Package Dependency Investigation on Short Circuit Capability of SiC MOSFETs under Type 1 Condition

Inhalt:
This paper discusses the effects of package technology on the short circuit (SC) behavior of 1.2 kV Silicon Carbide (SiC) MOSFETs operating under defined conditions. The effect of three package types (TO247-3, TO247-4, and TO263-7) on short circuit capabilities are analyzed. The study focuses on the effect of key circuit-level parameters, including drain-source voltage (Vds), gate-source voltage (Vgs), external gate resistance (Rg), threshold voltage (Vth), and on-state resistance (Rdson) during Type 1 SC fault. Initial results shows that Vds and Vgs have a significant impact on short circuit withstand time (SCWT) compared to changes in Vth and Rg. Following the parameter analysis, the study shifts to evaluate the influence of packages under defined electrical conditions, with an experimental setup that isolates parasitic effects on providing clear insights into package-level changes. Thermally similar designs with various source pin layouts were compared in this study using the TO247-3 and TO247-4 packages, and the TO263-7 package was used to evaluate the effects of an alternative thermal behavior with a source layout similar to TO247-4. With this experimental setup, it is easier to assess whether the source pin design or thermal properties have a bigger impact. The results reveal that the inclusion of a Kelvin source pin and package inductance significantly affects SCWT, with the Kelvin source pin diminishing short circuit performance.