JP4297952B2 - Laser processing equipment - Google Patents

Description

  The present invention relates to a laser processing apparatus mainly for drilling a workpiece such as a printed circuit board, and more particularly to a simultaneous multi-point irradiation type laser processing apparatus for the purpose of improving productivity.

  Conventionally, in order to improve productivity, a laser processing apparatus has been proposed that can split one laser beam from a laser light source into two and simultaneously process two holes (see, for example, Patent Document 1). In this laser processing apparatus, one laser beam is split into two laser beams by the first polarizing unit, and again guided to the second polarizing unit that substantially matches the optical paths of these two laser beams. At this time, one laser beam (hereinafter referred to as a main beam) among the laser beams dispersed by the first polarization unit is guided to the second polarization unit via a pair of mirrors (bend mirrors). . The other laser beam (hereinafter referred to as a sub beam) is scanned in a biaxial direction that is not parallel to each other by the pair of first galvano scanner groups, and then guided to the second polarization means and mixed. The two laser beams that have passed through the second polarizing means are scanned in a biaxial direction that is not parallel to each other by the pair of second galvano scanner groups, enter the fθ lens, and irradiate the workpiece on the table. . Here, since the sub beam is scanned by the first galvano scanner group, there is a slight deviation in the angle compared to the main beam that has passed through one set of mirrors. The main beam and the sub beam are irradiated at different positions on the table. As a result, two holes can be processed simultaneously with one fθ lens, and productivity is improved.

  In addition to this, one laser beam is split into two laser beams by the first polarization means, and each laser beam is scanned in a biaxial direction by a pair of galvano scanners. There has also been proposed a laser processing apparatus in which two holes are simultaneously processed with one fθ lens after being guided to the polarizing means (see Patent Document 2, for example).

  In addition, a technique for generating an angle command value of each galvano scanner for processing a hole at a target position in a laser processing apparatus as seen in Patent Document 1 is also known (see, for example, Patent Document 3). .

International Publication No. 03/041904 Pamphlet Japanese Patent Laying-Open No. 2005-230872 International Publication No. 03/080283 Pamphlet

  By the way, in the laser processing apparatus described in Patent Document 1, there are a total of 2 sets (that is, 4 sets) on one side of the divided sub-beam, and more galvanometers than 1 set (2 sets) on the main beam side. It will go through the scanner. Since the galvano scanner is used by rotating the mirror part, it is unstable compared with the case where it passes through a fixed mirror, so the problem that the processing quality of the secondary beam that passes through such a galvano scanner tends to be deteriorated. There was a point.

  Further, in the sub beam, the beam is scanned by the first galvano scanner group installed at a position away from the front focal position of the fθ lens (the beam scanning ideal position before the fθ lens). Therefore, the longer the distance from the front focal position of the fθ lens to the first galvano scanner group, the worse the processing hole quality, such as the processing hole roundness and the focus tolerance, due to the characteristics of the fθ lens. As a result, there is a problem in that the quality of the processed hole for the workpiece is also deteriorated.

  In the laser processing apparatus described in Patent Document 2, the laser light split into two by the first polarizing means is configured to be scanned via a galvano scanner instead of a fixed mirror, and fθ Since a space for providing the second polarizing means is required between the lens and the galvano scanner, both laser beams are scanned at a position away from the front focal position of the fθ lens. As a result, both laser beams have a problem that the quality of the processed hole is deteriorated.

  Further, in the configuration like the laser processing apparatus described in Patent Document 1, since the optical system is complicated, calibration such as angle command values of each galvano scanner required for controlling the beam position described in Patent Document 3 is required. In the work, there is also a problem that a lot of points are required for trial processing and it takes time.

  The present invention has been made in view of the above, and obtains a laser processing apparatus capable of reducing the difference in processing quality between two laser beams and improving the processing quality in a simultaneous multipoint irradiation type laser processing apparatus. For the purpose. It is another object of the present invention to provide a laser processing apparatus that can facilitate a calibration operation necessary for controlling a processing position to be irradiated with laser light.

  In order to achieve the above object, a laser processing apparatus according to the present invention is a laser processing apparatus that performs processing by simultaneously irradiating two or more points on a work piece arranged on a table with laser light. Are arranged on the optical path of the first laser light, and the first laser light in the first direction on the table is split into the first and second laser lights having different optical paths. A first galvano scanner that scans the second laser beam and a second laser beam that is disposed on the optical path of the second laser beam and scans the second laser beam in a second direction different from the first direction on the table Two galvano scanners, second polarization means for mixing the first and second laser beams, and third and fourth different first and second laser beams mixed on the table. A pair of third and fourth gears scanning in the direction A main galvanometer scanner formed of Banosukyana, characterized in that it comprises, a fθ lens for respectively condensing the first and second laser beam at a predetermined position on the workpiece from the main galvano scanner.

  According to the present invention, since any laser beam dispersed by the first polarizing means is configured to pass through three galvano scanners, the processing quality can be improved while maintaining the productivity of simultaneous multi-point irradiation. It has the effect of being able to.

  Exemplary embodiments of a laser processing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments.

Embodiment 1 FIG.
Before describing the laser processing apparatus according to the present invention, an outline of the configuration of a conventional laser processing apparatus will be described. FIG. 14 is a diagram showing a conventional example of the structure of a simultaneous multipoint irradiation type laser processing apparatus. The laser processing apparatus places a workpiece 212 such as a printed circuit board, and moves an XY table 211 that can move in a horizontal plane (XY plane) and laser light L emitted from a laser oscillator (not shown) on the XY table 211. An optical system for irradiating the workpiece 212. In this figure, the surface of the XY table 211 on which the workpiece 212 is placed is a horizontal plane, and two axes orthogonal to each other in the horizontal plane are an X axis and a Y axis, and both the X axis and the Y axis are used. The axis perpendicular to is the Z axis.

  The optical system is spectrally divided by a first polarizing unit 222 including a polarizing beam splitter that splits a laser beam L emitted from a laser oscillator (not shown) into two laser beams La and Lb, and a first polarizing unit 222, Two laser beams La and Lb traveling in different optical paths are mixed (mixed) and mixed from the second polarizing means 223 composed of a polarizing beam splitter or the like that guides it to the substantially same optical path. And an fθ lens 228 for condensing the laser beams La and Lb on the workpiece 212. The two laser beams La and Lb split between the first polarizing unit 222 and the second polarizing unit 223 are configured to have the same optical path length. Further, the reason why the two laser beams La and Lb are mixed by the second polarizing means 223 is that two holes are simultaneously processed using one fθ lens 228.

