PROCESS AND DEVICE FOR FORMING SECONDARY-CELL GAS VENTING HOLE

摘要

A degassing hole is formed in a casing in which a storage element is housed. Prior to forming the degassing hole, the casing is clamped in a region between the outer peripheral edge of the casing and the strage element where the degassing hole is to be formed such that overlapped films of the casing are pressed tightly together. By displacing the acting position of the clamping force toward the storage element while reducing the clamping force gradually toward the storage element prevent, liquid spill in a degassing process is prevented.