An equidistant laser beam splitting device

Abstract

The present invention discloses an equidistant laser beam splitting device, comprising a circular track, which is composed of an inner track and an outer track located in the same plane and arranged concentrically. A rotating mirror module is located at the center of the circular track, and multiple beam splitting light path modules are located on the circular track, with the projection spacing of the multiple beam splitting light path modules in the Y-axis direction of the circular track being consistent. A laser emits a laser beam, which is collimated by a collimator and then enters the rotating mirror module. The rotating mirror module can rotate 360 ​​degrees around the center of the optical axis. The laser beam is emitted by the rotating mirror module, and the emitted laser beam is uniformly irradiated into each beam splitting light path module while rotating. The beam splitting light path module shapes and collimates the laser beam and focuses it onto the surface of the processing sample located on the moving plane. The device includes a collimation, rotating mirror beam splitting, shaping, and focusing module to achieve beam splitting and focusing of the laser beam, and is used for high-precision laser line engraving processing, significantly improving the accuracy and stability of laser etching.

Description

Technical Field

[0001] The present invention relates to the technical field of laser processing, and in particular to an equidistant laser beam splitting device. Background Art

[0002] The laser scribing process involves numerous parameter settings, placing high demands on the efficiency, precision, and flexibility of the laser processing equipment and its core optical path system. Currently, common laser processing equipment is categorized into two types: single-channel laser equipment and multi-channel laser equipment. Single-channel laser equipment relies on a single laser and a simple optical path design. While simple in structure and low in cost, it struggles to meet processing and detection requirements, resulting in low processing efficiency. Currently, laser beam splitting of a single-channel laser output path can be used to achieve parallel processing, thereby improving processing efficiency.

[0003] Laser beam splitting technology, by splitting a laser beam into multiple sub-beams, enables simultaneous execution of multiple workstations or multiple processing processes. Due to its high efficiency, high precision, and flexibility, laser beam splitting technology is widely used in various fields, particularly those requiring high precision and efficiency. It is widely used in electronics, automotive, aerospace, medical devices, precision instruments, 3D printing, packaging, energy and environmental protection, and other fields. It is particularly well-suited for high-precision and high-efficiency production requirements such as multi-hole processing, precision drilling, laser scribing, laser cutting, and surface treatment. Laser beam splitting methods primarily use optical beam splitters, fiber beam splitters, microlens arrays, polarization beam splitters, spatial light modulators (SLMs), and reflective beam splitters. Optical beam splitters split a laser beam into multiple sub-beams through reflection or transmission; fiber beam splitters distribute laser energy to different optical fibers; microlens arrays focus multiple beams using multiple small lenses; polarization beam splitters divide a beam based on its polarization state; spatial light modulators split the beam by dynamically adjusting the phase and intensity of the beam; and reflective beam splitters achieve light separation through reflection at different angles.

[0004] In the scribing process, traditional mechanical scribing and mask etching methods are prone to material waste and uneven loss between layers. Laser etching technology is considered key to improving effective area utilization. For example, the solar cell manufacturing process requires multiple laser etching processes, including P1-P3 laser scribing and P4 edge cleaning. These processes use multiple etching passes to form individual modules, which are then connected in series to form components, ensuring the circuit structure and performance of the battery. Ultrafast laser etching technology, with its non-thermal processing and fine ablation characteristics, can minimize damage to perovskite cells. For laser etching technology, parallel etching with multiple beams can significantly improve etching efficiency. At the same time and etching rate, the etching efficiency of N beams is N times higher than that of a single beam. The multiple beams separated by splitting require equal spacing, the same energy, and a consistent focus spot.

[0005] Patent publication number CN116117332A discloses a "downward-emitting laser optical path system and solar cell marking machine," which uses a polarizing beam splitter to achieve 12-beam splitting. This device is used in solar marking equipment to improve marking efficiency. Patent publication number CN116160134A discloses a "multi-focus laser assembly, laser processing device, and method," which uses a diffraction optical element for light splitting and then adjusts the divergence angle of each beam to achieve multi-focus processing. Patent publication number CN115156698A discloses a "laser beam splitting processing device," which uses a diffraction beam splitter to achieve multi-beam splitting.

