# US 5,345,353 A · Step projection air bearing slider with improved stiction performance and wear resistance

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- Number: US 5,345,353 A
- Document ID: US5345353A
- Status: Granted
- Kind: A
- Application number: 07/948,182
- Filed: 1992-09-21
- Granted: 1994-09-06
- Earliest claimed: 1992-09-21
- Assignees: International Business Machines Corporation
- Inventors: Matthias C. Krantz; Vlad J. Novotny; Timothy C. O'Sullivan; Andrew C. Tam
- Web page: https://patentgrep.com/patent/US5345353A

## CPC

- G11B 5/6005: {Specially adapted for spacing from a rotating disc using a fluid cushion}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

Slider disk stiction is reduced in a disk-based storage device by providing one or more step projections on the air bearing surface of a slider. The rear part of the step projections which rest on the disk surface projections are forward of the slider pivot point. When the slider rests on a disk surface, the step projections elevate the leading edge of the slider, which imposes a static pitch angle on the slider, reducing the slider/disk contact area. Provision is also made for contouring the slider air bearing surface adjacent to the slider leading edge, using a taper or the step projection leading face, to compress the airflow and provide a stable slider air bearing during disk file operation.

## Claims

### Claim 1

A reduced-stiction slider assembly, comprising:
a slider body with a slider leading edge and a slider trailing edge;
a pivot pint on the slider boy;
a plurality of air bearing surfaces on the slider body, which extend between the slider leading edge and the slider trailing edge; and,
a projection on at least one of the air bearing surfaces, the projection extending outwardly from the at least one air bearing surface, the projection having a height h with respect to the at least one air bearing surface and being located on the at least one air bearing surface between the slider leading edge and the pivot point;
the projection including:
a front edge facing toward the slider leading edge and
a rear edge facing toward the slider trailing edge;
a step transition from the rear edge to the at least one
air bearing surface; and
a tapered transition tapering in height from the front edge to the slider leading edge.

### Claim 2

A reduced-stiction slider assembly, comprising:
a slider body with at slider leading edge and a slider trailing edge;
a pivot point on the slider body;
a plurality of air bearing surfaces on the slider body, which extend between the slider leading edge and the slider trailing edge;
a tapered transition tapering in height from at least one of the air bearing surfaces to the leading edge of the slider; and
a projection extending outwardly from the at least one air bearing surface, the projection have a height h with respect to the air bearing surface and being located on the air bearing surface between the slider leading edge and the pivot point;
the projection including:
a front tapered transition portion overlaid on the tapered transition and extending to the slider leading edge;
a rear edge facing toward the slider trailing edge; and
a step transition from the rear edge to the at least one air bearing surface.

### Claim 3

A reduced-stiction slider assembly, comprising:
a slider body with a slider leading edge and slider trailing edge;
a pivot point on the slider body;
a plurality of air bearing surfaces on the slider body, which extend between the slider leading edge and the slider trailing edge; and
a projection extending outwardly from at least one air bearing surface, the projection having a height h with respect to the at least one air bearing surface and being located on the at least one air bearing surface between the slider leading edge and the pivot point;
the projection including a front edge facing toward the slider leading edge and a rear edge facing toward the slider trailing edge;
a plurality of step transitions in the front edge; and
a step transition from the rear edge to the at least one air bearing surface.

### Claim 4

A magnetic recording system, comprising:
a magnetic recording medium having a recording surface;
means for moving the magnetic recording medium;
a magnetic transducer and a slider supporting the transducer;
a pivot point on the slider;
means connected to the slider for supporting the slider adjacent to the recording surface in response to movement of the magnetic recording medium and for supporting the slider against the recording surface when the magnetic recording medium is at rest;
the slider including a slider leading edge and slider trailing edge;
at least one air bearing surface on the slider extending in a longitudinal direction between the slider trailing edge and the slider leading edge, the air bearing surface facing the recording surface; and
a projection means on the air bearing surface between the slider leading edge and a locus through the pivot point, the projection means for contacting the recording surface to maintain a static pitch angle between the air bearing surface and the recording surface when the magnetic recording medium is at rest;
the projection means including:
a front edge facing toward the slider leading edge and
a rear edge facing toward the slider trailing edge;
a tapered transition tapering in height from the front edge to the slider leading edge; and
a step transition from the rear edge to the at least one air bearing surface.

### Claim 5

A magnetic recording system, comprising:
a magnetic recording medium having a recording surface;
means for moving the magnetic recording medium;
a magnetic transducer and a slider supporting the transducer;
a pivot point on the slider;
means connected to the slider for supporting the slider adjacent to the recording surface in response to the movement of the magnetic recording medium and for supporting the slider against the recording surface when the magnetic recording medium is at rest;
the slider including a slider leading edge and a slider trailing edge;
at least one bearing surface on the slider extending in a longitudinal direction between the slider leading edge and the trailing edge, the bearing surface facing the recording surface;
a tapered transition tapering in height from the bearing surface to the slider leading edge; and
projection means on the bearing surface between the slider leading edge and a locus through the pivot point for contacting the recording surface to maintain a static pitch angle between the bearing surface and the recording surface when the magnetic recording medium is at rest; the projection means including:
a front tapered transition portion overlaid on the tapered transition and extending to the slider leading edge; and
a rear edge and a step transition from the rear edge to the bearing surface.

### Claim 6

A magnetic recording system, comprising:
a magnetic recording medium having a recording surface;
means for moving the magnetic recording medium;
a magnetic transducer and a slider supporting the transducer;
a pivot point on the slider;
means connected to the slider for supporting the slider adjacent to the recording surface in response to movement of the magnetic recording medium and for supporting the slider against the recording surface when the magnetic recording is at rest;
the slider including a slider leading edge and slider trailing edge;
at least one bearing surface on the slider extending in a longitudinal direction between the slider leading edge and the slider trailing edge, the bearing surface facing the recording surface; and
projection means on the bearing surface between the slider leading edge and a locus through the pivot point for contacting the recording surface to maintain a static pitch angle between the bearing surface and the recording surface when the magnetic recording medium is at rest;
the projection means including:
a front edge facing the slider leading edge and including a plurality of step transitions; and
a rear edge with a step transition to the bearing surface.