CN110944789A

CN110944789A - Method for laser machining of a workpiece for material removal

Info

Publication number: CN110944789A
Application number: CN201880033716.8A
Authority: CN
Inventors: 托马斯·拉库尔
Original assignee: Automotive Lighting Reutlingen GmbH
Current assignee: Marelli Automotive Lighting Reutlingen Germany GmbH
Priority date: 2017-05-23
Filing date: 2018-05-17
Publication date: 2020-03-31
Also published as: DE102017111211B4; DE102017111211A1; WO2018215292A1

Abstract

The invention relates to a method for laser machining for material removal of a workpiece (10) comprising a carrier element (14) made of a synthetic material and having a surface (16) and a metallization layer (18) applied to the surface (16) in a preparatory phase of the laser machining, wherein the metallization layer (18) can be removed from the workpiece (10) having a three-dimensional extension in a large-area region of the surface (16).

Description

Method for laser machining of a workpiece for material removal

Technical Field

The invention relates to a method for laser machining for material removal of a workpiece, which comprises a carrier element made of a synthetic material and having a surface and a metallization layer applied to the surface in a preparatory phase of the laser machining. The laser machining is carried out by means of a laser machining device which comprises a laser unit and a control unit for actuating the laser unit. The method comprises the following steps:

-arranging the workpiece in a machining position in a working area of the laser unit;

-generating values for operating parameters for operating the laser unit;

-generating and emitting a laser beam by a laser unit in dependence on the generated values for the operating parameters;

the workpiece arranged in the machining position is loaded with the emitted laser beam in a machining point in the region of the surface of the workpiece provided with the metallization layer, so that the material of the metallization layer is locally removed in the machining point;

moving the laser beam and thus also the machining point along the working trajectory relative to the workpiece by means of the laser unit in the region of the surface of the workpiece provided with the metallization layer, in accordance with the values generated for the operating parameters, so as to remove material of the metallization layer along the working trajectory.

Furthermore, the invention relates to a laser processing apparatus according to the preamble of claim 11 and to a computer program according to the preamble of claim 16.

Background

The synthetic material of the carrier element may be transparent. Furthermore, it should be laser-resistant (no reflection). Laser machining, in which material is removed from a workpiece, is also referred to as laser ablation or laser evaporation. Here, material is removed from the surface by irradiating the surface coated with material with pulsed laser radiation. The laser radiation used in this case has a high power density and leads to rapid heating of the material and the formation of a plasma on the surface. In the case of laser pulses in the nanosecond range, the energy of the laser causes the surface to heat up (in the sense of thermal movement of atoms) during the laser pulse. Since thermal conduction enables only a slow energy transfer into the volume, the injected energy is concentrated on a very thin layer (about 1 μm at a pulse length of 10 ns), so that the material irradiated with the laser reaches very high temperatures and sudden evaporation of the material occurs. By ionization (thermally, by laser light or electron impact), a plasma of electrons and ions from the removed material is generated at the high power density of the laser.

Within the scope of the invention, the workpiece from which material should be removed comprises a carrier element made of a synthetic material having a surface and a metallization layer applied to the surface in a preparatory phase to laser machining. The synthetic material of the carrier element is preferably transparent.

The workpiece is, for example, a decorative element or a decorative cover for a motor vehicle lighting device. The interior of the headlight is lined, for example, with such a decorative cover (for example, around the projection lens of the PES module or around the reflector rim of the reflector module) in order to shield the rear, usually unsightly mechanical and electrical devices of the headlight from the outside by means of a transparent cover plate. For various reasons, for example for design reasons, it may be desirable to establish the transparency of the carrier element again at least in selected regions. It is thus conceivable, for example, to arrange a motor vehicle lamp behind the transparent section of the decorative cover, which then emits light through the transparent section of the decorative cover to perform the illumination function. It is also conceivable simply to position a light source behind the decorative cover, which illuminates the region behind the decorative cover, so that the transparent section of the decorative cover illuminates in order to achieve a special night design of the lighting device.

