Putting the spotlight on LED thermal design

3 mins read

Earlier this year new research from Future Facilities – maker of the 6SigmaET thermal simulation software – revealed the top challenges and trends in the LED industry for 2020 in its Thermal Focus project report.

With LED usage becoming more common the research, which New Electronics reported on in our last issue, identified a number of key trends around the need to incorporate LEDs into increasingly compact designs that must be turned around in record time.

These trends included greater customisation, improved reliability in a wider variety of climates and environments, and the need for faster thermal simulation tools.

According to Chris Aldham, Product Manager at Future Facilities, “Today’s thermal simulation platforms must offer an exceptional level of accuracy to prevent overheating and produce reliable end products. For LED devices, everything depends on temperature, but temperature depends on everything else. It’s so interlinked that it’s impossible to look at it in isolation; the entire design process matters.”

According to Aldham, the Thermal Focus project was launched because of a need to better understand the engineering community and to be able to support further innovation in terms of thermal simulation products.

“Our industry research projects are a huge part of that process. In 2017 we surveyed over 350 design engineers to understand their current and future design requirements. In 2018, we spoke to 170 thermal simulation professionals to find out exactly what they needed from our platform.

“Then last year, we launched the first of our ‘Thermal Focus’ groups. The idea was to bring together thermal experts from some of the world’s biggest electronics brands, discussing their current thermal simulation challenges, and the trends that they believe will shape the future of electronics and thermal design.

“The first of these groups focused in on IT, bringing together engineers from HP, Facebook and other leading brands. Following the success of this event, we wanted to explore more industries and dive even deeper into how real-life engineers are using our thermal simulation products.”

The focus on LEDs was due to the fact that it is a hugely exciting time for the LED space, Aldham explained.

“In the next few years alone, the global market for LEDs is forecast to be worth over $50 billion. LEDs are energy efficient, they’re cost effective, and they’re environmentally friendly. They really are a hugely versatile bit of kit, and their uses are only going to grow. They are also really thermally interesting. They don’t like getting hot and every aspect of an LEDs performance (light output, light colour, lifetime, etc.) is temperature dependent.

Gathering expertise

“At Future Facilities we’re also lucky enough to work closely with a lot of LED and lighting brands, so getting in touch with the likes of Signify, OTS (Optimal Thermal Solutions) and Thal Technologies was a great way to gather expertise.”

The project has generated a number of key things engineers need to consider when thinking about the thermal design of LEDs.

According to Aldham, “One of the things that was most talked about by our industry panel was the realities of designing LEDs in 2020. Shrinking space is a huge issue in both consumer and industrial applications.

“To create smaller, lighter and thinner LED devices, a growing number of engineers are starting to specify LEDs as ‘chip-scale packages’ (CSP). “Simply put, CSPs can be grouped very close together, creating clusters of extremely power-dense modules within these compact designs. But a consequence of increased power is increased temperature. Such close groupings of high-powered LEDs will inevitably generate a large amount of heat, so effective thermal management is vital.

“The other big issue that was discussed was design time. LED manufacturers and device designers are working to increasingly condensed timescales, with turnaround time for an entire design project sometimes clocking in at as little as two weeks. The pressure to get to market as quickly as possible means designers often can’t evaluate how components work in tandem as carefully as they’d like. These sub-optimal designs can lead to product failures, poor light output or long-term reliability issues. It’s vital that time is factored into the initial design processes to adequately account for possible thermal complications.”

Looking to the future, Aldham said that participants in the industry panel all had very different ideas as to what needed to be prioritised.

“But there were some clear themes that started to show through across the board,” he suggested.

“LED customisation is clearly going to be a big deal. As LEDs enter increasingly niche markets, they’re going to need to be customised. As such, it’s vital that we look at potential specialised applications from a thermal point of view. Customised designs will inevitably mean unexpected thermal challenges.

“The second big theme that everyone agreed upon was the IoT. With the rise of the internet of things, smart lighting solutions and a growing focus on energy efficiency, LEDs are going to have a major role to play in future tech. This, however, will mean LEDs also operating in a whole host of

rugged environments (and varying temperatures) that they previously wouldn’t have been exposed to. This is going to mean big changes for the industry and a significant investment in thermal simulation and design.”

The Thermal Focus group project is likely to continue this process, said Aldham.

“Right now, we’re looking at a lot of content related to the automotive and aerospace industries, as we’re very keen to better understand exactly how engineers in these spaces are managing thermal considerations, using simulation, and what their plans are for the future.

“If any readers work in these spaces and want to be involved, do get in touch with us via the 6SigmaET website. We’re always on the lookout for new insights and opinions so very happy to hear from anyone who can help,” he added.