Method for removing regions of a layer applied to a substrate

Abstract

The invention relates to a method for removing at least one region (1) of a layer (3) applied to a substrate (2), wherein a respective region (1) to be removed is machined in such a way that at least one linear recess (5) is made in the layer (3) at least in sections along an outer contour (4) of the region (1) by the layer (3) being removed using a laser beam and the region (1) thereby being at least thermally separated from adjacent areas of the layer (3). Energy is then introduced into the region (1) using the laser beam, until there is a reduction in adhesion and / or the layer (3) becomes detached in the region (1). Adjacent regions (1), between the successive machining of which the laser cutting tool and the substrate (2) move relative to each other, are additionally machined in such a way that a tolerance compensation zone (6) is formed between these adjacent regions (1).

Description

[0001] Method for removing areas of a layer applied to a substrate

[0002] The invention relates to a method for removing at least one region of a layer applied to a substrate. In this process, each region to be removed is processed in such a way that at least one linear recess is introduced into the layer, at least in sections along an outer contour of the region. The layer is ablated using a laser beam, thereby at least thermally separating the region from adjacent areas of the layer. Energy is then applied to the region using the laser beam until a reduction in adhesion and / or detachment of the layer in the region is achieved.

[0003] A variety of methods for producing structured and, in particular, conductive layers on a substrate, such as a circuit board, are known in the art. Etching and milling processes are considered the most widely used. However, both methods have significant disadvantages, especially in the area of ​​prototype construction.

[0004] Milling processes are time-consuming and costly compared to other methods, particularly due to the limited dynamics of the milling machines used. These challenges are exacerbated when dealing with complex or densely packed structuring patterns. In addition, milling often results in the substrate underlying the layer to be structured being exposed to adverse effects, as it is usually removed to achieve the necessary separation and / or isolation of structures on the substrate. Depending on the substrate, e.g., a circuit board made of a class FR4 composite material, this process can also generate particles that can not only impair the service life of the milling tools used but are also considered a health hazard. Therefore, effective extraction is required.

[0005] Although etching processes generally offer shorter production times, these advantages are relativized, especially in the area of ​​prototype construction. Etching processes can also be associated with disadvantages, such as a lack of structural accuracy and potential inaccuracies in the etching. Etching can pose difficulties in achieving high precision in very fine structures. The accuracy of the resulting structuring is limited due to underetching, for example, especially when complex designs with fine details are required. Furthermore, inhomogeneities in the etching solution can lead to uneven etching, especially with large-area substrates. This, in turn, can lead to undesirable variations in the structure dimensions. Above all, etching processes are associated with a high environmental impact, as aggressive etching solutions are often used.The etching products resulting from the etching solutions and the removed materials are also often highly polluting. Proper handling and disposal of these chemicals are essential to minimize environmental impacts, which entails high costs.

[0006] The use of laser systems for structuring layers on a substrate has become established, particularly for prototype construction and small-scale production. Such laser systems can create detailed structures in layers by precisely removing or cutting the layer material. This enables, among other things, rapid prototype development and the production of small batches without the need for expensive tool modifications, as can be required with conventional manufacturing methods. This also eliminates the need for particularly environmentally harmful processes. The use of laser systems enables high precision and flexibility, but exhibits weaknesses when it comes to removing material over large areas. The small beam diameter leads to longer processing times, despite the use of galvanometer scanners.If the substrate also has a comparable or even lower ablation threshold than the layer to be removed, there is a risk of unacceptable damage. The low ablation threshold of the substrate limits the possible energy input, meaning that when large-area material is removed, the conductive layer is not completely evaporated but melted and displaced, leading to material accumulation. In this case, the laser energy is no longer sufficient to reliably remove the conductive layer. Increasing the laser energy is again impossible to prevent damage to the substrate. To solve this problem, DE 10 2004 006414 A1 describes a method for detaching a region of a conductive layer from a substrate. The region is first thermally insulated by creating a linear recess along its circumference. This step is carried out using a laser beam.The area to be removed is then heated by the laser beam until the adhesion of the conductive layer to the substrate is significantly reduced in that area, allowing the area to be detached from the substrate. Detachment then occurs under low adhesion forces, influenced by gravity or external forces, preventing the substrate from being exposed to further laser exposure. Preferably, the area is detached using a targeted supply of compressed air, which allows the conductive layer to be lifted from the edge to the center of the surface. Alternatively, the area to be detached can first be divided into subsections instead of being removed as a whole.

