While I was waiting for the last few people for my presentation ‘Thermal Design: A Key Part of the Electronics Design Flow’ at the UK Solutions Expo at the Heritage Motor Center in Gaydon a couple of weeks back I thought I’d poll the audience with a couple of questions. It’s rare that I get to speak to an audience of electronics engineers, so I was interested to see how they view thermal design.
First I asked “Who thinks that thermal is an electrical problem that should be solved as part of the electrical design?” About 60% of the audience put their hands up. I was pleasantly surprised at how high this was as it shows the electronic engineers feel responsible for the heat produced, AND that they have a role in dealing with it.
There’s a lot electronics engineers can do, from just focusing on low power energy efficient design in general, to more specific actions to improve the thermal design, like being conscious of the thermal impact of a PCB layout – something that can be assessed with HyperLinx Thermal or FloTHERM.PCB. Then there’s including on-chip temperature sensors that can be monitored during operation, and incorporating control circuitry for a temperature controlled fan in case the fan speed needs to be increased to keep components within spec.
I then asked “Who thinks that thermal is a mechanical issue that should be solved as part of the mechanical design?”
About 40% of the hands went up. This fits with the previous show of hands. As I mentioned, I was expecting more as most thermal design software is aimed at the mechanical engineering community. FloTHERM is the clear market leader, used from conceptual design to post-design verification by both thermal experts and generalists.
FloEFD is fully embedded in mechanical CAD environments like ProENGINEER, CATIA V5 and SolidWorks, making it ideal for companies with heavily MCAD-centric design flows.
The last question I asked was “Who thinks it’s a trick question?”
A couple of hands went up. Not sure if these guys had their hands up earlier, but hey – I didn’t say you couldn’t put your hand up more than once!
So, what’s the answer? Should thermal be tackled as part of the electronic design flow or the mechanical design?
The answer is “It depends.”
Some problems are best solved at source as part of the electronic design flow, for example confirming the layout will be thermally acceptable before the PCB is routed, whilst others are best resolved as part of the mechanical design, for example including a heat pipe to move heat from a particularly power hungry component like a CPU or GPU, to a remote heat sink where more cooling air can be delivered.
As the saying goes, “To a hammer every problem looks like a nail”. If your company thinks of thermal as an electronic issue then they’ll naturally try to fix it as part of the electronic design. If they think of it as a mechanical issue then responsibility will almost certainly reside with the mechanical design department, and the risk is that issues won’t be addressed early enough.
Everyone involved in the product creation process has a role to play in ensuring that the thermal design is done upfront from the conceptual design phase, with concurrent CFD – simulations performed concurrently with design changes, resulting in a fluent design process with no nasty surprises late in the design.
What’s most important is that nobody in your empire regards it as Somebody Else’s Problem, otherwise vital opportunities will be missed leading to a more time consuming and costly solution later in the product creation process.
Arguably only a couple of people got it right, but the best response would have been for everyone to put their hand up in response to both the first and second questions. Maybe I’ll ask it at other venues and see how the answers change over time