US 5,817,243 has already disclosed a method for removing material on different types of workpieces (for example metal, plastic or leather) and thereby introducing designs or patterns of as high a contrast as possible into the surface of the synthetic material piece. If the workpiece is a coated workpiece and a part of the coating is removed in the region of the laser removal, this is described only in connection with a coated metal part. If the workpiece is a transparent workpiece (for example a cover plate of a motorcycle headlight), it is merely described that a pattern can be introduced into the transparent material of the workpiece by means of a laser. Furthermore, it is described at different points that the method should produce a particularly detailed, fine pattern on the workpiece. This method is therefore not suitable for removing the material of the metallization layer from the larger surface of the piece of transparent synthetic material provided with the metallization layer. Furthermore, the method is not suitable for synthetic material parts having complex three-dimensional shapes.

Disclosure of Invention

The object of the present invention is therefore to design and improve a method of the type mentioned at the outset in such a way that even in the case of complex three-dimensional composite material pieces large-area material of the metallization layer can be removed.

To solve this object, the invention proposes a method having the features of claim 1. In particular, it is proposed that the machining point, in which the laser beam falls onto the surface to be machined of the synthetic material piece, be moved back and forth along a plurality of parallel working paths, wherein adjacent working paths are arranged so closely next to one another that the machining point of the laser beam on one working path adjoins or partially overlaps the machining point of the laser beam on the adjacent working path in order to remove large-area material of the metallization layer. Furthermore, the laser unit is moved as a function of the generated values for the operating parameters in order to change the position of the machining point and to follow the three-dimensional course of the surface provided with the metallization layer when the working path is traversed.

The machining point of the laser beam moves along a plurality of side-by-side meandering paths, so that the material of the metallization layer can be removed over a large area in the desired region on the workpiece surface. Preferably, the angle at which the laser beam impinges on the workpiece surface remains constant during the travel of the machining point of the laser beam over the meandering working path. In the case of a three-dimensional profile viewed in the global coordinate system of the surface, the beam direction therefore needs to be adapted constantly in the global coordinate system. The change in the direction of the laser beam can be achieved either by the laser unit having suitable deflection means (for example adjustable deflection mirrors) so that the emission direction of the laser beam from the laser unit can be changed. However, it is also conceivable to change the position and orientation of the entire laser unit, the emission direction of the laser beam from the laser unit remaining constant. The position and orientation of the laser unit follows the three-dimensional course of the surface provided with the metallization layer, whereby the laser beam always strikes the surface at a constant angle.

It is conceivable here for either the entire laser unit or only a part of the laser unit to be moved. In particular, it is conceivable not to move the part of the laser unit that comprises the laser medium and the resonator. The movement of the laser unit or a part thereof comprises inter alia a linear movement in X, Y and/or Z-direction. Furthermore, moving the laser unit or a part thereof may also comprise rotating around one or more of said X-axis, Y-axis and/or Z-axis.

Preferably, the entire laser unit is moved in position and orientation and in this case follows a complex three-dimensional course of the workpiece surface. The movement of the laser unit is carried out in accordance with values generated for operating parameters for operating the laser unit. Thus, the operating parameters include, for example, the position (X, Y, Z), orientation, and adjustment speed of the laser unit. Furthermore, the operating parameters can include, in particular, the pulse duration, the pulse frequency and the power of the laser beam or of the laser unit. In particular, it is conceivable that the pulse duration, the pulse frequency and the power of the laser unit are set to constant values during the actual laser machining. In this case, the power, pulse duration and pulse frequency must be adjusted as precisely as possible, so that the metallization layer is removed as completely as possible in the desired layer thickness without damaging the carrier layer. In particular, the light transmission properties of the carrier layer should not be affected by the incident laser beam. The method according to the invention thus enables a large-area and precise material removal by the laser unit following the three-dimensional course of the surface of the workpiece provided with the metallization layer when traversing a meandering working path.

The laser unit is preferably moved during the travel of the side-by-side working paths in such a way that the angle of incidence of the laser beam onto the surface remains constant. In this way, the power density of the laser in the machining point can be kept at an approximately constant level.

In an advantageous development of the invention, the machining point of the laser beam is moved on the surface of the plastic part provided with the metallization layer by means of an actuator. The actuator may be configured to move the laser unit or only a portion of the laser unit. Preferably, the entire laser unit generating the laser beam is moved by means of an actuator. However, it may prove advantageous if, in order to change the position of the machining point, only a part of the laser unit is moved by the actuator. The laser unit comprises, for example, suitable deflection means (for example adjustable deflection mirrors) which are moved by means of an actuator so that the emission direction of the laser beam from the laser unit can be changed. The actuator is, for example, an electromagnetic actuator, which is designed to move the laser unit or a part of the laser unit in the direction X, Y, Z and/or to rotate it about one of the axes (X, Y, Z).