  For simplicity, the mirrors 221a to 221a are arranged on the optical paths of the laser beams L, La, and Lb so that the optical paths of the laser beams L, La, and Lb are substantially parallel to any of the X axis, Y axis, and Z axis set above. The case where 221d and the galvano scanners 224a, 224b, 226a, 226b are arranged will be described. In this case, the mirrors 221a to 221d arranged on the optical path bend (reflect) the optical path of the laser light L at an angle of 90 degrees, for example, with respect to any axis of the XYZ coordinate system shown in the figure. , Arranged at an angle of 45 degrees. A pair of galvano scanners 224a and 224b for scanning the laser light Lb in two axial directions and guiding it to the second polarizing means 223 are provided on the optical path of the laser light Lb reflected by the first polarizing means 222. Provided. The galvano scanner 224a is arranged so that the rotation axis of the mirror 225a is in the X-axis direction, and the galvano scanner 224b is arranged so that the rotation axis of the mirror 225b is in the Y-axis direction. By scanning the galvano scanner 224a, the laser beam Lb can be scanned in the X-axis direction on the XY table 211, and by scanning the galvano scanner 224b, the laser beam Lb can be scanned in the Y-axis direction on the XY table 211. Can be scanned.

  Further, between the second polarizing means 223 and the fθ lens 228, a pair for scanning the mixed laser beams La and Lb from the second polarizing means 223 in the biaxial direction and guiding them to the workpiece 212. Galvano scanners 226a and 226b are provided. The galvano scanner 226a is arranged so that the rotation axis of the mirror 227a is in the Z-axis direction, and the galvano scanner 226b is arranged so that the rotation axis of the mirror 227b is in the X-axis direction. By scanning the galvano scanner 226a, the laser beams La and Lb can be scanned in the X-axis direction on the XY table 211, and by scanning the galvano scanner 226b, the laser beams La and Lb are scanned on the XY table 211. Scanning in the Y-axis direction is possible.

  Here, the operation of the laser processing apparatus having such a configuration will be described. A laser beam L emitted from a laser oscillator (not shown) is adjusted to have a polarization direction of 45 degrees, is reflected by two mirrors 221a and 221b, and enters the first polarization unit 222. In the first polarizing means 222, the light is split into laser light whose polarization direction is P wave perpendicular to the incident surface and laser light whose polarization direction is S wave parallel to the incident surface.

  Laser light (hereinafter referred to as a main beam) La transmitted through the first polarizing means 222 is guided to the second polarizing means 223 via the two mirrors 221c and 221d. On the other hand, laser light (hereinafter referred to as a secondary beam) Lb reflected by the first polarizing means 222 is guided to the second polarizing means 223 after being scanned in the biaxial direction by the galvano scanners 224a and 224b. Here, the main beam La is always guided to the second polarization unit 223 at the same position, but the sub beam Lb is incident on the second polarization unit 223 by controlling the swing angle of the galvano scanners 224a and 224b. The position and angle to be adjusted are adjusted.

  Thereafter, the main beam La is reflected by the second polarizing means 223, and the sub-beam Lb is transmitted by the second polarizing means 223, so that the two laser beams La and Lb follow the galvano scanner 226a, 226b. Then, after being scanned in the biaxial direction by the galvano scanners 226a and 226b, the galvano scanners 226a and 226b are guided to the fθ lens 228 and focused on predetermined positions on the workpiece 212 to perform processing. At this time, by scanning the galvano scanners 224a, 224b, 226a, and 226b, it is possible to irradiate two different points on the workpiece 212 with the main beam La and the sub beam Lb. After all the holes in the scanning area are processed, the next scanning area can be processed by moving the XY table 211 in the XY direction in the drawing.

  Here, when each of the first set of galvano scanners 224a and 224b is set to a certain angle, the split laser beam Lb draws the same locus after the second polarizing means 223, and the same position is processed. Assuming that there are two sufficiently close hole positions a and b to be processed, first, the second set of galvano scanners 226a and 226b are arranged in two axial directions so that one of the hole positions (for example, a) is processed. If scanning is performed, the main beam La forms a hole at the position a. Next, if the first set of galvano scanners 226a and 226b scan further in the biaxial direction from the hole position A to the other hole position B, the sub beam Lb processes the other hole position B.

  As described above, in the laser processing apparatus having the configuration shown in FIG. 14, the second set of galvano scanners 226a and 226b perform main scanning, and the first set of galvano scanners 224a and 224b move from the above-described hole position a to the hole position. It can be thought of as a role of differential scanning as in (b), and it was easy to understand the mechanism intuitively. In addition, the deflection angle scanned by the first set of galvano scanners 224a and 224b is actually smaller than the deflection angle scanned by the second set of galvano scanners 226a and 226b.

  However, in such a laser processing apparatus, one of the split sub-beams Lb passes through a total of two sets (that is, four) and many galvano scanners 224a, 224b, 226a, 226b. Since the galvano scanner is used by rotating the mirror part, it is unstable compared to the case of passing through the fixed mirror, and the processing by the secondary beam Lb is inevitably processed quality (the processing quality here is the hole in the scan area). There is a problem that the quality of the drilled hole such as roundness and focus tolerance and the variation of the machining position accuracy are likely to deteriorate. In addition, the long distance from the front focal position of the fθ lens 228 to the farthest galvano scanner 224a that performs beam scanning is one of the causes of poor processing quality (particularly processing hole quality).

  Therefore, in the present invention, the processing quality of the two laser beams is worse than the processing quality of the main beam in the conventional laser processing apparatus, but the processing quality of the sub beam can be improved. A laser processing apparatus is provided. Below, the laser processing apparatus concerning this invention is demonstrated.

  FIG. 1 is a diagram showing a configuration of a first embodiment of a laser processing apparatus according to the present invention, and FIG. 2 shows an arrangement relationship of galvano scanners near a front focal position of an fθ lens of the laser processing apparatus of FIG. FIG. In this laser processing apparatus, a workpiece 12 such as a printed circuit board is placed, an XY table 11 that can move in a horizontal plane (XY plane), a laser oscillator 20 that emits laser light L, and a laser oscillator 20 that emits light. An optical system for irradiating the workpiece 12 on the XY table 11 with the laser beam L, and an imaging means such as a CCD (Charge-Coupled Device) camera for imaging the processing position on the XY table 11 during trial processing 29, and a laser oscillator 20 and a control unit 30 for controlling a mirror angle of galvano scanners 23a, 23b, 26a, and 26b, which will be described later, constituting the optical system and the image pickup means 29. In this figure, the surface of the XY table 11 on which the workpiece 12 is placed is a horizontal plane, two axes orthogonal to each other in the horizontal plane are an X axis and a Y axis, and both the X axis and the Y axis are included. The axis perpendicular to is the Z axis.

