  Besides their electrical properties the optical parameters of LEDs also
depend on junction temperature. For this reason thermal characterization and
thermal management play important role in case of power LEDs, necessitating
both physical measurements and simulation tools. The focus of this paper is a
combined electrical, thermal and optical characterization of power LED
assemblies. In terms of simulation a method for board-level electro-thermal
simulation is presented, for measurements a combined thermal and radiometric
characterization system of power LEDs and LED assemblies is discussed.
Comparison of measurement and simulation results is presented in a case study.
