A laser etching device and method for large-format large-size samples

Abstract

The application provides a laser etching device and method for large-format and large-size samples, and aims to solve the technical problem that the laser processing mode of linkage of the fast axis and the slow axis of the existing galvanometer causes the non-uniform processing speed of different pattern segments due to the speed difference of the fast axis and the slow axis, and forms the splicing trace with inconsistent response speed when facing complex filled patterns. The laser etching method for large-format and large-size samples provided by the application is realized by the laser etching device for large-format and large-size samples composed of a laser scanning part, a sample movement part, a bracket and a controller, and the method of combining "trajectory decomposition + multi-layer filling" is adopted to realize the laser etching processing without splicing traces, thereby avoiding the splicing trace problem caused by the inconsistent speed response of the traditional linkage system of the fast axis and the slow axis, and ensuring the reliability and consistency of the large-area etching processing.

Description

TECHNICAL FIELD

[0001] The present application relates to a laser etching device and method, in particular to a laser etching device and method for large-format large-size samples. BACKGROUND

[0002] Laser etching is a technology that uses high-energy laser beams to etch or engrave on the surface of materials to accurately remove a portion of the material and form specific patterns, structures or textures. Laser etching is widely used in microelectronics, semiconductor manufacturing, micromachining and surface modification, and has the advantages of high precision, non-contact processing, versatility and processing flexibility.

[0003] For surface etching processing of large-format large-size samples, laser etching technology has obvious defects. Currently, laser etching systems are all achieved by using a scanning galvanometer, which needs to be matched with an f-Theta field lens. Due to the limited processing field of view, the maximum of the f-Theta field lens is 200-300mm, and the scanning galvanometer cannot completely cover the to-be-processed area of the large-format large-size sample, so the sample needs to be moved by a motion axis to move the unprocessed area to the field lens processing range for secondary processing. Because the sample needs to be moved by a motion axis for multiple processing, there are splicing marks between sample processing, which is unacceptable for high-precision processing. In addition to the galvanometer splicing processing method, there is currently a laser processing method that links the galvanometer axis and the motion axis. This processing method uses fast-slow axis linkage to solve the splicing problem of multiple processing, but for complex filled patterns, due to the difference in response speed between the fast axis and the slow axis, the acceleration and deceleration of the slow axis is much lower than that of the fast axis, causing the processing speed of different pattern segments to be uneven, resulting in splicing marks with inconsistent response speeds. The current linkage system matches the response of the fast axis with the slow axis by sacrificing efficiency, which greatly limits the application and processing efficiency of the fast-slow axis linkage. The splicing problem caused by the response speed difference of the galvanometer etching system is a key technical bottleneck that needs to be solved for realizing large-format etching processing without splicing. SUMMARY

[0004] The purpose of the present application is to solve the technical problem that the current laser processing method that links the galvanometer axis and the motion axis causes different pattern segments to have uneven processing speeds and form splicing marks with inconsistent response speeds when facing complex filled patterns, and to provide a laser etching device and method for large-format large-size samples.

[0005] In order to achieve the above-mentioned purpose, the solution of the present application is as follows:

[0006] A laser etching device for large-format large-size samples, characterized in that it comprises a laser scanning part, a sample motion part, a bracket and a controller.

[0007] The laser scanning part comprises a laser system, a Z motion shaft and a paraxial CCD; the sample motion part comprises an X motion shaft and a Y motion shaft;

[0008] The length direction of the support is defined as the X direction, the width direction is defined as the Y direction, and the height direction is defined as the Z direction; the X motion shaft, the Y motion shaft and the Z motion shaft reciprocate along the X direction, the Y direction and the Z direction respectively; the Z motion shaft, the X motion shaft and the Y motion shaft are sequentially mounted on the support from top to bottom, and the X motion shaft is connected to the motion end of the Y motion shaft;

[0009] A clamp is mounted on the upper surface of the motion end of the X motion shaft and used for clamping a sample;

[0010] The laser system and the paraxial CCD (34) are both mounted on the Z motion shaft and used for synchronous movement with the Z motion shaft in the Z direction; the laser system comprises a laser and a galvanometer deflection mirror, and the laser emitted by the laser is deflected by the galvanometer deflection mirror; the position for clamping a sample on the clamp is located on the laser light path after the laser is deflected by the galvanometer deflection mirror, and the laser acts on the surface of the sample through the galvanometer deflection mirror and is used for laser processing of the sample; the paraxial CCD uses a visual method to position the sample and obtain the positioning coordinates of the sample;

[0011] The controller stores the track of a to-be-processed drawing file and the required scanning speed value, is electrically connected with the X motion shaft, the Y motion shaft, the Z motion shaft, the paraxial CCD and the galvanometer deflection mirror respectively, is used for receiving the positioning coordinates of the sample collected by the paraxial CCD, and is used for distributing the processing coordinates of the X motion shaft, the Y motion shaft and the Z motion shaft according to the positioning coordinates of the sample in combination with a laser etching method, so as to control the movement of the X motion shaft, the Y motion shaft and the Z motion shaft in each direction and control the processing speed of the galvanometer deflection mirror, thereby realizing laser etching processing.

