SURFACE GRINDING MACHINE

摘要

SO2-47448M/MS/87 A surface grinding-machine comprises a wheel head vertically movably supported; a cup-shaped diamond wheel supported by a rotatable wheel shaft at one end of the wheel head and having an abrasive grain layer of Young's modulus (10 - 15) x 104 kgf/cm2 at the lower end of the wheel; a wheel shaft driving motor for rotating the cupshaped diamond wheel supported by the wheel head; a servomotor for vertically moving the wheel head; a suitable number of chuck tables for fixing the surface of a III-V group compound semiconductor wafer on which elements have been fabricated; an index table for rotatably supporting the chuck tables a chuck table driving motor for turning the chuck tables; a main shaft motor current analysis circuit for detecting the current value of the wheel shaft driving motor; a main shaft rotation number analysis circuit for detecting the number of rotations of the wheel shaft driving motor, and a feed speed control circuit for controlling the servomotor in such a manner as to decrese the feed speed when the grinding resistance is greater than a predetermined resistance value, and increase the feed speed when the grinding resistance is smaller than the predetermined resistance value.