Laser segmented cutting

Abstract

UV laser cutting throughput through silicon and like materials is improved by dividing a long cut path ( 112 ) into short segments ( 122 ), from about 10 μm to 1 mm. The laser output ( 32 ) is scanned within a first short segment ( 122 ) for a predetermined number of passes before being moved to and scanned within a second short segment ( 122 ) for a predetermined number of passes. The bite size, segment size ( 126 ), and segment overlap ( 136 ) can be manipulated to minimize the amount and type of trench backfill. Real-time monitoring is employed to reduce rescanning portions of the cut path 112 (112) where the cut is already completed. Polarization direction of the laser output ( 32 ) is also correlated with the cutting direction to further enhance throughput. This technique can be employed to cut a variety of materials with a variety of different lasers and wavelengths. A multi-step process can optimize the laser processes for each individual layer.

1. A method of increasing throughput in a laser cutting process, comprising:
 directing a first pass of first laser pulses to impinge along a first segment of a cutting path having a cutting path length greater than 100 μm, each first laser pulse having a first spot area on a workpiece, the first segment having a first segment length that is longer than the first spot area and shorter than the cutting path length;   directing a second pass of second laser pulses to impinge along a second segment of the cutting path, each second laser pulse having a second spot area on the workpiece, the second segment having a second segment length that is longer than the second spot area and shorter than the cutting path length, the second segment overlapping the first segment by an overlap length greater than at least the first or second spot areas; and   after directing at least the first and second passes of laser pulses, directing a third pass of third laser pulses to impinge along a third segment of the cutting path, each third laser pulse having a third spot area on the workpiece, the third segment having a third segment length that is longer than the third spot area and shorter than the cutting path length, the third segment including a subsequent portion of the cutting path other than the first or second segments, wherein the subsequent portion of the cutting path has a nonoverlap length greater than the first, second, or third spot areas.   
     
     
       2. The method of  claim 1  in which major portions of the first and second segments overlap. 
     
     
       3. The method of  claim 1  in which the second segment includes the first segment. 
     
     
       4. The method of  claim 3  in which the first and second segments are processed in a same direction. 
     
     
       5. The method of  claim 3  in which the first and second segments are processed in opposite directions. 
     
     
       6. The method of  claim 1  in which the first and second segments are processed in a same direction. 
     
     
       7. The method of  claim 1  in which the first and second segments are processed in opposite directions. 
     
     
       8. The method of  claim 1  in which additional sets of first and/or second laser pulses are applied to the first and/or second segments to form a through trench within the first and/or second segments prior to applying the third laser pulses. 
     
     
       9. The method of  claim 1  further comprising:
 forming a through trench in the first and/or second segments prior to applying the third laser pulses. 
 
     
     
       10. The method of  claim 1  further comprising:
 forming a through trench in the first and/or second segments with multiple passes of laser pulses prior to applying the third laser pulses; and 
 forming a through trench within the third segment. 
 
     
     
       11. The method of  claim 10  further comprising:
 forming a through trench along the entire cutting path length. 
 
     
     
       12. The method of  claim 11  in which the cutting path length is greater than 1 mm and the first, second, and third segment lengths are between about 10 μm and about 500 μm. 
     
     
       13. The method of  claim 1  in which the cutting path length is greater than 1 mm and the first, second, and third segment lengths are between about 10 μm and about 500 μm. 
     
     
       14. The method of  claim 13  in which the cutting path length is greater than 10 mm and the first, second, and third segment lengths are between about 200 μm and about 500 μm. 
     
     
       15. The method of  claim 13  in which the first, second, and third laser pulses are characterized by a UV wavelength, a pulse repetition frequency of greater than 5 kHz, pulse energies of greater than 200 μJ, and a bite size of about 0.5 to about 50 μm. 
     
     
       16. The method of  claim 1  in which the first, second, and third laser pulses are characterized by a UV wavelength, a pulse repetition frequency of greater than 5 kHz, pulse energies of greater than 200 μJ, and a bite size of about 0.5 to about 50 μm. 
     
