Preparation and Properties Study of One-Part Additive Curing Silicone Composites Applying in Advanced Packaging

In 2.5D/3D stacked advanced packaging, one-part additive curing silicone composites are widely employed to achieve structural bonding and efficient heat dissipation. In this study, a thermally conductive silicone adhesive was prepared using medium viscosity vinyl silicone oil, hydrogen containing silicone oil, and micron-sized alumina powder as the primary components. The results demonstrated that the adhesive exhibited excellent thermal and mechanical performance. Specifically, its thermal decomposition temperature exceeded 400 °C, the thermal conductivity reached over 1.80 W·m⁻¹·K⁻¹, and the thermal resistance was below 12.0 °C·cm²·W⁻¹. The shear strength exceeded 5.00 MPa. Furthermore, after exposure to uHAST for 384 h, 1,000 thermal cycles, and thermal aging for 1,000 h, the adhesive maintained stable thermal conductivity and mechanical properties. The thermal conductivity remained above 1.70 W·m⁻¹·K⁻¹, and the shear strength remained higher than 5.00 MPa. In addition, the tensile modulus was maintained below 100 MPa, and the coefficient of linear thermal expansion was less than 160 ppm·°C⁻¹. Overall, the comprehensive performance of the adhesive satisfies the reliability requirements for advanced packaging substrates and heat dissipation lid assemblies.