Effect of mold compound thermal conductivity on IC package thermal performance

The authors discuss the effects of varying the thermal conductivity of epoxy molding compounds on the thermal behavior of plastic IC packages. Thermal conductivity values were estimated for various filler types (fused and crystalline silica, aluminum oxide, aluminum and boron nitride, silicon carbide, and diamond), sizes, and distribution. Values for the resulting composites were used in determining the effectiveness of the compound in dissipating heat away from the package. Finite-element simulation was also used to predict the thermal performance of three different surface mount configurations, namely, SOIC 8-L, 16-L wide, and 24-L wide. The combined effects of the thermally enhanced mold compounds and enhanced leadframe designs were investigated. Natural convection and forced convection heat transfer simulation determined the effectiveness of the high thermal conductivity encapsulants under different application conditions