Thermal performance and placement design of LED array package on PCB

This paper reports the thermal performance of a high-brightness light-emitting diode (LED) array package with a novel placement method on a metal core printed circuit board (MCPCB). The precise heat transfer analysis and modeling using computational fluid dynamics (CFD) were performed according to the practical working conditions of the LED array. The surface temperatures of the LEDs having the developed placement method were monitored and compared with that of LEDs using a conventional placement method. Emphasis was placed upon investigating how the radiant flux, efficacy, and uniformity of illuminance changed in accordance with the method. Thermal distribution of a commercial LED product having 36 high-brightness LEDs using the developed placement method is compared to that of the LED product having the original design. Results suggested that the new placement method could lower the individual LED surface temperature by rearranging the thermal distribution of the LED array. As a result, the overall heat dissipating capability of the LED array to the PCB and hence LED efficacy was improved.