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:
Oct. 12, 1999
Filed:
Oct. 07, 1996
Kiyoshi Hase, Ishikawa-ken, JP;
Hiroshi Takagi, Ohtsu, JP;
Akira Ando, Ohmihachiman, JP;
Akira Nagai, Tsuzuki-gun, JP;
Yu Tokuda, Muko, JP;
Koichi Hayashi, Shiga-ken, JP;
Abstract
There is provided a piezoelectric ceramic having a small mechanical factor of merit Qm and excellent heat-resisting properties, e.g., a piezoelectric ceramic for filter elements which is compatible with surface mounting and a method of manufacturing the same in a large amount and in a stable manner. There is provided a piezoelectric ceramic which is a composite oxide of at least lead, zirconium and titanium, wherein an oxide of manganese exists in a grain boundary layer in a density higher than that in a crystal grain of the piezoelectric ceramic and a glass phase exists in the grain boundary layer. It is manufactured by depositing a manganese compound and a glass material on the surface of a piezoelectric ceramic comprising a composite oxide of at least lead, zirconium and titanium and by performing thermal processing thereafter to diffuse the deposited substance in a grain boundary portion of the piezoelectric ceramic.