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:
Mar. 20, 2001
Filed:
Jan. 20, 1999
Nobuyuki Wada, Shiga-ken, JP;
Jun Ikeda, Omihachiman, JP;
Takashi Hiramatsu, Shiga-ken, JP;
Yukio Hamaji, Otsu, JP;
Abstract
A dielectric ceramic which exhibits an excellent electrostatic capacity-temperature characteristic; which allows use of a base metal such as nickel; which can be fired in a reducing atmosphere; and which is suitable for constituting a dielectric ceramic layer of a laminated ceramic electronic element such as a laminated ceramic capacitor; is obtained by firing barium titanate powder in which the c-axis/a-axis ratio in the perovskite structure is in the range of about 1.003 to 1.010 and the amount of OH groups in the crystal lattice is about 1 wt. % or less. The barium titanate powder a starting material preferably has a maximum particle size of about 0.5 &mgr;m or less and an average particle size of about 0.1-0.3 &mgr;m, and individual particles of the barium titanate powder comprise a low-crystallinity portion,and a high-crystallinity portion,, with the diameter of the low-crystallinity portion being less than about 0.65 times the particle size of the powder. When sintered, the powder satisfies the ratio of (average grain size of the fired dielectric ceramic)/(average particle size of barium titanate powder serving as a starting material), which is referred to as R, of about 0.90-1.2, to thereby suppress considerable grain growth. A laminated ceramic electronic element including a laminate of a plurality of layers of the above-mentioned dielectric ceramic, as well as a method for producing the same, is described.