Laser Microfabrication System and Method with Controllable Taper

Abstract

The present application discloses a laser micro - machining system and method with controllable taper. The system includes: a variable magnification beam expander system configured to expand the emitted laser beam; a beam displacement module configured to adjust the translation amount of the emitted laser beam; a beam adjustment module configured to modulate the translated laser beam to generate a first - order diffracted light and two - dimensionally adjust the diffraction angle of the first - order diffracted light at a frequency greater than a preset frequency threshold, so that the first - order diffracted light scans in a two - dimensional plane at a speed greater than a first preset speed threshold; an imaging system configured to scale the scanning angle of the first - order diffracted light according to a preset ratio; and a field lens configured to focus the first - order diffracted light to generate a focal spot with a diameter less than a preset diameter threshold, and the focal spot scans the product to be processed at a speed greater than a second preset speed threshold under the action of two - dimensional adjustment. The present application solves the technical problem of uncontrollable machining taper in conventional laser machining systems.

Description

Technical Field

[0001] The present application relates to the field of laser processing, and in particular to a laser micromachining system and method with controllable taper. Background Art

[0002] Laser processing is widely used in various military and civilian fields such as aerospace, medical equipment, semiconductors, 3C, etc. due to its many advantages such as high processing efficiency, no material selectivity, small heat-affected zone during processing, no contact, no stress, and no tool wear, and has gradually developed into one of the mainstream processing methods.

[0003] However, the laser beam with Gaussian intensity distribution output by the laser has problems such as divergence angle and uneven intensity distribution, which leads to a certain taper in the processed microstructure, such as a large microhole entrance and a small exit; a wide front and a narrow back of the slit, etc. Usually, such a taper is called a positive taper. Positive taper processing can meet most laser processing needs. However, in some special application fields, the taper of certain components in some core devices directly affects the performance of the entire device. For example, in the microhole processing of automobile fuel injectors, the inverted tapered hole can maximize the atomization effect of the fuel injection; in the processing of medical ablation catheter tips, it is necessary to improve the cooling efficiency by reducing the processing taper. Based on these processing requirements with different tapers, there is an urgent need to develop a laser precision processing technology with controllable taper.

[0004] A controllable taper laser drilling technology based on four optical wedges has been proposed. This technology utilizes two high-angle optical wedges to translate the incident beam. The taper of the micro-hole being machined is adjusted by varying the spacing between the two high-angle wedges. Two low-angle optical wedges are then combined to deflect the incident beam, causing the focused spot to deviate from the optical axis of the focusing lens. During operation, the four optical wedges rotate synchronously via a servo motor, rotating and scanning the focal spot around the optical axis of the focusing lens while simultaneously providing a microfeed along the optical axis. This ultimately enables the machining of micro-circular holes of varying diameters, tapers, and depths.

[0005] A controllable taper laser drilling technology based on a dove prism has also been proposed. The dove prism is mounted on a high-speed torque motor, and each rotation of the prism produces two rotational scans of the laser. The collimated laser beam undergoes angular deflection and lateral translation at the front end before entering the dove prism. Finally, a focusing lens focuses the laser beam onto the working plane, enabling circular scanning drilling of varying tapers.

[0006] In addition, the existing technology can also use 5D galvanometer to control the laser processing taper, and the motor drives the lens to rotate to control the lateral translation, tilt and feed amount of the light beam, thereby achieving continuous adjustment of the processing taper, depth and size.

[0007] However, in the above laser processing method with controllable taper, the method based on four optical wedges and Dove prisms can only be used for processing micro-circular holes, so its application is greatly limited. The 5D galvanometer has more powerful functions. It can not only be used for micro-circular hole processing, but also for applications such as laser cutting and turning. However, its disadvantages are also extremely obvious: extremely expensive, difficult to operate, and extremely difficult in software development after replacing the product to be processed or changing the processing pattern, etc.

[0008] In view of the above problems, no effective solution has been proposed yet. Summary of the Invention

[0009] The embodiments of the present application provide a laser micro-machining system and method with controllable taper, which at least solve the technical problems of low processing efficiency and uncontrollable processing taper in the conventional laser micro-machining system.

[0010] According to one aspect of the embodiments of the present application, a laser micro-machining system with controllable taper is provided, including: a variable magnification beam expander module configured to expand the laser beam with Gaussian intensity distribution emitted, so that the size of the laser beam matches the laser micro-machining system; a beam displacement module configured to translate the laser beam by adjusting the rotation amount of the beam displacement module; a beam adjustment module configured to modulate the translated laser beam to generate a first-order diffracted light and two-dimensionally adjust the diffraction angle of the first-order diffracted light at a frequency greater than a preset frequency threshold, so that the first-order diffracted light scans in a two-dimensional plane at a speed greater than a first preset speed threshold; an imaging system configured to scale the scanning angle and scanning speed of the first-order diffracted light according to a certain ratio; and a field lens configured to focus the scaled first-order diffracted light to generate a focal spot with a diameter smaller than a preset diameter threshold, wherein, under the action of the two-dimensional adjustment, the focal spot scans the product to be processed at a speed greater than a second preset speed threshold.

[0011] In an exemplary embodiment, the beam displacement module is a parallel crystal or a parallel plate glass. The beam displacement module is placed on a high-precision electric control rotating table, and the control system is used to manipulate the electric control rotating table to flexibly adjust the angle of the beam displacement module relative to the incident beam in the vertical plane (xoz plane), thereby changing the translation amount of the outgoing beam relative to the incident beam. The initial position of the beam displacement module is perpendicular to the incident beam.

[0012] In one example, the beam adjustment module includes the following components arranged in sequence along the optical path: a first acousto-optic deflector, which is orthogonally arranged with respect to the incident direction of the laser beam, and is configured to modulate the translated laser beam to generate the first-order diffracted light, and control the first-order diffracted light to scan in the horizontal direction within the processing surface of the product to be processed; a half-wave plate, which adjusts the polarization direction of the first-order diffracted light output by the first acousto-optic deflector; a second acousto-optic deflector, which is orthogonally arranged with respect to the first acousto-optic deflector, and is configured to control the first-order diffracted light with adjusted polarization direction to scan in the vertical direction within the processing surface.

[0013] In one example, the beam adjustment module is placed on a high-precision electronically controlled displacement stage, which is configured to control the two-dimensional acousto-optic deflector to move upward or downward in the vertical direction (z-axis).

