Impact of underfill filler particles on reliability of flip chip interconnects

Parametric analytical studies are conducted to investigate whether the reliability of flip chip solder interconnects are affected by underfill inhomogeneities, such as settling of the filler particles. The property gradation caused by filler settling is modelled with a micromechanical formulation. The predicted property gradients are then utilized in a finite element simulation of the flip chip assembly, to assess the impact on solder interconnect reliability.