[0007] DE 102010 019406 A1 represents a further development of the previously described process. Here, the areas of a conductive layer to be removed are always divided into strip-shaped sections. The orientation of the thermally insulating recesses is chosen such that these, and thus also the insulated sections, never run parallel to the main axes of the structures to be formed in the layer. Instead, they always meet the structures at an acute angle. This prevents parallel thermal energy input, which significantly reduces unwanted energy effects on the structures. This minimizes or even eliminates the likelihood of damage to the structures.

[0008] Furthermore, it is known that laser systems can usually only process a section of a substrate using their galvanometer scanners, as these only cover a limited scan field. Thus, for complete processing, relative movement between the processing laser tool and the substrate must be provided via a traversing unit to link multiple scan fields. Adjacent scan fields must be connected as seamlessly as possible, which is particularly challenging with small structure dimensions. Otherwise, discontinuities arise between the scan fields, resulting in gaps or overlaps between the structures to be connected. Overlaps, in particular, pose the risk of unacceptable damage to the substrate due to excessive energy input.A precise connection between the scanning fields requires complex calibration of the traversing unit while maintaining extremely tight tolerances. Prior art approaches to address this problem are already known. For example, DE 10 2010 019 407 A9 describes a method for creating recesses in an electrically conductive layer formed on a substrate, such as those found in circuit boards. These recesses serve to electrically insulate structures such as conductor tracks and are created in the layer using a laser beam. The specific problem that arises is that the ends of a single recess or of two different recesses do not meet seamlessly when created using a laser beam.In order to nevertheless achieve effective insulation across at least one recess, it is proposed that the end sections of the recess run parallel and deliberately offset from one another. With a sufficiently small offset between the two end sections, the mere introduction of the recess into the layer causes a high thermal energy input into the zone between the end sections. This leads to a reduction in the adhesion of the layer in this zone and also enables automatic, undefined detachment of the layer between the end sections. It is also conceivable that the detachment is assisted after the adhesion has been reduced. The method is therefore disadvantageously only suitable for compensating small deviations. The undefined detachment also means a lack of control over the detachment process.Without a clear definition and control of the detachment behavior, there is a risk of unpredictable results and thus undesirable damage.

[0009] DE 10 2010 019 407 A9 also describes the formation of separating lines that are generated in the functional layers deposited on a transparent substrate during the manufacture of a photovoltaic module with series-connected cells. Laser scanners are used for this purpose, whose laser beam creates several adjacent separating line sections in the functional layer in the field scanned by it. The laser scanners are then moved relative to the coated substrate in the direction of the separating lines by a distance slightly smaller than the length of the scanned field to allow the fields to overlap in this direction. To create continuous separating lines, the individual separating line sections of each separating line must also be precisely aligned with one another.

[0010] Against this background, the invention is based on the object of designing a method of the type mentioned above in such a way that reliable removal of areas of the layer with tolerances that are the same or higher than those of the prior art, thus enabling simplified calibration and preventing unacceptable damage. This object is achieved according to the invention by a method according to the features of claim 1. The further embodiment of the invention is set out in the subclaims.

[0011] According to the invention, a method is provided for removing at least one region of a layer, in particular an electrically conductive layer, which is initially applied to a substrate over its entire surface. The laminated layer, for example, is preferably formed as a copper layer. The substrate itself can, for example, consist of a printed circuit board material, such as a composite material of class FR4. In one embodiment, the substrate and layer would therefore be formed as a copper-clad printed circuit board or a printed circuit board blank, respectively. In an alternative embodiment, however, the substrate can also be a film, e.g., a polyimide film. Furthermore, a glass substrate is also conceivable.

[0012] By removing at least two or more regions, a structure with a defined, preferably predetermined, profile is created in the layer. This structure has characteristic main axes that are at right angles to each other. The structure can, for example, comprise at least one conductor track or a group of conductor tracks of a circuit board layout.

[0013] Furthermore, the invention provides that a respective region of the layer to be removed is processed in such a way that at least one linear recess and / or interruption is introduced into the layer at least along a section, or at least in sections along an outer contour of the region. Preferably, however, the introduction of the at least one, preferably exclusively one, recess takes place along the entire outer contour of the region.

