Patent ID: 12002965

Abstract:
Provided is a long aluminum foil capable of suppressing, in a case where the aluminum foil is provided with a region where through-holes are not formed, occurrence of deformation at a boundary portion between a region where through-holes are formed and the region where through-holes are not formed. The long aluminum foil includes, in a width direction orthogonal to a longitudinal direction, a perforated portion, a non-perforated portion, and a boundary portion between the perforated portion and the non-perforated portion, in which the perforated portion has a plurality of through-holes penetrating therethrough in a thickness direction, the non-perforated portion does not have a through-hole, the boundary portion has a plurality of through-holes penetrating therethrough in the thickness direction and a plurality of non-through-holes, and an opening ratio of the through-hole in the boundary portion gradually decreases from a perforated portion side to a non-perforated portion side.