[0012] Further, the X motion shaft, the Y motion shaft and the Z motion shaft all adopt linear motion modules.

[0013] Further, the controller is arranged on the support.

[0014] The clamp is of an adsorption type or a mechanical type.

[0015] In addition, the application further provides a laser etching method for a large-format large-size sample, which adopts the laser etching device for a large-format large-size sample and has the following special steps.

[0016] S1, parameter calibration and sample clamping;

[0017] The control motion shaft is located at a set standard zero position, and the galvanometer deflection mirror is calibrated by dotting; then the sample is clamped on the clamp, and the sample is aligned by using the paraxial CCD; the motion shaft includes an X motion shaft, a Y motion shaft and a Z motion shaft;

[0018] S2, importing a to-be-processed graph file, and performing multi-layer straight line rotation filling;

[0019] The to-be-processed graph file is imported into the controller, and n-layer filling is performed on the to-be-processed graph file to form n-layer graphs; each layer of graph is filled with a straight line, so that the to-be-processed area of the graph generates a plurality of equidistant straight lines, and the start point and the end point of the straight line are the boundary of the graph; the direction of the straight line filled by the first layer of graph is taken as the reference line direction, and the included angle between the straight line filled by each subsequent layer of graph and the reference line is increased by a preset angle increment, so that rotation filling is formed between the n-layer graphs;

[0020] S3, graph decomposition;

[0021] Each layer of graph is decomposed into m feature points at a set interval, and m tangent lines corresponding to the m feature points are generated;

[0022] S4, calculation of graph corner matrix;

[0023] The included angle between the tangent lines corresponding to the adjacent two feature points in each layer of graph is recorded as a corner, so there are m-1 corners, and then m-1 corner vectors are obtained; the corner matrix of each layer of graph is calculated and obtained according to the m-1 corner vectors of each layer of graph;

[0024] S5, each axis coordinate and speed distribution;

[0025] The corner reference g and the processing scanning speed value u are set according to the processing requirements, and then the determination reference value M is calculated; the processing coordinates and the processing speed of the galvanometer deflection mirror and the motion shaft are distributed according to the calculated determination reference value M, to form m-1 galvanometer deflection mirror processing vectors and m-1 motion shaft processing vectors; the galvanometer deflection mirror processing matrix K of the corresponding layer is calculated according to the m-1 galvanometer deflection mirror processing vectors in each layer of graph, and the motion shaft processing matrix F of the corresponding layer is calculated according to the m-1 motion shaft processing vectors in each layer of graph;

[0026] S6, the galvanometer deflection mirror processing matrix and the motion shaft processing matrix of each layer of graph are input into the controller, and the processing parameters of the laser system are set; the controller controls the X motion shaft, the Y motion shaft and the Z motion shaft to move to the corresponding positions according to the positioning coordinates of the sample collected by the paraxial CCD 34 in step S1 and the corresponding motion shaft processing matrix F of each layer, and controls the processing speed of the galvanometer deflection mirror through the corresponding galvanometer deflection mirror processing matrix K of each layer, to complete laser etching.

[0027] Further, in step S5, the determination reference value M is calculated by the following formula:

[0028]

[0029] wherein G m is the feature point corner value in the corner matrix.

[0030] Further, in step S5, the processing coordinates and processing speed of the galvanometer deflection mirror (28) and the motion axis are allocated according to the calculated determination reference value M, specifically as follows:

[0031] It is determined whether the determination reference value M is greater than 1, if yes, the processing coordinates and processing speed of the galvanometer deflection mirror (28) and the motion axis need to be allocated; if no, only the processing speed of the galvanometer deflection mirror (28) and the motion axis need to be allocated.

[0032] Further, in step S5, the processing speed of the galvanometer deflection mirror (28) is allocated according to the following formula:

[0033]

[0034] wherein u k is the deflection speed value of the galvanometer deflection mirror after allocation, u f is the speed value of the motion axis after allocation, and H is the speed allocation ratio value.

[0035] Further, in step S5, the processing coordinates of the galvanometer deflection mirror are allocated according to the following formula:

[0036]

[0037] wherein x k is the x-direction coordinate of the galvanometer deflection mirror after allocation, y k is the y-direction coordinate of the galvanometer deflection mirror after allocation, x is the x-direction coordinate of the galvanometer deflection mirror before allocation, y is the y-direction coordinate of the galvanometer deflection mirror before allocation, R is a preset constant, and the physical meaning is the length of the trajectory extending outward along the geometric normal of the feature point, and a is the included angle between the geometric normal of the feature point and the x-direction horizontal line; and θ is the included angle between the geometric tangents corresponding to two adjacent feature points.