[0014] According to the invention, the at least one recess is created by ablating the layer using a laser beam, whereby the region is completely separated from adjacent areas of the layer, at least thermally, but preferably by means of a material bond. Energy is then introduced into the region using the laser beam until a reduction in adhesion and / or detachment of the layer in the region is achieved. To ablate the layer and thus form the at least one recess, the laser beam would be focused on the layer, with the focus of the laser beam therefore lying on and / or in the layer. In order to reduce the adhesion of the layer in the relevant area or even to cause the layer to detach, it would be conceivable for the laser beam to strike the layer in a defocused manner.In this way, the layer in the area in question is essentially only heated, but not removed.

[0015] Furthermore, according to the inventive embodiment, two adjacent regions, between whose successive processing a relative movement of the laser cutting tool and the substrate occurs, are processed in such a way that a tolerance compensation zone, in particular a strip-shaped one, is formed or remains between these regions, which initially remains at least thermally connected to adjacent areas of the layer. Consequently, a section of the layer extends between the adjacent regions, which compensates for the tolerances between the regions resulting from the relative movement. This extremely advantageously opens up the possibility of considering higher tolerances during the relative movement than would be possible without the presence of the tolerance compensation zone.This also eliminates the need to machine the areas so that they lie directly next to each other, and the recesses separating the areas must overlap as precisely as possible. Furthermore, because overlapping is not necessary, unacceptable damage to the substrate can be avoided.

[0016] When machining at least one of the adjacent regions, but in particular both adjacent regions, the energy input into the respective region and thus into the tolerance compensation zone, especially when creating the recess in the layer, is such that, in a further development of the method according to the invention, adhesion of the layer in the tolerance compensation zone is essentially maintained. The low energy input into the layer of the tolerance compensation zone advantageously enables subsequent, controlled removal of the tolerance compensation zone, since an uncontrolled and undefined reduction in adhesion or detachment is avoided. This helps to maintain the desired control over the process of reducing adhesion or detachment and to minimize undesirable effects. In particular, uncontrolled detachment can lead to unacceptable damage to the adjacent regions or other areas of the layer.In addition, an uncontrolled detached layer of the tolerance compensation zone could redeposit in neighboring areas or other regions of the layer. This would potentially have negative effects on the processing of other areas and / or could cause impermissible connections, such as short circuits between structures formed on the substrate, for example, conductor tracks. To significantly reduce adhesion or to detach the tolerance compensation zone, an additional energy input into the layer of the tolerance compensation zone would therefore be necessary. Thus, one embodiment of the invention also provides for the tolerance compensation zone to be removed, in particular only after the neighboring areas have been processed, and the neighboring areas are thereby connected to form a single area.This advantageously maintains control over the removal of the tolerance compensation zone and enables targeted control of the process of joining the adjacent areas. This inevitably contributes to minimizing or avoiding the undesirable effects already described during the removal of the tolerance compensation zone.

[0017] In a further development of the method according to the invention, it is therefore generally provided, but particularly in connection with the embodiment explained above, that in order to remove the tolerance compensation zone, the tolerance compensation zone is in particular initially machined in such a way that at least one linear recess and / or interruption is introduced into the layer, at least in sections along an outer contour of the tolerance compensation zone. This is achieved by ablating the layer using the laser beam, and the tolerance compensation zone is thereby at least thermally separated from adjacent areas of the layer. Subsequently, energy is again introduced into the tolerance compensation zone using the laser beam until a reduction in adhesion and / or detachment of the layer in the tolerance compensation zone is achieved.The tolerance compensation zone is thus machined in the same way as the areas to be removed. This enables efficient machining of the tolerance zone and the adjacent areas using a single device, such as a laser processing system. This integration leads to significant savings in process costs, as no separate equipment is required for machining the tolerance compensation zone, and contributes to increased efficiency of the overall process.

