BASE MATERIAL FOR GLASS SUBSTRATE FOR INFORMATION RECORDING, GLASS SUBSTRATE FOR INFORMATION RECORDING AND MANUFACTURING METHOD THEREFOR, MAGNETIC RECORDING MEDIUM, AND HARD DISK

摘要

PROBLEM TO BE SOLVED: To provide a base material for a glass substrate for information recording which is used mainly for a hard disk, and to provide a glass substrate for information recording, a manufacturing method therefor, a magnetic recording medium which has a magnetic film on the top surface of the glass substrate for information recording, and a hard disk with the same incorporated. SOLUTION: The base material for the glass substrate for information recording is formed by gradually cooling the base material by cooling facilities while adjusting the temperature falling speed of the base material so that maximum compressive stress of 1 to 10 MPa is applied to the top surface of the base material after the base material is molded by press molding. COPYRIGHT: (C)2005,JPO&NCIPI