Electrical conductor made of copper-plated and tin-plated aluminum

An electrical conductor comprising:

• a central core comprised of aluminum, said central core having a thickness between 0.08 and 2.0 millimeters (mm);
• and
• a metal coating on said central core which is resistant to oxidation and is brazable, said metal coating comprising an underlayer of copper having a thickness between 0.5 and 15 micrometers (.mu.m), and a layer of tin having a thickness between 0.5 and 15 micrometers (.mu.m);
• wherein the wetting angle formed between the surface of the electrical conductor and a surface of a meniscus of a solder at their point of junction is between 10.degree. and 60.degree..

An electrical conductor comprising:

• a central core comprised of aluminum, said central core having bonding points in the form of microscopic metal seeds formed by, successively with intermediate rinsings, degreasing of the core, pickling and surface treatment;
• and
• a metal coating on said central core which is resistant to oxidation, is brazable, and has a wetting angle between 10.degree. and 60.degree., said metal coating being applied by a process comprising the following steps:
• electronchemically depositing copper on the conductor in a first aqueous bath maintained at a temperature of between 20.degree. C. and 60.degree. C., containing KCN, CuCN, K.sub.2 CO.sub.3 and KNaC.sub.4 H.sub.4 O.sub.6 with a current intensity of between 1 and 10 Amperes per square decimeter (A/dm.sup.2),
• rinising the conductor at ambient temperature,
• electrochemically depositing tin on the conductor in a second aqueous bath maintained at a temperature of between 20.degree. C. and 60.degree. C., containing essentially tin and methanesulphonic acid and, optionally, additives, with a current intensity of between 1 and 100A/dm.sup.2, and
• rinising the conductor with water at 60.degree. C.