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:
Jun. 16, 1998
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;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
Piezoelectric ceramics whose mechanical quality factor Qm is small and which has an excellent heat resistance, e.g. piezoelectric ceramics for filtering elements whose group delay time characteristic is flat, phase distortion is small and which can be accommodated to surface mounting, and a method for stably producing it are provided. Manganese oxide and lead oxide are caused to coexist in high concentration in grain boundary parts of the piezoelectric ceramics containing composite oxides of at least lead, zirconium and titanium as compared to intra-crystal grains of the piezoelectric ceramics. It is manufactured by treating the piezoelectric ceramics by heat after adhering manganese and lead compounds on the surface thereof to diffuse the oxides in the grain boundary parts of the piezoelectric ceramics.