WO2006000549A1

WO2006000549A1 - Laser machining device for drilling holes into a workpiece comprising an optical deflecting device and a diverting unit

Info

Publication number: WO2006000549A1
Application number: PCT/EP2005/052866
Authority: WO
Inventors: Hans Jürgen Mayer; Uwe Metka
Original assignee: Hitachi Via Mechanics, Ltd.
Priority date: 2004-06-29
Filing date: 2005-06-21
Publication date: 2006-01-05
Also published as: WO2006000549A8

Abstract

The invention relates to a laser machining device (100) for drilling holes into a workpiece, particularly into an electronic circuit substrate (150), which comprises: a laser source (110) provided for emitting a laser beam (111); a diverting unit (130) for directing the laser beam (121) to a defined drilling position (154) on the circuit substrate (150), and; a projection lens (140) for focussing the laser beam (141) on the circuit substrate (150). The laser machining device also comprises an optical deflecting device (120), which is situated between the laser source and the diverting unit, serves to carry out the periodic two-dimensional diversion of a laser beam, and which has an optical element and a rotary actuator. The optical element is mounted in a manner that enables it to rotate about a rotation axis and has a planar boundary surface whose normal to the surface is oriented at an angle to the rotation axis and which is such that, when a laser beam impinges thereupon, it deflects this laser beam from its original direction. The rotary actuator is designed for continuously rotating the optical element about the rotation axis.

Description

LASER PROCESSING MACHINE FOR DRILLING HOLES IN A WORKPIECE WITH AN OPTICAL LIFTING DEVICE AND A DEFLECTION UNIT

description

The invention relates to a laser processing machine for drilling holes in a workpiece, in particular in electronic circuit substrates, wherein a laser beam generated by a Laserlicht¬ source via a deflection and a 10 imaging optics on the respective drilling position of the Workpiece is steered.

From US 5,593,606 a laser drilling method and a corresponding laser drilling apparatus is known, wherein holes having a diameter greater than the beam diameter of the laser beam are generated by the laser beam either in spiral tracks or in concentric circles within the hole area from the inside to the outside or from the outside is moved inside. When drilling electronic circuit carriers, according to the conventional methods, the positions of the drill holes are approached one after the other with the respectively used deflection unit. In this case, the laser beam is brought from an initial position, for example a preceding borehole, in a jumping motion onto the center of the hole to be drilled, then moved onto the circular path with the predetermined radius and finally once or on a predetermined circular path or spiral path Move several times until the desired 30 hole is created. This is followed by a jump movement back to the next hole position.

As deflecting units, two rotatably mounted mirrors are usually used, which are each pivotable about an axis by means of a so-called galvo drive. The two axes are usually arranged perpendicular to each other. Through a combination of pivotal movements of the two Mirror, the laser beam can be arbitrarily aligned within a zweidimensiona¬ len edit field. The use of conventional deflection units for traversing a circular movement has the disadvantage that as a result of the inertia of the mechanical system of mirror and galvo motor, the resulting path movement has significant deviations from the ideal circular path, depending on the speed and the radius of the circular motion. The consequence is that at high speed, in particular, the roundness of a drilled hole, which is regarded as the authoritative quality criteria of a borehole, can no longer be achieved to the extent required for the production of high-quality electronic circuit boards. Since the roundness of corresponding boreholes thus becomes worse, the faster the circular movement is carried out, a corresponding laser machining machine for drilling holes can only be operated with a limited machining speed, so that the drilling power, ie the maximum number of units per unit of time holes drilled to a certain hole quality is reduced. In practice, a compromise must always be found between high drilling performance and high hole quality.

The object of the present invention is to provide a laser processing machine for drilling holes in a workpiece, which on the one hand enables a high quality of drilled holes and on the other hand a high drilling performance.

The object is achieved by a laser processing device having the features of independent claim 1. The laser processing machine according to the invention for drilling holes in a workpiece, in particular in an electronic circuit substrate, comprises a laser source configured to emit a laser beam, a deflection unit for directing the laser beam to a particular drilling position (154) on the circuit substrate and imaging optics to Focusing the laser beam on the circuit substrate. The laser processing machine further comprises an optical Aus¬ steering device arranged between the laser source and the deflection unit for the periodic two-dimensional deflection of a laser beam having an optical element and a rotary drive. The optical element is rotatably mounted about a rotation axis and has a plane boundary surface whose surface normal is oriented at an angle to the axis of rotation and which is such that it deflects it from its original direction when the laser beam hits it. The rotary drive is set up for continuously rotating the optical element about the axis of rotation.

