Wafer edge detection system

摘要: A noncontact gauge for edge detecting of semiconductor wafers in a test rig which indexes between circuits the wafer to provide functional tests upon them. The includes capacitive probe having an elongated finger that is bent into position few thousands inch above when positioned circuit order detect whether system, indexing from row and column matrix integrated chips wafer, has moved one or other water. detection system operates with conventional systems raise lower index next matrix. When down position, circuitry, automatic compensation changes modes calibrate detector predetermined capacitance representative sensed by out proximity. Additionally, circuitry particular energization probe, de-energized portion period being tested eliminate interference excitation check-out circuitry.