[0014] In one example, the laser micro-machining system further includes an imaging system arranged along the optical path between the beam adjustment module and the field lens, which is configured to scale the scanning angle of the first-order diffracted light according to a preset ratio; the beam adjustment module is further configured to make the first-order diffracted light incident at a position deviating from the object plane of the imaging system and generate a beam tilt after passing through the imaging system by adjusting the feed amount of the beam adjustment module.

[0015] In one example, the imaging system includes the following components arranged in sequence along the optical path: a first focusing lens, the front focal point of the first focusing lens coincides with the position where the first-order diffracted light exits from the beam adjustment module, and the central optical axis of the first focusing lens coincides with the first-order diffracted light of the beam adjustment module driven at the center frequency; a second focusing lens, the front focal plane of the second focusing lens coincides with the rear focal plane of the first focusing lens, the central optical axis of the second focusing lens coincides with the central optical axis of the first focusing lens, the rear focal plane of the second focusing lens coincides with the front focal plane of the field lens, and the central optical axis of the second focusing lens coincides with the central optical axis of the field lens.

[0016] In one example, the initial position of the beam adjustment module is placed on the object plane of the imaging system, and the exit point of the first-order diffracted light from the beam adjustment module coincides with the front focal point of the imaging system.

[0017] In one example, the system further includes a beam termination device, which is arranged at a position on the rear focal plane of the first focusing lens and deviates from the optical axis of the first focusing lens, and is configured to block the unmodulated zero-order light and other unwanted diffracted lights.

[0018] In one example, the system further includes a variable magnification beam expander module arranged in front of the beam displacement module along the optical path, configured to expand the emitted laser beam with a Gaussian intensity distribution by adjusting the beam expansion multiple of the variable magnification beam expander module, so that the size of the laser beam matches the laser micro-machining system.

[0019] In one example, the system further includes a mirror disposed between the variable magnification beam expander module and the beam displacement module along the optical path, configured to change the propagation direction of the expanded laser beam, so that the laser beam enters the beam adjustment module at a preset angle.

[0020] In one example, it further includes a control system configured to perform at least one of the following: driving the beam displacement module to rotate in a vertical plane orthogonal to the processing surface of the product to be processed to adjust the translation amount of the laser beam; driving and adjusting the operating frequency of the beam adjustment module to adjust the deflection angle of the first-order diffracted beam; driving the beam adjustment module to displace upward or downward in the vertical direction; and driving the processing platform carrying the product to be processed to move relative to the focal spot along a predetermined path.

[0021] According to another aspect of the embodiments of the present application, there is also provided a laser micro-machining method with a controllable taper, including: expanding the emitted laser beam with a Gaussian intensity distribution so that the size of the laser beam matches the laser processing system; translating the expanded laser beam by adjusting the rotation amount of the beam displacement module; modulating the translated laser beam to generate a first-order diffracted light, and two-dimensionally adjusting the diffraction angle of the first-order diffracted light at a frequency greater than a preset frequency threshold, so that the first-order diffracted light scans in a two-dimensional plane at a speed greater than a first preset speed threshold; scaling the scanning angle and the scanning speed; focusing the first-order diffracted light to generate a focal spot with a diameter smaller than a preset diameter threshold, wherein the focal spot scans the product to be processed at a speed greater than a second preset speed threshold under the action of the two-dimensional adjustment; and by manipulating the feed amount of the beam adjustment module in the vertical direction (z direction), making the first-order diffracted light incident at a position deviating from the object plane of the imaging system and generating a beam tilt after passing through the imaging system to control the taper of the laser processing.

[0022] In the embodiments of the present application, during the laser processing, by changing the beam expansion multiple of the variable magnification beam expander module to adjust the diameter of the laser beam, using the control system to control the rotation amount of the beam displacement module to adjust the translation amount of the laser beam, and simultaneously controlling the feed amount of the beam adjustment module, the tilt amount of the focal spot is flexibly adjusted, so as to achieve the purpose of controllable taper laser processing, and further solve the technical problems of low processing efficiency and uncontrollable processing taper in the conventional laser micro-machining system. Description of the Drawings

[0023] The drawings described herein are provided to further understand the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0024] Figure 1 is a schematic structural diagram of an optical system for high-efficiency laser processing with controllable taper according to an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of the beam displacement module adjusting the translation amount of the outgoing beam according to an embodiment of the present application;

[0026] Figure 3 is a partially enlarged schematic diagram of the sequential scanning and random scanning trajectories of the laser spot according to an embodiment of the present application;

[0027] Figure 4 is a schematic diagram of the beam deflection of the acousto-optic deflector according to an embodiment of the present application;

[0028] Figure 5 is a schematic diagram of the two-dimensional acousto-optic deflector regulating the two-dimensional scanning of the focal spot under different input ultrasonic frequencies according to an embodiment of the present application;

[0029] Figure 6 is a schematic diagram of the beam propagation of the first-order diffracted light with a diameter of D incident from the front focal plane of the imaging system according to an embodiment of the present application;

[0030] Figure 7 is a schematic diagram of the beam propagation of the central ray l′ of the first-order diffracted light with a diameter of D after translation passing through the imaging system 6 and the field lens 8 according to an embodiment of the present application.

[0031] Figure 8 is a schematic diagram of the focus tilt situation and the processing taper obtained by the beam adjustment module taking different feed amounts in the vertical direction (z direction) according to an embodiment of the present application;

[0032] Figure 9 is a curve graph (a) of the functional relationship between the rotation angle γ of the beam displacement module and the feed amount Δz of the beam adjustment module, and the relationship between the feed amount Δz, the scanning angle α and the tilt amount of the focal spot (b, c, d) according to an embodiment of the present application;

[0033] Figure 10 is a schematic structural diagram of an optical system of a high-efficiency and high-quality laser micro-hole processing system with controllable taper according to an embodiment of the present application;

[0034] Figure 11 is a flowchart of a high-efficiency laser processing method with controllable taper according to an embodiment of the present application. Detailed implementation manners

[0035] To enable those skilled in the art to better understand the solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are only some of the embodiments of this application, rather than all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above accompanying drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0037] Embodiment 1

[0038] According to an embodiment of this application, a high-efficiency laser processing system with controllable taper is provided. This processing system is mainly used to control the taper of laser processing and improve the efficiency of laser processing.

