Fabrication method of solid electrolytic capacitor

Abstract

A fabrication method of a solid electrolytic capacitor is provided, which decreases the necessary repetition number of adhesion steps of an oxidizing agent and a monomer of a conducting polymer to a dielectric of the capacitor while keeping the coverage ratio at a satisfactorily high level. A capacitor body with an oxide layer is first immersed into an oxidizer solution at a room temperature under an atmospheric pressure. The oxidizer solution has a viscosity ranging from 100 to 500 cp at room temperature under the atmospheric pressure. Then, the oxidizer solution adhered to the oxide layer is dried to remove a solvent of the adhered solution and to leave the oxidizing agent on the oxide layer. The oxidizing agent left on the oxide layer is in solid phase at room temperature under the atmospheric pressure. The capacitor body with the oxide layer is immersed into a monomer of a conducting polymer. The monomer of the conducting polymer adhered to the oxide layer is polymerized by the oxidizer left on the oxide layer, thereby forming a layer of the conducting polymer on the oxide layer. These steps are repeated until a desired thickness of the polymer layer is accomplished.