Optek sent me a DVD they’ve produced on heat management for HB LEDs. The Optek folks are hoping that Mike King can hand it out to LED Workshop attendees at his morning paper, “Thermal management of visible LEDs.” I said, well, maybe, let’s have a look at it first. Mike’s paper, btw, is excellent, full of good stuff while avoiding product promotion.

It turns out that the DVD is a 3-D animation showing all of the losses (listed in the table below)  that can occur in LEDs. Those losses show up as heat, and the challenge is to remove the heat, or preferably, to design the HB LED so that the losses are minimized and never show up as heat in the first place.

In our current love-affair with solid-state lighting, it’s easy to forget that LEDs are only about 18% efficient – the other 82% of the energy put into an LED dissipates as heat. From the Optek DVD the breakdown by type of loss is:

There’s a lot of room for improvement in each of these areas of loss – especially the white light conversion process. As LED technology improves, each becomes more efficient and the amount of heat drops correspondingly. But there will always be losses associated with each step in the light conversion process, so thermal management will continue to be one of the areas of HB LED design that’s all too easily overlooked.

You can attend Mike King’s presentation on thermal management for HB LEDS – and snag one of those DVDs -- at EDN’s free LED Workshop on April 30 at the Hyatt Regency in Santa Clara, CA.