| abstract |
A substrate (10) has a first surface and a second surface (11, 12). A plurality of contact points (21-23) are formed on at least one of the first and second surfaces. Each pad has a Cu plating layer and an Au plating layer which is formed directly on the Cu plating layer. An Al wiring (61) or an Au wiring (60) is bonded to the contact points. The thickness of the Au plating layer to which the Al wiring is bonded is less than 0.5 µm. The thickness of the Au plating layer to which the Au wiring is bonded is 0.05 µm or more. |