Obtaining thermal resistance of mold compounds using a package structure model with a heat-generating test element group: Comparison of the thermal conductivity and glass transition temperature of epoxy mold compounds

Epoxy mold compounds (EMCs) with thermal conductivity of 0.8–4 W/m∙K and a glass transition temperature (Tg) of 150–270 °C were prepared using epoxy resins with various network structures and SiO2 and Al2O3 fillers. The test structure was fabricated using a heat-generating test element group (TEG) chip and an EMC in which the thermal conductivity and Tg varied. The TEG chip has two types of measurement pad: one for sensing the surface temperature and the other for heating the chip surface. The thermal resistance of the package structure model decreased from 14 °C/W to 4 °C/W from 0.8 to 4 W/m∙K, with the thermal conductivity of the mold compound having the same Tg. The thermal resistance of the package structure model decreased from 7.5 °C/W to 5.5 °C/W by increasing the Tg of the mold compound having the same thermal conductivity from 150 °C to 270 °C. Control over the thermal conductivity of the EMCs appeared to have a greater effect than the Tg on the thermal resistance of the package structure model using a TEG. The liquid EMC with a thermal conductivity of 4 W/m∙K provided the lowest thermal resistance (4 °C/W) among the EMCs examined.