Sheet glass flattening method, method of manufacturing glass substrate for an information recording disk using flattened glass, method of manufacturing a magnetic recording disk using glass substrate, and magnetic recording medium
US5654057A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1995 |
| Grant date | Aug 5, 1997 |
| Priority date | — |
| Expiry date | Dec 27, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/315
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A glass substrate manufacturing method advantageously applicable to magnetic recording disk glass substrates, LCD glass substrates, photomask glass substrates, or optical memory glass substrates. This method includes the steps of forming a film of a solution on at least a principal surface of a sheet glass formed using a down-drawing method, the solution containing a water soluble inorganic material and a surface-active agent; sandwiching both sides of a single sheet glass on which the film is formed or of a laminated structure of plural sheet glasses with a densified sheet with a high flatness to pressure the single glass or laminated structure; and heating and annealing the single sheet glass or laminated structure to flatten the same. The end side of the flatten glass substrate is treated with a treating solution containing a hydrofluosilicic acid. The glass substrate is formed by chemically strengthen a glass substrate by immersing the glass substrate in a chemical reinforcement solution heated and then ion exchanging ions on the surface-layer of the glass substrate with ions in the chemical reinforcement solution; pulling up the substrate from the chemical reinforcement soluti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.