| 摘要 |
In one embodiment, the via hole comprises a sputtered metal layer 8 on which a second metal layer 7, eg of Ni-base alloy, is deposited by electroless-plating. A third metal layer 9, eg of Au, is deposited on the second metal layer by electroplating. In alternative embodiments, (Figs 2 - 8), the first metal layer is deposited by electroless plating, the second metal layer is sputtered on the first layer and the third metal layer is electroplated on the second layer. Since the inner surface of the hole is completely covered with the sputtered and electroless plated layers, the thick low resistance metal layer 9 can be electroplated over the inner surface of the hole without discontinuity. Further, since the sputtered and electroless plated layers have a good adhesion to the inner surface of the hole, the electroplated layer 9 is formed with a good adhesion. <IMAGE> |
