Patent ID: 8749955

Claim:
A capacitor comprising: a substrate made of a valve metal, and having a first face and a second face confronting each other; a porous first rough surface layer formed by depositing a valve metal on the first face and having pores on its outer surface and inside; a first inner conductive polymer layer formed in the pores of the first rough surface layer; a first outer conductive polymer layer formed on the outer surface of the first rough surface layer; a second rough surface layer formed by depositing a valve metal on the second face and having pores on its outer surface and inside; a second inner conductive polymer layer formed in the pores of the second rough surface layer; a second outer conductive polymer layer formed on the outer surface of the second rough surface layer; and a dielectric film formed on a surface of the first rough surface layer and a surface of the second rough surface layer, wherein a surface area of the second rough surface layer is smaller than a surface area of the first rough surface layer, and the second outer conductive polymer layer is thicker than the first outer conductive polymer layer.