Piezo impact system for printed board sub-micron precision positioning

Summary form only given. A wide range of electronic equipment contains certain components like lenses, heads, mirrors, CCDs, etc., that have to be precisely positioned. For this task two approaches are usual: nudge the part to the correct position manually (only suitable for skilled technicians) or equip the part itself with a micro positioning stage. While the first one requires a long time for fine positioning and eliminates the possibility of a full automatic assembly line, the second one normally needs too much space and a mechanical connection between the part and the stage. In this paper we present a system for positioning printed circuit boards automatically in three degrees of freedom (lateral and longitudinal translation and rotation) with submicron accuracy. No mechanical link exists between the actuators and the board, neither is the board positioned over the actuators. Therefore the board can be pushed but not pulled. The solution involves the use of piezo impact actuators combined with a feedback control system incorporating adaptive control.