A lumped-parameter mathematical model has been developed for the laser soldering process and validated experimentally by measuring the temperature of solder preforms placed on a lead on a printed circuit board when heated with laser. This model results in four first-ordered nonlinear differential equations, which can be solved with MATLAB.
Further, a comparison has been made between diode laser, and Soft Beam (xenon-arc white light) soldering with respect to the solder joint quality, cycle time and input optical energy requirements. In addition, scanning electron microscopic studies have been done to compare the microstructure of the solder and the formation of intermetallics, when the solder is melted with laser, Soft Beam and a conventional soldering iron. It is found that the diode laser soldered joint has a thinner intermetallic and finer grain size resulting in a higher mechanical strength.