[0038] In step S5, the processing coordinates of the motion axis are allocated according to the following formula:

[0039]

[0040] wherein x f is the x-direction coordinate of the motion axis after allocation, y f is the y-direction coordinate of the motion axis after allocation, x is the x-direction coordinate of the motion axis before allocation, and y is the y-direction coordinate of the motion axis before allocation.

[0041] Further, in step S5, the galvanometer deflection mirror processing vector The x-direction coordinate x after being distributed by the galvanometer deflection mirror k The y-direction coordinate y after being distributed by the galvanometer deflection mirror k The speed value u after being distributed by the galvanometer deflection mirror k , which is expressed as follows:

[0042]

[0043] The motion axis processing vector The x-direction coordinate x after being distributed by the motion axis f The y-direction coordinate y after being distributed by the motion axis f The speed value u after being distributed by the motion axis f , which is expressed as follows:

[0044]

[0045] The expression of the galvanometer deflection mirror processing matrix K and the motion axis processing matrix F is respectively as follows:

[0046]

[0047]

[0048] Wherein, The m-1 galvanometer deflection mirror processing vectors are respectively, The m-1 motion axis processing vectors are respectively.

[0049] Further, in step S1, the standard zero position is a mechanical zero position or a photoelectric sensing zero position.

[0050] The beneficial effects of the present application compared with the prior art are as follows:

[0051] 1. The laser etching method for large-format large-size samples provided by the present application realizes laser etching processing without splicing marks by combining the methods of "trajectory decomposition + multi-layer filling", avoids the splicing mark problem caused by the inconsistent speed response of the traditional fast-slow axis linkage system, and ensures the reliability and consistency of large-area etching processing.

[0052] 2. The laser etching method for large-format large-size samples provided by the present application supports CAD programming and automatic operation, realizes complex pattern manufacturing, and the whole method process is simple and easy to operate, which is suitable for industrial application.

[0053] 3. The laser etching device for large-format large-size samples provided by the present application has a simple structure and is easy to operate, and is particularly suitable for large-scale laser etching engineering production application. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is a structural schematic diagram of an embodiment of a laser etching device for large-format large-size samples of the present application;

[0055] Figure 2 is a principle schematic diagram of an embodiment of a laser etching device for large-format large-size samples of the present application;

[0056] Figure 3 is a flow schematic diagram of an embodiment of a laser etching method for large-format large-size samples of the present application;

[0057] Figure 4 is a schematic diagram of three-layer pattern filling in step 2 of an embodiment of the present application;

[0058] Figure 5 is a schematic diagram of step 3 of an embodiment of the present application;

[0059] Figure 6 is a schematic diagram of mirror axis trajectory assignment in step 4 of an embodiment of the present application;

[0060] Figure 7 is a schematic diagram of motion axis trajectory assignment in step 4 of an embodiment of the present application.

[0061] Specific reference signs are as follows:

[0062] 27-Z motion axis, 28-mirror axis, 29-sample, 30-clamp, 31-X motion axis, 32-Y motion axis, 33-controller, 34-off-axis CCD, 35-support. DETAILED DESCRIPTION

[0063] In order to make the advantages and features of the present application clearer, the present application is further described in detail below in combination with the drawings and specific embodiments.

[0064] A laser etching device for large-format large-size samples, as shown in Figure 1 , includes a laser scanning part, a sample motion part, a support 35, and a controller 33, the laser scanning part and the sample motion part are physically separated and not directly connected. The laser scanning part includes a laser system, a Z motion axis 27, and an off-axis CCD 34, and the sample motion part includes an X motion axis 31 and a Y motion axis 32.

[0065] The X motion shaft 31, the Y motion shaft 32 and the Z motion shaft 27 are linear motion modules, which are composed of a motor, a guide rail, an encoder, a grating ruler and the like. The Z motion shaft 27, the X motion shaft 31 and the Y motion shaft 32 are sequentially installed on the support 35 from top to bottom, and the X motion shaft 31 is connected to the motion end of the Y motion shaft 32, and the two are combined together in a cross shape, so that linkage can be realized. The length direction of the support 35 is defined as the X direction, the width direction is defined as the Y direction, and the height direction is defined as the Z direction, so that the X motion shaft 31 moves back and forth along the X direction, the Y motion shaft 32 moves back and forth along the Y direction, and the Z motion shaft 27 moves back and forth along the Z direction.

