One of the major problems in conventional parallel-gap joining methods is overheating. Damage to the copper circuit thus results. The BWRA has designed a new electrode with a metallic insert. The insert which is separated from the electrodes by a thin dielectric acts as a heat sink. Joints made with the new electrode have a large bond area, show little damage to the substrate, and exhibit a characteristic fillet at the edge of the lead. This fillet is a visual indication of a satisfactory joint.