Super heat dissipation material: Diamond wafers

According to statistics, power device failures caused by heat concentration account for 55% of the total failure rate. The selection of heat dissipation materials for products has a crucial impact on the safety and stability of the instrument. Diamond is currently one of the materials with the highest known thermal conductivity. Its thermal conductivity is as high as 2000W/m · K, which is more than five times that of copper and eight times that of aluminum. Therefore, diamond wafers can more effectively transfer heat from the heat source to the radiator, greatly improving the heat dissipation speed.

1. Single crystal diamond material

Single crystal diamond has the highest thermal conductivity in the diamond material system, as it is a typical covalent bond crystal with weak lattice anharmonic vibration, long average free path of phonons, and fast transmission speed, resulting in extremely high thermal conductivity.

The use of single crystal diamond substrate epitaxial devices can significantly improve heat dissipation capacity. For example, using single crystal diamond heteroepitaxial single crystal GaN can significantly reduce device thermal resistance compared to traditional SiC substrates due to the excellent thermal conductivity of diamond. At the same time, the surface roughness is low and the optical performance is good, which can improve the performance of epitaxial GaN devices.

2. Polycrystalline diamond materials

At present, various technical forms of using diamond as a heat sink or substrate for power devices have been reported.Due to bonding technology being a more flexible parallel process, it is more attractive for heat dissipation in high-power semiconductor devices.

At present, room temperature bonding between polycrystalline diamond and Si, GaN, Ga2O3, etc. has been achieved through surface activated bonding (SAB) technology, greatly reducing the thermal expansion mismatch between the device and diamond. The interconnection in various electronic components and the generation of size robust junctions in laser equipment or thermal management in high-power devices have broad application prospects.

3. Nano diamond materials

The use of nano diamond film materials for heat dissipation is generally a passivation layer for high heat flux devices, while traditional devices generally use silicon nitride as the passivation layer to prevent external environmental fluctuations from affecting the functional layer. However, the thermal conductivity is extremely low. If diamond materials are used to replace the traditional passivation layer, uniform heating can be carried out on the device surface, adding a thermal conductivity path to the device and improving the surface temperature uniformity performance of the device.

CSMH has an international first-class level of diamond preparation, with the surface roughness of diamond wafers Ra<1nm. The thermal conductivity of diamond heat sinks can reach 1000-2200W/m · K. Its core products include diamond heat sinks, diamond wafers, diamond based gallium nitride epitaxial wafers, diamond based aluminum nitride films, etc., fundamentally solving the heat dissipation problems that restrict the application and development of high-power devices, microwave radio frequency, power electronics, optoelectronics and other technologies.