Advantageously, the actuator for moving the laser unit or a part thereof is controlled by the control unit. In particular, the control is performed as a function of the values generated for the operating parameters for operating the laser unit. In particular, the control is performed according to the values generated for the position (X, Y, Z), the orientation and the control speed.

In the sense of the present invention, the generation of the values for the operating parameters includes not only the generation of the values directly before or during the laser machining, but also a simple reading-in of the previously stored values. Advantageously, the values for the operating parameters of the laser unit are generated exclusively directly before or during the laser machining. It is conceivable that the values for the operating parameters are generated automatically by the control unit, for example on the basis of sensor signals which provide information about the exact three-dimensional course of the surface.

In a further advantageous embodiment of the invention, the values for the operating parameters of the laser unit are generated directly before or during the actual laser machining by loading into the control unit the values for the operating parameters for the particular application case in question, which were previously generated and stored before the laser machining.

Advantageously, the values for the operating parameters are generated from data of the workpiece (e.g. the material of the carrier element and the metallization layer, the thickness of the carrier element and the metallization layer). The data of the workpiece is for example manually entered by the user. Alternatively or in addition to this, however, it is also conceivable for the data of the workpiece to be transmitted to the control unit in the form of electronically stored values. In particular, data for various workpieces are stored, and the data for the workpiece to be machined are selected and loaded into the control unit, so that the laser unit is operated in this manner as a function of the data of the workpiece.

Advantageously, the values for the operating parameters are generated as a function of information about the three-dimensional shape of the workpiece and/or about the machining position of the workpiece and/or about the region of the metallization layer to be removed and/or about the material and/or the thickness of the metallization layer and/or about the material of the carrier element. The laser unit is operated in accordance with the workpiece to be machined, based on non-exhaustive information about the workpiece.

In an advantageous development of the method, it has proven to be advantageous to detect the machining position, in particular the position and/or the orientation of the workpiece, by means of the sensor element and to generate a value for the operating parameter as a function of the detected position and/or orientation. Preferably, the laser unit is operated in this way as a function of the position and/or orientation of the workpiece detected by the sensor element. In particular, it is possible to detect whether the workpiece is located in the processing position by means of the sensor element and to actuate the laser unit to emit the laser beam in the case of a workpiece located in the processing position. In addition, the sensor element can be used, for example, to detect the distance of the workpiece from the laser unit and to adapt the power of the laser unit to the detected distance from the workpiece. The sensor element comprises, for example, an optical sensor, in particular a camera or a light barrier, or a tactile sensor, a touch sensor. The touch sensor, for example, can be arranged at the machining position and detect the position and orientation of the workpiece.

Advantageously, the laser unit is operated according to a computer program that can be implemented on the control unit. The computer program is programmed such that when the computer program is executed on the control unit, the control unit implements or controls the method according to the invention. In this way, at least the actual laser machining of the workpiece can be automated within the scope of the method according to the invention. Furthermore, it is conceivable that the generation of the operating parameters takes place automatically within the scope of the execution of the computer program.

As a further solution to this object, a laser machining device for laser machining of a workpiece with material removal is proposed, the workpiece comprising a carrier element made of a synthetic material and having a surface and a metallization layer applied to the surface in a preparation phase of the laser machining, wherein the laser machining device comprises a laser unit for generating and emitting a laser beam and a control unit for actuating the laser unit, and the laser machining device has means for carrying out the method according to the invention.

Advantageously, the control unit comprises a computing unit and a computer program implementable on the computing unit. The computer program is preferably programmed so that the control of the laser unit can be effected by the control unit. Furthermore, the computer program is preferably programmed to enable an automated procedure of the method according to the invention.

Advantageously, the control unit is configured to generate values for the operating parameters of the laser unit. The value generation is preferably carried out on the basis of data of the workpiece to be machined.

Advantageously, the laser machining apparatus comprises an actuator for positioning and/or orienting and/or moving the laser unit. The actuator can in particular effect a movement of the laser unit in the direction X, Y, Z and/or a rotation of the laser unit about one of the axes (X, Y, Z).

Advantageously, the laser processing device comprises at least one sensor element for detecting the position and/or orientation of the workpiece.

