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:
Nov. 30, 1999
Filed:
Nov. 07, 1996
Applicant:
Inventors:
Kohichi Hayashi, Shiga-ken, JP;
Akira Ando, Ohmihachiman, JP;
Akira Nagai, Tsuzuki-gun, JP;
Hiroshi Takagi, Otsu, JP;
Kiyoshi Hase, Ishikawa-ken, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
252 / ; 501134 ;
Abstract
The present invention provides a piezoelectric ceramic having a low mechanical quality coefficient Qm and excellent heat resistance, for example, a piezoelectric ceramic for a filter element which can be applied to surface mounting. The piezoelectric ceramic contains at least a composite oxide of lead, zirconium and titanium, and oxides of manganese, silicon and boron, the concentration of the manganese oxide present in the crystal gain boundary being higher than that in crystal grains of the piezoelectric ceramic.