Patent ID: 6430465
Filing Date: 2002-08-06
Classification: B23K,G03F,G05B,H05K

Abstract:
A positioning system for positioning a tool relative to a target location on a workpiece in response to a positioning command, comprising:a slow positioner for effecting a large range of relative movement between the tool and the workpiece, the slow positioner including a translation stage capable of movement generally along an axis; a fast positioner for effecting small ranges of relative movement between the tool and the workpiece; a positioning signal processor for deriving from the positioning command slow and fast movement-controlling signals; a slow positioner driver for controlling the large range of relative movement of the translation stage in response to the slow movement-controlling signal; a fast positioner driver for controlling the small ranges of relative movement of the fast positioner in response to the fast movement-controlling signal; a pair of spaced-apart displacement sensors in communication with the fast positioner driver and coupled to move with the translation stage along the axis; and a reference surface positioned in proximity to the translation stage and parallel to the axis, the translation stage being capable of moving along the reference surface and the displacement sensors being capable of acquiring information concerning their relative distances from the reference surface and conveying the information to the fast positioner driver to correct for an Abbe error associated with off-axis or rotational movement of the translation stage.