Abstract Scope |
The ability of a surface to be wetted and to form a solder joint is referred to as solderability. Good solderability requires spreading and wetting of molten solder on the substrate. Solderability of an alloy can be quantified by wetting balance test (immersion method), and sessile drop test (spread method). In this work, the solderability of few lead-free solders, Sn, Sn-Cu, Sn-Bi, Sn-Cu-Bi and Sn-Cu-Bi-Ag systems, is assessed. Kinetics of wetting, wetting force and contact angle are measured and the effects of alloying elements are discussed. It is demonstrated that to measure and compare the solderability of alloys, it is essential to consider the thermal behaviour of the solder alloys as well. |