PURPOSE: To acquire a connection structure of a terminal which is suitable for formation of a solder fillet by making solder positioned between an electrode and a terminal lead creep over an upper side of a terminal lead when the terminal lead and an electrode formed on a substrate are thermally compressed by soldering.

CONSTITUTION: Solder 7 is arranged between a projecting terminal lead 3 and an electrode 6 of a printed circuit board, and thermocompression 72 is performed for a wide lead central part 32; then, the solder 7 goes toward an arrow 73 from a narrow part formed in both end parts 33 of the lead and creeps over an upper side of the end parts 33. A solder fillet can be formed on the both end parts 33 of the lead.