TREATMENT METHOD AND MANUFACTURING METHOD OF GLASS SUBSTRATE FOR MAGNETIC DISK, AND MAGNETIC DISK

• Main Authors: ETO NOBUYUKI, ISONO HIDEKI
• Format: Patent
• Language: English
• Published: 24.08.2006
• 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; METALLURGY; MINERAL OR SLAG WOOL; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

PROBLEM TO BE SOLVED: To provide a treatment method of a magnetic disk glass substrate for manufacturing the glass substrate suitable for the magnetic disk, or the like to be used in a magnetic disk device, such as an HDD, which does not cause a breakage with the lapse of time and has a high flexural strength, and to provide a magnetic disk using the glass substrate. SOLUTION: After mirror-polishing the glass substrate made of amorphous aluminosilicate glass containing lithium ions, the glass substrate is dipped into a treating agent of a sodium nitrate molten salt at 380°C for two hours as the first treatment, and after dipping the glass substrate into a treatment agent of a potassium nitrate molten salt at 380°C for two hours as the second treatment, the glass substrate for the magnetic disk is obtained after cleaning the glass substrate. A magnetic layer, or the like is formed on the glass substrate by an appropriate method, then the magnetic disk high in flexural strength and excellent in LUL durability is obtained. COPYRIGHT: (C)2006,JPO&NCIPI