The invention is based on the finding that a circular movement within a working surface can be achieved not only by the combination of two pivoting movements of deflecting mirrors, but that a continuous rotational movement of an optical element can be generated, which is the direction of an input laser beam, for example by Reflection or by refraction in a Aus¬ gangslaserstrahl directs. Its variable beam path thus runs on a cone sheath, which is arranged symmetrically about a zero position. The invention has the advantage that only a simple rotational movement is required for beam deflection, so that, when an imbalance of the optical element is avoided, a significantly increased circular velocity of the deflected laser beam is possible in comparison to conventional deflection units.

The laser processing machine according to claim 2, wherein the imaging optics is an F-theta optic, ensures a direct relationship between the resulting deflection angle and the distance between a respective processing position and the so-called zero beam, which without the influence of inventive device or arrangement would hit the workpiece. The proportionality factor is given by the design of the F-theta optics, ie one in the F Theta optic entering beam with a defined Ein¬ case angle corresponds to a position on the Bearbeitungs¬ surface, which is spaced correspondingly from the zero position of the F-theta optics. For the proportionality factor between see deflection angle and deflection from the zero position results from a simple rule of three the following relationship:

K F

In this case, W _{πpt is} the angular range in which the laser beam strikes F-theta optics and which leads to a field length of F, ie to a maximum distance between the laser beams which impinge perpendicularly on the processing surface. W _a is the deflection angle of the Device or arrangement according to the invention, which upon rotation of the optical element leads to a circle radius K.

Thus, for example, at an optical angle range W _npt = ± 20 °, which leads to a deflection range of F = 50 mm, with a desired circle radius of 50 μm, a required deflection angle is achieved by the device or arrangement of 0.02 ° ,

The following relationship applies to the required rotational frequency of the optical element:

V is the speed at which the machining laser beam is moved on the circular path and B is the length of the circular path. For the above example of a circle radius K of 50 .mu.m, in which a circular path length of B = 2πK = 314 microns results, and a desired machining speed B on the circular path of 200 mm / s, there is a rotation frequency of 637 Hz This corresponds to 38217 revolutions per minute. Such high revolutions can at Avoidance of imbalance of the optical element can be realized with ordinary drive mechanism.

According to claim 3, the deflection of the input laser beam by refraction, which takes place as a result of the Brechungsgeset¬ zes of Snellius at least one of the two boundary surfaces of the optical element. The interface rotates in an angular position relative to the direction of the incident input laser beam. This transmission geometry has the advantage that a fast modulating of a circular path is possible on the incident laser beam without complicated beam paths.

According to claim 4, the input interface of the optical element is arranged perpendicular to the axis of rotation and the Dreh¬ axis is aligned parallel to the direction of incidence of the Eingangslaser¬ beam. This has the advantage that the deflection of the laser beam can be realized with a simple beam path in which no refraction takes place through the input interface of the optical element. The deflection angle thus depends only on the refractive index and the Keilwin¬ angle of the optical element. By using a rotary drive which engages from the outside to the wedge-shaped optical element, it is ensured that neither the beam path of the input laser beam nor the beam path of the output laser beam is disturbed by the rotary drive or other coupled with the rotary drive components.

According to claim 5, the interface is a mirror surface. Such a reflection geometry has the advantage that the modulating of the circular motion can be combined with a beam deflection, for example by 90 °, so that the specular interface serves both as an inventive optical element and as a reflector for beam deflection within a laser processing machine. Another advantage of the reflection geometry is that the rotary drive can be easily arranged behind the mirror surface, so that a disturbance of the beam path is excluded. The mirror surface can also be arranged on a wedge-shaped optical element, so that the opening angle of the conical surface on which the beam paths of the deflected laser beams are determined only by the corresponding wedge angle. The wedge angle is the angle which is defined by the mirror surface and a plane perpendicular to the axis of rotation.

According to claim 6, the laser processing machine on two optical deflection devices for the periodic zweidimensio¬ nal deflection of a laser beam. These are oriented relative to one another in such a way that when a laser beam deflected by the optical element of the deflection device impinges on it, it is again deflected by the further optical element of the further deflection devices. Thus, the deflection angle can be adjusted within a relatively wide range by a corresponding series connection of several optical deflection devices in a simple manner.