[0066] The upper surface of the motion end of the X motion shaft 31 is provided with a clamp 30 for clamping the sample 29. In the embodiment, the sample 29 is clamped on the clamp 30 by adsorption, and the sample 29 can move synchronously with the X motion shaft 31 and the Y motion shaft 32 in the X direction and the Y direction. The laser system and the paraxial CCD 34 are installed on the Z motion shaft 27, and are used for synchronous movement with the Z motion shaft 27 in the Z direction. The laser system includes a laser and a galvanometer deflection mirror 28. The laser emitted by the laser is deflected by the galvanometer deflection mirror 28, that is, the galvanometer deflection mirror 28 controls the two-dimensional movement of the laser in the plane, including two axes U and V. The position of the clamp 30 for clamping the sample 29 is located on the laser light path after the laser is deflected by the galvanometer deflection mirror 28. The laser emitted by the laser acts on the surface of the sample 29 through the galvanometer deflection mirror 28, and is used for laser processing of the sample 29. The paraxial CCD 34 is composed of an industrial camera and a lens, and uses a visual method to position the sample 29 to obtain the positioning coordinates of the sample 29, that is, to shoot the positioning features of the sample 29. According to the position of the positioning features in the coordinate system, the coordinate position of the sample 29 is corrected, so as to obtain the positioning coordinates of the sample 29.

[0067] Since the laser system and the paraxial CCD 34 are installed on the Z motion shaft 27, in the positioning process, the Z motion shaft 27 needs to move up and down to drive the paraxial CCD 34 to move to the required clear positioning position, that is, the position at which the sample 29 can be clearly shot. In the processing process, the Z motion shaft 27 needs to move up and down to drive the galvanometer deflection mirror 28 to move, so that the processing focal point position of the galvanometer deflection mirror 28 coincides with the position of the sample 29.

[0068] As shown in FIG. 1, the laser system and the paraxial CCD 34 are installed on the Z motion shaft 27, and the Z motion shaft 27 is installed on the support 35. Figure 2As shown, the controller 33 stores the track of the to-be-processed drawing file and the required scanning speed value, and is electrically connected with the X motion axis 31, the Y motion axis 32, the Z motion axis 27, the side-axis CCD 34 and the galvanometer deflection mirror 28, respectively, for receiving the positioning coordinates of the sample 29 collected by the side-axis CCD 34, and distributing the processing coordinates of the X motion axis 31, the Y motion axis 32 and the Z motion axis 27 according to the positioning coordinates of the sample 29 in combination with the laser etching method, so as to control the movement of the X motion axis 31, the Y motion axis 32 and the Z motion axis 27 in each direction, and control the processing speed of the galvanometer deflection mirror 28, thereby realizing the laser etching processing. In the embodiment, the controller 33 is placed on the support 35.

[0069] Based on the above laser etching device for large-format and large-size samples, the present application further provides a laser etching method for large-format and large-size samples, which comprises the following steps: Figure 3 As shown, the method specifically comprises the following steps:

[0070] S1, parameter calibration and sample clamping.

[0071] First, the motion axis is controlled to be located at the set standard photoelectric sensing zero point position, so as to ensure the initial coordinate system reference datum of the sample 29. The motion axis includes the X motion axis 31, the Y motion axis 32 and the Z motion axis 27. Then, the galvanometer deflection mirror 28 is calibrated by dotting, specifically, the galvanometer deflection mirror 28 is dotted according to the predetermined interval, the actual measured interval after dotting is measured by using a standard measuring device, and the actual measured interval is compared with the predetermined interval for calibration, thereby completing the initialization of the galvanometer deflection mirror 28. Finally, the sample 29 is clamped on the clamp 30, and the sample 29 is aligned by using the side-axis CCD 34.

[0072] S2, importing the to-be-processed drawing file and performing multi-layer straight line rotation filling.

[0073] The to-be-processed drawing file is imported into the controller 33, and the to-be-processed drawing file is a closed graph in the format of dxf, dwg, etc. In the present application, the to-be-processed drawing file is filled in multiple layers to form multiple layer graphs, each layer graph is filled with straight lines, and the multiple layer graphs are filled with rotation.

[0074] The straight line filling refers to generating a plurality of equidistant straight lines in the to-be-processed area of the graph at a predetermined interval, and the start point and the end point of the straight line are the boundary of the graph. In the processing process, the laser moves along the plurality of equidistant straight lines, and the multiple lines process the surface of the sample 29 in parallel. The interval between the adjacent straight lines should be less than the diameter of the laser spot, so as to ensure that the to-be-processed plane of the sample 29 is completely covered by the laser.

[0075] The straight line direction filled by the first layer of patterns is taken as the reference line direction, and the included angle between the straight line filled by each subsequent layer of patterns and the reference line is increased by a preset angle increment, so that the multiple layers of patterns are formed by rotational filling, which aims to homogenize the stitching marks caused by inconsistent speed responses and ensure the uniformity of the final processing. In this embodiment, the filled pattern layers are three, the straight line L1 direction filled by the first layer of patterns is taken as the reference line direction, and the included angle between the straight line filled by each subsequent layer of patterns and the reference line is increased by an angle increment of 60 degrees; as shown in Figure 4 , the included angle between the straight line L1 filled by the first layer of patterns and the reference line is 0 degrees, the included angle between the straight line L2 filled by the second layer of patterns and the reference line is 60 degrees, and the included angle between the straight line L3 filled by the third layer of patterns and the reference line is 120 degrees. The spacing between any two adjacent straight lines in each layer of patterns is 0.008 mm.

