PURPOSE: To enhance a heat efficiency at the bonding operation of a lead and to prevent the dislocation and the thermal deterioration of an electronic component by a method wherein the whole region or at least a partial region other than a bonding region which is bonded to other electronic circuit elements on the surface of the lead is covered with a material whose heat radiation coefficient is high.

CONSTITUTION: The whole region or at least a partial region other than a bonding region 4a on the surface of a lead 4 is covered with a high-heat- radiation-coefficient layer 5. Thereby, the bonding region 4a of the lead 4 is brought into contact with other electronic circuit elements such as an interconnection pad 7 and the like. When the high-heat-radiation-coefficient layer 5 is irradiated with a laser beam α, the laser beam α is absorbed efficiently, and the lead 4 can be bonded to the other electronic circuit elements in a short time. Since the lead 4 is covered with the high-heat-radiation-coefficient layer 5, heat is dissipated well immediately after a bonding operation, and the cooling speed of the lead 4 is large. Thereby, a heat efficiency can be enhanced at the bonding operation of the lead, and it is possible to prevent the dislocation and the thermal deterioration of an electronic component.