Multilayer ceramic capacitor including raised portions thicker from middle portion towards outer periphery

Patent metadata

Field	Value
Publication number	US-11967461-B2
Application number	US-202117479055-A
Country	US
Kind code	B2
Filing date	Sep 20, 2021
Priority date	Sep 24, 2020
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

A multilayer ceramic capacitor includes a multilayer body including dielectric layers and internal electrodes alternately laminated therein, and two end surfaces opposing each other in a length direction, and two side surfaces opposing each other in a width direction, and two external electrodes respectively on the two end surfaces of the multilayer body. At least one of two opposed main surfaces of the multilayer ceramic capacitor includes raised portions provided respectively on one side and another side with a middle portion of the main surface interposed therebetween. The raised portions are each raised to become thicker in the lamination direction from the middle portion toward an outer periphery of the main surface.

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 electrodes alternately laminated in a layered manner therein, and two end surfaces opposing each other in a length direction which intersects a lamination direction, and two side surfaces opposing each other in a width direction which intersects the lamination direction and the length direction; and
two external electrodes respectively on the two end surfaces of the multilayer body; wherein
at least one of two opposed main surfaces of the multilayer body in the lamination direction includes raised portions respectively on one side and another side with a middle portion of the main surface interposed therebetween;
each of the raised portions becomes thicker in the lamination direction from the middle portion toward an outer periphery of the main surface;
a distance in the lamination direction between a lowermost internal electrode and an uppermost internal electrode in each of the raised portions is greater than a distance in the lamination direction between the lowermost internal electrode and the uppermost internal electrode in the middle portion; and
in a cross-section in the length direction and the lamination direction, a thickness in the lamination direction of at least one of the raised portions is greater than a thickness in the lamination direction at at least one of the two end surfaces.

2. The multilayer ceramic capacitor according to claim 1 , wherein the raised portions are provided at locations in the main surface where both end portions in the width direction of the internal electrodes are provided along the lamination direction, and extend in the length direction of the main surface.

3. The multilayer ceramic capacitor according to claim 1 , wherein
the plurality of internal electrodes include opposing portions each of which faces opposing portions of adjacent internal electrodes in the lamination direction, and lead-out portions each of which extends from one side of the respective opposing portion in the length direction to one of the two external electrodes; and
the raised portions are at locations in the main surface where both end portions in the length direction of the opposing portions are provided along the lamination direction, and extend in the width direction of the main surface.

4. The multilayer ceramic capacitor according to claim 1 , wherein
the multilayer body includes outer layer portions on both sides in the lamination direction of an inner layer portion including the plurality of dielectric layers and the plurality of internal electrodes alternately laminated therein; and
when, in a first cross-section through the width direction and the lamination direction at a middle portion in the length direction of the multilayer body, a thickness in the lamination direction at a middle portion in the width direction of the multilayer body is defined as T 1 , and a thickness in the lamination direction at the raised portion is defined as T 2 , a relationship of T 1 and T 2 is T 1 <T 2 , and a difference of T 2 −T 1 is about 4% to about 40% with respect to a thickness of the outer layer portions.

5. The multilayer ceramic capacitor according to claim 4 , wherein a thickness of each of the outer layer portions is about 20 μm or less.

6. The multilayer ceramic capacitor according to claim 5 , wherein the thickness of each of the outer layer portions is about 10 μm or less.

7. The multilayer ceramic capacitor according to claim 4 , wherein each of the outer layer portions has a same or substantially a same thickness.

8. The multilayer ceramic capacitor according to claim 1 , wherein, when, in a first cross-section through the width direction and the lamination direction at a middle portion in the length direction of the multilayer body, a thickness in the lamination direction at the middle portion in the width direction of the multilayer body is defined as T 1 , and a thickness in the lamination direction at one or more of the raised portions is defined as T 2 , a relationship of T 1 and T 2 is T 1 <T 2 , and a difference of T 2 −T 1 is about 2 μm or more and about 50 μm or less.

9. The multilayer ceramic capacitor according to claim 1 , wherein, when, in a first cross-section through the width direction and the lamination direction at a middle portion in the length direction of the multilayer body, a thickness in the lamination direction at one or more of the raised portions of the multilayer body is defined as T 2 , and in a second cross-section through the lamination direction and the length direction at a middle portion in the width direction of the multilayer body, a thickness in the lamination direction at one or more of the raised portions is defined as T 4 , a relationship of T 4 and T 2 is T 4 <T 2 .

10. The multilayer ceramic capacitor according to claim 1 , wherein, when, in a second cross-section through the lamination direction and the length direction at a middle portion in the width direction of the multilayer body, a thickness in the lamination direction at a middle portion in the length direction of the multilayer body is defined as T 3 , a thickness in the lamination direction at one or more of the raised portions of the multilayer body is defined as T 4 , and a thickness in the lamination direction at both end portions of the multilayer body in the length direction is defined as T 5 , a relationship of T 3 , T 4 , and T 5 is T 5 <T 3 <T 4 .

11. The multilayer ceramic capacitor according to claim 1 , wherein the multilayer body has a dimension in the length direction L is about 0.2 mm or more and about 10 mm or less, a dimension in the width direction W is about 0.1 mm or more and about 10 mm or less, and a dimension in the lamination direction T is about 0.1 mm or more and about 5 mm or less.

12. The multilayer ceramic capacitor according to claim 1 , wherein each of the plurality of internal electrodes includes at least one of Ni, Cu, Ag, Pd, a Ag—Pd alloy, of Au.

13. The multilayer ceramic capacitor according to claim 1 , wherein the plurality of internal electrodes include 15 or more and 200 or less internal electrodes.

14. The multilayer ceramic capacitor according to claim 1 , wherein the plurality of dielectric layers include a dielectric ceramic including BaTiO 3 as a main component.

15. The multilayer ceramic capacitor according to claim 14 , wherein the plurality of dielectric layers further include at least one of a Mn compound, a Fe compound, a Cr compound, a Co compound, or a Ni compound as a sub-component.

16. The multilayer ceramic capacitor according to claim 1 , wherein each of the external electrodes extends to portions of the two side surfaces and the two main surfaces of the multilayer body.

Assignees

• Murata Manufacturing Co

Inventors

• Shimada Yasuyuki
• Tanaka Akira
• Kokawa Shinichi

Classifications

• H01G4/012 Primary

  Form of non-self-supporting electrodes · CPC title

• H01G4/232

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

• H01G4/30

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

• H01G4/1227

  based on alkaline earth titanates · CPC title

• H01G4/0085

  Fried electrodes · CPC title