Process for producing electrolytic capacitors and capacitors made thereby

• US 8,771,381 B2
• Filed: 02/15/2012
• Issued: 07/08/2014
• Est. Priority Date: 02/15/2011
• Status: Active Grant

• Current Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Original Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Inventors: Chen, Qingping, Chacko, Antony P., Lessner, Philip M., Hahn, Randolph S., Qiu, Yongjian, Brenneman, Keith R., Zhang, Hong
• Primary Examiner(s): NIKMANESH, SEAHVOSH J
• Application Number:
  US13/396,793
• Publication Number:
  US 20120206860A1
• Time in Patent Office: 874 Days
• Field of Search: None
• US Class Current: 29/25.03
• CPC Class Codes: B05D 1/185 applying monomolecular layers B05D1/204 takes precedence
• CPC Class Codes: B82Y 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: H01G 9/0032 formation of the dielectric layer
• CPC Class Codes: H01G 9/0036 Formation of the solid electrolyte layer
• CPC Class Codes: H01G 9/028 Organic semiconducting electrolytes, e.g. TCNQ
• CPC Class Codes: H01G 9/0425 specially adapted for cathode
• CPC Class Codes: H01G 9/052 Sintered electrodes
• CPC Class Codes: H01G 9/15 Solid electrolytic capacitors H01G11/00 takes precedence
• CPC Class Codes: Y10S 977/948 Energy storage/generating using nanostructure, e.g. fuel cell, battery
• CPC Class Codes: Y10T 29/43 Electric condenser making

Abstract

A process for preparing a solid electrolytic capacitor comprising application of a non-ionic polyol prior to application of a conducting polymer layer.

Claims

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 layer of dielectric;

forming a layer of non-ionic polyol on said conductive polymer layer; and

forming a second conductive polymer layer on said layer of non-ionic polyol.

2. The method for forming an electrolytic capacitor of claim 1 comprising:

forming a subsequent layer of non-ionic polyol.

3. The method of forming an electrolytic capacitor of claim 2 comprising forming a subsequent layer of conductive polymer on said subsequent layer of non-ionic polyol.

4. 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.

5. 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 non-ionic polyol.

6. The method for forming an electrolytic capacitor of claim 1 wherein non-ionic polyol has a melting point of at least 50°

C. to no more than 250°

C.

7. The method for forming an electrolytic capacitor of claim 6 wherein non-ionic polyol has a melting point of at least 75°

C. to no more than 200°

C.

8. The method for forming an electrolytic capacitor of claim 1 wherein said non-ionic polyol comprises an alkyl of 3-20 carbons with at least two carbons each comprising at least one hydroxyl group.

9. The method for forming an electrolytic capacitor of claim 8 wherein at least one carbon is substituted with an alkyl group.

10. The method for forming an electrolytic capacitor of claim 9 wherein said alkyl group has 1 to 5 carbons.

11. The method for forming an electrolytic capacitor of claim 1 wherein said non-ionic polyol is selected from the group consisting of CH₂OH(CHOH)₂CH₂OH, CH₂OH(CHOH)₃CH₂OH, CH₂OHC(CH₂OH)₂CH₂OH, CH₂OHC(CH₃)₂CH₂OH, CH₂OH(CHOH)₄CH₂OH, CH₂OH(CHOH)₄CH₂OH, CH₃C(CH₂OH)₃, O(CH₂C(C₂H₅)CH₂OH)₂)₂, CH₂OH(CHOH)₄COH, CH₂OH(CHOH)₃COCH₂OH, sucrose and lactose.

12. The method for forming an electrolytic capacitor of claim 1 further comprising drying said conductive polymer layer.

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

14. The method for forming an electrolytic capacitor of claim 13 wherein said anode is selected from a group consisting of a valve metal and a conductive oxide of a valve metal.

15. The method for forming an electrolytic capacitor of claim 13 wherein said anode comprises a material selected from the group consisting of tantalum, aluminum, niobium and niobium oxide.

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

17. The method for forming an electrolytic capacitor of claim 16 wherein said conductive polymer is poly-3,4-ethylenedioxythiophene.

18. The method for forming an electrolytic capacitor of claim 1 further comprising forming a layer of nanoparticles on said conductive polymer layer.

19. The method for forming an electrolytic capacitor of claim 18 wherein said nanoparticles have an average particle size of no more than 100 nm.

20. The method for forming an electrolytic capacitor of claim 19 wherein said nanoparticles have an average particle size of no more than 50 nm.

21. The method for forming an electrolytic capacitor of claim 18 wherein said nanoparticles are selected from the group consisting of aluminum oxide, cerium oxide silicon oxide and zinc oxide.