Western Digital (fremont), Inc.

Seagate Technology Incorporated

Jp Morgan Chase Bank

Yong Hu

Eric Thomas Sladek

Hamid Ghazvini

Biao Sun

Ji-Feng Ying

Forhad Hossain

Eric Kenneth Dahlin

Pranesh K Swamy

Shih-Fu Lee

Lanshi Zheng

Elias Ted Johnson, Jr

Eric K Dahlini

A skewed burnishing head arrangement is provided for burnishing the surface of a disc. The skewing of the burnishing head relative to the diameter perpendicular to a sweeping direction provides improved wiping action that catches loose particles and surface contamination, as well as performing aggressive asperity cutting and surface conditioning, while preventing particles from being embedded into a disc surface.

Sweeper burnish head

A slider with an air-bearing surface includes an ID-side leading pad, an OD-side leading pad, an ID-side trailing pad, and an OD-side trailing pad. Each leading and trailing pad includes a respective pocket extending from the respective pad toward the air-bearing surface. The pockets each include a respective step surface surrounded by a trailing-side wall, an ID-side wall, and an OD-side wall. Each step surface has a respective depth, and each pocket is open to a leading side of the pocket. The slider further includes at least one cavity between the leading and trailing pads. The cavity includes a bottom surface of the slider having a cavity depth greater than all of the respective depths of the step surfaces of the pockets.

Slider with an air-bearing surface including four pressure generating pockets for countering disruptive movement

A head has an air bearing surface with left and right leading pressurizing steps. The left and right leading pressurizing steps are each partially surrounded by left and right leading pads, respectively. The left leading pressurizing step includes a left short region that extends for a first distance (measured parallel to the slider longitudinal axis) from the leading face of the slider to the left leading pad. The left leading pressurizing step also includes a left long region that extends for a second distance (measured parallel to the longitudinal axis) from the leading face to the left leading pad. The second distance is at least 25% greater than the first distance. The left short region is disposed closer to the left lateral face than is the left long region. The left long region is disposed closer to the longitudinal axis than is the left short region.

Head with an air bearing surface having left and right leading pressurizing steps, each with short and long regions

A head includes a transducer and a slider having an air bearing surface (ABS) and a trailing face. The slider has an overcoat layer that includes the trailing face and that overcoats the transducer. The ABS includes a trailing pad having a major surface adjacent the transducer, with the major surface lying in a primary plane. The ABS also includes a sub-ambient pressure cavity disposed upstream of the overcoat layer and being recessed from the primary plane by a cavity depth in the range 0.8 to 2 microns. The overcoat layer includes a trailing air flow dam being recessed from the primary plane by a step depth in the range 0.05 to 0.5 microns. The overcoat layer also includes a corner region recessed from the primary plane by at least the cavity depth.

Head with a transducer overcoat having a trailing air flow dam that is shallowly recessed from an air bearing surface

A head has a slider with an air bearing surface having a left trailing air flow dam extending from a trailing pad along a lateral axis, and a right trailing air flow dam extending from the trailing pad along the lateral axis in an opposing direction. A sub-ambient pressure cavity is disposed adjacent to and upstream of at least one of the trailing air flow dams. The trailing pad and the left and right trailing air flow dams together laterally span at least 75% of the width of the slider. Each of the left and right trailing air flow dams is recessed from the primary plane by a step depth in the range 0.05 to 0.5 microns, and the sub-ambient pressure cavity is recessed from the primary plane by a cavity depth in the range 0.8 to 2 microns.

Head with an air bearing surface having a shallow recessed trailing air flow dam

A head for use in an information storage device includes a novel ABS, and a transducer with a heating element. The ABS includes a transducer pad that includes a surface in a first plane. The ABS also includes a pressure-relief trough that is recessed from the first plane by at least 0.1 microns and has an upstream breadth of no more than one fourth of the total length of the slider. The pressure-relief trough is disposed immediately upstream of the transducer pad and continuously spans the total width of the transducer pad. The ABS also includes a flow-diversion dam that has a dam surface that lies in the first plane. The dam surface continuously spans the total width of the transducer pad. The dam surface is disposed immediately upstream of the pressure-relief trough and generally downstream of a sub-ambient pressure cavity.

