Breakthrough in Producing Printed Memory: An Interview
By Dr. Peter Harrop, Chairman, IDTechEx Ltd.
Thin Film Electronics, an Oslo, Norway-based company with R&D facilities in Linkoping, Sweden, known as Thinfilm, and InkTec Co. Ltd, known as InkTec, have together made a breakthrough in producing printed memory on flexible substrates. Here Dr. Peter Harrop of analyst IDTechEx, interviews Johan Carlsson, President and CEO of Thinfilm and Kwang-Choon Chung, President and CEO of InkTec, about the latest development.
PH: For a long time, IDTechEx has been advocating more effort on printed memory, one of the missing parts of the printed electronics toolkit that is vital for progress. Can you tell us about this latest breakthrough and the history of your company please?
Johan Carlsson: Our latest development concerns a joint Thinfilm and InkTec project with the aim of demonstrating R2R high volume manufacturing of printed memories. The project has been a huge success with the realization of a R2R production worthy printing process capable of realizing printed memory cells with a yield in the 96-97 percent range for the best device structure. Up to now more than 100 meters of roll has been produced with a total of five printing steps. This is to our knowledge one of the world first established R2R processes capable of producing electronic components other than conductors and antennas with high yield. It is especially impressive given that the printed memory film thickness is only about 200 nm.
Thinfilm is a public research and development company founded in 1997 with aim to commercialize its polymer memory technology. The most promising aspect of Thinfilm’s polymer technology lies in the fact that it is possibly the only nonvolatile memory technology that can be fabricated entirely by printing. Thinfilm’s technology is based on development that we initially performed together with Intel for the production of so called hybrid high density silicon-polymer memories. Together we produced working 512 MB chip modules in 0.25 micro technology and that was five years ago using Thinfilm’s unique polymer memory technology.
PH: That is extremely exciting and significant. How does the partnership with InkTec operate and what other partnerships are in place with Thinfilm?
Johan Carlsson: The partnership with InkTec is characterized by mutual trust, transparency, efficient and professional exchange of information. This has enabled us to quickly resolve technical issues. We are moreover, very impressed by InkTec's facilities at the second factory in Pyoungtaek just outside of Seoul which are entirely dedicated to printed electronics with class 10 000 clean room in general areas and class 1000 around production equipment.
Other important partnerships that are in place are with the like of Xaar plc, OTB (print equipment vendors), Solvay (polymer vendor), Soligie Inc. (Printed Electronic Manufacturer and Integrator), AGFA (conductive polymer vendor), DuPont Teijin Films (substrate vendor) and Cartamundi (Card manufacturer) and Weyerhaeuser (printed RFID developer) for the commercial production and marketing of printed memories.
PH: What is your roadmap for commercialisation of printed memory? Can you give us any dates and product specifications that will be achieved?
Johan Carlsson: Given our business model, i.e., licensing technology to partners for them to do the end user sales and manufacturing, makes it hard for us to give any dates as we don't control the entire value chain. But as we do work closely with all of our partners we know of some very exciting products that are in the final stage of design, and should if everything will be on plan, they will be introduced in the market sometime early next year. The results achieved with InkTec are a major milestone in meeting the schedule.
PH: One area of printed electronics starting to get great attention is transparent electronics with flexible transparent batteries, photovoltaics, lighting, transistors and so on being demonstrated. Clearly transparent electronic film will not detract from branding on packaging and it can go in many places where electronics cannot currently be applied. Will there be a transparent Thinfilm memory?
Johan Carlsson: Thinfilm's memory polymer is in itself transparent which means that a transparent memory cell can be made with any transparent electrode material. This means that transparent cells can easily be made as soon as integration with a suitable transparent electrode can be achieved. We have for example already in 2005 demonstrated printed memories using the conductive polymer PEDOT/PSS as electrode material which is nearly transparent.
PH: One other dream for printed electronics is printing many components on top of each other. This will save space and eliminate the wiring needed by conventional silicon chips, displays and so on. Will Thinfilm memory be layered with other components one day?
