Wafer lapping device and contol method thereof

Abstract

A wafer lapping device may include a lower platen, an upper platen disposed on the lower platen in conjunction with the lower platen to lap a wafer, a cylinder configured to move the upper platen up and down via a rod, a detection target part configured to descend together with the upper platen, a plurality of position sensors configured to detect the detection target part that descends together with the upper platen to detect a descending position of the upper platen, a displacement sensor configured to detects the detection target part that descends together with the upper platen to detect a descending displacement of the upper platen, and a controller configured to control a descending speed of the upper platen based on the descending displacement of the upper platen and the descending position of the upper platen.

Dependencies are inferred from the claim text.