  The optical system includes a first polarization unit 21 including a polarization beam splitter that splits the laser beam L emitted from the laser oscillator 20, and a plurality of mirrors 22a that reflect the split laser beams Lα and Lβ and guide them to the optical path. To 22f and galvano scanners 23a and 23b that scan the laser beams Lα and Lβ of the respective optical paths in different directions on the XY table 11 (hereinafter, these galvano scanners 23a and 23b are also referred to as sub-galvano scanners 23a and 23b). ) And the second polarizing means 25 composed of a polarizing beam splitter or the like that mixes two laser beams Lα and Lβ that have been split by the first polarizing means 21 and traveled in different optical paths, and guides them to substantially the same optical path, A galvanoscan that scans the mixed laser beams Lα and Lβ from the second polarizing means 25 on the XY table 11 in different directions. Na 26a, 26b (hereinafter, these galvano scanners 26a, 26b are also referred to as main galvano scanner 26), fθ lens 28 for condensing the mixed laser beams Lα, Lβ on the workpiece 12, Is provided. Here, the sub galvano scanners 23a and 23b correspond to the first and second galvano scanners in the claims, and the main galvano scanners 26a and 26b similarly correspond to the third and fourth galvano scanners.

  For simplicity, the mirrors 22a to 22f and the galvano scanners 23a, 23b, 26a, and 26b arranged on the optical path have almost the same optical path of the laser light L, Lα, and Lβ as any of the X axis, Y axis, and Z axis. For the purpose of bending (reflecting) the laser beams L, Lα, and Lβ at an angle of 90 degrees so as to be parallel, for example, an angle of 45 degrees is formed with respect to any axis of the XYZ coordinate system shown in the figure. Will be described. The laser light Lα on the side transmitted by the first polarizing means 21 is reflected by the second polarizing means 25, and the laser light Lβ on the side reflected by the first polarizing means 21 is transmitted by the second polarizing means 25. Thus, the optical path is configured. The optical path lengths of the laser beams Lα and Lβ dispersed between the first polarizing unit 21 and the second polarizing unit 25 are configured to be the same.

  In the first embodiment, both the number of mirrors 22a to 22f and the number of galvano scanners 23a and 23b arranged on the optical path of the two laser beams Lα and Lβ dispersed by the first polarizing means 21 are two. It arrange | positions so that it may become equal in an optical path. Also, a galvano scanner arrangement method has been devised so that there is no difference in characteristics between the two laser beams Lα and Lβ. That is, the optical path lengths from the fθ lens to the arrangement positions of the galvano scanners 23a and 23b are both designed to be equal in the two optical paths.

  That is, n (n is a natural number) mirrors (22a to 22c) on the optical path to the second polarizing means 25 of the laser light (hereinafter referred to as α beam) Lα transmitted through the first polarizing means 21. One galvano scanner 23a is provided. Further, n mirrors (22d to 22f) and one galvano scanner 23b are disposed on the optical path to the second polarizing means 25 of the laser light (hereinafter referred to as β beam) Lβ reflected by the first polarizing means 21. Is provided. However, in the case of FIG. 1, n = 3. With this configuration, the same number of mirrors and galvanometer mirrors are arranged on the two optical paths, so that the quality of the laser light passing through the two optical paths is the same.

  In the first embodiment, as shown in FIGS. 1 and 2, for example, the main galvano scanner 26a is arranged so that the rotation axis of the mirror 27a is in the Z-axis direction, and the main galvano scanner 26b is It can be considered that the rotation axis 27b is arranged in the X-axis direction.

  The mirrors 27a and 27b of the galvano scanners 26a and 26b that scan the laser are preferably at the front focal position F of the fθ lens 28. However, in practice, it is impossible to place a plurality of mirrors at the same position, so consider as close to this situation as possible. That is, the mirror 27a of the galvano scanner 26a and the mirror 27b of the galvano scanner 26b are located as close to the front focal position F of the fθ lens 28 as possible, and the center position of the mirror 27a of the galvano scanner 26a and the center position of the mirror 27b of the galvano scanner 26b. The main galvano scanners 26 a and 26 b are arranged so that the midpoint of the line connecting the two points is the front focal position F of the fθ lens 28. However, at this time, considering that the mirrors 27a and 27b of the main galvano scanners 26a and 26b rotate, the two mirrors 27a and 27b (galvano scanners 26a and 26b are arranged so as not to interfere with each other). ) Distance 2Y must be selected.

  In the example shown in FIG. 2, considering the case where the rotation of the mirror 27a of the galvano scanner 26a is fixed and the galvano scanner 26b is rotated, the incident positions of the laser beams Lα and Lβ on the fθ lens 28 are in the Y-axis direction. Change along. Conversely, when the rotation of the mirror 27b of the galvano scanner 26b is fixed and the galvano scanner 26a is rotated, the incident positions of the laser beams Lα and Lβ on the fθ lens 28 change along the X-axis direction. In this way, the incident positions (incident angles) of the laser beams Lα and Lβ to the fθ lens 28 can be changed by scanning the galvano scanners 26a and 26b.

  Further, as shown in FIG. 1, the optical system is determined so that the scanning directions of the galvano scanner 23a for the α beam Lα and the galvano scanner 23b for the β beam Lβ are not the same. In the example of FIG. 1 (assuming an ideal fθ lens), the scanning direction of the galvano scanner 23a for the α beam Lα is the X direction immediately thereafter, and the X direction on the XY table 11 is the mirror direction. The galvano scanner 23a is arranged so that the rotational axis of 24a is in the Z-axis direction. Also, the scanning direction of the galvano scanner 23b for the β beam Lβ is the Z direction immediately thereafter and the Y direction on the XY table 11, so that the rotation axis of the mirror 24b is in the Y axis direction. Is placed. That is, the laser beam Lα can be scanned in the X-axis direction on the XY table 11 by scanning the galvano scanner 23a, and the laser beam Lβ can be scanned on the Y-axis on the XY table 11 by scanning the galvano scanner 23b. Can be scanned in the direction.

