QFN package isgetting rapid market acceptance becauseof itsexcellent thermal andelectrical performance anditsminiaturization andlowcost. However, thewarpageproblem caused bymolding process imposes agreat concern forthemanufacturing of theproducts. To investigate theeffect oftheEMC properties, package parameters andprocessing conditions onthewarpage, experimental approach andnumerical simulations wereconducted onPhilips business carrier HVQFNpackage. A series ofmolding experiments for QFNmatrix strips withthemodel-molding compounds wereperformed. Inthemolding experiments, different processing parameters, filler loading anddiethickness wereused. Thewarpage wasmeasured byacontact probe coordinate measuring system. Inthefinite simulations, a previously proposed cure-dependent constitutive model fortheencapsulating EMC wasapplied todescribe the behavior ofthematerial during thecuring process. The results showthat bothofthefiller percentage andthedie thickness hasasignificant effect onthefinal warpage level.