Method for lapping semiconductor wafers, involves reducing rotational lapping speeds gradually to zero

摘要

A method for simultaneous two-sided lapping of semiconductor wafers which lie in rotor discs set in rotation by means of annular outer and inner drive gears. At the end of lapping the rotationally speeds of the outer annular gear and of the inner annular gear are gradually reduced to zero. From the point in time at which the speed of the outer annular gear starts to be reduced to stand-still, the upper lapping disc, the lower lapping disc and the inner annular gear and the outer annular gear rotate in the same direction.