Reactive wetting of solders on Cu and Cu 6Sn 5/Cu 3Sn/Cu substrates was investigated using both (1) the wetting balance, and (2) the hot-stage real time, in situ visualization of the triple-line movement. To understand the phenomenology of the spreading behavior better, comprehensive real-time in situ observations were performed. It was found that the wetting time during the wetting balance tests for both the lead solder (63SnPb) and lead-free solder systems (Sn0.7Cu and Sn3.5Ag) is shorter on Cu substrates than it is on Cu 6Sn 5/Cu 3Sn/Cu substrates. The wetting force was not remarkably different on these two substrates for the same solder system. The hot-stage tests indicate a more pronounced spreading of 63Sn-Pb on Cu 6Sn 5/Cu 3Sn/Cu substrates, along with a much larger spreading area. Spreading of lead-free solders in terms of the triple-line kinetics studied by using the hot-stage visualization shows no significant difference in the spreading evolution either over Cu or over Cu 6Sn 5/Cu 3Sn/Cu substrates.
|Number of pages||8|
|Journal||Journal of Electronic Materials|
|State||Published - Oct 2008|
Bibliographical noteFunding Information:
This work has been funded through a grant from Kentucky Science and Engineering Foundation (Grant Nos. KSEF-829-RDE-007 and KSEF-1490-RDE-010). One of the authors (H. Wang) acknowledges the visiting scholarship support from the University of Kentucky Center for Manufacturing.
- Lead-free solders
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering