Thermal Management

The continuous miniaturization trend, increasing operating speeds and rising power levels pose major challenges to the thermal management of discrete and integrated electronics. The ability to dissipate heat not only limits output levels of many high power microelectronic and optoelectronic applications, such as radar and other radio-frequency (RF) devices, power semiconductors, laser diodes and light-emitting diodes (LEDs). It also controls frequency of microprocessor units (MPUs). In addition, thermal management affects device performance and reliability. Nearly 60% of the failures are temperature-induced and for every 10 °C rise in operating temperature the failure rate nearly doubles ^[1]. Therefore, it is particularly important to find excellent thermal management materials. Diamond is not only the hardest material in the world, but high-quality diamond is also one of the highest known thermal conductivity materials in the world. For example, polycrystalline diamond made by chemical vapour deposition (CVD) has room temperature thermal conductivities as high as 2200 W/m·K. In addition, diamond also has high resistivity, low dielectric constant, low thermal expansion and other characteristics. Therefore, diamond has gradually become an ideal thermal management material in the electronics industry, which can meet the requirements of high-density and highly integrated assembly development in the rapidly developing electronics industry.

Applications

At present, there are many examples of applications of diamond in thermal management. Here are some typical applications.

• Application of diamond in GaN high electron mobility transistor (HEMT): HEMT devices made of GaN materials can provide more than 10 times the power density of existing Si technology, and are widely used in radar, electronic warfare systems, cellular base stations, satellites and others. However, this huge power density will generate a lot of heat, which will seriously affect the service life, reliability and performance of the device, and even cause the chip to burn out. Using CVD diamond with high thermal conductivity as thermal substrate for GaN HEMT is the most promising thermal management method at present. There are two main approaches to GaN HEMT technology based on CVD diamond substrate: One is the deposition growth process, which is to grow diamond material on the GaN device or epitaxial growth GaN device layer on the diamond to complete the integration of thermal diffusion layer; The other is the bonding process, which is to bond the CVD diamond substrate with the GaN device layer at low temperature or even room temperature to reduce the interface thermal resistance of the device. Both approaches have been studied extensively over the past two years, and it has been confirmed that CVD diamond is an important thermal management means to further improve the GaN HEMT devices, and has great research potential and application value.

• Application of diamond in LED: The advent of high power LEDs revolutionized lighting applications. However, even though the efficiency of these devices is considerably high, they also suffer from heating problems. As with other semiconductor devices, the junction temperature has a huge impact in the lifetime of an LED and should be kept as low as possible. Different approaches can be used to improve the dissipation of this heat to the environment, and one of the most effective methods is the use of CVD diamond plates to improve the extraction of heat from the back of the LED case ^[1].
• Application of diamond in perovskite nanoplatelet laser: Perovskite has excellent photoelectric properties and is a promising laser gain medium. However, due to the poor thermal conductivity of perovskite and other reasons, the laser device has a significant temperature rise. Therefore, it is necessary to introduce effective thermal management measures in the structural design of laser devices. Using high thermal conductivity substrate to improve the heat dissipation of perovskite laser devices is the most important thermal management method. It has been reported that using diamond as the high thermal conductivity substrate and inserting SiO₂ layer between the perovskite nanoplatelet and diamond to reduce the light leakageand contact thermal resistance of diamond can achieve excellent heat dissipation effect of perovskite nanoplatelet laser. Its heat dissipation effect is better than other currently used thermal management materials such as sapphire, hexagonal boron nitride and silicon.

Meet Alfa Chemistry

At Alfa Chemistry, we are committed to providing the highest quality superhard materials of diamond and CBN to various fields. Today, with our in-house expertise in diamond, we are also committed to the development of diamond thermal management materials to meet the needs of thermal management field. We have successfully developed CVD diamond which can help you reduce thermal management bottlenecks and achieve lower operating temperatures, higher performance, and longer system life in a variety of electronic applications. With our advanced products and unparalleled expertise, we are confident that we can provide superior diamond products solution that meet your thermal management needs and help you gain a competitive advantage in the market with higher product performance and lower production costs to achieve their goals.