Simulated laser spot enlargement
AssigneeElectro Scientific Industries, Inc.
InventorDonald R. Cutler
Life of this patent
Estimating the term…
Abstract
An fast steering mirror (30), such as a PMN actuated mirror, is positioned in a beam path (18) of a stage-based positioning system (40) to continuously move a laser beam (46) in a high speed prescribed pattern about a nominal target position (60) to spatially separate focused laser spots (48) generated at a high laser repetition rate and thereby create geometric features having dimensions greater than those of the focused laser spot (48). A series of laser spots (48) at a given repetition rate appear as a series of larger diameter laser spots at a lower pulse rate without beam quality problems associated with working out of focus.
Claims22
A method for laser machining an effective kerf width on a work piece with laser output pulses, each of the laser pulses having a laser spot diameter on the work piece that is smaller than the effective kerf width, comprising:
- imparting, from a primary beam positioning system, primary relative movement of a laser spot position to the work piece at a first set of limited velocities and accelerations, the primary beam positioning system providing a beam positioning pathway from a laser to the laser spot position on the work piece, the primary relative movement defining a primary machining path;
- and
- imparting, from a secondary beam positioning system positioned along the beam positioning pathway, secondary relative movement of the laser spot position to the work piece at a second set of velocities and accelerations that are substantially higher than those of the first set, the secondary relative movement being superimposed on the primary relative movement and including a pattern having a pattern dimension, perpendicular to the primary machining path, that is less than or equal to about 15 times the laser spot diameter, the primary and secondary relative movements cooperating to provide the effective kerf width, along the primary machining path, that is generally equal to the pattern dimension plus the spot diameter.
A method for laser machining an effective kerf width on a work piece with laser output pulses, each of the laser pulses having a laser spot diameter on the work piece that is smaller than the effective kerf width, comprising:
- imparting, from a translation stage positioning system, stage-related relative movement of a laser spot position to the work piece at translation stage-limited velocities and accelerations;
- imparting, from a fast positioning system, fast relative movement of the laser spot position to the work piece at fast-limited velocities and accelerations, the fast positioning system having higher acceleration capabilities than the translation stage positioning system;
- integrating the translation stage positioning system and the fast positioning system to impart primary relative movement of the laser spot position to the work piece at a first set of limited velocities and accelerations, the primary beam positioning system providing a beam positioning pathway from a laser to the laser spot position on the work piece, the primary relative movement defining a primary machining path;
- and
- imparting, from a fast steering mirror positioned along the beam positioning pathway, secondary relative movement of the laser spot position to the work piece at a second set of velocities and accelerations that are substantially higher than those of the first set, the secondary relative movement being superimposed on, and nonintegrated with, the primary relative movement and including a pattern having a pattern dimension, perpendicular to the primary machining path, that is less than or equal to about 15 times the laser spot diameter, the primary and secondary relative movements cooperating to provide the effective kerf width, along the primary machining path, that is generally equal to the pattern dimension plus the spot diameter.
Dependencies are inferred from the claim text.