LED lighting is one of the fastest growing markets for electronic components of all shapes and sizes. John Cafferkey, marketing manager, Cambridge Nanotherm, predicts new applications such as lightbulbs which could be wireless hotspots and highlights the importance of thermal management in LED design.
What are your predictions for the general LED market in 2016?
The view we’re getting from our customers is that growth will be driven by the general lighting segment. This is a big change from a few years ago when growth was dominated by the back light TV segment.
One interesting statistic that market analysts Strategies Unlimited uncovered is the rise of high power and super-high power LEDs. This goes against the perceived wisdom that mid power LEDs would dominate general lighting and speaks a lot about the benefits of chip-on-board (COB) LED device.
These are classed as super high power and are set to enjoy the biggest gains as a percentage of the market, especially in the lighting fixtures market. There are a number of reasons for their success – not least that they are much simpler to work with compared to SMD packaged LEDs.
What general trends do you predict we’re going to see in the 2016 thermal management market, and how do these relate to what’s happening in the LED market as a whole?
Thermal management of LEDs is stepping up with the rise in high and super high power LEDs. Market analysts Yole predict that ceramics such as aluminium nitride will become increasingly prevalent in COB LED and high power packaged LEDs as power densities continue to increase.
What new LED technologies do you see emerging or growing in popularity in 2016?
One of the buzzwords to come out of the LED industry in 2015 was “human-centric”, i.e. using light to improve the performance and well-being of people. This is being seen by many in the industry as the LED’s killer USP, as it’s only possible with the control of wavelength and light quality that can be achieved by using LEDs.
As an example the use of different wavelengths of light to help balance children’s moods – warmer light when it’s quiet time and colder, bluer light when they need stimulating, has been trialed in primary schools. This taps into our hardwired circadian rhythms and is one to watch for the coming year.
The controlability of LEDs is relevant for car headlights. With LEDs it’s possible to form light in such a way that the road can be lit up as if with a full beam without dazzling oncoming traffic. This has big implications for car safety and is starting to be rolled out in higher end car marques.
Possibly the most profound change we are seeing is the introduction of additional technology in LED modules. Lighting is getting smarter with communication modules such as Bluetooth and ZigBee enabling smartphone-controllable lights as part of an IoT ecosystem.
One very interesting technology that’s being developed is Li-Fi – delivering data using the visible spectrum rather than radio waves at speeds upwards of 1Gbit/s. This can be built into LED modules so lightbulbs could soon become wireless hotspots.
How will these affect the thermal management market?
Clearly the increase in power required for devices such as car headlights will need more sophisticated thermal management, but there’s also a requirement for the various device-on-board modules – many of these devices need to be operated at relatively low temperatures so maintaining a consistent (low) temperature is critical.
Do you foresee any new and interesting technologies emerging in the thermal management market? For example new materials or approaches?
The thermal management market is an area where there’s always a lot of research. There’s been a move by the aluminium nitride manufactures to create more cost effective (but thermally less efficient) material and there’re always incremental developments in MCPCB dielectrics.
Our latest product, Nanotherm DM, which is a more rugged alternative to aluminium nitride, recently won the Elektra Awards best new LED product.
Do you forsee any existing but underexploited thermal management technologies growing significantly in popularity in 2016? Why?
The rise of the filament bulb! There was a notable increase in the number of filament style LED bulbs on show at LED events in 2015. We expect to see these increasing in popularity as they offer a perfect form/fit/function replacement for incandescent bulbs.
Expect to see increasingly funky filament designs on the market in 2016. The filaments in question are rows of small LEDs mounted on formable dielectric substrates with good thermal conductivity to keep the LEDs cool. This presents some interesting options for thermally effective flexible substrates.
What LED applications do you think are going to be the biggest factor in driving the need for effective thermal management technologies?
The rise in super high power COB LED devices and the high power packaged LED market is ramping up demand for ceramic substrates. Analysts are suggesting supply is close to maximum capacity, which means pricing and availability for companies without guarantee agreements are going to be challenged in terms of making product deliveries. This will provide a perfect window of opportunity for competing materials to enter the market.
Which LED applications do you think will see a downturn in 2016?
The LED TV market is in decline – the market has hit saturation point and with new technologies such as OLED competing for the upgrade and replacement market it’s a shrinking pool. The same is true of screens and backlights for smart phones.
Of the various ways of mounting LEDs (flip chip, chip 0n board, etc.), which do you think is going to see the most significant growth in 2016, and why?
Chip Scale Packaging is really taking off. This approach (similar to a flip chip) removes the requirement for level 1 packaging. The CSP LEDs are simply mounted directly onto a PCB to make a COB device. Chip scale packaging ticks all the boxes of smaller form factor, better performance, improved reliability and, in theory, reduced cost.
By fabricating chip scale packages with integrated optics it also allows chip manufacturers to secure higher average selling price for their products.
How is this going to affect the world of thermal management?
It will move the requirement away from L1 packaging substrates to L2 modules (basically metal and ceramic PCBs). In luminaire design, more attention is going to have to be paid to the selection and deployment of these systems components as a larger portion of the LED chip construction loses its customizability. This will naturally have a snowball effect in driving the focus over towards system thermal management and cost reduction.
Do you have any general or specific predictions regarding the pricing of LEDs and thermal management technologies in 2016?
Expect prices to continue to drop as manufacture transitions to Asia. LED manufacturers are looking to reduce cost by cutting the costs of packaging process with CSP and ultimately wafer level packaging. LED manufacturers are looking at increasing the volumes – Osram are looking at new production plants in Malaysia for example.
The very considerable and strongly protected IP content of LEDs seems to be being effective at preventing copycat manufacturing from flooding Western markets, as has happened with so many other commoditised industries. A combination of new technology, lower cost manufacturing and economies of scale should help to drive down the overall lumens/$ cost and ultimately this is what will drive mass user adoption.
Anything else you would predict will happen in the thermal management industry in 2016?
The lighting industry really wants to find a way of adding value to luminaires so they do more than simply produce light at the flick of a switch. This could be by dispensing with physical luminaires to make “light walls”, or adding technology functions such as circadian rhythm control or Li-Fi. At the moment there is no clear direction, but at some point, something will suddenly become fashionable and that will be the market driver. Spotting this breakout to get in at the beginning is going to be tough, but fascinating for those without a horse in the race.
What would be your number one piece of advice for someone looking to purchase a thermal management technology for LED applications in 2016?
Take time to understand the physics of thermal design and approach it from a system level perspective. It is a complex subject – but managing the thermal performance of the system drives the lifetime of the LED and therefore the overall cost of ownership of the lighting solution.
After all, what, exactly, is temperature? The ease of confusion is often exploited in product marketing material to make a product appear to be somewhat better than it may be.
The numbers are probably not wrong, as they are obtained from standardized tests, but can easily lead to the uninitiated making an unwise choice and suffering the consequences in poor product performance.