This study is devoted to a phenomenological and quantitative investigation of the physics of spreading of lead-free solder systems (Sn, Sn-0.7Cu, and Sn-3.5Ag) over Cu 6Sn 5/Cu 3Sn/Cu substrates. Wetting kinetics was studied using real-time in situ monitoring of the triple-line kinetics under a controlled atmosphere. Three different intermetallic (IMC) substrates were used for this investigation. It was found that the grain size of the deposited IMC compound coating has a sizable influence on the triple-line movement of the liquid solders considered. More pronounced spreading of solders on IMC substrates was observed for all lead-free solders over an intermetallic with the smallest grain size. Lead-free solder spreading over IMC surfaces exposed to aging at elevated temperatures, hence featuring larger grain size, did not feature a significant improvement of wettability when compared with the behavior of the same solders on virgin copper substrates.
|Number of pages||9|
|Journal||Journal of Electronic Materials|
|State||Published - Sep 2009|
Bibliographical noteFunding Information:
This work has been funded through grants from the Kentucky Science and Engineering Foundation # KSEF-829-RDE-007 and KSEF-1490-RDE-010.
- Lead-free solders
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering