Glass substrate for magnetic disk and method for manufacturing
AssigneeNippon Sheet Glass Co., Ltd.
InventorsHiroshi Ikeda, Yoshihiro Matsuno, Takeo Watanabe
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Abstract
A method of manufacturing a glass substrate for a magnetic disk. The method includes the step of scrub-etching the glass substrate using a pad in the presence of an acid treatment solution. As the acid treatment solution, hydrofluoric acid is used in a range of 0.01 to 1 wt %. The scrub-etching step is performed at temperatures ranging from 5 to 60° C. for 1 second to 300 seconds. The method produces a substrate that is substantially free of asperity.
Claims29
A method for manufacturing a glass substrate for a magnetic disk, comprising texturing a polished surface of the glass substrate material to form a textured surface having reduced occurrence of asperity than the polished surface and having an average surface roughness Ra in a range of from 0.4 nm to 3 nm and a ratio of a 10-points mean roughness Rz to the average surface roughness Ra of 14 or less, the texturing including scrub-etching a surface of the glass substrate material using a scrubbing pad in the presence of an acid treatment solution.
A method of manufacturing a substrate for a magnetic disk, comprising forming a fine texture, having an average surface roughness Ra in a range between 0.4 and 3.0 nm and a ratio of a 10-points mean roughness Rz to the average surface roughness Ra of 14 or less, on a substrate made of an inorganic material or on a substrate having an alloy film on a surface thereof, wherein the forming step includes the repeatedly performing an immersion process or scrub process several times using an acid solution under different treatment conditions.
Dependencies are inferred from the claim text.