It has been half of a century since the publication of the early reports about CVD diamond films in the world in the early 1970’s. As a multi-functional material with a vast combination of extraordinary electrical, mechanical, thermal, optical, acoustic, and electro-chemistry properties, the CVD diamond has wide applications potentially in the field of multidiscipline high technologies.
The advantage for using diamond film as the heat dissipating material is of course due to the extraordinary high thermal conductivity (20 W/cm·K at room temperature, almost 5 times to that of Cu), and the highly insulative property (resistivity as high as 1016 Ω.cm). This prompted a long list of potential applications waiting to be realized, from the heat sink (heat sink) of the high-power laser diode arrays and the packaging of the high-power electronic devices, to the thermal management of the high power electronic and the electron-optic systems.
An excellent example is the high-power electronic system in satellite, where the available space is extremely limited, and the heat dissipation is very difficult. Recently, high performance thermal grade freestanding diamond plates have been successfully used in the Chinese Big Dipper navigation satellites as the heat sink for the high-power space phased array antenna. The heat sinks were fabricated with the high-power DC Arc Plasma Jet by USTB. Miro-trenches were fabricated by laser cutting on the back side of the diamond plate to form the passages for the cooling fluid. Boarding test in the orbit showed that the cooling ability was as high as 500 W/cm2, which was the same as that of the ground test. Now, there are four Big Dipper navigation satellites with diamond heat sink cooling space phased array antenna currently functioning in space.
Diamond heat sinks have been successfully used in the Big Dipper navigation satellites. Thermal grade diamond film materials are now commercially available in the Chinese market. However, the market size is still not very big. There is an urgent need in the cheaper diamond heat sinks for the rapid development in the 5 G communication high power base station electronics, the high-power electronics and optoelectronics for civilian and the military uses.
DC Arc Plasma Jet is advantageous in the mass production of the thermal grade freestanding diamond wafers. However, it is capable for the production of different quality grade diamond materials from the cheaper tool grade to the expensive optical grade diamond wafers. The thermal conductivity of the thermal grade diamond material by DC Arc Plasma Jet overlaps with the tool grade at the low end (8-10 W/cm. K, light brown to yellowish) and the optical grade at the upper end (≥17 W/cm. K, light yellow to colorless). Therefore, the right choice of the proper thermal grade diamond materials will be an effective way to lower the cost. In one word, the need for the diamond heat sinks is urgent and is a rigid demanding.
CSMH offers diamond heat sinks in a variety of thermal conductivity grades, with the highest grade having a thermal conductivity of up to 2200 W/ (m · K). Diamond heat sink with combined electrodeposition have been proven by customers to effectively dissipate heat from heating components, thereby reducing the risk of overheating and extending the service life of electronic devices. CSMH also has diamond wafer, single crystal diamond and so on.