Multilayer ceramic capacitor

Patent metadata

Field	Value
Publication number	US-2024420896-A1
Application number	US-202418817544-A
Country	US
Kind code	A1
Filing date	Aug 28, 2024
Priority date	Jun 3, 2022
Publication date	Dec 19, 2024
Grant date	—

Abstract

A multilayer ceramic capacitor includes a multilayer body including an active layer portion including internal electrode layers and dielectric layers opposed to each other in a height direction. The active layer portion includes first and second lateral surface-side active layer portions, and a middle active layer portion. An average thickness in the height direction of the dielectric layers inside the first and second lateral surface-side active layer portions is smaller than an average thickness in the height direction of the dielectric layers inside the middle active layer portion. An average particle size of a ceramic material in the dielectric layers inside the first and second lateral surface-side active layer portions is larger than an average particle size of the ceramic material in the dielectric layers inside the middle active layer portion.

First claim

What is claimed is:

1 . A multilayer ceramic capacitor comprising:
a multilayer body including:
a plurality of dielectric layers and a plurality of internal electrode layers laminated therein;
a first main surface and a second main surface opposed to each other in a height direction;
a first lateral surface and a second lateral surface opposed to each other in a width direction orthogonal or substantially orthogonal to the height direction;
a first end surface and a second end surface opposed to each other in a length direction orthogonal or substantially orthogonal to the height direction and the width direction; and
an active layer portion including the plurality of internal electrode layers opposed to each other in the height direction with a corresponding one of the plurality of dielectric layers interposed therebetween; wherein
the plurality of dielectric layers each include a ceramic material; the active layer portion includes:
a first lateral surface-side edge adjacent to the first lateral surface and extending in the height direction;
a second lateral surface-side edge adjacent to the second lateral surface and extending in the height direction;
a first lateral surface-side active layer portion including a region from the first lateral surface-side edge toward an inside of the active layer portion in the width direction;
a second lateral surface-side active layer portion including a region from the second lateral surface-side edge toward the inside of the active layer portion in the width direction; and
a middle active layer portion including a region in a vicinity of a middle portion of the active layer portion in the width direction; and
an average thickness in the height direction of the plurality of dielectric layers inside the first lateral surface-side active layer portion and the second lateral surface-side active layer portion is smaller than an average thickness in the height direction of the plurality of dielectric layers inside the middle active layer portion; and an average particle size of the ceramic material in the plurality of dielectric layers inside the first lateral surface-side active layer portion and the second lateral surface-side active layer portion is larger than an average particle size of the ceramic material in the plurality of dielectric layers inside the middle active layer portion.

2 . The multilayer ceramic capacitor according to claim 1 , wherein a ratio of a minimum thickness in the height direction of the plurality of dielectric layers inside of each of the first lateral surface-side active layer portion and the second lateral surface-side active layer portion relative to a maximum particle size of the ceramic material in the plurality of dielectric layers inside of each of the first lateral surface-side active layer portion and the second lateral surface-side active layer portion is about 0.83 or more and about 1.82 or less.

3 . The multilayer ceramic capacitor according to claim 1 , wherein the ceramic material in each of the plurality of dielectric layers includes a perovskite structure including Ba, Sr, Zr, Ti, Hf, and Si,

4 . The multilayer ceramic capacitor according to claim 3 , wherein the ceramic material in each of the plurality of dielectric layers includes Ca.

5 . The multilayer ceramic capacitor according to claim 1 , wherein a number of moles of Sr/(number of moles of Ba+number of moles of Ca+number of moles of Sr) is from about 0.6 to about 0.95.

6 . The multilayer ceramic capacitor according to claim 1 , wherein the number of moles of Zr/(number of moles of Zr+number of moles of Ti+number of moles of Hf) is from about 0.9 to about 0.98.

7 . The multilayer ceramic capacitor according to claim 3 , wherein (number of moles of Ba+number of moles of Ca+number of moles of Sr)/(number of moles of Zr+number of moles of Ti+number of moles of Hf) is about 1.00 or more and about 1.03 or less.

8 . The multilayer ceramic capacitor according to claim 1 , wherein a thickness of each of the plurality of dielectric layers is about 0.7 μm or more and about 2.5 μm or less.

9 . The multilayer ceramic capacitor according to claim 1 , wherein a number of the plurality of dielectric layers is 10 or more and 1500 or less.

10 . The multilayer ceramic capacitor according to claim 1 , wherein each of the plurality of internal electrode layers includes Ni, Cu, Ag, Pd or Au, or an alloy including at least one of Ni, Cu, Ag, Pd or Au.

11 . The multilayer ceramic capacitor according to claim 1 , wherein a thickness of each of the plurality of internal electrode layers is about 0.2 μm or more and about 1.5 μm or less.

12 . The multilayer ceramic capacitor according to claim 1 , wherein a number of the plurality of internal electrode layers is 10 or more and 1500 or less.

13 . The multilayer ceramic capacitor according to claim 1 , wherein Sn is provided at an interface between the plurality of internal electrode layers and the plurality of dielectric layers.

14 . The multilayer ceramic capacitor according to claim 1 further comprising:
a first external electrode on the first end surface; and
a second external electrode on the second end surface.

15 . The multilayer ceramic capacitor according to claim 14 , wherein
the first external electrode extends from the first end surface to portions of the first and second main surfaces and portions of the first and second lateral surfaces; and the second external electrode extends from the second end surface to portions of the first and second main surfaces and portions of the first and second lateral surfaces.

16 . The multilayer ceramic capacitor according to claim 14 , wherein each of the first and second external electrodes includes a base electrode layer and a plated layer on the base electrode layer.

17 . The multilayer ceramic capacitor according to claim 16 , wherein the base electrode layer is a fired layer including a metal component and a glass component.

18 . The multilayer ceramic capacitor according to claim 17 , wherein the metal component includes at least one of Cu, Ni, Ag, Pd, Ag—Pd alloys, or Au.

19 . The multilayer ceramic capacitor according to claim 17 , wherein the glass component includes at least one of B, Si, Ba, Mg, Al, or Li.

20 . The multilayer ceramic capacitor according to claim 16 , wherein a thickness of the base electrode layer on each of the first end surface and the second end surface is about 3 μm or more and about 160 μm or less in a middle portion of the first base electrode layer in the height direction and the width direction.

Assignees

• Murata Manufacturing Co

Inventors

• Sugita Hiroaki

Classifications

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01G4/30 Primary

  Stacked capacitors (H01G4/33 takes precedence) · CPC title

• C04B35/46

  based on titanium oxides or titanates (containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49) · CPC title

• H01G4/012

  Form of non-self-supporting electrodes · CPC title

• H01G4/1209 Primary

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