Production of electrode for aluminum electrolytic capacitor

Abstract

Abstract PURPOSE: To form an aluminum electrode foil of a high surface expansion rate and tensile strength by letting sulfuric acid exist in a high-concentration high-temperature hydrochloric acid solution ans applying DC electrolytic etching under the specific conditions. CONSTITUTION: At the time of expanding the surface area of an Al metal foil through electrolytic etching, sulfuric acid is added at 0.1W0.3% into the bath of HCl concentrations 3W15%, and while the solution temperature is being maintained at 80°C or more, the foil is pretreated by using the electric quantity of DC 2W30 Coulomb/cm 2 , after which it is subjected to deep etching at current density 0.02W 0.1A/cm 2 DC at the same temperature, whereby the pits of diameters made 4 timers larger than those by conventional methods are formed. Because of this, the decrease in surface expansion rate in the high pressure region is small and since the shape of the pits becomes perpendicular and regular cylindrical form, the surface expansion rate becomes extremely high. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Tadashi Yamazaki

Bibliographic Details