Investigations on Polisher Life in Ultra-high Pressure and Speed Polishing of Aluminum Type of Magnetic Disk Substrate (2nd Report)

Abstract

By using ultra-high pressure and speed polishing, the research aims to develop the ultra-high removal rate polishing technique under the ultra-smoothness polishing of magnetic disk substrate. In the report, the influence of polisher surface structure on polisher life is experimentally examined and discussed by comparing the change of removal rate with polishing process for two types of polisher surface structures. Polishing pressure ranges from 10kPa to 60kPa under the polishing speed of 1.5m/s. The polishing pressure of 10kPa and polishing speed of 1.5m/s are near the highest in the region of polishing conditions used generally at the present polishing operation. The surface structure of polishers used is single and double NAP layers. In case of the double layer polisher, only the first two steps, that is, the first transitional polishing process and the steady polishing process among the four steps which is found in the change of removal rate with polishing process for the single layer polisher are ascertained. The polisher life can not be found at the polishing pressure of 10kPa. In the ultra-high pressure condition of 60kPa, the removal rate for both the single and double layer polishers becomes about four times larger than that in the 10kPa. The polishing pressure has little influence on surface smoothness.