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, 2005
Filed:
Jan. 28, 2003
Hiroyasu Konaka, Kusatsu, JP;
Tomoyuki Nakamura, Shiga-ken, JP;
Toshihiro Okamatsu, Moriyama, JP;
Harunobu Sano, Kyoto, JP;
Hiroyasu Konaka, Kusatsu, JP;
Tomoyuki Nakamura, Shiga-ken, JP;
Toshihiro Okamatsu, Moriyama, JP;
Harunobu Sano, Kyoto, JP;
Abstract
A dielectric ceramic has a ceramic structure of crystal grains and grain boundaries between the crystal grains. The crystal grains are of a main component represented by the formula ABOand an additive containing a rare earth element wherein A is at least one of barium, calcium, and strontium, barium being an essential element, and B is at least one of titanium, zirconium, and hafnium, titanium being an essential element. The average rare earth element concentration in the interior of the crystal grains is about 50% or less the average rare earth element concentration at the grain boundaries. Furthermore, about 20% to 70% of the crystal grains have a rare earth element concentration in the center of the crystal grain of at least about 1/50 the maximum rare earth element concentration in a region extending inward from the surface by a distance corresponding to about 5% of the diameter of the crystal grain.