Laser processing systems using through-the-lens alignment of a laser beam with a target feature
First Claim
1. A method for aligning a processing laser beam to workpiece features, the processing laser beam comprising a predetermined wavelength for processing the workpiece features, the method comprising:
- propagating the processing laser beam along a propagation path through a scan lens to a workpiece;
manipulating the processing laser beam so as to illuminate, through the scan lens, a selected region of the workpiece comprising an alignment target with the manipulated processing laser beam at the predetermined wavelength, wherein the selected region is larger than a reference laser beam spot of the processing laser beam provided through the scan lens;
directing at least a portion of a reflection of the manipulated processing laser beam back through the scan lens to a camera for imaging the selected region of the workpiece; and
based on an image of the selected region captured by the camera, determining a position of the reference laser beam spot relative to the alignment target.
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Accused Products
Abstract
A laser processing system for micromachining a workpiece includes a laser source to generate laser pulses for processing a feature in a workpiece, a galvanometer-driven (galvo) subsystem to impart a first relative movement of a laser beam spot position along a processing trajectory with respect to the surface of the workpiece, and an acousto-optic deflector (AOD) subsystem. The AOD subsystem may include a combination of AODs and electro-optic deflectors. The AOD subsystem may vary an intensity profile of laser pulses as a function of deflection position along a dither direction. The AOD subsystem may be used for aligning a processing laser beam to workpiece features.
64 Citations
15 Claims
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1. A method for aligning a processing laser beam to workpiece features, the processing laser beam comprising a predetermined wavelength for processing the workpiece features, the method comprising:
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propagating the processing laser beam along a propagation path through a scan lens to a workpiece; manipulating the processing laser beam so as to illuminate, through the scan lens, a selected region of the workpiece comprising an alignment target with the manipulated processing laser beam at the predetermined wavelength, wherein the selected region is larger than a reference laser beam spot of the processing laser beam provided through the scan lens; directing at least a portion of a reflection of the manipulated processing laser beam back through the scan lens to a camera for imaging the selected region of the workpiece; and based on an image of the selected region captured by the camera, determining a position of the reference laser beam spot relative to the alignment target. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A laser processing system for aligning a processing laser beam to workpiece features, the processing laser beam comprising a predetermined wavelength for processing the workpiece features, the system comprising:
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a laser source for providing the processing laser beam; a scan lens to focus the processing laser beam at a laser beam spot on or in the workpiece; an acousto-optic deflector (AOD) subsystem to; generate a raster pattern of laser beam spots that illuminates a selected region of the workpiece, through the scan lens, with a uniform fluence, wherein the selected region includes an alignment target; and provide, through the scan lens, the reference laser beam spot within the selected region, wherein the reference laser beam spot is at a higher intensity than that of the raster pattern of laser beam spots; optical elements to direct at least a portion of a reflection of the processing laser beam from the selected region back through the scan lens; and a camera for imaging the selected region of the workpiece, wherein the image of the selected region is used to determine a position of the reference laser beam spot relative to the alignment target. - View Dependent Claims (10, 11)
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12. A system for aligning a processing laser beam to workpiece features, the processing laser beam comprising a predetermined wavelength for processing the workpiece features, the method comprising:
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means for propagating the processing laser beam along a propagation path through a scan lens to a workpiece; means for manipulating the processing laser beam so as to illuminate, through the scan lens, a selected region of the workpiece comprising an alignment target with the manipulated processing laser beam at the predetermined wavelength, wherein the selected region is larger than a reference laser beam spot of the processing laser beam provided through the scan lens; means for directing at least a portion of a reflection of the manipulated processing laser beam back through the scan lens to a camera for imaging the selected region of the workpiece; and means for determining, based on an image of the selected region captured by the camera, a position of the reference laser beam spot relative to the alignment target. - View Dependent Claims (13, 14, 15)
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Specification