abstract |
The invention relates to a substrate having a bondable metal coating comprising, in this order, on an Al or Cu surface: (a) a Ni—P layer, (b) a Pd layer and, optionally, (c) an Au layer, wherein the thickness of the Ni—P layer (a) is 0.2 to 10 m, the thickness of the Pd layer (b) is 0.05 to 1.0 m and the thickness of the optional Au layer (c) is 0.01 to 0.5 m, and wherein the Ni—P layer (a) has a P content of 10.5 to 14 wt.-%. The deposit internal stress of the resulting Ni—P/Pd stack is not higher than 34.48M−Pa (5,000 psi). Further, a process for the preparation of such a substrate is described. |