Solid electrolytic capacitor with enhanced humidity resistance and method for producing the same

Patent metadata

Field	Value
Publication number	US-10224150-B2
Application number	US-201615013171-A
Country	US
Kind code	B2
Filing date	Feb 2, 2016
Priority date	Feb 2, 2016
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

An improved capacitor is provided. The capacitor comprises an anode and a functional dielectric on said anode and a conductive layer on the functional dielectric. An anode wire extends from said anode wherein the anode wire has a thickened dielectric layer thereon.

First claim

The invention claimed is:

1. A capacitor comprising:
an anode;
a functional dielectric on said anode;
a conductive layer on said functional dielectric;
an anode wire extending from said anode wherein said anode wire has a thickened dielectric region thereon; and
wherein said thickened dielectric region has a thickness of at least 1.1-10.0 times the thickness of said functional dielectric.

2. The capacitor of claim 1 wherein said anode comprises a valve metal or a conductive oxide of a valve metal.

3. The capacitor of claim 2 wherein said anode comprises a valve metal selected from the group consisting of tantalum, aluminum, niobium, titanium, zirconium and hafnium.

4. The capacitor of claim 1 wherein said thickened dielectric region has a thickness of at least 2-8 times the thickness of said functional dielectric.

5. The capacitor of claim 1 wherein said functional dielectric is an oxide of said anode.

6. The capacitor of claim 1 wherein said conductive layer comprises a conductive polymer.

7. The capacitor of claim 6 wherein said conductive polymer is selected from the group consisting of polythiophene, polypyrrole and polyaniline.

8. The capacitor of claim 7 wherein said conductive polymer comprises polymerized 3,4-ethylenedioxythiophene.

9. The capacitor of claim 6 further comprising a blocking polymer on said thickened dielectric.

10. The capacitor of claim 9 wherein said blocking polymer has lower conductivity than said conductive polymer.

11. A method for forming a capacitor comprising:
pressing and sintering a metal to form an anode with an anode wire extending therefrom;
forming a functional dielectric on said anode;
forming a conductive layer on said functional dielectric;
forming a thickened dielectric region on said anode wire; and
cleaning said anode wire prior to said forming said thickened dielectric region.

12. The method for forming a capacitor of claim 11 further comprising applying a blocking polymer on said thickened dielectric.

13. The method for forming a capacitor of claim 12 wherein said blocking polymer has a lower conductivity than said conductive layer.

14. The method for forming a capacitor of claim 11 wherein said anode comprises a valve metal or a conductive oxide of a valve metal.

15. The method for forming a capacitor of claim 14 wherein said anode comprises a valve metal selected from the group consisting of tantalum, aluminum, niobium, titanium, zirconium and hafnium.

16. The method for forming a capacitor of claim 11 wherein said thickened dielectric region has a thickness of at least 1.1-10.0 times the thickness of said functional dielectric.

17. The method for forming a capacitor of claim 16 wherein said thickened dielectric region has a thickness of at least 2-8 times the thickness of said functional dielectric.

18. The method for forming a capacitor of claim 11 wherein said functional dielectric is an oxide of said anode.

19. The method for forming a capacitor of claim 11 wherein said conductive layer comprises a conductive polymer.

20. The method for forming a capacitor of claim 19 wherein said conductive polymer is selected from the group consisting of polythiophene, polypyrrole and polyaniline.

21. The method for forming a capacitor of claim 20 wherein said conductive polymer comprises polymerized 3,4-ethylenedioxythiophene.

22. The method for forming a capacitor of claim 11 further comprising a blocking polymer on said thickened dielectric.

23. The method for forming a capacitor of claim 22 wherein said blocking polymer has lower conductivity than said conductive polymer.

24. A method for forming a capacitor comprising:
pressing and sintering a metal to form an anode with an anode wire extending therefrom;
forming a functional dielectric on said anode;
forming a conductive layer on said functional dielectric; and
forming a thickened dielectric region on said anode wire wherein said forming of said thickened dielectric region comprises applying a forming electrolyte to said anode wire in the presence of applied voltage.

25. A method for forming a capacitor comprising:
pressing and sintering a metal to form an anode with an anode wire extending therefrom;
forming a functional dielectric on said anode;
forming a conductive layer on said functional dielectric; and
forming a thickened dielectric region on said anode wire by applying an applied voltage wherein said applied voltage is higher than a formation voltage.

26. A method for forming a capacitor comprising:
pressing and sintering a metal to form an anode with an anode wire extending therefrom;
forming a functional dielectric on said anode;
forming a conductive layer on said functional dielectric; and
forming a thickened dielectric region on said anode wire by applying a forming electrolyte wherein said applying of said forming electrolyte comprises a conductive nozzle.

27. The method for forming a capacitor of claim 26 wherein said conductive nozzle comprises a metal syringe.

28. The method for forming a capacitor of claim 24 wherein said applying said forming electrolyte comprises pressure.

Assignees

• Kemet Electronics Corp

Inventors

• Ning Liancai
• Ya Qun

Classifications

• H01G9/028

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

• H01G9/0425 Primary

  specially adapted for cathode · CPC title

• H01G9/07

  Dielectric layers · CPC title

• H01G9/15

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

• H01G9/0036

  Formation of the solid electrolyte layer · CPC title