[0076] S3, pattern decomposition.

[0077] Each layer of patterns is decomposed into 11 feature points according to a set spacing, and 11 geometric tangent lines corresponding to the 11 feature points are generated. The set spacing is a length unit, which represents the pattern length between two adjacent feature points, as shown in Figure 5 , one of the feature points is denoted as feature point A, and one of the adjacent feature points is denoted as feature point B. The set spacing is the pattern length between the feature point A and the feature point B. The straight line C and the straight line D are the geometric tangent lines corresponding to the feature point A and the feature point B, respectively. The set spacing is determined according to the complexity of the pattern. If the pattern is large and smooth as a whole, the set spacing is set to be large. If the pattern is small or has many features as a whole, the set spacing is set to be small. In this embodiment, the size of the pattern is 20x20 mm, and 100 circles with a diameter of 0.35 mm are uniformly distributed in the pattern. Therefore, the set spacing is set to be 0.1 mm.

[0078] S4, calculation of pattern corner matrix.

[0079] As shown in Figure 5 , the included angle θ between the geometric tangent lines corresponding to two adjacent feature points in each layer of patterns is denoted as a corner. The x coordinate, the y coordinate and the included angle θ of the pattern form a corner vector It is worth noting that the included angle θ in the present application is an acute angle formed after the intersection of two geometric tangent lines. In this embodiment, each layer of patterns has 11 feature points, so each layer of patterns has 10 corners, each corner corresponds to a corner vector, and a total of 10 corner vectors are obtained All the corner vectors of each layer of patterns form a corner matrix G, and three layers of patterns form corner matrices G1, G2 and G3, respectively.

[0080] S5, axis coordinate and speed distribution.

[0081] S5.1, set the corner reference g and the processing scanning speed value u according to different processing requirements, and calculate the judgment reference value M according to the following formula:

[0082]

[0083] In the formula, G m is the corner value of the feature point in the corner matrix.

[0084] For processing with high corner requirement, the corner reference g is usually set smaller, and for processing with low corner requirement, the corner reference g is usually set larger. In the embodiment, the corner reference g is 20 degrees, and the processing scanning speed value u is 400 mm / s. In the embodiment, the M value corresponding to the initial feature point of each layer of the pattern is 3.

[0085] S5.2, distribute the processing coordinates and processing speed of the galvanometer deflection mirror 28 and the motion shaft according to the calculated judgment reference value M.

[0086] The processing coordinates and processing speed of the galvanometer deflection mirror 28 and the motion shaft refer to the mapping of the deflection speed of the galvanometer deflection mirror 28 and the motion speed of the motion shaft. First, it is judged whether the judgment reference value M is greater than 1, if yes, the processing coordinates and processing speed of the galvanometer deflection mirror 28 and the motion shaft need to be distributed, if not, only the processing speed of the galvanometer deflection mirror 28 and the motion shaft need to be distributed.

[0087] The processing speed distribution formula of the galvanometer deflection mirror 28 and the motion shaft is as follows:

[0088]

[0089] In the formula, u k is the deflection speed value of the galvanometer deflection mirror 28 after distribution, u f is the speed value of the motion shaft after distribution, H is the speed distribution ratio, if M is less than 0, H is a preset constant D. The following is an example of a parameter, D is 0.9. If M is greater than 0, the calculation formula of H is:

[0090]

[0091] It can be seen that the greater the corner of the pattern, the greater the M value, and the H value is also correspondingly greater, and the distribution speed of the galvanometer deflection mirror 28 is greater. Due to the advantage of extremely small inertia of the galvanometer deflection mirror 28, the speed distribution at the corner should tend to the galvanometer deflection mirror 28. Conversely, the smaller the corner of the pattern, the smaller the M value, and the smaller the H value, and the distribution speed of the motion shaft is greater, which can better realize the smooth processing of large format and large size samples. In the embodiment, D is 0.9, M value is 3, and H value is calculated to be 0.6, the final speed value u k of the galvanometer deflection mirror 28 after distribution is 240 mm / s, and the speed value uf The speed of the motion axis is 160 mm / s, and the speed of the motion axis is distributed to the X motion axis 31 and the Y motion axis 32 according to the trajectory direction of the drawing to be processed.