[0018] A special embodiment of the method according to the invention, in particular of the above development, comprises that in order to remove the tolerance compensation zone, at each of its two desired ends lying in a main extension direction of the tolerance compensation zone, in particular exclusively at least one linear recess and / or interruption is introduced into the layer, which runs transversely or perpendicularly to the main extension direction of the tolerance compensation zone. The main extension direction of the tolerance compensation zone generally corresponds to a longitudinal extension of the tolerance compensation zone, wherein the main extension direction generally runs parallel to at least one of the main axes of a structure to be introduced into the layer. Furthermore, within the scope of the embodiment, it can be considered that, in particular, only one or two recesses are introduced into the layer at each desired end.Generally speaking, the fact that recesses are introduced, particularly exclusively at the desired ends in the main direction of extension, advantageously minimizes the processing time and thus the process costs. Additional recesses, necessary for at least thermally separating the tolerance zone along its entire outer contour, would already be introduced into the layer by machining the adjacent areas. Furthermore, the only one-time energy input to create the additional recesses during machining of the adjacent areas prevents unacceptable damage to the substrate.

[0019] An advantageous embodiment of the invention also involves introducing the linear recesses at the desired ends of the tolerance compensation zone into the layer as an extension of recesses in one or both of the adjacent regions. This not only leads to improved homogeneity of the recesses but also minimizes the likelihood of excessive discontinuities or overlaps between the regions and the tolerance compensation zone.

[0020] For clarification purposes, it should be explained again in the above context that the recesses at the desired ends of the tolerance compensation zone are also created, in particular, by ablating the layer using a laser beam. Furthermore, in this case, too, energy is subsequently introduced into the tolerance compensation zone, preferably using the laser beam, until a reduction in adhesion and / or detachment of the layer in the tolerance compensation zone is achieved.

[0021] A further embodiment of the invention also resides in the fact that a scanning field that can be covered by the laser cutting tool, within which the laser beam can be deflected by the laser cutting tool and which at least partially encompasses a respective region during its processing, is designed to slightly overlap, abut, or be slightly spaced from a scanning field formed or present before the relative movement. Due to the formation of the tolerance compensation zone between adjacent regions, all of the aforementioned positions of the scanning fields relative to one another that potentially occur after the relative movement can be compensated for, in particular within wide limits. This ensures a high level of robustness of the method with respect to potential tolerances of a device carrying out the method, e.g., a laser cutting system.

[0022] As already explained at the beginning, by removing regions of the layer, at least one structure with a fixed, in particular predetermined, course is formed from the layer. In this context, a further development of the invention is designed such that a main extension direction, preferably a longitudinal extension of the tolerance compensation zone, is aligned parallel to at least one of the main axes of the structure determined by the course of the structure. This alignment generally contributes to a substantially optimal result when connecting the adjacent regions to form an overall region. The main axes of the structure indicate the, in particular two, main extension directions of the structure or parts of the structure, for example the conductor tracks of a circuit board layout, and are oriented at right angles to one another.

[0023] An extremely advantageous embodiment of the method according to the invention can also be seen in that a respective area is divided into sub-areas for removal, wherein the sub-areas are at least thermally separated from one another by at least one linear recess and / or interruption being introduced into the layer at least in sections along an outer contour of a respective sub-area by ablating the layer using the laser beam and then energy is introduced into the respective sub-area by means of the laser beam until a reduction in adhesion and / or detachment of the layer in the respective sub-area is achieved. The recesses run essentially along, in particular, parallel straight lines. Dividing a respective area into sub-areas leads to increased process reliability and process control.Furthermore, the energy input required to reduce adhesion and / or detach the layer in a particular sub-area can be more precisely controlled than is possible for an entire area. Due to their smaller surface area compared to a complete area, the sub-areas also represent a smaller heat sink, thus reducing any heat flow, particularly into the substrate, and resulting in lower energy losses. Thus, the required energy input for all sub-areas of a region can be determined to be lower than for the complete area.

[0024] A design of the invention is also advantageous if a main extension direction, in particular a longitudinal extension of the subregions, is not aligned parallel to any of the main axes and / or angle bisectors of the main axes of the structure determined by the course of the structure. Rather, the subregions are aligned with their main extension direction at an acute or obtuse angle to the main axes and / or angle bisectors of the main axes of the structure. This allows the input of energy into the subregions to be further optimized, since due to this orientation of the subregions to be removed from the substrate relative to the structure remaining on the substrate, heat flow from the subregions into the surrounding areas of the layer is minimized.

[0025] It should also be noted that it is fundamentally possible that the actual or final removal of the layer of the regions, sub-regions and / or tolerance compensation zone from the substrate is achieved solely by introducing energy into the layer of the respective region, sub-region and / or tolerance compensation zone.

