Production of low cost contacts and joins for large area devices by electrodeposition of Cu and Sn

The aim of this paper is to present results concerning the morphology, structure, mechanical and electrical characteristics of the new proposed Cu±Sn metallurgical alloy, which may be used in electronic joins. By proper choice of process temperature and pressure, Cu coated surfaces are soldered using Sn as pre-form. The main results achieved indicate that the formation of Cu3Sn phase begins at a temperature of about 473 K and that the Sn thickness (dSn) needed is slightly above 7 mm. Due to join wettability, higher temperatures (between 523 and 573 K) and dSn above 35 mm are required to form joins within the speci®cations of the electronic industry. # 2000 Published by Elsevier Science B.V.