[0006] Mechanical beam splitting for multi-beam parallel etching requires numerous components, resulting in complex mechanical equipment and high costs. Mechanical beam splitting employs polarization beamsplitters and half-wave plates to control the energy of each laser beam. Polarization beamsplitters rely on the polarization state of the incident light. If the polarization direction of the beam does not align with the designed beamsplitter orientation, the splitting efficiency is significantly reduced. Furthermore, polarization beamsplitters can cause polarization loss, shifting the polarization state of some beams and affecting subsequent optical operations. Their performance is typically targeted at a specific wavelength range and cannot effectively process optical signals with a wide wavelength, limiting their applicability in certain applications. Multi-beam parallel etching using diffractive optical elements (DOEs) suffers from issues such as uneven spot intensity distribution, limited processing capability for single, repeating structures, and limited processing accuracy. Furthermore, DFOs require precise microstructure design and fabrication, typically employing techniques such as photolithography and electron beam etching, which are both demanding and expensive. Using spatial light modulators for beam splitting, however, can easily damage them due to their low damage threshold. The disadvantages of fiber optic beam splitters include power loss, reduced beam quality, and temperature sensitivity. Due to the insertion loss introduced by the beam splitter, the power of each output channel will be reduced, affecting processing efficiency and quality. The loss in multi-beam splitting is relatively large (1×8, the beam splitting loss is about 9dB). Due to the relatively low damage threshold, fiber optic beam splitters are difficult to achieve high-power laser splitting. At the same time, the beam splitter may cause the beam to diverge or change in shape, reducing processing accuracy. In addition, fiber optic beam splitters are sensitive to temperature changes, and thermal effects may cause performance degradation, limiting their application in high-power and high-precision processing. The stability and maintenance requirements of the fiber optic connection also increase the complexity of the system. Summary of the Invention

[0007] In order to solve the problems existing in the above-mentioned background technology, the present invention provides an equally spaced laser beam splitting device, which includes a collimation, a rotating mirror splitting, a shaping and a focusing module to realize the splitting and focusing of the laser beam, which is used for high-precision laser line engraving processing and greatly improves the accuracy and stability of laser etching.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention provides an equidistant laser beam splitting device, comprising a laser, a collimator, a rotating mirror module, a ring track, a plurality of splitting optical path modules and a moving platform;

[0010] The circular track is composed of an inner track and an outer track that are located in the same plane and are arranged concentrically. The rotating mirror module is located at the center of the circular track. Multiple splitter optical path modules are located on the circular track, and the projection spacing of the multiple splitter optical path modules in the Y-axis direction of the circular track is consistent to ensure the consistency of the laser line spacing. In specific applications, the number and installation position of the splitter optical path modules can be reasonably arranged according to the number of splits and the focal distance. The pulse signal received by each splitter optical path module depends on its line width on the circular track. As long as the line width is the same, it can be ensured that each splitter optical path module receives the pulse laser evenly, ensuring the energy consistency of each focused light spot.

[0011] The laser is a high repetition rate pulse laser or a continuous laser. The laser emits a laser beam, which is collimated by a collimator and then enters the rotating mirror module. The center of the optical axis inside the rotating mirror module is perpendicular to the plane of the circular track. The rotating mirror module can rotate 360 ​​degrees around the center of the optical axis. The laser beam is emitted by the rotating mirror module. While rotating, the emitted laser beam is evenly irradiated in each splitting optical path module to achieve beam splitting.

[0012] The beam splitting optical path module shapes and collimates the laser beam and focuses it onto the surface of the processed sample located on the moving plane. The processed sample is fixedly placed on the surface of the moving platform, and the surface of the processed sample is laser-scribed by moving the moving plane.

[0013] Furthermore, the spectroscopic optical path module includes a spectroscopic tube, a first reflector, a pinhole diaphragm, a first lens and a second lens; the inside of the spectroscopic tube is sequentially installed with a coaxial first reflector, a pinhole diaphragm, a first lens and a second lens from top to bottom, and the first reflector is tilted 45° to convert the horizontally transmitted laser beam emitted by the rotating mirror module into a vertically transmitted laser beam. The vertically transmitted laser beam passes through the light hole of the pinhole diaphragm for shaping, and then enters the second lens for focusing after being collimated by the first lens.

