Category Archives: Flexible Displays

August 7, 2006 – Arrowhead Research Corp. and the U. of Florida say they will collaborate on development of flexible thin-film transistors (TFT) using carbon nanotubes, targeting applications in the flexible electronics market projected to top $20 billion by 2012, according to NanoMarkets forecasts.

Under the agreement, Arrowhead will provide $647,000 over a two-year period to develop optimized TFT devices and prototypes of TFT arrays, supporting research done by U. of Florida physics prof. Andrew Rinzler. Arrowhead also will have the first option to exclusively license and commercialize the technology.

June 9, 2006 – Korean fabless chip firm Tomato LSI says it will produce the world’s smallest single-chip IC driver for amorphous silicon TFT VGA display panels, utilizing technology from Clairvoyante, in response to demand for high-resolution panels used in handheld mobile devices.

The 21.9×1.45mm LCD driver IC, now being sampled, will support panels up to 3.0-in. diagonals, and support up to 262K colors and visual resolution of up to 480×640 and standard data formats, while requiring only two-thirds of the memory and source drivers of standard RGB stripe smart driver ICs. Integrated gate driver support will further reduce the chip size and number of transistor contacts.

The companies claim Clairvoyante’s “PenTile” technology provides inroads for older amorphous silicon display producers into the VGA display market, because it requires only minor production modifications, and uses fewer TFTs and columns. They also claim the technology improves display performance by reducing power consumption by more than half, or more than doubling brightness.

“This new chip will be at the cutting edge of power efficiency for aSi driver chips,” stated Joel Pollack, president and CEO of Clairvoyante. “We believe the development of this PenTile VGA driver chip will be a key building block to facilitating development of the high-resolution displays needed to encourage adoption of new generations of mobile products.”

“The addition of data-centric features such as cameras, enhanced audio, and internet capabilities continues to increase the demands for higher resolution displays and more power-efficient portable devices,” added Justin Sy Hong, president and CEO of Tomato LSI. The new LCD driver will “offer display manufacturers a fully optimized, single-chip solution that will enable them to develop VGA resolution displays faster without sacrificing brightness, power efficiency or cost.”

April 4, 2006 – IMEC and its associated laboratory at the U. of Ghent have developed a new process flow for ultrathin chip packages resulting in bendable packaged chips. The process has been demonstrated with silicon chips thinned down to 20-30µm, with total thickness of 50µm.

The technology enables embedding packaged of chips in a wide variety of applications, such as smart textile and flexible displays. The process flow has been developed within the EU funded FP6 Integrated Project, SHIFT (Smart high-integration of flex technologies).

The base substrate used in the process is a 20µm thick polyimide layer spin-coated on a rigid glass carrier. A layer of bicyclobutane (<5µm thick), resistant to high curing temperature of the top polyimide, is used to glue the chips on the layer. Placing the chips in either a vacuum or with dispensed bicyclobutane enables void-free bonds -- current research is focusing on optimizing the chip placement on dispensed (pre-cured) bicyclobutane, and on controlling the dispensed quantity to avoid voids, to eliminate the need for a vacuum environment.

After curing the bicyclobutane at 350°C, the chip is fixed on the polyimide layer, with a 20µm covering polyimide layer spin-coated on the fixed die. Contact openings are laser drilled to the bumps of the chips; via diameters with top diameter down to 20µm are achieved by using a shaped laser beam. A top metal layer of 1µm TiW/Cu is sputtered and photolithographically patterned, metallizing the contacts to the chip and providing a fan out to the contacts of the chips.

February 23, 2006 – Vitex Systems Inc., San Jose, CA, a developer of equipment and films used for organic light-emitting diode (OLED) displays, says it is changing its business model to focus on licensing IP for its thin-film encapsulation technology. The company’s portfolio includes a monomer condensation and ceramic deposition system (named “Guardian”) to deposit alternating layers of polymer and ceramic films (called “Barix”).

As a result of the move, Vitex will close its Windsor, T pilot production facility, where it had manufactured its roll-to-roll “Flexible Glass” technology, and will licensing the core IP to substrate manufacturers who possess high-volume roll-to-roll manufacturing capabilities.

“Since our strengths lie with our patent portfolio and engineering services capabilities, it makes perfect sense to shift all of our efforts to this approach, which will subsequently allow us to reduce our operating and manufacturing costs and maximize profitability,” stated Robert Jan Visser, Vitex’s CTO.

OLED displays are the target market — Visser noted that displays leveraging Vitex’s Barix and Flexible Glass technologies could be up to 50%-90% thinner and lighter in weight and significantly lower in cost, with added benefits of various degrees of flexibility. However, the company also sees applications for its thin-film encapsulation technology in a wide array of organic optoelectronics markets, including smart labels/ID tags, thin-film batteries, solid-state lighting, optical networks, solar cells, and smart cards

October 4, 2005 – Seiko Epson Corp. has made what it claims is the world’s first bendable SRAM (static random access memory) device, using low-temperature polysilicon TFTs (thin film transistors), according to the Nikkei English News.

The manufacturer of information-related equipment, such as printers and electronic devices, plans to develop a commercially viable product, by reducing the prototype’s circuit linewidth of 3 microns to <1 micron. The company expects the bendable SRAM to find uses in IC cards and other products.

The prototype, which measures 10.77 x 8.28mm and is 200 microns thick, has a memory capacity of 16 kilobits. The SRAM is made by lithographing circuits formed on a glass substrate onto a flexible substrate.

