Lighting products based on light-emitting diodes (LEDs) are gaining a stronger foothold in many different application areas—consumer, commercial, industrial, and even military products. LEDs provide illumination in everything from automotive headlights to outdoor systems. Key to the design of these LED-based products is proper thermal management: LEDs that run too hot can suffer reduced operating efficiency and dramatically shortened operating lifetimes. Therefore, thermal design becomes critical to maintaining LED p-n junction temperatures that fall within the recommended limits for those devices.
This report will review some of the LED types currently being used and the impact of elevated diode junction temperatures on them. It will also explore different LED thermal-management approaches and materials that have proven effective in reducing LED junction temperatures, as well as briefly look at some of the computer simulation software that can help mitigate the design challenges involved in flowing heat away from the LEDs.