Materials and method for improving corner and edge coverage of solid electrolytic capacitors

Patent metadata

Field	Value
Publication number	US-9236191-B2
Application number	US-201414490981-A
Country	US
Kind code	B2
Filing date	Sep 19, 2014
Priority date	Feb 15, 2011
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

A process for preparing a solid electrolytic capacitor comprising application of coverage enhancing catalyst followed by application of a conducting polymer layer. Coverage enhancing catalyst is removed after coating and curing.

First claim

The invention claimed is:

1. A method of forming an electrolytic capacitor comprising:
providing an anode with an anode lead extending therefrom;
forming a dielectric on said anode;
forming a conductive polymer layer on said dielectric;
forming a layer of coverage enhancement catalyst on said conductive polymer layer;
adding a subsequent layer of conductive polymer on said coverage enhancement catalyst; and
finishing said capacitor.

2. The method for forming an electrolytic capacitor of claim 1 further comprising activating said coverage enhancement catalyst.

3. The method for forming an electrolytic capacitor of claim 2 wherein said activating is by heat.

4. The method for forming an electrolytic capacitor of claim 1 further comprising washing prior to said finishing.

5. The method for forming an electrolytic capacitor of claim 1 wherein said forming a conductive polymer layer on said layer of dielectric comprises in-situ polymerization.

6. The method for forming an electrolytic capacitor of claim 1 further comprising dipping in a slurry of conductive polymer prior to said forming a layer of coverage enhancement catalyst.

7. The method for forming an electrolytic capacitor of claim 1 wherein said coverage enhancement catalyst is defined by Formula 1:

wherein R 1 is a hydrogen, an aliphatic group, an aromatic group, an akylaryl group, or a heterocyclic group.

8. The method for forming an electrolytic capacitor of claim 7 wherein R 1 is selected from hydrogen, a straight chain or branched alkyl of 1-6 carbons and phenyl.

9. The method for forming an electrolytic capacitor of claim 7 wherein said coverage enhancement catalyst is selected from the group consisting of glycine, alanine and lysine.

10. The method for forming an electrolytic capacitor of claim 1 wherein said coverage enhancement catalyst is defined by Formula 2:
R 2 —SO 3 − R 3 NH 3 +   Formula 2

wherein R 2 is an aliphatic hydrocarbon with up to 18 carbons, unsubstituted phenyl or a phenyl substituted with halogen, —OH, —COOH, C 1 -C 12 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 alkyi-CONH, phenyi-CONH, NO 2 , or benzyl; naphthyl which is unsubstituted or substituted with halogen, C 1 -C 12 alkyl, C 1 -C 4 alkoxy, C 5 -C 6 cycloalkyl, C 7 -C 9 aralkyl, camphoryl,
—CF 3 , —CCl 3 , —F or —NH 2 ;
R 3 is aliphatic hydrocarbon with up to 18 carbons, unsubstituted phenyl or a phenyl substituted with halogen, C 1 -C 12 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 alkyl-CONH, phenyl-CONH, NO 2 , or benzyl; naphthyl which is unsubstituted or substituted with halogen, C 1 -C 12 alkyl, C1-C4 alkoxy, C 5 -C 6 cycloalkyl, C 7 -C 9 aralkyl, camphoryl, —CF 3 , —CCl 3 , —F or —NH 2 .

11. The method for forming an electrolytic capacitor of claim 10 wherein R 3 is selected from a phenyl ring optionally substituted with at least one of an alkyl, a hydroxyl or a carboxylic acid.

12. The method for forming an electrolytic capacitor of claim 10 wherein said coverage enhancement catalyst is selected from the group consisting of:

wherein R 4 is aliphatic hydrocarbon with up to 18 carbons, unsubstituted phenyl or a phenyl substituted with halogen, C 1 -C 12 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 alkyl-CONH, phenyl-CONH, NO 2 , or benzyl; naphthyl which is unsubstituted or substituted with halogen, C 1 -C 12 alkyl, C 1 -C 4 alkoxy, C 5 -C 6 cycloalkyl, C 7 -C 9 aralkyl, camphoryl, —CF 3 , —CCl 3 , —F or —NH 2 .

