Influence of environment on the fatigue of Pb-Sn solder joints

Microstructure coarsening during static annealing of 60Sn40Pb solder joints: III intermetallic compound growth kientics

“…This subject is important regarding low-cycle fatigue of Sn-Pb alloy solder joints, since in general the fatigue crack occurs either in the solder immediately adjacent to intermetallic compound or within the compound itself. [1][2][3][4][5][6] The solid state growth of an intermetallic compound layer (IC) which occurs during annealing is generally considered in terms of the relation 1,6-13 h = h o + A t p = h o + A o exp(-Q a /RT)t p (1) where h is the thickness at time, t, h o the initial thickness, Q a an apparent activation energy, and A o and p are constants. For a bulk diffusion growth process, one expects…”