Abstract: Preferred embodiments of the invention implement techniques for modifying the command trajectory, the architecture of a servomechanism control system, or both, to reduce the servo error during and/or after the command trajectory. An iterative refinement procedure generates for use by the servomechanism control system a corrective input, du, which significantly reduces the error between the desired and actual servomechanism control system outputs. In one embodiment, a uniquely identified plant model is employed in the iterative refinement procedure to compute an approximate gradient that improves the performance and reliability of the refinement procedure. In another embodiment, the actual plant response is used in place of the identified model in the iterative refinement procedure. This is accomplished by time-reversing the stored error signal from a training run, before applying it to the plant to generate an update to the corrective input signal du.

Abstract: A method and system increase the quality of results achieved by laser micromachining systems. Data relating to parameters controlling laser micromachining process are recorded during the micromachining process, identified by the feature associated with the parameters used to micromachine, and stored on the system. The stored data can be either retrieved during the micromachining process to enable real time control or retrieved after workpiece processing to conduct statistical process control.

Abstract: A method and system increase the quality of results achieved by laser micromachining systems. Data relating to parameters controlling laser micromachining process are recorded during the micromachining process, identified by the feature associated with the parameters used to micromachine, and stored on the system. The stored data can be either retrieved during the micromachining process to enable real time control or retrieved after workpiece processing to conduct statistical process control.

Abstract: A method and system for increasing throughput of laser micromachining systems use more than one laser. Two or more pulsed laser beams are combined and then separated into multiple laser beams that enable the system to work simultaneously at multiple locations on the workpiece with pulse rates greater than those achievable with independently operating lasers while maintaining pulse energy equal to or greater than the pulse energy of each of the original independent laser beams. Most laser micromachining applications required multiple sequential pulses to process a workpiece. Increasing the pulse rate while maintaining pulse energy effects more rapid material removal and thereby increases throughput for a laser micromachining system.

Abstract: High speed removal of material from a specimen employs a beam positioner for directing a laser beam axis along various circular and spiral laser tool patterns. A preferred method of material removal entails causing relative movement between the axis of the beam and the specimen, directing the beam axis at an entry segment acceleration and along an entry trajectory to an entry position within the specimen at which laser beam pulse emissions are initiated, moving the beam axis at a circular perimeter acceleration within the specimen to remove material along a circular segment of the specimen, and setting the entry segment acceleration to less than twice the circular perimeter acceleration.

Abstract: Preferred embodiments of the invention implement techniques for modifying the command trajectory, the architecture of a servomechanism control system, or both, to reduce the servo error during and/or after the command trajectory. An iterative refinement procedure generates for use by the servomechanism control system a corrective input, du, which significantly reduces the error between the desired and actual servomechanism control system outputs. In one embodiment, a uniquely identified plant model is employed in the iterative refinement procedure to compute an approximate gradient that improves the performance and reliability of the refinement procedure. In another embodiment, the actual plant response is used in place of the identified model in the iterative refinement procedure. This is accomplished by time-reversing the stored error signal from a training run, before applying it to the plant to generate an update to the corrective input signal du.

Abstract: Laser pulse energy adjustments are motivated by an understanding of the effect of laser pulse width variations among different lasers on satisfying a quality metric associated with a laser-processed target. In a preferred embodiment, the adjustments normalize this effect among different lasers drilling vias in a target specimen. The number of pulses delivered to the target specimen to form each via can be modified, based on the pulse energy applied to the via location, to control different via quality metrics.

Abstract: A laser beam switching system employs a laser coupled to a beam switching device that causes a laser beam to switch between first and second beam positioning heads such that while the first beam positioning head is directing the laser beam to process a workpiece target location, the second beam positioning head is moving to another target location and vice versa. A preferred beam switching device includes first and second AOMs positioned such that the laser beam passes through the AOMs without being deflected. When RF is applied to the first AOM, the laser beam is diffracted toward the first beam positioning head, and when RF is applied to the second AOM, the laser beam is diffracted toward the second beam positioning head.

Abstract: Laser beam positioners (300, 340) employ a steering mirror (236, 306) that performs small-angle deflection of a laser beam (270) to compensate for cross-axis (110) settling errors of a positioner stage (302). A two-axis mirror is preferred because either axis of the positioner stages may be used for performing work. In one embodiment, the steering mirror is used for error correction only without necessarily requiring coordination with the positioner stage position commands. A fast steering mirror employing a flexure mechanism and piezoelectric actuators to tip and tilt the mirror is preferred in semiconductor link processing (“SLP”) applications. This invention compensates for cross-axis settling time, resulting in increased SLP system throughput and accuracy while simplifying complexity of the positioner stages because the steering mirror corrections relax the positioner stage servo driving requirements.

Abstract: Laser beam positioners (300, 340) employ a steering mirror (236, 306) that performs small-angle deflection of a laser beam (270) to compensate for cross-axis (110) settling errors of a positioner stage (302). A two-axis mirror is preferred because either axis of the positioner stages may be used for performing work. In one embodiment, the steering mirror is used for error correction only without necessarily requiring coordination with the positioner stage position commands. A fast steering mirror employing a flexure mechanism and piezoelectric actuators to tip and tilt the mirror is preferred in semiconductor link processing (“SLP”) applications. This invention compensates for cross-axis settling time, resulting in increased SLP system throughput and accuracy while simplifying complexity of the positioner stages because the steering mirror corrections relax the positioner stage servo driving requirements.