Chemo-thermo-viscoelastic behavior of underfill materials during curing process

The mechanical properties of thermosetting underfill materials strongly depend on the curing process itself and, hence, it is important to understand the effects of temperature distributions and degree of cure on the mechanical behavior of the underfill. Moreover, the understanding of rheological changes during the curing process is essential for the manufacturing process optimization. In this paper, the chemo-thermo-rheological behavior of the underfill material during the cure process is presented. These experiments reveal the material properties dependent on temperature and degree of cure. Cure kinetics for underfill materials are determined. In addition, constitutive relations of underfill materials during curing process are presented using mechanical models with time, temperature and cure dependent parameters.