Flexible, printed electronics sector grows, but challenges remain

By Tom Cheyney, Small Times Senior Contributing Editor

February 4, 2008 — Smart credit cards with embedded displays, e-packaging with printed RFID chips, and mobile devices with rollable, e-paper screens are among the growing number of flexible electronics-enabled gizmos that have reached or about to reach the commercialization stage. A sector once dominated by artists’ renderings has evolved significantly over the past several years, as more production has come online, delivering both critical materials and real products. Despite the gains, many significant manufacturing and infrastructure challenges remain for flexible, printed, and organic electronics (FPOE) to become a multibillion-dollar market.

At the U.S. Display Consortium‘s Flexible Electronics and Display conference held January 21-24 in Phoenix, a parade of speakers talked about their own breakthroughs in moving toward volume fabrication. Dennis Brestovansky, president and CEO of Aveso, described how the spinoff of Dow Chemical uses a proprietary family of electrochromic inks “that change color when low voltage (<1 volt) is applied within a confined electrical field" for its printed, high-contrast flexible display devices. This material technology enables the creation of low-cost, 250-micron-thick, rugged "active label" displays that can be manufactured using screen, gravure, and flexographic roll-to-roll (R2R) printing methods.

The company’s Primero modules can be integrated into ISO-compliant one-time password and other “secure” smart cards made with hot lamination, which Brestovansky said “is the key to producing a low-cost, high-volume electronic display card. You can drop these parts into any membrane switch factory and be running products in days.” The “adoption of the new card technology hinges on its ability to deliver volume, pricing, and process,” he added, noting that the “installed global infrastructure of approved secure card facilities must be leveraged.”

Not every flexible electronics device is as “simple” to make as a display card or can tap into a mature manufacturing and supply chain infrastructure. A recurring theme runs through discussions of FPOE’s volume-production potential: The higher the information content and the larger the substrate area of the device being developed, the more complex — and costly — the manufacturing will likely be, with nonvacuum R2R processing being especially tricky.

Some companies have chosen a hybrid approach for getting on the fast-track to mass production, piggybacking flexible processing onto existing vacuum thin-film-transistor manufacturing infrastructure. Presenters from Polymer Vision, Prime View International (PVI), and Samsung discussed their reliance on low-temperature semiconductor/LCD processes, running the new products through existing lines, adding a few specialized tools and materials and employing glass or wafer carrier/support substrates, on which the plastic film or metal foil is laminated during the process and delaminated at the end.

Polymer Vision CTO Edzer Huitema said his company “is making thousands of rollable displays” at its Southampton, U.K., fab (which uses 150-mm silicon wafers as carriers), in preparation for the midyear commercial launch of its first Readius mobile reader devices. PVI is ramping to volume production of its Phillips-invented Flexi-e displays (which, like the Polymer Vision and Samsung devices, employ E Ink’s Vizplex microencapsulated electrophoretic e-paper film) at its Gen 2.5 TFT-LCD factory in Hsinchu, Taiwan. Flex displays “run side by side” with glass, using “standard production equipment as much as possible” and showing “similar TFT characteristics and stability” as their glass counterparts, according to company chairman/CEO Scott Liu.

For those pursuing an atmospheric, solutions/functional ink-based, additive printable electronics approach, one weak link is the lack of a high-end, PE-specific, roll-to-roll process equipment infrastructure. Dan Gamota, director of printed electronics at Motorola (which has “not done anything in vacuum—we’ve used all graphic arts” techniques), told Small Times “people are realizing that…along the supply chain, the silver bullet is not materials—the equipment needs to be developed.”

He believes “things are going in the right direction,” however: Several large tool companies have approached Motorola about starting focused businesses; the R2R pilot line is coming online at the Center for Advanced Microelectronics Manufacturing (CAMM) at the State University of New York, Binghamton; and the new iNEMI organic and printed electronics roadmap (due out in early 2009) will focus more on equipment and processes. Also citing ongoing work at Toppan Forms and Degussa, Gamota thinks that “this year we’ll see lots of activities in tooling.”


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