The arrangement according to claim 7 comprises a control device, by means of which the two rotary drives can be controlled in such a way that the optical element and the further optical element rotate at the same rotational speed and thus with a fixed phase position with respect to the rotational movement. The relative phase position between the two optical elements thus determines the effective deflection angle, so that the deflection angle and thus the radius of the resulting circular path of a deflected laser beam can be set in a simple manner by varying the relative phase position.

At this point, reference is made to a special case in which two identical optical elements are used with the same wedge angle and always a relative phase of the two rotational movements of 180 ° is maintained, ie that the beam deflection of the first optical element is just compensated by the beam deflection of the second optical element. In this case, the resulting beam deflection does not result in a deflection by a certain angle but in a parallel offset of the output laser beam in comparison to the input laser beam. Such a parallel offset is most easily achieved by the use of two wedge-shaped optical elements in transmission geometry, the input interface of the first optical element being perpendicular to the input laser beam and the output interface of the second optical element being perpendicular to the output laser beam. The parallel offset is then determined by the wedge angle and the distance between the two wedge-shaped optical elements, so that the parallel offset of the laser beam can be adjusted by varying the distance between the two optical elements in a simple manner. It should be noted that such a parallel offset can also be achieved with two optical elements in reflection geometry.

According to claim 8, the two rotary actuators can be controlled such that the optical element and the further optical element rotate at different rotational speeds. This causes a temporally variable phase position with respect to the rotational movement, so that at least when using two identical optical elements, the resulting beam deflection with different deflection angle in the range of 0, ie the second optical element just compensates the beam deflection by the first optical element , up to a maximum beam deflection can take place, in which the second optical element additionally increases the beam deflection caused by the first optical element. If the rotational movements of the two optical elements are not synchronized, laser processing takes place within a certain period of time within a planar circular area or at least to the zero position concentric region. When synchronizing the different Chen chen speeds, the deflected laser beam on the target object a defined waveform, for example, an outwardly or inwardly extending spiral path describe.

Further advantages and features of the present invention will become apparent from the following exemplary description of presently preferred embodiments.

1 shows a schematic representation of a laser processing machine according to the invention for drilling holes, FIG. 2 shows the beam deflection by a rotating wedge-shaped optical element in transmission geometry, FIG. 3 shows the beam deflection by a rotating wedge-shaped mirror element in reflection geometry, FIG. 4 shows the beam deflection 5 shows the beam deflection through an arrangement of two rotating wedge-shaped mirror elements in reflection geometry and FIG. 6 shows the beam deflection through an arrangement of a rotating wedge-shaped optical element in transmission geometry and a rotating wedge-shaped Mirror element in reflection geometry.

It should be noted at this point that in the drawing, the reference symbols of corresponding components differ only in their first digit.

The laser processing machine 100 shown in FIG. 1 comprises a laser source 110 which emits an input laser beam 111 which enters a deflection device 120. The deflection device 120 comprises a device or arrangement according to the invention for the periodic two-dimensional deflection of a laser beam, which is described below will be explained with reference to Figures 2 to 6. The Auslenkein¬ direction 120 generates an output laser beam 121 which has a beam path which is periodically moved about the axis of the so-called. Null beam, which extends on an extension of the input laser beam 111 on the lateral surface of a cone. The output laser beam 121 strikes a conventional deflection unit 130, which can be constructed in a conventional manner with galvo mirrors, and is subsequently directed onto the substrate 150 to be processed as processing laser beam 141 by way of imaging optics 140, for example an F-theta optic. In the example shown, the substrate 150 consists of a dielectric layer 151, which is covered by a metallic layer 152 on the upper side and underside, respectively. The metallic layers 152 are structured in a manner not shown to form interconnects. To produce electronic connections between the two metal layers 152, microholes 153 are drilled, the walls of which are subsequently metallized in a known manner. In order to generate the microholes 153, the processing laser beam 141 is centered in each case by means of a jump movement 155 on a drilling position 154 and then moved in a circular motion with a focus variable F set via the imaging optics 140 in the region of the drilling position 154 so that a microhole is generated in each case becomes. Depending on the given conditions (substrate material, hole depth, laser power, etc.), the processing laser beam 141 is thereby moved in one revolution or in several successive revolutions. For drilling holes with a diameter which is greater than the focal diameter, the so-called trephining is frequently used. In this case, the laser beam 141 is guided only along the edge of the hole and the inner core is cut out. In the production of microholes, it may also be necessary to perform several rotations of the laser beam 141 with different radii.

