Glass substrate for information-recording medium and manufacturing method of the glass substrate
AssigneeHoya Corporation
InventorHisanori Suzuki
Life of this patent
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Abstract
A glass substrate for a highly reliable information-recording medium in which stiction is reduced because of a small diameter of each protuberance, the CSS durability is good, and a head is prevented from being damaged, is provided. A method capable of stably manufacturing such a glass substrate for a highly reliable information-recording medium with a good controllability, is also provided. In a method of making protuberances 1a by irradiation to a glass substrate 1 with a laser light, a glass substrate having a coefficient of thermal expansion of 75×10−7/° C. or more is used as the glass substrate 1.
Claims10
A glass substrate for an information-recording medium, in a surface of which substrate protuberances are made at a predetermined area by irradiation with a laser light, wherein the coefficient of thermal expansion of said glass substrate is not less than 75×10−7/° C.
A glass substrate for an information-recording medium, in a surface of which substrate protuberances are made at a predetermined area by irradiation with a laser light, wherein the coefficient of thermal expansion of said glass substrate is not less than 90×10−7/° C.
A glass substrate for an information-recording medium, in a surface of which substrate protuberances are made at a predetermined area by irradiation with a laser light, wherein the coefficient of thermal expansion of said glass substrate is not less than 75×10−7/° C. and not more than 130×10−7/° C.
A glass substrate for an information-recording medium, in a surface of which substrate protuberances are made at a predetermined area by irradiation with a laser light, wherein the coefficient of thermal expansion of said glass substrate is not less than 90×10−7/° C. and not more than 130×10−7/° C.
A manufacturing method of a glass substrate for an information-recording medium, wherein protuberances are made at a predetermined area of a surface of a glass substrate having a coefficient of thermal expansion of 75×10−7/° C. or more, by irradiation with a laser light.
Dependencies are inferred from the claim text.