APPARATUS FOR SENSING DROOPING STATES OF WAFER TRANSFER CASSETTE SLOT AND ROBOT ARM

摘要

PURPOSE: An apparatus for sensing drooping states of a wafer transfer cassette slot and a robot arm is provided to sense the drooping states of the wafer transfer cassette slot and the robot arm by detecting the drooping state of a wafer loaded into the wafer transfer cassette. CONSTITUTION: An apparatus for sensing drooping states of a wafer transfer cassette slot and a robot arm includes a light emitting unit(20), a light receiving unit(30), and a reading unit(80). The light emitting unit(20) is arranged at a front side of a cassette(10) for loading a wafer in order to irradiate the light to the inside of the cassette(10). The light receiving unit(30) is arranged at a rear side of the cassette(10) in order to receive the light of the light-emitting unit(20). The reading unit(80) reads the light received from the light receiving unit(30) to sense a drooping state of the wafer.