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:
Mar. 26, 1991
Filed:
Dec. 01, 1988
Applicant:
Inventor:
Peter M Seitz, Sellenburen, CH;
Assignee:
Harris Semiconductor Patents, Inc., Melbourne, FL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06K / ;
U.S. Cl.
CPC ...
382 22 ; 356376 ; 358106 ; 382-8 ;
Abstract
By comparing the distorted image of an edge pattern, such as a checker board pattern, reflected from the surface of a work piece, such as a silicon wafer, and received by a solid state television camera, with a similar image, reflected from the optically flat surface of a calibration piece substituted for the work piece, surface height irregularities, such as warpage, of the work piece can be measured with a high sensitivity and a large dynamic range at relatively low cost.