International Business Machines Corporation

Seagate Technology Incorporated

Luis P Franco

Moris Musa Dovek

Ellis T Cha

Andrew M Homola

John S Foster

Jia-Kuen Jerry Lee

Michael Lee Workman

George L Best

Ian L Sanders

Randall T Kerth

Erich Sawatzky

Herman E Bleich

Roland Eugene Imboden

Leela Viswanathan

An improved media defect glide test head assembly which incorporates a wide thermo-resistive (TR) element suitable for detection of thermal asperities on the surfaces of magnetic recording discs. The TR element of the inventive glide test head assembly is very wide when compared to magneto-resistive (MR) elements in normal MR read/write heads. In the currently preferred embodiment, the TR element is envisioned to be as wide as is possible to fabricate on the trailing edge of an air bearing element of the glide test head assembly, to enable detection of thermal asperities across a relatively wide band of disc surface during each disc rotation, thus enabling rapid testing of the media surface. In a second aspect of the invention, the wide TR element is envisioned to be formed of nickel or other material having a large thermal resistance coefficient. In a third aspect of the invention, the wide TR element is envisioned to include intermediary taps which permit more precise mapping of the location of thermal asperities. Control logic for implementing mapping of TR-detected disc defects is also disclosed.

Thermo-resistive glide test head for disc drive recording media

For use in a disk drive, a head comprising a slider having a bottom air bearing surface, a leading edge and a trailing edge; a magnetic transducer mounted by the slider at the trailing edge of the slider; and a protective overcoat adhered to the air bearing surface of the slider and having a leading edge and a trailing edge. The trailing edge of the protective overcoat being spaced from the trailing edge of the slider such that the minimum distance from the slider to the surface of a disk in the disk drive is between the magnetic transducer and the disk surface.

Partially etched protective overcoat for a disk drive slider

For use in a disk drive, a head comprising a slider having a bottom air bearing surface, a leading edge and a trailing edge; a magnetic transducer mounted by the slider at the trailing edge of the slider; and a protective overcoat adhered to the air bearing surface of the slider and having a leading edge and a trailing edge. The trailing edge of the protective overcoat being spaced from the trailing edge of the slider such that the minimum distance from the slider to the surface of a disk in the disk drive is between the magnetic transducer and the disk surface. A method for manufacturing a slider with an overcoat spaced from the trailing edge of the slider includes applying a carbon overcoat to the entire bottom air bearing surface, masking, and oxygen plasma etching exposed portions of the overcoated.

A data recording disk drive has an improved head-disk interface provided by a transducer carrier which is essentially a low-flying air-bearing slider that is also able to be in contact and near contact with the lubricant film on the disk. The slider has a front air-bearing surface in the form of a pair of equally-spaced air-bearing pads, a rear air-bearing pad, and a central nonair-bearing recessed surface which separates the front and rear air-bearing pads. The two front pads have a surface area greater than that of the rear pad and thus provide a positive pitch up of the slider. This causes the rear pad to also be pitched up so that air can flow beneath the rear pad to generate an air bearing in the rear portion of the slider. The presence of the central nonair-bearing region eliminates any lift in the central part of the slider, which allows for the low-flying height. The flying height of the rear pad of the slider above the disk is controlled by the width of the rear air-bearing pad. The rear pad has its leading edge wider than its trailing edge so that it is able to withstand contact with the lubricant film on the disk, typically at the lower disk velocities near the disk inside diameter, without generating unacceptable drag forces or depleting the lubricant from the disk. The rear pad also has a skewed leading edge which compensates for skew of the slider to minimize the flying height variation from the disk inside diameter to outside diameter.

Slider with transverse ridge sections supporting air-bearing pads and

A contact start/stop (CSS) disk file has an improved head-disk interface which has significantly reduced static friction between the head-supporting slider and the disk. The slider has a plurality of narrow skids which project from the air-bearing surface of the slider and support the air-bearing surface off the disk when the disk file is not operating. The skids are designed to not affect the flyability of the slider and contain a protective overcoat to minimize wear at the head-disk interface.

Disk file with air-bearing slider having skids

A data recording disk file of the liquid-bearing type has an improved head-disk interface provided by a transducer carrier with new properties. The carrier supports a conventional head for reading and writing data to the disk. The carrier has an air-bearing surface near its front end, a ski pad near its rear end, and a plurality of ski feet or struts which support the air-bearing surface off the liquid film of the disk when the disk file is not operating. The air-bearing surface is in the form of a pair of air-bearing rails located forward and outboard of the rear ski pad so that no air-bearing effect occurs in the rearward region of the carrier to assure the skiing action of the rear ski pad. The struts are separated from the air-bearing rails to not interfere with their air-bearing performance and support the rails away from the liquid film on the disk. In one embodiment there are at least three struts arranged on the carrier so that both the air-bearing rails and the ski pad are supported off the liquid film when the disk file is not operating. As operational speed is approached the air-bearing effect causes the front end of the carrier to rotate about the two rear struts, thus raising the forward strut(s) and the air-bearing rails off the disk and lowering the rear ski pad into contact with the liquid film.

Liquid-bearing data recording disk file with transducer carrier having

A method is described for depositing a thin protective carbon film on the air bearing surface of a slider in a magnetic recording disk file. A disk file with a conventional slider and a disk with an essentially carbon protective overcoat is cycled on and off at a frequency such that the slider is maintained in contact with the disk. Alternatively, the disk is rotated at a low constant speed so that the slider is maintained in contact with the disk. In both cases, carbon is transferred from the carbon overcoated disk to the air bearing surface of the slider such that during subsequent operation of the disk file, the disk file has excellent durability, especially when operated at relatively low humidity, as is required in those disk files which use a magnetoresistive sensor on the slider.

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Gilroy, CA, United States of America

Luis P Franco