Effect of Filler Particle Size and Surface Functionalization on the Properties of Thermal Grease

Thermal conductive grease is widely used for the heat conduction and dissipation of electronic components such as power amplifiers, transistors, electronic tubes, CPUs, etc., thereby ensuring the stability of the electrical performance of electronic instruments and meters. Increasing the thermal conductivity content can effectively improve the thermal conductivity of oil, but it will deteriorate its filling performance. Here, we report a thermal grease with both thermal conductivity and filling ability, which is prepared from spherical aluminum and zinc oxide functionalized by silicone oil and decyl(trimethoxy)silane, and shows high thermal conductivity and low viscosity at the same time. Decyl(trimethoxy)silane effectively bridges filler and silicone resin to form samples, which allows more filler loading while ensuring proper viscosity. The addition of large particle fillers not only improves the thermal conductivity of thermal grease, but also reduces its viscosity. The prepared thermal grease has good thermal conductivity (5.4 W m ^-1 K ^-1 ) and low viscosity (~ 526.3 Pa s), indicating its enormous potential in electronic packaging applications.