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:
Jul. 25, 1978
Filed:
Jan. 30, 1976
Applicant:
Inventors:
Glenn N Howatt, Metuchen, NJ (US);
Murray Leonard, Mayfield Village, OH (US);
Assignee:
Vernitron Corporation, Bedford, OH (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ; H03H / ; H03H / ; H01L / ;
U.S. Cl.
CPC ...
333 72 ; 29 2535 ; 310340 ;
Abstract
In the manufacture of wave filters, such as FM filters, polarized piezoelectrically responsive wafers are provided, temporarily, on the active regions thereof, with a removable material. Subsequent to the encapsulation of the wafer by a protective but porous coating, the filter is heated and the removable material sublimates through the porous coating establishing a wafer surface substantially free of residual impurities and leaving an uninterrupted cavity between the wafer and the coating in the active regions. The preferred sublimatable material is paradichlorobenzene.