     
       17. The method of  claim 16  in which the workpiece has a thickness greater than 50 μm. 
     
     
       18. The method of  claim 17  in which the workpiece has a thickness greater than 500 μm. 
     
     
       19. The method of  claim 12  in which the workpiece has a thickness greater than 50 μm. 
     
     
       20. The method of  claim 12  in which the workpiece has a thickness greater than 500 μm, the cutting path length is greater than 100 mm, and the throughcut along the entire length of the cutting path is made with fewer than 25 passes of laser pulses over any position along the cutting path. 
     
     
       21. The method of  claim 13  in which the workpiece has a thickness greater than 200 μm, further comprising:
 cutting through the entire thickness along the cutting path at a cutting speed of greater than 10 mm per minute. 
 
     
     
       22. The method of  claim 21  in which a major portion of the thickness of the workpiece comprises a semiconductor material, a glass material, a ceramic material, or a metallic material. 
     
     
       23. The method of  claim 21  in which a major portion of the thickness of the workpiece comprises Si, GaAs, SiC, SiN, indium phosphide, or AlTiC. 
     
     
       24. The method of  claim 22  in which the laser pulses are generated from a solid-state laser or a CO 2  laser. 
     
     
       25. The method of  claim 1  in which the laser pulses are generated from a solid-state laser or a CO 2  laser. 
     
     
       26. The method of  claim 2  in which the overlap length of the first and second portions or the first or second segment lengths are sufficiently short such that the second laser pulses impinge along the overlap length before a major portion of any debris generated by the first laser pulses cools along the overlap length to ambient temperature. 
     
     
       27. The method of  claim 1  in which the third segment excludes the first or second segments. 
     
     
       28. The method of  claim 1  in which the first laser pulses impinge along the cutting path in a first cutting direction and the first laser pulses have a first polarization orientation that is parallel to the first cutting direction, in which the third laser pulses impinge along the cutting path in a third cutting direction and the third laser pulses have a third polarization orientation that is parallel to the third cutting direction, and in which the first and third cutting directions are transverse. 
     
     
       29. The method of  claim 28  further comprising:
 employing a polarization control device to change from the first polarization orientation to the third polarization orientation. 
 
     
     
       30. The method of  claim 10  further comprising:
 monitoring throughcut status with a throughcut monitor to determine throughcut positions where throughcuts have been affected along the cutting path; and 
 reducing impingement of the throughcut positions during the passes of first, second, third, or subsequent laser pulses in response to information provided by the throughcut monitor. 
 
     
     
       31. The method of  claim 1  in which the laser pulses within the first pass have generally similar parameters. 
     
     
       32. The method of  claim 1  in which the laser pulses of the first, second, and third passes have generally similar parameters. 
     
     
       33. The method of  claim 1  in which the laser pulses of at least two of the first, second, and third passes have at least one generally different parameter. 
     
     
       34. The method of  claim 1  in which at least two of the laser pulses in at least one of the first, second, or third passes have at least one generally different parameter. 
     
     
       35. The method of  claim 1  in which multiple passes of laser pulses are applied to the first segment to form a throughcut within the first segment. 
     
     
       36. The method of  claim 35  in which the throughcut is formed in the first segment before the pass of second laser pulses is applied to the second segment. 
     
     
       37. The method of  claim 36  in which multiple passes of laser pulses are applied to the second segment to form a throughcut within the second segment. 
     
     
       38. The method of  claim 37  in which the throughcut is formed in the second segment before the pass of third laser pulses is applied to the third segment. 
     
     
       39. The method of  claim 38  in which multiple passes of laser pulses are applied to subsequent segments to sequentially form throughcuts within the respective subsequent segments to form a full length throughcut along the cutting path length. 
     
     
       40. The method of  claim 1  in which only minor portions of the first and second segments overlap. 
     
     
       41. The method of  claim 1  in which the first laser pulses impinge along the cutting path in a first cutting direction and the first laser pulses have a first polarization orientation that is oriented to the first cutting direction to enhance throughput or cut quality, in which the third laser pulses impinge along the cutting path in a third cutting direction and the third laser pulses have a third polarization orientation that is oriented to the third cutting direction to enhance throughput or cut quality, and in which the first and third cutting directions are transverse and the first and third polarization orientations are transverse. 
     