[0039] Figure 1 is a schematic structural diagram of a high-efficiency laser processing system with controllable taper according to an embodiment of this application. As Figure 1 shown, this system includes a laser 1, a variable magnification beam expander module 2, a reflector 3, a beam displacement module 4, a beam adjustment module 5, an imaging system 6, a beam termination device 7, a field lens 8, a processing platform 10, and a control system 11 arranged in sequence along the optical path.

[0040] The beam displacement module 4 is placed on a high-precision electrically controlled rotary table; the beam adjustment module 5 is placed on a high-precision electrically controlled displacement table; the beam adjustment module 5 is a two-dimensional acousto-optic deflector, including: a first acousto-optic deflector 51, a half-wave plate 52, and a second acousto-optic deflector 53; the imaging system includes: a first focusing lens 61 and a second focusing lens 62. The product to be processed 9 is placed on the processing platform 10.

[0041] 1. Laser

[0042] The laser 1 is used to emit a laser beam with an initial Gaussian intensity distribution. In one example, the wavelength of the laser beam emitted by the laser 1 is in the range of 200 nm to 1100 nm, the diameter is less than 5 mm, and the polarization state is linearly polarized.

[0043] 2. Beam displacement module

[0044] The beam displacement module 4 is used to adjust the translation amount of the laser beam. In one embodiment, the beam displacement module 4 is a parallel crystal or a parallel plate glass. The beam displacement module 4 is placed on a high-precision electronically controlled rotating stage, and the angle of the beam displacement module 4 relative to the incident beam in the vertical plane (xoz plane) is flexibly adjusted through the electronically controlled rotating stage, thereby changing the translation amount d of the outgoing beam relative to the incident beam. Among them, the initial position of the beam displacement module 4 is perpendicular to the incident beam, that is, d = 0 mm.

[0045] As Figure 2 shown, after the beam displacement module 4 is accurately controlled by the electronically controlled rotating stage to rotate clockwise by an angle γ relative to the incident laser beam l0 to reach the R4 position, the laser beam is refracted inside the beam displacement module 4. According to the refractive index formula, we can get:

[0046] sinγ = nsin i

[0047] where n is the refractive index of the beam displacement module 4, and i is the refraction angle. After the laser beam undergoes two refractions and exits from the rear surface of the beam displacement module 4, the outgoing beam l' has a certain translation relative to the incident beam l, and the translation amount d is:

[0048]

[0049] where L represents the thickness of the beam displacement module 4 along the beam propagation direction.

[0050] In order to make the translated beam l' enter the beam adjustment module 5 again at the same position and the same angle, it is necessary to displace the beam adjustment module 5 upward to the S5 position, as Figure 2 shown, the displacement amount Δz is:

[0051]

[0052] where δ represents the incident angle of the beam adjustment module 5.

[0053] 3. Beam adjustment module

[0054] The beam adjustment module 5 is used to modulate the translated laser beam to generate the first-order diffracted light, the non-modulated zero-order light, and other unwanted diffracted lights, and two-dimensionally adjust the diffraction angle of the first-order diffracted light at a frequency greater than a preset frequency threshold.

[0055] In one embodiment, the beam adjustment module 5 is composed of a two-dimensional acousto-optic deflector and a high-precision electrically controlled displacement stage. The two-dimensional acousto-optic deflector is placed on the high-precision electrically controlled displacement stage, and the two-dimensional acousto-optic deflector is controlled to move up or down in the vertical direction (z-axis) by the electrically controlled displacement stage, and the displacement amount is Δz.

[0056] In one embodiment, the two-dimensional acousto-optic deflector is composed of a first acousto-optic deflector 51, a half-wave plate 52 and a second acousto-optic deflector 53, and is used for ultra-fast two-dimensional adjustment of the first-order diffracted light to scan at high speed in a two-dimensional plane. The first acousto-optic deflector 51 and the second acousto-optic deflector 53 are placed orthogonally, and the half-wave plate 52 is placed between the first acousto-optic deflector 51 and the second acousto-optic deflector 53.

[0057] The first acousto-optic deflector 51 is used to adjust the scanning of its first-order diffracted light in the vertical plane (xoz plane), the half-wave plate 52 is used to adjust the polarization direction of the first-order diffracted light, and the second acousto-optic deflector 53 is used to adjust the scanning of its first-order diffracted light in the front-back direction (yoz plane).

[0058] In one example, the acousto-optic crystals of the first acousto-optic deflector 51 and the second acousto-optic deflector 53 are fused silica glass, sapphire or tellurium dioxide crystal (related to the working wavelength), the working wavelengths are all in the range of 200nm to 1100nm, the working frequencies are between 30MHz and 500MHz, the frequency resolution is greater than or equal to 1kHz, the frequency refresh interval is less than 1μs, and the window size is less than 10mm. With such a structure, the two-dimensional acousto-optic deflector can control the beam to scan at a frequency exceeding 1MHz, while the scanning frequency of the galvanometer is usually only dozens of kilohertz. Therefore, in this embodiment, the efficiency of laser micromachining using the beam adjustment module based on the two-dimensional acousto-optic deflector is much greater than the processing efficiency of the galvanometer + field lens mode in conventional laser processing equipment.

[0059] In the two-dimensional acousto-optic deflector, the scanning methods of the first acousto-optic deflector 51 and the second acousto-optic deflector 53 are sequential scanning and random scanning in one-dimensional direction. The scanning method of the two-dimensional acousto-optic deflector is sequential scanning and random scanning in a two-dimensional plane, as Figure 3 shown, where the solid black arrow line represents the scanning trajectory of the laser spot. Figure 3 (a) in is a schematic diagram of sequential scanning of the laser spot according to an embodiment of the present application, and (b) is a partially enlarged schematic diagram of the random scanning trajectory. In this way, the two-dimensional acousto-optic deflector can support random processing operations of the laser spot at any point on the product to be processed, which can greatly improve the flexibility of laser micromachining.

[0060] Figure 4This figure shows a schematic diagram of the operation of the acousto-optic deflector provided in an embodiment of the present application. The acousto-optic deflector is a beam scanning device based on the acousto-optic effect. An ultrasonic drive signal is input into the acousto-optic transducer to generate vibrations, which generate ultrasonic waves in the acousto-optic crystal. Under the influence of the ultrasonic waves, a periodic refractive index distribution is generated within the acousto-optic crystal, forming a Bragg diffraction grating.

