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. 27, 2004
Filed:
Oct. 29, 2001
Galeb H. Maher, Williamstown, MA (US);
Samir Maher, Williamstown, MA (US);
MRA Laboratories, Inc., Adams, MA (US);
Abstract
A dielectric ceramic powder and multilayer ceramic capacitors made from the powders are disclosed. A dielectric start powder mixture includes at least ninety weight percent essentially pure barium titanate powder having an average particle size of from 0.2 to 1.2 microns; from 0.2 to 2.5 weight percent of barium lithium borosilicate; from 0.1 to 0.3 weight percent of MnCO ; 0.4 to 1.50 weight percent Nb or a niobate compound, or a molar equivalent of Ta O or a tantalum compound as a grain growth inhibitor; and, 0.4 to 1.2 weight percent of gadolinium oxide (Gd O ). The start powder mixture is calcined and then sintered in an open zirconia setter at from 950° C. to 1,025° C. to produce a dielectric ceramic body that satisfies X7R capacitor performance characteristics; that includes no hazardous heavy metal oxides; and, that may include silver-palladium electrodes having 85 weight percent or more of silver.