Sunghyun Pyun's research while affiliated with Hanyang University and other places

This study proposes a novel design for a pin-fin heat sink and optimizes it to enhance the thermal performance of double-sided cooling (DSC) power modules applied in inverters for xEV applications. The circular pin-fins are conventionally adopted in automotive power modules. In this study, to decrease the junction temperature with the maximum ( T_j,max ) of IGBT bare-die, the pin-fin shapes are modified from conventional circular to a rounded rectangle. For further T_j,max reduction, the angle of the rounded-rectangular pin-fin is tilted. These shape modifications reduce the IGBT’s T_j,max thanks to three main reasons: (1) increased coolant velocity by reducing pin-fin spacing, (2) reduced wake behind the new pin-fin shapes, and (3) increased turbulence in the coolant by tilting the pin-fin angle. Finite volume method (FVM) simulations demonstrate that the best performance is achieved when the rounded-rectangular pin-fin is tilted by +15°. This enhanced new pin-fin design was fabricated and measured to demonstrate that the maximum device junction temperature was reduced by approximately 15.5 °C compared to a conventional counterpart. Moreover, the module thermal resistance was also decreased from 0.298 °C/W to 0.228 °C/W (by ~23 %) with an acceptable pressure drop. These results demonstrate that the proposed new pin-fin design is an effective heat-sink solution for indirect double-sided cooled modules and, once enhanced, can be comparable with direct cooled modules.

This paper proposes the use of a perforated pin for a SiC power module heatsink in automotive applications. Both simulations and experiments demonstrate how the proposed new pin design can enhance cooling performance. We extensively investigate the shapes and locations of pin–fin structures, commonly used for power module cooling. However, due to limitations in geometrical optimization for improving cooling performance, we introduce a novel concept: the perforated pin. Ansys Fluent is utilized to conduct a preliminary analysis of the new pin design prior to prototyping and testing with a specially designed apparatus. Our proposed design is compared with three conventional alternatives: a standard cuboidal pin–fin (reference), a cuboidal pin–fin after geometric optimization, and cylindrical pin–fin cooling structures. The results reveal that the proposed design reduces the maximum device temperature while slightly increasing pressure loss. Notably, the pressure loss increment of our design is only 36.6% compared to the geometrically optimized cuboidal pin–fin, which exhibits a 151% increase in pressure loss alongside improved cooling performance.