  The control unit 30 performs a calibration operation for obtaining the relationship between the mirror angle of the main galvano scanners 26a and 26b and the sub galvano scanners 23a and 23b and the position of the machining hole, and irradiates the positions of the machining holes with the laser beams Lα and Lβ. Therefore, the mirror angle of the main galvano scanner 26 and the sub galvano scanners 23a and 23b is controlled. The calibration work and the machining control work by the control unit 30 will be described in the fourth embodiment.

  Next, the operation of the laser processing apparatus having such a configuration will be described. The laser beam L oscillated from the laser oscillator 20 is split by the first polarizing means 21 into a transmission side laser beam Lα and a reflection side laser beam Lβ. The laser beam (that is, the α beam) Lα on the transmission side is guided to the second polarization means 25 via several fixed mirrors 22a to 22c and one galvano scanner 23a for the α beam. Similarly, the reflection-side laser beam (that is, β beam) Lβ is also guided to the second polarizing means 25 via several other fixed mirrors 22d to 22f and one β beam galvano scanner 23b. It is burned. The laser beams Lα and Lβ that have passed through the second polarizing means 25 are scanned by the main galvano scanners 26 a and 26 b and pass through the fθ lens 28, so that two points on the workpiece 12 are irradiated. Then, the workpiece 12 is processed. At this time, the mirror angles of the auxiliary galvano scanners 23 a and 23 b and the main galvano scanners 26 a and 26 b are both controlled based on the processing information set in advance by the control unit 30.

  Here, the reason why the processing quality can be improved by the laser processing apparatus according to the first embodiment will be described. The quality of the two laser beams Lα and Lβ dispersed between the first polarizing means 21 and the second polarizing means 25 is equalized by passing through the same number of mirrors and galvanometer mirrors. As a result, two points of variation in machining point position accuracy and machining hole quality are improved.

  The variation in machining point position accuracy is a variation in position at the machining point, and is an error variation with respect to the ideal position. The main cause of the variation in the processing point position accuracy is due to the angle variation at the time of galvano scanner scanning. The smaller the number of galvano scanners through which one laser beam passes, the better. According to the first embodiment, the α beam Lα and the β beam Lβ each pass through three galvano scanners and are fewer than the four beams through which the sub beam Lb in the conventional example passes. Is improved.

  On the other hand, the quality of the processed hole represents the degree of roundness of the processed hole when the galvano scanner is scanned in the scanning region while changing the Z-axis height. Normally, if the roundness ratio of the hole is equal to or greater than a predetermined value, it will be judged that the hole quality is good. The larger the Z-axis range where this hole quality is judged good, the wider the focus margin. This means that the hole quality is good. Here, the Z-axis includes the auxiliary galvano scanners 23 a and 23 b, the second polarizing means 25, the main galvano scanners 26 a and 26 b, and the fθ lens 28, and the upper surface of the XY table 11. It is a component group having a mechanism that moves in a direction parallel to a direction perpendicular to the direction (Z-axis direction).

  Generally, as the number of mirrors inserted into the optical path to the processing point increases, the quality (roundness) of the propagated laser light tends to deteriorate and the beam quality at the processing point tends to deteriorate. As a result, the hole quality is also deteriorated. This is because the mirror plane is strictly vertical and horizontal, and the irregularities are often different, and the laser beam propagating through such a mirror has a beam divergence angle and the Z position of the condensing point vertical and horizontal. This is because it will be greatly different. In particular, the mirrors of galvano scanners are specially shaped mirrors, and some of them have relatively poor flatness. Therefore, when multiple galvano scanners exist on the optical path, beam quality deteriorates at the processing point. Will become very large.

  FIG. 3A is a diagram schematically illustrating a state where the processing hole quality is good, and FIG. 3-2 is a diagram schematically illustrating a state where the processing hole quality is poor. As shown in FIG. 3A, when the number of mirrors and galvanometer mirrors through which the laser beam L propagates is small, the laser beam L is cut at the XZ plane and the YZ plane with reference to the coordinate axes shown in the figure. Since the shapes coincide with each other, the focal heights are the same, the beam is always a perfect circle, and the laser beam L is round no matter where it is cut on the Z axis near the focal position. However, as shown in FIG. 3-2, when the number of mirrors and galvanometer mirrors through which the laser beam L propagates is large, the laser beam L is cut along the XZ plane and the YZ plane with reference to the coordinate axes shown in the figure. The shapes of do not match. That is, the focal height (Z axis) is different. As a result, when the laser beam L is cut in a direction perpendicular to the Z axis near the focal position, an elliptical shape is obtained. FIG. 3-2 shows a case where the laser beam L changes from a horizontal ellipse to a vertical ellipse because the beam spread and the condensing position are different in the vertical and horizontal directions.

  FIG. 4 is a diagram illustrating an example of a method for evaluating the hole quality. The method for evaluating the hole quality is evaluated by obtaining a Z-axis range in which the roundness of the shape of the hole when the Z-axis height is changed is a predetermined percentage or more. That is, this Z-axis range is a range in which the quality of the processed hole is considered good. Also, the wider the Z-axis range, the easier it is to process.

  FIG. 5A is a diagram illustrating an example of a range in which the quality of the processing holes of the main beam and the sub beam in the conventional laser processing apparatus of FIG. 14 is determined to be good, and FIG. It is a figure which shows an example of the range in which it is judged that the processing hole quality of (alpha) beam and (beta) beam is good in the laser processing apparatus. First, as shown in FIG. 5-1, the number of galvano scanners 226a and 226b through which laser light propagates is small at two in the main beam La, but the galvano scanner 224a through which laser light propagates in the sub beam Lb. The number of 224b, 226a, 226b is as large as four. Therefore, the processing hole quality of the main beam La that propagates only the two galvano scanners 226a and 226b is high, but the processing hole quality of the sub beam Lb that propagates the four galvano scanners 224a, 224b, 226a, and 226b is extremely low. It has become. On the other hand, as shown in FIG. 5B, the α beam Lα and the β beam Lβ in which the number of galvano scanners through which the laser light propagates are three are the conventional lasers shown in FIG. The processing hole quality is better than the processing hole quality of the sub beam Lb of the processing apparatus. And the range where it is judged that the processing hole quality of the two laser beams is good is almost the same, the range where both overlap, that is, the Z-axis range where the quality of the processing hole processed by the two laser beams is good, It is wider than the case of the conventional laser processing apparatus of FIG. That is, by improving the beam quality of one laser beam having poor beam quality, it is possible to improve the processing hole quality of the entire laser processing apparatus. Further, the quality of the processed hole is improved as the arrangement distance from the front focal position F of the fθ lens 28 of the sub-galvano scanners 23a and 23b shown in FIG. 1 is shorter. That is, as shown in FIG. 1, according to the configuration of the first embodiment, one auxiliary galvano scanner 23a, 23b is arranged in each optical path through which the α beam Lα and the β beam Lβ propagate, and the arrangement Since the position can be brought close to the front focal position F, the hole quality can be improved. In addition, since the installation distances of the sub-galvano scanners 23a and 23b from the front focal position F are equal, the processing hole quality by the two laser beams Lα and Lβ is equivalent.

