OLED (Organic Light Emitting Diodes) is a flat light emitting technology, made by placing a series of organic thin films (usually carbon based) between two conductors. When an electrical current is applied, light is emitted. OLEDs can be used to make displays and lighting, with possible applications that span TV sets, computer screens, mobile phones, decorative lighting and more. Since OLEDs emit light they do not require a backlight and so they are thinner than LCD displays, and are also more efficient, simpler to make and boast a better color contrast.
While OLED displays excel in color-contrast and efficiency compared to LCDs, they’ve also proven relatively hard to produce on a large scale. Current evaporation-based production techniques involve a lot of wasted material and risk of defects. OLEDs are also extremely sensitive to moisture and oxygen and therefore must be protected with a high performance encapsulating layer. All of these issues hinder OLEDs’ market takeover, but much work is put into resolving them.
OLED ink-jet printing
Current OLED producing methods rely on evaporation processes, in which the organic materials are deposited onto a glass sheet through a thin metal stencil, also known as a "shadow mask”. This process is problematic, as a significant amount of the material is wasted because it disperses all over the mask, in addition to inherent mask changes which expose the sheet to dust and compromise yields (OLEDs are by nature sensitive to contamination).
Inkjet OLED printing has the desirable ability to allow precision deposits without the use of a mask. It also produces less stray particles, thus boosting yields. These significant advantages make this technology interesting to many companies and virtually all OLED makers have active ink-jet printing development projects.
Inkjet methods form films by discharging the required amount of organic material onto large glass substrates in regular atmospheric conditions. This could be done, for example, by placing OLED pixels on glass or plastic using a portable platform and nozzles. Such methods have the potential to increase yields and lower prices, thus enabling OLED technology to take its deserving place in the market.
Unfortunately, OLED inkjet printing is not yet common, as printing OLED displays is a relatively challenging task for many reasons. A number of layers need to be deposited in pixels (the size of the pixels themselves is defined by the overall resolution the display will have). Being able to place the right number of drops of the active materials into the pixels is a challenge, in addition to developing a process in which the ink dries to deliver flat films of materials in the pixel.
Despite major progress, it is maintained that soluble OLED materials (required for inkjet printing) are less effective than evaporable ones. Ink-Jet printing is also not able to reach the same high densities of evaporation OLED production, which limits its applications for large-area production (TV panels) and not small mobile, VR and wearable OLEDs.
Ink Jet printing is still not used in any commercial OLED display production. But progress in past years have been rapid and some believe that initial OLED TV production using ink jet printing may begin in 1-2 years.
The latest OLED ink jet news:
Samsung Display is developing hybrid QD-OLED TV technology, and according to estimates, the company aims to begin trial production in 2019. It is also estimated that Samsung has several challenges to overcome, but according to new reports from Digitimes, Samsung is aiming to start installing equipment for the new fab as early as December 2018.
The new fab will begin operation in the second half of 2019 - pilot production at first which will be expanded to full scale mass production. The new fab will be built in Samsung's L8 LCD production line in Asan, and will take over one of the two lines currently in operation at the fab. Samsung's initial production capacity will be around 25,000 monthly G8 substrates.
AUO to establish an OLED ink-jet production line, to make OLEDs for monitors and automotive applications
According to reports from China, Taiwan-based AU Optronics decided to establish an inkjet OLED production line that will be used to produce OLED monitor displays and OLEDs for automotive applications.
The new OLED line will use production equipment made by Japan's JOLED - who started commercial low-volume production of its own 21.6" 4K OLED panels, at the company's pilot 4.5-Gen line. JOLED also announced plans for a mass production 5.5-Gen line that will be established in Nomi City, Ishikawa Prefecture, by 2020, and similarly to AUO, it is focusing on monitors and automotive applications.
The EU-funded Flexolighting project believes that OLED lighting cost can be reduced to 1 Euro per 100 lumens
In 2015, the EU launched the €4.4 million Flexolighting project (led by Brunel University London) with an aim to develop new materials, processes and methods to overcome current OLED lighting challenges - including lifetime, lighting uniformity and more.
