GLASS SUBSTRATE FOR RECORDING MEDIUM, RECORDING MEDIUM AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a glass substrate for recording medium having sufficient reliability as a substrate for recording medium without ant anxiety of trouble occurrence due to a crack or the like even when it is used for a linger period than its service life and a recording medium using this glass substrate. SOLUTION: This medium is a glass substrate for recording medium having a compressive stress layer and a tensile stress layer formed in turn in the direction of its thickness. In the case that the distribution value of the tensile stress in the tensile stress layer draws a convex peal curve in the tensile stress- increasing direction near the compressive stress layer, the maximum value of the tensile stress at the peak is set to a value less than the standard design value capable of suppressing destruction due to a crack.