Laser micro-hole machining device and method with mirror-assisted layer-by-layer trimming

Abstract

The application discloses a kind of laser micro-hole processing equipment and method of mirror auxiliary layering trimming, equipment includes laser source, mirror scanning component, laser cutting head, Z direction focusing component, rough cutting movement component and controller.Processing, first control laser beam and workpiece generate rough cutting relative motion, remove the main body material in target micro-hole, form the rough hole of the hole wall margin relative to target hole wall reservation;After rough hole processing is completed, the hole wall of rough hole is divided into multiple trimming layers along hole depth direction, and the corresponding hole edge compensation profile is determined according to the target hole wall profile at the corresponding depth of each trimming layer;Depth position of laser focal point is adjusted in turn, and scanning is carried out along the corresponding hole edge compensation profile by mirror scanning component, to remove the hole wall margin at corresponding trimming layer layer by layer.The application can consider micro-hole processing efficiency and hole wall processing quality, improve the aperture consistency of deep micro-hole and hole wall profile precision.

Description

Technical Field

[0001] This invention belongs to the field of laser precision machining technology, specifically relating to a laser micro-hole machining equipment and method for galvanometer-assisted layer trimming. Background Technology

[0002] Laser micro-hole processing is widely used in the micro-hole processing of metals, ceramics, glass, semiconductors, and polymer materials due to its non-contact nature, high processing precision, and wide applicability. With the increasing demands for micro-hole processing quality in products such as medical devices, fuel injectors, filters, electronic packaging, and microfluidic devices, not only is high processing efficiency required, but also higher standards are being placed on the consistency of micro-hole diameter, hole wall roughness, hole wall taper, and orifice contour quality.

[0003] In current laser micro-hole machining processes, high energy or large feed rates are typically used for rapid processing to quickly remove the main material inside the hole in order to improve material removal efficiency. However, this processing method is prone to defects such as contour fluctuations, burrs, recast layers, or localized edge chipping at the hole opening and wall, and may also cause hole wall streaks and inconsistencies in hole diameter and taper along the hole depth direction. If a lower energy and smaller removal rate are used for fine scanning from the beginning of processing to improve micro-hole quality, a large number of repeated scans are required, significantly increasing the processing time and making it difficult to balance processing efficiency and processing quality.

[0004] Furthermore, for micro-holes with a certain aspect ratio, the laser focus has a limited effective depth. When contour scanning is performed only on the workpiece surface or at a fixed depth, it is difficult to ensure that different depth positions of the hole wall are within a suitable focusing and energy density range. Especially when the hole wall formed by rough machining itself has a certain diameter deviation or taper error, it is difficult to effectively compensate for the actual machining allowance at different depth positions by using a uniform scanning trajectory to trim the entire hole wall.

[0005] Therefore, how to perform targeted fine finishing on different depth positions of the hole wall after rough machining while ensuring the removal efficiency of the main material of the micropore, so as to improve the consistency of the micropore diameter, the quality of the hole wall contour and the processing efficiency, is a problem that needs to be further solved in the existing laser micro-hole processing technology. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a galvanometer-assisted layered trimming method for laser micro-hole processing. This method solves the problems in existing laser micro-hole processing, such as the difficulty in balancing the efficiency of material removal and the quality of hole wall processing, as well as the difficulty in maintaining a suitable focusing state and performing targeted hole wall trimming at different depth positions for micro-holes with a certain depth-to-diameter ratio.

[0007] The technical solution provided by this invention is as follows: On the one hand, a laser micro-hole processing method with galvanometer-assisted layered trimming includes the following steps: S1. Determine the target hole wall contour and hole depth of the target micro-hole to be processed; S2. Control the laser beam to generate a rough cutting relative motion with the workpiece, remove the main material inside the target micro-hole, form a coarse hole, and make the hole wall of the coarse hole retain a hole wall margin relative to the target hole wall towards the inside of the hole. S3. After the rough hole is processed, the hole wall is divided into multiple trimming layers along the hole depth direction, and the corresponding hole edge compensation contour is determined according to the target hole wall contour at the corresponding depth of each trimming layer. S4. Adjust the depth position of the laser focus according to the processing order of multiple trimming layers, so that the laser focus is positioned sequentially to the corresponding trimming layer, and drive the laser spot to scan along the hole edge compensation contour corresponding to the trimming layer through the galvanometer scanning component, so as to remove the hole wall excess at the corresponding trimming layer layer by layer to form the hole wall of the target microhole.

