Abstract: A method for manufacturing an electronic device for signal transmission includes winding a wire of at least one electronic element onto a winding portion of an inner terminal of a lead of a packaging casing, displacing the at least one electronic element away from the inner terminal to a side of the packaging casing that is distal to the inner terminal, immersing the winding portion of the inner terminal and the wire in a bath of molten solder, and removing the inner terminal and the wire from the bath of the molten solder so that the winding portion of the inner terminal forms a welded portion for reliably and electrically connecting the inner terminal to the wire. Preferably, electrical connection between the inner terminal and the wire is tested after the step of removing the inner terminal and the wire from the bath of the molten solder.