A supervisory wafer-level 3D microassembly system for hybrid MEMS fabrication

Hybrid MEMS (microelectromechanical systems) integrate solid-state ICs with MEMS sensors and actuators. It is widely believed that such systems will bring fundamental technological impacts and significant social benefits. Hybrid MEMS manufacturing requires the development of new fabrication, packaging and interconnection technologies in which microassembly plays a critical role. Microassembly is the assembly of objects with microscale and/or mesoscale* features under microscale tolerances. It integrates techniques from many different areas such as robotics, computer vision, microfabrication and surface science. This paper studies the design and implementation of microassembly systems through the introduction of a supervisory microassembly workcell. This workcell is developed for 3D assembly of large numbers of micromachined thin metal parts into DRIE (deep reactive ion etching) etched holes in silicon wafers. It overcomes a major limitation of current MEMS fabrication techniques by allowing the use of incompatiable materials and fabrication processes to build complex-shaped 3D MEMS structures. The system is able to perform reliable and efficient wafer-level microassembly operations within a supervisory framework. Microassembly brings new and unique issues to robotics research. The major components of microassembly systems are analyzed. Results on micromanipulator design, illumination modeling and control, and microgripper design are presented.