Multiple leadwires using carrier wire for low ESR electrolytic capacitors

Patent metadata

Field	Value
Publication number	US-9905368-B2
Application number	US-201514817507-A
Country	US
Kind code	B2
Filing date	Aug 4, 2015
Priority date	Aug 4, 2015
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A solid electrolytic capacitor including a capacitor element, a first anode lead, a second anode lead, and a carrier wire. The capacitor element includes a sintered, porous anode body; a dielectric layer overlying the sintered, porous anode body; and a cathode overlying the dielectric layer that includes a solid electrolyte. The first and second anode leads each have an embedded portion positioned within the anode body and an external portion extending longitudinally from a surface of the anode body in an x-direction, while the carrier wire is positioned external to the anode body. Further, a first portion of the carrier wire is connected to the external portions of the first and second anode leads, while a second portion of the carrier wire extends longitudinally away from the surface of the anode body in the x-direction. Such an arrangement reduces the ESR and leakage current of the capacitor.

First claim

What is claimed is:

1. A solid electrolytic capacitor, the solid electrolytic capacitor comprising:
a capacitor element, wherein the capacitor element comprises a sintered, porous anode body; a dielectric layer overlying the sintered, porous anode body; and a cathode overlying the dielectric layer that includes a solid electrolyte;
a first anode lead having an embedded portion positioned within the sintered, porous anode body and an external portion extending longitudinally from a surface of the sintered, porous anode body in an x-direction;
a second anode lead having an embedded portion positioned within the sintered, porous anode body and an external portion extending longitudinally from a surface of the sintered, porous anode body in an x-direction;
a carrier wire positioned external to the sintered, porous anode body, wherein a first portion of the carrier wire is connected to the external portion of the first anode lead and the external portion of the second anode lead, further wherein a second portion of the carrier wire extends longitudinally away from the surface of the sintered, porous anode body in the x-direction such that the second portion of the carrier wire is parallel to the first anode lead and the second anode lead, wherein the second portion of the carrier wire has a diameter that is smaller than a diameter of the first anode lead and a diameter of the second anode lead, wherein a ratio of the diameter of either the first anode lead or the diameter of the second anode lead to the diameter of the carrier wire ranges from about 1.1 to about 5; and
an anode termination, wherein the second portion of the carrier wire is connected to the anode termination.

2. The solid electrolytic capacitor of claim 1 , wherein the carrier wire has a diameter ranging from about 50 micrometers to about 300 micrometers.

3. The solid electrolytic capacitor of claim 1 , wherein the first anode lead and the second anode lead each have a diameter ranging from about 200 micrometers to about 800 micrometers.

4. The solid electrolytic capacitor of claim 1 , wherein the first anode lead, the second anode lead, and the carrier wire comprise tantalum.

5. The solid electrolytic capacitor of claim 1 , wherein at least a part of the embedded portion of the first anode lead and a part of the embedded portion of the second anode lead are connected.

6. The solid electrolytic capacitor of claim 1 , wherein a part of the embedded portion of the first anode lead, a part of the embedded portion of the second anode lead, or both are flattened, crimped, or compressed.

7. The solid electrolytic capacitor of claim 1 , wherein the first portion of the carrier wire extends longitudinally away from the surface of the sintered, porous anode body in the x-direction, further wherein the first portion of the carrier wire is positioned between the external portion of the first anode lead and the external portion of the second anode lead.

8. The solid electrolytic capacitor of claim 1 , wherein the first portion of the carrier wire extends across the external portion of the first anode lead and the external portion of the second anode lead in a z-direction perpendicular to the x-direction in which the external portion of the first anode lead and the external portion of the second anode lead longitudinally extend.

9. The solid electrolytic capacitor of claim 1 , wherein the external portion of the first anode lead and the external portion of the second anode lead are connected to the first portion of the carrier wire by resistance welding, laser welding, or a combination thereof.

10. The solid electrolytic capacitor of claim 1 , wherein the second portion of the carrier wire is connected to an upstanding portion of the anode termination.

11. The solid electrolytic capacitor of claim 1 , further comprising a cathode termination that is electrically connected to the cathode.

12. The solid electrolytic capacitor of claim 1 , wherein the anode body is formed from a powder comprising tantalum, an electrically conductive oxide thereof, or an electrically conductive nitride thereof.

13. The solid electrolytic capacitor of claim 1 , wherein the solid electrolyte comprises a conductive polymer.

14. A method for forming a solid electrolytic capacitor, the method comprising:
positioning a first anode lead and a second anode lead within a powder formed from a valve metal composition, wherein the first anode lead includes an embedded portion located within a porous anode body and an external portion extending longitudinally from a surface of the porous anode body in an x-direction, and wherein the second anode lead includes an embedded portion located within the porous anode body and an external portion extending from a surface of the porous anode body in a longitudinal direction;
compacting the powder around the embedded portion of the first anode lead and the embedded portion of the second anode lead;
sintering the compacted powder to form a sintered, porous anode body;
positioning a carrier wire external to the sintered, porous anode body, wherein the carrier wire comprises a first portion and a second portion, wherein the second portion of the carrier wire has a diameter that is smaller than a diameter of the first anode lead and a diameter of the second anode lead, wherein a ratio of the diameter of either the first anode lead or the diameter of the second anode lead to the diameter of the carrier wire ranges from about 1.1 to about 5;
connecting the first portion of the carrier wire to the first anode lead and the second anode lead; and
connecting the second portion of the carrier wire to an anode termination to form an electrical connection between the second portion of the carrier wire and the anode termination, further wherein the second portion of the carrier wire extends longitudinally away from the surface of the sintered, porous anode body in the x-direction such that the second portion of the carrier wire is parallel to the first anode lead and the second anode lead.

15. The method of claim 14 , further comprising connecting at least a part of the embedded portion of the first anode lead to a part of the embedded portion of the second anode lead.

16. The method of claim 14 , further comprising flattening, crimping, or compressing a part of the embedded portion of the first anode lead, a part of the embedded portion of the second anode lead, or both.

17. The method of claim 14 , further comprising positioning the first portion of the carrier wire between the external portion of the first anode lead and the external portion of the second anode lead, wherein the first portion of the carrier wire extends longitudinally away from the surface of the sintered, porous anode body in the x-direction.

18. The method of claim 14 , further comprising positioning the first portion of the carrier wire across the external portion of the first anode lead and the external portion of the second anode lead in a z-direction perpendicular to the x-direction in which the external portion of the first anode lead and the external portion of the second anode lead longitudinally extend.

19. The method of claim 14 , further comprising:
anodically oxidizing the sintered, porous anode body to form a dielectric layer; and
applying a solid electrolyte to the anodically oxidized sintered, porous anode body to form a cathode;
forming an electrical connection between the cathode and a cathode termination; and
encapsulating the capacitor with a molding material such that at least a part of the anode termin

Assignees

• Avx Corp

Inventors

• Djebara Lotfi
• Kubes Ludek
• Matousek Radek
• Zednicek Stanislav

Classifications

• H01G9/028

  Organic semiconducting electrolytes, e.g. TCNQ · CPC title

• H01G9/012 Primary

  specially adapted for solid capacitors · CPC title

• H01G9/052 Primary

  Sintered electrodes · CPC title

• H01G9/15

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

• H01G9/025

  Solid electrolytes (H01G11/54 takes precedence) · CPC title