Effect of process parameters on fidelity of printed line width in high resolution roll-to-roll gravure printing

Abstract

Recently, printing pattern in high resolution (line width <20 µm) has been given a great interest in the field of printed electronics for application of organic photovoltaic and fast integrated circuits. Improving the grid electrode could reduce the optical loss and the resistance loss thereby increasing conversion efficiency of solar cells. For higher performance transistors, it is necessary to scale channel length below 10 µm to achieve MHz operations. To enable to build up pattern with high fidelity demands a study on the effect of process parameters in gravure printing. In this paper, a mathematical model is proposed to analyze the mechanism of the ink spreading on the substrate based on squeezing flow theory between parallel plates. It was proven that process parameters such as nip force, printing speed and viscosity of ink are significant factors contributing to the resulting printed line width. Finally, the experimental investigation on the effect of such parameters demonstrated that a high printing speed, low nip force and high viscosity of ink could decrease the ink spreading thereby gaining high fidelity. This work could be utilized as a guideline to set up the operating conditions to maintain the fidelity of printed line width in high resolution roll-to-roll gravure printing.