Douglass S. Kalika, David W. Giles, et al.
Journal of Rheology
The microstructure property relations of several Pb-free solders are investigated to understand the microstructural changes during thermal and mechanical processes of Pb-free solders. The Pb-free solder alloys investigated include pure Sn, Sn-0.7% Cu, Sn-3.5% Ag, and Sn-3.8% Ag-0.7% Cu (in weight percent). To reproduce a typical microstructure observed in solder joints, the cooling rate, ingot size, and reflow conditions of cast alloys were carefully controlled. The cast-alloy pellets are subjected to compressive deformation up to 50% and annealing at 150°C for 48 h. The microstructure of Pb-free solders is evaluated as a function of alloy composition, plastic deformation, and annealing. The changes in mechanical property are measured by a microhardness test. The work hardening in Sn-based alloys is found to increase as the amount of alloying elements and/or deformation increases. The changes in microhardness upon deformation and annealing are correlated with the microstructural changes, such as recrystallization or grain growth, in Pb-free solder alloys.
Douglass S. Kalika, David W. Giles, et al.
Journal of Rheology
R.M. Macfarlane, R.L. Cone
Physical Review B - CMMP
A. Ney, R. Rajaram, et al.
Journal of Magnetism and Magnetic Materials
E. Babich, J. Paraszczak, et al.
Microelectronic Engineering