摘要 |
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/cm2 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/cm2 or less, preferably 50 g/cm2 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/cm2 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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