[0008] Optionally, the hole edge compensation profile is determined based on one or more of the following: target hole diameter at the corresponding trimming layer, target hole wall taper, hole wall allowance, measured profile of the coarse hole, effective laser spot size, and kerf compensation amount.

[0009] Optionally, the hole edge compensation profiles corresponding to at least two trimming layers have different profile dimensions to compensate for the diameter variation of the coarse hole along the hole depth direction and / or form a target micropore with a predetermined hole wall taper.

[0010] Optionally, the effective laser processing depth ranges corresponding to adjacent trimming layers partially overlap, and the interlayer spacing between trimming layers is determined based on one or more of the Rayleigh length of the laser focus, the material removal depth, and the taper of the target hole wall.

[0011] Optionally, after the rough hole is machined, at least one of the following is obtained: the orifice profile, the hole wall features, and the hole outlet features; When the orifice contour is obtained, the positional deviation of the coarse hole relative to the scanning center of the galvanometer is determined based on the orifice contour, and the scanning center of the galvanometer scanning assembly is corrected accordingly. When at least one of the hole wall features and hole outlet features is obtained, at least one of the hole diameter and taper of the coarse hole is determined based on the obtained results, and the hole edge compensation profile of the corresponding trimming layer is corrected accordingly.

[0012] Optionally, the single-pulse energy used in the trimming process is lower than that used in the roughing process, and the contour scanning speed of the trimming process is higher than that of the roughing process.

[0013] On the other hand, a laser micro-hole processing device with galvanometer-assisted layered trimming includes a laser source, a galvanometer scanning assembly, a laser cutting head, a Z-axis focusing assembly, a roughing motion assembly, and a controller; The galvanometer scanning assembly is located on the light-incident side of the laser cutting head. The output light path of the galvanometer scanning assembly is connected to the focusing light path of the laser cutting head, so that the laser beam deflected by the galvanometer scanning assembly is focused by the laser cutting head and then incident on the workpiece. The Z-axis focusing component is used to change the depth position of the laser focus relative to the workpiece; The coarse cutting motion assembly is used to generate a coarse cutting relative motion between the laser beam and the workpiece to remove the bulk material inside the target microhole and form a coarse hole that retains a wall allowance relative to the target hole wall. The controller is connected to the laser source, the galvanometer scanning assembly, the Z-axis focusing assembly, and the coarse cutting motion assembly, and is configured to: after the coarse hole is processed, divide the hole wall of the coarse hole into multiple trimming layers along the hole depth direction, and determine the corresponding hole edge compensation contour according to the target hole wall contour at the corresponding depth of each trimming layer; control the Z-axis focusing assembly to position the laser focus sequentially to each trimming layer, and control the galvanometer scanning assembly to drive the laser spot to scan along the corresponding hole edge compensation contour to remove the hole wall excess at the corresponding trimming layer layer by layer.

[0014] Optionally, the galvanometer scanning assembly is fixedly connected to the laser cutting head, or the galvanometer scanning assembly and the laser cutting head are mounted on a common rigid mounting bracket.

[0015] Optionally, a beam relay component is provided between the galvanometer scanning component and the focusing component of the laser cutting head. The beam relay component makes the equivalent scanning turning point of the galvanometer scanning component and the entrance pupil surface of the focusing component form a conjugate relationship. Z-axis focusing assembly includes at least one of the following: a linear module for driving at least one of the laser cutting head and the workpiece to move along the Z-axis; and a dynamic focusing lens assembly disposed in the laser optical path.

[0016] Optionally, it also includes a detection component, which includes an imaging detection unit for acquiring the orifice contour and / or orifice wall features of the coarse orifice. The controller is connected to the detection component and corrects the scanning center of the galvanometer scanning component and / or the orifice edge compensation contour of the corresponding trimming layer based on the detection results of the detection component.

[0017] In summary, the beneficial effects of this invention are: (1) In this invention, the main material inside the target micropore is first removed by rough cutting, and the resulting coarse hole wall retains a wall allowance relative to the target hole wall. After the rough hole is processed, the coarse hole wall is divided into multiple trimming layers along the hole depth direction. By adjusting the depth position of the laser focus, the laser focus is sequentially aligned with different trimming layers, and the galvanometer scanning assembly is used to scan along the hole edge compensation contour corresponding to each trimming layer. Thus, the rough cutting mainly undertakes the rapid removal of large volume materials, while the galvanometer scanning mainly undertakes the fine trimming of small hole wall allowances, reducing the processing time required to remove all the material inside the hole using fine scanning, and improving the hole wall processing quality while taking into account processing efficiency.

