The development of Wide Bandgap Semiconductors such as GaN has enabled tremendous improvements in power amplifier performance such as operational frequency and output power. These device improvements have in turn enabled performance and capability improvements in the end applications such as EW systems and radar T/R modules. The advances in device technology have not come without their own set of limitations which must yet be overcome. One issue that plagues equipment designers is the need for improved thermal efficiency which is exacerbated by the continuing requirement for smaller equipment footprints combined with increased functionality. While the development of ceramic multi-layer technologies has allowed smaller footprints to be realized through embedded circuitry and denser packaging, the thermal conductivity of such packages has not kept pace with the device technology itself. With the increased power densities expected from newer device technologies, an improved and advanced multi-layer packaging technology is being developed which takes into account the substrate materials and processing, the heat spreader material and attachment method, the final package into which the modules are mounted, newer devices and attachment materials, and the manufacturing and assembly processes in order to yield a high performance, thermally efficient, cost effective packaging solution.
Benefit: The thermally efficient packaging technology developed under this effort will find immediate military opportunities within the majority of all current and future military radar programs and is not limited to just the U.S. Navy or other U.S. military forces, and multiple foreign sales opportunities will likely present themselves. Additionally, as the basic packaging approach matures and is verified, the techniques, processes, and architecture utilized can readily be adapted for use by any number of military and commercial applications such as power amplifiers used within electronic warfare equipment, communications equipment, other radar applications, and optical networks. By developing multiple techniques and processes to address the thermal issues of GaN devices as well as the cost of current T/R modules and PA packaging, individual pieces of the developed approach can be adapted to specific requirements as they arise. Not every technique or process developed for the project will be required by every application, thus an end-users application can have an optimal packaging solution designed to meet their specifications by using any or all of the various aspects of the project.
Keywords: Multi-layer Substrate, Phased array radar, T/R Module, power amplifier, LTCC, Thermally Efficient Packaging
