A review of recent research on two-phase thermal management strategies for gallium nitride power electronics applications

The reliability and efficiency of high-power electronic systems are highly dependent on their thermal behavior, as increasing heat fluxes adversely affect device integrity and performance, and speed up degradation. Conventional single-phase cooling solutions cannot manage the high thermal loads generated in today’s high-density applications. The issue is even greater for wide bandgap technologies such as gallium nitride (GaN), in which quick switching and compact device layouts lead to localized heat levels that can be more than 100 W/cm2, remarkably more than what conventional cooling methods can properly dissipate. Due to use of the latent heat of vaporization, two-phase cooling techniques have been proposed as promising solutions to meet these cooling demands. This review concentrates on recent research on passive and active two-phase thermal management strategies, elaborating on their operational principles, thermal performance, and integration issues. Influential design and optimization factors such as geometry, coolant/refrigerant selection, flow rate, saturation pressure and temperature, thermal interface materials, and engineered surface wettability are elaborately discussed. This paper also presents experimental and computational modeling approaches used to investigate boiling dynamics and predict thermal performance in high-power modules. Among the reported strategies, microchannel heat sinks, spray cooling, and two-phase jet impingement show the highest critical heat fluxes and heat transfer coefficients, making them proper candidates for compact GaN-based modules. Moreover, hybrid approaches that combine multiple techniques, e.g., PCM with microchannels or vapor chambers with jet impingement, are increasingly reported as suitable solutions to balance reliability, compactness, and high thermal performance. Future research directions are also presented to back up the development of advanced cooling designs for high-power electronics.