GLASS SUBSTRATE FOR INFORMATION-RECORDING MEDIUM, INFORMATION-RECORDING MEDIUM, AND THEIR MANUFACTURING METHODS

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass substrate for an information-recording medium by which the glass substrate having a desired shape of the outer peripheral edge part is obtained after the glass substrate is tempered chemically. SOLUTION: This method for manufacturing the glass substrate for the information-recording medium comprises a step to grasp the relationship between the changes of the shapes of the outer peripheral edge part and/or the inner peripheral edge part of the glass substrate to be caused by chemical tempering treatment and the chemical tempering conditions, a step to decide the shapes of the outer peripheral edge part and/or the inner peripheral edge part before the chemical tempering treatment by anticipating their shapes to be changed by the chemical tempering treatment and prepare the glass substrate 1 having the decided shapes before the chemical tempering treatment and a step to subject the prepared substrate 1 to the chemical tempering treatment to obtain the glass substrate having the desired shapes after the chemical tempering treatment.