Effect of Al₂O₃ gradation on rheological behavior and thermomechanical properties of epoxy molding Compounds

With the development of electronic products towards high-density integration, high performance, and multi-functionality, epoxy molding compound (EMC) puts forward higher requirements for its thermomechanical properties. Combining excellent comprehensive performance and good processing compatibility is a complex problem in EMC development. Therefore, this paper adopts spherical Al2O3 with particle sizes of 1 μm, 5 μm, 10 μm, and 20 μm to design the filler gradation scheme and study the effect of Al 2 O 3 gradation on the viscosity, thermal conductivity, thermal expansion coefficient, storage modulus, and fracture toughness parameters of epoxy composites. The results show that a good filler gradation design can enhance the desired EMC performance. The best performance of epoxy composites was obtained with the mass ratio of Al 2 O 3 of 1:5:10:20 (μm) = 1:1:3:5. The maximum improvement values of room temperature viscosity, thermal conductivity, thermal expansion coefficient, modulus of elasticity, and K Ic were 100.91%, 14.49%, 28.16%, 8.75%, and 34.80%, respectively, compared with other gradation systems. The results of this study can provide guidance and suggestions for developing a high-performance EMC and optimizing the filler grading scheme.