PURPOSE: To reduce the stress of a connecting pad and prevent the increase of stress while a substrate passses through the heat processing by forming Cu layer as a low stress layer with the plating including an organic compound or carbonic acid gas and forming Ni as a low stress storing layer with the plating.

CONSTITUTION: A Cr/Cu/Cr film is formed as a bonding layer/electrically plated power feeding layer/bonding layer by the sputtering on a wiring substrate 5. Next, a guide film during formation of a plating film pattern is formed. As the guide film, a photoresit film or organic resin film 9 is used. Moreover, the Cr film at the bottom part of guide is etched and electric Cu, Ni platings are performed. In this case, in view of reserving low stress of the Cu film 11, the Ni plating 10 must be executed immediately after the Cu plating 11. Next, the plating guide film 9 is removed and the patterning of the bonding layer/ electric plating power feeding layer is executed. Finally, electroless Au plating 12 is conducted on the Ni 10 as the oxidation preventing layer.