Published June 12, 2008 | Version v1
Journal article

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

  • 1. Department of Microtechnology and Nanoscience, Bionano Systems Laboratory, Chalmers University of Technology, and Sino Swedish Microsystem Integration Technology (SMIT) Center, Kemivaegen 9, Se-412 96, Gothenburg (Sweden)
  • 2. Key State Lab for New Displays and System Applications and SMIT Center, Shanghai University, Box 282, Yanchang Road 149, Shanghai 200072 (China)

Description

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 deg. 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 oC for 24 h. The eutectic Sn-0.7Cu-0.4Co solder alloy can therefore be a very good alternative for the SAC alloys for surface mount technology applications

Availability note (English)

Available from http://dx.doi.org/10.1016/j.jallcom.2007.03.028

Additional details

Identifiers

DOI
10.1016/j.jallcom.2007.03.028;
PII
S0925-8388(07)00624-X;

Publishing Information

Journal Title
Journal of Alloys and Compounds
Journal Volume
457
Journal Issue
1-2
Journal Page Range
p. 97-105
ISSN
0925-8388
CODEN
JALCEU

Optional Information

Copyright
Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.