Johan Carlsson: Certainly, this in fact one of the basic ideas behind Thinfilm’s hybrid memory technology where multiple layers of memory were used in order to increase memory capacity/unit area. All of the drive electronics was situated below the stacked polymer memories. When it comes to printed electronics this is all dependent on the solubility of various layers (electronics polymers) and/or development of processes through separation layers. So by using the right set of materials one can envision that our memory could be printed on top or below other components.
PH: What types of electronic device are going to be most suitable to adopt Thinfilm memory in the near future?
Johan Carlsson: We are currently aiming at the game cards and toys industry for our so called stand-alone memories (contact). These memories are also suitable for brand protection type applications. We are also working on integration of our memory technology with logic and we hope to soon be able to draw benefit of this work in terms of applications like fully printed RFID tags.
PH: What do you see as your main competition?
Johan Carlsson: To our knowledge there is no competing printed re-writable memory technology that is sufficiently mature to be of any near term threat. On the other hand, there are a number of companies and research groups that publish results on novel memory technologies that seem promising—one never knows what might appear and therefore we keep a close eye on the development and are open to cooperation.
PH: We are very excited that you are presenting at the forthcoming IDTechEx Printed Electronics Europe conference in Dresden and this announcement will be one of the most important firsts. What will you cover in your presentation?
Johan Carlsson: We will cover our latest results on volume production of printed memories. We will in particular share some important details as well as show video clips from the production.
PH: have you anything else to report at this stage?
Johan Carlsson: As I mentioned earlier, are we working with a number of partners in different areas. These projects are also progressing very well, why I foresee further announcements once we reach good technical results or commercial success. Just stay tuned—there's more to come!
PH: We understand and are very impressed that you now can print memories in a production facility. How do you foresee that this will impact printed electronics in general and specifically your own activities in this field?
Kwang-Choon Chung: We are very excited and particularly with the achievement of being able to produce the memories which rely on the integrity of a thin polymer film where the slightest defect will lead to a short. This is a real confidence booster both for printed electronics in general and in particular for us. This proves that our investment of a dedicated printed electronics factory was the right thing to do and this also opens up the opportunity for integration with other technologies such as transistors. Our prototype line is equipped with screen, gravure, flexo printing stations, a microgravure coating station, as well as an inline 12 m oven with five independent zones for thermal treatment—we are thus well equipped to do any kind of development. Thinfilm's unique memory technology will also add yet another market segment for our ink products and in addition another application to our successful Print Services business, which both will contribute to the continued growth of our company.
PH: We understand that you also develop and produce silver inks for the printed electronics industry. Can you tell us a little bit more about the characteristics and their role in this project?
Kwang-Choon Chung: Our ink is based on a proprietary silver complex compound and is thus non-particle based. This has been crucial, in particular, for roughness control and integrity of the printed memory film. Another important aspect of our silver complex compound is that most suitable solvents for the production of inks are entirely compatible with the printed memory film thereby avoiding shorts and the use of protection layers.
PH: What is your production capacity? Any plans of expansion?
Kwang-Choon Chung: Our printing lines are optimized for mass production. We have currently three Roll to Roll lines equipped with screen, gravure and flexo printing stations, as well as microgravure coating stations. Our annual capacity is around 10 million sq m at each line. We will consider both further facility expansion and dedicated lines for printed electronic applications.
PH: What other printed electronics components are you working on/producing?
Kwang-Choon Chung: We have recently printed a flexible printed circuit board (FPCB) product approved for mass production by a local partner. We have also focused on printing antennas which gives the highest volume and lowest cost by using flexible substrates and electronic materials. The antennas can be applied in the packaging, textiles and smart card industries. InkTec has also developed various functional films such as reflective film, EMI shielding and transparent conductive films, etc. by using our own electronic materials and printing facilities. These films are used by the display, signage and architectural industries as a decoration or functional parts.
