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

• US 9,030,807 B2
• Filed: 02/15/2012
• Issued: 05/12/2015
• Est. Priority Date: 02/15/2011
• Status: Active Grant

• Current Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Original Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Inventors: Chacko, Antony P., Chen, Qingping, Lessner, Philip M., Hahn, Randolph S., Qiu, Yongjian, Brenneman, Keith R., Jin, Yang
• Primary Examiner(s): Sinclair, David M
• Application Number:
  US13/396,842
• Publication Number:
  US 20120206859A1
• Time in Patent Office: 1,182 Days
• Field of Search: 361/525
• US Class Current: 361/529
• 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 coverage enhancing catalyst followed by application of a conducting polymer layer wherein the conductive polymeric cathode comprises the coverage enhancement catalyst wherein the conductive polymeric layer has improved coverage of the corners and edges. Coverage enhancing catalyst is removed after coating and curing.

Claims

1. A capacitor comprising:

an anode,

a dielectric on said anode; and

a conductive polymeric cathode on said dielectric wherein said conductive polymeric cathode comprises a coverage enhancement catalyst wherein said coverage enhancement catalyst is defined by Formula 2;

R²—

SO₃⁻

R³NH₃⁺

wherein R² is an aliphatic hydrocarbon with up to 18 carbons, unsubstituted phenyl or a phenyl substituted with halogen, —

OH, —

COOH, C₁-C₁₂ alkyl, C₁-C₄ alkoxy, C₁-C₄ alkyl-CONH, phenyl-CONH, NO₂, or benzyl;

naphthyl which is unsubstituted or substituted with halogen, C₁-C₁₂ alkyl, C₁-C₄ alkoxy, C₅-C₆ cycloalkyl, C₇-C₉ aralkyl, camphoryl, —

CF₃, —

CCl₃, —

F or —

NH₂;

R³ is aliphatic hydrocarbon with up to 18 carbons, unsubstituted phenyl or a phenyl substituted with halogen, C₁-C₁₂ alkyl, C₁-C₄ alkoxy, C₁-C₄ alkyl-CONH, phenyl-CONH, NO₂, or benzyl;

naphthyl which is unsubstituted or substituted with halogen, C₁-C₁₂ alkyl, C₁-C₄ alkoxy, C₅-C₆ cycloalkyl, C₇-C₉ aralkyl, camphoryl, —

CF₃, —

CCl₃, —

F or —

NH₂.

2. The capacitor of claim 1 wherein R³ is selected from a phenyl ring optionally substituted with at least one of an alkyl, a hydroxyl or a carboxylic acid.

3. The capacitor of claim 1 wherein said coverage enhancement catalyst is selected from the group consisting of:

4. The capacitor of claim 1 wherein said anode comprises a valve metal.

5. The capacitor of claim 4 wherein said valve metal is selected from a group consisting of a valve metal and a conductive oxide of a valve metal.

6. The capacitor of claim 4 wherein said anode comprises a material selected from the group consisting of tantalum, aluminum, niobium and niobium oxide.

7. The capacitor of claim 1 wherein said conductive polymer is selected from the group consisting to polyaniline, polythiophene and polypyrole.

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