[0014] The specific working principle of the spectroscopic optical path module is as follows: the horizontally transmitted spectroscopic laser beam is converted into a vertically transmitted spectroscopic laser beam through the first reflector. Since the spot size and spot position of the non-collimated incident light will change after focusing, a small aperture diaphragm is set below the first reflector to limit the imaging of incident light with different incident angles. Below the small aperture diaphragm is the first lens, which collimates the spectroscopic laser beam into a collimated beam. The collimated beam is focused on the surface of the processed sample through the second lens below, and the marking on the surface of the processed sample is achieved by the movement of the mobile platform.

[0015] Furthermore, the diameter of the aperture of the pinhole stop is 1 mm to 3 mm, which can ensure that the focused light spot is smaller than 10 μm.

[0016] The present invention utilizes a pinhole diaphragm to limit the angle of incidence of the light beam during rotation. The size of the focused light beam can be controlled by changing the size of the aperture of the pinhole diaphragm. The smaller the aperture of the pinhole diaphragm, the smaller the focused light spot and the higher the marking accuracy. The diameter of the aperture of the pinhole diaphragm determines the offset of the light beam in the splitting light path and also determines the size of the focused light spot. The larger the diameter of the aperture, the greater the diaphragm offset and the larger the focused light spot. Zemax simulation verification shows that controlling the diameter of the aperture to 1mm to 3mm can ensure that the focused light spot is less than 10μm, which can effectively reduce the changes in the size and position of the light spot caused by the offset of the incident light beam and ensure processing accuracy.

[0017] Furthermore, the rotating mirror module includes a rotating mirror barrel, a drive device, a third lens, and a second reflector. The rotating mirror barrel is driven by the drive device and can rotate 360 ​​degrees around the center of the optical axis. The third lens and the second reflector, which are arranged at a 45-degree angle, are fixedly installed in the rotating mirror barrel along the center of the optical axis, from top to bottom. The second reflector is arranged horizontally opposite the first reflector. The laser beam enters the rotating mirror barrel vertically, is focused by the third lens, and is then reflected by the second reflector to emit a horizontally transmitted laser beam backward. The central axis of the rotating mirror barrel coincides with the center of the internal optical axis.

[0018] The specific working principle of the rotating mirror module is as follows:

[0019] By setting up a rotating mirror module, the laser beam enters vertically downward into the rotating mirror barrel, and is emitted horizontally backward from the second reflector and rotates 360° around the center. The outgoing laser beam is irradiated on each splitting optical path module while rotating.

[0020] Furthermore, the pinhole stop is located at the focal position of the third lens.

[0021] A telephoto third lens is placed above the 45° second reflector in the rotating mirror module, and its focal point is located at the position of the small aperture diaphragm in the beam splitting optical path module. The function of the small aperture diaphragm is mainly to limit the imaging of light beams with different divergence angles on the focal plane.

[0022] Furthermore, the rotation speed of the driving motor is 3000 r / min, and the output frequency of each split laser beam is 50 Hz.

[0023] The driving motor can be a frameless torque motor. The speed of the frameless torque motor is 3000r / min, which is equivalent to 50 revolutions per second. The speed of 50 revolutions is much smaller than the laser repetition rate (MHZ, KHZ). Of course, the speed of the frameless torque motor is relatively slow, and the speed can be increased by using the motor and gear speed change, but it is also much smaller than the laser repetition rate, so the divided laser beams can be approximately evenly distributed in space.

[0024] In practical applications, the higher the drive motor speed, the better. However, commercially available frameless torque motors cannot achieve very high speeds; 3000 rpm is already above average. Using gear shifting can increase the speed. The output frequency of a split-beam laser is calculated based on the rotational speed and is independent of the laser's repetition rate. Lasers require high repetition rates or continuous pulses, without requiring precise timing for each pulse to reach each output port. The laser output frequency (Hz) for a single processing port is calculated as motor speed (r / min) / 60.

[0025] Furthermore, a third reflector tilted at 45° is provided between the collimator and the rotating mirror module, and the third reflector converts the horizontal laser beam collimated by the collimator into a vertically transmitted laser beam.

[0026] Furthermore, the central axis of the spectroscopic lens barrel coincides with the center of the internal optical axis.