  According to the first embodiment, any of the split laser beams Lα and Lβ passes through only three galvano scanners, and the farthest sub-galvano scanners 23 a and 23 b that perform beam scanning from the front focal position F of the fθ lens 28. By shortening the distance, the problem that the processing quality of the conventional sub beam deteriorates while maintaining the same productivity as the conventional simultaneous multi-point irradiation type laser processing apparatus can be solved. In addition, since the processing quality of the two laser beams Lα and Lβ is equal, the range of the Z-axis height at which processing with good processing quality can be performed can be expanded, which is wider than conventional laser processing apparatuses. There is an effect that processing can be performed within a range of conditions.

Embodiment 2. FIG.
FIG. 6 is a diagram showing the configuration of the laser processing apparatus according to the second embodiment of the present invention, and FIG. 7-1 is a view from the X-axis direction of the auxiliary galvano scanner and the main galvano scanner of the laser processing apparatus of FIG. FIG. 7B is a diagram illustrating the positional relationship of the galvano scanner in the vicinity of the front focal position of the fθ lens of the laser processing apparatus of FIG. 6. This laser processing apparatus is characterized in that, in FIG. 1 of the first embodiment, the rotation axis of the mirror 27a of the galvano scanner 26a is disposed so as to be inclined by an angle θ with respect to the Z axis. Accordingly, the auxiliary galvano scanners 23a and 23b are also arranged so as to be inclined by an angle θ with respect to the positions in the first embodiment. The rotation axes of the mirrors 24a, 24b, and 27a of these galvano scanners 23a, 23b, and 26a constitute the same orthogonal coordinate system. Further, the XYZ coordinate system shown in the figure is arranged between the mirror 22b and the sub galvano scanner 23a in the two optical paths of the first embodiment and between the mirror 22d and the sub galvano scanner 23b. Two mirrors 22g to 22j for changing to an orthogonal coordinate system tilted by an angle [theta] as compared to 2 are arranged in each optical path. The optical path closer to the laser oscillator 20 than the mirrors 22g and 22i is configured to be parallel to any of the X, Y, and Z axes of the XYZ orthogonal coordinates provided with the XY table 11 as a reference. This is because it is necessary to be perpendicular to the XY plane in order to adjust the processing point height.

  The second embodiment is characterized in that the galvano scanner 26a is arranged in an inclined state on the lower side of the galvano scanner 26b. Specifically, as shown in FIGS. 7-1 to 7-2, the galvano scanner 26a is Y-axis within the YZ plane by an angle θ as compared with the arrangement position of the first embodiment shown in FIG. It is tilted in the positive direction. By tilting in this way, the distance between the two mirrors 27a and 27b can be narrowed compared to the case of the first embodiment, considering the distance at which the mirrors 27a and 27b do not interfere with each other. . As a result, the distance Y between the front focal position of the fθ lens 28 (the ideal beam scanning position before the fθ lens 28) and the two mirrors 27a and 27b is also shortened compared to the case of FIG. It is possible to improve the processing hole quality of the laser beam. In addition, as the galvano scanner 26a is tilted by the angle θ, the galvano scanners 23a and 23b are Z-axis positive in the YZ plane by an angle θ compared to the arrangement position of the first embodiment shown in FIG. It is tilted in the direction.

  When the galvano scanners 23a, 23b, and 26a are inclined as described above, the scanning directions of the laser beams Lα and Lβ on the XY table 11 when the galvano scanners 23a, 23b, 26a, and 26b are scanned are X The direction is parallel to the axis and the Y axis.

  According to the second embodiment, in addition to the effects of the first embodiment, the main galvano scanners 26a and 26b are arranged close to the front focal position F of the fθ lens 28. As a result, the hole quality can be further improved.

Embodiment 3 FIG.
In the second embodiment, in order to prevent the beam position from being changed by the operation by the Z-axis vertical adjustment mechanism (the structure that adjusts the focal position by operating the machining head portion), the light parallel to the Z-axis in the middle of the optical path. There is a problem that it is necessary to provide an axis, and the number of mirrors after the first beam split (first polarizing means 21) is two or more for one optical path than in the first embodiment. Therefore, in the third embodiment, a case will be described in which the number of mirrors after the first spectroscopy is the same as that in the first embodiment.

  FIG. 8 is a diagram showing the configuration of the third embodiment of the laser processing apparatus according to the present invention. This laser processing apparatus is characterized in that, in FIG. 1 of the first embodiment, only the galvano scanner 26a is arranged in an inclined state below the galvano scanner 26b. The arrangement position of the galvano scanner 26a is the same as that shown in FIG.

  Further, in the third embodiment, only the galvano scanner 26a is disposed so as to be inclined by an angle θ, and the other sub-galvano scanners 23a and 23b and the mirrors 22g to 22j have an optical path as in the first embodiment. The XY table 11 is arranged so as to be parallel to any of the X, Y, and Z axes of the XYZ coordinate system with the XY table 11 as a reference. Accordingly, it is possible to prevent the beam position from being changed by the operation of the Z axis vertical adjustment mechanism.

  In the case of the third embodiment, the scanning directions of the laser beams Lα and Lβ on the XY table 11 when the galvano scanners 23a, 23b, 26a, and 26 are scanned are the directions parallel to the X axis and the Y axis. The direction is parallel to two axes that intersect at a predetermined angle that is not a right angle.

  According to the third embodiment, the scanning coordinate system of the main galvano scanners 26a and 26b after the second polarizing means 25 is an orthogonal coordinate system based on the XY table 11, but the sub-polarization galvano scanners 23a and 23b Although the scanning coordinate system is not orthogonal and has a certain angle θ, the number of mirrors after the first beam split (first polarizing means 21) is the same as in the first embodiment, and the configuration can be reduced. Compared to mode 2, it has the effect that the deterioration of the hole quality can be suppressed.

