Ceramic capacitor and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-2017169950-A1
Application number	US-201615368718-A
Country	US
Kind code	A1
Filing date	Dec 5, 2016
Priority date	Dec 10, 2015
Publication date	Jun 15, 2017
Grant date	—

Abstract

A ceramic capacitor includes first and second first internal electrodes respectively including first and second extended portions that respectively include a plurality of ceramic columns penetrating the first and the second extended portions, respectively, in a thickness direction. The first extended portion includes a first high ceramic-column density portion in which ceramic columns are provided at intervals of about 20 μm or less along the length direction of the extended portion. The second extended portion includes a second high ceramic-column density portion in which ceramic columns are provided at intervals of about 20 μm or less along the length direction of the extended portion.

First claim

What is claimed is:

1 . A ceramic capacitor comprising:
a capacitor main body including first and second main surfaces extending along a length direction and a width direction, first and second side surfaces extending along a length direction and a height direction, and first and second end surfaces extending along a width direction and a height direction and includes at least one dielectric layer; a first internal electrode provided within the capacitor main body and extended to the first end surface; a second internal electrode opposed to the first internal electrode within the capacitor main body and extended to the second end surface; a first external electrode disposed on the first end surface and connected to the first internal electrode; and a second external electrode disposed on the second end surface and connected to the second internal electrode; wherein the first internal electrode includes:
a first opposed portion which is opposed to the second internal electrode; and
a first extended portion which extends from the first opposed portion and to the first end surface;
the second internal electrode includes:
a second opposed portion which is opposed to the first opposed portion; and
a second extended portion which extends from the second opposed portion and to the second end surface;
the first and the second extended portions respectively including a plurality of ceramic columns penetrating the first and the second extended portions in a thickness direction; the first extended portion includes a first high ceramic-column density portion in which the ceramic columns are provided at intervals of about 20 μm or less along the length direction of the extended portion; and the second extended portion includes a second high ceramic-column density portion in which the ceramic columns are provided at intervals of about 20 μm or less along the length direction of the extended portion.

2 . The ceramic capacitor according to claim 1 , wherein
the first high ceramic-column density portion is provided at an end portion on a first end surface side of the first extended portion; and the second high ceramic-column density portion is provided at an end portion on a second end surface side of the second extended portion.

3 . The ceramic capacitor according to claim 1 , wherein a ratio of a sum of lengths in the length direction of a plurality of ceramic columns included in the first high ceramic-column density portion to a length in the length direction of the first high ceramic-column density portion is in a range of about 5% to about 50%.

4 . The ceramic capacitor according to claim 3 , wherein the ratio of the sum of lengths in the length direction of a plurality of ceramic columns included in the first high ceramic-column density portion to a length in the length direction of the first high ceramic-column density portion is in a range of about 10% to about 30%.

5 . The ceramic capacitor according to claim 1 , wherein a length along the length direction of each of the first and the second high ceramic-column density portions is about 20 μm or more.

6 . The ceramic capacitor according to claim 1 , wherein
in the length direction, a distance between the first opposed portion and the first high ceramic-column density portion is about 20 μm or more; and in the length direction, a distance between the second opposed portion and the second high ceramic-column density portion is about 20 μm or more.

7 . The ceramic capacitor according to claim 1 , wherein the high ceramic-column density portion in which the ceramic columns are provided at intervals of about 20 μm or less along the length direction, is not disposed in the first and the second opposed portions.

8 . The ceramic capacitor according to claim 1 , wherein a thickness dimension of the capacitor main body is in a range of about 0.1 mm to about 2.5 mm, a length dimension of the capacitor main body is in a range of about 0.2 mm to about 3.2 mm, and a width dimension of the capacitor main body is in a range of about 0.1 mm to about 2.5 mm.

9 . The ceramic capacitor according to claim 1 , wherein the at least one dielectric layer is made of a dielectric ceramic material.

10 . The ceramic capacitor according to claim 9 , wherein the dielectric ceramic material includes at least one of BaTiO 3 , CaTiO 3 , SrTiO 3 , and CaZrO 3 .

11 . The ceramic capacitor according to claim 10 , wherein the dielectric ceramic material further includes a sub component including at least a Mn compound, a Mg compound, a Si compound, a Fe compound, a Cr compound, a Co compound, a Ni compound and a rare-earth compound.

12 . The ceramic capacitor according to claim 1 , wherein the at least one dielectric layer includes a plurality of dielectric layers.

13 . The ceramic capacitor according to claim 1 , wherein a thickness of each of the at least one dielectric layer is in a range of about 0.5 μm to about 100 μm.

14 . A method for manufacturing the ceramic capacitor according to claim 1 , the method comprising:
a step of forming the first and second internal electrodes by firing a conductive paste layer; a step of forming the conductive paste layer including:
a step of forming a first portion for forming one of the first opposed portion and the second opposed portion by applying a first conductive paste; and
a step of forming a second portion for forming one of the first extended portion and the second extended portion by applying a second conductive paste different in a type from the first conductive paste.

15 . The method for manufacturing the ceramic capacitor according to claim 14 , wherein a conductive paste having a ceramic particle content rate that is higher than that in the first conductive paste is used as the second conductive paste.

16 . The method for manufacturing the ceramic capacitor according to claim 14 , wherein at least one of the first portion and the second portion is formed by printing by a noncontact printing method.

17 . The method for manufacturing the ceramic capacitor according to claim 16 , wherein the first portion and the second portion are formed by printing by a noncontact printing method.

18 . The method for manufacturing the ceramic capacitor according to claim 16 , wherein an inkjet printing method is used as the noncontact printing method.

Assignees

• Murata Manufacturing Co

Inventors

• Nakanishi Toru

Classifications

• H01G4/30 Primary

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

• H01G4/012

  Form of non-self-supporting electrodes · CPC title

• H01G4/232

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

• H01G4/1227

  based on alkaline earth titanates · CPC title

• H01G4/1236

  based on zirconium oxides or zirconates (H01G4/1263 takes precedence) · CPC title