Electrode for electrolytic capacitor

Abstract

An anodic electrode for an electrolytic capacitor having high capacitance with low-resistance properties at high frequencies and capable of carrying large current, and a process of producing the same. Such an anodic electrode for electrolytic capacitor includes a porous body having micropores to be formed with a dielectric layer therein and to be filled with electrolyte therein, wherein the porous body includes a laminate of a plurality of sinter layers having the micropores formed from valve metal particles. The laminate includes multilaminarly smaller micropore-size regions and larger micropore-size regions to form electric conductive passages between the small micropore-size regions and side surfaces of the porous body to reduce resistance of the capacitor and also increase capacitance by utilizing the smaller micropores-size regions for capacitor effectively. The porous body is formed by stacking a plurality of porous preforms such as sheets preformed of valve metal powder into a laminate, and then sintering the laminate. The porous body may be joined with a valve metal substrate during sintering, thereby completing the anodic electrode for an electrolytic capacitor. Particularly, the porous body may be a laminate including large micropore-size sinter layers and small micropore size sinter layers, by alternatively laminating two types of preforms different in density.