Head having a transducer heater and an air bearing surface with a flow-diversion dam and pressure-relief trough disposed upstream of the transducer

A head for use in a magnetic hard disk drive or other information storage device includes a novel ABS. The novel ABS includes an inter-cavity dam that is disposed between at least a portion of a cavity and a trailing pad. The inter-cavity dam is spaced longitudinally from the trailing pad by at least one thirtieth of the slider length. The inter-cavity dam includes an OD dam surface and an ID dam surface, with a slider-bisecting longitudinal plane passing between a majority of the OD dam surface and a majority of the ID dam surface. The OD dam surface is recessed from the first plane by an OD dam recession, and the ID dam surface is recessed from the first plane by an ID dam recession that is not equal to the OD dam recession.

Slider with an air bearing surface having a inter-cavity dam with OD and ID dam surfaces of different heights

A hybrid burnishing head for processing of surfaces of hard disk media comprises a solid body including a first major surface and a second, opposed major surface comprising a burnishing surface including first and second surface portions, wherein the first surface portion is configured for providing air bearing stability and flyability of the head over the media surface, the second surface portion is configured for providing burnishing of a media surface, and the first and second surface portions are operatively decoupled for simultaneously providing optimized air bearing stability/flyability and burnishing aggressiveness for a particular application.

Hybrid burnishing head design for improved burnishing of disk media

A system and a method for measuring micro-waviness of a magnetic recording disk using a high-speed glide test are disclosed. The HSG test is a viable production-level test methodology for high performance media that require well-controlled and low micro-waviness.

High speed glide test for screening magnetic disc micro-waviness and a system therefor

The air bearing design consists of four rectangular pads. Each pad features an open rectangular pocket located at the corner of the leading and inner (closer to the disc ID) edges. The pocket opens towards the slider's leading and inner edges. The increase in linear velocity from ID to OD dictates that the slider flies lower at ID than OD. The introduction of the open pocket can effectively offset the difference due to the linear velocity. As we move from ID to OD, the steps that the skewed airflow encounters change from the forward to reverse. Consequently, the lifting force generated by the air compression at the forward steps decrease, while the suction force produced by the air expansion at the reverse step increases, reaching a maximum at OD. Both of them offset the effect of the linear velocity, yielding a constant fly height profile from ID to OD. In addition, the open pockets toward the inner edge generate more air bearing compression for the incoming side flow, improving the ramp-loading dynamic stability under large roll static attitude. The open pocket can be either a step or ramp surface, and the number of pads can be varied. The air bearing design is scalable to achieve different fly heights.

Coil-on-block design with reduced particle accumulation on MO disc drives

A slider which utilizes a set of four pads arranged in a generally rectangular form. The two pads on the leading edge of the slider each include an angled face on their leading edge to facilitate the lift-off of the slider. Behind each leading edge pad is a trailing pad of substantially the same width and separated from the leading pad by a cross-cut channel. The pressure relief provided by the open cross-slot that separates the front and rear pads of each rail of the slider significantly reduces the sensitivity of air bearing pressure to the shape of the disc surface, leading to a very small fly height modulation even when moving over a disc with substantial runout. The rails are separated by a cross-cut. This cross-cut design substantially diminishes the effect of pressure variations which occur owing to the peaks and valleys which exist on discs, especially plastic discs as the slider flies over the surface of the disc.

Air bearing surface design for glide testing of plastic media

The air bearing design consists of four rectangular pads. Each pad features an open rectangular pocket located at the comer of the leading and inner (closer to the disc ID) edges. The pocket opens towards the slider's leading and inner edges. The increase in linear velocity from ID to OD dictates that the slider flies lower at ID than OD. The introduction of the open pocket can effectively offset the difference due to the linear velocity. As we move from ID to OD, the steps that the skewed airflow encounters change from the forward to reverse. Consequently, the lifting force generated by the air compression at the forward steps decrease, while the suction force produced by the air expansion at the reverse step increases, reaching a maximum at OD. Both of them offset the effect of the linear velocity, yielding a constant fly height profile from ID to OD. In addition, the open pockets toward the inner edge generate more air bearing compression for the incoming side flow, improving the ramp-loading dynamic stability under large roll static attitude. The open pocket can be either a step or ramp surface, and the number of pads can be varied. The air bearing design is scalable to achieve different fly heights.

Growing community of inventors

Fremont, CA, United States of America

Yong Hu