Norbert P. Engelberts

Thermal Design and Management of High Power LEDs . by Norbert P. Engelberts,

Light emitting diodes (LED) used to have a strong presence in instrumentation and computer as visual indicator for signal integrity and device operations status. In these applications, LEDs were ideal since they are highly reliable, low power while requiring little to no maintenance. The latter features of LEDs piqued the market interest for their use not only as indicator but also as lighting devices. Since illumination has become the focus, the power consumption of LEDs has gone up dramatically with device heat fluxes rivalling CPU and other semiconductor packages.� As the result, thermal management of LED applications has taken the centre stage for their successful implementation.

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It�s important to remember that an LED is not a high temperature, filament-type light source. Most LEDs are designed in SMT (surface mount technology) or COB (chip-on-board) packages. But, while a single LED is a cold and efficient light source, high-power LED applications, including arrays of LEDs, need thermal management similar to other semiconductor devices. High temperatures not only degrade an LED�s lifetime, but also results in lower light or non-uniform output � effects that can significantly affect the application.

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In this presentation we will demonstrate the required approach for thermal management of LEDs that will enable the designer to select the appropriate cooling solution based on the LED�s junction temperature, and not on the total power dissipation.

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Benefit to the audience.

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The following are the salient benefits to the participants:

• Understanding Why Thermal Management is important � the participants will gain an appreciation as to why thermal management is important for the design of lamps based on LEDs

• Available Cooling Solutions � the participants will be exposed to best-in-class industry practices and the market available cooling for cooling of LED based lamps

• Case Studies, what is possible with good engineering � The case studies that are represented will include some of the cooling solution designs that have been developed by Advanced Thermal Solutions, Inc. A review of these designs will make the audience aware that with excellence in engineering, expensive cooling solutions can be avoided and lesser-cost cooling solutions can be deployed instead.

• Experiment, Measurement of junction temperature � Temperature versus light output. Junction/ board temperature measurements, its effect on board design.