This Small Business Innovative Research (SBIR) Phase I project is aimed at demonstrating the feasibility of an electronic packaging technology for manufacturing power electronics modules that are critical for electrical energy processing in a wide range of systems, such as hybrid or electric vehicles, renewable energy generators, and the power grid. Recent advances in power semiconductor devices and substrate technology require packaging schemes which optimize the performance of each component for further increases in reliability, density, and high-temperature performance. The best route for meeting this need is to explore three dimensional package architectures which have previously been a barrier for manufacturing using solder techniques. This project will build on the commercialization success of a nanomaterial technology for device interconnection, to develop and implement an innovative three dimensional package architecture which can be force cooled equally well from both sides. The nanomaterial, which already boasts significant increases in thermal and electrical conductivity, is known to provide high reliability and high temperature joints for device interconnection. In addition, processing requirements can be tailored to significantly simplify fabrication of architectures which are difficult to create using existing solder and epoxy connection schemes. Utilizing the processing benefits of the nanomaterial die attachment, the specific technical objectives are: (1) development of a manufacturable process with the nanomaterial for fabricating the planar power modules; (2) testing of the modules under applied continuous current; and (3) evaluation of the module reliability under temperature/power cycling tests and (4) characterization of failure mechanisms. The double-side cooled planar power module technology enabled by the nanomaterial would lead to a highly competitive product in the market place.
The broader impact/commercial potential of this project would strengthen United States? manufacturing base in the field of power electronics. Power electronics modules are the central processing units for electrical energy conversion and are crucial to the nation?s economy and security. Energy applications, specifically those that provide independence from petroleum, require more efficient conversion of electrical power, and demand for reliability and sustainability of the nation?s power infrastructure requires an increasingly greater number of electrical conversions. Currently, the market of power electronics modules is dominated by products made in Europe and Asia. Successful commercialization of the technology developed in this project would usher in a competitive US manufacturer of power modules to the growing power electronics market. The success would further strengthen commercialization effort of the nanomaterial product developed under a NSF STTR program and directly translate to economic growth for Southwest Virginia. Success of this program would also serve as a good educational and business model for transferring fundamental knowledge developed under NSF?s support into the commercial world. It would present students an ideal case study to experience technological and economical impacts of their research activities.
The goal of this Small-Business Innovative Research Phase I project, supported by the National Science Foundation, was to evaluate the feasibility of a novel power electronics module assembly technology for power conversion applications in industries such as aerospace, automotive, and military. High performance and high reliability demands of these applications are pushing the state-of-the-art power module assembly technologies to their limits. Innovative assembly technologies that can support power device operation at high temperatures and dissipate heat from both sides of the devices are needed to advance the applications. The proposed assembly technology leverages a patented nanomaterial developed by NBE Technologies, LLC to replace low-temperature solder materials widely used in today’s power modules. It also embodies a low-profile, planar construction that joins the devices between two heat-sinking plates for effective heat extraction from both sides of the devices. To relieve thermo-mechanical stresses on the devices from mismatched coefficients of thermal expansion, we designed a compliance layer at the device to heat-sink interface and engineered it to be compatible with NBE’s nanomaterial processing. This double-side cooled, planar packaging technology, termed PowERazor, was successfully demonstrated with the development of its manufacturing processes and measurements of the thermal and electrical properties of the power modules. The manufacturing processes included flexibility to insure each power module possessed the optimal thermal as well as electrical performance metrics. The module testing results show high-temperature functionality up to 250oC and significantly better heat transfer property due to both increased dissipation surface area and flexibility in forced cooling scenarios.
