Method for manufacturing glass substrate of information recording medium
AssigneeHoya Corporation
InventorsYasuhiro Saito, Kazuishi Mitani, Tatsuro Umeyama, Koji Okuhata, Toshiaki Hashimoto
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Abstract
Provided is a method for manufacturing a glass substrate for an information recording medium, which is advantageous in that oozing of an alkali and deformation of a texture are suppressed. The glass substrate is chemically reinforced, and a texture is formed in the glass substrate, and then treated with a neutral or alkaline aqueous solution. In the texture forming step, the surface of the glass substrate is etched in a depth of 0.5 to 10 nm.
Claims27
A method for manufacturing a glass substrate for an information recording medium, the method comprising the steps of:
- forming a glass substrate in a disc form;
- chemically reinforcing the glass substrate;
- and
- etching a primary surface of the glass substrate in an average depth of 0.5 to 10 nm from the primary surface to form a texture in the primary surface.
A disc-shaped glass substrate for an information recording medium, which has a texture in which a ratio of a maximum peak height Rp to a root mean square roughness RMS is 15 or less.
A disc-shaped glass substrate for an information recording medium comprising:
- a first layer containing a first alkali metal having a relatively small ionic radius in a larger amount;
- a modified layer, formed on the first layer, containing a second alkali metal having a relatively large ionic radius in a larger amount;
- and
- a texture formed only in the modified layer.
Dependencies are inferred from the claim text.