[0061] In this embodiment, when the laser is incident at a specific angle δ, Bragg diffraction occurs. At this time, the angle between the first-order diffracted light at the center frequency and the optical axis (MN) is α, that is, the scanning angle, as shown in FIG. Figure 2 Then, by changing the ultrasonic frequency to change the grating constant, the diffraction angle of the first-order diffraction light is changed, thereby achieving one-dimensional scanning of the light beam. The angular scanning range is related to the bandwidth of the operating frequency.

[0062] It is important to note that the AOD frequency refresh interval is extremely short, typically less than 1 μs, which means it can be used for ultra-high-frequency beam scanning. Furthermore, because the AOD's ultrasonic drive signal can be randomly switched within its bandwidth, the AOD's first-order diffracted light can achieve both sequential and random angular scanning within its scanning angle range.

[0063] In this embodiment, two sets of acousto-optic deflectors are placed in orthogonal series and controlled in linkage, so that high-speed sequential scanning or random scanning of the first-order diffraction light beam can be achieved in a two-dimensional plane perpendicular to the optical axis. The optical axis here is defined as the optical axis of the first-order diffraction light at the center operating frequency of the two-dimensional acousto-optic deflector.

[0064] Figure 5 The schematic diagram of the two-dimensional acousto-optic deflector controlling the two-dimensional scanning of the focused light spot in the plane is shown, where f L 、f C 、f H The low-frequency, center-frequency, and high-frequency ultrasonic signals corresponding to the drivers of the acousto-optic deflectors are respectively provided. By providing different ultrasonic signals to two orthogonally placed one-dimensional acousto-optic deflectors, that is, inputting different drive frequency combinations to the first acousto-optic deflector 51 and the second acousto-optic deflector 53, it is possible to control the first-order diffracted beam to perform two-dimensional ultrafast scanning in the xoy plane.

[0065] The positions of the first acousto-optic deflector 51 and the second acousto-optic deflector 53 can be interchanged. The interchange of the positions of the first acousto-optic deflector 51 and the second acousto-optic deflector 53 does not affect the two-dimensional adjustment effect of the two-dimensional acousto-optic deflector on the first-order diffraction light. However, it is necessary to add a half-wave plate before the two-dimensional acousto-optic deflector. The half-wave plate is used to adjust the polarization direction of the laser after translation to meet the polarization requirements of the two-dimensional acousto-optic deflector for the incident light.

[0066] In addition to the first-order diffracted light, the light generated by modulating the translated laser beam with the two-dimensional acousto-optic deflector also includes the unmodulated zero-order light and other unwanted diffracted lights. These zero-order lights and other unwanted diffracted lights are blocked by the beam termination device 7 to avoid damaging the device and accidentally injuring the operator.

[0067] In the embodiment of the present application, an acousto-optic deflector is introduced, which can not only perform two-dimensional scanning of the light beam at an extremely high speed, but also avoid the mechanical vibration and acceleration / deceleration problems of conventional scanning instruments (such as galvanometers). The optical path system is more stable. Therefore, using the laser micro-machining system of the embodiment of the present application can not only greatly improve the efficiency and flexibility of laser micro-machining, but also effectively ensure the quality of laser micro-machining.

[0068] 4. Imaging system

[0069] The imaging system is used to scale the scanning angle and scanning speed of the first-order diffracted light according to a certain ratio. The scaled first-order diffracted light beam can be used for laser processing after being focused by the field lens (8). The maximum processing area and scanning speed per single time of laser processing are also scaled.

[0070] In an exemplary embodiment, the imaging system 6 includes: a first focusing lens 61 and a second focusing lens 62. Their positions are as follows: the front focus of the first focusing lens 61 coincides with the position where the first-order diffracted light exits from the two-dimensional acousto-optic deflector 5; the central optical axis of the first focusing lens 61 coincides with the first-order diffracted light of the two-dimensional acousto-optic deflector driven at the central frequency; the rear focal plane of the first focusing lens 61 coincides with the front focal plane of the second focusing lens 62; the rear focal plane of the second focusing lens 62 coincides with the front focal plane of the field lens 8; the central optical axes of the first focusing lens 61, the second focusing lens 62, and the field lens 8 coincide and are parallel to the z-axis.

[0071] In an exemplary embodiment, the imaging system 6 magnifies the scanning angle (or scanning speed) of the first-order diffracted light according to a certain ratio. After the magnified first-order diffracted light beam is focused by the field lens 8, the maximum processing area (or scanning speed) of the focal spot is also magnified. The magnification ratio is related to the ratio of the focal length of the first focusing lens 61 to the focal length of the second focusing lens 62.

[0072] Figure 6 It is a schematic diagram of the beam propagation of the first-order diffracted light with a diameter of D according to the embodiment of the present application, which is incident from the front focal plane of the imaging system and is focused by the field lens. After the central ray l of the first-order diffracted light beam passes through the imaging system 6, it exits at an angle β with the optical axis MN and is obliquely incident on the field lens 8; after the obliquely incident ray is refracted by the field lens 8, the exit ray finally irradiates on the product to be processed and the angle with the optical axis MN is θ. The distance r from the optical axis MN can be described as:

[0073] f1tanα = f2tanβ

[0074]

[0075] Then the scanning angle of the first-order diffracted light after passing through the imaging system 6 changes to:

[0076]

[0077] Therefore, when the focal length f1 of the first focusing lens in the imaging system 6 is greater than the focal length f2 of the first focusing lens, i.e., f1 > f2, the scanning angle of the first-order diffracted light after passing through the imaging system 6 is magnified, which means that the scanning speed of the first-order diffracted light beam is magnified proportionally, thus helping to improve the laser scanning processing speed; in addition, the increase in the scanning angle will also cause the position where the focus acts on the product to be processed to deviate outward relative to the optical axis MN, that is, under the same conditions, the introduction of the imaging system 6 can effectively expand the laser processing area. Therefore, when processing products of the same size, the introduction of the imaging system 6 can reduce the number of movements of the processing platform, thereby greatly improving the laser processing efficiency.