[0018] (2) In this invention, the laser focus can be adjusted sequentially along the depth of the hole with the trimming layer, so that different depth positions such as the hole opening, the middle of the hole wall and the hole exit can be in the appropriate laser action area, reducing the problem of inconsistent processing state at different depth positions of the hole wall due to the fixed focus, which is beneficial to improving the hole diameter consistency, hole wall roughness and hole wall taper of deep micro-holes.

[0019] (3) Each trimming layer of the present invention can determine the hole edge compensation profile according to the target hole wall profile and hole wall margin at the corresponding depth, so that the corresponding scanning trajectory is adopted at different depth positions, thereby enabling layered compensation for the hole diameter change or taper deviation of the coarse hole along the hole depth direction, and improving the consistency between the final microhole wall and the target hole wall profile.

[0020] (4) In the case of obtaining the outline of the coarse hole opening, hole wall features or hole outlet features, the present invention can also correct the hole edge compensation outline of the galvanometer scanning center and the corresponding trimming layer according to the actual detection results, thereby reducing the influence of the rough cutting position deviation and hole wall processing error on the subsequent trimming accuracy and improving the adaptability and stability of the micro-hole processing process. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram of the optical path where the galvanometer scanning assembly is located above the laser cutting head. Figure 3 A cross-sectional schematic diagram showing the hole wall allowance and multiple trimming layers set along the hole depth; Figure 4 A top-view schematic diagram showing the coarse hole profile, the target hole profile, and the multi-loop compensation scan trajectory; Figure 5 This is a schematic diagram showing the connection between the controller and each functional component.

[0022] Figure label: 1. Frame; 2. Laser source; 21. Beam shaping assembly; 3. Galvanometer scanning assembly; 31. Beam relay assembly; 32. Galvanometer mounting bracket; 4. Laser cutting head; 41. Focusing assembly; 42. Processing nozzle; 5. Workpiece motion platform; 6. Workpiece fixture; 7. Workpiece; 71. Rough hole profile; 721-726. Trimming layer; 73. Hole wall allowance; 74. Target hole profile; 75. Compensating scanning trajectory; 76. Scanning center; 8. Controller; 9. Z-axis focusing assembly; 10. Imaging and displacement detection assembly. Detailed Implementation

[0023] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. The following embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0024] Example 1

[0025] like Figures 1 to 5 As shown, a laser micro-hole processing device with galvanometer-assisted layer trimming includes a frame 1, a laser source 2, a galvanometer scanning assembly 3, a laser cutting head 4, a workpiece motion platform 5, a workpiece fixture 6, a controller 8, a Z-axis focusing assembly 9, and a detection assembly 10.

[0026] The workpiece motion platform 5 is mounted on the frame 1, and the workpiece fixture 6 is mounted on the moving end of the workpiece motion platform 5. The workpiece 7 to be processed is fixed on the workpiece fixture 6. The workpiece motion platform 5 can drive the workpiece 7 to move relative to the laser processing position. In this embodiment, the workpiece motion platform 5 constitutes a specific implementation of the roughing motion assembly.

[0027] Specifically, the workpiece motion platform 5 may include an X-axis linear module and a Y-axis linear module arranged perpendicularly to each other. Through the linkage of the X-axis linear module and the Y-axis linear module, the workpiece 7 can move relative to the laser focus along a predetermined coarse cutting trajectory, thereby causing the laser beam and the workpiece 7 to generate coarse cutting relative motion.

[0028] Laser source 2 is used to generate the processing laser. The laser beam output from laser source 2 can first pass through beam shaping component 21 for beam expansion, collimation or spot shaping, and then enter galvanometer scanning component 3. Depending on the material, thickness, micro-hole size and processing accuracy requirements of the workpiece 7 to be processed, laser source 2 can be a nanosecond pulse laser, picosecond pulse laser or femtosecond pulse laser.

[0029] The galvanometer scanning assembly 3 is located on the light-incident side of the laser cutting head 4. The galvanometer scanning assembly 3 can be directly fixedly connected to the laser cutting head 4, or it can be installed together with the laser cutting head 4 on the galvanometer mounting bracket 32 ​​or other rigid mounting structure, so that the galvanometer scanning assembly 3 and the laser cutting head 4 maintain a stable mechanical and optical positional relationship, thereby reducing the impact of equipment movement, vibration or temperature changes on their relative positional relationship.

