Packaging 3D pour MOSFET en carbure de silicium

International audienceLe développement d'un packaging dédié aux transistors à grand gap (SiC et GaN) est un point clef pour tirer pleinement profit de leurs caractéristiques remarquables. Un packaging en trois dimensions, basé sur un procédé de fabrication des circuits imprimés, est présenté dans cet article. Une cellule de commutation à base de MOSFET SiC est développé avec une inductance parasite de seulement 0.25nH. De plus, les interconnexions électriques du module sont réalisées sans brasures ni fil de bonding. Un module 3D est fabriqué puis validé expérimentalement. Des caractérisations électriques statiques et dynamiques sont réalisées et valident électriquement le concept « Power Chip On Chip » avec un procédé de fabrication de circuit imprimé

Thermal Considerations of a Power Converter with Components Embedded in Printed Circuit Boards

International audiencePrinted-Circuit-Board (PCB) technology is attractive for power electronic systems as it offers a low manufacturing cost for mass production. Integration technologies such as device embedding have been developed to take advantage of the inter-layer space in multi-layer PCBs and to increase the performances (Electrical, Thermal). However, the PCB technology offers limited power dissipation due to the low thermal conductivity (≈0.3 W/(m·K)) of its composite substrate. In this paper, we consider PCB embedding for a 3.3 kW AC/DC bidirectional converter. We describe the integration of not only the power dies, but also the gate drive circuits and the power inductor, with a special focus on the thermal management. The manufacturing processes of the boards are presented. Two thermal models based on finite elements (FE) of this converter stage are introduced. The accuracy of these models is validated against experiments. The results show that a simplified FE model offers satisfying accuracy and fast simulation, even considering the relatively complex structure and layout of the PCBs

Evaluation of the PCB-embedding technology for a 3.3 kW converter

International audienceThis paper presents a converter fully made using PCB embedding technology (including the semiconductor devices , but also their gate driver circuits as well as the passive components). This converter is rated at a high-power (3.3 kW) considering the PCB technology. Here, the focus is given to the experimental validation of the embedding process, with the characterization of many of the embedded devices (SiC MOS-FETs, diodes, capacitors). These results show that most of the components were unaffected by the process, with the noticeable exception of the large inductors which exhibit variations in the inductance values as well as a large ac resistance. Finally, the converter is successfully assembled an tested at low power

Application of Fluctuating Asymmetry Values in <i>Pelophylax ridibundus</i> (Amphibia: Anura: Ranidae) Meristic Traits as a Method for Assessing Environmental Quality of Areas with Different Degrees of Urbanization

In this paper, we assess the environmental impact of urbanization in three freshwater biotopes, using the levels of fluctuating asymmetry (FA) in 10 meristic morphological traits in the Marsh Frog (Pelophylax ridibundus (Pallas, 1771)). Two of the studied biotopes are located in the boundaries of the city of Plovdiv (one in the central part, the other in a suburban residential area), and the third is located in the vicinity of the village of Orizare. Our working hypothesis is based on the assumption that urban and suburban sites are more severely affected by human activities than rural sites. However, according to our results, the population of P. ridibundus inhabiting Maritsa River in the central part of Plovdiv City, and that in the suburban zone, have found relatively good living conditions. Contrary to our expectations, the worst environmental conditions were observed in the rural zone, where anthropogenic stress related to intensive pastoral animal husbandry and crop farming was present. The absence of adult individuals in the rural site is also an indicator of unfavorable living conditions