Hybrid Position/Force Fully Closed-Loop Control of a Flip-Chip Soft-Landing Bonding System

Flexure-based bonding system driven by piezoelectric actuator is quite appealing for fulfilling the nanoscale-accuracy and high-efficiency interconnection tasks. However, it turns obstreperous to implement it for high-efficiency and nanoscale-accuracy interconnection during the soft-landing operation, largely because of a large amount of noise in force sensor and low efficiency of traditional controller. To this end, this article presents a novel hybrid position/force fully (HPFF) closed-loop control strategy to enable the developed flip-chip bonding system to run in the manner of nanoscale-accuracy and high-efficiency interconnection. The integrator composed of inertial filter (ICIF) method is proposed to improve the operation efficiency and reduce the time used in the soft-landing process. Besides, the stability of HPFF strategy is demonstrated in theory and numerical calculation. Finally, a series of validation experiments including ICIF comparing experiments, closed-loop trajectory tracking experiments, robustness experiments under different loads and HPFF closed-loop control experiments are successfully implemented. All the results uniformly confirm that the developed flip-chip bonding system has achieved satisfactory soft-landing interconnection performance by taking advantage of the proposed HPFF closed-loop control strategy.