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. 13, 1991
Filed:
Jun. 12, 1990
Applicant:
Inventors:
Assignee:
Sumitomo Metal Mining Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C04B / ;
U.S. Cl.
CPC ...
501135 ; 501134 ; 501136 ; 264 66 ;
Abstract
A process for producing a dielectric ceramic comprising a firing step comprises the substeps of heating a calcined product rapidly up to a temperature of from 1,500.degree. to 1,700.degree. C. and thereafter sintering the product at the temperature, and heating the product thus heat-treated through said first heat-treating substep at about 1,200.degree. C. to 1,600.degree. C. for not less than 10 minutes. It is possible to prepare a dielectric ceramic with a desired temperature properties of the resonant frequency.