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:
Apr. 19, 1977
Filed:
Aug. 22, 1975
Applicant:
Inventors:
Barry M Singer, New York, NY (US);
Joseph J Lalak, Briarcliff Manor, NY (US);
Assignee:
North American Philips Corporation, New York, NY (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C23F / ;
U.S. Cl.
CPC ...
156626 ; 156345 ; 156654 ; 350 97 ; 356161 ;
Abstract
A method of reducing the thickness of a wafer of fragile material, e.g. pyroelectric material, by placing the wafer, supported only at its rim, in a holder filled with a non-corrosive liquid. The holder with the exposed surface of wafer is placed in an etch bath to reduce the thickness of the wafer. The wafer is removed from the etch bath, without removing it from the holder, to measure its thickness, using its index of refraction, which is facilitated by the presence of a bubble in the non-corrosive liquid.