A first surface of a double-sided printed circuit board has a soldering land for heat radiation, which serves as a mounting surface for an electronic part. A land for solder absorption is formed on the second surface facing the mounting surface. Viaholes are provided and open in both the soldering land for heat radiation and the land for solder absorption at the opposite ends. Molten solder flows out from the openings of the viaholes and spreads on the land for solder absorption to suppress formation of solder balls. Cream solder is applied to the outer surface of the land for solder absorption to embed the solder and to form a solder layer.