Thermal management: A key point for the integration in solid state lighting systems

Solid State Lighting technologies are becoming more and more attractive in the lighting market. Thermal management is a key issue, which impacts efficiency but also colour stability and reliability of LED-based systems. In this paper, we describe and discuss such issues through various examples of different projects by analysing both the heat transfer mechanisms and their impact on the choice of materials and integration technologies. Transient thermal analysis are performed allowing to derive both the junction temperature and the discrete thermal resistances of the systems. The measurements are supported by Infrared thermography as well as Numerical Finite Elements Modelling (ANSYS® software). Results on various LED dies, package configurations, board types are presented with the impact on LED light flux. In addition, we present results on LED light engines based on the Chip On Board technology showing the benefit of this technology. Finally, the optimization of the heat sink is presented on a LED retrofit MR16 lamp.