研究目的

Designing an electronics package for gallium oxide devices that meets the combined target of minimal thermal resistance and improved reliability.

研究成果

Thermal and thermomechanical FEA predicted the combination of AlSiC and Si3N4 to be the most beneficial for substrate-attach reliability. The CTE of AlSiC is highly compatible with that of DBC ceramics and resulted in significantly lower values of strain energy density than Cu baseplates. Die-attach reliability was found to be dictated to a greater extent by the local CTE mismatch between itself and the devices or DBC. For a given package design, replacing Ga2O3 devices with SiC devices resulted in improved reliability at the die-attach. The short-circuit withstanding capabilities of Ga2O3 devices were investigated and compared with SiC devices. In the event of a short-circuit scenario such as a thermal runaway, the safe withstand times for Ga2O3 and SiC devices were found to be in the range of 2–3 μs, which is much lower than the recommended time of 10 μs for Si devices.

研究不足

The lower thermal conductivity of Ga2O3 device is a limiting factor and needs to be compensated with innovations in the package design. The conclusions obtained from the modeling study should be considered as design recommendations and any packaging engineer who chooses to rely on the material combinations presented in this paper for their package design should conduct experimental validation tests before constructing the package.