According to the invention, it is now provided that the conventional deflection unit 130 only has the jump movement 155 of the bearing. processing laser beam 141 with the respective setting to a drilling position 154, while the required circular motion is modulated by the deflection device 120, which is the deflection unit 130 upstream. The laser source 110 is preferably switched off during jump movement 155 and switched on again after reaching the new drilling position 154.

FIG. 2 shows a deflection device 220, by means of which an input laser beam 211 in transmission geometry as a result of refraction through a wedge-shaped optical element 260 is deflected by a deflection angle β into an output laser beam 221. The wedge-shaped optical element 260 is rotatable about an axis of rotation 261, so that the beam path of the output laser beam 221 moves on the lateral surface of a cone and describes a circular movement on a processing field, not shown, which is perpendicular to the axis of rotation 261. The wedge-shaped optical element has an input interface 262 which, according to the exemplary embodiment illustrated here, is arranged perpendicular to the beam path of the input laser beam 211. Since the axis of rotation 261 is aligned parallel to the input laser beam 211, the input interface 262 is perpendicular to the input laser beam 211 in each phase of rotation of the wedge-shaped optical element 260. Thus, no change in direction takes place when the input laser beam 211 enters the input interface 262. When the laser beam exits through the opposite output interface 263, which differs by a defined wedge angle a. is inclined to the entrance boundary surface 262, a change in direction of the laser beam due to Snell's law of refraction occurs, so that the output laser beam 221 is inclined by a deflection angle β with respect to the direction of the input laser beam 211. The change in direction is dependent on the wedge angle a and the refractive index of the optically transparent material from which the wedge-shaped optical element 260 is made. Upon rotation of the wedge-shaped optical element 260 about the axis of rotation 261, a circular movement is thus modulated onto the laser beam at the resulting angle β. The deflection device 220 can be combined with an F-theta optics, not shown, which deflects the output laser beam 221 into a machining position dependent on the deflection angle β on the machining surface of a workpiece not shown, the respective machining position being at a distance of the zero position of the laser beam, which depends on the design of the F-theta optics. For different circular diameters different wedge-shaped optical elements 260 are selected with different wedge angles α. The speed at which a circular path on the workpiece is traversed is determined by the radius of the circular path and by the rotational frequency xs of the optical element 260.

The deflection device 320 shown in FIG. 3 differs from the deflection device 220 in that the deflection device 320 is operated in reflection geometry. The optical element 360 is rotatable about a rotation axis 361 at a rotational speed ω by means of a rotary drive 361a. The wedge-shaped optical element 360 has a mirror surface 364, which is inclined by a wedge angle a relative to a plane oriented perpendicular to the axis of rotation 361. Upon rotation of the optical element 360, the input laser beam 311 is reflected at the mirror surface 364, the reflected output laser beam 321 being deflected by an angle β with respect to a null beam which would be generated by reflection at a mirror surface perpendicular to the rotation axis 361. The output laser beams 321 generated during a rotation of the optical element 360 thus likewise lie on a conical surface with an aperture angle 2/3 and describe a circular movement 322 on a processing surface (not shown) oriented perpendicular to the zero beam. FIG. 4 shows a deflection arrangement 420, in which two wedge-shaped optical elements, a first optical element 460 and a second optical element 465, both of which are operated in transmission geometry, are connected in series. The first wedge-shaped optical element 460 leads, as in FIG The first optical element 460 has an input interface 462 and an output interface 463 inclined by a wedge angle a _± with respect to the input interface 462. The input interface 462 is aligned perpendicular to the axis of rotation 461, which is arranged parallel to the incident Eingangsla¬ serstrahl 411. Upon rotation of the optical element 460 about the axis of rotation 461 with the rotational speed α> 1, the output laser beam 421 describes a circular movement 422.

The output laser beam 421 impinges as input laser beam 421 on the second wedge-shaped optical element, which has an input interface 467 and an output interface 468. The second wedge-shaped optical element 465 is likewise rotatable about a rotation axis 466 by means of a rotary drive, not shown, wherein the rotation axis 466 runs parallel to the rotation axis 461. The output interface 468 is oriented perpendicular to the axis of rotation 466, the input interface 467 is a wedge angle α? inclined to the output interface 468.

