Substrate for information recording media
AssigneeNippon Sheet Glass Co., Ltd.
InventorsYasuhiro Saito, Kazuishi Mitani, Yoshihiro Matsuno, Tatsuro Umeyama, Kazuaki Kanai
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Abstract
A substrate for information recording media is disclosed which has optimized shapes of surface recesses and protrusions and thereby contributes to a reduction in flying height and causes neither head crushing nor thermal asperities. The substrate for information recording media has surface recesses and protrusions wherein the height thereof at a contact proportion for the recesses and protrusions of 0.4% is from 2 to 7 nm when the height of the recesses and protrusions at a contact proportion therefor of 50% is taken as a base. The contact proportion is a value based on the bearing ratio determined with an atomic force microscope.
Claims8
A substrate for information recording media which has surface recesses and protrusions wherein the height thereof at a contact proportion for the recesses and protrusions of 0.4% as determined with an atomic force microscope (AFM) is from 2 to 7 nm when the height of the recesses and protrusions at a contact proportion therefor of 50% is taken as a base.
A process for producing a substrate for information recording media which comprises immersing an information recording medium substrate comprising a glass or crystallized glass as the base material in an acid and an aqueous alkali solution to thereby form a substrate for information recording media which has surface recesses and protrusions wherein the height thereof at a contact proportion for the recesses and protrusions of 0.4% as determined with an atomic force microscope (AFM) is from 2 to 7 nm when the height of the recesses protrusions at a contact proportion therefor of 50% is taken a base.
Dependencies are inferred from the claim text.