GLASS SUBSTRATE FOR MAGNETIC DISK AND METHOD FOR MANUFACTURING GLASS SUBSTRATE FOR MAGNETIC DISK

• Main Authors: SATO TAKASHI, ISONO HIDEKI, TANINO HIDEKAZU, MURAKAMI AKIRA, SATO MASAMUNE
• Format: Patent
• Language: English
• Published: 20.02.2014
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; GLASS; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; JOINING GLASS TO GLASS OR OTHER MATERIALS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

A method for manufacturing a glass substrate for magnetic disk is provided. The method includes a forming process of press-forming a lump of molten glass using a pair of dies, wherein in the forming process, the cooling rate of the molten glass during pressing is controlled so that a first compressive stress layer is formed on a pair of principal faces of a glass blank that is press formed, and the method includes a chemically strengthening process for forming a second compressive stress layer on a pair of principal faces of a glass substrate formed using the glass blank after the forming process.