The project's consortium announced that following the project completion and a rethinking of the complete OLED supply chain, it believes that high efficiency OLED lighting panels can be produced at a cost that is on a similar level with LED lighting.
JOLED announced today that it signed an agreement with Screen Finetech Solutions and Panasonic Production Engineering to co-develop, manufacture and sale printing equipment for large-area OLED production (mostly OLED TVs).
The three companies aim to quickly commercialize a new business that will be based on JOLED's manufacturing technology. JOLED plans to license its inkjet printing technology to OLED makers. JOLED has been developing its technology in collaboration with Panasonic since its founding in 2015. JOLED's technology was originally developed in Panasonic at around 2006.
JOLED raises $400 million - half of what it needs to establish its first printed OLED mass production line
Last month Japan-based OLED maker JOLED announced official plans for its first mass production printed OLED fab, and today it is reported that JOLED have raised around $400 million from four new investors - auto parts maker Denso ($270 million), major trading house Toyota Tsusho ($90 million) and Sumitomo Chemical and Screen Holdings.
JOLED intends to raise $900 million, so the current amount is less than half of what it needs to complete its first mass production line. According to earlier reports, Panasonic and Sony also intend to to invest around $50 million each.
Towards the end of 2017, JOLED started commercial production of its 21.6" 4K OLED panels. But this is very low volume production (at JOLED's pilot 4.5-Gen line) as the company said it is seeking to raise $900 million to support its plan to start mass producing OLEDs in 2019.
Today JOLED announced official plans for its first mass production printed OLED fab. JOLED will establish the production site in Nomi City, Ishikawa Prefecture. The capacity of the new fab will be 20,000 monthly 5.5-Gen (1300x1500 mm) substrates and the plan is to begin mass production in 2020. JOLED will produce 10- to 32-inch OLED displays for automotive displays, high-end monitors and more.
In February 2018 it was first reported that Samsung Display is developing TV panels based on hybrid quantum-dots and OLED architecture (QD-OLED). Samsung later confirmed it is developing such technology, but with no immediate plans to commercialize it.
ETNews now reports that Samsung is now working to establish a pilot 8-Gen line for QD-OLED production. ETNews says that Samsung is collaborating with both Canon Tokki and Kateeva to develop the production equipment - apparently the OLED layers will be evaporated using Canon's machines while the QD filters will be deposited using ink-jet printing equipment made by Kateeva. Samsung aims to finalize the production line by the second half of 2019.
CSoT details its OLED ink-jet printing plans, collaborates with Kateeva, Sumitomo, Merck, DuPont and Tianma
Last month CSoT (TCL) announced plans to establish a 11-Gen LCD+OLED TV fab in Shenzhen, China. Details on the OLED part of that fab were not given, but now we have some updates following the company's investor day.
The new fab will use Oxide-TFT backplanes, and it turns out that the OLED part of the fab will also use the 11-Gen substrates (which may be cut for the actual OLED front plane deposition). Out of the entire capacity of 90,000 monthly substrates, the OLED line will use 20,000 substrates. The fab will start mass production in 2021.
China's largest display maker BOE Display has an active OLED ink-jet printing project, and according to reports the company is establishing an R&D production line (in Hefei) that uses Kateeva's inkjet deposition equipment.
At SID 2018, BOE demonstrated a printed OLED panel for the first time. Surprisingly this is a small mobile OLED display - a 5.5" FHD (400 PPI) flexible AMOLED. It is usually assumed that inkjet printing is limited to around 200 PPI, and so only useful to large area panels (such as TVs or monitors). JOLED's 21.6" 4K printed OLEDs have a PPI of 204, for example. In 2017 Korea-based Unijet's president said that Inkjet printing could reach up to 550 PPI in 2020 by using next-generation laser-droplet technologies.
Pixelligent raised $7.6 million, is working with Kateeva to adopt its materials for OLED inkjet printing
US-based high-index material maker Pixelligent Technologies announced it raised $7.6 million in a new funding round that will help the company to further drive its product commercialization and accelerate global customer adoption.
This round was led by the Abell Foundation, and included other Baltimore-based investors. This found also included strategic investments from Kateeva and Japan-based advanced material producer Tokyo Ohka Kogyo.