MANUFACTURING METHODS OF GLASS SUBSTRATE FOR MAGNETIC DISK AND OF MAGNETIC DISK

文件类型：PDF文档
文件大小：81K
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