Dielectric composition, dielectric element, electronic component and laminated electronic component

Patent metadata

Field	Value
Publication number	US-10438745-B2
Application number	US-201615745670-A
Country	US
Kind code	B2
Filing date	Jun 16, 2016
Priority date	Jul 17, 2015
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A dielectric composition, a dielectric element, an electronic component and a laminated electronic component are disclosed. In an embodiment the dielectric composition includes particles having a perovskite crystal structure including at least Bi, Na, Sr and Ti, wherein at least some of the particles have a core-shell structure including a core portion and a shell portion, and wherein the content of Bi present in the core portion is no greater than 0.83 times the content of Bi present in the shell portion.

First claim

The invention claimed is:

1. A dielectric composition comprising:
particles comprising a perovskite crystal structure including at least Bi, Na, Sr and Ti,
wherein at least some of the particles have a core-shell structure comprising a core portion and a shell portion, and
wherein a content of Bi present in the core portion is no greater than 0.83 times a content of Bi present in the shell portion.

2. The dielectric composition according to claim 1 , wherein S1:S2=1:99-30:70 in a cross section of the dielectric composition, where S1 is a mean cross-sectional area of the core portions, and wherein S2 is a mean cross-sectional area of the shell portions.

3. The dielectric composition according to claim 1 , wherein a total cross-sectional area of the core portions is 0.1%-15% with respect to the dielectric composition as a whole, in a cross section of the dielectric composition.

4. The dielectric composition according to claim 1 , wherein 0.125≤α≤2.00, where α is a molar ratio of Bi with respect to Sr in the dielectric composition.

5. The dielectric composition according to claim 1 , further comprising at least one element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Ba, Ca, Mg and Zn.

6. A dielectric element comprising the dielectric composition according to claim 1 .

7. An electronic component comprising:
a dielectric layer comprising the dielectric composition according to claim 1 .

8. A laminated electronic component comprising:
a laminated portion formed by alternately laminating an internal electrode layer and a dielectric layer comprising the dielectric composition according to claim 1 .

9. A single-layer ceramic capacitor comprising:
a disc-shaped dielectric body comprising the dielectric composition according to claim 1 ; and
a pair of electrodes wherein the electrodes are located on both surfaces of the dielectric body.

10. The single-layer ceramic capacitor according to claim 9 , wherein a material of the electrodes comprises Cu.

11. A laminated ceramic capacitor comprising:
a capacitor element main body having a structure in which dielectric layers comprising the dielectric composition according claim 1 and internal electrode layers are alternately stacked; and
a pair of conductive terminal electrodes connected, respectively, to the internal electrode layers alternately arranged inside the element main body, and the conductive terminal electrodes are located at both ends of the element main body.

12. The laminated ceramic capacitor according to claim 11 , wherein a material of the internal electrode layers comprises a base metal.

13. The laminated ceramic capacitor according to claim 11 , wherein a material of the internal electrode layers comprises Cu.

14. The laminated ceramic capacitor according to claim 11 , wherein a material of the internal electrode layers is Cu alloy.

15. The laminated ceramic capacitor according to claim 11 , wherein the conductive terminal electrodes comprise a conductive material having Cu as a main component.

16. A method for producing a laminated ceramic capacitor, the method comprising:
preparing a green chip using a sheet method or a printing method employing a paste for dielectric layers and a paste for internal electrodes, wherein the paste for the dielectric layers is an organic paint comprising a mixture of a dielectric starting material and an organic vehicle or wherein the paste for the dielectric layers is an aqueous paint comprising a mixture of a dielectric starting material and an aqueous vehicle;
performing a debinding treatment;
baking the green chip thereby forming a main body;
printing or transcribing external electrodes on the main body; and
baking the main body,
wherein the starting material is selected such that a dielectric composition comprises particles having a perovskite crystal structure including at least Bi, Na, Sr and Ti,
wherein at least some of the particles have a core-shell structure comprising a core portion and a shell portion, and
wherein a content of Bi present in the core portion is no greater than 0.83 times a content of Bi present in the shell portion.

17. The method according to claim 16 , wherein the paste for the internal electrodes is prepared by mixing a conductive material comprising Au, Pt, Ag, Ag—Pd alloy, Cu or Ni, or various types of oxide which form the conductive material after baking, or organometallic compounds, or resinates with the organic vehicle, and wherein a paste for the external electrodes is prepared in the same way as the paste for the internal electrodes.

Assignees

• Tdk Electronics Ag

Inventors

• Hirose Masakazu
• Imura Tomoya
• Terada Tomohiro
• Tauchi Goushi

Classifications

• C04B2235/3208

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

• C04B2235/3213

  Strontium oxides or oxide-forming salts thereof · CPC title

• C01G29/006

  Compounds containing bismuth, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title

• C04B35/638

  Removal thereof · CPC title