Optimization of Reverse Offset Roll to Plate (RO-R2P) Through Contact Angle

Abstract

The application of 5 μm nano-metal ink pattern has taken center stage for the field of cellular phones, organic solar cell, and so on due to its invisible property and high electrical conductivity. While the non-contact printing, such as ink jet and silk screen printing method, cannot print less than 40 um width pattern, reverse offset printing can control the accuracy of pattern width up to maximum 5 μm. However, due to its direct printing, fracture of final substrate is the biggest problem at the high pressure in the process. Therefore, the following rapid prototyping focuses on optimization of reverse offset printing based on low pressure and optimizing the contact angle as the primary parameters in achieving a high-resolution, 5 μm pattern. This paper proposes the sequence of contact angle (θ) based on the reverse offset printing process as: θ (Stage 1) > θ (Roll) > θ (Stage 2), θ (Stage 3). Through the experiment, a contact angle differential should be 5.4°≤ ∆θ ≤6.4° between roll and Stage 1, ∆θ≤10.1°, between roll and Stage 2, and ∆θ ≤ 13.4° between roll and Stage 3. Whereas the final pattern is not printed or non-continuous when the differential of contact is out of the proposed range, continuous high resolution of 5 μm pattern could be printed when the contact angle range and sequence are optimized as proposed method. Finally, the continuous and high resolution of 5 μm pattern is printed on the Kapton PV9101 when M1 is used for material of roll. Therefore, the continuous high resolution of 5 μm pattern could be produced by optimizing the range of contact angle in the reverse offset system. KeywordsContact Angle; Reverse Offset; Roll to Plate