[0030] The galvanometer scanning assembly 3 includes two scanning mirrors that can deflect in different directions. The scanning directions of the two scanning mirrors intersect each other, preferably orthogonally. By coordinating the deflection of the two scanning mirrors, the laser spot can perform a two-dimensional high-speed scan within the processing area of ​​the workpiece 7.

[0031] The output optical path of the galvanometer scanning assembly 3 is connected to the focusing optical path of the laser cutting head 4. The laser cutting head 4 includes a focusing assembly 41 and a processing nozzle 42 located on the light-emitting side of the focusing assembly 41. The laser beam, after being deflected by the galvanometer scanning assembly 3, enters the focusing assembly 41 and is focused by the focusing assembly 41 before being directed towards the workpiece 7 by the processing nozzle 42.

[0032] A beam relay component 31 can be provided between the galvanometer scanning assembly 3 and the focusing assembly 41. The beam relay component 31 is used to relay the laser beam output by the galvanometer scanning assembly 3 and to make the equivalent scanning turning point of the galvanometer scanning assembly 3 and the entrance pupil surface of the focusing assembly 41 conjugate, thereby reducing the positional change of the laser beam at the entrance pupil of the focusing assembly 41 during the galvanometer scanning process and improving the consistency of the focal spot size and incident state at different scanning positions.

[0033] Z-axis focusing assembly 9 is used to change the depth position of the laser focus relative to the workpiece 7. In one embodiment, the Z-axis focusing assembly 9 includes a Z-axis linear module connected to the laser cutting head 4, which drives the laser cutting head 4 to move up and down along the Z-axis to change the depth position of the laser focus.

[0034] In another embodiment, the Z-axis focusing assembly 9 may include a linear module for driving the workpiece 7 to move along the Z-axis, adjusting the depth position of the laser focus within the workpiece 7 by changing the relative height between the workpiece 7 and the laser cutting head 4.

[0035] In other embodiments, the Z-axis focusing assembly 9 may further include a dynamic focusing lens group disposed in the laser optical path, which changes the axial position of the laser focal point by adjusting the optical state of the dynamic focusing lens group. The above-mentioned mechanical focusing method and optical focusing method can be used alone or in combination.

[0036] The detection component 10 is used to detect position or contour information related to micro-hole machining. The detection component 10 may include an imaging detection unit for acquiring the area to be machined, the outline of the coarse hole opening, and / or hole wall features on the workpiece 7. The detection component 10 may also include a displacement detection unit for detecting the height position of the workpiece 7 surface to determine the initial position of the laser focus relative to the workpiece 7 surface.

[0037] The controller 8 is connected to the laser source 2, the galvanometer scanning assembly 3, the workpiece motion platform 5, the Z-axis focusing assembly 9, and the detection assembly 10 respectively. It is used to coordinate the laser output, the rough cutting relative motion, the galvanometer scanning, and the depth adjustment of the laser focus, so that the micro-hole processing can proceed to the rough hole processing stage and the hole wall layer trimming stage in sequence.

[0038] Example 2

[0039] This embodiment illustrates the basic process of micro-hole processing using the aforementioned laser micro-hole processing equipment.

[0040] First, the target hole wall profile and hole depth are determined based on the material, thickness, and product design requirements of the workpiece 7 to be processed. The target microhole can be a circular hole, an elliptical hole, a polygonal hole, or other irregularly shaped holes; the hole wall of the target microhole can be a straight wall or have a predetermined taper.

[0041] Before processing begins, the position to be processed on the workpiece 7 and the surface height of the workpiece 7 can be determined by the detection component 10, and the starting position of the roughing process and the initial position of the laser focus can be determined accordingly.

[0042] Then, rough hole machining is performed.

[0043] The controller 8 controls the laser source 2 to output the processing laser and controls the workpiece motion platform 5 to move the workpiece 7 relative to the laser focus, so as to remove the main material inside the target micro-hole. The roughing motion trajectory can adopt a spiral trajectory, a concentric contour trajectory, a circle-by-circle contour trajectory, or a grid trajectory.

[0044] During the roughing process, the hole wall is not directly machined to the final target hole wall position. Instead, the formed rough hole contour 71 is located inside the target hole contour 74, so that the hole wall of the rough hole retains a hole wall allowance 73 relative to the target hole wall towards the inside of the hole.

