MANUFACTURE OF ALUMINUM FOIL FOR USE IN HIGH PLATE VOLTAGE OF ELECTROLYTIC CAPACITOR

摘要

PURPOSE:To increase the rate of integration of cubic orientation crystalline grains and to improve the capacitance of electrolytic capacitor using the foil mentioned below, by regulating the surface roughness of an Al foil after rolling to a prescribed value or below in foil rolling just before process annealing. CONSTITUTION:A sheet metal of Al is rolled into foil by means of rolls whose surface roughness is controlled, which is subjected to process annealing. Then the Al foil is cold-rolled by means of rolls whose surface roughness is controlled in a similar manner as above, followed by finish annealing. Owing to both rollings mentioned above, the roughness of the Al foil surface is finely adjusted and the value of center line average height (Ra) of the foil in a direction perpendicular to the rolling direction is regulated to <=0.35mum.