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:
Apr. 07, 2009
Filed:
Feb. 17, 2005
Yoichi Kobane, Kuwana, JP;
Akira Fujii, Yokkaichi, JP;
Hideo Kamiya, Nagoya, JP;
Hiroaki Makino, Aichi, JP;
Yoichi Kobane, Kuwana, JP;
Akira Fujii, Yokkaichi, JP;
Hideo Kamiya, Nagoya, JP;
Hiroaki Makino, Aichi, JP;
Denso Corporation, Kariya, Aichi-Pref., JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-Shi, Aichi-Ken, JP;
Abstract
An object of the present invention is to provide a piezoelectric stack substantially free from deterioration in performance and having high reliability, and a production method thereof. A piezoelectric layercomprising PZT and an internal electrode layerare alternately stacked; the grain boundary-filling factor of a Pb-based glass in the crystal grain boundary of the piezoelectric layeris 95% or more; in producing a piezoelectric stackin which a piezoelectric layercomprising PZT and an internal electrode layerare alternately stacked, unfired sheets for the piezoelectric layerare stacked to produce an unfired stacked body, the unfired sheet containing Pb in excess of the stoichiometric ratio in PZT and having printed thereon an electrically conducting paste for the internal electrode layer, and the unfired stacked body is fired in an oxygen atmosphere having an oxygen concentration of 40 to 100 vol % such that the grain boundary-filling factor of a Pb-based glass in the crystal grain boundary inside the piezoelectric layeris 95% or more.