Flexible consumer electronics products are closer to Main Street thanks to a new manufacturing tool from Kateeva.
OLED is the only technology that can enable the ultra-light, paper-thin displays that make bendable electronic gadgets possible. And with key proprietary innovations, the YIELDjet FLEX is the only customer-proven technology of its kind that can enable cost-effective manufacturing of flexible OLED displays in high volume.
Kateeva President and Co-founder Dr. Conor Madigan called the YIELDjet FLEX the first real gateway tool for flexible products. He noted: "Flexible OLED panels will give shape to amazing consumer experiences. For example, pocket-sized tri-fold smart phones that unfurl to triple the screen size for immersive viewing; curved and flexible smart watches that are richly functional and comfortable to wear; and vehicles featuring paper-thin, surface-conforming displays that enhance aesthetics and improve usability. We're excited to give display manufacturers new horsepower to cost-effectively mass produce flexible OLED panels that make such imaginative products possible."
The YIELDjet FLEX tool was developed to enable Thin Film Encapsulation (TFE), which is the process that gives thinness and flexibility to the OLED device. It is the first product to emerge from Kateeva's YIELDjet platform, a breakthrough precision deposition technology platform that uses innovative inkjet printing to cost- effectively deposit coatings on complex applications in volume-manufacturing environments.
The system debuts as the power of OLED technology surges. Its advantages can already be found in rigid OLED displays featured in smart phones and other mobile devices. Flexible OLED is the next frontier. Until now, though, encapsulation has been a major challenge for the commercialization of flexible OLED displays, says IDTechEx Technology Analyst Guillaume Chansin. He added: "The launch of an inkjet deposition tool is a significant milestone for the display industry. Recent announcements by the leading OLED manufacturers show there is strong momentum in mass production of displays that are thinner, lighter, and bendable. IDTechEx forecasts the market for plastic or flexible OLED displays will grow to $16 billion by 2020."
Flexible OLED is a natural application for the first YIELDjet product. Inkjet enables superb particle performance, high efficiency and excellent scalability—key OLED mass-production imperatives. But although long considered an ideal alternative to older OLED production technologies, only Kateeva was able to solve the technical problems that previously prevented inkjet printing from scaling. And until the YIELDjet FLEX, no inkjet printer was qualified for TFE mass production in a customer's pilot line.
TFE is an exceptionally complex process. At the center is a multi-layer stack of thin-film materials that are highly sensitive to oxygen and water. Particles on any layer cause defects throughout the device, and even the slightest uniformity aberration will distort the display image. The current production approach is vacuum evaporation. It's a well-established technology that uses shadow masks to deposit the layers in a stencil-like process. However, it is slow, inefficient, difficult to scale, and prone to yield-killing particles.
Inkjet technology is the breakthrough replacement for TFE. Inkjet can deposit thick films at very high speed, with superb precision and very few defects. Shadow masks are eliminated, which drastically reduces particles. High-yield stacks can be achieved with fewer films than evaporation, and, most importantly, inkjet is scalable to G8, which gives display manufacturers an extendible production solution as the industry shifts to larger substrate sizes.
YIELDjet FLEX: Gateway Tool for TFE Mass Production
The YIELDjet FLEX tool features these innovations that equip the tool for TFE mass-production lines:
- Optimum Process Environment: The YIELDjet FLEX is enclosed 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. Kateeva is not the first to make OLED devices in nitrogen, but it is the first to master the technology and make it production worthy. This is achieved 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. With the Kateeva approach, monitoring and control of the environment is also enhanced.
- Superior Particle Control: Advanced mechanical design features sharply reduce particle generation, eliminate turbulence, and quickly capture any particles generated. Particles are reduced by more than 10X when compared to conventional OLED production techniques.
- Inherent Planarization: Unlike vacuum technologies, the YIELDjet FLEX coatings provide exceptional planarization of substrate surface structures and particles. Proper ink formulation is essential, which is a particular area of Kateeva expertise. When optimized, the ink loads the surface like water filling a bathtub, flowing in and around surface features and for sufficient thicknesses, completely covering them. Upon curing, the shape is retained and the top surface of the solid film is flat and completely planar. Such planarization enables the fabrication of TFE structures with lower internal stress and greater resilience to repeated flexing and bending.
- Unprecedented Film Uniformity: In addition to the planarization advantage, the YIELDjet FLEX deploys unique monitoring techniques and special printing algorithms that further enhance film uniformity and deliver mura-free coatings that exceed customers' specifications.
Dr. Madigan presented YIELDjet FLEX at the Printed Electronics USA Conference in Santa Clara, California last month. His presentation was titled "Inkjet Technology for Mass Production of Flexible Displays".
Source and top image: Kateeva
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Learn more at the next leading event on the topic: Printed Electronics USA 2019 on 20 - 21 Nov 2019 at Santa Clara Convention Center, CA, USA hosted by IDTechEx.