13. The method for forming an electrolytic capacitor of claim 1 wherein said coverage enhancement catalyst is defined by Formula 3:

wherein:
R 5 -R 8 independently represent aliphatic hydrocarbons with up to 30 carbons or an aromatic hydrocarbon with 6-20 carbons; and
A is a counterion selected from the group consisting of halide and sulfonic acid.

14. The method for forming an electrolytic capacitor of claim 13 wherein said aliphatic hydrocarbon can be unsubstituted or substituted with carboxyl or alcohol groups.

15. The method for forming an electrolytic capacitor of claim 13 wherein said aromatic hydrocarbon can be unsubstituted or substituted with carboxyl, alcohol or alkyl groups.

16. The method for forming an electrolytic capacitor of claim 13 wherein A is defined by R 2 SO 3 — wherein R 2 is an aliphatic hydrocarbon with up to 18 carbons, unsubstituted phenyl or a phenyl substituted with halogen, —OH, —COOH, C 1 -C 12 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 alkyl-CONH, phenyl-CONH, NO 2 , or benzyl; naphthyl which is unsubstituted or substituted with halogen, C 1 -C 12 alkyl, C 1 -C 4 alkoxy, C 5 -C 6 cycloalkyl, C 7 -C 9 aralkyl, camphoryl, —CF 3 , —CCl 3 , —F or —NH 2 .

17. The method for forming an electrolytic capacitor of claim 13 wherein said coverage enhancement catalyst is C 13 H 33 N(CH 3 ) 3 + Br − .

18. The method for forming an electrolytic capacitor of claim 1 wherein said coverage enhancement catalyst is a nanoparticle.

19. The method for forming an electrolytic capacitor of claim 18 wherein said nanoparticle is added as a dispersion.

20. The method for forming an electrolytic capacitor of claim 18 wherein said nanoparticle has an average particle size of the nanoparticle of no more than 100 nm.

21. The method for forming an electrolytic capacitor of claim 20 wherein said nanoparticle has an average particle size of the nanoparticle of no more than 50 nm.

22. The method for forming an electrolytic capacitor of claim 18 wherein said nanoparticle are selected from aluminum oxide, zinc oxide, silicon oxide and cerium oxide.

23. The method for forming an electrolytic capacitor of claim 1 wherein said anode comprises a valve metal.

24. The method for forming an electrolytic capacitor of claim 23 wherein said valve metal is selected from a group consisting of a valve metal and a conductive oxide of a valve metal.

25. The method for forming an electrolytic capacitor of claim 23 wherein said anode comprises a material selected from the group consisting of tantalum, aluminum, niobium and niobium oxide.

26. The method for forming an electrolytic capacitor of claim 1 wherein said conductive polymer is selected from the group consisting to polyaniline, polythiophene and polypyrole.

27. The method for forming an electrolytic capacitor of claim 26 wherein said conductive polymer is poly-3,4-ethylenedioxythiophene.

28. The method for forming an electrolytic capacitor of claim 1 further comprising forming a subsequent layer of coverage enhancement catalyst on said subsequent conductive polymer layer.

29. The method for forming an electrolytic capacitor of claim 1 comprising multiple cycles of said forming conductive polymer layer said forming coverage enhancement catalyst layer.

30. The method for forming an electrolytic capacitor of claim 1 comprising 2-10 of said cycles.

31. A method of forming an electrolytic capacitor comprising:
providing an anode with an anode lead extending therefrom;
forming a dielectric on said anode;

forming a conductive polym

Assignees

• Kemet Electronics Corp
• Kemet Electroncis Corp

Inventors

• Chacko Antony P
• Jin Yang
• Hahn Randolph S
• Qiu Yongjian
• Lessner Philip M
• Brenneman Keith R

Classifications

• H01G9/15

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

• Y10T29/43

  Electric condenser making · CPC title

• H01G9/052

  Sintered electrodes · CPC title

• B82Y99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• H01G9/0425

  specially adapted for cathode · CPC title