To significantly reduce a heat escape amount at the time of soldering and improve a soldering rate by providing a recessed groove for heat insulation around the mounting hole part for soldering a connecting part of an electroconducting lead part.

A lead frame insert molded part has a notched part 4 around the mounting hole part 2 for soldering a connecting part of an electroconducting lead part 1. As the notched part 4 is provided around the mounting hole part 2, a soldering head is shut off by the notched part 4 when the connecting part is soldered in the mounting hole part 2. Consequently, the soldering heat is effectively controlled. As the effective control of the escape of the soldering heat is achieved around the mounting hole part 2, it is possible to rapidly heat the mounting hole part 2, and solder the connecting part rapidly and easily with high reliability.