[0092] The machining coordinate allocation formula for galvanometer deflector 28 is as follows:

[0093]

[0094] In the formula, x k The x-coordinates and y-coordinates of the galvanometer deflector 28 are assigned to the galvanometer deflector 28. k y is the y-coordinate after the galvanometer deflector 28 is assigned, x is the x-coordinate before the galvanometer deflector 28 is assigned, y is the y-coordinate before the galvanometer deflector 28 is assigned, R is a preset constant, which physically means the length of the trajectory extending outward along the geometric normal of the feature point, and α is the angle between the geometric normal of the feature point and the horizontal line in the x-direction.

[0095] like Figure 6 As shown, a feature point on the initial trajectory S of the drawing to be processed is selected as the initial feature point E. The geometric normal of the initial feature point E is denoted as the feature point normal F, and the straight line passing through the initial feature point E along the X direction is denoted as the horizontal line L of the galvanometer axis. In the normal direction, the initial feature point E is calculated by the above formula to form the assigned galvanometer axis feature point E′. The difference between the initial feature point E and the assigned galvanometer axis feature point E′ is the change in the galvanometer axis feature point. The value of the change in the galvanometer axis feature point is sinθ × R. For a relatively smooth graphic with zero corners, the sinθ term is zero, and the coordinates of the galvanometer deflector 28 after assignment are consistent with the coordinates before assignment, so trajectory optimization is not required. For a graphic with abrupt changes, the sinθ term is a constant between 0 and 1. The coordinates of the galvanometer deflector 28 in the x and y directions extend outward along the normal direction based on the original coordinates, and the trajectory changes in the direction of larger corners, giving full play to the advantage of the small inertia of the galvanometer deflector 28. The larger the corner, the greater the outward extension. The maximum angle is 90°, at which point the sinθ term value is 1, and the extended length is equal to the preset constant R value. In this embodiment, the preset constant R value is 0.5mm. The angle between the feature point normal F and the horizontal line L of the galvanometer axis is denoted as α. The normal distance of the trajectory extension is allocated to the x and y directions through the angle α between the feature point normal F and the horizontal line L of the galvanometer axis, used to update the machining coordinates of the galvanometer axis feature point E′ in the x and y directions after allocation. The change in the galvanometer axis feature point is projected in the x and y directions respectively to obtain the change in the x direction Δx and the change in the y direction Δy of the galvanometer axis. The coordinates of the galvanometer axis feature point E′ in the x direction after allocation are the coordinates of the initial feature point E in the x direction plus the change in the galvanometer axis in the x direction Δx. The coordinates of the galvanometer axis feature point E′ in the y direction after allocation are the coordinates of the initial feature point E in the y direction plus the change in the galvanometer axis in the y direction Δy.

[0096] After all feature points on the initial trajectory S are assigned processing coordinates according to the above method, the resulting trajectory M is the motion trajectory of the galvanometer deflector 28, and the motion trajectory of the galvanometer deflector 28 is on the outer convex side of the initial trajectory S.

[0097] The formula for assigning machining coordinates to the motion axis is:

[0098]

[0099] In the formula, x f Assigning x-coordinates and y-coordinates to the motion axes f Here, x represents the y-coordinate after the motion axis has been assigned, and y represents the x-coordinate before the motion axis has been assigned.

[0100] like Figure 7 As shown, the same feature point on the initial trajectory S is selected as the initial feature point E. The geometric normal of the initial feature point E is denoted as the feature point normal F. The straight line passing through the initial feature point E along the X direction is denoted as the horizontal line of the motion axis P, which is the same straight line as the horizontal line of the galvanometer axis L. In the normal direction, the initial feature point E is calculated by the above formula to form the motion axis feature point E″ after allocation. The difference between the initial feature point E and the motion axis feature point E″ after allocation is the change of the motion axis feature point. The value of the change of the motion axis feature point is sinθ×R. Its parameters are basically consistent with the allocation of the galvanometer deflection mirror 28. For the motion axis, since the inertia is small, the trajectory allocation needs to be smoother. Therefore, the coordinates after allocation are the original coordinates minus the normal term. That is, the trajectory changes in the direction of smaller corners, and the trajectory of the motion axis changes in the direction of concavity. The larger the corner, the greater the length of concavity, so as to achieve the effect of smoothing the trajectory of the motion axis. The angle between the feature point normal F and the horizontal line P of the motion axis is denoted as β. The normal distance of the concave trajectory is allocated to the x and y directions through the angle β between the feature point normal F and the horizontal line P of the motion axis. This is used to update the machining coordinates of the motion axis feature point E″ in the x and y directions after allocation. The change in the motion axis feature point is projected in the x and y directions respectively to obtain the change in the x direction Δx′ and the change in the y direction Δy′ of the motion axis. The coordinates of the motion axis feature point E″ in the x direction after allocation are the coordinates of E in the x direction plus the change in the x direction Δx′ of the motion axis. The coordinates of the motion axis feature point E″ in the y direction after allocation are the coordinates of E in the y direction plus the change in the y direction Δy′ of the motion axis.

