APPARATUS FOR MEASURING DISTANCE OF WAFER TRANSFER UNIT USED IN WET CLEANING SYSTEM

摘要

PURPOSE: An apparatus for measuring a distance of a wafer transfer unit used in a wet cleaning system is provided to prevent an accident caused by malfunction of the wafer transfer unit from an error of a horizontal motor, by measuring the distance of the wafer transfer unit while using a distance measuring unit. CONSTITUTION: A horizontal guide member(24) is guided in a horizontal direction of the wafer transfer unit(20) having a reflecting member(32) at its side while an assembly block(31) is assembled in an end of the horizontal guide member. The distance measuring unit(33) is assembled on the plane of the assembly block assembled in the end of the horizontal guide member. The distance measuring unit radiates a beam to the reflecting member assembled in the side of the wafer transfer unit guided by the horizontal guide member and receives a reflected beam reflected from the reflecting member so that the distance measuring unit detects the horizontal position of the wafer transfer unit to output a horizontal position signal.