As can be seen from FIG. 4, the input laser beam 421 experiences a further deflection both at the input interface 467 and at the output interface 468 as a result of the optical refraction, so that the output laser beam 469 generated thereby is altogether deflected at an angle β with respect to the input laser beam 411. Upon rotation of the second wedge-shaped optical element 465 with a speed of rotation ee> ₂ , which equals the rotational speed β> i This results in a resulting circular motion 472 of the output laser beam on a correspondingly arranged processing surface (not shown).

With the same relative phase angle of the two rotational movements α> i and 00 ₂ , the two deflection effects of the two optical elements 460 and 465 add up. By setting the relative phase angle between two identically large rotational motions α> i and (H ₂ , the resulting In the special case, the use of two identical wedge-shaped optical elements, which are arranged opposite each other with their beveled surface and which are adjusted with respect to the phase position of their rotational movement such that the two inclined boundary surfaces always parallel The second wedge-shaped optical element 465 just compensates for the deflection through the first wedge-shaped optical element 460. However, this results in a parallel offset of the laser beam emerging from the output interface 468 compared to the input boundary che 462 entering laser beam.

With the same rotational speed coi and ω _{2 of} the two optical elements 460 and 465, the resulting deflection angle β can thus be adjusted precisely by selecting the relative phase position of both rotational movements such that the machining laser beam is circular on a workpiece, not shown departs with a fixed vorgege¬ circle diameter.

It should be noted that the two optical elements 460 and 465 can also be arranged rotated by 180 ° from the point of view of the incident input laser beam 411, ie that the laser beam 411 is initially an inclined interface and / or the output laser beam 421 is initially perpendicular penetrates to the axis of rotation 466 arranged interface. It is further pointed out that the two wedge-shaped optical elements 460 and 465 can also be operated with different rotational speeds »i and ω ₂ . In the case of an unsynchronized rotary movement, a material processing thus results within a processing range concentric about the zero beam in the course of a certain processing time. In the case of a predetermined time-varying phase position between the two rotary movements, instead of a circular movement, another curve shape can also be generated on the processing field which deviates from a circular path. As preferred examples of a curve shape deviating from a circular path, mention may be made here of a spiral shape described inwardly or outwardly.

FIG. 5 shows a deflection arrangement 520, by means of which an input laser beam 511 is reflected by a reflection at two wedge-shaped optical elements 560 and 565 into an output laser beam 569. The deflection arrangement 520 differs from the deflection arrangement 420 in that the beam deflection does not take place in transmission geometry but in reflection geometry. The principles of the two two-stage beam deflections are therefore identical except for the difference that the beam deflection by means of refraction takes place in the deflection arrangement 420 and the beam deflection by reflection takes place in the deflection arrangement 520. The first wedge-shaped optical element 560 is rotatable around a rotation axis 561 by means of a rotary drive (not shown). The first optical element 560 has a mirror surface 564, which is inclined by a wedge angle a.χ with respect to a base surface of the first optical element that is perpendicular to the axis of rotation 561. The input laser beam 511 is thus reflected at the mirror surface 564, so that the resulting output laser beam 521 experiences a deflection from a null beam, which would be generated in the case of reflection at a mirror surface perpendicular to the axis of rotation 561. Upon rotation of the first optical element with the rotational speed O ₁ describes the output laser beam 521 a circular motion on a cone sheath. The output laser beam 521, as the input laser beam 521, strikes the second wedge-shaped optical element 565 which has a mirror surface 564a which, with a plane perpendicular to the axis of rotation 566, has a wedge angle α? includes. The second wedge-shaped optical element 565 is rotated about the axis of rotation 566 at the speed of rotation <Ü ₂ . The reflection at the mirror surface 564a leads to a further beam deflection, so that the output laser beam 569 is deflected overall by an angle β with respect to the input laser beam 511.

With regard to the relationship between the two rotational speeds Oi and (ύ ₂ and the relative phase angle between the two rotational movements, the same explanations apply, which have already been explained above in connection with the deflection arrangement 420. It should be noted that the two wedge-shaped optical elements 560 and 565 may be arranged to each other such that the longitudinal axis of the cone shroud, which at the same rotational speed G _h = (O _{2 is described} by the time-varying beam path of the output laser beam 569, with a Paral¬ lelversatz parallel to the beam path of the Eingangslaser¬ This is precisely the case when the two axes of rotation 561 and 566 are oriented parallel to one another, which has the advantage that the resulting beam path is not provided at an angle but only with a parallel offset and thus an adjustment the Ausienkanordung 520 within e Iner laser processing machine erleich¬ tert.

