Index-matching silicones enable high-brightness LED packages

Silicone materials offer HB-LED designers a number of options for chip encapsulation and lenses thanks to their basic physical properties and customizable optical properties. As Bill Riegler and Rob Thomaier of NuSil Technology explain in LEDS Magazine, this can help improve the efficiencies and longevity of HB-LED packages.

The ongoing development of high-brightness (HB) LEDs has resulted in high-output devices that have efficacies approaching 100 lm/W and that are required to operate at increasingly higher temperatures - for example, the new Lumileds Luxeon K2 device operates at a junction temperature of up to 185°C.

Researchers developing products in this area demand encapsulants and lens materials that function well within the device’s operating parameters, and also provide additional optical benefits. Silicone materials can provide the required stability over a wide temperature range, with the added benefit of customized optical properties that provide increased efficiency. (To read more on this topic, go to www.ledsmagazine.com.)