FOIL MATERIAL FOR AL ELECTROLYTIC CAPACITOR ANODE WHERE ENLARGEMENT OF SURFACE AREA BY ELECTROLYTIC ETCHING PROCESSING IS REMARKABLE

摘要

PROBLEM TO BE SOLVED: To provide a foil material for an Al electrolytic capacitor anode where the enlargement of the surface area by electrolytic etching processing is remarkable. SOLUTION: Foil material is constituted by forming surface reactive layers which have structures where intermetallic compound grains of Cu and Al are dispersed and distributed in Al basis material, on the surface of both sides of pure Al foil material 99.95% or over in purity, and the said intermetallic compound grains in the said surface reactive layer are all 0.5μm or under in maximum diameter within grain and besides the ones within the range of 0.05-0.5μm in maximum diameter within grain exist by 5-200 pieces per 100μm<2> , when the structure of the foil surface is observed and a scanning electron microscope.