The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 1999
Filed:
Aug. 22, 1997
Tomoya Utashiro, Oyama, JP;
Showa Aluminum Corporation, Osaka, JP;
Abstract
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.