Capacitor and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-10079100-B2
Application number	US-201514865419-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Sep 25, 2014
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

Provided is a capacitor, which includes a first electrode including aluminum, a second electrode facing the first electrode, and a first dielectric layer interposed between the first electrode and the second electrode, including aluminum oxide, and having multiple pores defined in a surface of the first dielectric layer in contact with the second electrode.

First claim

What is claimed is:

1. A capacitor, comprising: a first electrode including aluminum;
a second electrode facing the first electrode; and a first dielectric layer interposed between the first electrode and the second electrode, including an aluminum oxide, and having a plurality of pores defined in a surface of the first dielectric layer in contact with the second electrode, wherein the first dielectric layer includes: a dense layer contacting the first electrode on a side facing the second electrode and a porous layer disposed between the dense layer and the second electrode and including the plurality of pores, the porous layer having a density lower than that of the dense layer.

2. The capacitor according to claim 1 , wherein a ratio of a total thickness of the first dielectric layer to a thickness of the dense layer is in a range of about 1:0.05 to about 1:1.

3. The capacitor according to claim 1 , wherein a surface of the first electrode in which the first dielectric layer is formed has a concavo-convex structure.

4. The capacitor according to claim 1 , further comprising: a third electrode facing the first electrode to dispose the first electrode between the second electrode and the third electrode; and a second dielectric layer interposed between the first electrode and the third electrode, including aluminum oxide, and having multiple pores defined in a surface in contact with the third electrode.

5. The capacitor according to claim 4 , wherein both surfaces of the first electrode have concavo-convex structures.

6. The capacitor according to claim 4 , wherein the first to third electrodes and the first and second dielectric layer form one unit structure, and at least two unit structures are connected by an adhesive layer.

7. The capacitor according to claim 1 , further comprising: a second dielectric layer disposed on an opposite surface of the first electrode, including aluminum oxide, and having multiple pores defined in a surface thereof, wherein the first and second electrodes and the first and second dielectric layers form one unit structure, and at least two unit structures are disposed on both sides of an electrode layer.

8. The capacitor according to claim 1 , further comprising: a third electrode facing the second electrode to dispose the second electrode between the first electrode and the third electrode; and a second dielectric layer interposed between the second electrode and the third electrode, including aluminum oxide, and having a plurality of pores in a surface in contact with the third electrode.

9. A method of manufacturing a capacitor, comprising: forming a first oxidized film having a plurality of pores in its surface by performing a first anodizing process on an aluminum film; forming a first dielectric layer in which a part of each pore of the first oxidized film is filled with aluminum oxide by performing a second anodizing process on the aluminum film on which the first oxidized film is formed, wherein the first dielectric layer including a dense layer contacting the first electrode on a side facing the second electrode and a porous layer disposed between the dense layer and the second electrode and including the plurality of pores, the porous layer having a density lower than that of the dense layer; and forming a metal layer on the first dielectric layer.

10. The method according to claim 9 , wherein the first oxidized film includes a first porous layer having a plurality of pores and a first dense layer having a first thickness, the first dense layer connected with the first porous layer, and the first dielectric layer includes a second porous layer having pores smaller than those of the first porous layer and a second dense layer connected with the second porous layer and having a second thickness larger than the first thickness.

11. The method according to claim 10 , wherein a size of each of the pores of the first dielectric layer is in a range of about 20 to about 90% of the size of the pores of the first oxidized film.

12. The method according to claim 9 , wherein the forming of the first oxidized film includes anodizing the first oxidized film with at least one electrolyte solution selected from the group consisting of phosphoric acid, sulfuric acid and oxalic acid.

13. The method according to claim 9 , wherein the forming of the first dielectric layer includes anodizing the first dielectric layer with at least one electrolyte solution selected from citric acid and boric acid.

14. The method according to claim 9 , wherein the forming of the first oxidized film further includes forming a concavo-convex structure in a surface of the aluminum film.

15. The method according to claim 9 , further comprising: forming a second oxidized film having a plurality of pores in its surface by performing a first anodizing process on the metal layer; forming a second dielectric layer in which a part of each pore of the second oxidized film is filled with aluminum oxide by performing a second anodizing process on the metal layer on which the second oxidized film is formed; and forming an electrode on the second dielectric layer.

16. The method according to claim 9 , wherein the forming of the first oxidized film and the forming of the first dielectric layer are performed to form an oxidized film and a dielectric layer on both surfaces of the aluminum film by being dipped in an electrolyte solution.

17. A method of manufacturing a capacitor, comprising: forming a first electrode including aluminum; selectively applying a first electrolyte and voltage to a portion of the first electrode to form an oxide layer defining a plurality of pores and partitions thereon in alternating relation; selectively applying a second electrolyte and voltage to the portion of the first electrode to thicken the oxide layer thereof according to a predetermined electrical characteristic for the capacitor; applying a second electrode to be in contact with the partitions; and interposing a first dielectric layer between the first electrode and the second electrode, the first dielectric layer including a dense layer contacting the first electrode on a side facing the second electrode and a porous layer disposed between the dense layer and the second electrode and including the plurality of pores, the porous layer having a density lower than that of the dense layer.

18. The method according to claim 17 , further comprising adaptively adjusting the second voltage or a current or a temperature or an application time of the second electrolyte, or a combination thereof to establish a predetermined thickness of a bottom wall of the plurality of pores.

19. The capacitor according to claim 1 , wherein the dielectric layer and the first electrode are directly coupled together without adhesive.

20. The capacitor according to claim 1 , further comprising a base substrate including silicon coupled to the first electrode.

Assignees

• Research & Business Found Sungkyunkwan Univ

Inventors

• Suh Su-Jeong
• Shin Jin-Ha
• Lee Chang-Hyoung

Classifications

• H01G9/15

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

• H01G9/07

  Dielectric layers · CPC title

• H01G9/055

  Etched foil electrodes · CPC title

• H01G9/048

  characterised by their structure (H01G11/22 takes precedence) · CPC title

• H01G9/045 Primary

  based on aluminium · CPC title