Patent ID: 6275742
Filing Date: 2001-08-14
Classification: H01L,Y10S

Abstract:
In a system for manipulating a series of disk like elements so that each element can be transported separately by a robot having an articulated two leg arm and an end effector to a station in a precise, predetermined orientation and alignment with respect to a reference fiducial on the element edge and the geometric center of the element, said system comprising:(a) a machine controller;(b) a rotary vacuum chuck for supporting an element and having a motor for driving said chuck connected to said controller;(c) an alignment device including an elongated light source which is above and extends across the outer edge of said element held on said chuck so as to produce a shadow image of an edge of said element;(d) an elongated sensor means located below said light source and the outer edge of said element and positioned to receive said shadow image;(e) means for processing the output from said sensor means to produce quadrature signal data relative to the actual position of the edge of said element;(f) means in said controller for synchronizing quadrature signals from said chuck motor and said sensor means for determining the location of said fiducial on said element and its geometric center relative to said chuck; and(g) optical means between said light source and said sensor means for optimizing the demarcation between light and shadow on said sensor means, wherein said optical means comprises first and second pairs of plano-convex lens which are spaced apart between said light source and said sensor means.