PURPOSE: To produce a miniature high capacity solid electrolytic capacitor having improved tanδ, leakage current, and high frequency characteristics by forming ruthenium dioxide even in micropores.
CONSTITUTION: An anodic oxidation film 2 formed on a porous electrode body 1 of valve metal is impregnated with an aqueous solution of ruthenium nitrate added with a surfactant. It is then thermally decomposed to form a ruthenium oxide layer 3. Since ruthenium oxide adheres to the entire surface of anodic oxidation film, the coverage is increased to provide high capacity and since the quantity of ruthenium oxide having function for repairing the oxide film increases on the interface between the oxide film and ruthenium oxide increases, the leakage current is decreased. Furthermore, the pores are filled sufficiently with ruthenium oxide to widen the conduction path and decreases the resistance thus realizing an excellent solid electrolytic capacitor having improved tanδ and decreased high frequency impedance.
TANAHASHI MASAKAZU
NAKADA YASUHIKO
OKANO TETSUYUKI
MURAKAMI YOSHIKI