Embodiment 4 FIG.
In the first to third embodiments, the arrangement of the galvano scanner and the mirror in the laser processing apparatus has been described. As described above, for example, in the optical system of the first embodiment, as shown in FIG. 1, when the scanning directions of the galvano scanner 23a for the α beam Lα and the galvano scanner 23b for the β beam Lβ are orthogonal to each other, This is easy to understand and can maximize the scanning area. For example, in the first embodiment (FIG. 1), assuming an ideal fθ lens 28, the scanning direction of the galvano scanner 23a for the α beam Lα is immediately in the X-axis direction. Since the scanning direction of the galvano scanner 23b for the β beam Lβ is the Z direction immediately after that, it is the Y axis direction on the XY table 11. However, in practice, the scanning direction by one galvano scanner does not become a straight line on the XY table 11 due to the difficulty of manufacturing the ideal fθ lens 28 and the limit of the lens mounting accuracy. Further, since the position of the machining hole can be controlled by the scanning method (control method) of the galvano scanner, as shown in the second and third embodiments, the galvano scanner 23a for the α beam Lα and the galvano for the β beam Lβ. It is also possible to adopt a configuration in which the scanning direction of the scanner 23b is not orthogonal. Therefore, in any case, the angles of the galvano scanners 23a, 23b, 26a, and 26b must be determined so that the target hole coordinates can be drilled. Therefore, in the fourth embodiment, a control method of the galvano scanner for performing hole machining on the target hole coordinates will be described.

  The laser processing apparatus is controlled by the control unit 30 as shown in FIGS. 1, 6, and 8. The control unit 30 includes a calibration function 31 that obtains the relationship between the mirror angle of the galvano scanners 23 a, 23 b, 26 a, and 26 b and the position of the machining hole formed on the XY table 11, and the target obtained by the calibration function 31. A model storage function 32 for storing a model for obtaining a mirror angle of the galvano scanners 23a, 23b, 26a, and 26b for performing a hole machining at a position to be processed, and a machining position such as a position for making a machining hole for the workpiece 12 Processing information storage function 33 for storing information and processing information stored in processing information storage function 33 for controlling galvano scanners 23a, 23b, 26a, 26b and laser oscillator 20 using a model of model storage function 32 And a control function 34.

  Below, the outline | summary of the control method in a laser processing apparatus is demonstrated first, and the calibration method for performing control next is demonstrated.

  In the laser processing apparatus, for the hole coordinates (target hole coordinates) on the XY table 11 to be processed, the angles (angle command values) of the galvano scanners 23a, 23b, 26a, and 26b that are to be processed are realized. The required function is required.

FIG. 9 is a block diagram showing the relationship between the mirror angle of each galvano scanner and the coordinates of the hole to be processed in the conventional simultaneous multipoint irradiation type laser processing apparatus shown in FIG. As shown in FIG. 9, in the conventional simultaneous multipoint irradiation type laser processing apparatus, the coordinates (a _x , a _y ) of the processing hole of the main beam La are obtained, and the coordinates (b _x of the processing hole of the sub beam Lb are obtained. , B _y ) is obtained by a difference from the coordinates (a _x , a _y ) of the machining hole of the main beam La. That is, main beam La of the machined hole coordinates (a _x, a _y), and the second pair in the optical scanner 226a, determined by the mirror angle 226b. The coordinates (b _x , b _y ) of the machining hole of one of the sub beams Lb depend on the mirror angle of the first galvano scanner 224a, 224b in addition to the mirror angle of the second galvano scanner 226a, 226b. Determine. However, when these main beam La and sub beam Lb are put together, if the mirror angles of the four galvano scanners 224a, 224b, 226a, and 226b are determined, the coordinates (four coordinate components) of the two processing holes are determined. There is a relationship of 4 inputs and 4 outputs. Thereby, these relationships can be understood as mapping relationships (for details, refer to Patent Document 2).

  By the way, in the laser processing apparatus according to the present invention, as described above, the two laser beams dispersed by the first polarizing means 21 are both propagated through the same number of galvano scanners, so that there is no dominance due to the beam quality. Therefore, there is no classification of main beam and sub beam and they are equivalent. That is, for the laser processing apparatus according to the present invention, a method for obtaining the mirror angles of the four galvano scanners for determining the coordinates of the two processing holes using the mapping relationship as shown in FIG. Therefore, a control method for newly determining the processing hole coordinates is required.

FIG. 10 is a block diagram showing the relationship between the mirror angle of each galvano scanner and the coordinates of the hole to be processed in the laser processing apparatus according to the present invention. As shown in FIG. 10, in the laser processing apparatus according to the present invention, when the α beam Lα is arranged on the optical path of the α beam Lα in addition to the mirror angle of the main galvano scanners 26a and 26b, the sub galvano scanner 23a The position coordinates (α _x , α _y ) of the processing hole are determined by the mirror angle. Also in the β beam Lβ, the position coordinates (β _x , β _y ) of the processing hole are determined by the mirror angle of the sub galvano scanner 23b arranged on the optical path of the β beam Lβ in addition to the mirror angle of the main galvano scanners 26a, 26b. Is decided. In summary, when the mirror angles of the four galvano scanners 23a, 23b, 26a, and 26b are determined, four processing hole coordinates α _x , α _y , β _x , and β _y (two holes respectively It can be seen that since there are X and Y coordinates, there is a mapping relationship that four variables) are determined.

Thus, in the fourth embodiment, the inverse mapping model of the mapping represented by the block diagram of FIG. 10 is used in order to obtain the coordinates of the two processing holes (components of the four processing hole coordinates). And Further, from FIG. 10, for the four inputs of the target position coordinates α _x , α _y , β _x , β _y of two machining holes, machining with the hole coordinates α _x , α _y , β _x , β _y is realized. Preferably, the four galvano scanners 23a, 23b, 26a, and 26b have four inputs and four outputs that output four variables of estimated angles g _a ^e , g _b ^e , g _c ^e , and g _d ^e. And The inverse mapping model used in the fourth embodiment uses a polynomial model including a 4-input 4-output polynomial, and uses four galvano scanners 23a, 23b, 26a, and 26b from the mirror angles of four machining holes. A function for obtaining the coordinates α _x , α _y , β _x , β _y is realized. Here, the polynomial means a mathematical expression that is calculated only by four arithmetic operations of constants and variables, and there are various kinds of types.