     
       42. The method of  claim 1  in which at least one of the segments is an arc. 
     
     
       43. The method of  claim 1  in which a purge gas is employed to facilitate blowing potential backfill debris through throughcuts along the cutting path. 
     
     
       44. The method of  claim 1  in which an elongated laser pass that includes at least three first, second, and third segments is applied to the cutting path. 
     
     
       45. The method of  claim 1  in which each spot area along a segment is in proximity to or partly overlaps the spot area of a preceding laser pulse. 
     
     
       46. A method of increasing throughput for forming a cut along a cutting path having a cutting path length on a workpiece, comprising:
 selecting a segment length that is shorter than the cutting path length;   directing a first pass of first laser pulses having first spot areas to impinge the workpiece along a first segment of about the segment length along the cutting path;   directing a second pass of second laser pulses having second spot areas to impinge the workpiece along a second segment of about the segment length along the cutting path, the second segment overlapping the first segment by an overlap length greater than at least the first or second spot areas; and   after directing at least the first and second passes of laser pulses, directing a third pass of third laser pulses having third spot areas to impinge along a third segment of about the segment length along the cutting path, the third segment including a portion of the cutting path that extends beyond the first or second segments, wherein the portion of the cutting path has a portion length greater than the first, second, or third spot areas.   
     
     
       47. The method of  claim 46  in which impingement of laser pulses along the cutting path generates debris and in which the overlap length or the segment length is sufficiently short such that the second pass of second laser pulses impinge along the overlap length before a major portion of any debris generated by the first laser pulses cools to ambient temperature along the overlap length. 
     
     
       48. A method of increasing throughput in a laser cutting process, comprising:
 directing a first pass of first laser pulses to impinge along a first segment of a cutting path having a cutting path length, each first laser pulse having a first spot area on a workpiece, the first segment having a first segment length that is longer than the first spot area and shorter than the cutting path length;   directing second passes of second laser pulses to impinge along a second segment of the cutting path, the second segment including an overlap length that overlaps at least a portion of the first segment until a throughcut is made within the overlap length, each second laser pulse having a second spot area on a workpiece, the second segment having a second segment length that is longer than the second spot area and shorter than the cutting path length, the overlap length being greater than at least the first or second spot areas; and   after directing at least the first and second passes of laser pulses, directing third passes of third laser pulses to impinge along a third segment of the cutting path until a throughcut is made within the third segment, each third laser pulse having a third spot area on a workpiece, the third segment having a third segment length that is longer than the third spot area and shorter than the cutting path length, the third segment including a portion of the cutting path that extends beyond the first or second segments, wherein the portion of the cutting path has a portion length greater than the first, second, or third spot areas.   
     
     
       49. The method of  claim 1  in which the overlap length of the first and second portions or the first or second segment lengths are in a range appropriate so as to exploit with second laser pulses persistence of a selected transient effect arising from the interaction of first pulses with the workpiece along the overlap length. 
     
     
       50. The method of  claim 46  in which the overlap length of the first and second portions or the first or second segment lengths are in a range appropriate so as to exploit with second laser pulses persistence of a selected transient effect arising from the interaction of first pulses with the workpiece along the overlap length. 
     
     
       51. The method of  claim 48  in which the overlap length of the first and second portions or the first or second segment lengths are in a range appropriate so as to exploit with second laser pulses persistence of a selected transient effect arising from the interaction of first pulses with the workpiece along the overlap length. 
     
