Consideration of Parameter Scattering in Thermo-Mechanical Characterization of Advanced Packages

Much progress has been made in the simulation and verification of the thermo-mechancial behavior of plastic packages. On the other hand, until now there is a lack in the consideration of the scatter or uncertanity, respectively, of certain characteristics. A comparatively large scatter of local material properties or random geometrical imperfections can often be observed within the material compounds of electronic packages. The partial randomness of certain input parameters creates uncertainties in the finite element determination of mechanical quantities which are provided for thermo-mechanical reliability optimization and life time prediction. In the following the STOFEM stochastic finite element approach based on perturbation theory is applied as a part of the finite element simulation. It is used to find out some additional effects arising from uncertanities in the modeling, slightly varying parameter or probabilistic influences, respectively. In a second part of the paper, another approach to the consideration of ramdom variations is discussed. It is based on the randomization of initially deterministic relations.