[0101] After all the feature points on the initial trajectory S are assigned machining coordinates according to the above method, the resulting trajectory N is the motion trajectory of the motion axis, which is on the concave side of the initial trajectory S.

[0102] Galvanometer deflector machining vector The motion axis machining vector is composed of the x-coordinate, y-coordinate, and velocity value assigned by the galvanometer deflector 28. The x-direction coordinate, y-direction coordinate and velocity value after distribution by the motion axis, whose formulas are respectively shown as follows:

[0103]

[0104]

[0105] Since there are 10 corners on each layer of the pattern in the embodiment, each corner corresponds to a galvanometer deflection mirror machining vector and a motion axis machining vector, and thus there are 10 galvanometer deflection mirror machining vectors and 10 motion axis machining vectors. The 10 galvanometer deflection mirror machining vectors are respectively denoted as The 10 motion axis machining vectors are respectively denoted as The galvanometer deflection mirror machining matrix K of each layer of the pattern is The motion axis machining matrix F is

[0106] S6, the galvanometer deflection mirror machining matrix K and the motion axis machining matrix F of each layer of the pattern are respectively input into the controller 33, and the machining process parameters of the laser system, such as the focal point position, the laser power, the laser frequency and the like, are set. The controller 33 controls the X motion axis 31, the Y motion axis 32 and the Z motion axis 27 to move to the corresponding positions according to the positioning coordinates of the sample 29 collected by the side-axis CCD 34 in step S1 and the corresponding motion axis machining matrix F of each layer, and controls the machining speed of the galvanometer deflection mirror 28 through the corresponding galvanometer deflection mirror machining matrix K of each layer, to complete the laser etching.

[0107] The present application adopts two technical means to improve the splicing problem caused by the difference in response speed, one is to perform corner decomposition on the pattern to be machined to form a corner matrix of the pattern, to distinguish the corner difference of different pattern segments, and to decompose the corner pattern track into a corner track and a smooth track for the place with larger corner, to assign the corner track to the galvanometer axis with better speed response and the smooth track to the motion axis with poor speed response, to adapt to the axis system with different speed response. The other is to optimize the filling mode of the pattern, to perform etching machining in a multi-layer rotary filling mode, and to homogenize the splicing traces. The laser etching machining by the above technical means not only takes the advantage of large motion amplitude of the motion axis without multiple machining splicing traces, but also solves the problem of poor speed response of the motion axis which cannot match the galvanometer axis. The speed response consistency of machining is ensured, and the splicing problem caused by the difference in speed response in the traditional linkage machining method is completely solved.

[0108] The above merely aims to explain the technical solutions of the present application, and is not intended to limit the same. Those skilled in the art can make modifications to the specific technical solutions described in the above embodiments, or make equivalent replacements to some of the technical features, and these modifications or replacements do not cause the corresponding technical solutions to deviate from the scope of the technical solutions protected by the present application.

