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.

PlayNitride demonstrated its latest Micro-LED displays at SID DisplayWeek 2019, and the following recently-published video shows the company's booth and prototypes:

So first up we have a 7.56" 720x480 (114 PPI) transparent MicroLED display, which looks very impressive. This is the same Micro-LED display that TianMa demonstrated at its own booth. Interestingly, under direct light from it seems that the display is made from tiles - but PlayNitride says that the squares are made from the stamping process, and the company is developing technology that will remove these marks.

Researchers from the University of Waterloo have demonstrated the successful integration of a-Si:H TFTs and high-efficiency micro-LED chips on large-area flexible substrates. This is the first time that an amorphous silicon was used to drive Micro-LEDs which could pave the way for lower-cost micro-LED display fabrication using existing LCD technology.

the researchers use a 2-TFT pixel circuit, with blue GaN-based micro-LED chips. The low-temperature TFT production process enabled the direct integration onto a flexible flexible polyethylene naphthalate (PEN) substrate. After the TFT fabrication, the micro-LED chips were flip-chip bonded on the TFT, and then transferred onto the flexible pixel circuit using a selective laser lift-off process.

US-based Rohinni announced a new joint-venture with Magna Electronics to develop flexible mini-LED and micro-LED based lighting devices for the automotive market.

The new JV, controlled by Magna Electronics will be called Magna Rohinni Automotive Electronics and will be based in Holly, Michagan, US. In addition to the JV, Magna also made a minority equity investment in Rohinni.

Researchers from Korea's KAIST developed flexible vertical micro-LEDs (f-VLEDs) using anisotropic conductive film (ACF)-based transfer and interconnection technology.

The researchers developed their own transfer equipment and used it to fabricate a 50x50 array of f-VLEDs using simultaneous transfer and interconnection through the precise alignment of ACF bonding process. The researchers report that the micro-LEDs achieved an optical power density of 30 mW/mm2 - which is three times higher than that of lateral micro LEDs. The LEDs offer improving thermal reliability and lifetime by reducing heat generation within the thin film LEDs.

Digitimes posted an interesting research note, in which they state that micro-LED displays may find it hard to compete with LCD and OLED displays as the market is approaching saturation.

Micro-LEDs have several advantages over other displays - high brightness, quick response time and the ability to create flexible and transparent displays (this is also true for OLEDs). However a major advantage for Micro LEDs is that the aperture ratio is only 10%, which means that there is a lot of empty space in a micro-LED display.