A Numerical Model for Joule heating in Sn Solder Balls of Two Different Sizes

For Pb-free solder joints of different volumes undergoing current stressing, numerical simulations can provide useful insight into the aspects of materials design and reliability. In this study, finite element method based computer simulation is performed to calculate the current density and temperature raise in tin solder balls of base radii of 100 and 1000 μm respectively. Under the application of fixed external potential difference of 0.0007 V, it has been found that the current density in smaller solder ball is about 10 times larger than that of bigger ball. Consequently, the absolute magnitude and rate of temperature increment is much larger in context of smaller ball. Incorporation of melting simulation and temperature dependent material properties are the targeted future works in this computational model.