Modeling of the underfill flow process in the flip chip bonded pixel detectors

Modeling of the underfilling process of the flip chip bonded components has been studied. The size of the hybridized pixel detectors used in the flip chip bonding process varied up to 1 cm * 1.6 cm. An underfill was required to enhance the mechanical properties of the bonded component. An imidazole based epoxy resin was used as the underfill polymer. Computational methods were considered to be highly attractive in order to reduce failure in testing of limited number of available experimental samples. In addition, the computational methods permit rapid definition of suitable process parameters. The polymer was modeled as a non-Newtonian fluid, which agreed with the actual material properties. The modeling was also selected as simple as possible. The obtained values were replicated as close as possible during the actual dispensing of the underfill material. The viscosity of the underfill material was adjusted by heating. The modeled parameters were validated by positive results on the bonded components.