Multilayer ceramic capacitor

Patent metadata

Field	Value
Publication number	US-2025336604-A1
Application number	US-202519260776-A
Country	US
Kind code	A1
Filing date	Jul 7, 2025
Priority date	Jul 5, 2023
Publication date	Oct 30, 2025
Grant date	—

Abstract

In a multilayer ceramic capacitor, an outer electrode film includes a first glass including a barium-boron-silicon-based glass, a strontium-boron-silicon-based glass, or a barium-strontium-boron-silicon-based glass, and a second glass including a bismuth-based glass. The first and second glass define glass domains in the outer electrode film. A glass domain exposed on a surface of the outer electrode film is defined as a first glass domain, and a glass domain exposed on an interface of the outer electrode film with the ceramic body is defined as a second glass domain. A concentration ratio of bismuth to silicon is larger in the first glass domain than in the second glass domain.

First claim

What is claimed is:

1 . A multilayer ceramic capacitor comprising:
a ceramic body including a plurality of stacked dielectric layers, a plurality of stacked inner electrode layers, a first main surface and a second main surface facing each other in a height direction, a first side surface and a second side surface facing each other in a width direction perpendicular or substantially perpendicular to the height direction, and a first end surface and a second end surface facing each other in a length direction perpendicular or substantially perpendicular to the height direction and the width direction; and a terminal electrode on the ceramic body and connected to some of the plurality of inner electrode layers; wherein the terminal electrode includes an outer electrode film in contact with the ceramic body; the outer electrode film includes at least a first glass including at least one of a barium-boron-silicon-based glass, a strontium-boron-silicon-based glass, or a barium-strontium-boron-silicon-based glass, and a second glass including a bismuth-based glass; the first glass and the second glass define glass domains in the outer electrode film; and when, of the glass domains, a glass domain exposed on a surface of the outer electrode film but not exposed on an interface of the outer electrode film with the ceramic body is defined as a first glass domain, and a glass domain not exposed on the surface of the outer electrode film but exposed on the interface of the outer electrode film with the ceramic body is defined as a second glass domain, a concentration ratio of bismuth to silicon is higher in a portion of the first glass domain that is exposed on the surface of the outer electrode film than in a portion of the second glass domain that is exposed on the interface of the outer electrode film with the ceramic body.

2 . The multilayer ceramic capacitor according to claim 1 , wherein the concentration ratio of bismuth to silicon in the glass domains is higher in portions of the glass domains that are closer to the surface of the outer electrode film than in portions of the glass domains that are closer to the interface of the outer electrode film with the ceramic body.

3 . The multilayer ceramic capacitor according to claim 1 , wherein a total number of the plurality of dielectric layers is 15 or more and 2000 or less.

4 . The multilayer ceramic capacitor according to claim 1 , wherein each of the plurality of dielectric layers includes barium titanate, calcium titanate, strontium titanate, or calcium zirconate as a main component.

5 . The multilayer ceramic capacitor according to claim 4 , wherein each of the plurality of dielectric layers includes a manganese compound, an iron compound, a chromium compound, a cobalt compound, or a nickel compound as a secondary component.

6 . The multilayer ceramic capacitor according to claim 1 , wherein a thickness of each of the plurality of dielectric layers is about 0.3 μm or more and about 10 μm or less.

7 . The multilayer ceramic capacitor according to claim 1 , wherein
a dimension of the ceramic body in the length direction is about 0.2 mm or more and about 10 mm or less; a dimension of the ceramic body in the width direction is about 0.1 mm or more and about 5 mm or less; and a dimension of the ceramic body in the height direction is about 0.1 mm or more and about 5 mm or less.

8 . The multilayer ceramic capacitor according to claim 1 , wherein each of the plurality of inner electrode layers includes nickel, copper, silver, palladium, or gold, or an alloy including at least one of nickel, copper, silver, palladium, or gold.

9 . The multilayer ceramic capacitor according to claim 1 , wherein a thickness of each of the plurality of inner electrode layers is about 0.2 μm or more and about 2.0 μm or less.

10 . The multilayer ceramic capacitor according to claim 1 , wherein a total number of the plurality of inner electrode layers is 15 or more and 2000 or less.

11 . The multilayer ceramic capacitor according to claim 1 , wherein the terminal electrode includes a nickel plating film covering the outer electrode film, and a tin plating film covering the nickel plating film.

12 . The multilayer ceramic capacitor according to claim 1 , wherein the outer electrode film includes the barium-boron-silicon-based glass and the bismuth-based glass.

13 . The multilayer ceramic capacitor according to claim 1 , wherein the concentration ratio of bismuth to silicon is at least about 1.8 times higher in the portion of the first glass domain that is exposed on the surface of the outer electrode film than in the portion of the second glass domain that is exposed on the interface of the outer electrode film with the ceramic body.

14 . A paste for a terminal electrode of a multilayer ceramic capacitor, the paste comprising:
at least a first glass including at least one of a barium-boron-silicon-based glass, a strontium-boron-silicon-based glass, or a barium-strontium-boron-silicon-based glass, and a second glass including a bismuth-based glass.

15 . The paste according to claim 14 , wherein the first glass includes a barium-boron-silicon-based glass.

Assignees

• Murata Manufacturing Co

Inventors

• Bando Kenichi
• Kobayashi Toshihiko

Classifications

• H01G4/012

  Form of non-self-supporting electrodes · CPC title

• H01G4/12

  Ceramic dielectrics {(H01G4/085 takes precedence)} · CPC title

• H01G4/232

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

• H01G4/248

  the terminals embracing or surrounding the capacitive element, e.g. caps (H01G4/252 takes precedence) · CPC title

• H01G4/1209

  characterised by the ceramic dielectric material (H01G4/1272, H01G4/1281 take precedence) · CPC title