Abstract: A polymeric composition for making semiconductor device packaging includes at least one epoxy resin, at least one curing agent in an amount between 30 and 110 parts by weight per 100 parts by weight of the epoxy resin, at least one silica-based reinforcing filler in an amount between 300 and 2300 parts by weight per 100 parts of the epoxy resin, and at least one control agent for a rheology of the polymeric composition. The at least one control agent may be substantially free from polar groups and present in an amount between 0.1 and 50 parts by weight per 100 parts by weight of the epoxy resin. The invention also relates to a plastic packaging material for microelectronic applications which may be obtained from the above polymeric composition, and to a semiconductor electronic device including such packaging material.