Method of polishing memory disk substrate

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United States of America Patent

PATENT NO 5902172
SERIAL NO

08929350

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Abstract

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In a method of polishing a Ni--P plated aluminum alloy memory disk substrate, the present invention provides a polishing method which can efficiently form a good polished surface having slight polishing flaws, restrain the generation of a defect other than the polishing flaws and has a high productivity. That is, in the method according to the present invention, an alumina abrasive grain is used as a polishing compound. The present invention solves the problem by dividing the polishing process into two steps. In the first step, a first polishing is performed in which the main work pressure is 80 g/cm.sup.2 or more and the amount of polishing is 1 .mu.m or more. A second polishing is then peformed in which the main work pressure is 80 g/cm.sup.2 or less, preferably 50 g/cm.sup.2 or less, and the amount of one-sided polishing is 2 .mu.m or less. A final finish polishing is performed for 10-60 seconds prior to the completion of the second polishing step in which the main work pressure is 30 g/cm.sup.2 or less and the average relative velocity of the substrate and polishing cloth is reduced to 50 cm/s or less. In the present invention, the supply of polishing slurry and cleaning solution is preferably stopped during the final finish polishing step.

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Patent Owner(s)

Patent OwnerAddress
SHOWA DENKO K K13-9 SHIBA DAIMON 1-CHOME MINATO-KU TOKYO 1058518 ?1058518

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Utashiro, Tomoya Oyama, JP 12 108

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