You are not logged in Total: 7journals, 20,213articles Online
Login / Register
Forgot Login?
Main menuMain menu
What's new
Journal list
Visiting ranking
Phrase ranking
About us
Journal Site
Advanced Search

Home  >  Journal list  >  MATERIALS TRANSACTIONS  >  Vol.43  No.8 (2002)  >  pp.1827-1832

<<Previous article Vol.43  No.8 (2002)   pp.1827 - 1832 Next article>>

Effects of Alloying in Near-Eutectic Tin-Silver-Copper Solder Joints

Iver E. Anderson1), Bruce A. Cook1), Joel Harringa1), Robert L. Terpstra1), James C. Foley1) and Ozer Unal1)
1) Ames Laboratory, Iowa State University

This study included a comparison of the baseline Sn–3.5Ag eutectic to one near-eutectic ternary alloy, Sn–3.6Ag–1.0Cu and two quaternary alloys, Sn–3.6Ag–1.0Cu–0.15Co and Sn–3.6Ag–1.0Cu–0.45Co, to increase understanding of the effects of Co on Sn–Ag–Cu solder joints cooled at 1–3°C/s., typical of reflow assembly practice. The results revealed joint microstructure refinement due to Co-enhanced nucleation of the Cu6Sn5 phase in the solder matrix, as suggested by Auger elemental mapping and calorimetric measurements. The Co also reduced intermetallic interface faceting and improved the ability of the solder joint samples to maintain their shear strength after aging for 72 h at 150°C. Some recent additional results with Co and Fe additions are consistent with this catalysis effect, where a reduced total solute level was tested. The baseline Sn–3.5Ag joints exhibited significantly reduced strength retention and coarser microstructures.

lead-free solder, tin (Sn)-silver (Ag)-copper (Cu) solders, joint shear strength, joint microstructure, solder joint solidification

Received: April 30, 2002
Accepted: July 10, 2002 , Published online: September 06, 2005
Copyright (c) 2005 The Japan Institute of Metals



Terms of Use | Privacy Policy