Electrochemical alumina technology for high-brightness LED applications

Abstract

High temperatures near light-emitting regions are common for high-brightness LED systems. The cooling problem for these devices can be solved only by effective heat sink from the light-emitting region to the cooler environment. We propose the most effective heat sink for the high-brightness LED systems fabricated on the anodized aluminum substrates. 30 – 50 µm thick nanostructured alumina layer formed by the electrochemical alumina technology offers good electrical isolation and excellent thermal transfer. Copper conductors are applied to the alumina layer and light-emitting diodes are mounted directly on the surface. This approach allows the most important heat resistance component, i.e. a dielectric substrate, to be excluded. As a result, the record low heat resistance is reached and the heat sink is more efficient. So, the electrochemical alumina technology allows the heat sink problems that were considered as an insurmountable obstacle to be solved.