Dielectric composition and multilayer ceramic capacitor

Patent metadata

Field	Value
Publication number	US-12183512-B2
Application number	US-202217964198-A
Country	US
Kind code	B2
Filing date	Oct 12, 2022
Priority date	May 12, 2020
Publication date	Dec 31, 2024
Grant date	Dec 31, 2024

Abstract

A dielectric composition that contains a first complex oxide represented by (Bi x Na 1-x )TiO 3 —CaTiO 3 and having a perovskite structure as a main component; and at least one second complex oxide having a perovskite structure selected from the group consisting of BaZrO 3 , SrZrO 3 , CaZrO 3 , NaNbO 3 , and NaTaO 3 as an auxiliary component. A tolerance factor t when the at least one second complex oxide is BaZrO 3 , NaNbO 3 , or NaTaO 3 is 0.9016≤t≤0.9035, a tolerance factor t when the at least one second complex oxide is SrZrO 3 is 0.9005≤t≤0.9025, and a tolerance factor t when the at least one second complex oxide is CaZrO 3 is 0.9000≤t≤0.9020.

First claim

The invention claimed is:

1. A dielectric composition comprising:
a first oxide represented by (Bi x Na 1-x ) TiO 3 —CaTiO 3 , wherein 0<x<1 and having a perovskite structure as a main component; and
at least one second oxide having a perovskite structure selected from the group consisting of BaZrO 3 , SrZrO 3 , CaZrO 3 , NaNbO 3 , and NaTaO 3 as an auxiliary component, wherein
when the at least one second oxide is BaZrO 3 , NaNbO 3 , or NaTaO 3 , a tolerance factor t is 0.9016≤t≤0.9035,
when the at least one second oxide is SrZrO 3 , the tolerance factor t is 0.9005≤t≤0.9025, and
when the at least one second oxide is CaZrO 3 , the tolerance factor t is 0.9000≤t≤0.9020.

2. The dielectric composition according to claim 1 , wherein the x is 0.5.

3. The dielectric composition according to claim 1 , further comprising at least one selected from the group consisting of Cu, Ni, Mn, Mg, and Al in an amount of more than 0 parts by mol and 5 parts by mol or less with respect to 100 parts by mol of Ti.

4. The dielectric composition according to claim 1 , wherein Ca is contained more inside a grain than at a grain boundary of the dielectric composition.

5. The dielectric composition according to claim 4 , wherein Zr is contained more inside the grain than at the grain boundary of the dielectric composition.

6. The dielectric composition according to claim 1 , wherein Zr is contained more inside a grain than at a grain boundary of the dielectric composition.

7. The dielectric composition according to claim 1 , wherein the first oxide is contained in an amount of 90 wt % or more in the dielectric composition.

8. The dielectric composition according to claim 1 , wherein the first oxide is contained in an amount of 95 wt % or more in the dielectric composition.

9. A multilayer ceramic capacitor comprising:
a plurality of dielectric layers and internal electrodes alternately laminated, wherein
each of the dielectric layers contains the dielectric composition according to claim 1 .

10. The multilayer ceramic capacitor according to claim 9 , wherein the x is 0.5.

11. The multilayer ceramic capacitor according to claim 9 , wherein the dielectric composition further comprised at least one selected from the group consisting of Cu, Ni, Mn, Mg, and Al in an amount of more than 0 parts by mol and 5 parts by mol or less with respect to 100 parts by mol of Ti.

12. The multilayer ceramic capacitor according to claim 9 , wherein Ca is contained more inside a grain than at a grain boundary of the dielectric composition.

13. The multilayer ceramic capacitor according to claim 12 , wherein Zr is contained more inside the grain than at the grain boundary of the dielectric composition.

14. The multilayer ceramic capacitor according to claim 9 , wherein Zr is contained more inside a grain than at a grain boundary of the dielectric composition.

15. The multilayer ceramic capacitor according to claim 9 , wherein the first oxide is contained in an amount of 90 wt % or more in the dielectric composition.

16. The multilayer ceramic capacitor according to claim 9 , wherein the first oxide is contained in an amount of 95 wt % or more in the dielectric composition.

Assignees

• Murata Manufacturing Co

Inventors

• Habu Daiki
• Nomura Keisuke

Classifications

• B32B18/00

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

• C04B2235/768

  Perovskite structure ABO3 · CPC title

• C04B2237/346

  Titania or titanates · CPC title

• C04B2237/68

  Forming laminates or joining articles wherein at least one substrate contains at least two different parts of macro-size, e.g. one ceramic substrate layer containing an embedded conductor or electrode · CPC title

• C04B2235/6025

  Tape casting, e.g. with a doctor blade · CPC title