Although conductive polymer films were developed several years ago, they have not yet reached the level of practical application. The current mainstream conductive film is generally based on the PEDOT conductive layer. This film has good flexibility, small radius of curvature, and easy deformation, and is suitable for the top electrode of a resistive touch screen. Although the current radius of curvature of this ITO film cannot reach 8mm, it is possible to achieve a radius of curvature of 1mm through process adjustment, so it is expected to be used in narrow-frame touch screens. Compared with the rro film produced by the blasting process, the conductive polymer film can be produced by coating, thereby saving equipment investment and reducing production costs, but in terms of transmittance and resistance to high temperature and humidity It is not as good as an ITO film formed by a sputtering deposition process. It is said that there have been announcements before that, in the conductive polymer film, there are very similar application fields between the conductive polymer film and the ITO film.
Recent reports on carbon nanotubes (CNT), a conductive film used in touch screens. It has good electrical conductivity, high mechanical strength, and is expected to become a thin film to replace ITO. It is reported that the United States UNIDYM company has applied CNT to e-books and other fields. Several other companies are also working on the development of this technology. Because CNT has good mechanical properties, good flexibility, and strong adaptability to the environment, it is very promising to be used in solar cells and touch screens. The vacuum dry process of IZO (indium Zinc Oxide, indium zinc oxide) film is close to practical use; Yamamoto et al.'s ZnO film made by ion plating is not far from practical use. Although it has to be determined whether they can meet the long durability requirements of the electrode material on the top of the touch screen, EL is easy to etch, so it is more appropriate from this point. The IZO film has also been detailed. In terms of thermal stability, it has a relatively stable amorphous conductive layer.
The development of conductive films based on ITO powder has also been for many years, but it is difficult to achieve high light transmittance and low resistance. In terms of preventing electrification, there is still a long way to go from the practical use of touch screens. It is said that TDK has recently developed a conductive film with the same system and is used by some touch screen manufacturers. The characteristics of this film are not much different from the ITO film deposited by the sputtering process, and the wet process can be used, which has an advantage in price.
