Table of Contents
ISRN Optics
Volume 2013, Article ID 385345, 5 pages
Research Article

Combined Experimental and Monte-Carlo Ray-Tracing Approach for Optimizing Light Extraction in LED COB Modules

CEA-Leti, Minatec Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France

Received 6 May 2013; Accepted 26 June 2013

Academic Editors: L. R. P. Kassab and Y. S. Kivshar

Copyright © 2013 Marianne Consonni et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


High-power light-emitting diodes (LEDs) for lighting applications require a high-efficient packaging to optimize their performances. Due to its high thermal dissipation potential, the chip-on-board (COB) technology is widely used for developing high-power lighting sources. In order to optimize the optical properties of such sources and to propose high optically efficient encapsulation geometry, ray-tracing simulations have been performed. The impact of the shape and volume of the silicone encapsulation on the light extraction and on the intensity distribution of the module was derived. Then, simulation results were correlated with experimental measurements on blue light-emitting COB sources. It is shown that a nearly hemispherical encapsulation with a minimal volume of 5 to 10 mm3 for a 1 mm2 LED die is the optimal configuration regarding both the light extraction and the intensity distribution.