Parametric Compact Thermal Models of Power LEDs

Light-emitting diodes are nowadays the most dynamically developing type of light sources. Considering that temperature is the main factor affecting the electrical and lighting parameters of these devices, thermal models are essential subcomponents of the multidomain models commonly used for simulation of their operation. The authors investigated white power light-emitting diodes soldered to Metal Core Printed Circuit Boards (MCPCBs). The tested devices were placed in a light-tight box on a cold plate and their cooling curves were registered for different diode heating current values and various preset cold plate temperatures. These data allowed the computation of optical and real heating power values and consequently the generation of compact thermal models in the form of Foster and Cauer RC ladders. This also rendered possible the analysis of the influence of the considered factors on the compact model element values and their parametrization. The resulting models yield accurate values of diode junction temperature in most realistic operating conditions and they can be easily included in multidomain compact models of power light emitting diodes.