Joseph K Nance

US Patent:

6185087, Feb 6, 2001

Filed:

Apr 8, 1999

Appl. No.:

9/288079

Inventors:

Hyun D. Park - Greer SC
Joseph D. Nance - Central SC
Mike S. H. Chu - Lewiston NY
Yuval Avniel - Longmont CO

Assignee:

Kemet Electronics Corp. - Greenville SC
Ferro Electronic Materials Inc. - Niagara Falls NY

International Classification:

H01G 406
H01G 412
C04B 3546

US Classification:

3613214

Abstract:

Multilayer ceramic chip capacitors which satisfy X7R requirements and which are compatible with reducing atmosphere sintering conditions so that non-noble metals such as nickel, copper, and alloys thereof may be used for internal and external electrodes are made in accordance with the invention. The capacitors exhibit desirable dielectric properties (high capacitance, low dissipation factor, high insulation resistance), excellent performance on highly accelerated life testing, and very good resistance to dielectric breakdown. The dielectric layers preferably contain BaTiO. sub. 3 as the major component and CaTiO. sub. 3, BaO, CaO, SrO, Si0. sub. 2, MnO. sub. 2, Y. sub. 2 O. sub. 3, and CoO as minor components in such proportions so that there are present 0. 1 to 4 mol % CaTiO. sub. 3, 0. 1 to 2 mol % BaO, 0 to 1 mol % CaO, 0 to 1 mol % SrO, 0.