Influence of different characterization parameters on the accuracy of LED board thermal models for retrofit bulbs

This paper analyses the influence of several error sources on the thermal impedance curve measurement of multi-LED boards designed for retrofit Solid State Lighting bulbs, using standard instrumentation and simple auxiliary circuitry. The obtained thermal impedance curve is then used for the extraction of compact thermal models, suitable for the prediction of the LED junction temperature under working conditions and for system-level simulation. The main results have shown the relevance of the correct board backside reference temperature measurement and the errors associated to the radiant flux estimation.