Transparent Electrostatic Clamp For Visual Assembly and Packaging

This paper describes the development of a miniature assembly cell for micro-electromechanical systems (MEMS). Potential applications of the developed assembly cell are assembly of miniature optical systems, integration of optoelectronics, such as laser diodes with CMOS, and epitaxial lift-off (ELO) of thin films used in optoelectronic devices. The cell utilizes a transparent electrostatic gripper and uses several disparate sensing modalities for position control: computer vision for part alignment with respect to the gripper, a fiber-coupled laser, and a position sensitive detector (PSD) for part to assembly alignment. Assembly experiments indicate that the gripping force and stage positioning accuracy are sufficient for insertion of 500µm wide parts in 550 µm wide slots etched in silicon wafers. Details on the cell operation, the control algorithm used and their limitations are also provided