     
       52. A method of laser processing a workpiece including an electronic device having a wafer substrate, the electronic device having an edge formed from first and second transverse surfaces, comprising:
 directing to the workpiece a primary group of passes of primary laser pulses to impinge locations along a primary segment of a cutting path that is continuous and has a cutting path length, each primary laser pulse having a primary spot area that defines a primary spatial major axis on the workpiece and impinging a location along the primary segment, the primary segment having a primary segment length that is longer than the primary spatial major axis and shorter than the cutting path length, and at least some of the locations along the primary segment length being impinged multiple times by the primary laser pulses of the primary group of passes;   directing to the workpiece a secondary group of passes of secondary laser pulses to impinge locations along a secondary segment of the cutting path, each secondary laser pulse having a secondary spot area that defines a secondary spatial major axis on the workpiece and impinging a location along the secondary segment, the secondary segment having a secondary segment length that is longer than the secondary spatial major axis and shorter than the cutting path length, and at least some of the locations along the secondary segment length being impinged multiple times by the secondary laser pulses of the secondary group of passes, the secondary segment overlapping the primary segment by an overlap length greater than at least the primary or secondary spatial major axes; and   after directing to the workpiece at least the primary and secondary groups of passes of respective primary and secondary laser pulses, directing to the workpiece a tertiary group of passes of tertiary laser pulses to impinge locations along a tertiary segment of the cutting path, each tertiary laser pulse having a tertiary spot area that defines a tertiary spatial major axis on the workpiece and impinging a location along the tertiary segment, the tertiary segment having a tertiary segment length that is longer than the tertiary spatial major axis and shorter than the cutting path length, and at least some of the locations along the tertiary segment length being impinged multiple times by the tertiary laser pulses of the tertiary group of passes, the tertiary segment including a subsequent portion of the cutting path other than the primary or secondary segments, wherein:   the subsequent portion of the cutting path has a nonoverlap length greater than any one of the primary, secondary, and tertiary spatial major axes;   at least one of the primary, secondary, and tertiary groups of passes of respective primary, secondary, and tertiary laser pulses comprises multiple pulses of laser output that propagate along a beam axis, the laser output having a wavelength and the multiple pulses including first, second, and third consecutive laser pulses generated at a repetition rate;   a beam positioning system imparts relative motion of the electronic device and the beam axis;   the laser output is directed toward the first surface in proximity to the edge of the electronic device, such that the first, second, and third consecutive laser pulses impinge the first surface with respective first, second, and third spot areas to contribute to formation of a trim line along the cutting path; and   control of the relative motion is coordinated with the repetition rate such that the second spot area partly overlaps the first spot area and impinges a first nonoverlapping area having a first nonoverlap spatial major axis of 0.5-9 μm and such that the third spot area partly overlaps the second spot area and impinges a second nonoverlapping area having a second nonoverlap spatial major axis of 0.5-9 μm, thereby converting the edge to a rounded edge along the trim line.   
     
     
       53. The method of claim 52 in which the first and second nonoverlapping areas comprise a spatial major axis of 1-7 μm. 
     
     
       54. The method of claim 52 in which the rounded edge comprises a radius of curvature of about 5-50 μm. 
     
     
       55. The method of claim 54 in which the rounded edge comprises a radius of curvature of about 5-25 μm. 
     
     
       56. The method of claim 52 in which the first and second laser outputs each have peak power density of greater than 500 MW/cm 2 . 
     
     
       57. The method of claim 52 in which the spot areas each comprise a spatial major axis of about 5-25 μm. 
     
     
       58. The method of claim 52 in which the laser pulses comprise an energy density of greater than about 50 J/cm 2  per pulse. 
     
     
       59. The method of claim 58 in which the laser pulses comprise an energy density of about 200-1100 J/cm 2  per pulse. 
     
     
       60. The method of claim 52 in which the repetition rate is greater than about 5 kHz. 
     
     
       61. The method of claim 52 in which at least one of the laser pulses is generated by a holmium or erbium-doped laser. 
     
     
       62. The method of claim 52 in which the first surface or second surface comprises an air-bearing surface of a magnetic head. 
     
     
       63. The method of claim 52 in which only a portion of the first spot area impinges the first surface and only a portion of the second spot area impinges the first surface. 
     
     
       64. The method of claim 63 in which the spot areas have centers, and the centers of the spot areas are directed at the edge. 
     
     
       65. The method of claim 52 in which the electronic device has a device depth transverse to the first or second surface, further comprising:
 forming the edge to an edge depth that is less than the device depth with a mechanical dicing blade prior to generating the laser output.   
     
