Researchers from the Korea Advanced Institute of Science and Technology (KAIST) developed a new process that enables the fabrication of highly dense MicroLED displays - up to 63,500 PPI (!).

The technique involves stacking RGB LEDs in three dimensions and a semiconductor patterning process. Stacking LEDs one on top of the other creates color interference issues, and to overcome this the researchers deposited an insulating film between the layers. This also improved the efficiency of the microLED devices.

Seoul Viosys and Seoul Semiconductors have jointly developed a new MicroLED technology, called Micro Clean LED that basically packages three separate LEDs (red, green and blue) into a single "one-single MicroLED pixel".

The idea is that these packaged colored pixels will be easier to transfer to the target substrate compared to the transfer of three different LEDs. The package itself does not contain any driver ICs.

MICLEDI, established in Belgium in 2019 as a spin-off from IMEC, announced that it raised €4.5 million to develop next-generation microLED microdisplays for AR applications.

MICLEDI says that it displays will be the smallest and possible on the market - enabled by its new integration technology for microLED on 300 mm wafers, developed in collaboration with imec.

In December 2019, China-based display maker Konka launched its tiled large micro-LED displays, under the APHAEA brand. The company demonstrated two such displays (4K and 8K) at CES 2020, as you can see below:

Konka's MicroLEDs are modular displays (similar to Samsung's The Wall and Sony' Crystal LED displays).

Taiwan's Industrial Technology Research Institute (ITRI) demonstrated a 16.7" microLED display "module" that was produced by directly mass transferring micro-LED chips onto a PCB backplane.

ITRI developed its own mass transfer tech, and uses microLEDs provided by PlayNitride , PCB backplanes provided by Unimicron and drivers and assembly by Macroblock. The 16.7" display is made by tiling 15 modules 6x10 cm each (45,000 LEDs). The microLEDs are <100um in pitch.

Shanghai-based Micro-LED microdisplay developer JBD unveiled two new Micro-LED microdisplay prototypes. First up is the JBD5UM720P-G, a 0.31" 720p (1780x720, 5,000 PPI) display that features a typical brightness of 3 million nits (!). This is a monochrome green (530 nm) display.

The second display, the JBD25UMFHD-B is a higher density display, at 10,000 PPI it achieves a 2560x1440 resolution in the same 0.31" size. This is a monochrome blue (455 nm) display that has a brightness of 150,000 nits. The display's refresh rate is 360Hz.

The MicroLED-Info team is excited to announce its attendance at the Mobile World Congress 2020 on February 24-27 in Barcelona, Spain. The Mobile World Congress (MWC) is the world's largest gathering for the mobile industry, organized by the GSMA. It features a large exhibition, conference programme and networking opportunities.

We are looking forward for a great event and great new microLED prototypes and technologies on display.