A review of existing methods for study and analysis of thermal design of LED lighting products

The lifetime of LED luminaires, made of high power LED arrays, operating under hostile conditions is determined by their thermal design, operating junction temperature and thermal transients managed by the thermal system. Thermal transient characterization is a noninvasive study of the thermal resistance characteristics or thermal design of the LED luminaire. This procedure can identify anomalies in the thermal design or irregularities in the heat conduction path from the LED junction to the ambient. Any increase of thermal resistance along the heat conduction path can cause excessive junction temperature build up and cause early failure or increased degradation of device. The scope of this work is study the existing method for thermal transient characterization and analysis using the evaluation of the structure function of the heat conduction path of LED lighting product. It can be concluded that structure function approach is a very superior procedure for thermal transients characterizing the heat conduction path and estimating junction-to-ambient thermal resistances.