Patent ID: 8526709
Filing Date: 2013-09-03
Classification: G01B,G01N

Abstract:
1. A method for determining physical placement data for a plurality of wafers, said plurality of wafers being disposed on a plurality of parallel sets of fingers using a linear CCD array and a memory device and a logic module, comprising: obtaining raw CCD array data, said obtaining including serially clocking data from pixels of said linear CCD array into memory cells of said memory device; ascertaining, using said logic module and said memory device, pixel transition data from at least one of said raw CCD array data and filtered CCD array data, said pixel transition data including a number of transitions between adjacent pixel pairs and locations of said transitions; ascertaining, using said logic module and said pixel transition data, whether at least one of an upper edge error, a lower edge error, a wafer thickness error, and transition-per-slot error exists; and if said at least one of said upper edge error, said lower edge error, said wafer thickness error, and said transition-per-slot error exists, generating an error signal.