[0078] Since in practical applications, laser beams all have a certain diameter, it is inaccurate to describe the entire laser beam only by the transmission effect of the central ray l passing through the optical system. Therefore, next, the situation of the first-order diffracted light with a diameter of D passing through the imaging system 6 and the field lens 8 is analyzed. As Figure 6 shown, since the two side rays l1 and the rightmost ray l2 in the vertical plane (xoz plane) have an offset of D / 2 relative to the central ray l, after the rays l1 and l2 pass through the imaging system 6 and the field lens 8 in sequence, there are angles Δθ1 and Δθ2 with respect to the central ray l, and Δθ1 = -Δθ2. From the trigonometric function relationship, we can obtain:

[0079]

[0080] s From this, we can obtain:

[0081]

[0082] Therefore, the inner tilt angle θ in and the outer tilt angle θ out of the edge rays l1 and l2 on both sides of the first-order diffracted light with a diameter of D in the xoz plane after passing through the imaging system and the field lens for laser processing are respectively:

[0083]

[0084]

[0085] Wherein, θ represents the angle between the outgoing light ray of the central light ray l after passing through the imaging system and the field lens in sequence and the vertical direction (z-axis). The inner tilt amount and the outer tilt amount are respectively defined as the tilt amounts on the side of the processed structure close to the optical axis MN and the side far from the optical axis MN. When the first-order diffracted light with a diameter of D is incident from the object plane of the imaging system (the front focal plane of the first focusing lens 61), and the central light ray l of the light beam passes through the front focus of the first focusing lens 61, θ = 0, θ out =-θ in >0, that is, in the actual laser processing process, due to the light beam having a certain diameter D, therefore, the laser processing method of the conventional galvanometer and field lens combination will inevitably have a taper, and the taper cannot be adjusted.

[0086] 5. Field lens

[0087] The field lens 8 is used to focus the first-order diffracted light to generate an extremely small focal spot. Specifically, the focal spot is scanned and processed on the product to be processed 9 at a high speed at a speed greater than the second preset speed threshold under the two-dimensional adjustment of the light beam displacement module 4 and the light beam adjustment module 5, wherein the product to be processed 9 is placed on the processing platform 10.

[0088] In one example, the light beam displacement module 4 is rotated by an angle γ to cause the laser beam to be translated by d, and at the same time the light beam adjustment module 5 is fed by Δz in the z direction. Then the schematic diagram of the light beam propagation of the central light ray l' of the first-order diffracted light with a diameter of D passing through the imaging system 6 and the field lens 8 is as Figure 7 shown. According to the law of refraction of light, it can be obtained that:

[0089]

[0090] r' = r

[0091] Wherein, θ' and r' are respectively the angle between the refracted light ray and the optical axis MN and the distance after the central light ray l' of the first-order diffracted light with a diameter of D passes through the imaging system 6 and the field lens 8. From this, it can be obtained that:

[0092]

[0093]

[0094] Then the inner tilt amount θ' of the laser processing after the central light ray l' of the first-order diffracted light with a diameter of D passes through the imaging system 6 and the field lens 8 in and the outer tilt amount θ' out and the relationship between the feed amount Δz of the light beam adjustment module 5 in the z direction is:

[0095]

[0096]

[0097] The following conclusions can be obtained from the above formula:

[0098] (1) When Δz|sinα| > D / 2, θ′ out > θ′ in > 0. The controllable taper laser micro - machining system and method provided by the embodiments of the present application can be used to machine micro - structures with a small reverse taper on the inner wall and a large positive taper on the outer wall, such as Figure 8 (a) as shown;

[0099] (2) When Δz|sinα| = D / 2, θ′ out > θ′ in = 0. The controllable taper laser micro - machining system and method provided by the embodiments of the present application can be used to machine micro - structures with no taper on the inner wall and a positive taper on the outer wall, such as Figure 8 (b) as shown;

[0100] (3) When 0 < Δz|sinα| < D / 2, θ′ out > 0 > θ′ in > -θ′ out . The controllable taper laser micro - machining system and method provided by the embodiments of the present application can be used to machine micro - structures with a small positive taper on the inner wall and a large positive taper on the outer wall, such as Figure 8 (c) as shown;

[0101] (4) When Δz|sinα| = 0, θ′ out = -θ′ in > 0. The controllable taper laser micro - machining system and method provided by the embodiments of the present application can be used to machine micro - structures with a positive taper on the inner wall and a positive taper on the outer wall, and the absolute values of the tapers are the same, such as Figure 8 (d) as shown;

[0102] (5) When -D / 2 < Δz|sinα| < 0, θ′ out > 0 > -θ′ out > θ′ in . The controllable taper laser micro - machining system and method provided by the embodiments of the present application can be used to machine micro - structures with a large positive taper on the inner wall and a small positive taper on the outer wall, such as Figure 8 (e) as shown;

[0103] (6) When Δz|sinα| = -D / 2, θ′ out = 0 > θ′ in . The controllable taper laser micro - machining system and method provided by the embodiments of the present application can be used to machine micro - structures with a large positive taper on the inner wall and no taper on the outer wall, such as Figure 8 (f) as shown;

[0104] (7) When Δz|sinα| < -D / 2, θ' in < θ' out < 0. For the controllable taper laser micro - machining system and method provided by the embodiments of the present application, it can be used to machine micro - structures with a large positive taper on the inner wall and a small negative taper on the outer wall, such as Figure 8 shown in (g);

[0105] (8) For the controllable taper laser micro - machining system and method provided by the embodiments of the present application, the diameter D of the first - order diffracted light directly affects the taper size of the inner wall and the outer wall of the laser - machined structure.

[0106] Through the above analysis, it can be seen that for the controllable taper laser micro - machining system and method provided by the embodiments of the present application, the beam diameter D can be changed by the variable magnification beam expander module, the rotation γ angle of the beam displacement module 4 can be flexibly changed by the control system to adjust the translation amount d of the laser beam, and at the same time, the beam adjustment module 5 is fed in the z - direction by Δz to achieve the purpose of flexibly controlling the machining taper.