     
       66. The method of claim 65 further comprising:
 extending the edge depth to equal the device depth with a mechanical dicing blade subsequent to generating the laser output.   
     
     
       67. The method of claim 52 in which the rounded edge has a radius of curvature, further comprising:
 directing the laser output to form multiple adjacent or overlapping substantially parallel trim lines to modify the radius of curvature of the rounded edge.   
     
     
       68. The method of claim 52 in which the rounded edge has a radius of curvature, further comprising:
 directing the laser output and coordinating control of the relative motion with the repetition rate to apply one or more adjacent or overlapping substantially parallel trim lines to shape the radius of curvature of the rounded edge.   
     
     
       69. The method of claim 52 in which the surfaces comprise AlTiC or vacuum-deposited alumina. 
     
     
       70. The method of claim 52 in which the surfaces comprise silicon, silicon carbide, or titanium carbide. 
     
     
       71. The method of claim 52 in which the electronic device is a slider. 
     
     
       72. A method of laser processing a workpiece including a wafer substrate including a brittle, high melting temperature ceramic or glass target material having a surface, comprising:
 directing to the workpiece a primary group of passes of primary laser pulses to impinge locations along a primary segment of a cutting path that is continuous and has a cutting path length, each primary laser pulse having a primary spot area that defines a primary spatial major axis on the workpiece and impinging a location along the primary segment, the primary segment having a primary segment length that is longer than the primary spatial major axis and shorter than the cutting path length, and at least some of the locations along the primary segment length being impinged multiple times by the primary laser pulses of the primary group of passes;   directing to the workpiece a secondary group of passes of secondary laser pulses to impinge locations along a secondary segment of the cutting path, each secondary laser pulse having a secondary spot area that defines a secondary spatial major axis on the workpiece and impinging a location along the secondary segment, the secondary segment having a secondary segment length that is longer than the secondary spatial major axis and shorter than the cutting path length, and at least some of the locations along the secondary segment length being impinged multiple times by the secondary laser pulses of the secondary group of passes, the secondary segment overlapping the primary segment by an overlap length greater than at least the primary or secondary spatial major axes; and   after directing to the workpiece at least the primary and secondary groups of passes of respective primary and secondary laser pulses, directing to the workpiece a tertiary group of passes of tertiary laser pulses to impinge locations along a tertiary segment of the cutting path, each tertiary laser pulse having a tertiary spot area that defines a tertiary spatial major axis on the workpiece and impinging a location along the tertiary segment, the tertiary segment having a tertiary segment length that is longer than the tertiary spatial major axis and shorter than the cutting path length, and at least some of the locations along the tertiary segment length being impinged multiple times by the tertiary laser pulses of the tertiary group of passes, the tertiary segment including a subsequent portion of the cutting path other than the primary or secondary segments, wherein:   the subsequent portion of the cutting path has a nonoverlap length greater than any one of the primary, secondary, and tertiary spatial major axes;   at least one of the primary, secondary, and tertiary groups of passes of respective primary, secondary, and tertiary laser pulses comprises multiple laser pulses of laser output that propagate along a beam axis, the laser output having a wavelength and the multiple laser pulses including first, second, and third consecutive laser pulses generated at a repetition rate;   a beam positioning system imparts relative motion of the wafer substrate and the beam axis;   the laser output is directed toward the surface of the target material such that the first, second, and third consecutive laser pulses impinge the surface with respective first, second, and third spot areas to contribute to formation of a trim line along the cutting path; and   control of the relative motion is coordinated with the repetition rate such that the second spot area partly overlaps the first spot area and impinges a first nonoverlapping area having a first nonoverlap spatial major axis of 0.5-9.5 μm and such that the third spot area partly overlaps the second spot area and impinges a second nonoverlapping area having a second nonoverlap spatial major axis of 0.5-9.5 μm, the laser output removing an amount of target material from the surface along the trim line and generating debris that primarily comprises nonmolten materials such that the generated debris that contacts the surface is nonpermanent and removable from the surface by a cleaning technique.   
     
     
       73. The method of claim 72 further comprising:
 cleaning the debris from the surface by mechanical scrubbing, solvent bathing, ultrasonic vibrating, ion milling, or reactive ion etching.   
     
