The automotive industry is highly competitive and manufacturers are often keen to explore bleeding edge technologies. Automotive lighting is no different – from Citroen’s directional headlamps on the DS in 1967, to BMW introducing High Intensity Discharge (HID) lights on the 7-Series in 1991, and more recently OLED interior lights, automotive lighting has always embraced the latest thinking. Whilst some of these technologies may have sunk without a trace (in the case of directional headlamps only to resurface a few decades later) many go on to become ubiquitous.
Whilst the automotive sector is primarily driven by safety and performance requirements, fashion and prestige also have a central role to play. New technologies tend to start off in the high-end marques and work their way down towards the economy ranges over time. Audi offered the world the first glimpse of LED lighting with the daylight running lights (DRL) on the R8 in 2004, now they’re standard throughout Audi’s range. Rear lights, stop lights, daylight running lights, indicators and interior lighting are now all dominated by LED technology. Even for older vehicles, LED substitutes for incandescent bulbs are available in many automotive parts stores.
Headlamps, being far brighter – and therefore far hotter – than any other automotive light source have proven the most challenging to replace with LEDs. By 2010 the first mechanically controlled LED headlamps were introduced on the BMW 7 series (the very same model that first featured HID lamps in ‘91). Now many manufacturers offer LEDs as standard or as an upgrade option on new models, but halogen and HID still dominate the market.
However, alternative solutions are already out there (for full beam applications at least) using a technology more associated with science fiction. Powerful lasers, wavelength converted by a phosphor, bounced off mirrors and put through a lens, create a point light source a thousand times as bright as LEDs for around half the power. This light reaches twice as far as an LED headlamp, offering massively improved vision for the driver. However, it also costs as much as a new small car so until the price drops it really isn’t an option for the economy end of the market.
Forward facing cameras can capture real time feedback from the road and provide feedback to the system to allow headlamp beam shaping to be completely automated, eliminating glare for oncoming drivers. Later this controllability may extend to benefit cyclists and pedestrians as well.
However, there is the sticky issue of heat to deal with. All this technology relies on High Brightness LEDs (HB LEDs) and solid state lasers. Whilst these are considerably more efficient than incandescent lights they still get seriously hot and need cooling. Failure to keep them cool doesn’t just result in a burnt smell – it leads to the catastrophic failure of the device itself. Really not ideal if you’re driving home on a dark night.
This is where Nanotherm comes in. We work with leading LED and automotive manufacturers on both L1 (the packaged HB LEDs themselves) and on L2 modules – the PCBs that the LEDs (either packaged, bare die or CSP) are mounted onto. Our award winning solutions include our Metal Clad PCBs (MCPCBs) that offer a thermal performance of 115W/mK, and mechanically robust alternatives to ceramic for LED packaging with thermal performance of 152W/mK – a performance that rivals exotic material such as aluminium nitride. Unlike expensive ceramics our materials can be manufactured in large panels. By leveraging economy of scale our thermal management substrates drive down cost, helping to make LED lights affordable for all drivers.