Solid electrolytic capacitor containing a protective adhesive layer
An electrolytic capacitor containing a protective adhesive layer positioned between the dielectric layer and the solid electrolyte layer (e.g., a conductive polymer layer, manganese dioxide) is generally disclosed. The protective adhesive layer can include a polymer having a repeating unit with a functional hydroxyl group, such as poly(vinyl alcohol). For instance, the polymer can be at least 90 mole % hydrolyzed. The polyvinyl alcohol can be a co-polymer of vinyl alcohol and a monomer, such as an acrylic ester like a methacrylic ester (e.g., methyl methacrylate).
1. A solid electrolytic capacitor comprising:
an anode;
a dielectric layer overlying the anode;
a protective adhesive layer overlying the dielectric layer, wherein the protective adhesive layer comprises a polymer having a repeating unit with a functional hydroxyl group, wherein the polymer has a degree of hydrolysis of at least about 90 mole %; and
a solid electrolyte layer overlying the protective adhesive layer.
2. A solid electrolytic capacitor as in claim 1 , wherein the polymer comprises a hydrophilic polymer.
3. A solid electrolytic capacitor as in claim 1 , wherein the polymer has a degree of hydrolysis of at least about 95 mole %.
4. A solid electrolytic capacitor as in claim 1 , wherein the polymer is poly(vinyl alcohol) or a copolymer thereof.
5. A solid electrolytic capacitor as in claim 1 , wherein the protective adhesive layer further comprises an acrylate, methacrylate, or a combination thereof.
6. A solid electrolytic capacitor as in claim 1 , wherein the protective adhesive layer has a resistivity of greater than about 5 ohm-cm.
7. A solid electrolytic capacitor as in claim 1 , wherein the protective adhesive layer has a resistivity of greater than about 1000 ohm-cm.
8. A solid electrolytic capacitor as in claim 1 , wherein the protective adhesive layer has a thickness of about 50 micrometers or less.
9. A solid electrolytic capacitor as in claim 1 , wherein the solid electrolyte layer comprises a conductive polymer.
10. A solid electrolytic capacitor comprising:
an anode;
a dielectric layer overlying the anode;
a protective adhesive layer overlying the dielectric layer, wherein the protective adhesive layer comprises a polymer having a repeating unit with a functional hydroxyl group; and
a solid electrolyte layer overlying the protective adhesive layer, wherein the solid electrolyte layer comprises a conductive polymer, and wherein the conductive polymer is polymerized in the presence of less than a stoichiometric amount of the oxidative polymerization catalyst.
11. A solid electrolytic capacitor as in claim 1 , further comprising a barrier layer overlying the solid electrolyte layer.
12. A solid electrolytic capacitor as in claim 1 , wherein the anode contains a valve metal.
13. A solid electrolytic capacitor as in claim 12 , wherein the anode contains tantalum or a niobium oxide.
14. A solid electrolytic capacitor as in claim 10 , wherein the polymer has a degree of hydrolysis of at least about 90 mole %.
15. A solid electrolytic capacitor as in claim 10 , wherein the polymer has a degree of hydrolysis of at least about 95 mole %.
16. A solid electrolytic capacitor as in claim 10 , wherein the polymer is poly(vinyl alcohol) or a copolymer thereof.
17. A solid electrolytic capacitor as in claim 10 , wherein the protective adhesive layer further comprises an acrylate, methacrylate, or a combination thereof.
18. A solid electrolytic capacitor as in claim 10 , wherein the protective adhesive layer has a resistivity of greater than about 5 ohm-cm.
19. A solid electrolytic capacitor as in claim 10 , wherein the protective adhesive layer has a resistivity of greater than about 1000 ohm-cm.
20. A solid electrolytic capacitor as in claim 10 , wherein the protective adhesive layer has a thickness of about 50 micrometers or less.
21. A solid electrolytic capacitor as in claim 10 , further comprising a barrier layer overlying the solid electrolyte layer.
22. A solid electrolytic capacitor as in claim 10 , wherein the anode contains a valve metal.
23. A solid electrolytic capacitor as in claim 22 , wherein the anode contains tantalum or a niobium oxide.
24. A solid electrolytic capacitor comprising:
an anode containing a valve metal;
a dielectric layer overlying the anode;
a protective adhesive layer overlying the dielectric layer, wherein the protective adhesive layer comprises a vinyl alcohol copolymer, wherein the vinyl alcohol copolymer is at least 90 mole % hydrolyzed; and
a solid electrolyte layer overlying the protective adhesive layer.
25. A solid electrolytic capacitor as in claim 24 , wherein the vinyl alcohol co-polymer is formed from a monomer that includes an acrylic ester, methacrylic ester, or a combination thereof.
26. A solid electrolytic capacitor as in claim 24 , wherein the protective adhesive layer has a resistivity of greater than about 5 ohm-cm.
27. A solid electrolytic capacitor as in claim 24 , wherein the protective adhesive layer has a thickness of about 50 micrometers or less.
28. A solid electrolytic capacitor as in claim 24 , wherein the solid electrolyte layer comprises a conductive polymer.
29. A solid electrolytic capacitor as in claim 24 , wherein the anode contains tantalum or a niobium oxide.
30. A solid electrolytic capacitor comprising:
an anode;
a dielectric layer overlying the anode;
a protective adhesive layer overlying the dielectric layer, wherein the protective adhesive layer comprises a polymer having a repeating unit with a functional hydroxyl group, wherein the polymer is a vinyl alcohol co-polymer formed from a monomer that includes an acrylic ester, methacrylic ester, or a combination thereof; and
a solid electrolyte layer overlying the protective adhesive layer, wherein the solid electrolyte layer comprises a conductive polymer.
31. A solid electrolytic capacitor as in claim 30 , wherein the monomer comprises methyl methacrylate.
32. A solid electrolytic capacitor as in claim 30 , wherein the polymer has a degree of hydrolysis of at least about 90 mole %.
33. A solid electrolytic capacitor as in claim 30 , wherein the polymer has a degree of hydrolysis of at least about 95 mole %.
34. A solid electrolytic capacitor as in claim 30 , wherein the protective adhesive layer further comprises an acrylate, methacrylate, or a combination thereof.
35. A solid electrolytic capacitor as in claim 30 , wherein the protective adhesive layer has a resistivity of greater than about 5 ohm-cm.
36. A solid electrolytic capacitor as in claim 30 , wherein the protective adhesive layer has a resistivity of greater than about 1000 ohm-cm.
37. A solid electrolytic capacitor as in claim 30 , wherein the protective adhesive layer has a thickness of about 50 micrometers or less.
38. A solid electrolytic capacitor as in claim 30 , wherein the solid electrolyte layer comprises a conductive polymer.
39. A solid electrolytic capacitor as in claim 30 , wherein the conductive polymer is polymerized in the presence of less than a stoichiometric amount of the oxidative polymerization catalyst.
40. A solid electrolytic capacitor as in claim 30 , further comprising a barrier layer overlying the solid electrolyte layer.
41. A solid electrolytic capacitor as in claim 30 , wherein the anode contains a valve metal.
42. A solid electrolytic capacitor as in claim 41 , wherein the anode contains tantalum or a niobium oxide.