Consideration of parameter scattering in thermo-mechanical characterization of advanced packages

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