Z-axis monitoring apparatus for robot blade

摘要

An apparatus for monitoring the Z-axis position of a transfer blade on a wafer transfer robot which transfers wafers among multiple chambers in a semiconductor fabrication facility. The invention comprises a CCD laser displacement sensor which measures the height or Z-axis position of the transfer blade and generates an analog voltage the value of which depends on the height of the transfer blade. An analog controller connected to the CCD laser displacement sensor converts the analog voltage signal to physical distance, which may be displayed on an LCD display on the analog controller. The analog controller may further be connected to a robot controller through an interface PCB, in which case a voltage signal corresponding to an abnormal position of the transfer blade is transmitted to the robot controller and the wafer transfer operation is terminated.