Interphase effect on the effective moisture diffusion in epoxy–SiO2 composites

Epoxy Mold Compounds (EMC) are used to protect integrated circuits (IC) from environmental influences, with one of these influences being moisture ingress, causing corrosion. To obtain the needed thermal and mechanical properties EMCs require a high loading (silica) fillers, introducing large amount interface. While silane coupling agents promote good binding, they have shown introduce an interphase volume that exhibits faster transport between epoxy SiO2 in glass fiber filled epoxy. In this work, we investigate if such is also introduced by filler particles EMC it diffusion coefficient composite. We compare uptake measurements performed dynamic vapor sorption (DVS) predictions effective medium theory, as well numerical simulations based on micro-CT scans our samples for model system containing different levels commercial two levels. From measured DVS data, observe coefficient, higher than predicted absence any both system. This suggests layer should be present.