SBIR Phase I: Low-Cost High Performance Cold Plate for Power Electronics Thermal Management

This Small Business Innovation Research (SBIR) Phase I project is focused on the development of a novel, low-cost cold plate for power module thermal management. This cold plate is enabled by a unique integrated package and heat sink assembly technology. The target application for the integrated package and heat sink assembly is high-temperature silicon carbide (SiC) power modules. SiC power modules offer significant improvements over conventional silicon power modules to include up to a 10 fold increase in power density, a 10 fold higher breakdown voltage and 90% lower switching losses. Currently, packaging technology to support SiC power module operation at temperatures of 250 oC and higher does not exist. The proposed integrated package and heat sink assembly is comprised of a ceramic-graphite-copper substrate joined to a unique, low-cost highly effective compact heat exchange surface. This integrated assembly provides for electrical isolation of the power module?s electronic components and circuitry, and minimizes the thermal resistance between the SiC devices and the heat sink coolant. Further, the assembly provides for the minimization of the coefficient of thermal expansion (CTE) mismatch between the different material layers of the assembly in order to minimize thermal stresses resulting from cyclic power and temperature operation ? key to achieving a reliable product with a long life. The primary research objectives of this project are the development of a low-cost unique integrated package and heat sink assembly and the establishment of the fabrication processes required to support its manufacture. There is a critical need for advanced packaging and active cooling solutions capable of meeting the thermal management requirements of emerging SiC power module applications which include: (1) hybrid electric vehicle (HEV) power inverters and converters; (2) power converters for renewable energy systems (e.g., solar arrays, wind generators); and (3) power supplies for a wide variety of electronic systems (DC power supplies and inverters). The broader impact/commercial potential of this project is the development of technology that will enable lower cost SiC power modules. Advances in semiconductor technology have led to smaller devices operating at higher power and the trend toward higher power semiconductor devices is forecast to continue. This trend is driving the demand for packaging materials that are closely matched to the CTE of semiconductor devices while lowering package overall thermal resistance. The proposed project will develop a cold plate based upon the integration of unique package and heat sink technologies for use in power modules. This integrated package and heat sink will minimize device/package CTE mismatch while reducing module overall thermal resistance by 60% to 70% compared to current packaging technology. This technology will enable power modules with higher packaging density and improved reliability and life. These improvements will lead directly to a power module cost reduction of 30% to 40% and will be key to driving the demand for SiC power module technology. The project research will produce the key knowledge required to enable the design and low-cost manufacture of reliable, highly effective integrated package and heat sink products for use in a range of power electronic systems. The target application for the technology is a SiC power module for use in an HEV application. This technology development will benefit a range of end user to include consumers and businesses. Further, considering the broad range of power module applications, the technology will benefit a spectrum of commercial, industrial, and military high power electronic systems end users. The annual commercial product sales based upon the technology is estimated to grow to ~$150 million over a 10 year time horizon. Finally, the adoption and wide-spread use of the package and heat sink technology will enable electronic systems based upon more efficient higher power semiconductor materials (e.g., SiC, gallium nitride, etc.). This will provide benefit to society in the form of more efficient, longer life electronics; reduced energy consumption; and improved environmental quality.