[0027] Furthermore, the central wavelength of the laser beam emitted by the laser is 532 nm or 1064 nm.

[0028] In the present invention, by adjusting the spacing of optical devices and using reflectors with working wavelengths including 532nm and 1064nm, the optical system is suitable for etching with lasers of 532nm and 1064nm wavelengths. Other splitting methods require different structures to be designed and different optical devices to be used for etching with lasers of 532nm and 1064nm.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention utilizes a high-speed rotating mirror module in conjunction with multiple splitting optical path modules with consistent lateral projection spacing to achieve beam splitting of the laser beam. The parameters of the split multiple laser beams are only related to the parameters of the laser, and there is no need to manually adjust each laser path. At the same time, the optical imaging system is consistent, and the resulting focused light spots are also consistent. That is, the multiple laser beams split by the present invention have consistent spacing, consistent line spacing, and consistent energy.

[0031] (2) Since the spot size and spot position of the non-collimated incident light will change after focusing, the optical path design of the present invention, through a combination of multiple lenses and a small aperture, can limit the imaging of light beams incident at different divergence angles on the focal plane, making the position and size of the focused light spot sufficiently stable;

[0032] (3) The optical splitter is realized only by a driving device, a number of lenses and a number of reflectors, which uses fewer optical devices and reduces the cost. In contrast, the existing technology uses a mechanical optical splitting method, which requires a large number of polarization splitting prisms, adjustable attenuator splitters and reflectors, which is more expensive.

[0033] (4) The optical splitting system of the present invention is suitable for splitting laser beams with central wavelengths of 532nm and 1064nm. It can achieve focusing of laser beams with two wavelengths by simply moving the device position without replacing the device. It is suitable for etching with lasers with wavelengths of 532nm and 1064nm. Other optical splitting methods require different structures to be designed and different optical devices to be used for etching with lasers with wavelengths of 532nm and 1064nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Figure 1 This is a spatial position diagram of the transfer mirror module, the annular track, and the beam splitting optical path module in Example 1;

[0036] Figure 2 This is a structural diagram of the medium-distance laser beam splitting device of Example 1;

[0037] Figure 3 This is the simulation result of a 1mm pinhole diaphragm with a laser beam having a central wavelength of 532nm in Example 1;

[0038] Figure 4 This is the simulation result of a 5mm pinhole diaphragm with a laser beam having a central wavelength of 532nm in Example 2;

[0039] Figure 5 This is the simulation result of the 1mm pinhole diaphragm of the laser beam with a central wavelength of 1064nm in Example 3;

[0040] Among them, the specific drawings are marked as follows:

[0041] Laser 1, collimator 2, third reflector 3, rotating mirror module 4, annular track 5, inner track 6, outer track 7, rotating mirror barrel 8, driving device 9, third lens 10, second reflector 11, spectroscopic optical path module 12, spectroscopic barrel 13, first reflector 14, pinhole diaphragm 15, first lens 16, second lens 17, moving platform 18, processing sample 19. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] Example 1

[0044] This embodiment discloses an equidistant laser beam splitting device, such as Figure 1 and Figure 2 As shown, it includes a laser 1, a collimator 2, a third reflector 3, a rotating mirror module 4, a ring track 5, a plurality of splitting optical path modules 12 and a moving platform 18;

[0045] The circular track 5 consists of an inner track 6 and an outer track 7, which are located in the same plane and are concentrically arranged. The rotating mirror module 4 is located at the center of the circular track 5. Multiple beam splitting optical path modules 12 are located on the circular track 5, and the projection spacing of the multiple beam splitting optical path modules 12 in the Y-axis direction of the circular track 5 is consistent, ensuring consistent spacing between laser lines. In specific applications, the number and installation positions of the beam splitting optical path modules 12 can be reasonably arranged based on the number of beam splits and the focal distance. The pulse signal received by each beam splitting optical path module 12 depends on its line width on the circular track 5. As long as the line width is consistent, each beam splitting optical path module 12 can be guaranteed to receive the pulsed laser evenly, ensuring the energy consistency of each focused light spot.

