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:
Dec. 15, 1987
Filed:
Apr. 17, 1986
Applicant:
Inventors:
Frederick P Layman, Fremont, CA (US);
Michael J Kuhlman, Fremont, CA (US);
Assignee:
Varian Associates, Inc., Palo Alto, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
250561 ; 2502 / ;
Abstract
In order to compensate for worn or distorted wafer cassettes and missing wafers, the cassette of wafers is scanned through a beam. The timing of the interruptions of the beam is used to inventory the wafers present and measure the exact position of each wafer relative to the base of the cassette.