M3-Modular Multi-Scale Assembly System for MEMS Packaging

This paper presents recent results in prototyping of a multiscale (macro-micro) robotic assembly platform with modular and reconfigurable characteristics. The system components include precision robots, microstages, end-effectors and fixtures that accomplish assembly tasks in a shared workspace. The system components are systematically characterized in terms of accuracy and repeatability, and assembly plans are performed using kinematic identification, visual servoing, inverse kinematics, and dynamic vibration suppression. As an application packaging problem, various micro and meso scale parts are assembled into a MEMS device. The tolerance budget of assembly ranges from 4 microns to 300 microns, while the size of components in the assembly ranges from 126 microns to 30 mm. Various end-effectors and fixtures have been designed for use with off-the-shelf hardware (robots and microstages) and were tested for precision performance. The robots and the vision system are calibrated to accuracies of 10 microns or less. Inverse kinematics solutions for the robots have been developed in order to position parts in a global coordinate frame. Conclusions are drawn about implementation of calibration, fixturing and visual servoing in order to assemble within the specified tolerance budget