Cure induced Warpage of micro-electronics: comparison with experiments

Warpage of micro-electronics caused by the curing process and thermal cycling is of major importance in electronic packaging. Industry is availed by good methods to be able to predict warpage accurately. The main difficulty for prediction of warpage is caused by the complicated material behavior of molding compound. It turns out that the mechanical behavior of molding compound is dependent on time, temperature and degree of conversion. Since molding compound is available in large variabilities, for each type the model parameters should be established experimentally. In our group an efficient method is developed for experimentally determining the model parameters [1, 2, 3]. In this approach, different experimental results have to be combined in order to achieve the final material model. Since this material model is not standard, user-subroutines are used for implementation in finite element software (ABAQUS). In this paper we present validation experiments which are done in order to verify the material model. A TDM (Topography and Deformation Device) is used to measure the curvature of a mold-map at different temperatures. Good agreement between experiment and simulations results is achieved.