[0046] The laser 1 emits a laser beam. In this embodiment, the central wavelength of the laser beam emitted by the laser 1 is 532 nm. After being collimated by the collimator 2, the laser beam enters the third reflector 3 set at a 45° angle. The third reflector 3 converts the horizontal laser beam collimated by the collimator 2 into a vertically transmitted laser beam, and the laser beam enters the rotating mirror module 4 vertically downward. The center of the optical axis inside the rotating mirror module 4 is perpendicular to the plane of the annular track 5. The rotating mirror module 4 can rotate 360° around the center of the optical axis. The laser beam is emitted by the rotating mirror module 4. The emitted laser beam is evenly irradiated in each splitting optical path module 12 while rotating, thereby realizing beam splitting.

[0047] The spectroscopic optical path module 12 shapes and collimates the laser beam and focuses it onto the surface of the processing sample 19 located on the moving plane. The processing sample 19 is fixedly placed on the surface of the moving platform 18, and the surface of the processing sample 19 is laser-scribed by moving the moving plane.

[0048] The beam splitter optical path module 12 includes a beam splitter tube 13, a first reflector 14, a pinhole diaphragm 15, a first lens 16, and a second lens 17. The first reflector 14, the pinhole diaphragm 15, the first lens 16, and the second lens 17 are coaxially mounted in sequence from top to bottom within the beam splitter tube 13. The first reflector 14 is tilted 45° to convert the horizontally transmitted laser beam emitted by the rotating mirror module 4 into a vertically transmitted laser beam. The vertically transmitted laser beam passes through the aperture of the pinhole diaphragm 15 for shaping, is collimated by the first lens 16, and then enters the second lens 17 for focusing. The internal axis of the beam splitter tube 13 is consistent with the optical axis.

[0049] The specific working principle of the spectroscopic optical path module 12 is as follows: the horizontally transmitted spectroscopic laser beam is converted into a vertically transmitted spectroscopic laser beam through the first reflector 14. Since the spot size and spot position of the non-collimated incident light will change after focusing, a small aperture diaphragm 15 is set below the first reflector 14 to limit the imaging of incident light with different incident angles, so that the position and size of the focused spot are sufficiently stable. Below the small aperture diaphragm 15 is the first lens 16, which collimates the spectroscopic laser beam into a collimated beam. The collimated beam is focused on the surface of the processing sample 19 through the second lens 17 below, and the marking on the surface of the processing sample 19 is achieved by the movement of the moving platform 18.

[0050] The aperture diameter of the pinhole 15 is between XX mm and XX mm. The diameter of the pinhole 15 determines the deflection of the light beam in the splitting optical path and also determines the size of the focused spot. A larger aperture diameter results in greater aperture deflection and a larger focused spot. Controlling the aperture diameter within the range of XX mm to XX mm effectively minimizes changes in spot size and position caused by incident beam deflection, ensuring machining accuracy. In this embodiment, the aperture diameter of the pinhole 15 is 1 mm.

[0051] The rotating mirror module 4 includes a rotating mirror barrel 8, a drive device 9, a third lens 10, and a second reflector 11. The rotating mirror barrel 8 is driven by the drive device 9 and can rotate 360 ​​degrees around the center of the optical axis. The third lens 10 and the second reflector 11, which is tilted 45 degrees, are fixedly installed in the rotating mirror barrel 8 along the center of the optical axis, from top to bottom. The second reflector 11 is arranged horizontally opposite the first reflector 14. The laser beam enters the rotating mirror barrel 8 vertically, is focused by the third lens 10, and then reflected by the second reflector 11, and then emitted backward as a horizontally transmitted laser beam. The central axis of the rotating mirror barrel 8 coincides with the center of the internal optical axis.

[0052] The specific working principle of the rotating mirror module 4 is as follows:

[0053] By setting up the rotating mirror module 4, the laser beam enters vertically downward into the rotating mirror barrel 8, and is emitted horizontally backward from the second reflector 11 and rotates 360° around the center. The outgoing laser beam is irradiated on each splitting optical path module 12 while rotating.

[0054] The pinhole stop 15 is located at the focal position of the third lens 10. A telephoto third lens 10 is placed above the 45° second reflector 11 in the rotating mirror module 4, with its focal point located at the pinhole stop 15 in the beam splitting optical path module 12. The pinhole stop 15 primarily serves to limit the formation of images on the focal plane from light beams with different divergence angles.

