The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 13, 1988
Filed:
Apr. 17, 1986
John S Batchelder, Tarrytown, NY (US);
Raymond E Bonner, Yorktown Heights, NY (US);
Byron E Dom, North Salem, NY (US);
Robert S Jaffe, Shenorock, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and apparatus for automatic inspection of periodic patterns typically found on patterned silicon wafers, printed circuit board, and the like is disclosed herein. The method comprises an inspection algorithm of two parts: a low-level algorithm and a higher level algorithm which includes, therein the operation of the low-level algorithm. The low-level algorithm utilizes the known periodicity of the pattern to find defects by comparing identical cells in the periodic array. The high-level algorithm comprises applying the low-level algorithm, some number of times (N) in succession on the image. An accumulator image is formed by adding the results of the low-level algorithm to create a separate image array where the pixels relate to the number of times that the pixel in the original image was detected as defective by the low-level algorithm. The apparatus for implementing the above method comprises a parallel/pipeline architecture for high speed processing and RAM LUT's to implement a plurality of subtract and compare functions.