[0026] In a preferred embodiment of the invention, the actual or final - planar - removal of the layer of a respective region, sub-region and / or tolerance compensation zone from the substrate, however, takes place under an external influence on the layer of the region and / or sub-region, which influence differs in particular from the energy input of the laser beam. The influence could, for example, be the force of gravity acting on the layer, for which purpose one layer side of the substrate is preferably aligned in the direction of the acting force of gravity. More advantageous, however, is an influence resulting from a targeted supply of compressed air, wherein a targeted jet of compressed air enables the lifting and thus removal of the conductive layer, preferably starting from the edge towards the center of the respective region, sub-region and / or tolerance compensation zone.An effect resulting from suction as well as magnetic and / or electrostatic forces is also conceivable.

[0027] It should also be explained that the width of the aforementioned subregions and / or the tolerance compensation zone, which is formed in particular transversely to the main extension direction of the subregions and / or the tolerance compensation zone, depends significantly on the optical design and / or—thus—on the optical parameters of a laser processing system implementing the method. Specifically, the width, especially a minimum width of the subregions and / or the tolerance compensation zone, is influenced by the beam diameter of the defocused laser beam, which is therefore essentially determined by the optical design and / or the optical parameters of the laser processing system.As already explained, the defocused laser beam introduces energy, which primarily leads to heating and thus contributes to a significant reduction in adhesion and / or detachment of the layer in the partial areas and / or a respective tolerance compensation zone. In addition to the beam diameter of the defocused laser beam, the width of the partial areas and / or the tolerance compensation zone also depends on a safety and / or correction factor, so the width is as follows:

[0028] Width (mm) = beam diameter (mm) x correction factor

[0029] The beam diameter of the defocused laser beam depends on the focus diameter of the focused laser beam, the defocus, and the depth of field of the laser beam around the focus point of the laser beam as follows: z \ T-. > > > z \ . (Defocus (mm))

[0030] Beam diameter (mm) = focus 2 v Jdiameter (mm) x 1 H - - - - - - V (depth of field (mm) / 2) 2

[0031] Defocusing describes a shift of the focal point from the focal length of a focusing lens and / or focusing optics of the laser processing system and is regularly determined from empirical values. The focus diameter of the focused laser beam, in turn, depends on the focal length of the focusing lens and / or focusing optics, the wavelength of the laser beam, and the diffraction coefficient M. 2 and the diameter of the laser beam at the focusing lens and / or focusing optics and is calculated as:

[0032] 4 x focal length (mm) x wavelength (mm) x diffraction index focus diameter (mm) = - - - — - - - - - - - - - -

[0033] TT x diameter of laser beam at focusing lens (mm)

[0034] The diffraction index M 2represents the inverse of the beam quality K. The depth of field is also determined by:

[0035] 2TT x (focus diameter (mm) / 2) 2

[0036] Depth of field (mm) =

[0037] Wavelength (mm)

[0038] The following two examples illustrate the determination of the width of the partial areas and / or the tolerance compensation zone using the above calculation rules: Example 1 :

[0039] Example 2:

[0040] It should also be noted that the width of the partial regions and / or the tolerance compensation zone is in particular in a range from 40 micrometers to 250 micrometers, preferably 80 micrometers to 180 micrometers and / or particularly preferably 100 micrometers to 160 micrometers.

[0041] Furthermore, it should be noted that, within the scope of the invention, at least thermal separation is considered to mean a significant minimization of a heat flow caused at least by thermal conduction between a respective region, subregion, and / or the tolerance compensation zone and adjacent areas of the layer and / or between subregions. The invention permits various embodiments. To further clarify its basic principle, one of these is illustrated in the drawing and described below.

[0042] The drawing shows in Figures 1 to 3 a basic sequence of an embodiment of the method according to the invention.

[0043] Figure 1 initially shows how the regions 1 are processed so that the two adjacent regions 1 shown, or the layer 3 in these regions 1, can be removed from the substrate 2. For this purpose, at least one linear recess 5 is introduced into the layer 3, at least in sections along the outer contour 4 of the respective region 1, wherein the two adjacent regions 1 are also divided into subregions 11. This is also achieved by introducing at least one linear recess 5 into the layer 3 along the outer contour 12 of a respective subregion 11.As a result, the partial regions 11 are at least thermally and preferably completely separated from each other, as well as the respective complete region 1 from adjacent areas of layer 3, so that there is no material bond within layer 3 between the partial regions 11 and region 1 and other areas of layer 3, and thus a significantly increased thermal resistance, in particular by layer 3 itself, is formed. For this purpose, the recesses 5 are designed as interruptions, in particular in the form of cuts that completely sever layer 3.

