Design and test of a compliant controller using piezoelectric-actuated compliant mechanisms

Abstract In the field of semiconductor manufacturing, the demand for high-precision force-position control is increasingly prominent. Single-position control or force control can hardly meet the requirements of practical production. Although compliant controllers based on rigid mechanisms are capable of realizing simultaneous force-position control, they are unfortunately limited to millimeter-scale position control and newton-scale force control, exhibiting inadequate control precision. To meet the demand for high-precision force-position coordinated control in nanoindentation and mini LED needle-based chip transfer applications within the semiconductor manufacturing process. This paper proposes a high-precision active compliant controller based on the compliant mechanism (CM). Two piezoelectric-actuated CMs (PEA-CMs) are designed. Capacitive displacement sensors and force sensors are mounted in two CMs. The static and dynamic performance of the two CMs was analyzed. The theoretical calculation results were verified by the simulation. The system models of the two PEA-CMs were built. Force, position, and compliant controllers were used to control two PEA-CMs, respectively. Two prototype systems using the proposed PEA-CM-based dual-loop compliant controllers were established. The performance of the two PEA-CMs was tested. Depth-sensing indentation and mini-LED needling tests were performed. Performance was evaluated using a microscope vision system, a white-light interferometer, and a laser-confocal microscope. Test results show that the PEA-CM-based compliant controller performs better. The proposed PEA-CM-based compliant controller helps to flexibly control the end-effector during indentation and needling tasks.