Sn-3.5Ag eutectic and Sn-5Sb solid solutionalloy are considered potential alternate materials for replacinglead-based solder materials in electronic packaging.Deformation behavior of pure tin metal, Sn-3.5Ag and Sn-5Sballoys was investigated between ambient and 473 K fromconstant load creep tests. Power-law stress dependence wasobeyed by all the materials with stress exponent n valence 7.6for pure tin, and n valence 5 for Sn-3.5Ag and Sn-5Sb alloys.Activation energy for creep deformation was estimated to beequal to 64 kJ/mole for pure tin, 66 kJ/mole for Sn-3.5Ag and44 kJ/mole for Sn-5Sb alloys. Based on the stress exponent andactivation energy values, it is suggested that the creepdeformation mechanisms are dislocation creep controlled bylattice diffusion in pure tin and Sn-3.5Ag, and viscous glidecontrolled by pipe diffusion in Sn-5Sb alloy.
展开▼
