Multilayer ceramic capacitor

Patent metadata

Field	Value
Publication number	US-9659712-B2
Application number	US-201514822917-A
Country	US
Kind code	B2
Filing date	Aug 11, 2015
Priority date	Aug 13, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A multilayer ceramic capacitor includes a body and at least two outer electrodes. The body includes first and second main surfaces, an inner layer portion and first and second outer layer portions. In the inner layer portion, dielectric layers and conductive layers are alternately stacked on each other. The second outer layer portion includes an outer portion and an inner portion. A boundary region adjacent to the inner portion in the outer portion inclines toward the first main surface.

First claim

What is claimed is:

1. A multilayer ceramic capacitor comprising:
a body that includes a plurality of dielectric layers and a plurality of conductive layers stacked on each other in a stacking direction and that includes first and second main surfaces opposing each other in the stacking direction, first and second end surfaces opposing each other in a length direction and connecting the first and second main surfaces, and first and second side surfaces opposing each other in a width direction and connecting the first and second main surfaces and the first and second end surfaces; and
first and second outer electrodes that are disposed on portions of a surface of the body; wherein
the plurality of conductive layers include first conductive layers connected to the first outer electrode and second conductive layers connected to the second outer electrode;
the body includes a first outer layer portion including a first of the plurality of dielectric layers defining the first main surface, a second outer layer portion including a second of the plurality of dielectric layers defining the second main surface, and an inner layer portion adjacent to both of the first outer layer portion and the second outer layer portion, the inner layer portion includes a portion extending from a first outermost conductive layer positioned closest to the first main surface among the plurality of conductive layers through a second outermost conductive layer positioned closest to the second main surface among the plurality of conductive layers;
the second outer layer portion includes an outer portion including the second main surface and an inner portion disposed adjacent to both of the outer portion and the inner layer portion;
a composition ratio of Si relative to Ti of the outer portion is higher than that of the inner portion;
the outer portion includes a boundary region adjacent to the inner portion, the boundary region has a larger Si content compared to a central region of the outer portion in the stacking direction; and
as viewed from the width direction, the boundary region includes a portion which inclines toward the first main surface as the boundary region gets closer to one of the first and second end surfaces.

2. The multilayer ceramic capacitor according to claim 1 , wherein
as viewed from the length direction, the boundary region includes a portion which inclines toward the first main surface as the boundary region gets closer to one of the first and second side surfaces; and
a maximum distance in the stacking direction between the second main surface and the boundary region at a cross section of the body which is perpendicular to the length direction and including a center of the body is greater than a maximum distance in the stacking direction between the second main surface and the boundary region at a cross section of the body which is perpendicular to the width direction and including the center of the body.

3. The multilayer ceramic capacitor according to claim 2 , wherein
the first and second outer electrodes are disposed on portions of the second main surface of the body; and
a surface region adjacent to the inner portion in the outer portion has a higher content of Si than a central region of the outer portion in the stacking direction.

4. The multilayer ceramic capacitor according to claim 2 , wherein a composition ratio of a rare earth element relative to Ti of the dielectric layers included in the inner layer portion is higher than that of the outer portion.

5. The multilayer ceramic capacitor according to claim 1 , wherein a composition ratio of Mn relative to Ti of the dielectric layer included in the inner layer portion, a composition ratio of Mn relative to Ti of the dielectric layer included in the first outer layer portion, and a composition ratio of Mn relative to Ti of the dielectric layer included in the inner portion is higher than that of the outer portion.

6. The multilayer ceramic capacitor according to claim 1 , wherein
as viewed from the width direction, the first outermost conductive layer includes a portion which inclines toward the second main surface and the second outermost conductive layer includes a portion which inclines toward the first main surface; and
an amount by which the portion of the second outermost conductive layer inclines is greater than an amount by which the portion of the first outermost conductive layer inclines.

7. A multilayer ceramic capacitor comprising:
a body that includes a plurality of dielectric layers and a plurality of conductive layers stacked on each other in a stacking direction and that includes first and second main surfaces opposing each other in the stacking direction, first and second end surfaces opposing each other in a length direction and connecting the first and second main surfaces, and first and second side surfaces opposing each other in a width direction and connecting the first and second main surfaces and the first and second end surfaces; and
first and second outer electrodes that are disposed on portions of a surface of the body; wherein
the plurality of conductive layers include first conductive layers connected to the first outer electrode and second conductive layers connected to the second outer electrode;
the body includes a first outer layer portion including a first of the plurality of dielectric layers defining the first main surface, a second outer layer portion including a second of the plurality of dielectric layers defining the second main surface, and an inner layer portion adjacent to both of the first outer layer portion and the second outer layer portion, the inner layer portion includes a portion extending from a first outermost conductive layer positioned closest to the first main surface among the plurality of conductive layers through a second outermost conductive layer positioned closest to the second main surface among the plurality of conductive layers;
the second outer layer portion includes an outer portion including the second main surface and an inner portion disposed adjacent to both of the outer portion and the inner layer portion;
a composition ratio of Si to relative Ti of the outer portion is higher than that of the inner portion;
the outer portion includes a boundary region adjacent to the inner portion, the boundary portion has a larger Si content compared to a central region of the outer portion in the stacking direction; and
as viewed from the length direction, the boundary region includes a portion which inclines toward the first main surface as the boundary region gets closer to one of the first and second side surfaces.

8. The multilayer ceramic capacitor according to claim 7 , wherein a composition ratio of a rare earth element relative to Ti of the dielectric layers included in the inner layer portion is higher than that of the outer portion.

9. The multilayer ceramic capacitor according to claim 7 , wherein a composition ratio of Mn relative to Ti of the dielectric layer included in the inner layer portion, a composition ratio of Mn relative to Ti of the dielectric layer included in the first outer layer portion, and a composition ratio of Mn relative to Ti of the dielectric layer included in the inner portion is higher than that of the outer portion.

10. The multilayer ceramic capacitor according to claim 7 , wherein
as viewed from the width direction, the first outermost conductive layer includes a portion which inclines toward the second main surface and the second outermost conductive layer includes a portion which inclines toward the first main surface; and
an amount by which the portion of the second outermost conductive layer inclines is greater than an amount by which the portio

Assignees

• Murata Manufacturing Co

Inventors

• Sugita Hiroaki
• Kitano Shota

Classifications

• H01G4/232

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

• H01G4/1218

  based on titanium oxides or titanates (H01G4/1245 takes precedence) · CPC title

• H01G4/012

  Form of non-self-supporting electrodes · CPC title

• H01G4/30 Primary

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