Dielectric ceramic and laminated ceramic capacitor

Patent metadata

Field	Value
Publication number	US-8964356-B2
Application number	US-201213418898-A
Country	US
Kind code	B2
Filing date	Mar 13, 2012
Priority date	Sep 28, 2009
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

A dielectric ceramic which is suitable for use in a laminated ceramic capacitor under a high-temperature environment, such as encountered in, for example, automobile use has a composition represented by the composition formula: (1−x) (Ba 1-y Ca y ) m TiO 3 +xCaTiO 3 +aRe 2 O 3 +bMgO+cMnO+dV 2 O 3 +eSiO 2 in which Re is Gd, Dy, Y, Ho, and/or Er), 0.001≦x≦0.02, 0.08≦y≦0.20, 0.99≦m≦1.05, 0.01≦a≦0.04, 0.005≦b≦0.035, 0≦c≦0.01, 0≦d≦0.01, 0.01≦e≦0.04 when a, b, c, d, and e are each expressed in terms of parts by mol with respect to 1 mol of (1−x) (Ba,Ca)TiO 3 +xCaTiO 3 . This dielectric ceramic can constitute the dielectric ceramic layers of a laminated ceramic capacitor.

First claim

The invention claimed is:

1. A dielectric ceramic having a composition represented by the composition formula:
(1−x) (Ba 1-y Ca y )TiO 3 +xCaTiO 3 +eSiO 2 ,

wherein 0.001≦x≦0.02 0.08≦y≦0.20, and 0.01≦e≦0.04 where e is expressed in terms of parts by mol with respect to 1 mol of (1−x) (Ba 1-y Ca y )TiO 3 +xCaTiO 3 .

2. The dielectric ceramic according to claim 1 , wherein 0.003≦x≦0.018 0.08≦y≦0.18, and 0.02≦e≦0.03.

3. A dielectric ceramic having a composition represented by the composition formula:
(1−x) (Ba 1-y Ca y ) m TiO 3 +xCaTiO 3 +aRe 2 O 3 +bMgO+cMnO+dV 2 O 3 +eSiO 2

wherein Re is at least one member selected from the group consisting of Gd, Dy, Y, Ho, and Er, 0.001≦x≦0.02, 0.08≦y≦0.20, 0.99≦m≦1.05, 0.01≦a≦0.04, 0.005≦b≦0.035, 0≦c≦0.01, 0≦d≦0.01, and 0.01≦e≦0.04 in which a, b, c, d, and e are each expressed in terms of parts by mol with respect to 1 mol of (1−x) (Ba 1-y Ca y ) m TiO 3 +xCaTiO 3 .

4. The dielectric ceramic according to claim 3 , wherein 0.003≦x≦0.018 0.08≦y≦0.18, and 0.02≦e≦0.03.

5. The dielectric ceramic according to claim 4 , wherein a≦0.025, b≦0.030, 0≦c, and 0≦d.

6. The dielectric ceramic according to claim 5 , wherein Re is Y.

7. The dielectric ceramic according to claim 3 , wherein a≦0.025, b≦0.030, 0<c, and 0<d.

8. The dielectric ceramic according to claim 3 , wherein Re is Y.

9. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 8 .

10. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 7 .

11. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 6 .

12. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 5 .

13. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 4 .

14. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 3 .

15. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 2 .

16. A laminated ceramic capacitor comprising:
a capacitor main body comprising a plurality of stacked dielectric ceramic layers, and a plurality of internal electrodes disposed at different interfaces between the dielectric ceramic layers; and
a plurality of external electrodes dispose at different positions from each other on an outer surface of the capacitor main body and electrically connected to the internal electrodes, wherein
the dielectric ceramic layers comprise the dielectric ceramic according to claim 1 .

Assignees

• Suzuki Shoichiro
• Takeda Toshikazu
• Ikeda Jun
• Morita Megumi
• Murata Manufacturing Co

Inventors

• Suzuki Shoichiro
• Takeda Toshikazu
• Ikeda Jun
• Morita Megumi

Classifications

• C04B2235/3208

  Calcium oxide or oxide-forming salts thereof, e.g. lime · CPC title

• C04B2235/79

  Non-stoichiometric products, e.g. perovskites (ABO3) with an A/B-ratio other than 1 · CPC title

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title

• C04B2235/6584

  at an oxygen percentage below that of air · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title