Thermal Pyrolytic Graphite Embedded Copper Graphite and Aluminum Graphite Composites for Thermal Management of Phase Array Radar Systems

In Phase I, MMCC combined discontinuous graphite fiber preforms with ultra high thermal conductivity (1700 W/mK TPG) inserts and created hybrid composites with thermal expansion matching to GaAs, SiC and GaN semiconductors and thermal conductivities from 800 to 1200 W/mK. A conventional Cu MetGraf skin/encapsulant with high conductivity preforms oriented in the “Z” (through thickness) direction (TC= 672 W/mK) was used to rapidly remove heat from the device. The heat was then transported by the combined MetGraf/TPG™ package from the heat source to the water cooled rail. We demonstrated that, by using the hybridization concept, two interface materials and bonding agents can be eliminated, resulting in further performance increase and cost savings. The thermal conductance of base plates in advanced radar systems were increased by a factor of 3 to 6 over present systems. In Phase II, we will apply this concept to thermally model and prototype air cooled Al MetGraf/TPG LRUs for a radar systems manufacture. In addition, we will prototype and thermally model hermetic base plates of Cu MetGraf/TPG for a liquid cooled T/R module for a second radar systems manufacturer. Manufacturing technology will be optimized to produce working prototype units for each of our technology insertion partners.