NUMERICAL ANALYSIS OF TRANSIENT TEMPERATURE DISTRIBUTIONS DURING LASER SOLDERING

Fast laser soldering processes are very attractive for the production of miniaturized interconnections with high reliability as they allow solder joint quality assurance during soldering. In order to evaluate the solder joint quality temporal changes of the temperature distribution inside the solder joint due to melting of the solder and wetting of the component and the pad metallizations must be well understood. In this paper we present thermal simulations of fast laser soldering processes taking the essential changes of the solder geometry into account. Moreover, we use a new relation for the calculation of the moment of wetting in dependence of the interface temperature. With this model the influence of the wettability of the pad and the component metallization and of the position of the laser beam on the temperature distribution inside the solder joint are investigated.