As a further solution to the object, a computer program is proposed which is programmed for carrying out the method according to the invention when it is run on a computing unit of a control unit of a laser machining device for laser machining for removing material.

Drawings

Further features and advantages of the invention emerge from the following description, in which preferred embodiments of the invention are explained in detail with the aid of the figures. Here:

fig. 1 shows a laser machining apparatus according to the present invention;

FIG. 2 shows a schematic view of a workpiece arranged in the laser machining apparatus of FIG. 1;

fig. 3 shows a schematically illustrated flow of the method according to the invention;

fig. 4 shows a further, schematically illustrated flow of the method according to the invention;

FIG. 5 shows a cross-sectional view of a workpiece arranged for laser machining;

FIG. 6 shows a top view of a workpiece; and

fig. 7 shows a view of a workpiece being machined.

Detailed Description

Fig. 1 shows a laser machining device for laser machining of a workpiece for material removal. The laser machining apparatus is designated in its entirety by reference numeral 2. The laser processing device 2 comprises a laser unit 4 and a control unit 6 for operating the laser unit 4. The laser unit 4 is configured to generate and emit a laser beam.

In principle, the laser unit 4 for generating a laser beam may comprise, for example, a semiconductor laser, a gas laser or a solid-state laser. Preferably, it comprises a solid state laser. The solid state laser is not shown separately. For example, the solid state laser is a fiber laser.

In a fiber laser, laser radiation is guided through an optical fiber with a doped core and amplified at a resonator. Fiber lasers are generally optically pumped by coupling the radiation of a laser, in particular a diode laser, parallel to the core into its housing or into the core itself. Known doping elements for laser activation of the core are erbium, ytterbium and neodymium. After exiting from the active fiber, the laser beam mostly reaches a glass fiber or an optical fiber cable containing such a glass fiber, wherein the glass fiber directs the radiation, for example, to an optical element for focusing the laser beam.

This optical element is likewise not shown in the present invention, but it is preferably arranged in the laser unit 4. The optical element is for example a lens. According to the embodiment shown, a bundled laser beam is thus emitted from the laser unit 4.

In the working area 8 of the laser unit 4, a workpiece 10 is arranged in a machining position 12. The workpiece 10 can be arranged, for example, manually in the machining position 12. Within the scope of the automation of the method, it is also conceivable, however, to move the workpiece 10 into the processing position 12 by means of a pick-and-place robot and to place it there in the desired position and orientation.

The workpiece 10 to be machined within the scope of the invention is shown in cross section in fig. 5 and comprises a carrier element 14 made of a transparent synthetic material having a surface 16 and a metallization layer 18 applied to the surface 16. However, the carrier element 14 can also be made of an opaque synthetic material. Within the scope of the invention, the metallization layer in a relatively large-area region should be removed from the workpiece 10 by means of laser machining. In this case, damage or impairment of the transparency of the carrier element 14 should be prevented. Furthermore, the workpiece 10 has a relatively complex three-dimensional shape at least in the region of the surface 16 to be machined. The workpiece 10 arranged at the machining position 12 is loaded with a laser beam 20 generated and emitted by the laser unit 4. The region of the laser beam on the surface 16 provided with the metallization layer 18, on which the laser beam 20 impinges, is referred to as the machining point 22. At machining point 22, material of metallization layer 18 of workpiece 10 is locally removed due to an exotherm caused by the energy of laser beam 20. In particular, the metallization layer 18 is suddenly heated in the processing point 22, so that the material of the metallization layer 18 is evaporated in the processing point 22.

In order to remove material in the desired large-area region of metallization layer 18, processing point 22 is moved along a working trajectory 24 (see fig. 2). Machining point 22 is moved by moving laser beam 20 to the point of incidence on surface 16. For this purpose, the laser machining device 2 preferably comprises an actuator 26, by means of which the laser unit 4 is oriented and/or moved. The laser unit is moved linearly, in particular in the X, Y or Z direction. Alternatively or additionally, it is conceivable to rotate the laser unit about one of the axes (X, Y, Z). The actuator 26 is actuated by the control unit 6. This is indicated by the dashed line 28. The control can be performed, for example, via a radio connection between the control unit 6 and the actuator 26 or via one or more data lines (not shown). By actuating the actuator 26 with suitable actuating commands or signals by the control unit 6, the laser unit 4 is oriented and moved in such a way that the laser beam 20 and thus also the machining point 22 are moved along the desired working path 24.

