| 摘要 |
PURPOSE:To maintain a high quality by increasing the amount of slurry supply automatically when a thickness a little greater than the final wafer thickness is detected, and thereby reducing the production cost. CONSTITUTION:The point of time when a wafer 4 has attained a thickness a certain extent greater than the final value is sensed by a regular dimensioning device 15 so as to emit an Immediate Before signal P, and the point of time when the wafer 4 has attained the final thickness is sensed to emit an End signal Q. The revolving speed of a slurry pump is changed by reference to the Immediate Before signal give by said regular dimensioning device 15 so as to increase the amount of abrasive grain slurry. Accordingly abrasive grain slurry can be reduced greatly to serve for suppression of the production cost. Besides it, slurry is increased compared with the specific time, so that there is little fear of generation of flaw or contamination on the surface of wafer, which may contribute to maintenance of the wafer 4 quality. |
