Tin coated electrical connector
AssigneeOlin Corporation
InventorsJulius C. Fister, Szuchain Chen, Abid A. Khan, Dale L. Bender
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Abstract
An electrical conductor has a copper base substrate coated with a tin base coating layer. To inhibit the diffusion of copper from the substrate into the coating layer and the consequential formation of a brittle tin/copper intermetallic, a barrier layer is interposed between the substrate and the coating layer. This barrier layer contains from 20% to 40%, by weight, of nickel and is preferably predominantly comprised of copper. In one embodiment, an intermetallic layer selected from the group (Cu--Ni).sub.3 Sn, (Cu--Ni).sub.6 Sn.sub.5, Cu.sub.3 Sn, Cu.sub.6 Sn.sub.5 is disposed between the barrier layer and the tin base coating layer.
Claims8
A composite material, comprising:
- a copper or a copper base alloy substrate;
- a coating layer consisting of tin or a tin base alloy overlying a portion of said substrate;
- an electroplated barrier layer interposed between said substrate and said coating layer directly contacting said coating layer, said barrier layer containing from 20% to 40%, by weight, of nickel and having a thickness of between 0.2 and 5 microns and
- a metallic flash disposed between said substrate and said barrier layer and in direct contact with both said substrate and said barrier layer, said metallic flash having a thickness of from 2 microinches to 50 microinches.
A composite material, comprising:
- a copper or a copper base alloy substrate;
- a coating layer consisting of tin or a tin base alloy overlying a portion of said substrate;
- an electroplated barrier layer interposed between said substrate and said coating layer directly contacting said coating layer said barrier layer containing from 20% to 40%, by weight, of nickel and having a thickness of between 0.2 and 5 microns;
- and
- a copper-tin intermetallic dispersed in said coating layer, said intermetallic having a flattened obelisk shape.
Dependencies are inferred from the claim text.