A cleaner, more cost-effective deposition approach

Materials usage is typically the largest CoO component in OLED manufacturing. With inkjet, virtually all of the deposited material forms the finished film. This means there is almost no waste. Mask-dependent approaches, on the other hand, deposit much of the material on the chamber walls or the mask.

Inkjet improves CoO by eliminating the cost of manufacturing, cleaning and replacing masks. Uptime is also higher because there are no production interruptions to clean the chamber walls. Finally, with no superfluous material on the masks or chamber walls to flake off and contaminate the panel surface, defects are dramatically lower.

Flexibility = faster time-to-market

Inkjet provides flexible manufacturing for display producers, which enables quick turn-around on customer requests, and ultimately, faster time to market. If a display with a new shape is required in R&D or production, it involves a simple recipe change on an inkjet printer which can be done very quickly. With a system that uses a mask to define the shape, however, a new mask must be designed, tested, and manufactured for every new display shape, which is costly and time consuming. Inkjet’s inherent flexibility saves valuable time during all phases of the product cycle, from R&D to mass production.

Approach of choice for OLED thin film encapsulation mass production

OLED devices are extremely sensitive to trace levels of oxygen and moisture. Protection from these elements during operation is imperative. For flexible devices, thin film encapsulation using inorganic/organic multilayers has become the integration scheme of choice. The advantages discussed above have made inkjet the approach of choice for deposition of the organic layer of the TFE stack. The material efficiency, higher uptime, and superior defect performance were key considerations in the selection of inkjet for mass production of flexible OLED displays. In addition, inkjet provides more flexibility in the choice of material for the organic film, and the use of a liquid ink provides for better planarization of underlying particles and surface topology—a critical factor in TFE quality.