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. 17, 1992
Filed:
Dec. 17, 1991
Hideyuki Kanai, Kawasaki, JP;
Yohachi Yamashita, Yokohama, JP;
Osamu Furukawa, Sagamihara, JP;
Kumi Okuwada, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A ceramic capacitor includes at least two opposing electrodes, and a dielectric ceramic composition arranged between the electrodes, wherein the ceramic composition is represented by a formula (Pb.sub.1-x Ae.sub.x) (Zr.sub.1-y Ti.sub.y)O.sub.3 (wherein x represents 0.15 to 0.90, y represents 0 to 0.80, and Ae represents at least one type of an element selected from the group consisting of Ca and Sr), and has a composition in which assuming that the total number of moles of elements constituting a site A consisting of Pb and Ae is (A) and that the total number of moles of elements constituting a site B consisting of Zr and Ti is (B), (A)/(B) is 1.00 or less. The site A of the dielectric ceramic composition may be partially substituted with Ba. The dielectric ceramic composition may be obtained by adding Nb, Cu, Bi, Mn, Co, Ag, Si, Ta, Mg, Zn, W and/or Ni to a composition which is represented by a formula (Pb.sub.1-x Ae.sub.x) (Zr.sub.1-y Ti.sub.y)O.sub.3 (wherein x represents 0.15 to 0.90, y represents 0 to 0.80, and Ae represents at least one type of an element selected from the group consisting of Ca, Sr, and Ba), and in which assuming that the total number of moles of elements constituting a site A consisting of Pb and Ae is (A) and that the total number of moles of elements constituting a site B consisting of Zr and Ti is (B), (A)/(B) is 1.00 or less. The dielectric ceramic composition is preferably formed by using a powder synthesized by a hydrothermal synthesis as a material, and its grain size is preferably 3 .mu.m or less.