International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

David C Paurus

James Aloysius Hagan

Frederick Paul Benning

Steven L Maynard

Jon Edward Podolske

Douglas Howard Piltingsrud

Bruce Peter Kruger

Thomas E Priebe

A self-cleaning colloidal slurry and process for finishing a surface of a glass, ceramic, glass-ceramic, metal or alloy substrate for use in a data storage device, for example. The slurry comprises a carrying fluid, colloidal particles, etchant, and a surfactant adsorbed and/or precipitated onto a surface of the colloidal particles and/or substrate. The surfactant has a hydrophobic section that forms a steric hindrance barrier and substantially prevents contaminates, including colloidal particles, from bonding to the substrate surface. The slurry is applied to the surface of the substrate while a pad mechanically rubs the surface. Subsequent cleaning with standard soap solutions removes substantially all remaining contamination from the substrate surface. In an exemplary embodiment, the slurry is used to superfinish a glass disk substrate to a surface roughness of less than 2 &#x212b;, with substantially no surface contamination as seen by atomic force microscopy (AFM) after standard soap cleaning steps.

Self-cleaning colloidal slurry composition and process for finishing a surface of a substrate

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.

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

The circumferential edges of glass or ceramic disks used in disk drive data storage devices are preferably finished by ductile grinding to produce an essentially fracture-free surface, which is not chemically strengthened. Preferably, the material is glass, and both the inner and outer edges of the disk are finished. Edge finishing is preferably achieved in a two-stage process, involving a coarse grind and a ductile grind, using air bearing spindles rotated at high speed for grinding wheels and workpiece. Preferably, the grinding wheels are shaped to provide a radius at the juncture of the circumferential edges and flat disk surfaces.

Edge finishing process for glass or ceramic disks used in disk drive data storage devices

A method of preparing for a disk polishing operation includes providing a polishing machine having a first and a second superposed platen. A first polishing pad is on the first platen and a second polishing pad is on the second platen. A plurality of carriers are disposed between the first and second polishing pads. Each carrier is adapted to rotate relative to the polishing pads and is adapted to carry at least one glass disk. A pressure, temperature and rotational speed of the polishing machine used during a disk polishing operation are determined. A number of diamond disks are provided. A diamond disk is placed in respective ones of the carriers. The polishing machine is operated at or near the determined pressure, temperature and rotational speed while simultaneously dressing the respective surfaces of the polishing pads using the diamond disks.

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Byron, MN, United States of America

David C Paurus