A Flexible Microassembly System for Automated Fabrication of MEMS Sensors

Batch microassembly of MEMS sensors is limited by the manual manipulation required specially trained technicians. To reduce the production costs and simultaneously obtain high production quality, a flexible microassembly system for automated bonding of MEMS sensors is developed. The system consists of a set of autonomous modules that can adapt their structures and functions to various sizes of MEMS sensors, including positioning stages, a microscopy imaging system, a flexible micromanipulator, a heater, a fixture, a supply station and auxiliary systems. Optomechatronic design is essential to the development of integrated systems due to the basic importance of microscope optics to microassembly. In this paper, major methodology issues in optomechatronic design of this system are introduced. A wavelet-based microscopic focus measure and a control scheme with a modified Smith predicator to decrease the inherent time delay of vision system are presented. A smart force sensor with one dimension is employed to sense and control the interactive force. To perform manipulations automatically, a control system, including a task planning level and a real-time execution level, is developed. The productivity of the flexible microassembly system is validated by further experiments