L.L. Moro, N.M. Rutherford, X. Chu, R.J. Visser, Vitex Systems, San Jose, California

All electronic and optoelectronic devices require protection from the influences of the environment. A thin-film, transparent, and flexible moisture and gas barrier called Barix can be applied at low temperatures (e.g., <80°C). Although this type of barrier layer can be used in many applications, its attributes make it a key enabling technology for creating plastic flexible substrates and for thin-film encapsulation of new generations of organic-based electronics such as organic light-emitting diode (OLED) displays, organic solar cells, photovoltaics, and large-area OLED-based lighting.

The OLED application is especially challenging since it requires a coating with very low water vapor permeability (WVTR) of <5x10-6g/m2/day. Currently, displays are being protected by glueing a glass lid — with a cavity filled with desiccant — on the backside of the display, which effectively protects the display against degradation from the environment, but doubles its thickness. The purpose of the thin-film barrier coating is to reduce the thickness and cost of the displays.

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The possibilities include electronic devices produced so cheaply they could almost be one-time “throw away” products, better large-area electronics such as flat panel screens, or flexible electronics that could be folded up for ease of transport.

(December 29, 2004) Gaithersburg, Md.&#8212A low-power, magnetic sensor about the size of a grain of rice that can detect magnetic field changes as small as 50 picoteslas &#8212 a million times weaker than the Earth’s magnetic field &#8212 has been demonstrated by researchers at the National Institute of Standards and Technology (NIST).

September 8, 2004 – EV Group, Scharding, Austria, is expanding its operations in North America in response to increased business and customer demand. EV Group Inc., the company’s US subsidiary, will combine its headquarters, Technology Center, and Customer Support Division in the ASU Research Park in Tempe, AZ.

The new facility offers a state-of-the-art Class 10 production cleanroom. An onsite lab will include the company’s entire equipment range for demonstrations, customer training and process development.

In addition to being a tenant in the facility, EV Group has accepted an offer to become a principal partner in the Flexible Display Center, a research project between Arizona State University and the US Army. The company will work closely with all other partners to develop commercial solutions for the flexible display industry.

Along with its expansion in the ASU Research Park, EV Group will move its East Coast operations from Cranston, RI, to the Albany NanoTech facility at the University at Albany-State University of New York. The facility, which uses EVG equipment for nano-science and nano-engineering research, provides a more centralized location for serving customers in the Northeast.

June 17, 2004 – You’ll have to try this as a thought experiment if you’re not in Japan: Imagine you’re reading this on a handheld device the size of a paperback book. The device looks like an over-sized Palm handheld, except the screen doesn’t glow. Instead, it reflects the light around you, like paper.

Would you switch to a handheld electronic device?

Sony Corp. is betting you will say yes. It unveiled a new e-book device in April in Japan, a move that once again will test the e-book idea.

The consumer electronics industry asked readers what they thought of e-book devices previously. The late 1990s technology frenzy led to e-book devices from RCA and GEMStar, the publisher of TV Guide, as well as various startups.

The majority of those e-book products are no longer manufactured. Adding insult to injury, Barnes & Noble shelved its sales of e-books — the digital content displayed on the devices — last year.

Analysts point to various reasons earlier types of e-book devices didn’t catch on. They were power hogs. You couldn’t read them outside due to glare. They were expensive.

Compared with the refined, time-proven, inexpensive form of the entrenched technology — regular books printed on paper — e-book devices just couldn’t compete. Books are portable, cheap and easy on the eyes.

You only have to pay for them once and you can read them as often as you like, or even lend them to others. And if you lose or destroy one you’re not out much money.

The new generation of e-book devices rectifies some of the problems. Sony’s LIBRIe and others, like the Sigma eBook announced by Panasonic, use “bi-stable” displays. Unlike conventional liquid crystal displays (LCDs), bi-stable displays only use electricity when they change their content. Or to put it another way, you only drain the batteries when you change the page.

Bi-stable displays also differ from LCDs in that they are reflective rather than emissive; the page reflects the light around you. They don’t have lighting built into the back or sides of the display.

Drawback: You can’t read anything in the dark. Benefit: You can read everything, even in bright sunshine. The lack of backlighting also saves power.

Various technologies are incorporated. Sony’s LIBRIe uses a display from Philips with E Ink’s electronic ink inside. Panasonic’s Sigma eBook uses a display from Kent Displays.

However, while the new devices might have solved some problems, they’re still expensive. Sony’s new e-book costs $395.

“Another problem with these is that they’re rigid,” said Kimberly Allen, director of technology and strategic resources for iSuppli/Stanford Resources, an El Segundo, Calif.-based research and analysis firm. “That really wasn’t corrected.”

Ultimately, e-book manufacturers might be constraining themselves by focusing too closely on mimicking the form of a book, according to Allen. “There are things a book can’t do, like animated graphics,” she said. “Imagine the freedom you could have.”

She said other Japanese manufacturers are also working on similar products but “it’s still a technology push as far as I can tell.”

There is also the opposite view — that high tech will allow e-books to be more like regular books: cheap, rugged, simple. For that, e-books may have to wait until electronic ink displays are mated with flexible electronics.

A Philips subsidiary, Polymer Vision, announced just such a display prototype earlier this year. When it can get that product out the door at $20 a pop, good old-fashioned paper might finally have a worthy challenger.

 

April 19, 2004 – Xerox Corp. has developed a semiconductive ink that could make it possible to create low-cost, flexible transistor circuits by inkjet printing or other common techniques, according to a news release.

 

The ink can be used to print the semiconductor channels of transistors at low temperatures and in open air, which is required for low-cost manufacturing. Current methods require processing at high temperatures and under inert atmospheres, the release said.

 

Xerox also announced it has developed materials for printing the other components — a conductor and dielectric — necessary to make a plastic circuit. The technology could lead to cheaper flat-panel and flexible displays, as well as radio-frequency identification tags.