Roll-to-roll - Page 6

Nanomarkets posted an interesting article on flexible glass (based on their Flexible Glass Market report). Basically they're saying that the opportunities for flexible glass have never been better, and they forecast that the market in 2013 will reach $125 million, and this will grow to over $2 billion before 2020.

Interestingly Nanomarkets says that the OLED market will start adopting flexible glass in 2013 - with $4 million in revenue (this will grow to $280 million by 2020). Perhaps Nanomarket thinks that Samsung will adopt flexible glass in their first YOUM flexible OLED based panels?

ITRI announced it has developed a full roll-to-roll process on 100um flexible glass substrates - they say they're the first in the world to do so. ITRI has been collaborating with Corning on this technology, and they are using Corning's flexible Willow glass, unveiled at SID 2012.

ITRI and Corning developed specially designed R2R machines that produce touch panel modules on Corning Willow Glass, a flexible display-grade glass substrate. ITRI are now looking for companies that sell this technology - which can be used for OLED display and lighting panels, solar panels and more applications.

One of the promises of OLED lighting is that flexible panels can be produced on the cheap using roll-to-roll processes. There is a lot of work towards this goal, but it hasn't been achieved yet. Now researchers from Sweden and Denmark have managed to produce light-emitting electrochemical cells (LEC) using an all-solution-based R2R fabrication process, in ambient conditions. They say that this process can be used to create large area panels too.

Polymer LEC panels are similar to PLEDs in structure, but in LECs the emitter polymer is blended with an electrolyte (e.g. LiCF₃SO₃ dissolved in PEO). LECs, which require only three layers, were first reported 15 years ago, but they suffered from very low lifetime and efficiency. But LECs are very easy to produce and so with steady improvements (mostly from choice of electrodes) LECs are now ready to enter the lighting market.

COMEDD published an interesting article detailing their current R2R research line. The vacuum deposition and fabrication of small-molecule OLEDs is made in the RC 300-MB roll-to-roll vacuum coater (supplied by Von Ardenne Anlagentechnik). This machine is capable of processing metal and plastic substrates (300 mm width). The article also details the encapsulation, inspection and defect-detection processes.

COMEDD (Center for Organic Materials and Electronic Devices) is now an independent Fraunhofer institute (it was established as a department in at the Fraunhofer IPMS originally). COMEDD's aim is to carry out customer R&D and pilot fabrication of vacuum-processed organic materials applications.

Rolith says they are developing a new proprietary nanolithography technology that uses its "Rolling Mask" lithography system (RML). Rolith says that the new technology will enable low cost, high throughput and large area nanopatterning, and is suitable for OLED panels. In fact the company is seeking collaboration with companies - to jointly develop this technology.

Rolith's technology is based on a novel concept of continuous (conveyor, or Roll-to-Roll) nano patterning using cylindrical photomasks. A prototype was designed and built in 2011 in partnership with SUSS Microtec which allows patterning a 300 mm x 300 mm plates or 12 wafers. Rolith has successfully demonstrated printing dense nanostructures with less than 300 nm features, and are currently working on enhancing the resolution. The company's roadmap promises scaling up to 1m substrates in 2012 and up to 3 meters in the next 2 years. They are also developing a technology that will handle flexible substrates.

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.

Researchers from Dresden's University of Technology (TU Dresden) developed new highly efficient white top-emitting OLED design that feature "outstanding" color quality, and is compatible with flexible OLEDs. In this new design a refractive index matched microlens film was laminated to the top-emitting OLED to form direct optical contact. This enabled the researchers to achieve a CRI of 93, CIE coordinates of (0.472, 0.430) and an emission from 410 to 750 nm that almost spans the complete visible spectrum (380 to 780 nm). The efficiency is up to 30 lm/W (on par with the latest record white OLEDs from Novaled and OSRAM).

The lamination of such an outcoupling structure should be fully roll-to-roll compatible and even allows to be used as an encapsulation film when water and oxygen barriers are added.

Aneeve Nanotechnologies, a startup company at UCLA's on-campus technology incubator, managed to fabricate a new fully ink-jet printed carbon nanotube (CNT) circuit that is used to drive OLED displays. The company says that this is the first practical demonstration of carbon nanotubebased printed circuits for display backplane applications, and it shows significant performance advantages over traditional organic-based printed electronics.

Aneeve says that this shows that CNT is a viable technology to compete with a-Si and metal-oxide semiconductor for low-cost and scalable backplanes.

The Fraunhofer IPMS are developing a roll-to-roll process to make flexible large area OLED lighting panels. Next week they will show a 30cm wide flexible OLED lighting panel on a metal foil, fabricated at COMEDD. In fact they say that this demonstrates that they developed all necessary process steps for a complete production of flexible OLEDs in a roll-to-roll tool: from the structuring of substrate up to the lamination of barrier foils.

HP has developed a new method to produce large AMOLED panels, based on roll-to-roll manufacturing. They say that one of the biggest challenges to make flexible OLEDs is the alignment on large area flexible substrates. The new solution uses self-aligned imprint lithography (SAIL) to laminate a well-defined micro OLED (µOLED) frontplane unto a flexible active matrix amorphous silicon TFT backplane.

SAIL process flow

HP says they already built a proof-of-concept AMOLED device - which contains a flexible µOLED frontplane with OLED sizes of 50 µm on PET and active matrix backplane on polyimide with pixel pitches of 1 mm. The company claims that the new method will enable large area OLEDs at a very low cost.