Investigations on Polisher Life in Ultra-high Pressure and Speed Polishing of Aluminum Type of Magnetic Disk Substrate (1st 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 aluminum type of magnetic disk substrate. In the report, the change of removal rate with polishing process using colloidal silica abrasives is experimentally examined and polisher life is discussed. Polishing pressure and speed range from 10kPa to 60kPa and from 1.5m/s to 9m/s, respectively. The polishing pressure of 10kPa and polishing speed of 1.5m/s are near the highest region of polishing conditions used generally at present. The polisher used is a suede-type one consisted of single nap layer. In the polishing conditions used generally at present, the removal rate decreases through polishing process of four steps. Second step is the steady polishing process. Fourth step is the process of polisher life in which the removal rate is extremely small. First step and third step are the transient polishing processes from initial polishing process to steady state process and from steady state process to polisher life. In the ultra-high pressure and speed polishing, on the other hand, the third and fourth step can not be found for long polishing process. The change of removal rate with polishing process has little influence on surface smoothness.