METHOD FOR MANUFACTURING GLASS SUBSTRATE FOR INFORMATION RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To manufacture a glass substrate for information recording medium having excellent flatness and cleanness. SOLUTION: A glass substrate 1 consisting of aluminosilicate-based glass material or the like is subjected to precision polishing treatment in a polishing stage 2 and the resultant glass substrate is washed by using an acid aqueous solution consisting of hydrofluoric acid and the like and an alkaline aqueous solution consisting of sodium hydroxide and the like in a successive first washing stage 3. The resultant glass substrate is subjected to heat treatment, preferably concurrently including chemically strengthening treatment in a fused salt, in a heating stage 4 to relax the permanent set formed on the surface of the glass substrate 1 and then the glass substrate 1 is washed again by using an acid aqueous solution 5a and an alkaline aqueous solution 5b in a second washing stage 5.