In this work, the mechanical properties of encapsulation materials for photovoltaic modules have been studied. A finite element model has been developed to simulate the degradation of solder bonds within modules subjected to different environmental conditions. Various polymeric encapsulants are characterized using constitutive techniques and included in the model. It is shown that the degradation rates of the solder bonds are dependent on the behavior of the encapsulant and that some encapsulants may cause higher or lower degradation than others depending on the use-environment.