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:
Aug. 17, 1993
Filed:
May. 29, 1992
Warren K Harwood, Vancouver, WA (US);
Paul A Tervo, Vancouver, WA (US);
Richard H Warner, Portland, OR (US);
Cascade Microtech, Inc., Beaverton, OR (US);
Abstract
A wafer probe station has a wafer-supporting vacuum chuck, together with one or more substrate-supporting auxiliary vacuum chucks having independent vacuum controls for mounting contact substrates and calibration substrates simultaneously with the wafer. A detachable interconnection of the various chucks enables independent replacement of each chuck to accommodate various different chuck types, and also permits the elevations of the respective chuck surfaces to be adjusted relative to each other to compensate for differences in thicknesses between the wafer substrate and the calibration or contact substrates. The invention is especially useful in wafer probe stations equipped with enclosures for controlled-environment testing where a large variety of different wafer chucks must be readily interchangeable for testing under different conditions.