It is conceivable here for not only the entire laser unit 4 or only a part of the laser unit 4 to be oriented and moved. If only a part of the laser unit 4 is moved, the laser unit comprises, for example, suitable deflection means (for example adjustable deflection mirrors), so that the emission direction of the laser beam out of the laser unit can be changed. The deflection means can be oriented and/or moved by means of the actuator 26. The movement and/or orientation of the deflection means may comprise inter alia a linear movement in the X, Y or Z direction. Alternatively or additionally, it is conceivable for the deflection means to be rotatable about one of the axes (X, Y, Z).

In addition, in the context of laser processing, the laser unit 4 is actuated by the control unit 6 such that it emits the desired laser beam 20. In particular, the power, the pulse duration and the pulse frequency of the laser beam 20 can be predetermined by suitable actuation. This actuation of the laser unit 4 by the control unit 6 is indicated in fig. 1 by a dashed line 30. The connection between the control unit 6 and the laser unit 4 can be realized, for example, by means of one or more data lines (not shown) or a radio connection (not shown).

For this purpose, control signals are transmitted to the actuator 26 and the laser unit 4 in the region of the actuator 26 and the laser unit 4 being controlled by the control unit 6. These signals are in particular correlated with values for operating parameters for operating the laser unit. The operating parameters include, for example, the position (X, Y, Z) of the laser unit, the angle of rotation, the speed at which machining point 22 moves along work trajectory 24 over surface 16, the pulse duration, the pulse frequency, and/or the power.

The values for the operating parameters can be generated, for example, by the control unit 6 itself, wherein the data of the workpiece 10 are transmitted to the control unit and the control unit accesses a database in which the operating parameters assigned to the data are stored. The data of the workpiece 10 transmitted to the control unit 6 comprise, for example, information about the workpiece 10 to be machined (for example the shape of the workpiece 10, the material and/or thickness of the metallization layer 18, the material of the carrier element 14 as data from a CAD model), information about the machining position 12 of the workpiece 10, information about the region of the metallization layer to be removed. The control unit 6 is connected to an operating unit (not shown), for example. These data can be entered by the user via the operating unit. Alternatively or additionally, these data can be transmitted to the control unit via an electronic memory interface.

Furthermore, the values for the operating parameters can be transmitted to the control unit 6, for example by loading values which have been generated and stored before the actual laser machining. In particular, a set of operating parameters can be generated for each workpiece 10 to be machined and transmitted to the control unit 6. The operating parameters are generated, for example, by means of a computing unit on the basis of data relating to the workpiece to be machined (shape of the workpiece 10, material and/or thickness of the metallization layer 18, material of the carrier element 14, information relating to the machining position 12 of the workpiece 10, information relating to a region of the metallization layer to be removed). It is also conceivable to generate operating parameters on the basis of expert knowledge and empirical values in the laser machining field. The transmission of the operating parameters takes place, for example, via the operating unit or via an electronic memory interface.

According to the embodiment shown in fig. 1, the laser machining device 2 comprises a sensor element 32. The sensor elements 32 are configured, for example, for detecting the position and/or orientation of a workpiece 10 arranged in the working region 8. The sensor element 32 is for example a contact or touch sensor or a camera. Touch sensors may be arranged in the machining position 12 and detect the position and/or orientation of the workpiece 10 in the working area 8. The camera can be arranged, for example, at a distance from the working area 8 or above it and optically detects the workpiece 10. The position and/or orientation of the workpiece 10 can be determined by evaluating the camera signals. With the sensor elements 32, it can then preferably be detected whether and how the workpiece 10 is arranged and oriented at the machining position 12. The sensor elements 32 detect data relating to the position and/or orientation of the workpiece 10 and transmit these data to the control unit 6. The data transfer between the sensor element 32 and the control unit 6 is illustrated by a dashed line 34.

The control unit 6 comprises a calculation unit 36 and a memory element 37, on which a computer program 38 is stored, which computer program can be implemented on the calculation unit 36. The operation of the laser unit 4 and the actuator 26 is performed in accordance with a computer program 38.

