Laminated ceramic capacitor and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-9312069-B2
Application number	US-201514614465-A
Country	US
Kind code	B2
Filing date	Feb 5, 2015
Priority date	Aug 9, 2012
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A laminated body that contains a perovskite-type compound containing Sr, Ba, Zr, and Ti and containing; Si; Mn; Al; and V. When the total content of Zr and Ti is 100 parts by mol, the total content m of Sr and Ba meets 100≦m≦105, the Si content a meets 0.1≦a≦4.0, the Mn content b meets 0.1≦b≦4.0, the Al content c meets 0.01≦c≦3.0, the V content d meets 0.01≦d≦0.3, the molar ratio w of Sr and Ba to Sr meets 0.60≦w≦0.95, the molar ratio z of the total of Zr and Ti to Zr meets 0.92≦z≦0.98, w and y meets and the crystal grains are 1.2 μm or less in average grain size.

First claim

The invention claimed is:

1. A laminated ceramic capacitor comprising:
a laminated body comprising a plurality of stacked dielectric ceramic layers and a plurality of internal electrodes at interfaces between adjacent dielectric ceramic layers of the plurality of stacked dielectric ceramic layers; and
an external electrode on an outer surface of the laminated body and electrically connected to the plurality of internal electrodes,
wherein the laminated body contains:
Si, Mn, Al, V, and a perovskite-type compound containing Sr, Ba, Zr, and Ti,
when a total content of Zr and Ti is 100 parts by mol:
(a) a total content m (parts by mol) of Sr and Ba meets 100≦m≦105,
(b) a Si content a (parts by mol) meets 0.1≦a≦4.0,
(c) a Mn content b (parts by mol) meets 0.1≦b≦4.0,
(d) an Al content c (parts by mol) meets 0.01≦c≦3.0,
(e) a V content d (parts by mol) meets 0.01≦d≦0.3,
(f) a molar ratio w of a total of Sr and Ba to Sr meets 0.60≦w≦0.95,
(g) a molar ratio z (Zr/(Zr+Ti)) of a total of Zr and Ti to Zr meets 0.92≦z≦0.98, and
the plurality of dielectric ceramic layers each have crystal grains, and the crystal grains are 1.2 μm or less in average grain size.

2. The laminated ceramic capacitor according to claim 1 , wherein the perovskite-type compound also contains Ca, and when the total content of Zr and Ti is 100 parts by mol:
the total content of m includes Sr, Ba, and Ca,
the molar ratio w is the total of Sr, Ba, and Ca to Sr,
a molar ratio y is a total of Sr, Ba, and Ca to Ca meets 0≦y≦0.35, and
a total of a value of the w and a value of the y meets 0.6≦w+y≦0.95.

3. The laminated ceramic capacitor according to claim 1 , wherein the crystal grains are 1.0 μm or less in average grain size.

4. The laminated ceramic capacitor according to claim 1 , wherein the internal electrodes contain Ni or a Ni alloy.

5. A laminated ceramic capacitor comprising:
a laminated body comprising a plurality of stacked dielectric ceramic layers and a plurality of internal electrodes at interfaces between adjacent dielectric ceramic layers of the plurality of stacked dielectric ceramic layers; and
an external electrode on an outer surface of the laminated body and electrically connected to the internal electrodes,
wherein the laminated body contains:
Si, Mn, Al, V, and a perovskite-type compound containing Sr, Ba, Zr, and Ti,
when a total content of Zr and Ti is 100 parts by mol after the laminated body is subjected to dissolution treatment and made into a solution:
(a) a total content m (parts by mol) of Sr and Ba meets 100≦m≦105,
(b) a Si content a (parts by mol) meets 0.1≦a≦4.0,
(c) a Mn content b (parts by mol) meets 0.1≦b≦4.0,
(d) an Al content c (parts by mol) meets 0.01≦c≦3.0,
(e) a V content d (parts by mol) meets 0.01≦d≦0.3,
(f) a molar ratio w of a total of Sr and Ba to Sr meets 0.60≦w≦0.95,
(g) a molar ratio z of a total of Zr and Ti to Zr meets 0.92≦z≦0.98, and
the plurality of dielectric ceramic layers each have crystal grains, and the crystal grains are 1.2 μm or less in average grain size.

6. The laminated ceramic capacitor according to claim 5 , wherein the perovskite-type compound further contains Ca, and when the total content of Zr and Ti is 100 parts by mol after the laminated body is subjected to dissolution treatment and made into the solution:
the total content of m includes Sr, Ba, and Ca,
the molar ratio w is the total of Sr, Ba, and Ca to Sr,
a molar ratio y of a total of Sr, Ba, and Ca to Ca meets 0≦y≦0.35, and
a total of a value of the w and a value of the y meets 0.6≦w+y≦0.95.

7. The laminated ceramic capacitor according to claim 5 , wherein the crystal grains are 1.0 μm or less in average grain size.

