OLED ink jet printing: introduction and market status - Page 22

Merck has signed a cooperation and licensing agreement with Seiko Epson. According to the agreement, Epson will supply Merck with ink technology that dissolves Merck's soluble OLED materials so that they can be used for the production of printable OLED displays. This brings Merck closer to providing production-ready OLED printing materials.

The two companies will also continue their close cooperation to create a strong ink-formulation roadmap in order for Merck to commercialize and address current and future requirements of the OLED TV industry, including the creation of industry-standard inks for manufacturing OLED TVs using inkjet technology.

German startup Cynora unveiled a new mostly-solution-based flexible OLED prototype - aimed for smart packaging applications. Cynora developed the low-cost emitters (based on copper precursors) and developed the prototype in collaboration with InnovationLab (in a project titled cyFlex).

Cynora are now working towards the integration of the wiring into the thin film layers of the OLED. Cynora are using solution processing (coating and printing).

Digitimes reports that AUO has started to develop a printing process to make OLED panels, with hopes that this new process will lower the production cost and increase the material utilization. AUO is suffering from low (50%) yields in its current production process - which uses vapor deposition. The report suggests that AUO is also developing Oxide-TFT backplanes for OLEDs - but this isn't news - AUO unveiled an Oxide-TFT based 32" OLED TV prototype back in November 2011.

Actually all OLED makers are looking into more efficient production processes based on printing so this is hardly a surprise. It's likely that it will take some years before we'll start seeing printed OLED panels on the market though.

According to a report from Nihon Keizai, Panasonic has taken steps to streamline its R&D and put more focus on OLED TV development. The company plans to invest ¥30 billion ($385 million) in a pilot AMOLED production line in Himeji (this was already reported in April). According to the report Panasonic wants to use PLEDs and ink-jet printing in its upcoming fab. Panasonic's P-OLED/Ink-jet development dates back to the OLED TV joint-venture with Sumitomo in 2009.

Sony OLED TV prototype

The report also details the collaboration between Panasonic and Sony. The two companies have quite different technologies - Panasonic with its P-OLED and printing processes and Sony with small-molecules and VTE. It is claimed that Sony will mostly supply capital for Panasonic, and not technology. Sony's own OLED technology will be used though by Japan Display to make small sized panels.

Researchers from the Fontys University in The Netherlands have demonstrated that patterned plasma treatment of substrates gives them better control over inkjet printed structures (which results in higher quality printing).

The researches have used tailored wettability using InnoPhysics uPlasmaPrint technology that can locally change surfaces from hydrophilic to hydrophobic and vice-versa, creating patterns that make droplets spread in only one direction while restraining them in the other direction. Printed lines created in this way have both a very high homogeneity and a well-controlled width (without this technology the inkjet spreads in all directions which creates broader lines). In the research they used PixDro's LP-50 R&D inkjet printing platform.

Merck is a global pharmaceutical and chemical company based in Germany, working on high performance OLED materials. We're happy to post this third interview with Merck's OLED unit VP, Dr. Udo Heider:

Q: Dr. Heider, thanks for taking the time to do yet another interview with us.

Thanks Ron. I do appreciate this opportunity to communicate about our recent Merck OLED activities.

I'm assuming that Merck is still focused on Solution Processable materials. Can you give us a short update on the current status of your materials?

Yes, of course, we are very diligently focused on solution processable materials development based on our customers requests. As communicated in the past, Merck is working on solution processable small molecule materials. Our chemists have devised ways to redesign an evaporable small molecule and optimize its performance within a soluble device stack, applicable to the various soluble "printing" process windows.

The Holst Centre and Solvay report advances in flexible OLED lighting panels. They present a bendable 69 cm² OLED panel that features 30 lm/W efficiency at 1000 cd/m²:

Konica Minolta has successfully developed a high-accuracy inkjet head capable of 1-picoliter drop size, the first for printed electronics applications. The new print head utlilizes the company's proprietary MEMS technologies for the first time. KM will start offering the new inkjet printhead (the KM128SNG-MB) in sample quantities by this spring.

The new print head is resistant to various inks required for industrial applications and suitable to use with low-viscosity inks. It can be used for all sorts of applications, including OLED display patterning and OLED lighting thin air coating.

Tanaka Kikinzoku Kogyo announced that their conductive silver ink is now available commercially, and they say they are the first company to offer such a prOduct. The silver ink is hardened using UV light - there's no need for thermal hardening, and can be used in a broad range of products - including OLED panels.

The ink needs to be exposed to UV light for around 0.3 seconds, and it then hardens instantaneously even at room temperature to form a current-carrying circuit. For a 5 µm film thickness, wiring was formed with an electric resistivity of 10^-3 ohm cm. The ink can be used on both a glass base and a flexible base (PVC or PET films).

The Holst Centre and imec announced a new high-resolution flexible OLED displays research program. This new program builds on the existing research fields such Organic and Oxide Transistors and Flexible OLED lighting. The new program aims to develop an economically scalable route to flexible AMOLED mass production, facing challenges such as high resolution, low power consumption, large area, outdoor readability, flexibility and light weight.

The partners will develop a mechanically flexible encapsulation film and TFT backplane, a printed high-efficiency OLED, new materials and processes that will allow cheaper production at better quality and driver design. They will also develop a new manufacturing equipment such as fine patterning equipment for backplanes and tools for integrated roll-to-roll manufacturing. This new program follows up on the FLAME project. Above you can see a prototype Polymer-Vision made flexible OLED made together with imec and the Holst Center.