Development of high precision 6-DOF roll printing system for nano contact printing

Abstract

High precision roll printing system is required for next generation lithography. The roll printing system needs alignment of 6 degree of freedom and uniform printing force. In this thesis, high precision 6 degree of freedom roll printing system using magnetic levitation is proposed. To enhance dynamic performance of roll printing system, new Halbach linear active magnetic bearing is proposed. The roll printing system consists of voice coil motor and Halbach linear active magnetic bearing. Each actuators applied Halbach magnet array to reinforce magnetic flux and flux closed loop using steel yoke. To optimize proposed actuators, analytical modeling is performed. Optimization is performed based on analytical modeling. Each actuator optimally designed in constraint. Using optimization results, roll printing system manufactured. To control roll printing system, control algorithm constructed. Six degrees of freedom motion is controlled using kinematics and sensor transform matrix. Various type of sensor used to feedback control. First, to levitate print roll mover, 5 LVDTs and 1 capacitive sensor is used. After levitate print roll mover, control sensor switched to 6 capacitive sensors for high precision. When print roll and substrate roll contact, control switched to force control for uniform printing. The performance of Halbach linear active magnetic bearing was verified. The performance of the roll printing system was verified and its applicability was verified. Evaluation conducted precision and high dynamic performance compare with previous research.