[0107] According to another aspect of the embodiments of the present application, a high - efficiency laser machining method with controllable taper is also provided, including: expanding the laser beam with a Gaussian intensity distribution emitted by the variable magnification beam expander module 2 so that the size of the laser beam matches the laser machining system; after passing through the beam displacement module 4, the expanded laser beam undergoes translation, and after passing through the beam adjustment module 5, the first - order diffracted light is generated, and the diffraction angle of the first - order diffracted light is two - dimensionally adjusted at a frequency higher than a preset frequency threshold so that the first - order diffracted light scans in a two - dimensional plane at a speed higher than a first preset speed threshold; after the two - dimensional scanned first - order diffracted light passes through the imaging system 6, the scanning angle and the scanning speed are scaled according to a certain ratio; after the scaled laser beam passes through the field lens for focusing, the maximum machining area size (or the laser scanning speed is also scaled by a certain ratio).

[0108] In an example, the maximum incident light aperture of the field lens 8 is greater than or equal to 10 mm, the focal length is less than 300 mm, and the machining area is less than 200 mm×200 mm. When the size of the product to be machined is larger than the machining area of the field lens 8, it is necessary to move the machining platform 10 for sub - figure stitching.

[0109] Next, the operation process of the high - efficiency laser machining system with controllable taper provided by this embodiment will be described.

[0110] The laser 1 emits a laser beam with a Gaussian intensity distribution, which is expanded by the zoom beam expander module 2 so that the size of the laser beam matches the laser processing system; the expanded laser beam changes direction after passing through the mirror 3; the laser beam with the changed direction is translated after passing through the beam displacement module 4, and the translated laser beam passes through the beam adjustment module 5 to generate a first-order diffracted light, and the diffraction angle of the first-order diffracted light is two-dimensionally adjusted at a frequency greater than a preset frequency threshold, so that the first-order diffracted light scans in the two-dimensional plane at a speed greater than a first preset speed threshold; the first-order diffracted light of the two-dimensional scan passes through the imaging system 6, and the scan angle (or scan speed) is magnified by a certain ratio; the magnified laser beam is focused by the field lens 8 and irradiated on the workpiece 9 placed on the processing platform 10.

[0111] In one example, the following parameters are taken for simulation calculation: the diameter of the expanded beam is D = 3 mm, the thickness of the beam displacement module 4 is L = 150 mm, and the refractive index is n = 1.37; the incident angle of the beam adjustment module 5 is δ = 44 mrad, and the scan angle of the first-order diffracted light is α = -22 mrad to 22 mrad; the focal length of the first focusing lens of the imaging system 6 is f1 = 100 mm, and the focal length of the second focusing lens is f2 = 300 mm; the focal length of the field lens 8 is f3 = 50 mm. Figure 9 (a) shows a curve graph of the function relationship between the rotation angle γ of the beam displacement module 4 and the feed amount Δz of the beam adjustment module 5 in the z direction. Figure 9 (b, c, d) show the relationship between the feed amount Δz of the beam adjustment module 5 in the z direction, the scan angle α of the first-order diffracted light, and the inner tilt amount θ', in the central tilt amount θ', and the outer tilt amount θ'. out It can be found that when the feed amount Δz and the scan angle α take different values, the inner tilt amount θ', in the central tilt amount θ', and the outer tilt amount θ' out are continuously adjustable in the ranges of -9.1° to 2.3°, -5.7° to 5.7°, and -2.3° to 9.1° respectively. This means that the use of the focal spots with different tilt amounts for laser processing can achieve flexible control of the processing taper.

[0112] The controllable taper high-efficiency laser processing system proposed in the embodiment of the present application has the following beneficial effects:

[0113] 1) By adjusting the rotation amount of the beam displacement module, the feed amount of the beam adjustment module, and the beam expansion ratio, the tilt amount of the focal spot is flexibly changed, and then the flexible adjustment of the laser processing taper is realized, solving the problem of uncontrollable processing taper in the conventional processing system;

[0114] 2) Utilize the advantages of no mechanical vibration and no mechanical inertia during the beam scanning process regulated by the two-dimensional acousto-optic deflector to effectively ensure the quality of laser micromachining;

[0115] 3) Utilize the advantages of sequential scanning and random scanning of the two-dimensional acousto-optic deflector to greatly improve the flexibility of laser micromachining;

[0116] 4) Utilize the advantage that the scanning frequency of the two-dimensional acousto-optic deflector far exceeds that of the galvanometer for laser scanning machining to greatly improve the efficiency of laser micromachining; meanwhile, with the help of the imaging system, the processing area is magnified by a certain ratio to reduce the number of platform movements, thereby greatly improving the laser machining efficiency again. Thus, a high-efficiency laser machining system with a controllable taper is realized, which can better meet the requirements of different laser machining, and has very important application value and broad market prospects.

[0117] Embodiment 2

[0118] According to the embodiment of the present application, an optical system for high-efficiency laser machining with a controllable taper is provided. This optical system is mainly used to control the taper of laser machining and improve the efficiency of laser machining.

[0119] As Figure 10 shown, the system includes a laser 1, a variable magnification beam expander module 2, a reflector 3, a beam displacement module 4, a beam adjustment module 5, a beam termination device 7, a field lens 8, a processing platform 10, and a control system 11 arranged in sequence along the optical path.

[0120] The beam displacement module 4 is placed on a high-precision electronically controlled rotary table; the beam adjustment module 5 is placed on a high-precision electronically controlled displacement table; the beam adjustment module 5 is a two-dimensional acousto-optic deflector, including: a first acousto-optic deflector 51, a half-wave plate 52, and a second acousto-optic deflector 53. The product to be processed 9 is placed on the processing platform 10.

[0121] The laser 1 is used to emit a laser beam with an initial Gaussian intensity distribution. In one example, the wavelength of the laser beam emitted by the laser 1 is in the range of 200 nm to 1100 nm, the diameter is less than 5 mm, and the polarization state is linear polarization.

[0122] The beam displacement module 4 is used to adjust the translation amount of the laser beam. In one embodiment, the beam displacement module 4 is a parallel crystal or a parallel plate glass. The beam displacement module 4 is placed on a high-precision electronically controlled rotary table, and the angle of the beam displacement module 4 relative to the incident beam in the vertical plane (xoz plane) is flexibly adjusted through the electronically controlled rotary table, thereby changing the translation amount d of the outgoing beam relative to the incident beam. It should be noted that the initial position of the beam displacement module 4 is perpendicular to the incident beam.

