Abstract
An approximate method is developed to determine the effect of pad dimensions, component dimensions, conveyor angle and solder properties (surface tension and density) on the size and shape of solder joints formed during a wave soldering process. The model uses a dipping analogy to simulate the wave soldering operation, and is thus also applicable to dipping processes for soldering, pre-tinning or bumping. The study represents an extension of previous work by the authors in which the effect of conveyor angle was not included and the exact solution for the molten solder capillary surface was utilized. In the present investigation a constant curvature approximation is introduced in the dipping sequence as well as in the find joint configuration. This reduces the problem to one of a geometrical nature only. The results of the model are presented in dimensionless form, compared with the exact theoretical results for a horizontal conveyor, and compared with data from actual production joints. The fundamental concept upon which the model is based may also be extended to through-hole and leaded surface-mount components.