A precise position measurement system of roll-to-roll printing using burst alignment patterns

Printed electronics involve a process of creating electrical devices by printing with conductive ink on flexible substrates. This process is environmentally-friendly and affordable, and thus suited for mass production. Roll-to-roll printing is a common method classified under printed electronics. This method uses a roll to apply pressure to film or metallic foil, and prints with conductive ink. To commercialize printed electronic technology using roll-to-roll printing, it is necessary to improve the superposition accuracy. Superposition accuracy refers to the position error between the layers. If the superposition accuracy is poor, the product quality drops due to electrical interference resulting from misalignment. To enhance the superposition accuracy of printed electronics, precise measurements of the web position must initially be obtained. In a previous study, this issue was resolved through the development of a position measurement system for precision alignment. This study improves the web position measurement system of the preceding study by applying a burst alignment pattern. The burst alignment pattern expands the linear measurement range of the optical encoder, and the directions of errors can be determined through signal analysis.