Apparatus and method for reducing disc surface asperities to sub-microinch height

Abstract

A honing head for microburnishing surface of a recording/reproducing disc to a smoothness at which asperities are limited to submicron heights including a hardened contact bearing surface having an array of depressions with abrupt trailing edges interconnected by recessed channels leading outwardly from the honing head. The array of channels span a band in which an asperity may be present, and the sharp edges shear off the asperities within the band which extend above the chosen submicroinch height, with the separated particulates being passed through the recesses and channel system to the outer edge of the honing head. The trailing edges act to shear off the unwanted heights of the asperities, while the recesses enable pressure differentials and air flows to direct the separated particulates outwardly relative to the disc, centripetal forces of rotation bearing the particulates from the disc. A diamond-like coating on the entire contact bearing surface and the recesses aids in reducing wear and the stiction of the smooth surfaces to the disc that is being burnished. This arrangement has the further advantage that the honing head may be prepared by photomicrolithographic techniques to generate the array of recesses on a production basis, with the recesses having precisely determined depths and perpendicular trailing edge walls. Ion milling and other known techniques can be used to remove the materials in the chose patterns quickly and efficiently.