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. 29, 1995
Filed:
Mar. 21, 1994
Osamu Ishii, Kouza, JP;
Toyo Communication Equipment Co., Ltd., Kanagawa, JP;
Abstract
A method for preparing ultrathin piezoelectric resonator plates having an ultrathin vibrating portion enclosed by a thick periphery portion, comprising a forming process which forms a plurality of depressions in one side of a wafer of a piezoelectric material to form ultrathin vibrating portions as the bottom wall of each depression and a trimming process which trims the thickness of each vibrating portion by etching to adjust the resonance frequency, characterized by bonding a comparatively thick plate with a plurality of holes formed at the positions corresponding to the depressions in the wafer to the depressed side of the wafer or forming a layer with a plurality of holes formed at the positions corresponding to the depressions in the wafer over the depressed side of the wafer, and putting an etching liquid into the depressions through the holes in the thick plate or layer. By this method, excessive or incomplete trimming in the trimming process can be prevented and hence the yield rate of product increases.