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Laser Texture Bump Design

IP.com Disclosure Number: IPCOM000015018D
Original Publication Date: 2002-Jun-03
Included in the Prior Art Database: 2003-Jun-20
Document File: 2 page(s) / 150K

Publishing Venue

IBM

Abstract

Laser texturing technology has been extensively used in the disk drive industry for the last few years. The main application of the laser-produced bumps, in altering disk surface topography, is zone texturing to provide a landing and take-off area for the slider head to improve contact start/stop, CSS, operation. To optimize drive performance in CSS operation, it is common to maintain the bump height and bump diameter in a range that reduces stiction without compromising durability.

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Laser Texture Bump Design

Laser texturing technology has been extensively used in the disk drive industry for the last few years. The main application of the laser-produced bumps, in altering disk surface topography, is zone texturing to provide a landing and take-off area for the slider head to improve contact start/stop, CSS, operation. To optimize drive performance in CSS operation, it is common to maintain the bump height and bump diameter in a range that reduces stiction without compromising durability.

Laser-generated bumps also find their application in the disk glide height qualification process. A glide-testing piezo-head, PZT-head (with a piezo-crystal mounted on the back of the slider), generates electrical signal when it contacts a mechanical defect on a disk. Laser-produced bumps are used to simulate mechanical defects of known height for calibration of glide piezo-heads used in the glide height qualification test. In the calibration process of glide heads, it is of interest to optimize the electrical signal generated when contact between the glide head and a laser bump occurs.

As a means of optimizing laser bump performance in these applications, besides maintaining the bump height, diameter, and spacing, it is also desired to have the capability of controlling the bumps geometrical shape. This publication briefly describes an optical technique / process that produces elliptical bumps on finished glass magnetic disk utilizing the existing Vanadate-laser-based texturing tools.

This technique employs an assembly of two cylindrical lenses to make a "cylindrical telescope" that:

Converts a circular-shape laser beam into an elliptical-shape beam.

Allows adjusting the aspect ratio of the elliptical beam, e.g., by adjusting the distance between the two cylindrical

lenses. Allows rotation of the axes of the elliptical beam in space by rotating the telescope about the beam axes ( e.g., by

installing the telescope...