Calibration Systems and Techniques for Automated Microassembly

A calibration technique is presented here that facilitates automated calibration of a robotic system used for open loop MEMS assembly. A micromechanical calibration device was fabricated in a 20 μm thick electro-plated nickel process as well as a 50 μm thick single crystal silicon, deep reactive ion etched (DRIE) process. This device uses a vision sensing system to detect end-effector position. Results obtained using the calibration device, are presented using a microgripper for pick and place assembly. The relative position of the microgripper and die-site was calibrated to an accuracy of ±1 μm using the described techniques. Microgripper geometry obtained using this technique is also ≤ 3.1 μm of the direct measurement. By utilizing these calibration techniques, the assembly system can be automated to yield a cost-effective microassembly solution.