US 5,751,585 AGranted

High speed, high accuracy multi-stage tool positioning system

AssigneeElectro Scientific Industries, Inc.

InventorsDonald R. Cutler, Robert M. Pailthorp, Mark A. Unrath

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Abstract

A multi-rate positioner system (50) receives unpanelized positioning commands from a database storage subsystem (64), profiles the commands (72) into a half-sine positioning signal, and further processes the signal into a low-frequency positioning signal (LFP) and a high-frequency positioning signal (HFP) for actuating respective slow (56, 58) and fast (54) positioners to target locations on a workpiece (62). The slow and fast positioners move without necessarily stopping in response to a stream of positioning command data while coordinating their individually moving positions to produce temporarily stationary tool positions (140) over target locations defined by the database. The multi-rate positioning system reduces the fast positioner movement range requirement while providing significantly increased tool processing throughput.

Claims22

Dependent claims

In a tool positioning system that is implemented as part of a workpiece processing system in which the workpiece is an electronic device or an electronic device package, the tool position system positioning a tool relative to a set of target locations and describing a tool path on a workpiece in response to a set of positioning commands, comprising:

a first positioner stage effecting at a first positioning acceleration a controlled first range of relative movement between the tool and the workpiece;
a second positioner stage effecting at a second positioning acceleration a controlled second range of relative movement between the tool and the workpiece, the second controlled range of relative movement being greater than the first controlled range of relative movement, and the second positioning acceleration being less than the first positioning acceleration;
a signal processor deriving from the set of positioning commands a movement-controlling signal;
a filter receiving the movement-controlling signal and separating it to produce higher bandwidth and lower bandwidth positioning signals that have an inherent delay offset between them;
a delay element introducing a delay to compensate for the inherent delay offset between the higher bandwidth and lower bandwidth positioning signals;
and
first and second positioner drivers responsive to the delay compensated higher bandwidth and lower bandwidth positioning signals to drive the respective first and second positioner stages so that they respond by operating within their controlled ranges of relative movement with at least partly uninterrupted concurrent motion in a coordinated fashion to produce accurate tool positioning along the tool path.

4 more elements

In a tool positioning system that is implemented as part of a workpiece processing system in which the workpiece is an electronic device or an electronic device package, the tool positioning system including a first positioner that effects at a first positioning acceleration a controlled first range of relative movement between a tool and the workpiece and a second positioner that effects at a second positioning acceleration a controlled second range of relative movement between the tool and the workpiece, the second controlled range of relative movement being greater than the first controlled range of relative movement and the second positioning acceleration being less than the first positioning acceleration, a method of coordinating the operation of the first and second positioners to minimize displacement imparted by the first positioner relative to that imparted by the second positioner within the respective first and second controlled ranges of relative movement as the first and second positioners concurrently move and selectively position the tool relative to a set of target locations and describe a tool path on the workpiece, comprising:

providing positions commands that define a tool path along which a tool is to be directed at controlled accelerations;
generating from the positioning commands higher bandwidth and lower bandwidth positioning signals that have an inherent delay offset between them;
deriving from the higher bandwidth and lower bandwidth positioning signals respective first and second positioning signals including a compensation delay to compensate for the inherent delay offset between the higher bandwidth and lower bandwidth positioning signals;
and
deriving from the first and second positioning signals first and second drive signals and applying the first and second drive signals to the respective first and second positioners so that they respond by operating within their controlled ranges of relative movement with at least partly uninterrupted concurrent motion in a coordinated fashion to produce accurate tool positioning along the tool path at the controlled accelerations.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/615,049Filed 12 Mar 1996 · continuation in part
Priority: 20 Mar 1995
Granted: 12 May 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification21 codes

B23K 26/083
Devices involving relative movement between laser beam and workpiece: devices involving movement of the workpiece in at least one axial direction
B23K 26/082
Devices involving relative movement between laser beam and workpiece: scanning systems, i.e. devices involving movement of the laser beam relative…
B23K 26/0876
Devices involving movement of the laser head in at least one axial direction: in at least two axial directions
G05B 19/39
Characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement…:…