Ground disk substrate especially of glass or glass-ceramic for computer hard disk manufacture

摘要

A disk substrate, with good flatness has ground surfaces with a specified height of irregularities produced by grinding. A disk substrate, in which both surfaces have been ground by a grinding stone, has <= 10 mu flatness and 0.05-1.0 mu height difference of irregularities produced by grinding. An Independent claim is also included for a disk substrate production process comprising successively grinding both faces of a disk substrate material such that the same amount of residual deformation is applied to each surface so that a flatness of <= 10 mu is maintained. Preferred Features: The substrate consists of an inorganic material, especially glass or glass-ceramic. Grinding is carried out using diamond, CBN or vitreous grinding grains.