[0123] The beam adjustment module 5 is used to modulate the translated laser beam to generate the first-order diffracted light, the non-modulated zero-order light, and other unnecessary diffracted lights, and two-dimensionally adjust the diffraction angle of the first-order diffracted light at a frequency greater than a preset frequency threshold. In one embodiment, the beam adjustment module 5 is composed of a two-dimensional acousto-optic deflector and a high-precision electronically controlled displacement stage. The two-dimensional acousto-optic deflector is placed on the high-precision electronically controlled displacement stage, and the two-dimensional acousto-optic deflector is controlled to move up and down in the vertical direction (z-axis) by the electronically controlled displacement stage, and the displacement amount is Δz.

[0124] In one embodiment, the two-dimensional acousto-optic deflector is composed of a first acousto-optic deflector 51, a half-wave plate 52, and a second acousto-optic deflector 53, and is used for ultra-fast two-dimensional adjustment of high-speed scanning of its first-order diffracted light in a two-dimensional plane. The first acousto-optic deflector 51 and the second acousto-optic deflector 53 are orthogonally placed, and the half-wave plate 52 is placed between the first acousto-optic deflector 51 and the second acousto-optic deflector 53. The first acousto-optic deflector 51 is used to adjust the scanning of its first-order diffracted light in the vertical plane (xoz plane), the half-wave plate 52 is used to adjust the polarization direction of the first-order diffracted light, and the second acousto-optic deflector 53 is used to adjust the scanning of its first-order diffracted light in the front-rear direction (yoz plane).

[0125] In one example, the acousto-optic crystals of the first light deflector 51 and the second acousto-optic deflector 53 are fused silica glass, sapphire, or tellurium dioxide crystal (related to the working wavelength), the working wavelengths are all in the range of 200 nm to 1100 nm, the working frequencies are between 30 MHz and 500 MHz, the frequency resolution is greater than or equal to 1 kHz, the frequency refresh interval is less than 1 μs, and the window size is less than 10 mm. With such a structure, the two-dimensional acousto-optic deflector can control the beam to scan at a frequency exceeding 1 MHz, while the scanning frequency of the galvanometer is usually only dozens of kilohertz. Therefore, in this embodiment, the efficiency of laser micromachining using the beam adjustment module based on the two-dimensional acousto-optic deflector is much greater than that of the galvanometer.

[0126] The field lens 8 is used to focus the first-order diffracted light to generate an extremely small focal spot.

[0127] The specific operation process of the system in this embodiment is as follows:

[0128] The initial Gaussian beam emitted by the laser 1 is expanded by the zoom beam expander module 2, and the direction of the expanded laser beam is changed after passing through the mirror 3; the laser beam with the changed direction is translated after passing through the beam displacement module 4, and the translated laser beam passes through the beam adjustment module 5 to generate a first-order diffracted light, and the diffraction angle of the first-order diffracted light is two-dimensionally adjusted at a frequency greater than a preset frequency threshold, so that the first-order diffracted light scans in the two-dimensional plane at a speed greater than a first preset speed threshold; the first-order diffracted light with two-dimensional scanning is focused by the field lens 8 and then irradiated on the workpiece 9 placed on the processing platform 10.

[0129] In this embodiment, by adjusting the beam expansion ratio, the rotation amount of the beam displacement module, and the feed amount of the beam adjustment module, the tilt amount of the focal spot is flexibly changed, and then the taper of the laser processing is flexibly adjusted. Then, the diffraction angle of the first-order diffracted light is two-dimensionally adjusted at an ultra-high frequency by the two-dimensional acousto-optic deflector, so that the focal spot scans at a high speed in the processing plane. Since the diffraction angle of the two-dimensional acousto-optic deflector is usually only dozens of milliradians, this method can be used for ultra-high-speed scanning drilling of micro-holes on the scale of dozens of micrometers; in addition, due to the advantages of no mechanical vibration and no mechanical inertia during the beam scanning process controlled by the two-dimensional acousto-optic deflector, the quality of the laser micro-hole scanning processing is effectively guaranteed, thereby realizing a high-efficiency and high-quality laser micro-hole processing method with controllable taper, and then solving the technical problems of uncontrollable processing taper and poor processing quality in the conventional laser micro-hole processing system.

[0130] Embodiment 3

[0131] According to an embodiment of the present application, a laser micro-machining method with controllable taper is provided, as Figure 11 shown, the method includes:

[0132] Step S1101, the beam expander system expands the laser beam with Gaussian intensity distribution emitted by the laser, so that the diameter of the laser beam matches the subsequent optical elements;

[0133] Step S1102, after the expanded laser beam passes through the beam displacement module, the transmitted beam is translated relative to the incident beam;

[0134] Step S1103, the translated laser beam passes through the beam adjustment module to generate a first-order diffracted light, and the diffraction angle of the first-order diffracted light is two-dimensionally adjusted at a frequency greater than a preset frequency threshold, so that the first-order diffracted light scans in the two-dimensional plane at a speed greater than a first preset speed threshold;

[0135] Step S1104, after the first-order diffracted light with two-dimensional scanning passes through the imaging system, the scanning angle (or scanning speed) is scaled by a certain ratio;

[0136] In step S1105, the scaled laser beam is irradiated onto the product to be processed placed on the processing platform after being focused by the field lens;

[0137] In step S1106, the taper of laser processing is flexibly adjusted by adjusting the rotation amount of the beam displacement module, the feed amount of the beam adjustment module, and the beam expansion multiple.

[0138] In the embodiment of the present application, the beam displacement module adjusts the translation amount d of the transmitted laser beam. By adjusting the feed amount Δz of the beam adjustment module in the vertical direction (z-direction), the first-order diffracted light is incident at a position deviating from the object plane of the imaging system and passes through the imaging system to generate beam tilt; after the tilted beam is focused by the field lens, the focal spot is no longer perpendicular to the product to be processed, resulting in a certain taper (θ′ out and θ′ in ) in the processed structure. By adjusting the beam expansion multiple, the rotation amount γ of the beam displacement module, and the feed amount Δz of the beam adjustment module, the tilt amount of the focal spot can be flexibly changed, thereby realizing flexible adjustment of the taper of laser processing. The imaging system magnifies the processing area (or increases the laser scanning speed) according to a certain ratio, thereby greatly improving the laser processing efficiency. Thus, high-efficiency laser processing with controllable taper is achieved.

