Blog: How Plessey’s microLED tech will bring the next generation of AR headsets, head-up displays and other smart wearables to the mass market

5 June 2019

New LED manufacturing technology is removing the barriers that have held back microLEDs, making them ready to power exciting future display technologies

Plessey has decades of experience with semiconductors and has been producing LEDs in the UK for many years. In 2018, the company added a new specialism: licensing its microscopic light-emitting diode (microLED) manufacturing technology to augmented reality (AR) and Display OEMs.

Why are we focusing on microLEDs? Because with the help of our manufacturing innovations, microLEDs are poised to massively disrupt the global display market.

These tiny LEDs will be at the heart of many cutting-edge display technologies that are going to shape the way we see the world in the future – including AR.

Like OLEDs, microLEDs are well suited to display applications thanks to their high contrast, high speed and wide viewing angle. And they are also significantly brighter, more efficient, longer-lasting and smaller than OLEDs, making them particularly suitable for applications such as smart watches and other wearables, as well as head-up displays and AR headsets.

According to Zion Marketing Research:

“The micro-LED display market was about $272m in 2018 and will rise at a compound annual growth rate (CAGR) of 86.4% from 2019 to $21,129m in 2025.”

Source: Semiconductor Today

However, up until now, manufacturing microLEDs has not been easy – partly because they’re just so small. Using today’s pick-and-place technology, individual micro-LEDs have to be placed on a pitch of less than 50 microns. The equipment used for this is new, expensive and still has productivity issues and as demand grows for higher pixel density, pick-and-place may no longer be viable at all.

That’s where Plessey’s unique technology comes in. The company has spent the last few years developing LEDs made from gallium nitride on a substrate of silicon (GaN-on-Si), instead of the usual sapphire.

GaN-on-Si technology enables the creation of monolithic microLEDs – with multiple emitters on a single chip. This approach brings several key advantages, including smaller pixel pitches of as little as 8 microns, the ability to make larger LED emitters, and better contrast, thanks to GaN-on-Si’s surface-emitting properties. The technique can easily be scaled to 200mm wafers and larger, improving cost and yield.

It circumvents the shortcomings of traditional pick-and-place manufacturing and gives microLEDs the potential to meet the demanding requirements of emerging AR and display applications for smaller, sharper, brighter displays.

But that’s not all: Plessey’s monolithic approach allows microLEDs to be built on a CMOS silicon backplane, so standard CMOS circuitry is easily integrated – a big plus in the high-tech applications at which the technology is aimed.

Plessey has the only monolithic microLED solution currently available and is now licensing the technology to partners to create custom displays and light sources for a wide range of consumer electronics applications and more.

By overcoming the difficulties of manufacturing microLEDs on a commercial scale, Plessey is making microLEDs a mass-market product, and putting itself at the heart of the exciting future of the display business.

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