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International audience; Silver sintering is used to bond five components together, in order to form a piezoelectric sensor. A description is provided of the preparation of these components, and of the manufacturing steps, which are carried out at a low temperature (280 °C). The resulting sensor assemblies are then characterized: cross-sectional views show that the silver layer has a very dense structure , with less than 1 % porosity, although further focused-ion beam investigations show that this porosity is closer to 15 %. The shear strength is approximately 30 MPa. The Young's modulus of the silver bondline is measured using nanoindentation, and is found to be comparable with that of bulk silver (56.6 GPa). Finally, a silver-sintered sensor is compared with a sensor bonded using conventional techniques, showing that an improvement in sensitivity by a factor of more than 3 is achieved.

This paper reports the design, fabrication and experimental performance of a 2kW, 20kHz, High Temperature, three-phase, all-SiC JFET Voltage Source Inverter (VSI). The inverter includes a specific JFET driver and a DC-link capacitor. All these elements have been validated over a wide temperature range, between 25°C and 200°C. The power device used, a 1200V, 15A, JFET from SiCED has been characterized up to 200°C. An innovative reliable protection circuit for normally-on devices is also presented and validated.

International audience; The power devices needed to build a high-temperature converter (inductors, capacitors and active devices) have been stored at 200°C for up to 1000 hrs. Their characteristics have been monitored. Capacitors and magnetic materials from various manufacturers and technologies are tested, as well as silicon-carbide diodes. It is shown that by carefully choosing the components, it is possible to build a reliable power converter operating at high temperature.

12 pages; International audience; This paper deals with the issue of electromagnetic interference (EMI) in SiC-JFET inverter power modules, and proposes a solution to limit conducted emissions at high frequencies. SiC-JFET inverters can achieve very fast switching, thereby reducing commutation losses, at the cost of a high level of EMI. In order to limit conducted EMI emissions, it is proposed to integrate small-value common mode (CM) capacitors, directly into the power module. High frequency noise, which is usually difficult to filter, is then contained within the module, thus keeping it far from the external network. This approach is in line with the current trend towards the integration of various functions (such as protection, sensors or drivers) around power devices in modern power modules. To demonstrate this concept, the resulting CM noise was investigated, and compared with a standard configuration. Simulations were used to design the integrated capacitors, and measurements were carried out on an experimental SiC-JFET half-bridge structure. A significant reduction was achieved in the experimentally observed CM conducted emissions, with a very minor influence on the switching waveforms, losses and overall size of the system. The benefits and limitations of this design are discussed, for the case of mid-power range inverters for aircraft applications.

International audience; SiC JFETs are experimentally tested to verify their robustness against Lightning induced strokes. The experimental set-up is fully described. A lightning surge generator is built and a SiC JFET is stressed. The full thermal response of the SiC JFET internal temperature is obtained from a specific temperature estimation technique at different time steps during the surge test. This short time thermal response is compared and validated by a conventional 1-D thermal model. This work shows that for a moderate lightning stroke, according to standards [1], the JFET temperature rise is less than 60°C, which is acceptable in most circumstances.

International audience; SiC-JFET based inverters can achieve very fast switching, hence reducing the commutation losses, at the cost of increased Electro-Magnetic Interferences (EMI). To keep the EMI conducted emissions within reasonable limits, we propose to integrate some small-values capacitors directly into the power module. Common Mode (CM) is investigated and compared with a standard configuration. The high frequency noise, which is usually difficult to filter, is contained in a close loop with the switching source, and far from the network. To demonstrate this concept, simulations are used as well as experiments on a SiC-JFET half-bridge structure. Benefits and limitations are investigated in the case of mid-power range inverters for aircraft applications.

International audience; In this paper, a high temperature EMI input filter for a SiC JFET inverter is designed and tested in operating conditions at 200°C. Inverter EMI issues, design procedure and characterizations of selected components are presented in details. The feasibility based on industrially available materials and components is demonstrated with a low temperature dependence of EMI Spectrum.

In this paper, the fabrication of LTCC capacitor based on a high dielectric-constant LTCC capacitor paste is introduced. A simple analysis is made for failure modes in fabrication process. Small signal and high voltage performance is tested with a single-layer ceramic capacitor sample to prove the possibility to use it in high power converters

EMI filters are mainly made up of passive components including capacitors and inductors. These passive components can be a significant portion of the total converter system volume. Integration techniques can be used to improve space utilization and reduce the total system volume. This paper gave a comparison on existing passive integration technologies, and then developed an integrated EMI for 2 kW DC-fed 3-phase motor drive system. Design procedures are established and FEA simulation is used in verifying the design. Both small signal and in circuit EMI noise test were performed to verify the filter design.