US 7,070,703 B2Granted

Process for producing glass disk substrates for magnetically recordable data storage disks

AssigneeHitachi Global Storage Technologies Netherlands B.V.

InventorsFrederick P. Benning, Steven L. Maynard, David C. Paurus, Jon Edward Podolske

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Abstract

A polished glass disk is prepared for a magnetically recordable coating by texturing the surfaces with a highly abrasive material being abrasively engaged with the surfaces as the disk is rotated, thereby creating a relatively coarse texture with the abrasions concentric with the axis of rotation of the disk. Thereafter, the roughness of the texturing is reduced by abrading the surface of the disk with a polishing pad and an etchant slurry of colloidal silica. The etchant component has the property of attacking or softening the glass disk during the fine polishing with the colloidal silica slurry. As both the texturing step and the fine polishing step deposit a plurality of concentric abrasions on a glass disk, these abrasions aid in retaining the magnetically recordable coating deposited thereon to complete a magnetically recordable disk for use as a data storage member.

Claims7

Dependent claims

A process of manufacture for producing glass disk substrates for magnetically recordable data storage disks comprising the steps of:

providing a circular flat disk of glass with a hole centered therein;
performing a first polishing process on the glass disk, the first polishing process being a rough isotropic polishing process for forming scratches on the disk, wherein the scratches are not concentric;
after performing the first polishing process, performing a second polishing process on the glass disk, the second polishing process being a fine isotropic polishing process;
chemically strengthening the disk;
after chemically strengthening the disk, texturing the disk to form a plurality of scratches formed as discontinuous, concentric arcs of random length and depth, wherein the texturing of the disk comprises:
engaging a cylindrical polishing pad with a surface of the disk, the polishing pad having an axis oriented parallel with a radius of the disk;
rotating the disk;
rotating the cylindrical polishing pad about its axis, counter to the direction of travel of the disk;
and
applying a diamond slurry;
and
after texturing the disk, performing a third polishing process, the third polishing process being a fine polishing processes performed by engaging a cylindrical polishing pad with a surface of the disk, the cylindrical polishing pad having an axis oriented parallel with a radial axis of the disk, rotating the polishing pad about its axis, and applying an etching solution.

9 more elements

Dependencies are inferred from the claim text.