New silver-packing transparent conductive film could mean more durable touchscreens
We first heard of the wonders of silver ink back in 2009, but it wasn't until earlier this year, with talk of 3M's new capacitive touchscreens, that we experienced its real-world potential for display technology. Well, it looks like 3M's not the only name in the Ag game, in fact Tokyo-based Toray Industries recently announced the development of a transparent conductive film that ditches the traditional ITO (indium tin oxide) for silver wire. In order to produce this new material, a layer of Ag wires, measuring several hundred nanometers, is applied to a polyester (PET) film by way of a wet method. The result, the company said, is a more flexible, durable, and transparent film that is well suited to touchscreens of just about any size. There's no word yet on when the film will appear on real-deal devices, but we'll definitely keep an eye out for the silver screens. Full PR after the break.
Show full PR text
Toray Advanced Film Developed New Transparent Conductive Material Using Silver Nanowire Ink
- Best in the world in transparency and conductivity, superior flexibility, natural color, durability and workability; to be mass-produced for use in touch panels -
Toray Advanced Film Co., Ltd. (head office: Chuo-ku, Tokyo; President: Susumu Yamaguchi; hereinafter referred to as "the Company") today announced that it has succeeded in developing a silver nano-wire based transparent conductive film with the world's best transparency and conductivity -light transmittance of 90% or above and surface resistivity*1, which is a measure of conductivity, between 150 and 250 Ω/sq- using wet coating method. The material also boasts superior flexibility, natural coloration, durability and workability, and the Company expects to begin its mass production in the near future.
Transparent conductive films are generally ITO films*2 by use of vapor deposition or sputtering methods, making them not much suitable for bending as they are thin and brittle inorganic material, and they sometimes affect the flexibility of the final product. Furthermore, the primary raw material Indium being a rare metal, there is also the issue of depletion of resources. On the other hand, wet coating films using organic conducting materials, while superior in flexibility tend to be susceptible to discoloration*3 when conductivity is improved. They also have issues on durability under high heat and higher moisture circumstance though some products using such materials are available in the market. At the same time, in touch panel and display applications, it is necessary to not only have durability and reliability but also compatibility with pattern processing and other peripheral technologies without losing optical characteristics.
Against this background, the Company recently entered into a strategic partnership with Cambrios Technologies Corporation (head office: Sunnyvale, California; CEO: Michael Knapp), a U.S.-based electronic materials manufacturer, to develop a new product that addresses the above issues by bringing together high transparency, high conductivity nanowire ink technology of Cambrios with the Company's superior film processing technology.
Key technological points of the transparent conductive film developed this time using silver nanowire ink are as follows: (1) nano-level coating thickness control technology, (2) wet-method multilayer laminating technology, and (3) product design proposals that suit the fabrication process of the user. The product is considered better suited for mass production in comparison with ITO films which require sputtering or other such vacuum process. Also, given its superior flexibility and invisible patterning properties*4 in addition to high transparency and conductivity, the new film is expected to find application in touch panels used in cellular phones, smart phones and tablet PCs. The material can also address the need for lower resistance required by larger-sized touch panels and therefore the Company expects it to contribute to the display technology revolution in the future. Going forward, the Company hopes the film would eventually be used in 3-D touch panels, solar cells and organic EL electrodes.
