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:
Nov. 05, 2002
Filed:
Dec. 28, 1999
Robert E. Steere, III, Boonton, NJ (US);
Colby Steere, Parsippany, NJ (US);
Accretech USA, Inc., Oakland, NJ (US);
Abstract
A wafer edge grinding or polishing machine is provided with a pair of chucks for engaging a wafer therebetween, a fixed reference surface and a sensor which is movable with a movable chuck. Measurements are made by the sensor relative to the fixed reference plane when the movable chuck is in engagement with the opposite chuck without a wafer therebetween in order to obtain a standard measurement value. With a wafer between the chucks, the sensor obtains an actual measurement value relative to the fixed reference surface. A calculator determines the difference between the standard and actual measurements values and displays the difference as the thickness of the wafer. Multiple sensors may be used to obtain multiples readings which are averaged by the calculator to obtain a thickness measurement.