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:
Sep. 06, 1983
Filed:
Oct. 02, 1980
Haruhumi Mandai, Nagaokakyo, JP;
Kunitaro Nishimura, Youkaichi, JP;
Masami Yamaguchi, Nagaokakyo, JP;
Abstract
A boundary layer type semiconducting ceramic capacitor with high capacitance is disclosed. The capacitor comprises a semiconducting ceramic body in which grain boundaries on crystal grains of the semiconducting ceramic body are insulated, characterized in that said semiconducting ceramic body has a composition consisting essentially of 98.1 to 99.88 mole % of a main component (Sr.sub.1-x Ba.sub.x)Tio.sub.3 or (Sr.sub.1-x Ba.sub.x)TiO.sub.3 modified with a titanete and/or a zirconate, wherein x is a mole fraction of Ba and takes a value ranging from 0.30 to 0.50, and 0.1 to 1.0 mole % of at least one semiconductorizing agent selected from the group consisting of rare earth elements, Nb, Ta and W, and that said grain boundaries of the crystal grains are insulated by at least one insulating agent selected from the group consisting of Mn, Bi, Cu, Pb, B and Si, and that the maximum crystal grain present in the semiconducting ceramic body has a grain size ranging from 100 to 250.mu.. The composition contains 0.02 to 0.2 mole % of Mn as a mineralizing agent or insulating agent. The composition may further contain at least one of 0.05 to 0.5 mole % of SiO.sub.2 and 0.02 to 0.2 mole % of Al.sub.2 O.sub.3.