Conductive polymer dispersion with enhanced coverage

• US 10,643,796 B2
• Filed: 12/15/2016
• Issued: 05/05/2020
• Est. Priority Date: 02/27/2012
• Status: Active Grant

• Current Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Original Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Inventors: Chacko, Antony P., Lessner, Philip M., Ols, John Joseph, Shi, Yaru, Chen, Qingping
• Primary Examiner(s): Talbot, Brian K
• Application Number:
  US15/379,729
• Publication Number:
  US 20170098512A1
• Time in Patent Office: 1,237 Days
• Field of Search: 427 79- 81
• CPC Class Codes: H01G 9/0036 Formation of the solid electrolyte layer
• CPC Class Codes: H01G 9/012 specially adapted for solid capacitors
• 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 9/045 based on aluminium
• CPC Class Codes: H01G 9/08 Housing; Encapsulation
• CPC Class Codes: H01G 9/15 Solid electrolytic capacitors H01G11/00 takes precedence
• CPC Class Codes: Y10T 29/43 Electric condenser making

Abstract

An improved process for forming an electrolytic capacitor is provided. The process comprises: providing an anode with an anode wire extending from the anode body; forming a dielectric on the anode to form an anodized anode; applying a first slurry wherein the first slurry comprises conducting polymer and polyanion, wherein the polyanion and conducting polymer are in a first weight ratio thereby forming a first slurry layer; and applying a second slurry on the first slurry layer wherein the second slurry comprises the conducting polymer and said polyanion and wherein the polyanion and the conducting polymer are in a second weight ratio wherein the second weight ratio is lower than the first weight ratio.

Claims

1. A process for forming an electrolytic capacitor comprising:

providing an anode body with an anode wire extending from said anode body;

forming a dielectric on said anode body to form an anodized anode;

applying a first slurry on said dielectric wherein said first slurry comprises conducting polymer and polyanion, wherein said polyanion and conducting polymer are in a first weight ratio thereby forming a first slurry layer; and

applying a second slurry on said first slurry layer wherein said second slurry comprises a crosslinker, said conducting polymer and said polyanion and wherein said polyanion and said conducting polymer are in a second weight ratio wherein said second weight ratio is lower than said first weight ratio wherein said first weight ratio is no more than 6 and said second weight ratio is no more than 3 wherein said slurry avoids instant agglomerate.

2. The method for forming an electrolytic capacitor of claim 1 wherein said first weight ratio is no more than 4.

3. The method for forming an electrolytic capacitor of claim 2 wherein said first weight ratio is no more than 3.4.

4. The method for forming an electrolytic capacitor of claim 3 wherein said first weight ratio is 3.0 to 3.4.

5. The method for forming an electrolytic capacitor of claim 1 wherein said second weight ratio is no more than 2.

6. The method for forming an electrolytic capacitor of claim 5 wherein said second weight ratio is no more than 1.

7. The method for forming an electrolytic capacitor of claim 1 wherein said second weight ratio is less than said first weight ratio by at least 5%.

8. The method for forming an electrolytic capacitor of claim 7 wherein said second weight ratio is less than said first weight ratio by at least 6%.

9. The method for forming an electrolytic capacitor of claim 8 wherein said second weight ratio is less than said first weight ratio by at least 8%.

10. The method for forming an electrolytic capacitor of claim 1 wherein said first slurry comprises a second crosslinker.

11. The method for forming an electrolytic capacitor of claim 1 wherein said polyanion and said crosslinker are in one molecule.

12. The method for forming an electrolytic capacitor of claim 1 wherein said crosslinker is an amine.

13. The method for forming an electrolytic capacitor of claim 12 wherein said amine is selected from a diamine and a monoamine.

14. The method for forming an electrolytic capacitor of claim 13 wherein said diamine is diaminodecane.

15. The method for forming an electrolytic capacitor of claim 13 wherein said monoamine is tris(hydroxymethyl)aminomethane.

