Toppan Printing and Sony Launch "Full Print Technology" Flexible Electronic Paper

Toppan Printing and Sony's research team succeeded in driving 10.5-inch and large-size flexible electronic paper on organic TFT backplanes based on the "full-printing process." The results were announced at "IDW (International Display Workshops)" held from December 5th to 7th. The drive is a 10.5-inch VGA microcapsule electrophoretic display. In order to form a conductive layer and an organic semiconductor layer, a new printing method has also been developed.
Previously, the use of printing methods to produce 10.5 inch VGA-level organic TFT arrays, there are two major problems. First, it is difficult to support this fine-tuned short channel TFT. It is difficult to achieve a microfabrication of 20 μm or less using the conventional screen printing method, and the high-definition inkjet method has a small throughput and does not support a large size. Second, the three conditions of high mobility, high on-off ratio (On-Off Ratio), and low threshold voltage required to drive the display are difficult to achieve at the same time.

"Full Print Process" Organic TFT Backplane Drives 10.5-Inch and Large-Size Flexible Electronic Papers This time, Toppan Printing and Sony's research team successfully developed support for high-definition displays by developing new printing methods for conductive layer formation processes. Short-channel TFT. In order to form a conductive layer (gate, storage capacity, source and drain), a new high-resolution printing technology based on offset printing was developed. As a result, line widths and line spacings of 5 μm can be supported, achieving a practical level of throughput, while also achieving a large-size support function comparable to the original printing method. The conductive layer material uses Ag nanoparticles.
Further, the team realized the TFT characteristics sufficient to drive the display by optimizing the organic semiconductor solution process and the ink jet process. The migration rate reached 0.05 cm 2 /V·s, the on-off ratio reached 10 6 and the critical voltage reached 6V. Organic semiconductor materials use TIPS-pentacene that can be converted into a solution.
At IDW, the team used photos to show the status of the electrophoretic film that drives the United States Enk.