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Browse Prior Art Database

Disk With Patterned Overcoat and Flat Magnetic Underlayer

IP.com Disclosure Number: IPCOM000036738D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Cheng, DC: AUTHOR [+5]

Abstract

This article describes a laser-based method to produce texturing on an overcoat for a thin film metal alloy or metal oxide magnetic recording disk, and the process for producing such a disk. The location, shape, and depth of the texturing are highly controlled. No debris is formed, and the magnetic properties of the recording medium are not affected. This method can be easily automated to implement a high throughput manufacturing process.

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This is the abbreviated version, containing approximately 100% of the total text.

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Disk With Patterned Overcoat and Flat Magnetic Underlayer

This article describes a laser-based method to produce texturing on an overcoat for a thin film metal alloy or metal oxide magnetic recording disk, and the process for producing such a disk. The location, shape, and depth of the texturing are highly controlled. No debris is formed, and the magnetic properties of the recording medium are not affected. This method can be easily automated to implement a high throughput manufacturing process.

In this method, a laser with appropriate wavelength is used to ablate the carbon overcoat. The fluence of the laser is kept sufficiently low so that the properties of the underlying magnetic medium are not affected. The overcoat can be removed with a rate of 20 angstroms per pulse at a single pass fluence of about 0.32 J/cm2 with a 308 nm laser. Other wavelengths, such as 248 nm, may also be used for this process.

In the implementation of this general scheme, an optimum pattern mask and a sector mask are combined to form the object mask. The homogenized 248 nm light from an excimer laser is directed onto such an object mask system. Through a lens system,the properly reduced image of the mask system is projected onto the proper sector location of the magnetic disk. After a burst of a couple of pulses, the disk is moved to the next appropriate position and the entire process repeated until the desired area of the disk is completely textured.

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