16. The method for forming an electrolytic capacitor of claim 1 wherein said conductive polymer comprises thiophene.

17. The method for forming an electrolytic capacitor of claim 16 wherein said thiophene comprises polyethylenedioxythiophene.

18. The method for forming an electrolytic capacitor of claim 1 wherein said polyanion comprises sulfonic acid.

19. The method for forming an electrolytic capacitor of claim 18 wherein said sulfonic acid is toluene sulfonic acid or polystyrene sulfonic acid.

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

21. The method for forming an electrolytic capacitor of claim 20 wherein said valve metal comprises a material selected from the group consisting of Al, W, Ta, Nb, Ti, Zr or Hf.

22. A process for forming an electrolytic capacitor comprising:

providing an anode body with an anode wire extending from said anode body;

forming a dielectric on said anode body to form an anodized anode;

forming a layer of conductive polymer on said dielectric;

applying a first slurry on said layer of conductive polymer wherein said first slurry comprises conducting polymer and polyanion, wherein said polyanion and conducting polymer are in a first weight ratio thereby forming a first slurry layer; and

applying a second slurry on said first slurry layer wherein said second slurry comprises a crosslinker, said conducting polymer and said polyanion and wherein said polyanion and said conducting polymer are in a second weight ratio wherein said second weight ratio is lower than said first weight ratio wherein said first weight ratio is no more than 6 and said second weight ratio is no more than 3 wherein said slurry avoids instant agglomeration.

23. The method for forming an electrolytic capacitor of claim 22 wherein said first weight ratio is no more than 4.

24. The method for forming an electrolytic capacitor of claim 23 wherein said first weight ratio is no more than 3.4.

25. The method for forming an electrolytic capacitor of claim 24 wherein said first weight ratio is 3.0 to 3.4.

26. The method for forming an electrolytic capacitor of claim 22 wherein said second weight ratio is no more than 2.

27. The method for forming an electrolytic capacitor of claim 26 wherein said second weight ratio is no more than 1.

28. The method for forming an electrolytic capacitor of claim 22 wherein said second weight ratio is less than said first weight ratio by at least 5%.

29. The method for forming an electrolytic capacitor of claim 28 wherein said second weight ratio is less than said first weight ratio by at least 6%.

30. The method for forming an electrolytic capacitor of claim 29 wherein said second weight ratio is less than said first weight ratio by at least 8%.

31. The method for forming an electrolytic capacitor of claim 22 wherein said forming of said layer of conductive polymer on said dielectric comprises in-situ polymerization.

32. The method for forming an electrolytic capacitor of claim 22 wherein said first slurry comprises a second crosslinker.

33. The method for forming an electrolytic capacitor of claim 22 said polyanion and said crosslinker are in the same molecule.

34. The method for forming an electrolytic capacitor of claim 22 wherein said crosslinker is an amine.

35. The method for forming an electrolytic capacitor of claim 34 wherein said amine is selected from a diamine and a monoamine.

36. The method for forming an electrolytic capacitor of claim 35 wherein said diamine is diaminodecane.

37. The method for forming an electrolytic capacitor of claim 35 wherein said monoamine is tris(hydroxymethyl)aminomethane.

38. The method for forming an electrolytic capacitor of claim 22 wherein said conductive polymer comprises thiophene.

39. The method for forming an electrolytic capacitor of claim 38 wherein said thiophene comprises polyethylenedioxythiophene.

40. The method for forming an electrolytic capacitor of claim 22 wherein said polyanion comprises sulfonic acid.

41. The method for forming an electrolytic capacitor of claim 40 wherein said sulfonic acid is toluene sulfonic acid or polystyrene sulfonic acid.

42. The method for forming an electrolytic capacitor of claim 22 wherein said anode body comprises a valve metal.

43. The method for forming an electrolytic capacitor of claim 42 wherein said valve metal comprises a material selected from the group consisting of Al, W, Ta, Nb, Ti, Zr or Hf.