Fig. 2 shows a plan view onto the surface 16 to be machined of the workpiece 10. A metallization layer 18 is applied on the surface 16. A machining point 22 is depicted by way of example, in which the laser beam 20 impinges on the workpiece 10 only after the workpiece 10 has been arranged in the machining position 12. Furthermore, a region 40 on the surface 16 of the workpiece 10 is exemplarily depicted, in which the metallization layer 18 has been removed. Additionally, the metallization layer 18 should now be removed in the region 40' on the surface 16 of the workpiece 10. As already described, machining point 22 moves along work trajectory 24. In order to remove a large area of material from metallization layer 18, processing station 22 is moved along a plurality of side-by-

side working trajectories

24, 24 ', 24 "'. The working tracks 24, 24 ', 24 "' are closely side by side so that a machining point 22 'of the laser beam 20 on a first working track 24' is adjacent to or partially overlaps a machining point 22 of the laser beam on an adjacent working track 24. The working tracks 24, 24 ', 24 ", 24 '" are selected such that the desired regions 40, 40 ' of the metallization layer 18 are removed over a large area. By generating values for the operating parameters for operating the laser unit and control signals for controlling the actuators as a function of the values of the operating parameters, the laser beam 20 is moved along the working

trajectory

24, 24 ', 24 "'.

Fig. 3 and 4 each schematically show a flow chart of a method according to the invention for laser machining for material removal. According to fig. 3, in a first step 50, the workpiece 10 is arranged at a processing position 12 in the processing region 8 of the laser unit 4. In a second step 52, values for operating parameters for operating the laser unit are generated.

In a third step 54, the laser beam 20 is generated and emitted by the laser unit 4 as a function of the values generated in the second step 52 for the operating parameters. In a fourth step 56, the workpiece 10 arranged at the machining point 12 is loaded with the emitted laser beam 20 in the machining point 22. This loading results in localized material removal in processing point 22. In a fifth step 58, laser beam 20 and thus also machining point 22 are moved along working

trajectory

24, 24 ', 24 ", 24 '" depending on the generated values, so that desired region 40 ' of metallization layer 18 is removed over a large area.

In this case, it is to be noted that, in particular, steps 54 to 58 can be carried out temporally one after the other or simultaneously. Furthermore, the step 52 of generating values for the operating parameters for operating the laser unit may be carried out before or simultaneously with the first step 50 of arranging the workpiece 10 at the machining position 12.

Fig. 4 shows an exemplary flowchart of a method according to the invention, wherein, after a step 50 of arranging the workpiece 10 in the machining position 12, the position and orientation of the workpiece 10 are detected in a step 60. Based on the detected position and orientation of the workpiece 10 by means of the sensor element 32, values for the operating parameters for operating the laser unit and control signals for controlling the actuators are then generated in step 62 as a function of the values of the operating parameters. The already mentioned

steps

54, 56, 58 are then carried out.

Fig. 5 shows a cross-sectional view through an example for a workpiece 10 to be machined within the scope of the invention. The workpiece 10 comprises a carrier element 14 made of a transparent synthetic material having a surface 16 and a metallization layer 18 applied to the surface 16. Regions 40' are illustratively depicted where metallization layer 18 should be removed. The complex three-dimensional structure of the workpiece 10 can be clearly seen in fig. 5.

Fig. 6 shows another example for the workpiece 10 in its entirety. Here, too, the three-dimensional shape can be clearly recognized. Fig. 7 shows a section of the workpiece 10 from fig. 6, in which the metallization layer 18 applied to the workpiece surface 16 is removed in the region 40. The workpiece 10 in fig. 7 is backlit by a light source. It can be recognized well that the areas of the surface 16 where the metallization layer 18 is still present appear dark. In contrast, the regions 40, from which large areas of the metallization layer 18 have been removed according to the method according to the invention, appear to be illuminated.

Claims

1. A method for laser machining of a workpiece (10) for material removal, the workpiece (10) comprising a carrier element (14) made of a synthetic material having a surface (16) and a metallization layer (18) applied to the surface (16) in a preparation phase of the laser machining, wherein the laser machining is carried out by means of a laser machining apparatus (2), the laser machining apparatus (2) comprising a laser unit (4) and a control unit (6) for operating the laser unit (4), the method comprising:

-arranging the workpiece (10) in a machining position (12) in a working area (8) of the laser unit (4);

-generating values for operating parameters for operating the laser unit (5);

-generating and emitting a laser beam (20) by the laser unit (4) according to the values generated for the operating parameters;

