Spreading kinetics of liquid solders over an intermetallic solid surface. Part 2: Lead-free solders

H. Zhao, H. Q. Wang, D. P. Sekulic, Y. Y. Qian

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


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.

Original languageEnglish
Pages (from-to)1846-1854
Number of pages9
JournalJournal of Electronic Materials
Issue number9
StatePublished - Sep 2009

Bibliographical note

Funding Information:
This work has been funded through grants from the Kentucky Science and Engineering Foundation # KSEF-829-RDE-007 and KSEF-1490-RDE-010.


  • Intermetallics
  • Lead-free solders
  • Spreading

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Materials Chemistry
  • Electrical and Electronic Engineering


Dive into the research topics of 'Spreading kinetics of liquid solders over an intermetallic solid surface. Part 2: Lead-free solders'. Together they form a unique fingerprint.

Cite this