SBIR/STTR Phase I:Multimodal High-Conductivity Filler for Epoxy Molding Compounds

This Small Business Innovation Research (SBIR) Phase I Project will investigate the feasibility of incorporating diamond powder in epoxy molding compounds at high packing densities using optimized multi-modal distributions of diamond powder. The resulting thermalconductivities of these composite encapsulants are expected to be higher than 100 W/mK. Selection of semiconductor molding compounds that exhibit high thermal conductivity are crucial in dissipating heat generated by high-power electronic components, particularly as feature sizes of future chips decrease in size. Most epoxy molding compounds used to encapsulate semiconductors contain fused silica (55-70% by volume) to maintain a compatible thermal expansion coefficient and impart moisture resistance. However, the resulting thermal conductivities of the composite compounds are very low (<3 W/mK). By loading commercial molding epoxies with optimized diamond powder distributions, diamond volume fractions above 65% may be obtained in the epoxy molding liquid with a viscosity compatible with commercial molding processes. The diamond/epoxy molding compound will serve as a upper-limit benchmark material for thermal conductivity and will be used in high-performance microelectronic packaging applications where heat dissipation is critical.