METHOD OF MANUFACTURING GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an efficient method for manufacturing a glass substrate for a magnetic recording medium which is applicable to a magnetic disk unit in which the floating amount of a magnetic head is about 50 nm. SOLUTION: When the main surface of a chemically reinforced glass substrate is polished, the average value of the differences between the maximum and the minimum in the unevenness per 12μm square of each polished surface, measured by an atomic force microscope, is controlled to be >=8 and <=20 nm by adjusting the thickness reduced by polishing of the glass substrate to be >=0.05 and <=0.7μm for each polishing surface.