The Effect of Silane Coupling Agent on Viscosity and Mechanical Properties of TIM1

Thermal interface materials (TIM1) are the key materials for thermal management in IC packages. There is an ongoing trend towards lower viscosity and excellent mechanical properties. Low viscosity is often required to make the materials fully fill the gaps under low installation pressure. Excellent mechanical properties, such as tensile property and adhesion, can relieve the inner stress caused by the Coefficient of thermal expansion mismatch. The silane coupling agent (SCA) plays a vital role as a molecular bridge to connect the polymer and inorganic fillers. In this work, we firstly prepared silicon composites at 90wt% of aluminum/zinc oxide with a model SCA (n-octyltriethoxysilane). We systematically studied the influence of the dosage of SCA on the viscosity and mechanical properties of TIM1. The viscosity decreased obviously from 383 to 277 Pa s@5/s due to the enhanced compatibility and dilution effect. The elongation gradually increased from 85 % to 290 % with the increase SCA dosage. While the relevant tensile strength showed a gradual decrease trend. Influenced by wettability and TIM1 bulk strength, the adhesion increased from 127 to 146 KPa, then decreased to 77 KPa. This study points out the content of SCA has an optimal proportion to balance the viscosity and mechanical properties of TIM1.