GLASS SUBSTRATE FOR MAGNETIC DISK AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To enhance the reliability of a glass substrate especially under the circumstance of a high temperature and a high humidity by preventing the elution of alkali ions from the surface of the glass substrate for magnetic disk. SOLUTION: The glass substrate for magnetic disk is immersed in warm water at a temperature of 50 deg.C to 100 deg.C for 24 hr to 100 hr to form the surface of the glass substrate nearly free from the elution of the alkali ions. The immersion time can be reduced up to 30 min-24 hr by controlling the temperature of the warm water to be at a temperature of 120 deg.C to 180 deg.C using a pressure- resistant container.