| 摘要 |
PURPOSE: To provide a glass substrate for magnetic disks free from projections, such as linkage bumps, by subjecting a substrate which is subjected to a polishing treatment to remove microcracks or to substantially decrease the number of the microcracks to a chemical etching treatment. CONSTITUTION: The glass substrate surface from which the microcracks are removed by the prepolishing treatment is subjected to the treatment to bring an aq. soln. contg. a fluorine compd. into contact therewith or bringing gas contg. hydrogen fluoride into contact therewith as the chemical etching treatment. As a result, fine ruggedness (texture) is formed on the glass surface. The glass substrate for the magnetic disks in which the max. height Rmax of the surface roughness by the ruggedness is substantially <=700μm at a reference length 25μm and is substantially >=50μm at a reference length 50μm and the linkage bumps having the height exceeding about 500μm do not substantially exist is obtd.
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