<p>A circuit board (A1) includes an insulative substrate (1), a conductive pad (4a) formed on the substrate, and a metal piece (3) bonded to the pad via a solder layer (6). The metal piece (3) has a welding portion (3a) to which an external-connection terminal (5) is welded. A gap (7) is provided between the welding portion (3a) and the substrate (1). The welding portion (3a) and the solder layer (6) are separated by the gap (7).</p>
