Controls for semiconductor wafer orientor

Abstract From the Canadian patent

This specification deals with electro-optic controls for stopping and orienting of a semiconductor wafer being transported along a track on an air film. At one or more locations along the track the characteristics of the air film are changed by electronic controls responding to optical pickups sensing the position and orientation of a semiconductor wafer entering the particular location on the air film to first stop the wafer in the general proximity of the location then, center the wafer in the location and after the wafer is centered quickly rotate the wafer until it assumes the desired orientation. All this is done without edge contact of the wafer by any solid objects.