摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a glass substrate for a magnetic disk especially useful when a magnetic disk wherein a magnetic head floats and flies at a low floating height of≤10 nm is manufactured, and to provide a manufacturing method of the magnetic disk using the glass substrate. SOLUTION: In the manufacturing method of the glass substrate for the magnetic disk including mirror polishing and washing of the glass substrate, an abrasive material containing≤5 wt.% fluorine content and consisting essentially of a rare earth oxide is supplied to the glass substrate, the surface of the glass substrate is mirror polished by relatively transferring a polishing cloth and the glass substrate and then the glass substrate is brought into contact with a washing liquid containing ascorbic acid, fluorine ions and≥3 wt.% sulfuric acid to dissolve and remove the abrasive material. The concentration of the ascorbic acid and fluorine ion content contained in the washing liquid are specified to be≥0.1 wt.% and 1 to 40 ppm, respectively. At least a magnetic layer is film-deposited on the obtained glass substrate for the magnetic disk to manufacture the magnetic disk. COPYRIGHT: (C)2006,JPO&NCIPI
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