A new metal matrix composite material consisting of natural graphite particulates processed into a designed reinforcement architecture that, after pressure infiltration casting with molten Al alloy, results in materials with thermal conductivity (TC) controllable over a range of 600 to 750 W/mK and thermal expansion controllable over the range of 7 to 3 ppm/K. This material, with strategically located high TC z inserts is proposed as base plate heat sinks for advanced GaN based phased array radar systems. The material system will be fully characterized. FEA thermal models will be developed for a 4 by 4 channel prototype array which will be manufactured for attachment to T/R module emulators and evaluated by a prime contractor partner for thermal performance. The goal is to enable a two- to three-fold increase in power density in wide bandgap semiconductors and to manufacture radar arrays with greater than 100 channels within essentially a page sized format. The constituent materials are inexpensive. Hence, the proposed technology, at the proper manufacturing scale will provide materials with a cost per unit volume less than copper at 1.5 to 2 times the thermal performance and CTE matching to the T/R module.
Keywords: Metal Matrix Composites; Passive Thermal Management; High Thermal Conductivity; Heat Spreaders; Heat Sinks; Thermal Expansion Matching; Gan Mmics; Phased Array Radar
