Register Marks Position Measurement System to Numerically Evaluate the Fidelity of Engraved Pattern Position in a Printing Roll

Printed electronics is a manufacturing technology that fabricates electronic devices using printing techniques. Due to its characteristics of low cost and simple process, a roll-to-roll printing technique has been used to achieve the large area and mass production of flexible electronic devices such as a thin film transistor. In the roll-to-roll printing process, a fidelity of the engraved pattern position is one of the most important techniques to fabricate high resolution multi-layer electronic devices. In this study, an engraved register mark position measurement system was developed to numerically evaluate the position accuracy of engraved mark in printing roll. The proposed system is based on a high-precision encoder based position control system and a high-resolution machine vision system. The measurement error of the developed system is within the camera resolution ±2.1 μm, verifying the superiority of the system. Using the developed system, we measured the position errors of the engraved register marks for six industrial scale printing rolls. This study suggests that the position error of the engraved mark should be considered to achieve a high precision register control below ±10 μm and necessity of the developed system.