A heuristic force-height equation for molten axisymmetric solder joints

Abstract

A heuristic equation is developed which relates the height of a molten joint to its surface tension, geometric constraints, and the applied force. In its present state, the equation is valid only for heights varying up to 10% from the zero-load shape, although a method is suggested to extend this range. The equation agrees well with published data derived from an exact solution, and with the data from a small laboratory experiment. The equation is intended as a practical tool for packaging engineers and designers who do not have access to the software needed to obtain the exact solution.<>