[0044] The respective recesses 5 are created in layer 3 by ablating layer 3 using a laser beam (not shown in detail), for which the laser beam is focused on layer 3. Subsequently, energy is also introduced into the respective partial area 11 and thus sectionally into the entire area 1 using the laser beam, until a reduction in adhesion and / or detachment of layer 3 in the respective partial area 11 and thus also sectionally across the entire area 1 is achieved. The energy is introduced along the illustrated heating paths 14, which are followed by the defocused laser beam and are aligned in the respective main extension direction 13 of the partial areas 11. In this way, layer 3 in the relevant area 1 or the respective partial areas 11 is merely heated, but not ablated.

[0045] As can also be seen from Figure 1, the two adjacent regions 1 and thus the respective associated sub-regions 11 lie in different scanning fields 10, whereby only one of the scanning fields 10 can be covered at a time by a laser cutting tool generating the laser beam. As a result, a relative movement occurs between the laser cutting tool and the substrate 2 between the processing of the two regions 1. However, this relative movement can introduce tolerances into the positioning of the two adjacent regions 1 relative to one another, which, when one of the regions 1 is processed following the relative movement, hinder a reliable connection of the two regions 1 and / or lead to unacceptable damage to the substrate 2 or other areas of the layer 3.

[0046] To avoid this problem, the two adjacent regions 1 are machined in such a way that the tolerance compensation zone 6 is formed or remains between them. The adhesion of layer 3 in the tolerance compensation zone 6 is initially maintained during the machining of regions 1. After machining and / or even removal of one of the regions 1 or both regions 1, the tolerance compensation zone 6 is also removed, and the adjacent regions 1 are thereby connected to form an overall region. Either layer 3 is no longer present in the overall region, or layer 3 of the relevant sub-regions 11 and the tolerance compensation zone 6 can be successively removed.

[0047] How the tolerance compensation zone 6 is machined for removal is shown in detail in Figures 2 and 3. For this purpose, two linear recesses 5 are made in the layer 3 in sections along the outer contour 7 of the tolerance compensation zone 6 and in particular at each of its two desired ends 9 located in the main extension direction 8 of the tolerance compensation zone 6, said recesses running transversely to the main extension direction 8 of the tolerance compensation zone 6. For reasons of illustration, only one of the two desired ends 9 is shown in Figures 1 to 3. The linear recesses 5 at the desired ends 9 of the tolerance compensation zone 6 are also made in the layer 3 as an extension of recesses 5 in the two adjacent regions 1, thus ensuring efficient machining of the tolerance compensation zone 6. The recesses 5 are again made by ablation using the laser beam.

[0048] As can also be seen from Figures 2 and 3, the two scanning fields 10 formed before and after the relative movement are slightly spaced from one another. However, due to the tolerances resulting from the relative movement, the recesses 5 of the tolerance compensation zone 6 extending from the regions 1 are not completely connected to one another and / or do not overlap. It should be noted that the offset between the recesses 5 in the illustrations in Figures 2 and 3 is exaggerated for illustrative purposes only and is therefore not to scale. However, the recesses 5 still thermally separate the tolerance compensation region 6 from the other surrounding areas of the layer 3 and the regions 1, since there is a sufficiently high thermal resistance.

[0049] Thus, the introduction of energy by means of the laser beam along the heating path 14 following the introduction of the recesses 5, which is shown in Figure 3, also leads to a reduction in the adhesion and / or a detachment of the layer 3 in the tolerance compensation zone 6, so that the layer 3 of the tolerance compensation zone 6 is removed or becomes removable. The heating path 14 lies in the main extension direction 8 of the tolerance compensation zone 6, wherein this main extension direction 8 runs parallel to one of the main axes x, y, here the main axis y. The main axes x, y are defined by the fixed, in particular predetermined course of a structure which is formed by removing the regions 1 from the layer 3. The main extension direction 13 of the partial regions 11, on the other hand, is not parallel to one of the two main axes x, y.

