Kateeva’s YieldJet Printer Uses Inkjet-Printing to Produce TV Displays

Aiming to reduce the cost of manufacturing flexible and large-size OLED TV displays, Kateeva of Menlo Park, California has introduced the YIELDjet, an inkjet-printing manufacturing equipment solution to produce OLEDs in high volume. Kateva says the YIELDjet is the world’s first inkjet printer engineered from the ground up for OLED mass production.  When compared to existing manufacturing technologies, Kateeva says YIELDjet will enable dramatic yield improvements, which, in turn, will drive production costs lower. This it says is made possible by these technical achievements:

• First, YIELDjet is the only platform to feature a production-worthy pure nitrogen process chamber. Nitrogen is considered the gold-standard process environment for OLEDs, and an essential device lifetime enabler. YIELDjet doubles lifetime in certain applications;

• Second, YIELDjet reduces particles by as much as 10X, thanks to specialized mechanical design features. Such particle performance is a key yield accelerator;

• Finally, YIELDjet offers exceptional film coating uniformity with a process window that’s 5X wider than standard technologies.  Kateeva says this vastly improves process reliability and uptime.

When combined, these technologies offer display manufacturers a breakthrough solution to mass produce OLED devices more economically.

With R&D tools deployed at customer sites in Asia, and demand growing for production equipment, Kateeva is now pivoting to full-scale commercialization.

President and Co-founder Dr. Conor Madigan explained: “YIELDjet was inspired by a simple vision: help display manufacturers realize the full potential of OLED technology so that their customers can enjoy and benefit from these dazzling new displays. YIELDjet delivers by using inkjet printing to crack difficult technical problems that made manufacturing flexible and large-size OLEDs challenging and costly. We’re encouraged by our customers’ interest, and we’re excited to be enabling this important display technology transition.”

YIELDjet launches as the world’s first flexible and large-size OLED displays enter the market such as  55” OLED TVs that debuted this year. Dr. Jennifer Colegrove, President of Calif.-based Touch Display Research, expects that 2016 will be the take-off year for OLED TVs.  By 2020, she predicts that the market will reach $15.5 billion.

Meanwhile, the vision of wearable computing products is becoming reality thanks to the paper-thin, ultra-light characteristics of flexible OLEDs. This sector is also poised for trajectory, with IHS Inc. predicting global market revenue for flexible OLEDs  to soar from $21.9 million in 2013 to $94.8 million in 2014. By 2020, this figure will rise to well above $5.5 billion according to estimates by several market research firms.

However, Kateev says that formidable manufacturing bottlenecks persist. Existing OLED manufacturing is constrained by vacuum-evaporation techniques that use shadow masks for patterning. It’s a simple and well-established technique, but inefficient, difficult to scale, and prone to yield-killing particles. Inkjet printing is considered the ideal replacement with advantages such as speedy throughput, excellent scalability, high efficiency, and potentially better particle performance (by eliminating shadow masks). But while well-proven in desktop printing applications, inkjet technology has not yet scaled to mass produce OLEDs.  Many companies are attempting to exploit the known benefits and make it work for OLEDs.  Until now, however, no solution successfully tackles all of these production challenges: inadequate process environment control, high particle levels, non-uniformity, inconsistent reliability, and poor uptime performance.

Kateev says YIELDjet breaks the impasse. With a novel architecture and design features, YIELDjet enables superior device lifetime and quality, ultra-low particle performance, and better process reliability and uptime.

Three key innovations are central to the solution:

• First, Kateeva tackled device lifetime. For customers, this is the single most important device characteristic. In a technical breakthrough, the company developed a production worthy way to enclose the tool in a pure nitrogen chamber. Nitrogen is the ultimate OLED processing environment.  It shields OLED materials from moisture and air (known degraders of quality), and enables consistently superior device lifetime. Early data shows that with YIELDjet, device lifetime in certain applications more than doubles.Kateeva is not the first to master the pure-nitrogen technique, but says it’s the first to make it production worthy by improving serviceability. A smaller process enclosure speeds post-maintenance recovery and replacement of print heads without exposing the enclosure to air. With this innovation, downtime drops from as much as 24 hours to less than two.

• Second, Kateeva confronted particle contamination, a guaranteed yield killer. Borrowing stringent protocols from the semiconductor industry, Kateeva equipped YIELDjet with advanced mechanical design features that sharply reduce particle generation, eliminate turbulence, and quickly capture any particles generated. The result is a 10-times reduction in particles when compared to commonly used OLED production techniques.  Kateev says it’s the most aggressive particle performance ever demonstrated in the print industry.

• Finally, Kateeva optimized YIELDjet for reliability and uptime.  xceptional coating uniformity is a strict requirement for production-quality OLED displays. YIELDjet provides such uniformity with an ultra-wide process window—five-times wider than standard technologies—achieved via unique algorithms and superior process control technologies. Beyond improving reliability and uptime, these capabilities enable Kateeva systems to bridge the gap from small-volume R&D demonstrations to high-volume mass production.