Enhancement of printing overlay accuracy by reducing the effects of mark deformations

Abstract

The roll-based high-speed printing process has the two major advantages of high productivity and a simple process over the conventional electronic device manufacturing process. There have been several attempts to commercially apply the roll-based high-speed printing process to various electronic devices. While such attempts have sought to improve the performance of electronic devices, these devices require multi-layered structures to be printed with high overlay accuracy between each layer. Printed patterns always appear to be deformed compared to the designs on the master plate because the printing process is solution based. Given variations in ink transfer volume, the accuracy of the overlay measurement can be degraded by mark deformations. This means that these deformations caused by the printing mechanism should be taken into account. In this paper, we provide the details from a simulation study and experiment carried out using gravure offset printing to investigate the effects of mark deformations on overlay measurement accuracy. We analyzed and optimized the pattern registration algorithms and the type of overlay marks in order to improve the measurement accuracy of the positions of the printed patterns. As a result, the repeatability measuring the positions of the printed patterns can be reduced to 1.0μm and 2.0μm in the CD and MD directions in the gravure offset printing process, respectively.