The thermal conductivity of diamond reaches 2000W/(m·K), which is lower than that of graphene, but much higher than that of other materials. Graphene conducts electricity, while diamond does not conduct electricity, and is an insulating material, so diamond is more suitable for insulating applications.

Diamond has unique thermophysical properties (ultra-high thermal conductivity and semiconductor chip-matched expansion coefficient), making it the preferred heat-dissipating substrate material. However, it is not easy to prepare a single diamond into a block, and the hardness of the diamond is extremely high, and the diamond block material is difficult to process. Therefore, the practical application will be applied in the heat dissipation substrate material in the form of "diamond particle reinforced metal matrix composite material" or "CVD diamond/metal matrix composite material". Common metal matrix materials mainly include Al, Cu and Ag.

According to the research, it is found that after 0.1% of the boron nitride content in the polyhexamethylene adipamide (PA66) type thermal composite material is replaced with nano-diamond, the thermal conductivity of the material will be increased by about 25%. By further improving the properties of nano-diamonds and polymers, Carbodeon in Finland not only maintains the original thermal conductivity of the material, but also reduces the consumption of nano-diamonds by as much as 70% during the production process, greatly reducing production costs.
This new thermal composite material was developed by the Finnish VTT Technology Research Center and tested and verified by the German company 3M.

For materials with higher thermal conductivity requirements, the thermal conductivity can be greatly improved and improved by filling 1.5% of nanodiamonds per 20% of the thermally conductive filler.
The improved nano-diamond thermally conductive filler has no effect on the electrical insulation properties and other properties of the material, and does not cause tool wear, and is widely used in electronics, LED equipment and other fields.