     
       74. The method of claim 72 in which the laser pulses comprise a peak power density of greater than about 500 MW/cm 2  per pulse. 
     
     
       75. The method of claim 74 in which the repetition rate is greater than about 5 kHz. 
     
     
       76. The method of claim 75 in which the ceramic target material comprises AlTiC, the glass target material comprises silicon dioxide or vacuum-deposited alumina. 
     
     
       77. The method of claim 72 in which the target material resides along a length of a space between adjacent electronic devices, further comprising:
 applying a single pass or multiple passes of successive partly overlapping spot areas along the length of the space between the adjacent electronic devices to separate the adjacent electronic devices.   
     
     
       78. The method of claim 77, further comprising:
 applying a single pass of successive partly overlapping laser output pulses to edges formed between the adjacent electronic devices to convert the edges into rounded edges.   
     
     
       79. A method of laser processing a workpiece including a wafer containing multiple spaced-apart rows of multiple spaced-apart electronic devices, comprising:
 directing to the workpiece a primary group of passes of primary laser pulses to impinge locations along a primary segment of a cutting path that is continuous and has a cutting path length, each primary laser pulse having a primary spot area that defines a primary spatial major axis on the workpiece and impinging a location along the primary segment, the primary segment having a primary segment length that is longer than the primary spatial major axis and shorter than the cutting path length, and at least some of the locations along the primary segment length being impinged multiple times by the primary laser pulses of the primary group of passes;   directing to the workpiece a secondary group of passes of secondary laser pulses to impinge locations along a secondary segment of the cutting path, each secondary laser pulse having a secondary spot area that defines a secondary spatial major axis on the workpiece and impinging a location along the secondary segment, the secondary segment having a secondary segment length that is longer than the secondary spatial major axis and shorter than the cutting path length, and at least some of the locations along the secondary segment length being impinged multiple times by the secondary laser pulses of the secondary group of passes, the secondary segment overlapping the primary segment by an overlap length greater than at least the primary or secondary spatial major axes; and   after directing to the workpiece at least the primary and secondary groups of passes of respective primary and secondary laser pulses, directing to the workpiece a tertiary group of passes of tertiary laser pulses to impinge locations along a tertiary segment of the cutting path, each tertiary laser pulse having a tertiary spot area that defines a tertiary spatial major axis on the workpiece and impinging a location along the tertiary segment, the tertiary segment having a tertiary segment length that is longer than the tertiary spatial major axis and shorter than the cutting path length, and at least some of the locations along the tertiary segment length being impinged multiple times by the tertiary laser pulses of the tertiary group of passes, the tertiary segment including a subsequent portion of the cutting path other than the primary or secondary segments, wherein:   the subsequent portion of the cutting path has a nonoverlap length greater than any one of the primary, secondary, and tertiary spatial major axes;   beam positioning system components impart relative motion of the wafer and a beam axis;   at least one of the primary, secondary, and tertiary groups of passes of respective primary, secondary, and tertiary laser pulses comprises a first series of laser outputs that propagate along the beam axis, the laser outputs having a wavelength and including first, second, and third consecutive laser pulses generated at a first repetition rate;   the first series of laser outputs is directed toward a first surface in a first space between a first row of electronic devices and a second row of electronic devices such that the first, second, and third consecutive laser pulses impinge the first space with respective first, second, and third spot areas to contribute to formation of a first trim line along the cutting path;   control of the relative motion is coordinated with the first repetition rate such that the second spot area partly overlaps the first spot area and impinges a first nonoverlapping area having a first nonoverlap spatial major axis of 0.01-9.5 μm and such that the third spot area partly overlaps the second spot area and impinges a second nonoverlapping area having a second nonoverlap spatial major axis of 0.01-9.5 μm;   a second set of primary, secondary, and tertiary groups of passes is directed along a second cutting path and at least one of the second set of primary, secondary, and tertiary groups of passes comprises a second series of laser outputs that propagate along the beam axis, the laser outputs including first, second, and third consecutive laser pulses generated at a second repetition rate;   the second series of laser outputs is directed toward the first surface in a second space between the second row of electronic devices and a third row of electronic devices such that the first, second, and third consecutive laser pulses impinge the second space with respective first, second, and third spot areas to contribute to formation of a second trim line along the second cutting path; and   control of the relative motion is coordinated with the second repetition rate such that the second spot area partly overlaps the first spot area and impinges a first nonoverlapping area having a first nonoverlap spatial major axis of 0.01-9.5 μm and such that the third spot area partly overlaps the second spot area and impinges a second nonoverlapping area having a second nonoverlap spatial major axis of 0.01-9.5 μm, whereby the first and second series of laser outputs form the first and second trim lines to cause the second row of electronic devices to be disconnected from the first and third rows of electronic devices.   
     
