There are seemingly limitless opportunities for flexible printed electronics (PE). Sometimes it seems that the biggest hold-up is developing the manufacturing processes to make the systems. There are numerous equipment manufacturers who have built excellent systems, but integrating these machines is taking time.

Interestingly, research institutes are among those leading the way in creating integrated production lines. For example, The Centre for Process Innovation (CPI), the UK’s National Centre for Printable Electronics, just installed its new large area pilot production line. CPI’s clients can now fabricate large area, flexible organic thin film transistor (OTFT) backplanes, which can be used for displays, logic and sensor applications (PV).

Jon Helliwell, director of printable electronics for CPI, said that the pilot production line offers a high resolution (4 micron) large area (Gen2=370x470mm) patterning capability using non-contact lithography for minimization of defects in the photolithography process, as well as a selection of toolsets for metallization, wet coating, wet etching, dry etching, critical dimension measurement and defect inspection, again at sizes up to Gen 2.

CPI is also working on roll-to-roll processing of high resolution patterned devices on plastic, incorporating additive manufacturing processes such as printing.

“This line will be used to make flexible display backplanes e.g. flexible AMOLED displays, as well as other devices on plastic such as sensor arrays and logic devices,”  Helliwell added.

Helliwell noted that the line will have the ability to produce foldable and rollable displays.

“This will allow CPI to demonstrate high quality displays on plastic, and therefore show that OTFT can be processed in such a way to give high performance displays which can be rolled or perhaps even folded – something that display manufacturers are seeking for future display products,” Helliwell said.

CPI has been interested in the PE field for many years. In April 2012, CPI opened its Integrated Smart Systems (ISS) facility, a £2 million ($3.16 million) into its new facility. The ISS, which includes a Nilpeter press, has the capability to print flexo, gravure, offset litho and rotary screen printing processes alongside cut/crease operations and pick and place technology. Considering the capabilities of CPI’s newest pilot line, it comes as no surprise that the new pilot line is drawing attention from potential customers.

“We have numerous enquiries about the facility and how people can access the service, either directly or through our team,” Helliwell said. “Many SMEs in the UK are understandably looking to source experience and capability in order to make their finite financial resources deliver the quickest route to market. We will help them wherever possible to achieve this using the prototyping assets in CPI.

“Additionally, we are getting traction with universities and their collaborators to move projects up the TRL scale, mainly related to scale-up, resolving technical issues, demonstrator construction and collaborative project building,” Helliwell added. “We are looking to build on these interactions, where CPI acts as the hub for universities to bring their ideas to us and help them progress to commercialization, strengthening their position and speeding up the delivery.”

For example, CPI is currently involved in a number of UK and pan European collaborative projects.

“Europe’s leading organic and large-area electronics organizations have united to form COLAE – Commercialization Clusters of Organic and Large Area Electronics – a project designed to simplify and speed up the commercialization and adoption of OLAE technology through the creation of industry clusters,”  Helliwell noted. “Another European collaborative project which CPI is a partner of is Diginova. The project consortium, consisting of four large companies, seven SMEs (small and medium enterprises) and nine research institutes and academia, aims at transforming EU industries from their analog roots to their digital future by identifying the most promising technology and business propositions for digital fabrication.”

CPI is also involved in a number of commercial projects. One of which is with Peratech, who are using CPI’s ink facilities to work on new ink formulations for pressure sensitive switches and sensors. Another is PragmatIC Printing Limited, who are utilizing CPI’s pilot scale production facilties for their printed logic circuits that introduce intelligence and interactivity into a wide range of products and applications, in form factors that are not possible using silicon chips.

In the area of clear barrier and encapsulation, Helliwell reported that CPI is currently involved in four EU-based collaborative projects that include research institutes, SMEs and large multinationals. In addition, CPI is also working on a number of commercial projects with UK-based companies. Work varies from small scale to 0.5m roll to roll production (using ALD and sputter technologies), with total project values accounting to up to more than £20m in the next three years, with £2.5m direct support towards CPI.

OLED is another area of interest for CPI.

“In regards to our OLED lighting capabilities, collaborative programs Flexibilis and HiPBE will utilize CPI’s pilot production equipment to produce prototypes for the characterization and development of high performance barrier layers,” Helliwell said. “CPI’s technology roadmap is targeted at further advancing the development of flexible optoelectronic devices and on continuing to address many of the challenges required in scaling up this emerging technology to commercialization. Our OLED capability will also be used in projects to support demonstration of ultra-flexible active matrix (AM) OLED using CPI’s organic transistor technology.”

Helliwell said that the ability to demonstrate controlled processes that can yield products with good lifetime and performance is essential for the future of PE.

“This takes more time and resource than many people estimate, therefore it is important that both the technical and financial plans are well structured and realistic,” Helliwell said. “In terms of technologies, we envisage flexible displays (with some printing involved such as slot die coating) to remain an important development target; some types of photovoltaics (e.g. solid state dye sensitized cells and other thin film flexible devices) are looking particularly promising; and then slightly further out, bio or chemical sensors on plastic, which may involve inkjet printing of molecules.

“Across many application areas, the development of low cost, high performance barrier coatings is a key requirement,” Helliwell added. “We envisage that R2R ALD will play important roles in various aspects of flexible ‘printable electronics,’ where highly conformal nanoscale thin films are required. CPI recently signed an agreement with Beneq to deliver a roll-to-roll (R2R) ALD system that operates at pilot production scale. The unit, WCS 500, is capable of coating 500 mm wide webs. We certainly believe the future is bright for R2R ALD applications and have recently bolstered our barrier team, which enhances CPI as a forerunner in the development of ALD-based flexible thin-film moisture barrier technology for demanding flexible electronics applications.

Helliwell said that PE has the potential to develop in many different fields, and he believes there are new possibilities that are not yet apparent.

“CPI has a range of equipment sets to help develop printed electronics applications, and we do not want to discourage people from exploring their own ideas for products.”  Helliwell concluded. “After all, the UK has the capability to innovate in many different fields, so it will not be surprising if new commercial applications come from sectors that we have not yet identified.”