[0045] Therefore, the roughing stage mainly aims to quickly remove the main material inside the target micropore, rather than directly obtaining the final hole wall size and quality at this stage. Processing parameters with high material removal efficiency can be used to quickly form coarse holes, while retaining a hole wall allowance of 73 for subsequent hole wall finishing.

[0046] In this embodiment, the completion of the coarse hole processing means that the main material inside the target microhole, which was handled by the rough cutting stage, has been removed according to the predetermined plan, and a coarse hole has been formed for subsequent layer-by-layer trimming of the hole wall. After the coarse hole is formed, the layer-by-layer trimming stage begins. The subsequent processing mainly targets the removal of the hole wall allowance 73 remaining between the coarse hole wall and the target hole wall, rather than forming the hole depth by removing the main material inside the target microhole layer by layer.

[0047] If the target microhole is a through hole, a coarse hole that penetrates the workpiece 7 can be formed by rough cutting. If the target microhole is a blind hole, the coarse hole can be machined to a predetermined depth corresponding to the target hole depth, and then the hole wall can be trimmed in layers.

[0048] The dimensions of the coarse hole and the hole wall allowance 73 can be determined based on the workpiece material, workpiece thickness, target hole diameter, target hole depth, laser focal spot size, roughing machining accuracy, and target hole wall quality. For example, in some micro-hole machining scenarios, the target micro-hole diameter can be 10–1000 μm, and the hole wall allowance 73 can be 2–50 μm. The above values ​​are only examples and can be adjusted according to the actual machining object and process requirements.

[0049] Example 3

[0050] like Figure 3 As shown, after the rough hole is machined, the hole wall is divided into multiple trimming layers 721 to 726 along the hole depth direction.

[0051] Each trimming layer corresponds to a depth region on the wall of the coarse hole. The number of trimming layers and the spacing between adjacent trimming layers can be determined based on the target hole depth, the effective processing depth of the laser focus, the material removal depth, and the taper of the target hole wall.

[0052] In one embodiment, the effective laser processing depth ranges of adjacent trimming layers partially overlap, so that the hole wall area between two adjacent trimming layers can be effectively treated by the laser, thereby reducing the possibility of forming annular steps or interlayer marks due to insufficiently processed areas between different trimming layers.

[0053] Specifically, the basic layer spacing can be determined based on the Rayleigh length of the focused laser beam, and further adjusted in conjunction with the effective removal depth of the workpiece material during the single-layer trimming process. For areas with large errors in the hole opening, hole exit, or coarse hole wall, the layer spacing between adjacent trimming layers can be reduced, making the trimming layers in that area more densely packed.

[0054] Multiple trimming layers do not necessarily need to be spaced at equal intervals. For example, when the hole wall size and quality are relatively stable in the middle of a coarse hole, a larger layer spacing can be set; at the hole inlet, hole outlet, or where the diameter of the coarse hole changes significantly, a smaller layer spacing can be set.

[0055] For each trimming layer, determine the hole edge compensation profile corresponding to that trimming layer.

[0056] like Figure 4 As shown, the coarse hole contour 71 is located inside the target hole contour 74, and a hole wall allowance 73 to be removed is formed between the coarse hole contour 71 and the target hole contour 74. The compensation scan trajectory 75 is set in the area where the corresponding hole wall allowance 73 is located, and is determined according to the target hole wall contour and the hole wall allowance to be removed at the current trimming layer.

[0057] When the target micro-hole is a straight-walled circular hole and the hole diameter is basically the same at each depth position of the coarse hole, the hole edge compensation contour corresponding to each trimming layer can adopt the same or basically the same contour size.

[0058] When the target micropore has a predetermined taper, the hole edge compensation profile of different sizes can be determined according to the target hole diameter at the corresponding depth of each trimming layer, so that the hole walls at different depths after trimming can jointly form the predetermined taper.

[0059] When the coarse hole itself has a diameter variation along the depth direction, even if the target micro hole is a straight-walled hole, at least two trimming layers can use hole edge compensation contours of different sizes to compensate for the diameter variation or roughing error at different depth positions of the coarse hole.

[0060] The hole edge compensation profile can be determined based on one or more of the following: target hole diameter at the corresponding trimming layer, target hole wall taper, hole wall allowance, measured profile of the coarse hole, effective laser spot size, and kerf compensation amount.

[0061] Specifically, a target hole wall model can be established first based on the design parameters of the target micropore, and the target hole wall contour at the depth position can be determined according to the depth position corresponding to each trimming layer. Then, combined with the actual hole wall position or the estimated hole wall position at the corresponding depth position of the coarse hole, the hole wall allowance to be removed by the trimming layer can be determined, and the hole edge compensation contour executed by the galvanometer scanning component 3 can be generated accordingly.