The inverse mapping model used in the fourth embodiment is expressed by the following equation (1) using a mathematical expression using a determinant. Here, B ^e is four galvanometer scanner 23a, 23b, 26a, is a matrix representing the estimated value of the mirror angle 26b, A is n order (n is a natural number) the target hole coordinates expressed by a polynomial model X is a coefficient matrix of the matrix A (or an unknown parameter matrix).

^Be = AX (1)

  For example, in the case of a first-order polynomial model, the following equation (2) having five terms is obtained, and in the case of a second-order polynomial model, the following equation (15) having 15 terms. In the case of a third-order polynomial model, the shape is as in the following equation (4) in which the number of terms is 35. It should be noted that a polynomial model other than the polynomial shown here can be considered, for example, using a part of equation (4).

In the above equation, the components k _1-1 , k _1-2 ,... Of the coefficient matrix X are polynomial coefficients, and are determined by a calibration method described later according to the characteristics of the optical system. As shown in these equations (2) to (4), the matrix X is a matrix composed of only polynomial coefficients. For example, in the case of a first-order polynomial model, the coefficient matrix X is a 5 × 4 matrix, and in the case of a second-order polynomial model, the coefficient matrix X is a 15 × 4 matrix, and a third-order polynomial In the case of the model, the coefficient matrix is a 35 × 4 matrix.

  If the order of the polynomial is increased and the number of terms is increased, the position of the machined hole can be controlled with higher accuracy. However, more data is required to obtain the coefficient matrix of the polynomial model. Any order polynomial can be used, but in the case of a laser processing apparatus for drilling a printed circuit board or the like as a result of experiments, a polynomial model consisting of all terms of order 3 or less (number of terms = 35) It was found that an inverse mapping model with the accuracy that satisfies the required specifications can be created using.

In order to obtain the coefficient (unknown parameter) of the above polynomial model, calibration processing is required. This calibration process is realized by the calibration function 31 of the control unit 30. In the calibration process, trial processing is performed by changing the mirror angle of each galvano scanner 23a, 23b, 26a, 26b to several values, and the actually processed hole coordinates are measured by the imaging means 29 such as a CCD camera. From the angle data g _a , g _b , g _c , g _{d of} each galvano scanner 23a, 23b, 26a, 26b and the hole coordinate data α _x , α _y , β _x , β _y processed at that time, a minimum of two The coefficient (unknown parameter) of the polynomial model is determined using a method such as multiplication or weighted least squares. The inverse mapping model (polynomial model) of the mapping of the two hole coordinates processed from the mirror angle of each galvano scanner calculated by the calibration function 31 as described above is stored in the model storage function 32.

  Also in this calibration process, the laser processing apparatus according to the present invention exhibits a remarkable effect that the working time can be shortened as compared with the conventional simultaneous multi-point irradiation type laser processing apparatus. This is shown by comparison in the following simple example.

  In the present invention and the conventional calibration process, the first set of galvano scanners 23a, 23b (or 224a, 224b) has four mirror angles, respectively, and the second set of galvano scanners 26a, 26b (or 226a, 226b). Compare the case where trial machining is performed with each of three mirror angles. FIG. 11 is a diagram showing a processing hole position when a conventional simultaneous multi-point irradiation type laser processing apparatus is used, and FIG. 12 shows a processing hole position when the laser processing apparatus according to the present invention is used. For simplicity, it is assumed that the fθ lenses 28 and 228 are ideally scanned here on the XY tables 11 and 211 on a straight line. In these drawings, the horizontal axis indicates the X axis on the XY tables 11, 211, and the vertical axis indicates the Y axis on the XY tables 11, 211. In addition, “◯” indicates the position of the processing hole formed by the main beam La or α beam Lα, and “X” indicates the position of the processing hole formed by the sub beam Lb or β beam Lβ. Yes.

  FIG. 13 is a diagram showing the number of processed holes necessary for calibration. When trial processing is performed with a conventional laser processing apparatus (FIG. 14), there are 3 × 3 × 4 × 4 = 144 combinations of mirror angles of the galvano scanner, but since there are two laser beams La and Lb, it is confirmed. There are 288 ways. However, due to the characteristics of the optical system, there is an overlapping portion processed at the same position. For example, as can be seen from the block diagram of FIG. 9, in the simultaneous multi-point irradiation type laser processing apparatus according to the prior art, the optical system of the main beam La does not depend on the mirror positions of the galvano scanners 224a and 224b. There may be 3 × 3 = 9. That is, since it is not necessary to process the case where the positions are the same, the number of holes that need to be confirmed is smaller than 288 patterns, and is 153 patterns.

  On the other hand, when trial processing is performed with the laser processing apparatus according to the present invention, there are 3 × 3 × 4 = 36 combinations of mirror angles of the galvano scanner, and two laser beams Lα and Lβ, so that 72 are confirmed. It becomes.

  Even in this simple example, in the case of the laser processing apparatus according to the present invention, the number of holes for trial processing at the time of calibration can be reduced by 81 as compared with the prior art. In actual calibration processing, the angle of the mirror of the galvano scanner needs to be more finely tuned, so the difference in the number of holes from the prior art becomes significant. In the calibration process, the coordinates of the trial-processed hole are measured by the image pickup means 29. The larger the number of holes, the longer the measurement work takes.

The coefficient matrix is obtained by the calibration process as described above, and the coefficients of the polynomial model are determined. In actual machining, the machining control function 34 of the control unit 30 sets the coordinates (α _x , α _y ), (β _x , β _y ) on the XY table 11 as positions where holes on the workpiece 12 are to be drilled. ) Is obtained from the machining information storage function 33, the position coordinates where the desired holes are to be drilled are input to the polynomial model stored in the model storage function 32, and the mirror angles g _a and g of the galvano scanner obtained as a result of calculation are obtained. The mirror angles of the galvano scanners 23a, 23b, 26a, and 26b are controlled so as to be _b , g _c , and g _d . As described above, it is possible to make a hole at a target position on the workpiece 12.

  In the above description, the case of the laser processing apparatus of the first embodiment has been described as an example. However, in the case of the second and third embodiments, the galvano scanners 23a, 23b, 26a, By controlling the mirror position of 26b, the position of the machining hole can be controlled.

