Multilayer ceramic capacitor and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-10062509-B2
Application number	US-201615372905-A
Country	US
Kind code	B2
Filing date	Dec 8, 2016
Priority date	Dec 17, 2015
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A multilayer ceramic capacitor that includes a laminated body having a plurality of ceramic layers including crystal grains that have a perovskite structure, and a plurality of internal electrode layers; and external electrodes on first and second end surfaces of the laminated body and electrically connected to respective sets of the plurality of internal electrodes. In the ceramic layers, when the content of Ti is 100 parts by mol, the ceramic layers contain Ca at 0.10 to 15.00 parts by mol; Mg at 0.0010 to 0.0097 parts by mol; R at 0.50 to 4.00 parts by mol; M at 0.10 to 2.00 parts by mol; and Si at 0.50 to 2.00 parts by mol, and core parts of the crystal grains contain Ca.

First claim

What is claimed is:

1. A multilayer ceramic capacitor comprising:
a laminated body having a plurality of ceramic layers comprising crystal grains that have a perovskite structure and a plurality of internal electrode layers; and
a pair of external electrodes on a surface of the laminated body, each external electrode of the pair of external electrodes being electrically connected to a respective set of internal electrodes of the plurality of internal electrode layers,
the ceramic layers containing:
a perovskite compound comprising Ba, Ca, and Ti;
Mg;
R, wherein R represents at least one of rare-earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y;
M, wherein M represents at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W; and
Si, and

when a Ti content is 100 parts by mol, the ceramic layers containing:
Ca at 0.10 to 15.00 parts by mol;
Mg at 0.0010 to 0.0097 parts by mol;
R at 0.50 to 4.00 parts by mol;
M at 0.10 to 2.00 parts by mol; and
Si at 0.50 to 2.00 parts by mol, and
the crystal grains having core parts containing Ca.

2. The multilayer ceramic capacitor according to claim 1 , wherein the R is at least one of rare-earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb.

3. The multilayer ceramic capacitor according to claim 1 , wherein the R comprises R1 and R2, wherein
the R1 is at least one of rare-earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb,
the R2 is at least one of rare-earth elements Ce, Pr, Nd, Eu, Tm, Lu, and Tb, and
the R1/the R2 in parts by mol has a value of 4.0 or more.

4. The multilayer ceramic capacitor according to claim 1 , wherein:
Ca is 0.40 to 10.00 parts by mol,
Mg is 0.0010 to 0.0090 parts by mol,
R is 0.50 to 3.00 parts by mol,
M is 0.10 to 1.50 parts by mol, and
Si is 0.60 to 1.90 parts by mol.

5. The multilayer ceramic capacitor according to claim 1 , wherein:
Ca is 0.75 to 7.50 parts by mol,
Mg is 0.0010 to 0.0075 parts by mol,
R is 0.50 to 2.50 parts by mol,
M is 0.10 to 1.00 parts by mol, and
Si is 0.80 to 1.60 parts by mol.

6. A multilayer ceramic capacitor comprising:
a laminated body having a plurality of ceramic layers comprising crystal grains that have a perovskite structure and a plurality of internal electrode layers; and
a pair of external electrodes on a surface of the laminated body, each external electrode of the pair of external electrodes being electrically connected to a respective set of internal electrodes of the plurality of internal electrode layers,
the laminated body containing:
a perovskite compound comprising Ba, Ca, and Ti;
Mg;
R, wherein R is at least one of rare-earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y;
M, wherein M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W; and
Si,

when a Ti content is 100 parts by mol, the laminated body containing:
Ca at 0.10 to 15.00 parts by mol;
Mg at 0.0010 to 0.0097 parts by mol;
R at 0.50 to 4.00 parts by mol;
M at 0.10 to 2.00 parts by mol; and
Si at 0.50 to 2.00 parts by mol, and
the crystal grains having core parts containing Ca.

7. The multilayer ceramic capacitor according to claim 6 , wherein the R is at least one of rare-earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb.

8. The multilayer ceramic capacitor according to claim 6 , wherein the R comprises R1 and R2, wherein
the R1 is at least one of rare-earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb,
the R2 is at least one of rare-earth elements Ce, Pr, Nd, Eu, Tm, Lu, and Tb, and
the R1/the R2 in parts by mol has a value of 4.0 or more.

