A thermodynamics model for solder profile evolution

A thermodynamics model for describing the solder profile evolution and the triple point line motion driven by surface tensions and gravity held is pro posed. Attention is focused on the kinetic process as the solder profile ev olves toward its equilibrium shape in its molten state. Based upon non-equi librium thermodynamics, a theoretical model is proposed by introducing the kinetic laws that characterize the motions of the solder surface and the tr iple point line. The presented model leads to a nonlinear dynamic system, w hich describes the entire time-dependent process of the solder wetting. It can be applied not only to predict the equilibrium shape of the solder, but also the shape at any time during the spreading process. A computer numeri cal simulation and examples for the solution of the dynamic system are desc ribed. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. A ll rights reserved.