Taiwan-based microLED developer Mikro Mesa announced that it achieved a breakthrough in its microLED transfer and bond process, which now enables the company to transfer 2-5 um microLED chips using a large 4-inch stamp.

Mikro Mesa's new process can transfer color (RGB) vertically-structured microLED chips and create a full-color display. It can be used to create high-density dipslays - up to 1,800 PPI and be used to create large microLED TVs, over 55-inch in size. The new process is a low temperature one (below 200 degrees Celsius) and can be used on flexible substrates - and be also used to create transparent displays.

UK-based GaN-On-Si MicroLED microdisplay developer Plessey Semiconductor announced that it managed to deposit native blue and green microLEDs on the same wafer. Plessey’s new patented process forms microLEDs that exhibit high current density operation and long operational lifetime.

Plessey said that to achieve this important milestone they had to overcome several challenges - including a magnesium memory effect, diffusion from the p-type cladding of the lower junction into the upper junction and the requirement for the precise tuning of the thermal budget during the growth of the second junction to prevent indium phase separation in the blue active region.

Market analysts at Yole Developpement say that microLED shipments will reach over 125 million panels by 2027. In their aggressive scenario, shipments will reach almost 450 million.

Yole says that microLED technologies are advancing rapidly - and on all fronts, but there are still many challenges to overcome before mass production arrives. MicroLED makes a strong case for the AR, smartwatch and automotive market. For the smartphones and TV markets it is less clear whether MicroLEDs could succeed.