Claims

1. A method of laser engraving a large format large size sample, characterized in that, The method comprises the following steps: S0, a laser etching device is built; the laser etching device comprises a laser scanning part, a sample movement part, a support (35) and a controller (33); the laser scanning part comprises a laser system, a Z movement shaft (27) and a paraxial CCD (34); the sample movement part comprises an X movement shaft (31) and a Y movement shaft (32); the Z movement shaft (27), the X movement shaft (31) and the Y movement shaft (32) are sequentially installed on the support (35) from top to bottom, and the X movement shaft (31) is connected to a movement end of the Y movement shaft (32); a clamp (30) is installed on an upper surface of the movement end of the X movement shaft (31); the laser system and the paraxial CCD (34) are both installed on the Z movement shaft (27); the laser system comprises a laser and a galvanometer deflection mirror (28), and the laser emitted by the laser is deflected by the galvanometer deflection mirror (28); a position for clamping a sample (29) on the clamp (30) is located on a laser light path after the laser is deflected by the galvanometer deflection mirror (28); S1, parameter calibration and sample clamping; the X movement shaft (31), the Y movement shaft (32) and the Z movement shaft (27) are respectively controlled to be located at set standard zero point positions, and the galvanometer deflection mirror (28) is dot-marked; then the sample (29) is clamped on the clamp (30), and the paraxial CCD (34) is used to align the sample (29); S2, import a to-be-processed drawing file, and perform multi-layer straight line rotation filling; the to-be-processed drawing file is imported into the controller (33), and the to-be-processed drawing file is filled with n layers to form n layers of patterns; each layer of pattern is filled with a straight line to generate a plurality of equidistant straight lines in the to-be-processed area of the pattern, and the start point and the end point of the straight line are the boundaries of the pattern; a direction of the straight line filled by the first layer of pattern is taken as a reference line direction, and an included angle between the straight line filled by each subsequent layer of pattern and the reference line is increased by a preset angle increment, so that rotation filling is formed between the n layers of patterns; S3, pattern decomposition; each layer of pattern is decomposed into m feature points at a set interval, and m tangent lines corresponding to the m feature points are generated; S4, calculation of pattern corner matrix; an included angle between tangent lines corresponding to two adjacent feature points in each layer of pattern is recorded as a corner, so that there are m-1 corners, and then m-1 corner vectors are obtained; a corner matrix of each layer of pattern is calculated according to the m-1 corner vectors of each layer of pattern; S5, distribution of each axis coordinate and speed; a determination reference value M is calculated by the following formula: wherein G m is a feature point corner value in the corner matrix; the processing coordinates and the processing speed of the galvanometer deflection mirror (28) and the movement shaft are distributed according to the calculated determination reference value M, to form m-1 galvanometer deflection mirror processing vectors and m-1 movement shaft processing vectors; specifically, whether the determination reference value M is greater than 1 is determined, if yes, the processing coordinates and the processing speed of the galvanometer deflection mirror (28) and the movement shaft need to be distributed, and if not, only the processing speed of the galvanometer deflection mirror (28) and the movement shaft needs to be distributed. According to the m-1 galvanometer deflection mirror processing vector calculation of each layer of pattern, the corresponding layer of galvanometer deflection mirror processing matrix K is obtained; according to the m-1 motion axis processing vector calculation of each layer of pattern, the corresponding layer of motion axis processing matrix F is obtained; S6, the galvanometer deflection mirror processing matrix and the motion axis processing matrix of each layer of pattern are input into the controller respectively, and the processing parameters of the laser system are set; the controller (33) controls the X motion axis (31), the Y motion axis (32) and the Z motion axis (27) to move to the corresponding positions respectively according to the positioning coordinates of the sample (29) collected by the side-axis CCD 34 in step S1 and the corresponding motion axis processing matrix F of each layer, and controls the processing speed of the galvanometer deflection mirror (28) through the corresponding galvanometer deflection mirror processing matrix K of each layer, so as to complete the laser etching.

2. The laser etching method of a large-format large-size sample according to claim 1, characterized in that: In step S5, the processing speed distribution formula of the galvanometer deflection mirror (28) is as follows: wherein u k is the deflection speed value assigned to the galvanometer deflection mirror (28), u f is the speed value assigned to the motion axis, and H is the speed assignment ratio.

3. The laser etching method of a large-format large-size sample according to claim 2, characterized in that: In step S5, the processing coordinate distribution formula of the galvanometer deflection mirror (28) is as follows: wherein x k is the x-direction coordinate assigned to the galvanometer deflection mirror (28), y k is the y-direction coordinate assigned to the galvanometer deflection mirror (28), x is the x-direction coordinate before assignment to the galvanometer deflection mirror (28), y is the y-direction coordinate before assignment to the galvanometer deflection mirror (28), R is a preset constant, the physical meaning of which is the length of the trajectory extending along the geometric normal of the feature point, and a is the included angle between the geometric normal of the feature point and the x-direction horizontal line; and θ is the included angle between the geometric tangents corresponding to two adjacent feature points. In step S5, the processing coordinate distribution formula of the motion axis is as follows: In the formula, x f is the x-direction coordinate after assignment of the motion axis, y f is the y-direction coordinate after assignment of the motion axis, x is the x-direction coordinate before assignment of the motion axis, and y is the y-direction coordinate before assignment of the motion axis.

4. The laser etching method of a large-format large-size sample according to claim 3, characterized in that: In step S5, the galvanometer deflector mirror processes the vector The x-direction coordinate x after distribution by the galvanometer deflector mirror (28) k The y-direction coordinate y after distribution by the galvanometer deflector mirror (28) k The velocity value u after distribution by the galvanometer deflector mirror (28) k The expression is as follows: The motion axis processing vector The x-direction coordinate x after motion axis assignment f The y-direction coordinate y after motion axis assignment f The velocity value u after motion axis assignment f The expression is as follows: The expression of the galvanometer deflection mirror processing matrix K and the motion axis processing matrix F is as follows respectively: wherein, are m-1 galvanometer deflection mirror machining vectors, respectively, are m-1 motion axis machining vectors, respectively.

5. The laser etching method of a large-format large-size sample according to claim 1, characterized in that: In step S1, the standard zero point position is a mechanical zero point position or a photoelectric sensing zero point position.

6. The laser etching method of a large-format large-size sample according to claim 1, characterized in that: In step S0, the X motion axis (31), the Y motion axis (32) and the Z motion axis (27) all adopt linear motion modules.

7. The laser etching method of a large-format large-size sample according to claim 6, characterized in that: In step S0, the controller (33) is arranged on the support (35); The clamp (30) is an adsorption type clamping or a mechanical type clamping.

Images