| 摘要 |
A coating for an electrical chip board consists of a Ni (alloy) layer, a Pd (alloy) layer and a Au (alloy) layer with the latter layer having a thickness of 0.-1-0.5 mu m. Pref. the Ni (alloy) layer has a thickness of 1-10 mu m., pref. 2 mu m., the Pd (alloy) layer a thickness of 0.01-0.5 mu m. pref. 0.05-0.2, the pref. thickness of the Au (alloy) layer is 0.05-0.1 mu m. The Au alloy may be Au-Fe, Au-Co or Au-Ni. The Ni alloy may be Ni-B, Ni-P, Ni-Fe-P, Ni-P-W, Ni-Co-P or Ni-W. The Pd alloy may be Pd-Ni with 10-40 wt.% Ni or Pd-Ag with 10-50 wt.% Ag and an adhesive underlayer of 0.01-0.1 mu m Pd. The substrate is made of Cu, Ni or alloys of these or a Cu metallised polyimide or glass fibre reinforced epoxy resin. |
