Glass substrate for magnetic disk and manufacturing method thereof
US9085479B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2014 |
| Grant date | Jul 21, 2015 |
| Priority date | — |
| Expiry date | Apr 17, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B11/125
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.