Heat Spreader for High Power Amplifier Device Material Stack-up

We propose to develop a novel cost-effective process to produce carbon nanotube enhanced copper nanocomposites with ultra high thermal conductivity. The process can also tailor the coefficient of thermal expansion (CTE) to match those of all semiconductors. This new nanocomposite is well suited for heat spreading directly under high power RF devices to avoid large temperature gradients. The technique can be also used to produce flow structures such as microchannels for the thermal management of high-voltage GaAs and other WBG power amplifiers that operate at very high power densities. In Phase I, we will demonstrate that the thermal conductivity of the nanocomposite can be more than twice as high as that of copper. While the carbon nanotubes are aligned in the fabrication process, a woven structure can be designed so that the nanocomposite can achieve effective heat spreading in all directions. We will also demonstrate that the CTE of the nanocomposite can be controlled to match those of semiconductors, thus significantly improving the reliability of the radar T/R modules. The effectiveness of this new material as a heat spreader will be demonstrated experimentally. The goal of the overall effort (Phase I and beyond) is to produce a thermal management subsystem that can enhance performance of T/R modules while lowering their production cost.