-loading the workpiece (10) arranged in the machining position (12) with the emitted laser beam (20) in a machining point (22) in the region of a surface (16) of the workpiece (10) provided with the metallization layer (18) such that material of the metallization layer (18) is locally removed in the machining point (22);

-moving the laser beam (20) and thus also the machining point (22) relative to the workpiece (10) by means of the laser unit (4) along a working trajectory (24) in the region of the surface (16) of the workpiece (10) provided with the metallization layer (18) in accordance with the values generated for the operating parameters, so as to remove material of the metallization layer (18) along the working trajectory (24),

characterized in that the machining point (22) is moved along a plurality of adjacently arranged working tracks (24, 24 ', 24 "'), wherein the adjacent working tracks (24, 24 ') are arranged closely adjacent to one another such that the machining point (22) of the laser beam on a working track (24) adjoins the machining point (22 ') of the laser beam on an adjacent working track (24 ') or partially overlaps it in order to remove large-area material of the metallization layer (18), and the laser unit (4) is moved as a function of the values generated for the operating parameters in order to change the position of the machining point (22) and to follow the three-dimensional course of the surface (16) provided with the metallization layer (18) when driving through the working tracks (24, 24 ', 24" ').

2. Method according to claim 1, characterized in that values for the operating parameters for operating the laser unit (5) are generated and the laser unit (4) is moved as a function of the values generated for the operating parameters in such a way that the angle of the laser beam (20) in the machining point (22) relative to the surface (16) of the workpiece (10) provided with the metallization layer (18) remains constant during the travel over the working trajectory (24, 24 ', 24 "').

3. Method according to any of the preceding claims, characterized in that the laser unit (4) is moved by means of an actuator (26).

4. Method according to any of the preceding claims, characterized in that the actuator (26) is operated by the control unit (6) to move the laser unit (4).

5. Method according to any of the preceding claims, characterized in that the values for the operating parameters of the laser unit (4) are generated exclusively directly before or during the laser machining.

6. Method according to any of claims 1 to 4, characterized in that the values for the operating parameters of the laser unit (4) are generated directly before or during the actual laser machining, wherein the generation of the values for the operating parameters comprises loading the values produced before the laser machining.

7. Method according to claim 5 or 6, characterized in that the values for the operating parameters are generated from data of the workpiece (10).

8. Method according to claim 7, characterized in that the values for the operating parameters are generated as a function of information about the three-dimensional shape of the workpiece (10) and/or about the machining position of the workpiece (10) and/or about the region of the metallization layer to be removed and/or about the material and/or the thickness of the metallization layer (18) and/or about the material of the carrier element (14).

9. Method according to any one of the preceding claims, characterized in that the position and/or orientation of the workpiece (10) is detected by means of a sensor element (34) and a value for the operating parameter is generated as a function of the detected position and/or orientation.

10. Method according to any one of the preceding claims, characterized in that the laser unit (4) is operated according to a program (38) that can be implemented on the control unit (6).

11. A laser machining device (2) for laser machining of a workpiece (10) for material removal, the workpiece (10) comprising a carrier element (14) made of a synthetic material having a surface (16) and a metallization layer (18) applied to the surface (16) in a preparation phase of the laser machining, wherein the laser machining device (2) comprises a laser unit (4) for generating and emitting a laser beam (20) and a control unit (6) for operating the laser unit (4), characterized in that the laser machining device (2) has means for carrying out the method according to any one of claims 1 to 10.

12. The laser processing apparatus (2) according to claim 11, characterized in that the control unit (6) comprises a computing unit (36) and a computer program (38) implementable on the computing unit (36).

13. The laser processing apparatus (2) according to claim 11 or 12, characterized in that the control unit (6) is configured for generating values for operating parameters of the laser unit (4).

14. The laser processing apparatus (2) according to one of claims 11 to 13, characterized in that the laser processing apparatus (2) comprises an actuator (26) for the positioning and/or orientation and/or movement of the laser beam (20) and/or a processing point (22) of the laser unit (4).

15. The laser machining apparatus (2) according to one of claims 11 to 14, characterized in that the laser machining apparatus (2) comprises at least one sensor element (32) for detecting the position and/or orientation of the workpiece (10) in its machining position.

16. A computer program (38) programmed for carrying out the method according to the invention according to one of claims 1 to 10 when the computer program is run on a computing unit (36) of a control unit (6) of a laser machining apparatus (2) for laser machining of a removed material.