[0139] In the embodiment of the present application, by adjusting the rotation amount of the beam displacement module, the feed amount of the beam adjustment module, and the beam expansion multiple, the tilt amount of the focal spot is flexibly changed, thereby realizing flexible adjustment of the taper of laser processing; the imaging system magnifies the processing area (or increases the laser scanning speed) according to a certain ratio, thereby greatly improving the laser processing efficiency. Thus, a high-efficiency laser processing method with controllable taper is achieved.

[0140] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the embodiments of the present application are not limited by the described action sequences, because according to the embodiments of the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the embodiments of the present application.

[0141] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the embodiments of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present application.

[0142] The serial numbers of the above embodiments of the present application are only for description and do not represent the superiority or inferiority of the embodiments.

[0143] If the integrated unit in the above embodiments is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in the above computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing one or more computer devices (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.

[0144] In the above embodiments of the present application, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0145] In the several embodiments provided by the present application, it should be understood that the disclosed client can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of units or modules can be in an electrical or other form.

[0146] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0147] In addition, in each embodiment of the present application, each functional unit can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0148] The above are only the preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A laser micro-machining system with controllable taper, characterized in that, Including those arranged in sequence along the optical path: A variable magnification beam expander module (2), configured to expand the laser beam with a Gaussian intensity distribution emitted, so that the size of the laser beam matches the laser micro-machining system; A beam displacement module (4), configured to translate the laser beam by adjusting the rotation amount of the beam displacement module (4); A beam adjustment module (5), configured to modulate the translated laser beam to generate first-order diffracted light, and two-dimensionally adjust the diffraction angle of the first-order diffracted light at a frequency greater than a preset frequency threshold, so that the first-order diffracted light scans in a two-dimensional plane at a speed greater than a first preset speed threshold; An imaging system (6), configured to scale the scanning angle of the first-order diffracted light according to a preset ratio; A field lens (8), configured to focus the scaled first-order diffracted light to generate a focal spot with a diameter smaller than a preset diameter threshold, wherein the focal spot scans the product to be processed at a speed greater than a second preset speed threshold under the action of the two-dimensional adjustment; The beam adjustment module (5) includes those arranged in sequence along the optical path: A first acousto-optic deflector (51), arranged orthogonally to the incident direction of the laser beam, configured to modulate the translated laser beam to generate the first-order diffracted light, and control the first-order diffracted light to scan in the horizontal direction of the processing surface of the product to be processed; A half-wave plate (52), adjusting the polarization direction of the first-order diffracted light output by the first acousto-optic deflector (51); A second acousto-optic deflector (53), arranged orthogonally to the first acousto-optic deflector (51), configured to control the first-order diffracted light with adjusted polarization direction to scan in the vertical direction within the processing surface; The beam adjustment module (5) is further configured to, by adjusting the feed amount of the beam adjustment module (5), make the first-order diffracted light incident at a position deviating from the object plane of the imaging system (6) and generate a beam tilt after passing through the imaging system (6).

2. The laser micromachining system according to claim 1, characterized in that: The imaging system (6) includes those arranged in sequence along the optical path: A first focusing lens (61), the front focal point of the first focusing lens (61) coincides with the position where the first-order diffracted light of the beam adjustment module (5) exits the beam adjustment module (5) under the drive of the center frequency, and the central optical axis of the first focusing lens (61) coincides with the first-order diffracted light of the beam adjustment module (5) under the drive of the center frequency; A second focusing lens (62), the front focal plane of the second focusing lens (62) coincides with the rear focal plane of the first focusing lens (61), the central optical axis of the second focusing lens (62) coincides with the central optical axis of the first focusing lens (61), the rear focal plane of the second focusing lens (62) coincides with the front focal plane of the field lens (8), and the central optical axis of the second focusing lens (62) coincides with the central optical axis of the field lens (8).

3. The laser micromachining system according to claim 1, wherein: The initial position of the beam adjustment module (5) is placed at the object plane of the imaging system (6), and the emergence point of the first-order diffracted light of the beam adjustment module (5) coincides with the front focal point of the imaging system (6).

4. The laser micromachining system according to claim 2, wherein: It further includes a beam termination device (7), which is arranged at the rear focal plane of the first focusing lens and at a position deviating from the optical axis of the first focusing lens, and is configured to block the unmodulated zero-order light and other unwanted diffracted lights.

5. The laser micro-machining system according to claim 1, characterized in that, It further includes: A mirror (3), which is arranged along the optical path between the zoom beam expander module (2) and the beam displacement module (4), and is configured to change the propagation direction of the expanded laser beam, so that the laser beam enters the beam adjustment module (5) at a preset angle.

6. The laser micro-machining system according to any one of claims 1 to 5, characterized in that It further includes a control system (11), which is configured to perform at least one of the following: Drive the beam displacement module (4) to rotate in a vertical plane orthogonal to the processing surface of the product to be processed to adjust the translation amount of the laser beam; Drive and adjust the operating frequency of the beam adjustment module (5) to adjust the two-dimensional deflection angle of the first-order diffracted light beam; Drive the beam adjustment module (5) to move upward or downward in the vertical direction; and Drive the processing platform (10) carrying the product to be processed to move relative to the focal spot along a predetermined path.

7. A laser micromachining method using the laser micromachining system according to any one of claims 1-5, characterized in that, It includes: Expand the emitted laser beam with a Gaussian intensity distribution so that the size of the laser beam matches the laser processing system; Translate the laser beam by adjusting the rotation amount of the beam displacement module; Modulate the translated laser beam to generate first-order diffracted light, and two-dimensionally adjust the diffraction angle of the first-order diffracted light at a frequency greater than a preset frequency threshold, so that the first-order diffracted light scans in a two-dimensional plane at a speed greater than a first preset speed threshold; Focus the first-order diffracted light to generate a focal spot with a diameter smaller than a preset diameter threshold, wherein the focal spot scans the product to be processed at a speed greater than a second preset speed threshold under the action of the two-dimensional adjustment.

8. The laser micromachining method according to claim 7, wherein: The method further includes: adjusting the diameter of the laser beam by changing the beam expansion ratio of the zoom beam expander module of the controllable taper laser microprocessing system, controlling the rotation amount of the beam displacement module of the controllable taper laser microprocessing system to adjust the translation amount of the laser beam, and at the same time controlling the feed amount of the beam adjustment module of the controllable taper laser microprocessing system to adjust the tilt amount of the focal spot.

Images