Fabrication of Electrophoretic Display Driven by Membrane Switch Array

Abstract

Electrophoretic devices (EPDs) and organic light-emitting diodes (OLEDs) have potential application in a large-area flexible displays, such as digital signage. For this purpose, a new backplane is capable of driving a large unit is required instead of thin-film transistors. In this paper we describe the fabrication of a membrane switch array suitable for driving large-scale flat-panel displays. An array of membrane switches was prepared using flexible printed circuit (FPC) technology of polyimide films, by combining low-temperature processes of lamination and copper electroplating methods. An array of 256 matrix switches with a pixel size of 7 mm2 was prepared to drive the EPD front panel. The switches were driven at a voltage of about 40 V and a frequency of 10 Hz. The operation characteristics agreed well with the result of the theoretical calculation. The calculation also suggested that driving voltage can be lowered by increasing pixel size. The contact resistance of the membrane switch was as low as 0.2 Ω, which implies the wide applicability of this device for driving a variety of elements.

Copper cladding on polymer surfaces by ionization-assisted deposition

“…A typical FPC consists of a polyimide (PI) base film cladded with a copper foil with an adhesive. On the other hand, the application of FPC is extending toward increasingly complicated devices such as membrane switch matrices 10) and bare chip mounting. 11,12) Recent requirements for reducing the line width of the circuits and minimizing the thickness of the base film have come to a point where the thickness of the adhesive layer can no longer be neglected.…”

Influence of membrane layer properties on the electrophoretic behavior of a soft particle

“…Electrophoresis 1 is applied widely in various processes in practice such as separation 2–5 and thin film fabrication 6–8, and used as a driving mechanism in applications such as e‐paper display 9–11. Owing to its versatile potential applications, the electrophoresis of soft entities becomes one of the most attractive research topics, recently.…”

Proposal of Fast-Moving Ball Actuator Mode for Electronic-Paper Displays

“…It is different from conventional electrophoretic displays, which have been developed using the electrophoretic phenomenon of charged particles suspended in a fluid. Several types of electrophoretic display have been proposed including microencapsulated or microcup electrophoretic displays, [1][2][3][4] twisting ball displays, 5) toner displays, 6) and in-plane electrophoretic displays. 7,8) In the case of electrophoresis, which involves the motion of charged objects in a fluid in response to an electric field, there are problems of lateral drift and agglomeration.…”