A module substrate has an interconnection electrode that is exposed at a side end face thereof. A semiconductor component including an IC chip is mounted on the module substrate. A molded part comprising a resin is formed so as to cover at least a part of the semiconductor component. A coating with higher heat conductivity than the molded part is formed on the surface of the molded part by applying a paste made of material with higher heat conductivity than the molded part. This improves heat dissipation. The coating can be formed such that it extends to the surface of the main substrate on which the module substrate with the semiconductor component is mounted and comes into contact with the interconnection electrode on the surface of the main substrate. This further improves heat dissipation.