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:
Jan. 24, 2006
Filed:
Feb. 12, 2004
Takeshi Senoo, Anjo, JP;
Nozomu Okumura, Nagoya, JP;
Yasuhiro Suzuki, Nagoya, JP;
Isao Mizuno, Chiryu, JP;
Akira Fujii, Toyoake, JP;
Takeshi Senoo, Anjo, JP;
Nozomu Okumura, Nagoya, JP;
Yasuhiro Suzuki, Nagoya, JP;
Isao Mizuno, Chiryu, JP;
Akira Fujii, Toyoake, JP;
Denso Corporation, Kariya, JP;
Abstract
A stacked piezoelectric device, which is inexpensive and excellent in electric transmission efficiency and little deterioration of strength of an internal electrode layer, is provided by having an internal electrode layer containing not less than 50 percent by weight of Cu element, and not more than 5 percent of a pore occurrence expressed by (B/A)×100 (%) wherein A is an area of an interface between the internal electrode layer and the piezoelectric layer and B is a sum of areas of pores which appear in the interface and have a diameter of not less than 0.1 micrometers. Preferably, a surface roughness Ra of the interface of the piezoelectric layer contacting the internal electrode layer is not more than 0.5 C (μm) wherein C is a thickness of the internal electrode layer in micrometers. The piezoelectric material constituting the piezoelectric layer preferably comprises PZT which is a Pb(Zr,Ti)O-based oxide having a perovskite structure.