[0062] After determining the hole edge compensation contour of each trimming layer, the controller 8 controls the Z-axis focusing component 9 to change the depth position of the laser focus, so that the laser focus is positioned at the depth position corresponding to the first trimming layer.

[0063] After the laser focus reaches the depth position corresponding to the first trimming layer, the controller 8 controls the galvanometer scanning assembly 3 to drive the laser spot to perform high-speed scanning along the hole edge compensation contour corresponding to the first trimming layer, thereby removing at least part of the hole wall excess 73 at the first trimming layer.

[0064] When a single scan is insufficient to achieve the required trimming amount, the scan can be repeated multiple times along the corresponding hole edge compensation contour, or multiple scan contours that gradually approach the target hole wall position can be used to scan sequentially to gradually remove the hole wall excess 73 at the corresponding trimming layer.

[0065] After the first trimming layer is trimmed, the controller 8 controls the Z-axis focusing component 9 to change the depth position of the laser focus, so that the laser focus is positioned to the next trimming layer, and then controls the galvanometer scanning component 3 to scan along the hole edge compensation contour corresponding to the next trimming layer.

[0066] The multiple trimming layers are processed sequentially in the manner described above until the reserved hole wall allowance 73 along the hole depth direction of the coarse hole is removed layer by layer, and the hole wall areas after processing of each trimming layer are used to form the target hole wall of the target microhole.

[0067] During the aforementioned layered trimming stage, the galvanometer scanning assembly 3 primarily performs local contour scanning within the remaining hole wall area corresponding to each trimming layer, rather than re-scanning and removing the main material layer by layer throughout the entire cross-section of the target microhole. Therefore, the high scanning speed and low moment of inertia of the galvanometer scanning assembly 3 can be utilized to complete fine trimming of small-area hole walls, while simultaneously reducing the need for the workpiece motion platform 5 to repeatedly perform minute contour movements.

[0068] The compensation scanning trajectory 75 corresponding to each trimming layer can be a single closed contour, a contour group composed of multiple closed contours set radially at intervals, or a spiral scanning trajectory set around the contour of the target hole wall.

[0069] Multiple trimming layers can be processed sequentially from the coarse hole inlet to the coarse hole outlet, or sequentially from the coarse hole outlet to the coarse hole inlet. For example, for a deep micro-hole that has already been penetrated, trimming can be performed gradually from the position near the hole outlet towards the hole inlet, depending on the chip removal conditions, in order to reduce the impact of debris inside the hole on the subsequent trimming area.

[0070] During the layered trimming process, the processing nozzle 42 can deliver protective or auxiliary gas to the processing area to help remove particles and molten material generated during processing. If necessary, a negative pressure suction structure can also be installed on one side or below the workpiece 7 to further remove debris generated during processing.

[0071] Example 4

[0072] This embodiment further employs a detection compensation method to determine or correct the hole edge compensation contour, based on the aforementioned embodiments.

[0073] After the coarse hole is processed, the imaging detection unit of the detection component 10 acquires an image of the coarse hole opening, and the image determines the outline of the coarse hole opening, the center of the coarse hole, and the positional deviation of the center of the coarse hole relative to the galvanometer scanning center 76.

[0074] When a positional deviation is detected between the center of the coarse hole and the preset galvanometer scanning center 76, the controller 8 performs an overall translational correction on the hole edge compensation contour corresponding to each trimming layer according to the positional deviation, so that the subsequent galvanometer scanning trajectory corresponds to the actual coarse hole position.

[0075] For example, when the actual center of the coarse hole has offsets of ΔX and ΔY relative to the theoretical center in the X and Y directions respectively, the original hole edge compensation contours of each trimming layer can be translated according to the corresponding ΔX and ΔY coordinates to correct the positional error between the galvanometer scanning center and the actual center of the coarse hole without having to readjust the clamping position of the workpiece 7.

[0076] When the detection component 10 or other detection device can acquire information on the coarse hole wall features, hole outlet features, hole diameter or coarse hole taper at different depth positions, it can further correct the hole edge compensation profile of the corresponding trimming layer based on the detection results.

[0077] For example, when the test results show that the diameter of the hole at the inlet is smaller than that at the outlet, the amount of hole wall material to be removed at different depths can be determined by combining the target hole wall size. This allows the trimming layer near the hole inlet and the trimming layer near the hole outlet to use different hole edge compensation profiles.

