Microstructure coarsening during static annealing of 60Sn4OPb solder joints: II eutectic coarsening kinetics

The eutectic coarsening kinetics for 60Sn40Pb solder joints annealed at 50 degreesC to 150 degreesC was determined to be of the form (D) over bar (n)-(D) over bar (n)(o) = K-0 exp (-Q/RT)t where (D) over bar is the mean linear intercept phase size, (d) over bar (o ) approximate to 1.0 mum the as-reflowed phase size, n = 4.1 +/-0.15, Q = 3 9.8 +/-0.8 kJ/mole, K-o = 1x10(-23) -4.5x10(-23) m(4)/s, and t the time. Th e magnitude of the phase size exponent, n, and the parameters, K-o, and Q, are in accord with the models by Senkov and Myshlyaev and by Ardell for pha se coarsening controlled by grain boundary or interfacial solute diffusion. The phase shape factor did not have a significant influence on the coarsen ing kinetics.