9. The multilayer ceramic capacitor according to claim 6 , wherein:
Ca is 0.40 to 10.00 parts by mol,
Mg is 0.0010 to 0.0090 parts by mol,
R is 0.50 to 3.00 parts by mol,
M is 0.10 to 1.50 parts by mol, and
Si is 0.60 to 1.90 parts by mol.

10. The multilayer ceramic capacitor according to claim 6 , wherein:
Ca is 0.75 to 7.50 parts by mol,
Mg is 0.0010 to 0.0075 parts by mol,
R is 0.50 to 2.50 parts by mol,
M is 0.10 to 1.00 parts by mol, and
Si is 0.80 to 1.60 parts by mol.

11. A multilayer ceramic capacitor comprising:
a laminated body having a plurality of ceramic layers comprising crystal grains that have a perovskite structure and a plurality of internal electrode layers; and
a pair of external electrodes on a surface of the laminated body, each external electrode of the pair of external electrodes being electrically connected to a respective set of internal electrodes of the plurality of the internal electrode layers,
the laminated body containing:
a perovskite compound comprising Ba, Ca, and Ti;
Mg;
R, wherein R represents at least one of rare-earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y;
M, wherein M represents at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W; and
Si, and

when a Ti content is 100 parts by mol when the laminated body is dissolved with a solvent, the laminated body containing:
Ca at 0.10 to 15.00 parts by mol;
Mg at 0.0010 to 0.0097 parts by mol;
R at 0.50 to 4.00 parts by mol;
M at 0.10 to 2.00 parts by mol; and
Si at 0.50 to 2.00 parts by mol, and
the crystal grains having core parts containing Ca.

12. A method for manufacturing a multilayer ceramic capacitor, the method comprising:
mixing a powder containing, as a main constituent, a perovskite compound comprising Ba, Ca, and Ti, a Mg compound, a compound of R, a compound of M, and an Si compound to obtain a ceramic slurry, wherein R is at least one of rare-earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W;
forming the ceramic slurry into ceramic green sheets;
forming a raw laminated body by laminating the ceramic green sheets and internal electrode patterns; and
firing the raw laminated body to obtain a laminated body with internal electrode layers, wherein
when a Ti content in the ceramic slurry is 100 parts by mol, the ceramic slurry contains:
Ca at 0.10 to 15.00 parts by mol;
Mg at 0.0010 to 0.0097 parts by mol;
R at 0.50 to 4.00 parts by mol;
M at 0.10 to 2.00 parts by mol; and
Si at 0.50 to 2.00 parts by mol.

13. The method for manufacturing a multilayer ceramic capacitor according to claim 12 , further comprising mixing a Ca compound with the powder containing the perovskite compound.

14. The method for manufacturing a multilayer ceramic capacitor according to claim 12 , wherein the R is at least one of rare-earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb.

15. The method for manufacturing a multilayer ceramic capacitor according to claim 12 , wherein the R comprises R1 and R2,
R1 is at least one of rare-earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb,
R2 is at least one of rare-earth elements Ce, Pr, Nd, Eu, Tm, Lu, and Tb, and
the R1/the R2 in parts by mol has a value of 4.0 or more.

16. The method for manufacturing a multilayer ceramic capacitor according to claim 12 , wherein:
Ca is 0.40 to 10.00 parts by mol,
Mg is 0.0010 to 0.0090 parts by mol,
R is 0.50 to 3.00 parts by mol,
M is 0.10 to 1.50 parts by mol, and
Si is 0.60 to 1.90 parts by mol.

17. The method for manufacturing a multilayer ceramic capacitor according to claim 12 , wherein:
Ca is 0.75 to 7.50 parts by mol,
Mg is 0.0010 to 0.0075 parts by mol,
R is 0.50 to 2.50 parts by mol,
M is 0.10 to 1.00 parts by mol, and
Si is 0.80 to 1.60 parts by mol.

Assignees

• Murata Manufacturing Co

Inventors

• Shimada Kohei

Classifications

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title

• C04B2235/3244

  Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof · CPC title

• C04B2235/3293

  Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO] · CPC title

• H01G4/232

  electrically connecting two or more layers of a stacked or rolled capacitor · CPC title

• C04B2235/6584

  at an oxygen percentage below that of air · CPC title