[0078] When the target microhole is a straight-walled hole, the hole diameter after processing at different depths can be made consistent through the above-mentioned layered compensation. When the target microhole is a hole with a predetermined taper, the target hole diameter at the corresponding depth of each trimming layer can be determined according to the predetermined taper, so that the hole walls after processing by multiple trimming layers can jointly form the required tapered profile.

[0079] Therefore, the hole edge compensation profile of each trimming layer can be predetermined based on the design size of the target microhole, or it can be corrected after the rough hole is processed by combining the actual test results of the rough hole, thereby reducing the impact of rough cutting error on the subsequent hole wall finishing accuracy.

[0080] Example 5

[0081] Roughing and layered trimming can be performed using different laser processing parameters.

[0082] The main purpose of roughing is to quickly remove the main material inside the target micropores. Therefore, relatively large single-pulse energy or other laser processing parameters with high material removal efficiency can be used.

[0083] The main purpose of layered trimming is to accurately remove the small amount of hole wall residue 73 left on the hole wall of the coarse hole. Therefore, a single pulse energy lower than that of roughing can be used, and the hole wall residue 73 can be gradually removed by increasing the contour scanning speed and / or increasing the number of scans, so as to reduce the possibility of excessive material removal caused by a single scan.

[0084] In one implementation, the contour scanning speed used in the layer trimming process is higher than the contour movement speed in the roughing stage, thereby leveraging the high-speed, small-range scanning characteristics of the galvanometer scanning component 3.

[0085] After all the trimming layers are processed, the laser focus can be positioned at the edge of the target micro-hole, and the galvanometer scanning assembly 3 can be controlled to perform one or more cleaning scans along the target hole contour 74. The cleaning scan can use laser energy lower than that of the roughing stage to remove residual microburrs, recast material, or local contour protrusions near the hole opening.

[0086] In other embodiments, the roughing motion assembly is not limited to the workpiece motion platform 5. The roughing process can be completed by the workpiece motion platform 5 driving the workpiece 7 to move relative to the laser focus, or it can be completed by the workpiece motion platform 5 and the galvanometer scanning assembly 3 working together, or other motion mechanisms that can cause the laser beam and the workpiece 7 to generate roughing relative motion can be used to complete the removal of the main material.

[0087] Similarly, Z-axis focusing is not limited to being achieved by moving the laser cutting head 4, but can also be achieved by moving the workpiece 7, adjusting the dynamic focusing lens group, or using a combination of the above different focusing methods to change the depth position of the laser focus.

[0088] Through the above processing, the roughing stage mainly completes the rapid removal of the main material inside the target micropore, leaving a wall allowance 73 between the rough hole wall and the target hole wall. After the rough hole processing is completed, multiple trimming layers are set along the depth direction of the rough hole, and the laser focus depth and the corresponding hole edge compensation contour are adjusted for different trimming layers. The galvanometer scanning assembly 3 removes the hole wall allowance 73 layer by layer. In this way, the different depth positions of the deep micropore are respectively located in the corresponding effective laser action area, and layered compensation trimming is implemented for the target hole wall size or rough hole processing error at different depth positions, thereby taking into account both the removal efficiency of the main material of the micropore and the final hole wall processing quality.

[0089] The foregoing description illustrates and describes preferred embodiments of the present invention. As previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept by means of the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A laser micro-hole processing method with galvanometer-assisted layered trimming, characterized in that, Includes the following steps: S1. Determine the target hole wall contour and hole depth of the target micro-hole to be processed; S2. Control the laser beam to generate a rough cutting relative motion with the workpiece, remove the main material inside the target micro-hole to form a coarse hole, and make the hole wall of the coarse hole retain a hole wall margin relative to the target hole wall towards the inside of the hole. S3. After the rough hole is processed, the hole wall of the rough hole is divided into multiple trimming layers along the hole depth direction, and the corresponding hole edge compensation contour is determined according to the target hole wall contour at the corresponding depth of each trimming layer. S4. Adjust the depth position of the laser focus according to the processing order of the multiple trimming layers, so that the laser focus is sequentially positioned to the corresponding trimming layer, and drive the laser spot to scan along the hole edge compensation contour corresponding to the corresponding trimming layer through the galvanometer scanning component, so as to remove the hole wall excess at the corresponding trimming layer layer by layer to form the hole wall of the target microhole.

