A rapid increase in the power of microelectronic devices, along with a reduction in their size, leads to a rapid growth in the density of dissipated heat flows. As a result, thermal management becomes a crucial factor for maintaining the stable uninterrupted operation of microelectronic devices. Stricter requirements for thermal interface materials (TIMs) make it necessary to optimize their production technology. A solution-based technology for obtaining grease with enhanced thermophysical properties is proposed. It has been shown that heat treatment of a mechanical mixture of aluminum nitride (AlN) and graphite (C) (1:1 by weight) in a vacuum at temperatures of 250–350 °C makes it possible to clean the surface of the particles from moisture and organic impurities, which leads to an increase in the thermal conductivity of the materials obtained. It was revealed that the best solvent at the processing stage is AlN:C silane is ethanol due to the high chemical similarity with silane surfactant. In contrast, when introducing particles into polydimethylsiloxane (PDMS), the highest thermal conductivity results were achieved with acetone as a solvent. The use of ultrasonic treatment of the filler, when introduced into the polymer matrix, was considered. It was shown that the optimal duration is 10 to 15 min, depending on the surfactant. The resulting thermal pastes have sufficient thermal conductivity (up to 2.25 W/(m·K)) and high thermal stability up to the flash point of PDMS (340 °C).