FIG. 6 shows a deflection arrangement 620 in which an input laser beam 611 is deflected into an output laser beam 669 by means of a two-stage deflection process. The first stage of the beam deflection takes place by means of a first wedge-shaped optical element 660 in transmission geometry. The optical element 660, which has an input boundary surface 662 and an output boundary surface 663, which are opposite to one another. is tilted about the input interface 662 by a wedge angle αi is rotatable about a rotational axis 661 by means of a rotary drive, not shown, with a rotational speed ooi. As already described in connection with FIG. 2, a rotation of the first wedge-shaped optical element 660 generates a time-variable optical path of the output laser beam 621 lying on a conical surface.

The output laser beam 621 serves as an input laser beam 621 for the second wedge-shaped optical element 665 which is rotatable about an axis of rotation 666 by means of a rotary drive, not shown, and has a mirror surface 664a which is inclined relative to a surface perpendicular to the axis of rotation 666 by a wedge angle a _Σ is. At the same rotational speed e> i = ω _z , the output laser beam 669 on a workpiece (not shown) describes a circular movement 672, whose circle diameter depends on the resulting. Deflection angle ß and their circular velocity of the Dreh¬ speed CO ₁ = CO ₂ depends.

With regard to the relationship between the two rotational speeds β) i and G> ₂ and the relative phase position between the two rotational movements, the same principles apply, which have previously been described with reference to the articulation arrangement 420 illustrated in FIG.

Claims

claims

1. A laser processing machine for drilling holes in a workpiece, in particular in an electronic circuit substrate (150), comprising • a laser source (110) arranged to emit a laser beam (111), • an optical deflection device (120) for periodic two-dimensional deflection a laser beam comprising - an optical element (260, 360) and - a rotary drive (361a), - wherein the optical element (260, 360) is rotatably mounted about an axis of rotation (211, 311) and a plane boundary surface (263 , 364) whose surface normal is oriented at an angle to the axis of rotation (261, 361) and which is such that it deflects it from its origin when the laser beam (211, 311) strikes, and - wherein the rotary drive ( 361a) for continuously rotating the optical element (260, 360) about the rotation axis (261, 361), • a deflection unit (130) for directing the laser beam (121) to a specific one Drilling position (154) on the Schaltungs¬ substrate (150), wherein the deflection unit (130) has two rotatably mounted Galvo mirror, and • an imaging optics (140) for focusing the Laser¬ beam (141) on the circuit substrate (150).

2. A laser processing machine according to claim 1, wherein the imaging optics is an F-theta optic (140).

3. A laser processing machine according to any one of claims 1 to 2, wherein the optical element is a wedge-shaped element (260) which • is made of an optically transparent material and • an input interface (262) and an output interface (263).

4. Laser processing machine according to one of claims 1 to 3, wherein the grenzinangsgrenzflache (262) perpendicular to the axis of rotation (261) is arranged and the axis of rotation (261) is orientable in space so that it is aligned parallel to the laser beam (211) ,

5. A laser processing machine according to any one of claims 1 to 4, wherein the interface is a mirror surface (364).

6. Laser processing machine according to one of claims 1 to 5, in addition to • another optical deflection device for periodi¬'s two-dimensional deflection of a laser beam, wel¬ che - another optical element (465, 565) and - has a further rotary drive, - another optical element (465, 565) is rotatably mounted about a further axis of rotation (466, 566) and has a further plane boundary surface (467, 564a) whose surface normal is oriented at an angle to the further axis of rotation (466, 566) and such is arranged to deflect it out of its direction of origin when the laser beam (421, 521) strikes it, and - wherein the further rotary drive is arranged for continuously rotating the further optical element (465, 565) about the further axis of rotation (466, 566) , wherein the optical deflection device and the further optical deflection device are arranged relative to each other such that upon impact of a v on the optical element (460, 560) deflected laser beam (421, 521) through this the further optical element (465, 565) is deflected again.

7. Laser processing machine according to claim 6, additionally comprising a control device, by means of which the rotary drive (361a) and the further rotary drive can be controlled such that the two optical elements (460, 465, 560, 565) rotate at the same rotational speed.

8. Laser processing machine according to claim 6, additionally comprising a control device, by means of which the rotary drive (361a) and the further rotary drive can be controlled such that the two optical elements (460, 465, 560, 565) rotate at different rotational speed.