With equipment in the clean room, it is a good time for Steve Bush to find out more about the UK's printed electronics centre.
The Printable Electronics Technology Centre (Petec) in County Durham has been built make printable plastic electronics intellectual property ready for production.
"We have set ourselves up to fill the gap between innovation and mass production," Petec director Tom Taylor told Electronics Weekly. "We have a business model approach - we do a lot of technical things, but we are not a technology company."
Built on a green field site in Sedgefield, the centre has a large clean room that is being fitted with plastic electronics manufacturing equipment. There is also space reserved for the OLED lighting production line of PolyPhotonix and the organic solar cell line of an as yet un-named customer.
"The clean room is a third full and we have two thirds of the team, which is fully stretched commissioning the equipment and doing existing work," said Taylor.
Business
Although not primarily a technology company, Petec has grown out of, and is part of, the Centre for Process Innovation (CPI) in Wilton, North Yorkshire.
Through CPI, Petec has access to polymer coating, oxide coating, and polymer transistor array technology, including polymer transistors faster than amorphous silicon devices.
"We tend only to pull in technology to solve a particular problem," said Taylor, "but we have developed a lot of knowledge ourselves in three years at Wilton and have filed and developed some of our own IP in semiconductor materials processing."
Until Petec's Sedgefield equipment is commissioned, the Wilton lab remains its primary development centre.
£11m of UK and European money has been invested in the centre, whose operation will be self-funded through commercial contracts.
This model of government-funded build followed by commercial operation has been successful in Europe, notably with Belgium's huge IMEC semiconductor lab and the various Fraunhofer institutes in Germany.
IMEC, founded by the Flemish government in 1984, not only brings in tens of millions of Euros from funded research every year, mostly from industry giants, but has spun companies out into its local environment.
"We believe we are the first exponent of this model in the UK," said Taylor. "Attract companies into the region and we will get part of the action. It will be easier to incubate smaller companies if we have larger companies around."
Petec has to be self-sustaining, and it will work on projects three to five or more years from mass production.
"We have enough forward orders and cash in the bank to cover costs for the next 18 months to two years," said Taylor. "Keeping orders coming in is the business development challenge we face. From a sustainability point of view, we need to work with large companies. We have a Japanese office, for example."
At the moment "our customers are a small number of large companies, and a large number of small companies which do work within the EU Framework or on Technology Strategy Board projects", said Taylor. "And we do work for universities."
Projects come from a variety of sources. From organic materials companies that are too small to be able to prove their own technology, to large companies that want a quick appraisal of innovations they are considering investing in.
"In a typical project, someone in a university lab will make one transistor," said Taylor. "They don't have the skill set or the equipment to make an array. We do - using a variety of fabrication processes."
Petec has a team based in Wilton, making transistor arrays and working on processes for companies including some already in the polymer display business.
"Where we can be of help, is demonstrating how new materials and new processes can be bought together scalably for manufacture," said Taylor, who is realistic about the Centre's skill set. "For what we do, we believe we have got an edge. For other stuff, they can go elsewhere."
He classes the Petec equipment being installed, including some from the Atmel fab that closed on Teesside, as, "Important in a UK and European context. Large Asian and US companies have their own gear or could buy it."
That said, he points out that companies with their own equipment contract-out work when they are too busy, and not all companies want to build a lab just to try out one idea. "We have shown we can accelerate technology faster than they could internally and, or, at lower risk."
What Petec has is a world-class team, including former employees of German display chemical giant Merck, Samsung, and the Korea Electronics Technology Institute.
"The particular expertise we have is the result of a small number of people, probably half a dozen," said Taylor.
Transistors
The amorphous silicon thin-film transistors used in many active-matrix displays have carrier mobility somewhere near 1cm2/Vs. Taylor claims Petec printed polymer devices can beat this.
"I can't speak about the mobilities we have achieved here because the work has been done for specific customers. All I can say is that a number of materials are available to the industry where mobilities of 5-7cm2/Vs have been demonstrated," he said.
The key question, according to Taylor, is can these polymer materials be processes to produce repeatable, uniform, stable operation across an array.
"We are seeing lower average mobility, but comfortably exceeding the performance of amorphous silicon, on glass and flexible substrates adhered to glass."
Although roll-to-roll transistor printing is on the far horizon for Petec, all foreseeable future processing at Petec will be on panels, either glass or plastic substrates temporarily stiffened with glass.
Barriers
Barrier layers are needed to keep moisture and oxygen from diffusing through plastic substrates. Different types of plastic electronics demand different grades of barrier.
"We have processes and materials that I think are globally unique," said Taylor. "Most people have static set-ups. We have a set-up for continuous coating of barriers roll-to-roll."
He claims to have a barrier well-suited to general purpose displays, although not yet good enough for long-life OLED displays containing calcium electrodes.
However, Petec is handling one intended for the OLED gold-standard.
"One project we are doing with an overseas customer is a barrier of 10-6g/m2/day they invented," said Taylor. "We have tested and confirmed this figure and are working with them to scale."
The in-house barrier also shows promise.
"We have shown we can do economical barriers at low performance," said Taylor. "I think I have seen enough to be confident we have a way to get to OLEDs."
There is already a commercial coating that can hit the magic 10-6, according to Taylor, but the Vitex process is expensive. "People are working on varieties of that, and people are working on alternatives to calcium that may not need 10-6."