2. The laser micro-hole processing method with galvanometer-assisted layered trimming according to claim 1, characterized in that, The hole edge compensation profile is determined based on one or more of the following: target hole diameter at the corresponding trimming layer, target hole wall taper, hole wall allowance, measured profile of the coarse hole, effective laser spot size, and kerf compensation amount.

3. The laser micro-hole processing method with galvanometer-assisted layered trimming according to claim 1, characterized in that, At least two of the trimmed layers correspond to hole edge compensation profiles with different profile dimensions to compensate for the diameter variation of the coarse hole along the hole depth direction and / or form a target micropore with a predetermined hole wall taper.

4. The laser micro-hole processing method with galvanometer-assisted layered trimming according to claim 1, characterized in that, The effective laser processing depth ranges corresponding to adjacent trimming layers partially overlap, and the interlayer spacing between the trimming layers is determined based on one or more of the Rayleigh length of the laser focus, the material removal depth, and the taper of the target hole wall.

5. The laser micro-hole processing method with galvanometer-assisted layered trimming according to claim 1, characterized in that, After the rough hole is machined, at least one of the following is obtained: the hole opening profile, the hole wall features, and the hole outlet features; When the orifice contour is obtained, the positional deviation of the coarse hole relative to the scanning center of the galvanometer is determined based on the orifice contour, and the scanning center of the galvanometer scanning assembly is corrected accordingly. When at least one of the hole wall features and hole outlet features is obtained, at least one of the hole diameter and taper of the coarse hole is determined based on the acquisition result, and the hole edge compensation profile of the corresponding trimming layer is corrected accordingly.

6. The laser micro-hole processing method with galvanometer-assisted layered trimming according to claim 1, characterized in that, The single-pulse energy used in the trimming process is lower than that used in the roughing process, and the contour scanning speed of the trimming process is higher than that of the roughing process.

7. A laser micro-hole processing device for galvanometer-assisted layered trimming, characterized in that, Includes a laser source, a galvanometer scanning assembly, a laser cutting head, a Z-axis focusing assembly, a roughing motion assembly, and a controller; The galvanometer scanning assembly is disposed on the light-incident side of the laser cutting head, and the outgoing light path of the galvanometer scanning assembly is connected to the focusing light path of the laser cutting head, so that the laser beam deflected by the galvanometer scanning assembly is focused by the laser cutting head and then incident on the workpiece. The Z-axis focusing component is used to change the depth position of the laser focus relative to the workpiece; The coarse cutting motion assembly is used to generate a coarse cutting relative motion between the laser beam and the workpiece, so as to remove the main material inside the target microhole and form a coarse hole that retains a hole wall allowance relative to the target hole wall. The controller is connected to the laser source, the galvanometer scanning assembly, the Z-axis focusing assembly, and the coarse cutting motion assembly, and is configured to: after the coarse hole is processed, divide the hole wall of the coarse hole into multiple trimming layers along the hole depth direction, and determine the corresponding hole edge compensation contour according to the target hole wall contour at the corresponding depth of each trimming layer; control the Z-axis focusing assembly to position the laser focus sequentially to each trimming layer, and control the galvanometer scanning assembly to drive the laser spot to scan along the corresponding hole edge compensation contour to remove the hole wall excess at the corresponding trimming layer layer by layer.

8. The laser micro-hole processing equipment with galvanometer-assisted layered trimming according to claim 7, characterized in that, The galvanometer scanning assembly is fixedly connected to the laser cutting head, or the galvanometer scanning assembly and the laser cutting head are mounted on a common rigid mounting bracket.

9. The laser micro-hole processing equipment with galvanometer-assisted layered trimming according to claim 7, characterized in that, A beam relay component is provided between the galvanometer scanning component and the focusing component of the laser cutting head. The beam relay component makes the equivalent scanning turning point of the galvanometer scanning component and the entrance pupil surface of the focusing component form a conjugate relationship. The Z-axis focusing assembly includes at least one of the following: a linear module for driving at least one of the laser cutting head and the workpiece to move along the Z-axis; A dynamic focusing lens assembly is installed in the laser optical path.

10. The laser micro-hole processing equipment with galvanometer-assisted layered trimming according to claim 7, characterized in that, It also includes a detection component, which includes an imaging detection unit for acquiring the orifice contour and / or orifice wall features of the coarse orifice. The controller is connected to the detection component and corrects the scanning center of the galvanometer scanning component and / or the orifice edge compensation contour of the corresponding trimming layer based on the detection results of the detection component.

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