MANUFACTURING METHOD OF GLASS SUBSTRATE FOR RECORDING MEDIUM, GLASS SUBSTRATE FOR RECORDING MEDIUM AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a glass substrate for a recording medium free from a fissure, a crack and deformation and having satisfactory strength. SOLUTION: In the manufacturing method of the glass substrate for the recording medium having a chemical strengthening step for bringing the glass substrate into contact with a chemical strengthening liquid and replacing alkali metal ions on the surface of the glass substrate with alkali metal ions contained in the chemical strengthening liquid and each having an ion diameter larger than that of the alkali metal ion on the surface of the glass substrate to perform chemical strengthening, the chemical strengthening step has a chemical strengthening liquid immersion step for immersing the glass substrate in the chemical strengthening liquid and a water immersion step for immersing the glass substrate taken out from the chemical strengthening liquid in water after the glass substrate is made to wait for 1 sec or longer in atmosphere. COPYRIGHT: (C)2008,JPO&INPIT