Invited Paper EM-ThA3
Materials and Process Needs for Power Electronic Integration

Thursday, October 18, 2007, 2:40 pm, Room 612

A typical switched-mode converter contains semiconductor, conductive, magnetic, dielectric, and thermal-management elements. The wide variations in materials and processes employed to make these components, the large dimensions, and the requirements for low losses have limited the chance for integration. *** The integration strategy pursued divides the power electronic converter into three building blocks: Active, Passive, and Filter Integrated Power Electronics Modules (AIPEM, PIPEM, and FIPEM). Electro-magneto-thermal structures are described for realization of the functionalities expected from the structures. Materials and processes have been identified to verify the operation of the integrated structures. While the entire converter cannot be integrated using current technologies, the equipment and process steps to fabricate the three types of IPEMs are similar. *** The AIPEM structure (e.g., an "embedded-power" module) contains the semiconductor devices, the associated ancillary functions (e.g., gate drives, sensing, and protection), and thermal management elements (e.g., heat spreader, heat sink, and micro-channel coolers). Interacting with the AIPEM to shape the conversion gain is the PIPEM (e.g., an integrated inductor/capacitor/transformer network) containing passive components designed to propagate energy at the switching frequency. The FIPEM (e.g., an integrated lossy transmission line for EMI filtering), on the other hand, contains passive components designed to attenuate at the switching frequency, or the frequencies beyond the useful power bandwidth. *** Semiconductor materials employed include silicon, silicon carbide, and gallium nitride. Nano-material technology has been developed for bonding and interconnects, and multiferroic nano-composites for passive integration. Other common metals, polymers, and ceramics are also used. *** Exemplified processes include "Metal Post Interconnected Parallel Plate Structure," "Flip Chip on Flex," "Dimple-Array Interconnect," and "Embedded Power." Sputtering, plating, etching, spin-coating, screen-printing, tape casting, sintering, and solder reflowing are typical process steps. New materials and processes are needed for high yield and reliable operations under wide ranges of temperature, fields, vibration, pressure, and other environmental conditions.