Battery tab attachment method

Abstract

The difficulties encountered with attaching tabs to very thin metal layer. e. g., a layer of gold from 0.3 μm to 50 μm thick are severe. Typically, in the uses envisioned for the thin metal layer, which is for a compact battery, a plastic sheet such as polyimide underlies the thin metal layer. Polyimide has a relatively low melting point. The thin polyimide substrate melts when resistance welding is used. Ultrasonic welding doesn't work because the sound wave energy is absorbed by the polyimide. This invention solves the attachment problem by using wire bonding to the thin metal sheet and to its tab. The tab attachment for a thin metal layer comprises a thin metal layer, a metal tab, and a wire and the wire is bonded to the thin metal layer and the wire is bonded to the metal tab. The thin metal layer may be gold; the thickness of the gold is between 0.3 μm and 50.0 μm.

Dependencies are inferred from the claim text.