3-D-Lumped Thermal Network Models for the Reliability Analysis of Fan-Cooled Plate-Fin Heatsink

Conventional lumped thermal networks are most commonly used to model the thermal dissipation in the heatsink. However, they lack accuracy in addressing the temperature information when the thermal dissipation performance of the heatsink declines due to the impurities (dust) blocking the air channels. Especially in the reliability field, they cannot provide accurate temperatures to realize the reliability analysis of the cooling system. This article proposes two novel 3-D $RC$ -lumped thermal network models for the reliability analysis of the fan-cooled plate-fin heatsink. In the established thermal circuits, the effects of impurities on the heatsink's thermal dissipation performance are modeled as a few adjustable thermal resistances whose value can be adjusted in accordance with the distribution of the impurities. Moreover, the proposed thermal network models are performed in SIMSCAPE, and computational fluid dynamic (CFD)-based simulations and experimental results are carried out to verify the proposed 3-D thermal networks. It is demonstrated that the proposed 3-D thermal networks enable accurate and fast temperature estimation of the heatsink under different reliability conditions (different impurities' profiles on the heatsink). Therefore, it can be used for the reliability analysis of the heatsink under long-term load profiles when the thermal dissipation performance decreases.