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 are used to make displays and lighting panels. OLEDs today are widely used in TVs, smartphones, tablets, laptops and wearables.
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.
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.
For many years, companies all over the world invested heavily in inkjet printing processes for OLED displays, but the process is not yet common, as printing OLED displays is a relatively challenging task, and soluble OLED materials 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.
Printed OLED panels on the market
One area in which inkjet printing is common in the OLED production process is the encapsulation layer deposition. Almost all OLEDs that adopt TFE encapsulation use inkjet printing to deposit the organic elements.
LG 32EP950 OLED monitor (31" 4K printed OLED panel by JOLED)
For actual OLED emitter layers deposition, currently the only company that commercially uses ink-jet printing is Japan's JOLED, who in 2021 started printing OLED display panels in its 5.5-Gen production line in Nomi, Ishikawa Prefecture, Japan.
The latest OLED ink jet news:
Join us next week for a 2-day OLED innovations virtual event, as part of MicroLED-Connect!
MicroLED Connect, our hybrid event series focusing on the microLED industry, will be hosting a two-day virtual event focused on the OLED innovations, technologies, manufacturing, markets and more. The online event will take place next week, on April 10-11, and will be an excellent opportunity to learn the latest OLED updates and connect with industry professionals on our excellent online event platform.
Today we have published the agenda for this event, with 20 exciting talks by leading OLED developers, supply chain companies and top-edge researchers. This will be an excellent opportunity to learn and connect with the OLED industry. You can register for the event here, with a yearly pass to MicroLED-Connect (with an option to also include entry into our September on-site event in Eindhoven, The Netherlands). Our members also gain access to past event recordings.
Inuru inaugurates its inkjet printing OLED lighting production line in Wildau
Germany-based OLED lighting developer Inuru inaugurated its new OLED lighting panel production line, the "Dragon Factory", in Wildau near Berlin, Germany. This is an important milestone for Inuru, which is focusing on medication packaging and entertainment applications. The production line is now ready, but it will probably take some time to ramp-up and achieve full-scale production.
Inuru produces its OLED lighting panels using an inkjet printing process, which it says educes production costs by around 90% compared to conventional (evaporation-based) processes.
TCL CSoT showcases transparent, flexible and inkjet printed OLED displays at CES 2024
TCL CSoT demonstrated several OLED displays at CES 2024. first up we have an automotive 10.1” transparent OLED display, that offers 52% transparency. CSoT says that this is a "Smart Transparent" display, although it's not clear what is meant by that exactly.
The second display is a 14" 2.8K (2880x1800, 240 PPI) inkjet printed hybrid OLED. This is the first time that CSoT has printed a laptop AMOLED display. It uses an IGZO (Oxide-TFT) backplane, and offer a variable refresh rate (30-120Hz) to expand the battery life. This display was first shown last month, when TCL stated it is on track to start mass producing OLEDs using an inkjet printing process in the second half of 2024.
IPValue buys 200 OLED patents from Seiko Epson
IPValue Management announced that it has acquired around 200 OLED patents from Seiko Epson. We do not know the nature of these patents, and whether IPValue bought all of Seiko Epson's OLED IP portfolio or just a part of it. IPValue says that the patents will be owned by its subsidiary Lumitek Display Technology.
Seiko Epson has been working on OLED technologies for many years - and it has been involved mostly with soluble OLED materials, ink-jet printing and OLED microdisplays. In 2013 Samsung Display bought several OLED patents from Seiko Epson.
TCL CSoT reiterates plans to start producing inkjet printing OLEDs in 2024, to target IT displays
TCL CSoT says that it will start producing OLED displays using an inkjet printing process in the second half of 2024. This is excellent news and good to know CSoT is still on track for initial production in 2024. The company says it will first target the IT and medical sector.
The company says that the cost of producing OLEDs using its inkjet printed panels will be lower compared to the currently-used FMM based method, and its OLEDs will offer superior performance (in lifetime, mostly) as its process enables higher aperture.
Reports suggest Kateeva's printers failed Samsung's QD printing tests, will not be used for QD-OLED production
According to reports, Kateeva's QD-OLED printing project saga is not over. Samsung Display tested the company's latest printers, but these failed the tests and Samsung Display will not but these printers. SDC planned to replace the currently-used Semes' printers, which also suffer from low performance.
Samsung Display is also not committed yet to expand its QD-OLED production lines, which means that in any case it does not need to buy new printers for production expansion. Earlier reports suggested that SDC wanted to upgrade it current capability for higher density (to reach 8K TV printing), so this may be the reason behind the testing of Kateeva's new printers.
A senior researcher formerly working at Samsung Display, accused of stealing OLED trade secrets with an aim to sell them to Chinese display makers, returns to Korea to face chargers
In 2021, we reported that two researchers working at Samsung Display were convicted of handing over OLED technology to other companies, and are being sent to prison for two years. Representative and directors of the company that bought the technology was also sent to prison and the company was fined. The technology in question relates to Optical Adhesive Materials used in OLED production processes. The arrest of these employees was reported earlier in 2020.
It is now reported that another employee of Samsung Display, also involved in that case (seems to be he was the main organizer of the outfit) fled Korea following his indictment, but has now returned voluntarily to Korea and has been arrested and is now bring charged with violating unfair competition laws in Korea.
CSoT is planning to buy JOLED's inkjet printing production equipment and initiate production in China
Inkjet printing pioneer JOLED has filed for bankruptcy, following many years of struggles to increase production capacity and revenues. According to earlier reports from Japan, display maker Japan Display will take over JOLED technology and remaining operations.
There are now reports from Korea that suggest that TCL's CSoT is considering buying JOLED's OLED production equipment, and moving it to China to attempt OLED production in-house using inkjet printing. If this plan goes through, the plan is to initiate production in 2024. It's not clear whether CSoT is in talks with JDI, or whether JDI did not take over the equipment from JOLED.
Notion Systems – interview on EHD printing in the display industry
Notion Systems, a leader in ink jet printing for industrial applications, has been active in the display market for a long time. The company is now promoting its EHD technology for high precision printing. Here’s an interview we conducted with Antonio Schmidt – SVP Sales & Business Development and Jochen Seeser – Senior Process Development Manager, Notion Systems.
Hello Antonio and Jochen, thank you for your time. In 2022, you started offering EHD printing systems. Can you explain how this technology works and what applications does it enable in the display industry?
Notion Systems has been active in the display market since 2016, when we delivered an n.jet display for pixel printing to a lab of a leading display manufacturer in China. Since then, we have supplied several inkjet displays for RGB printing and encapsulation to various R&D and production sites in China and Taiwan. I think we can also claim that we are the only manufacturer, along with perhaps one other U.S. competitor, that has multiple systems in operation for 24x7 display production.
JDI announced it will acquire JOLED IP and some of its employees, but will not acquire its production facilities and technology
A few months ago we reported that Japan-based inkjet printing OLED developer JOLED has filed for bankruptcy, and that Japan Display (JDI) will take over JOLED's technology and operations. JDI released an official statement regarding JOLED and its plans for the future.
So indeed on March 7 2023, JDI signed a basic agreement to support JOLED. Since then the two companies held 'extensive discussions', following which JDI decided to form a subsidiary company called 'JDI Design and Development' or JDIDD, that will acquire JOLED’s OLED technology development business and all related operations.