     
       80. The method of claim 79 in which each of the first and second spot areas of the first and second series of laser outputs comprises a spatial major axis of about 5-15 μm, and in which the first and second series of laser outputs comprise a peak power density greater than about 500 MW/cm 2  per pulse. 
     
     
       81. The method of claim 79 in which the first and second surfaces are formed in proximity to each space and have pristine grain structure. 
     
     
       82. The method of claim 79 in which the surfaces comprise AlTiC or vacuum-deposited alumina. 
     
     
       83. The method of claim 79 in which the surfaces comprise silicon, silicon carbide, or titanium carbide. 
     
     
       84. A method of laser processing a workpiece including a row of multiple spaced-apart electronic devices;
 beam positioning system components impart relative motion of the row of multiple spaced-apart electronic devices and a beam axis, comprising:   directing to the workpiece a primary group of passes of primary laser pulses to impinge locations along a primary segment of a cutting path that is continuous and has a cutting path length, each primary laser pulse having a primary spot area that defines a primary spatial major axis on the workpiece and impinging a location along the primary segment, the primary segment having a primary segment length that is longer than the primary spatial major axis and shorter than the cutting path length, and at least some of the locations along the primary segment length being impinged multiple times by the primary laser pulses of the primary group of passes;   directing to the workpiece a secondary group of passes of secondary laser pulses to impinge locations along a secondary segment of the cutting path, each secondary laser pulse having a secondary spot area that defines a secondary spatial major axis on the workpiece and impinging a location along the secondary segment, the secondary segment having a secondary segment length that is longer than the secondary spatial major axis and shorter than the cutting path length, and at least some of the locations along the secondary segment length being impinged multiple times by the secondary laser pulses of the secondary group of passes, the secondary segment overlapping the primary segment by an overlap length greater than at least the primary or secondary spatial major axes; and   after directing to the workpiece at least the primary and secondary groups of passes of respective primary and secondary laser pulses, directing to the workpiece a tertiary group of passes of tertiary laser pulses to impinge locations along a tertiary segment of the cutting path, each tertiary laser pulse having a tertiary spot area that defines a tertiary spatial major axis on the workpiece and impinging a location along the tertiary segment, the tertiary segment having a tertiary segment length that is longer than the tertiary spatial major axis and shorter than the cutting path length, and at least some of the locations along the tertiary segment length being impinged multiple times by the tertiary laser pulses of the tertiary group of passes, the tertiary segment including a subsequent portion of the cutting path other than the primary or secondary segments, wherein:   the subsequent portion of the cutting path has a nonoverlap length greater than any one of the primary, secondary, and tertiary spatial major axes;   at least one of the primary, secondary, and tertiary groups of passes of respective primary, secondary, and tertiary laser pulses comprises a first series of laser outputs that propagate along the beam axis, the laser outputs having a wavelength and including first, second, and third consecutive laser pulses generated at a first repetition rate;   the first series of laser outputs is directed toward a first surface in a first space between a first electronic device and a second electronic device such that the first, second, and third consecutive laser pulses impinge the first space with respective first, second, and third spot areas to contribute to formation of a first trim line along the cutting path;   control of the relative motion is coordinated with the first repetition rate such that the second spot area partly overlaps the first spot area and impinges a first nonoverlapping area having a first nonoverlap spatial major axis of 1-7 μm and such that the third spot area partly overlaps the second spot area and impinges a second nonoverlapping area having a first nonoverlap spatial major axis of 1-7 μm;   a second set of primary, secondary, and tertiary groups of passes is directed along a second cutting path and at least one of the second set of primary, secondary, and tertiary groups of passes comprises a second series of laser outputs that propagate along the beam axis, the laser outputs including first, second, and third consecutive laser pulses generated at a second repetition rate;   the second series of laser outputs is directed toward the first surface in a second space between the second electronic device and a third electronic device such that the first, second, and third consecutive laser pulses impinge the first space with respective first, second, and third spot areas to contribute to formation of a second trim line along the second cutting path; and   control of the relative motion is coordinated with the second repetition rate such that the second spot area partly overlaps the first spot area and impinges a first nonoverlapping area having a first nonoverlap spatial major axis of 1-7 μm and such that the third spot area partly overlaps the second spot area and impinges a second nonoverlapping area having a second nonoverlap spatial major axis of 1-7 μm, whereby the first and second series of laser outputs form the first and second trim lines to cause the second electronic device to be disconnected from the first and third electronic devices.   
     