[0050] REFERENCE SYMBOL LIST

[0051] 1 area

[0052] 2 Substrat

[0053] 3 layer

[0054] 4 Outer contour

[0055] 5 Recess

[0056] 6 T olerance compensation zone

[0057] 7 Outer contour

[0058] 8 Main direction of extension

[0059] 9 Target end

[0060] 10 Scan field

[0061] 11 sub-area

[0062] 12 Outer contour

[0063] 13 Main direction of extension

[0064] 14 Heating path x, y main axis

Claims

PATENT CLAIMS E 1. A method for removing at least one region (1) of a layer (3) applied to a substrate (2), wherein a respective region (1) to be removed is processed in such a way that at least one linear recess (5) is introduced into the layer (3) at least in sections along an outer contour (4) of the region (1), by ablating the layer (3) by means of a laser beam and thereby at least thermally separating the region (1) from adjacent areas of the layer (3), wherein energy is subsequently introduced into the region (1) by means of the laser beam until a reduction in adhesion and / or a detachment of the layer (3) in the region (1) is achieved, characterized in that adjacent regions (1), between the successive processing of which a relative movement of the laser cutting tool and the substrate (2) takes place, are processed in such a waythat a tolerance compensation zone (6) is formed between these adjacent areas (1).

2. Method according to claim 1, characterized in that adhesion of the layer (3) in the tolerance compensation zone (6) is maintained during machining of at least one of the adjacent regions (1).

3. Method according to claim 1 or 2, characterized in that the tolerance compensation zone (6) is removed after machining the adjacent regions (1) and the adjacent regions (1) are thereby connected to form an overall region.

4. Method according to at least one of the preceding claims, characterized in that the tolerance compensation zone (6) is processed for removal in such a way that at least one linear recess (5) is introduced into the layer (3) at least in sections along an outer contour (7) of the tolerance compensation zone (6) by removing the layer (3) by means of the laser beam and the tolerance compensation zone (6) is thereby at least thermally separated from adjacent areas of the layer (3), wherein subsequently, energy is introduced into the tolerance compensation zone (6) by means of the laser beam until a reduction in adhesion and / or detachment of the layer (3) in the tolerance compensation zone (6) is achieved.

5. Method according to at least one of the preceding claims, characterized in that the tolerance compensation zone (6) is processed for removal in such a way that at least one linear recess (5) is introduced into the layer (3) at each of its two desired ends (9) lying in the main extension direction (8), which recess runs transversely to the main extension direction (8) of the tolerance compensation zone (6).

6. Method according to at least one of the preceding claims, characterized in that the linear recesses (5) at the desired ends (9) of the tolerance compensation zone (6) are introduced into the layer (3) in extension of recesses (5) of one of the adjacent regions (1) or of both adjacent regions (1).

7. Method according to at least one of the preceding claims, characterized in that a scanning field (10) which can be covered by the laser cutting tool and which at least partially encompasses a respective region (1) during its processing is designed to be slightly overlapping, abutting or slightly spaced from a scanning field (10) formed before the relative movement.

8. Method according to at least one of the preceding claims, characterized in that by removing regions (1) at least one structure with a defined course is formed from the layer (3), wherein a main extension direction (8) of the tolerance compensation zone (6) is aligned parallel to at least one of the main axes (x, y) of the structure determined by the course of the structure.

9. Method according to at least one of the preceding claims, characterized in that a respective region (1) is divided into partial regions (11) for removal, the partial regions (11) being at least thermally separated from one another by at least one linear recess (5) being made in the layer (3) at least in sections along an outer contour (12) of a respective partial region (11) by ablating the layer (3) by means of the laser beam and then energy is introduced into the respective partial region (11) by means of the laser beam until a reduction in the adhesion and / or a detachment of the layer (3) in the respective partial region (11) is achieved.

10. Method according to at least one of the preceding claims, characterized in that a main extension direction (13) of the partial regions (11) is not aligned parallel to any of the main axes (x, y) determined by the course of the structure and / or angle bisectors of the main axes (x, y).

11. Method according to at least one of the preceding claims, characterized in that the removal of the layer (3) of a respective region (1), partial region (11) and / or respective tolerance compensation zone (6) from the substrate (2) takes place under an external influence on the layer (3) in question.

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