  According to the fourth embodiment, since the same number of galvano scanners are arranged on the two optical paths split by the first polarizing means 21, the number of processing holes required for the calibration process can be reduced. It has a remarkable effect that the calibration processing time can be greatly shortened. For a laser processing apparatus having such an optical system, the position of the processing hole is controlled by an inverse mapping model of mapping to two hole coordinates processed from the mirror angle of four galvano scanners. Has the effect of being able to.

  In the first to fourth embodiments described above, an example is shown in which three galvano scanners are arranged on each optical path of laser light split into two, but the same number may be used for each optical path. For example, an arbitrary number of galvano scanners may be arranged. In addition, by applying this idea, a method of splitting two laser beams split into two, or a plurality of laser oscillators may be prepared to increase the number of simultaneously processed holes.

  As described above, the laser processing apparatus according to the present invention is useful when simultaneously performing a plurality of holes with high accuracy.

It is a figure which shows the structure of Embodiment 1 of the laser processing apparatus by this invention. It is a figure which shows the arrangement | positioning relationship of the galvano scanner near the front focal position of the f (theta) lens of the laser processing apparatus of FIG. It is a figure which shows typically a state with process hole quality good. It is a figure which shows typically the state where process hole quality is bad. It is a figure which shows an example of the evaluation method of processed hole quality. It is a figure which shows an example of the range judged that the processing hole quality of the main beam and sub beam in the conventional laser processing apparatus is good. It is a figure which shows an example of the range judged that the processing hole quality of (alpha) beam and (beta) beam is good in the laser processing apparatus of this Embodiment 1. FIG. It is a figure which shows the structure of Embodiment 2 of the laser processing apparatus by this invention. It is a figure which shows the arrangement | positioning relationship when it sees from the X-axis direction of the sub galvano scanner of the laser processing apparatus of FIG. 6, and a main galvano scanner. It is a figure which shows the arrangement | positioning relationship of the galvano scanner near the front focal position of the f (theta) lens of the laser processing apparatus of FIG. It is a figure which shows the structure of Embodiment 3 of the laser processing apparatus by this invention. It is a block diagram which shows the relationship between the mirror angle of each galvano scanner and the coordinate of the hole processed in the conventional simultaneous multipoint irradiation type laser processing apparatus. It is a block diagram which shows the relationship between the mirror angle of each galvano scanner and the coordinate of the hole processed in the laser processing apparatus by this invention. It is a figure which shows the processing hole position at the time of using the conventional simultaneous multipoint irradiation type laser processing apparatus. It is a figure which shows the processing hole position at the time of using the laser processing apparatus by this invention. It is a figure which shows the number of process holes required for calibration. It is a figure which shows the prior art example of the structure of the simultaneous multipoint irradiation type laser processing apparatus.

Explanation of symbols

11 XY Table 12 Workpiece 20 Laser Oscillator 21 First Polarizing Means 22a-22j, 24a, 24b, 27a, 27b Mirrors 23a, 23b, 26, 26a, 26b Galvano Scanner 25 Second Polarizing Means 28 fθ Lens 29 Imaging Means 30 Control unit 31 Calibration function 32 Model storage function 33 Processing information storage function 34 Processing control function

Claims (10)

In a laser processing apparatus that performs processing by simultaneously irradiating two or more points on a workpiece arranged on a table with laser light,
First polarization means for splitting one laser beam into first and second laser beams having different optical paths;
A first galvano scanner disposed on the optical path of the first laser light and scanning the first laser light in a first direction on the table;
A second galvano scanner disposed on the optical path of the second laser light and scanning the second laser light in a second direction different from the first direction on the table;
Second polarizing means for mixing the first and second laser beams;
A main galvano scanner comprising a pair of third and fourth galvano scanners that scan the mixed first and second laser beams in different third and fourth directions on the table;
An fθ lens that focuses the first and second laser beams from the main galvano scanner at predetermined positions on the workpiece;
A laser processing apparatus comprising:   The first and second galvano scanners are arranged at positions where the optical path lengths from the front focal position of the fθ lens are equal on the respective optical paths through which the first and second laser beams propagate. The laser processing apparatus according to claim 1, wherein the apparatus is a laser processing apparatus. When the direction orthogonal to both the first and second directions is the fifth direction,
The first to fourth galvano scanners are arranged such that the direction of the rotation axis of the mirror of the first to fourth galvano scanners is the same as any one of the first, second, and fifth directions. The laser processing apparatus according to claim 1, wherein the laser processing apparatus is provided. When the direction orthogonal to both the first and second directions is the fifth direction,
In the first, second, and fourth galvano scanners, the direction of the rotation axis of the mirror of the first, second, and fourth galvano scanners is the same as one of the first, second, and fifth directions. Arranged in a direction,
The third galvano scanner is disposed closer to the second polarizing means than the fourth galvano scanner, and the direction of the rotation axis of the mirror of the third galvano scanner is the first, second, fifth. The laser processing apparatus according to claim 1, wherein the laser processing apparatus is disposed so as to be inclined at a predetermined angle with respect to any one of the directions.   The number of galvano scanners arranged in the two optical paths between the first and second polarizing means is the same as the number of mirrors that guide the first and second laser beams in a predetermined direction. The laser processing apparatus according to claim 1, wherein the apparatus is a laser processing apparatus.   Calculation showing the relationship between the mirror angle of the first to fourth galvano scanners and the coordinates of the holes processed by the first and second laser beams irradiated on the table at the mirror angle. Based on the model, the mirror angles of the first to fourth galvano scanners are calculated corresponding to the target processing positions on the workpiece, and the mirror angles of the first to fourth galvano scanners are controlled. The laser processing apparatus according to claim 1, further comprising a control unit.   The calculation model is an inverse mapping model of mapping from a mirror angle of the first to fourth galvano scanners to irradiation coordinates on the table of the first and second laser beams. 6. The laser processing apparatus according to 6.   The inverse mapping model is represented by a polynomial model including a four-input four-output polynomial having four components constituting the irradiation coordinates as inputs and outputting the mirror angles of the first to fourth galvano scanners. The laser processing apparatus according to claim 7.   The laser processing apparatus according to claim 8, wherein the polynomial model is represented by a polynomial including a third-order term of four components of the irradiation coordinates.   The control means measures four components of irradiation coordinates on the table of the first and second laser beams when the mirror angles of the first to fourth galvano scanners are arbitrarily swung, 10. The apparatus according to claim 6, further comprising a function of calculating a calculation model indicating a relationship between a mirror angle of the first to fourth galvano scanners and four components of the irradiation coordinates. The laser processing apparatus as described in one.

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