Process for improving leakage and dissipation factor of solid electrolytic capacitors employing conductive polymer cathodes
AssigneeKemet Electronics Corporation
InventorsRandolph S. Hahn, Philip M. Lessner, Veeriya Rajasekaran
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Abstract
The adhesion of a conductive polymer film to an oxidized porous pellet anode is improved by the incorporation of a silane coupling agent in the polymer impregnating solution. The incorporation of the silane coupling agent also decreases leakage current and dissipation factor. Suitable silanes are those of the general formula (R1—R3)—Si—(OR2)3. Each of R2 and R3 is a C1-C6 alkyl group such as methyl, ethyl, or propyl R1 can be chosen from a wide variety of organic functional groups such as epoxy, glycidoxy, amino, and pyrrole. The most preferred silane is 3-glycidoxypropyltrimethoxysilane.
Claims16
A process for preparing a solid electrolytic capacitor having a conductive polymer counter electrode, the process comprising:
- (a) providing an oxidized porous capacitor pellet;
- (b) dipping the pellet in a solution comprising a solvent, a monomer, an oxidizing agent, a dopant, and a silane coupling agent;
- and
- (c) applying heat to the pellet so as to evaporate the solvent, thereby forming a conductive polymer film having the silane coupling agent incorporated therein.
A process for preparing a solid electrolytic capacitor having a conductive polymer counter electrode, the process comprising:
- (a) providing an oxidized porous capacitor pellet;
- (b) dipping the pellet in a solution comprising a solvent, a monomer, an oxidizing agent, a dopant, and a silane coupling agent;
- and
- (c) applying heat to the pellet so as to evaporate the solvent, thereby forming a conductive polymer film having the silane coupling agent incorporated therein;
- wherein the porous pellet is made from a material selected from the group consisting of tantalum, aluminum, niobium, titanium, zirconium, hafnium, and alloys thereof.
A process for preparing a solid electrolytic capacitor having a conductive polymer counter electrode, the process comprising:
- (a) providing an oxidized porous capacitor pellet;
- (b) dipping the pellet in a solution comprising a solvent, a monomer, an oxidizing agent, a dopant, and a silane coupling agent;
- and
- (c) applying heat to the pellet so as to evaporate the solvent, thereby forming a conductive polymer film having the silane coupling agent incorporated therein
- wherein the silane coupling agent is of the general formula (R1—R3)-Si-(OR2)3, wherein R1 is selected from the group consisting of epoxy, glycidoxy, amino, and pyrrole;
- and R2 and R3 are each C1-C6 alkyl.
Dependencies are inferred from the claim text.