PURPOSE: To prevent a protruding part tor fixation use on a mounting board from falling off when it is passed through a soldering tank by a method wherein the protruding part for fixation use is provided with a groove, for fixation use, which is coupled mechanically to the mounting board and is used to prevent the board from being detached and a difference in a size between a face closest to a sealing resin body of the groove and a face closest to the board of an external lead is specified.

CONSTITUTION: A protruding part 3 for fixation use is provided with a groove 4 for fixation use of a carved structure coupled mechanically to a mounting board 5. During this process, a difference δ in size between a face coming into contact with the board 5 of an external lead 2 and a bonding face of the groove 4 for fixation use and the board 5 is set at 0.1 to 0.3mm.