Thermal investigation of a high brightness LED array package assembly for various placement algorithms

This paper presents a thermal management analysis and experimental validation of natural convective heat transfer of a high brightness LED array package assembly in various placement algorithms. The operating conditions include thermal conductivity of the PCB, heat sink design, and LED placement design in a system module. The temperature distribution and heat flow of the LED array package are assessed by thermal profile measurement using an IR camera and thermocouples. In addition, the heat transfer process of the LED array package assembly in natural convection is also simulated using the computational fluid dynamics (CFD) method. The optical performance of the LED array is monitored and investigated in accordance with the environmental variations. The thermal distribution of a commercial high-brightness LED array product using the developed placement method is compared to that of the original design. The change in radiant flux, LED efficacy, and uniformity of illuminance is compared. The results suggest that the new placement method for a LED array can lower the individual LED surface temperature by more than 10%. As a result, the overall heat dissipating capability of the LED array to the surrounding and hence LED efficacy is improved.