High temperature operation of SiC transistors
Résumé
The objective of this presentation is to give an overview of the issues and possibilities associated with the high temperature (>200 °C) operation of SiC devices. The introduction presents the advantages of wide-bandgap semiconductors in general (and SiC in particular) regarding high temperature. A short review of the transistor structures available (MOSFETs, JFETs, BJTs. . . ) serves as a basis for discussion regarding their suitability to high temperature operation.In the second part, we present data that shows that although SiC JFETs can operate continuously at more than 300 °C, they are sensitive to thermal runaway. Actual devices were mounted in a test set-up where thermal resistance and ambient temperature could be adjusted independently. Drain current was gradually increased until the devices reached thermal runaway condition. This confirms that SiC JFETs must be be supplied with a proper thermal management (in the order of 1-2 K/W junction to ambient). This highlights that high-temperature electronics is not a substitute to proper thermal management.Finally, we present a packaging solution that offers dual-side cooling capability but only uses high-temperature-rated materials (ceramics, silver sintering, parylene HT encapsulation. . . ). The mounting of auxiliary devices (gate drivers, decoupling capacitors) in close proximity to the SiC devices (and therefore in a hot area) is also discussed.
Domaines
ElectroniqueOrigine | Fichiers produits par l'(les) auteur(s) |
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