Flexible MicroLED - Page 4

Researchers from the University of Texas at Dallas developed a new method to create highly flexible microLED chips, that can be folded and twisted. The LEDs are detachable, and can be attached to almost an surface.

The researchers used remote epitaxy, to grow the LED crystals on a sapphire crystal substrate, coated with a one-atom layer of 2D graphene, which prevents the LED to stick to the sapphire substrate.

Taiwan-based display maker Innolux has unveiled a new 55" rollable mini-LED display prototype. This is an emissive mini-LED display, it is not a mini-LED backlit LCD display:

Innolux did not disclose any specifications on this display (not even the resolution), but it did say that the display use a flexible PCB and features "high curvature, high brightness, high contrast, high saturation and high definition dynamic picture".

AU Optronics released this nice video that shows its latest microLED display prototypes. First up is the company's 12.1" automotive display. This one features a 1920x720 (169 PPI) resolution, and is made on an LTPS backplane. This display was shown first in 2018.

The second display in the video is the flexible microLED developed in collaboration with PlayNitride. This is a 9.4" 228 PPI display, again driven by an LTPS backplane.

PlayNitride introduced several new display technologies at SID DisplayWeek 2020. First up we have the PixeLED Matrix, which is a tiled microLED display module based display, each produced on its own PCB.

Each PixeLED module is made from 16 pixels (4X4), and can reach pitches of 0.3-0.4 mm. PlayNitride says that this technology can compete with mini LED displays, and says that it achieves a superior contrast and can also be fitted on curved surfaces. PixeLED displays can be used for TV displays, for commercial signage displays and also for automotive lighting. The display can currently achieve a maximum brightness of 2,000 nits.

Researchers from the University of Waterloo in Canada developed a new transfer and bonding method to deposit a flexible microLED array on plastic substrates.

The technique, referred to as a "paste-and-cut", starts with temporarily bonding the LEDs on a process/handle wafer onto a glass substrate (the paste step). The LEDs are then released (cut) to the flexible substrate. This approach allows the LED to be optimized and then combined with other materials.

AU Optronics and PlayNitride announced that the two companies have developed a 9.4" 228 PPI flexible microLED display. The new display is driven by an LTPS backplane and the two companies say it delivers a large color gamut, is weather resistance and it is suitable for automotive applications.

AUO and PlayNitride has been collaborating on microLED display technologies for many years. In early 2019, AUO announce it plans to accelerate its development of Micro-LED products. The company previous prototype was a 12.1" 1920x720 (169 PPI) panel. In September 2019 AUO's president said that he expects Micro-LED displays to enter the market within 1-2 years, starting with large-area signage and small-sized VR displays.

iBeam Materials announced that it had successfully demonstrated the ability to produce high-performance GaN Field-Effect Transistors (FETs) directly on thin, flexible and rollable metal foil substrates.

This new technology complements iBeam's microLED deposition technology (demonstrated in the video above), and these FETs can be integrated with microLED chips in a side-by-side architecture. Both FETs and MicroLEDs are deposited on the flexible substrate without any transfer process.

In May 2019 PMOLED display maker RiTDisplay announced a strategic partnership and share swap with MicroLED developer PlayNitride, and RiT later said it aims to release its first product to the market in 2020.

RiT announced today that its revenues for the year (to date) were $47.1 million USD - a decrease of 32.4% compared to last year. The company's CEO says that its PMOLED sales has been affected by e-cigarette bans in the US, and the company is now shifting its focus to develop micro LED displays (and also mini-LED ones).

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.

iBeam Materials announced that it has received an investment from Samsung Ventures. iBeam developed a technology that can be used to produce LED chips on large-area flexible foils.

iBeam Materials, founded in 2011 in the US, is still at an early stage but this technology could enable the production of micro-LED devices directly on large-area flexible substrates without the use of a transfer (pick-and-place) process.