Sn-Rich Phase Coarsening in Sn-Ag-Cu Solder Joint during Moderate Current Stressing
The changes of microstructure in eutectic sn-3.8ag-0.7cu during moderate current stressing have been investigated. The current stressing values were 102 and 103 a/cm2. The tests were carried out for 24, 216, 576 and 1008 hours. Sn-rich phases and eutectic phases appear immediately after soldering process. However, thermal rise during current stressing has coarsened sn-rich phases and altered the microstructure of the solder. Higher current density leads to larger snrich phase coarsening. The microstructures for current stressing test were also compared with the series of microstructure for isothermal annealing test since there is similarity in coarsening effect for both tests. The effect of thermal rising during current stressing as well as during isothermal annealing to sn-rich phase coarsening is established and will be discussed further.
M.S.J. Hashmi, S. Mridha and S. Naher
N. Saud and A. Jalar, "Sn-Rich Phase Coarsening in Sn-Ag-Cu Solder Joint during Moderate Current Stressing", Advanced Materials Research, Vols. 264-265, pp. 212-216, 2011