Ultra-high thermal conductivity aluminum nitride composite sub-micron silica gel has good thermal conductivity, good electrical insulation, electrical insulation and a wide temperature (working temperature -60 ℃ - 200 ℃), low-consistency and good workability. Products have reached or exceeded imported products, as it can replace similar imported products which are widely used in electronic devices heat transfer medium, and enhance efficiency. Such as the CPU and radiator interstitial, high-power transistors, SCR components, diodes, slits in contact with the substrate at the heat transfer medium. Sub-micron ultra-high thermal conductivity aluminum nitride composite thermal paste is filled with IC or a transistor and the gap between the heat sink, increasing the contact area between them to achieve better heat dissipation effect