8. The laminated ceramic capacitor according to claim 5 , wherein the internal electrodes contain Ni or a Ni alloy.

9. A laminated ceramic capacitor comprising:
a laminated body comprising a plurality of stacked dielectric ceramic layers and a plurality of internal electrodes at interfaces between adjacent dielectric ceramic layers of the plurality of stacked dielectric ceramic layers; and
an external electrode on an outer surface of the laminated body and electrically connected to the internal electrodes,
wherein the dielectric ceramic layers contain:
Si, Mn, Al, V, and a perovskite-type compound containing Sr, Ba, Zr, and Ti,
when a total content of Zr and Ti is 100 parts by mol:
(a) a total content m (parts by mol) of Sr and Ba meets 100≦m≦105,
(b) a Si content a (parts by mol) meets 0.1≦a≦4.0,
(c) a Mn content b (parts by mol) meets 0.1≦b≦4.0,
(d) an Al content c (parts by mol) meets 0.01≦c≦3.0,
(e) a V content d (parts by mol) meets 0.01≦d≦0.3,
(f) a molar ratio w of a total of Sr and Ba to Sr meets 0.60≦w≦0.95,
(g) a molar ratio z of a total of Zr and Ti to Zr meets 0.92≦z≦0.98, and
the plurality of dielectric ceramic layers each have crystal grains, and the crystal grains are 1.2 μm or less in average grain size.

10. The laminated ceramic capacitor according to claim 9 , wherein the perovskite-type compound further contains Ca, and when the total content of Zr and Ti is 100 parts by mol:
the total content of m includes Sr, Ba, and Ca,
the molar ratio w is the total of Sr, Ba, and Ca to Sr,
a molar ratio y of a total of Sr, Ba, and Ca to Ca meets 0≦y≦0.35, and
a total of a value of the w and a value of the y meets 0.6≦w+y≦0.95.

11. The laminated ceramic capacitor according to claim 9 , wherein the crystal grains are 1.0 μm or less in average grain size.

12. The laminated ceramic capacitor according to claim 9 , wherein the internal electrodes contain Ni or a Ni alloy.

13. A method for manufacturing a laminated ceramic capacitor, the method comprising:
(1) preparing a ceramic slurry by mixing a Si compound, a Mn compound, an Al compound, a V compound, and a powder including a perovskite-type compound containing Sr, Ba, Zr, and Ti,
wherein in the ceramic slurry, when a total content of Zr and Ti is 100 parts by mol:
a) a total content m (parts by mol) of Sr and Ba meets 100≦m≦105,
b) a Si content a (parts by mol) meets 0.1≦a≦4.0,
c) a Mn content b (parts by mol) meets 0.1≦b≦4.0,
d) an Al content c (parts by mol) meets 0.01≦c≦3.0,
e) a V content d (parts by mol) meets 0.01≦d≦0.3,
f) a molar ratio w of a total of Sr and Ba to Sr meets 0.60≦w≦0.95, and
g) a molar ratio z (Zr/(Zr+Ti)) of the total of Zr and Ti to Zr meets 0.92≦z≦0.98;
(2) forming the ceramic slurry into a sheet shape to obtain ceramic green sheets;
(3) stacking the ceramic green sheets and conductor patterns to form an unfired laminated body; and
(4) firing the unfired laminated body to obtain a laminated body that has a structure with internal electrodes provided at interfaces between adjacent dielectric ceramic layers of a plurality of stacked dielectric ceramic layers, and has crystal grains of 1.2 μm or less in average grain size included in the dielectric ceramic layers.

14. The method for manufacturing a laminated ceramic capacitor according to claim 13 , wherein the perovskite-type compound further contains Ca, and when the total content of Zr and Ti is 100 parts by mol:
the total content m includes Sr, Ba, and Ca,
the molar ratio w is the total of Sr, Ba, and Ca to Sr,
a molar ratio y of a total of Sr, Ba, and Ca to Ca meets 0≦y≦0.35, and
a total of a value of the w and a value of the y meets 0.6≦w+y≦0.95.

15. The method for manufacturing a laminated ceramic capacitor according to claim 13 , wherein the powder is a powder prepared by calcining and loosening a material containing a Sr compound, a Ba compound, a Ti compound, and a Zr compound

Assignees

• Murata Manufacturing Co

Inventors

• Nishimura Hitoshi
• Naito Masahiro
• Hirata Tomotaka
• Isota Shinya

Classifications

• H01G4/1227 Primary

  based on alkaline earth titanates · CPC title

• C04B35/62675

  characterised by the treatment temperature · CPC title

• C04B2235/3213

  Strontium oxides or oxide-forming salts thereof · CPC title

• C04B2235/785

  Submicron sized grains, i.e. from 0,1 to 1 micron · CPC title

• B32B18/00

  Layered products essentially comprising ceramics, e.g. refractory products · CPC title