Thermal Analysis and Modeling of LED Arrays Integrated With an Innovative Liquid-cooling Module

The efficiency and reliability of solid-state lighting devices strongly depends on successful thermal management. High-brightness light emitting diodes (LEDs), as a strong candidate for the next generation, general illumination applications, were developed by improving luminous efficiency and integrating multi-chips within limited areas. This resulted in the thermal management challenge that is able to dissipate extremely high heat flux at low thermal resistance. This research explored the thermal analysis and modeling of LED arrays integrated with an innovative liquid-cooling module. A series of numerical simulations were done with pin arrays patterns, cooling liquid inlet velocity, and allowable module power dissipation, to investigate the thermal performance of liquid-cooled MMC module. Simulation results, in forms of maximum junction temperature, show that the liquid-cooled module reduces the junction temperature of the chips, and improves the heat dissipation capability of LED arrays, improving the operating efficiency, enhancing the device longevity and leading to the increased integration density. However, the results also demonstrated that, without proper design the base plate temperature of the module is non-uniform, and the downstream or edge chips were hotter than the upstream or central chips. This may accelerate thermal runaway problems and reduce the reliability of the LED arrays device. Detailed fluid field and heat transfer analysis were performed using a computational fluid dynamics (CFD) technique to optimize the internal geometry of module, achieving the best thermal performance of the liquid cooled MMC module. The results also suggest that further improvements in performance are feasible