the steps of a) forming a glass sheet; b) forming a protective sheet over one or both sides of the glass sheet; c) cutting the glass sheet into workpieces; d) cutting the workpieces into disk-shaped substrates; e) subjecting the edges of the substrates to an edge polishing process; and f) removing the protective layer. Of importance, by leaving the protective layer over the substrate, the substrate surface is protected from damage.

Method for manufacturing a magnetic disk comprising a glass substrate using a protective layer over a glass workpiece

A method for manufacturing a magnetic disk comprises the step of applying a continuous laser beam to both sides of a glass workpiece and etching both sides of the workpiece with an aqueous acidic fluoride-containing etching solution. The portion of the workpiece receiving the laser beam etches at a much faster rate than the portions of the workpiece that were not exposed to the laser beam. The workpiece is then broken along a line or curve formed by the above-mentioned steps. The resulting structure is a substrate used to form a magnetic disk. The disk is completed by depositing an underlayer, a magnetic layer and a protective overcoat on the substrate.

Method for manufacturing a magnetic disk

A method for making a credit card (or other type of data storing card) comprising a magnetic strip includes the step of depositing a magnetic recording layer on a substrate, cutting the substrate into strips, and mounting the strips onto the credit card. In one embodiment, the strips comprise glass that is sufficiently thin to be bendable. The magnetic recording layer is sputtered onto the glass using a high temperature sputtering apparatus. In another embodiment, the substrate is a metal foil. The data recording capacity of the magnetic strip is greater than that which can be achieved by using particulate media.

Method for manufacturing a data storage card

A method for making magnetic disks comprises the steps of: applying a protective layer of material on a sheet of glass; b) cutting the sheet of glass into glass squares; c) stacking the glass squares; d) removing a circular core from the stack of glass squares, thereby defining the inner diameter of the glass substrates being formed; e) using a cutting annulus to cut through the stack of glass squares, thereby forming a stack of glass disks; f) subjecting the stack of glass disks to an edge polishing process to round the corners of the glass disks both at the inner and outer diameters; h) unstacking the glass disks; i) removing the protective layers from the glass disks; j) subjecting the glass disks to a chemical strengthening step; and k) sputtering an underlayer, magnetic layer and protective overcoat onto the glass substrate to thereby form a magnetic disk.

Method for manufacturing a magnetic disk including a glass substrate

A disk drive power manager that compares energy usage with a predetermined profile to select one of several reduced-power operating modes. An energy usage register is updated at regular intervals according to the energy used during each time interval. An attenuated average energy usage value is obtained by attenuating the energy usage measures over time and integrating the results. The average energy level is compared with several predetermined energy threshold profiles to select a full- or reduced-power operating mode. Operating mode selection automatically adapts to the usage pattern to optimally balance power consumption with operational accessibility.

Adaptive system for optimizing disk drive power consumption

Growing community of inventors

Los Gatos, CA, United States of America

Christopher H Bajorek