5 January 2018
Plessey aims to launch first monolithic microLED displays in first-half 2018
Plessey Semiconductors Ltd of Plymouth, UK has committed to being first to market with a monolithic microLED-based display based on gallium nitride (GaN)-on-silicon. Market research firm Yole Développement forecasts that, as demand is accelerating, the microLED display market could reach 330 million units by 2025.
Plessey has also commenced an extensive licensing program that will see it license out its GaN-on-Si expertise to microLED manufacturers, in line with its new business strategy of aiming to become the photonic industry’s foremost technology platform provider.
Claiming that GaN-on-Si is the only technology platform capable of addressing all the challenges involved with manufacturing microLED displays both in high volume and cost-effectively, Plessey intends to demonstrate its expertise by being first to manufacture a monolithic display based on microLEDs fabricated using a GaN-on-Si approach.
“We made the decision to become a technology platform provider in order to get our technology out to the widest possible manufacturing base to meet this growing demand,” says CEO Michael LeGoff. “By being the first to market with a monolithic microLED display we will be demonstrating our expertise and the ability to access our proven turn-key solution, enabling manufacturers to ramp up the development and production of microLED displays to address emerging applications,” he adds.
One of the main challenges involved with manufacturing microLED displays using a non-monolithic approach is the placement of LED chips onto a CMOS backplane, currently achieved using pick-and-place equipment. This involves the individual placement of every LED on a pitch of less than 50μm, requiring new and expensive equipment that is subject to productivity issues. As the pixel density of displays increases and pitch reduces, pick-and-place becomes less feasible both commercially and technically, says Plessey.
Moving to a monolithic process removes the need for chip placement and will enable smaller and higher-resolution displays for a range of applications, including virtual reality (VR), augmented reality (AR) and head-up displays. Claiming to have the only commercially available monolithic solution, Plessey says that its technology does not require pick-and-place equipment and is not subject to the associated productivity issues.
A fully monolithic approach also supports integration of the standard CMOS circuitry necessary for driving microLED displays, as well as the close integration of high-performance graphic processing units (GPUs), all of which can be carried out using standard CMOS manufacturing methods. By solving the major challenges, licensees gain instant access to a technology platform that is ready for volume production, says Plessey.
“GaN-on-silicon is the only technology that makes sense in terms of scalability and performance,” reckons chief technology officer Dr Keith Strickland. “It offers better thermal conductivity than sapphire and higher luminosity than OLED [organic light-emitting diodes], which is why this technology is widely acknowledged to be the only one that can deliver high-resolution, high-luminance displays,” he concludes.