Scalability of Roll-to-Roll Gravure-Printed Electrodes on Plastic Foils

• Published in: IEEE transactions on electronics packaging manufacturing Vol. 33; no. 4; pp. 275 - 283
• Main Authors: Jinsoo Noh, Dongsun Yeom, Chaemin Lim, Hwajin Cha, Jukyung Han, Junseok Kim, Yongsu Park, Subramanian, Vivek, Gyoujin Cho
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-10-2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Electrodes; Electronics; Exact sciences and technology; Flexible electronics; Gravure; Microelectronic fabrication (materials and surfaces technology); Printed electronics; Printing; roll-to-roll (R2R) gravure printing; Roughness; Scalability; scalability model; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silver; silver printed electrode; Studies; Surface roughness; Waviness; Widening; Scalability; Roughness; Optimization; scalability model; Roll-to-roll process; Silver; Flexible electrode; Microelectronic fabrication; silver printed electrode; Line width; Printed electronics; Plastics; Cost lowering; roll-to-roll (R2R) gravure printing
• ISSN: 1521-334X; 1558-0822
• DOI: 10.1109/TEPM.2010.2057512

Roll-to-roll (R2R) gravure printing is considered to be a leading technology for the production of flexible and low-cost printed electronics in the near future. To enable the use of R2R gravure in printed electronics, the limits of overlay printing registration accuracy (OPRA) and the scalability of printed features with respect to the physical parameters of the gravure system, including given plastic substrates and inks, should be characterized. Important parameters of printed lines include surface roughness, thickness, line widening, and line-edge roughness. To date, there are no comprehensive reports regarding the limits of OPRA and the scalability of printed electrodes, including the control of surface roughness, thickness, line widening, and line-edge roughness using R2R gravure printing. In this paper, we examine ways of evaluating the OPRA limit of our gravure system. We find that OPRA is limited in the web moving direction to 40 μm and in the perpendicular direction to 16 μm, showing the importance of web handling on registration. Furthermore, we demonstrate the scalability of printed electrodes formed using a R2R gravure system to linewidths of 317 μm, with 440 nm thickness, 30 nm of surface roughness and edge waviness of 4 μm on PET foils, and describe optimization strategies to realize improved surface roughness, thickness, line widening, and line-edge roughness for future printed electronics applications.