Solid electrolytic capacitor

Patent metadata

Field	Value
Publication number	US-11170941-B2
Application number	US-202016815297-A
Country	US
Kind code	B2
Filing date	Mar 11, 2020
Priority date	Mar 22, 2019
Publication date	Nov 9, 2021
Grant date	Nov 9, 2021

Abstract

A solid electrolytic capacitor that includes a capacitor element laminate, a first external electrode, and a second external electrode. The capacitor element laminate includes capacitor elements, cathode lead-out layers, and a sealing body. At least one of the capacitor elements includes an anode foil, dielectric layers, and cathode layers. The first external electrode is connected to the anode foil exposed at the first end surface of the capacitor element laminate. The second external electrode is connected to the cathode lead-out layers exposed at the second end surface of the capacitor element laminate. The sealing body includes a first resin molded body and a second resin molded body. The first resin molded body and the second resin molded body are made of the same insulating material.

First claim

The invention claimed is:

1. A solid electrolytic capacitor comprising:
a capacitor element laminate having a first end surface and a second end surface, the capacitor element laminate having:
at least one capacitor element that includes an anode foil made of a valve-action metal and exposed at the first end surface of the capacitor element laminate, a first dielectric layer on a first surface of the anode foil, a second dielectric layer on a second surface of the anode foil opposite the first surface, a first cathode layer including a first solid electrolyte layer on the first dielectric layer, and a second cathode layer including a second solid electrolyte layer on the second dielectric layer;
a first cathode lead-out layer connected to the first cathode layer and exposed at the second end surface of the capacitor element laminate;
a second cathode lead-out layer connected to the second cathode layer and exposed at the second end surface of the capacitor element laminate; and
a sealing body that consists of a first resin molded body that encloses the capacitor element and the first and second cathode lead-out layers to define at least a first main surface of the capacitor element laminate, and a second resin molded body that encloses the capacitor element and the first and second cathode lead-out layers to define at least a second main surface of the capacitor element laminate, wherein the first resin molded body and the second resin molded body are made of the same insulating material, and an interface is present between the first resin molded body and the second resin molded body;

a first external electrode connected to the anode foil that is exposed at the first end surface of the capacitor element laminate; and
a second external electrode connected to the first and second cathode lead-out layers that are exposed at the second end surface of the capacitor element laminate.

2. The solid electrolytic capacitor according to claim 1 , wherein the interface between the first resin molded body and the second resin molded body is flush with a surface of a stack of the capacitor element and the first and second cathode lead-out layers closest to the second main surface of the capacitor element laminate.

3. The solid electrolytic capacitor according to claim 1 ,
wherein the first resin molded body defines the first main surface, a first lateral surface, and a second lateral surface of the capacitor element laminate, and
the second resin molded body defines the second main surface of the capacitor element laminate.

4. The solid electrolytic capacitor according to claim 3 , wherein the interface between the first resin molded body and the second resin molded body is flush with a surface of a cathode lead-out layer of the first and second cathode lead-out layers closest to the second main surface of the capacitor element laminate.

5. The solid electrolytic capacitor according to claim 3 , further comprising:
an insulating layer between the capacitor element and the sealing body and closest to the second main surface of the capacitor element laminate, and
wherein the interface between the first resin molded body and the second resin molded body is flush with a surface of the insulating layer.

6. The solid electrolytic capacitor according to claim 1 , wherein the interface between the first resin molded body and the second resin molded body is parallel to the first main surface and the second main surface of the capacitor element laminate.

7. The solid electrolytic capacitor according to claim 1 , wherein an outer shape of the capacitor element laminate is a rectangular parallelepiped.

8. The solid electrolytic capacitor according to claim 1 , wherein the insulating material of the first resin molded body and the second resin molded body includes at least a resin.

9. The solid electrolytic capacitor according to claim 8 , wherein the insulating material of the first resin molded body and the second resin molded body further includes a filler.

10. The solid electrolytic capacitor according to claim 9 , wherein the filler from the first resin molded body and the second resin molded body does not cross over the interface between the first resin molded body and the second resin molded body.

11. A solid electrolytic capacitor according to claim 1 , comprising:
a capacitor element laminate having a first end surface and a second end surface, the capacitor element laminate having:
at least one capacitor element that includes an anode foil made of a valve-action metal and exposed at the first end surface of the capacitor element laminate, a first dielectric layer on a first surface of the anode foil, a second dielectric layer on a second surface of the anode foil opposite the first surface, a first cathode layer including a first solid electrolyte layer on the first dielectric layer, and a second cathode layer including a second solid electrolyte layer on the second dielectric layer;
a first cathode lead-out layer connected to the first cathode layer and exposed at the second end surface of the capacitor element laminate;
a second cathode lead-out layer connected to the second cathode layer and exposed at the second end surface of the capacitor element laminate; and
a sealing body that includes a first resin molded body that encloses the capacitor element and the first and second cathode lead-out layers to define at least a first main surface of the capacitor element laminate, and a second resin molded body that encloses the capacitor element and the first and second cathode lead-out layers to define at least a second main surface of the capacitor element laminate, wherein the first resin molded body and the second resin molded body are made of the same insulating material;

a first external electrode connected to the anode foil that is exposed at the first end surface of the capacitor element laminate; and
a second external electrode connected to the first and second cathode lead-out layers that are exposed at the second end surface of the capacitor element laminate,
wherein a metal foil exposed at the second end surface of the capacitor element laminate is in a space between the first cathode lead-out layer and the second cathode lead-out layer where the at least one capacitor element is not present, and
the metal foil is a portion separated from the anode foil by a slit, and is completely insulated from the anode foil.

12. The solid electrolytic capacitor according to claim 11 , further comprising:
an insulating portion filling the slit between the metal foil and the anode foil.

13. The solid electrolytic capacitor according to claim 12 , wherein the insulating portion extends to at least one of the first surface and the second surface of the anode foil.

14. The solid electrolytic capacitor according to claim 13 , further comprising:
an insulating layer between the at least one of the first surface and the second surface of the anode foil and the insulating portion extending to the at least one of the first surface and the second surface of the anode foil.

Assignees

• Murata Manufacturing Co

Inventors

• Furukawa Takeshi
• Shirakawa Sachiko

Classifications

• H01G9/055

  Etched foil electrodes · CPC title

• H01G9/10

  Sealing, e.g. of lead-in wires · CPC title

• H01G9/0036

  Formation of the solid electrolyte layer · CPC title

• H01G9/15 Primary

  Solid electrolytic capacitors (H01G11/00 takes precedence) · CPC title

• H01G9/012

  specially adapted for solid capacitors · CPC title