Check it Out: Solving the System-Level Thermal Management Challenges of LEDs

By Anthony J. Lockwood

Dear Desktop Engineering Reader:

The synopsis of “Solving the System-Level Thermal Management Challenges of LEDs” is that you need to take into consideration and manage thermal conditions when developing LED technology, and doing so is a tricky business. The upshot of the paper is that mechanical designers can work on and solve LED thermal issues from the earliest stages of the development process using Concurrent CFD (computational fluid dynamics) analysis technology. The logistics of the paper are that it’s an 8-page PDF that you sign up for then download from the link they e-mail you. I know many of you are shy about doing that, but this is worth it. Here’s why.

The paper starts with an extensive discussion of why LEDs have thermal issues that other lighting options do not have. The basic problem is that LEDs generate heat that can reduce their life, alter colors, and mess up the benefits that make their use so attractive. And whereas the filament in an incandescent light bulb radiates its heat to the environment, an LED relies on conduction to transfer heat to the system enclosure and from there to the environment. This means you got to think about heat sink designs, high efficiency circuit boards, high thermal conductivity enclosures, and other thermal design techniques when designing an LED device.

After discussing the thermal issues, this paper turns to the role simulation plays in addressing these challenges. Obviously CFD plays a big part, but CFD can be frightening since it’s so over the top high level, right? Well, here the paper turns to a pitchless pitch for CAD-embedded CFD analysis by design and mechanical engineers. I say “pitchless pitch” because this paper is so for engineers that Mentor Graphics does not seem obligated to even mention the name of their CAD-embedded CFD product (FloEFD).

“Concurrent CFD” is what Mentor Graphics calls its CAD-embedded CFD technology. And it’s not CFD lite, even if design and mechanical engineers feel at home using it. But it is CFD that automates the steps of building a CFD model then handles the possible thermal transfer mechanisms to accurately analyze an LED device as well as other thermal problems. The paper explains how CFD embedded in your CAD system captures the full geometric complexity of your LED design and enables you to analyze and optimize a design as you create your model. It does so with an in-depth, well-illustrated example analysis.

Finally, this paper wraps up with a section on how simulation and physical testing validate each other. Imagine, a paper about simulation technology acknowledging that these two engineering approaches are symbiotic.

I admire the way Mentor Graphics does its white papers. The paper at the other end of today’s Check It Out link is a good example of why I say that. Not only does it have some technical meat, it’s just darn interesting.

“Solving the System-Level Thermal Management Challenges of LEDs” is written as if you’re a smart person but not necessarily conversant in the nuances of LED design and the complexities of heat transfer analysis. That in and of itself might be cause enough for you to check out this paper.

Thanks, Pal.– Lockwood

Anthony J. Lockwood
Editor at Large, Desktop Engineering

Solving the System-Level Thermal Management Challenges of LEDs