Patent ID: 7189630
Filing Date: 2007-03-13
Classification: C23C,H01L,H01R,H05K

Abstract:
1. A layer sequence on a substrate made from copper or a copper-based alloy, made from nickel or a nickel-based alloy or a copper-plated substrate, to produce a composite material, comprising: a covering layer consisting of tin or a tin-based alloy, which is arranged at least over part of the substrate; a barrier layer, which is located between the substrate and the covering layer and is in direct contact with the substrate, the barrier layer consisting of at least one element selected from the group consisting of Fe, Co, Nb, Mo or Ta; an intermediate layer , which is located between the barrier layer and the covering layer and is in direct contact with the barrier layer, the intermediate layer consisting of at least one element selected from the group consisting of Cu and Ni; and a reaction layer which is located between the covering layer and the intermediate layer, the reaction layer consisting of Ag or an Ag alloy, of Pt or Pd or their alloys, the reaction layer having a thickness which corresponds to a ratio of between 1/3 to 1/1 of the thickness of the covering layer.