HYPOTHESIS was a focused RTD project that investigated the feasibility of a High Temperature Intelligent High Integrated Power Electronics Module for aeronautic applications based on fast switching semiconductors, most probably using Silicon Carbide technology for the first generation power modules. The recent release of 1200V SiC power transistors (MOSFET’s, JFET’s…) with strongly improved switching behaviour provided an interesting opportunity for the development of Power Electronic Modules that are dissipating much less, can operate at higher frequencies and at temperatures up to 250ºC, do not require forced cooling and therefore reduce weight and volume. In order to take full advantage of the high switching speed of SiC transistors, the gate driver has to be placed as close as possible and ultimately integrated in the same power package. The challenge is to combine the materials and the technologies for die attach, power substrates, interconnect, wire bonding and final assembly into one module that can operate at high power levels and high temperatures at the reliability levels required for aeronautics.
The HYPOTHESIS project took up this challenge based upon the experiences in integrated circuits for high temperature operation and on the results of recent state-of-the-art investigations. It investigated the feasibility of the technology for intelligent High Integrated Power Electric Modules that fulfil the requirements set forward in the call topic JTI-CS-2011-3-SGO-02-037 and that is based on the requirements for the More and All Electric Aircraft.
After a thorough analysis of the requirements and of the available and affordable technologies, an experimental module was designed, manufactured and validated for performance and reliability. The design and technology recommendations that resulted from this investigation will contribute to the next generation of intelligent HIPEMs suited for the next generation of All Electric Aircrafts.
A 3-Phase 1200V/150A SiC MOSFET Intelligent Power Module (IPM), including both the power devices and the isolated gate driver, was specified, designed, manufactured and tested to meet the requirements of the More Electrical Aircraft in developing smaller and lighter power converters (see picture in Figure 1 of Annex 1). This power module was based on advanced materials to enable high temperature operation and to achieve the highest reliability.