the related arts have difficulty in efficiently dissipating the heat generated by a resin - molded semiconductor element , and thus have the problem of thermal stress causing damage to the semiconductor element . to solve the problem , a semiconductor device of the preferred embodiments includes common leads coupled to an island , and a part of the common leads projects out from a resin seal body . the projecting common leads have a coupling portion . when mounting the semiconductor device , the common leads are bridged with brazing material . thus , the heat generated by an integrated circuit chip mounted on the island is dissipated through the common leads to the outside of the resin seal body . in the preferred embodiments of the invention , a further improvement in heat dissipation characteristics can be accomplished by increasing the surface areas of the common leads .