Plessey Semiconductors, a company known for its gallium nitride on silicon LED technology, announced the company’s intent to be the first to market with a monolithic microLED based display. Several companies so far have showcased prototype microLED displays. However, no firms have released microLED display products yet. Also, Plessey is apparently one of the few to pursue microLED displays with GaN-on-silicon technology.
The company touts the superiority of its GaN-on-silicon approach for fabricating microLED displays. Hence, Plessey commenced an extensive licensing program through which the company will license out its GaN-on-Silicon expertise to microLED makers. The concept of a microLED display is a technologically tantalizing one that may meet consumer demand for ever-higher resolution, low power consumption, and low-cost fabrication technology. However, the display industry has to overcome several technical hurdles.
While no monolithic microLED displays have reached the market so far, the demand for such technical capabilities has led Yole Développement to forecast that the market could reach up to 330 million units by 2025. Apple, for example, is betting that microLED display technology will supersede OLED displays in the next several years
Plessey contends that its GaN-on-Silicon is the only technology platform that can address all of the technological challenges related to cost-effectively fabricating microLED displays at high volumes. Plessey hopes to demonstrate its expertise by being the first to produce a monolithic display based on microLEDs fabricated utilizing a GaN-on-Silicon technology.
“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,” explained Michael LeGoff, CEO, Plessey Semiconductor.
“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.”
Non-Monolithic Approach to MicroLED Displays Requires Pick and Place Equipment
One of the primary challenges of manufacturing such displays employing a non-monolithic approach is placing the LED chips onto a CMOS backplane. However, this non-monolithic approach is currently achieved for prototypes with pick and place equipment which individually places every LED on a pitch of less than 50μm. As the pixel density of displays improves and pitch decreases, using pick and place equipment becomes less technically and commercially feasible.
According to Plessey, a monolithic process, on the other hand, removes the need for chip placement, and can enable smaller and higher resolution displays for applications such as virtual reality (VR), augmented reality (AR), and head-up displays. As the only commercially available monolithic solution, Plessey says its technology doesn’t need pick and place equipment and doesn’t suffer from the associated issues with productivity.
Plessey points out that a fully monolithic strategy also supports the integration of the standard CMOS circuitry needed for driving microLED displays, and this strategy also enables the integration of high-performance graphics processing units (GPUs). Standard CMOS manufacturing methods can produce all of the driving and graphics processing unit circuity needed. Plessey says that by solving all of the major technical issues beforehand, licensees get instant access to a technology platform that is ready for volume production.
“GaN-on-Silicon is the only technology that makes sense in terms of scalability and performance,” commented Dr Keith Strickland, CTO, Plessey Semiconductor.
“It offers better thermal conductivity than Sapphire and higher luminosity than OLED, which is why this technology is widely acknowledged to be the only one that can deliver high resolution, high luminance displays.”