As a significant portion of the display world gears up for SID’s Display Week 2008 in Los Angeles next week, editors and analysts are being inundated by press releases, some promoting the trivial and some announcing the truly significant.

Ken Werner
Senior Analyst and Editor

Among the significant announcements are two related to large-panel AMOLED displays, and there are other OLED-related announcements fueled by the fact that we have finally entered a genuine OLED ramp-up - not only a ramp-up in manufacturing capacity for mobile-handset displays, but also a ramp-up in preparations for larger sizes and a wider range of applications.

One of AMOLEDs big hurdles at the moment is cost, and the cost is related in part to manufacturing yields that, while not really horrible, are significantly behind those for small TFT-LCDs. (The OLED yield may be up to 70% by now and the TFT-LCD yield is probably well over 90%.) The other part of the cost problem is manufacturing processes for the OLED (or OEL) materials and the active-matrix backplane that are not scalable to large substrate sizes. This makes small displays more expensive than they would be otherwise, and it makes large displays not feasible at all.

So, a crying need in the AMOLED world is new manufacturing processes that can generate high yields on large substrates. That makes last week’s announcement from DuPont and Dainippon Screen Manufacturing a genuinely big deal:

"DuPont and Dainippon Screen Manufacturing Co., Ltd., …announced their intention to form a strategic alliance to develop integrated manufacturing equipment for printed organic light emitting diode (OLED) displays. The companies also have signed an agreement relating to their intention to bring together the elements needed - materials, technology and equipment - to mass produce OLED displays, delivering higher performance at a lower cost."

DuPont’s and Dainippon Screen’s ambitions aren’t modest. "DuPont is applying its science to make possible more vivid displays that are lower cost than current LCD displays," said David B. Miller, group vice president, DuPont Electronic & Communication Technologies. And one target is definitely television.

The companies are developing integrated coating and printing equipment that will perform solution-based processing. What DuPont brings to the party is its small-molecule OLED materials that are capable of being processed from solution and associated process technology. DuPont showed prototypes based on the technology at SID last year.

Dainippon Screen has developed nozzle printing, in which the OLED materials can be printed accurately at very high speed. Nozzle printing differs from ink-jet printing in that nozzle printing produces a continuous spray. With RGB-stripe displays, spraying a continuous stripe of OEL material is an obvious thing to do. Ink-jet printing for display fabrication has proven more difficult to develop than originally anticipated because obtaining the necessary uniformity of material dots on the substrate, which dry from small droplets, is not easy.

Developing this kind of technology does not happen overnight, and the two partners have been working together over the past three years. The first production-scale printer is being built now.

In a far less credible announcement last Friday, which was reported by the Japan Corporate News Network, Sumitomo Chemical said it plans to launch the production and sales of large-screen polymer OEL display panels for 40-inch and larger TVs in 2009.

Sumitomo Chemical president Hiromasa Yonekura said his company is considering forming alliances for the development of these panels. Wait a minute. He’s thinking now of forming an alliance in the future that will somehow produce and sell panels next year. We can admire Yonekura-san’s optimism.

You may recall that Sumitomo Chemical purchased Cambridge Display Technology and its polymer OLED and ink-jet technology. From a business point of view, the main benefit of polymer OLED was that it was the only material type compatible with ink-jet printing, which was the only way (at the time) to do solution processing. A Sumitomo Chemical spokesman seemed to think that’s still the case when he said that because polymer OEL panels can be produced through an ink-jet printing process, it is possible to lower production costs and make large displays. But polymer and ink-jet is no longer the only game in town.

It will be interesting to see what DuPont and Dainippon Screen have to say in LA next week about a production timeline. Clearly, they’ve already gotten beyond "thinking about forming an alliance."