THERMAL FUSE SERVING AS CURRENT FUSE PREVENTING RUSH CURRENT

摘要

PURPOSE: A thermal fuse serving as a current fuse is provided to prevent a rush current situation by suppressing a variation of a thickness of the fuse or of an operational temperature. CONSTITUTION: A thermal fuse includes a low-melting point fusible alloy piece(2) having an alloy composition containing 40 to 70% Bi and connected between a pair of flat lead conductors(1). A flux(4) is applied to the low-melting pointing fusible alloy piece. The flux-applied low-melting point fusible alloy piece is inserted between a resin base film(31) and a resin cover film(32) so as to implement an electric insulation. A resistance of the low-melting point fusible alloy piece is set so as to enable the low-melting point fusible alloy piece to be fused off also by a Joule heat due to an allowable maximum current from a secondary battery.