20th October 2008

 

 

Highlights from the IDTechEx Printed Electronics Asia 2008 event, Tokyo, Japan, by author Raghu Das.

 

 

238 people attended the IDTechEx Printed Electronics Asia 2008 conference and exhibition on October 8-9 in Tokyo, Japan. Over 75% of attendees were from Japan and Korea, and they included companies such as Toppan Forms, Panasonic, Dai Nippon Printing, Sony, Samsung, Toyota, Mitsubishi Plastics, Brother Industries, Teijin, Konica Minolta, Mitsui, Toshiba and Honda to name a few.

 

 

The keynote speaker of the event was Mr Utaka, the Managing Director of Toppan Forms. Toppan Forms is a billion dollar maker of special papers and forms, and is working with technology from Kovio, Konarka, Power Paper, SiPix and others. Mr Utaka described the importance of providing a strong interface to consumers and hiding the technology so they do not see it. He showed concepts including a map at a theme park which alerted users to where they were in real time and alerted them to special events, all on a foldable sheet of paper. Toppan Forms has also commercialized the technology in products such as "audio paper" - a flexible paper based device which can record messages. It incorporates a printed battery, conductors and thin a film speaker.

 

 

Kovio CEO Amir Mashkoori spoke of their set up in their new 95,000 square foot facility in California, which includes a 22,000 square foot clean room. Using a nanosilicon inkjetted ink, mobilities of over 300 cm²/Vs have been achieved in the lab. They are able to achieve 10 micron feature sizes using inkjet printing and initially will be making RFID tags on 300 mm² stainless steel substrates. They intend to launch product imminently rather than waiting a few more years to achieve roll to roll processing.

 

 

Hewlett Packard discussed their development of imprint lithography on a roll to roll basis to pattern transistors for display drivers. They achieve feature sizes of 100 nm.

 

 

Thin Film Electronics preview products

 

Polymer memory developer Thin Film Electronics of Sweden previewed a 15 bit 1 cent memory device in gaming cards, soon to be a commercial product. Higher memories were also shown which will be used in a medical application.

 

Photovoltaics

 

Several companies spoke of progress with non silicon PV technologies. Gifu University, working with Sekisui Jushi Corporation, has been developing Dye Sensitized Solar Cells (DSSC) and expect first products to appear over the next few years. The cells can be coloured depending on the dye used and applications already are red road signs where the sign is a solar cell which powers LEDs on the sign at night. Conventional PV is not suitable here because that would use glass which is dangerous on a road sign.

 

G24 Innovations, also working on DSSC, say their first orders are now in hand. The company has developed roll to roll manufacture of DSSCs in Cardiff, Wales. Output is capable of achieving 20MW production. They can process 1 km of PV in 2 hours. A second line is due to be completed in mid 2009 which will add a further 25 MW. The company has also received planning permission to install a wind turbine - they intend to be operated completely from renewable energy.

 

 

Fang-Chun Chen from Taiwan published results of using microwave annealing on polymer solar cells, which decreases the anneal time to just 90 seconds.

 

Sony spoke of development of printed OTFT for display drivers - a 10.5" VGA fully printed backplane has been achieved. They worked with Toppan Printing on this. Issues they are working on are improving TFT deviations, getting wiring to less than 10 microns, handling flexible substrates and thermal Shrinkage.

 

 

OLEDs

 

A number of players no longer see entirely organic devices as the end game, though some do. For example, in its OLED displays, Samsung is testing inorganic passivation, transistor gates, barrier layers and electrodes as well as organic alternatives. Materials include Cu, SiO2 and SiNx. One ink jet layer has replaced six earlier layers in a display. However, the challenges have increased because, "Our concept has changed to flexible displays," said Dr Bonwon Koo of Samsung Display Laboratory in Korea. There are no longer any illusions about selling OLEDs at a premium against LCDs given the tremendous progress with LCD viewing angles and other features. "We need to be cost competitive with LCD" said Dr Reid Chesterfield of DuPont Displays, adding that, "The holy grail of OLED development is life."

 

 

At least the OLED developers are open about life and it was interesting to hear that, although blue is traditionally the color with least life, in actual devices, other colors can be limiting. DuPont is unfazed by the rush to inkjet: it uses slot coating and nozzle printing as appropriate.

 

Others mentioned flexographic printing. Dr Kiyoshi Yoneda of Kodak Japan presented its white OLED approach to displays and lighting where 40% reduction in power consumption comes with a few problems that can probably be solved in due course, working with Dainippon Screen of Japan.

 

Displays were neatly categorised into those for watching - where OLEDs are seen as the most important future product - and those for reading - where E-Ink front planes are dominant and the reading A4 and A3 formats are of particular interest, not least because existing printed text does not need to be reformatted. Bridgestone of Japan is the potential competition now Xerox has got out of the business and its electrophoretic product, which uses air instead of water, will be launched in 2009.

 

Advantages seem to be faster response, tolerance of low temperatures and no need for a polarizer or reflective layer. However, the operating voltage at 70-80V is about double that of E-Ink. E-Ink of the USA will launch color versions of its front planes in 2010.

 

Materials

 

As for materials, there was much discussion of how to optimise inkjet systems for various tasks, the PixDro tools and modules and a novel flexographic printing process from Asahi Kasei Chemicals in Japan.

 

Competitors Merck Chemicals and BASF, both of Germany, were in agreement as to what has to be achieved in further developing the various OLED and transistor inks and they described their progress. Of course, mobilities and thus operating frequencies of organic transistors need to improve but Dr Peter Eckerle of BASF counselled that, "The main challenge in RFID is high yield in production." HC Starck has improved its PEDOT-PSS conducting printing ink to give a wider range of compromises in properties as needed for different printing technologies and applications. For example, the acidity is quenched in a version that surrenders a modest amount of conductivity to achieve this. Sadly, there is still no widely used replacement for indium tin oxide ITO despite indium prices rising and these films emitting oxygen and having limited rollability. However, Hitachi Chemical of Japan announced its copper inks that cure at low temperature to maintain solderability. That may reduce worries about recent trends in the silver price, though another approach is to use truly nanosilver that requires much less material. Frontier Carbon Corporation of Japan described its huge repertoire of fullerene formulations. Professor Takao Someya of Tokyo University discussed his stretchable electronics and his transistors, memories and circuits made using sub femtoliter inkjets.

 

Company Visits

 

IDTechEx is well known for organising visits to local centers of excellence alongside its conferences. It opens doors to premises not normally available to many delegates. Printed Electronics Asia was no exception. Attendees were treated to visits to the University of Tokyo and the skyscrapers of Sony, Toppan Forms, Mitsubishi, Dai Nippon Printing and Toppan Printing in central Tokyo.