Scientists at the Georgia Tech Research Institute (GTRI) are creating a solid composite material made of silver and diamond for cooling powerful defense microelectronic systems. The silver-diamond composite material has excellent thermal conductivity in contrast to other materials presently utilized for this purpose.
The project focuses on developing an ultra-thin silver-diamond thermal shim of less than or equal to 250 µ. The proportion of silver to diamond in the composite material can be customized to enable effective bonding of the shim with minimum stress of thermal expansion to the powerful broad-bandgap semiconductors designed for advanced phased-array radars.
Thermal shins are required to extract heat from powerful semiconductors and transmit it to heat dispersing products such as fans, heat pipes and fins. As the semiconductors function in constrained areas, the thermal shins should be developed from a material that is capable of packing high thermal conductivity into a small arrangement.
Diamond offers excellent thermal conductivity and silver enables suspension of diamond materials inside the composite material. Diamond particles offer 25% higher thermal conductivity than copper. Till date, experiments revealed that the silver-diamond composite material outperforms in thermal expansion and thermal conductivity.
Jason Nadler, a research engineer at GTRI and the head of the project, stated that temperature reduction from 285°C to 181°C was achieved by utilizing a material made of 50% diamond in a thermal shim thickness of 250 µ.
The scientists are close to achieving diamond proportions that can be up to 85% in a thermal shin thickness of less than 250 µ. These higher proportions of diamond are offering better outcomes in archetype investigation.
Nadler mentioned that the innovation holds potential promise in the microelectronics segment and at present no other material provides this blend of functionality and thinness. Thermal efficiency rating of diamond is 2,000 W/m K, while silver has 400 W/m K.