Patent ID: 8202457

Claim:
A method for producing a battery pack, comprising a step (a) of forming a molded part between an end face of a secondary battery on a seal plate side and a circuit board disposed so as to face the end face thereof, to produce a battery pack intermediate product comprising the secondary battery and the circuit board which are joined integrally, wherein the step (a) includes: a step (b) of bringing a nozzle into contact with a molding material injection inlet of a mold for forming the molded part, the nozzle being provided for feeding a molding material comprising a resin of polyamide adhesive or polyurethane adhesive to the mold; a step (c) of, after the formation of the molded part, moving the nozzle away from the molding material injection inlet to cut off, from the nozzle, solidified resin that is formed by solidification of the molding material in a runner system of the mold connected to the molding material injection inlet; and a step (d) of applying a predetermined tensile stress to the solidified resin and maintaining this state for a predetermined time to separate the solidified resin bonded to an inner surface of the runner system therefrom, the step (d) being performed as a pretreatment for the step (c); wherein the runner system comprises a sprue connected to the molding material injection inlet and a plurality of runners branching off from the sprue, the step (d) is a step of separating solidified resin formed in the sprue by solidification of the molding material and bonded to an inner surface of the sprue therefrom, and the step (d) is performed by moving a sprue bushing having the sprue and the nozzle away from a runner stripper plate holding solidified resin formed in the runners by solidification of the molding material for a predetermined distance, and maintaining this state for a predetermined time.