GLASS SUBSTRATE FOR MAGNETIC DISK AND MANUFACTURING METHOD THEREOF

摘要

The present invention provides a method for efficiently manufacturing a glass substrate for magnetic disk having good accuracy of a surface irregularity and an impact resistance. The method includes the steps of: performing press forming to molten glass to prepare a sheet glass material, the sheet glass material having a roughness of the principal surface of 0.01 μm or less and target flatness of a glass substrate for magnetic disk; chemically strengthening the sheet glass material by dipping the sheet glass material in a chemically strengthening salt, thereby preparing a disk substrate; polishing the principal surfaces of the disk substrate. A thickness of the sheet glass material prepared in the press forming step is larger than a target thickness of the glass substrate for magnetic disk by a polishing quantity of the principal surface polishing step.

主权项

1. A manufacturing method of a glass substrate for a magnetic disk, comprising:
forming a sheet glass material by press forming a lump of molten glass while sandwiching the lump from opposing sides using surfaces of a pair of dies set at approximately the same temperature, such that the surfaces of the pair of dies are brought into close contact at approximately identical timing; and polishing a principal surface of the sheet glass material by pressing a polishing pad against the principal surface of the sheet glass material while supplying a polishing solution including a polishing material between the sheet glass material and the polishing pad, and relatively moving the sheet glass material and the polishing pad.