Tensile properties and microstructural characterization of Sn-0.7Cu-0.4Co bulk solder alloy for electronics applications
Journal article, 2008

The ternary Sn–Cu–Co system eutectic composition was obtained by means of CALPHAD (CALculation of PHAse Diagram) methodology and it was found to be 0.4% Co and 0.7% Cu (wt%) with a melting point of 224 ◦C. The tensile behavior of this alloy was investigated at different strain rates (10−5, 10−4 and 10−3 s−1) and compared to both Sn–37Pb and Sn–4.0Ag–0.5Cu. The Sn–4.0Ag–0.5Cu alloy depicts the highest ultimate tensile strength (UTS) followed by the Sn–37P and finally the Sn–0.7Cu–0.4Co system. The elastic modulus was also higher for the Sn–4.0Ag–0.5Cu followed by the Sn–0.7Cu–0.4Co and last the Sn–37Pb. The microstructure of the Sn–0.7Cu–0.4Co alloy is composed of two types of intermetallic phases, (Cu,Co)6Sn5 and (Co,Cu)Sn2 dispersed in a Sn-rich matrix. The microstructure of this alloy proved to be very stable, after aging at 150 °C for 24 h. The eutectic Sn–0.7Cu–0.4Co solder alloy can therefore be a very good alternative for theSACalloys for surface mount technology applications.

Lead-free

Tensile properties

Strain rate

Solder alloy

Sn-Cu-Co

Author

Cristina Andersson

Chalmers, Applied Physics, Electronics Material and Systems Laboratory

Peng Sun

Chalmers, Applied Physics, Electronics Material and Systems Laboratory

Johan Liu

Chalmers, Applied Physics, Electronics Material and Systems Laboratory

Journal of Alloys and Compounds

0925-8388 (ISSN)

Vol. 457 1/2 97-105

Subject Categories

Other Materials Engineering

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1016/j.jallcom.2007.03.028

More information

Created

10/7/2017