     
       85. The method of claim 84 in which the primary and secondary spatial major axes are about 5-15 μm, and in which the primary and secondary laser pulses comprise an energy density greater than about 500 MW/cm 2  per pulse. 
     
     
       86. The method of claim 84 in which the first and second surfaces are formed in proximity to each of the first and second spaces and have pristine grain structure. 
     
     
       87. The method of claim 84 in which the surfaces comprise AlTiC or vacuum-deposited alumina. 
     
     
       88. The method of claim 84 in which the surfaces comprise silicon, silicon carbide, or titanium carbide. 
     
     
       89. The method of claim 52 in which the device comprises a laser diode, optical waveguide, or MEMS component. 
     
     
       90. The method of claim 79 in which the laser outputs are generated by at least two lasers. 
     
     
       91. The method of claim 72 in which at least one of the multiple laser pulses has a wavelength of about 266 nm and a minimum energy per pulse of 150 microjoules. 
     
     
       92. The method of claim 52 in which the wavelength and the repetition rate constitute members of a set of laser processing window parameters, further comprising:
 selecting, as members of the set, additional laser processing window parameters that facilitate laser processing at the spatial major axes selected for the first and second nonoverlapping areas, the additional laser processing window parameters including pulse widths shorter than 80 ns for the laser pulses, spatial major axes of less than 300 μm for the first, second, and third spot areas, and pulse energies greater than 150 μJ per laser pulse so that cracking, degree of melt lip formation, or formation of permanent redeposition debris is minimized.   
     
     
       93. The method of claim 79 in which the wavelength and the first and second repetition rates constitute members of a set of laser processing window parameters, further comprising:
 selecting, as members of the set, additional laser processing window parameters that facilitate laser processing at the spatial major axes selected for the first and second nonoverlapping areas, the additional laser processing window parameters including pulse widths shorter than 80 ns for the laser pulses, spatial major axes of less than 300 μm for the first, second, and third spot areas, and pulse energies greater than 150 μJ per laser pulse so that cracking, degree of melt lip formation, or formation of permanent redeposition debris is minimized.   
     
     
       94. The method of claim 84 in which the wavelength and the first and second repetition rates constitute members of a set of laser processing window parameters, further comprising:
 selecting, as members of the set, additional laser processing window parameters that facilitate laser processing at the spatial major axes selected for the first and second nonoverlapping areas, the additional laser processing window parameters including pulse widths shorter than 80 ns for the laser pulses, spatial major axes of less than 300 μm for the first, second, and third spot areas, and pulse energies greater than 150 μJ per laser pulse so that cracking, degree of melt lip formation, or formation of permanent redeposition debris is minimized.   
     
     
       95. The method of claim 79, further comprising:
 selecting a segment length for any one or all of the primary, secondary, and tertiary segments and thereafter directing to the workpiece the primary, secondary, or tertiary group of passes.   
     
     
       96. The method of claim 79, in which primary, secondary, or tertiary laser pulses have a wavelength shorter than or equal to about 355 nm.