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, stru cture, mechanical and electrical characteristics of the new proposed Cu-Sn metallurgical alloy, which may be used in electronic joins. By proper choic e of process temperature and pressure. Cu coated surfaces are soldered usin g 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 thicknes s (d(Sn)) needed is slightly above 7 mum. Due to join wettability, higher t emperatures (between 523 and 573 K) and d(Sn) above 35 mum are required to form joins within the specifications of the electronic industry. (C) 2000 P ublished by Elsevier Science B.V.