To simplify an operation of mounting a package substrate to a circuit board by mounting the first plane of a connector to a conductive trace by thermoplastic resin bonding and mounting the second plane of the connector to the conductive pad of the circuit board by thermoplastic resin bonding in the same manner.

The first plane of the sphere of a connector 302 is connected to a conductive trace 312 by thermoplastic resin bonding, and the second plane of the sphere of the connector 302 15 connected to the conductive pad 310 of a circuit board 306 by thermoplastic resin bonding in the same manner. At that time, a preferable contact area for the conductive pad 310 and the conductive trace is decided by insulating material layers 316 and 314, respectively. Since a thermoplastic material 308 as thermoplastic resin does not require flux for cleaning the surface prior to bonding and no residue is left on the circuit board 306, an operation of mounting a package substrate 304 on the circuit board 306 is simplified.