Thermal analysis of the factors influencing junction temperature of LED panel sources

Abstract

Limiting junction temperature Tj and maintaining its low value is crucial for the lifetime and reliability of semi-conductive light sources. Obtaining the lowest possible temperature of Tj is especially important in the case of LED panels, where in a short distance there are many light sources installed, between which there occurs mutual thermal coupling. The article presents results of simulation studies connected with the influence of construction and ambient factors that influence the value of junction temperature of exemplary LED panel sources. The influence of radiator’s construction, printed circuit boards, as well as the influence of ambient factors, such as ambient temperature Ta and air flow velocity v were subjected to the analysis. Numerical calculations were done in the FloEFD software of the Mentor Graphics company, which is based on computational fluid dynamics (CFD). For construction of the LED thermal panel model the optical efficiency ηo and real thermal resistance Rthj-c were determined in a laboratory for the applied light sources.