[0055] The drive motor rotates at 3000 rpm, and the output frequency of each split laser beam is 50 Hz. A frameless torque motor can be used as the drive motor. The speed of a frameless torque motor is 3000 rpm, which translates to 50 revolutions per second. This speed is far less than the laser's repetition rate (MHz, KHZ). While frameless torque motors rotate at a relatively slow speed, and can be increased by using motor and gear shifting, the speed is still far less than the laser's repetition rate, allowing the split laser beams to be approximately evenly distributed in space.

[0056] In this embodiment, in the ZEMAX simulation test, the diameter of the laser beam after collimation by collimator 2 was approximately 6 mm. The third lens 10 in the rotating mirror module 4 was an H-K9L plano-convex lens with a curvature radius of 103.36 mm, a focal length of 200 mm, and a thickness of 3.5 mm. The center of the second reflector 11 was located 180 mm below the third lens 10. The vertical distance between the center of the second reflector 11 and the 1 mm diameter aperture 15 was 14 mm. 100 mm below the aperture diaphragm 15 was located a first lens 16 (H-K9L plano-convex lens with a curvature radius of 51.68 mm, a focal length of 100 mm, and a thickness of 3 mm). After passing through first lens 16, the beam was collimated and refocused by second lens 17 (H-K9L plano-convex lens with a curvature radius of 10.34 mm, a focal length of 20 mm, and a thickness of 2.4 mm), with the focal position 18.105 mm behind it.

[0057] Figure 3 (a) is a schematic diagram of the optical path of the laser in this embodiment after it passes through the beam expansion and collimation to reach the rotating mirror module and thereafter. Figure 3 (b) Simulation tests show the spot patterns of a laser beam with a central wavelength of 532 nm with incident angles of 0, 0.05°, 0.1°, and 0.15°. When the incident beam is not offset, the RMS radius of the spot is 2.145 μm. When the incident beam is offset by 0.05°, the RMS radius of the spot is 3.026 μm, and the spot position is offset by 0.032 mm on the focal plane. When the incident beam is offset by 0.1°, the RMS radius of the spot is 4.983 μm, and the spot position is offset by 0.065 mm on the focal plane. When the incident beam is offset by 0.15°, the laser beam is completely blocked by the aperture stop. The simulation results show that limiting the incident beam offset angle to 0.1 degrees results in a spot size of 4.983 μm.

[0058] Example 2

[0059] This embodiment discloses an equidistant laser beam splitting device, which differs from the first embodiment in that: in this embodiment, the diameter of the light-passing hole of the pinhole aperture 15 is 5 mm.

[0060] Figure 4 (a) is a schematic diagram of the optical path of the laser after beam expansion and collimation to the rotating mirror module 4 and thereafter in this embodiment. Figure 4(b) Simulation tests show the spot patterns of a laser beam with a central wavelength of 532 nm with incident angles of 0, 0.15°, 0.5°, and 0.8°. When the incident beam is not offset, the RMS radius of the spot is 2.145 μm. When the incident beam is offset by 0.05°, the RMS radius of the spot is 7.595 μm, and the spot position is offset by 0.097 mm on the focal plane. When the incident beam is offset by 0.5°, the RMS radius of the spot is 18.297 μm, and the spot position is offset by 0.357 mm on the focal plane. When the incident beam is offset by 0.8°, the laser beam is completely blocked by the aperture stop. The simulation results show that limiting the incident beam offset angle to 0.5 degrees results in a spot size of 18.297 μm.

[0061] Example 3

[0062] This embodiment discloses an equally spaced laser beam splitting device, which differs from Example 1 in that: in this embodiment, the central wavelength of the laser beam emitted by the laser 1 is 1064 nm, the vertical distance between the center of the second reflector 11 and the small aperture diaphragm 15 with a diameter of 1 mm is 18.5 mm, and after refocusing by the second lens 17, the focusing position is 18.105 mm behind it.

[0063] Figure 5 (a) is a schematic diagram of the optical path of the laser after beam expansion and collimation to the rotating mirror module 4 and thereafter in this embodiment. Figure 5 (b) Simulation tests show the spot patterns of a laser beam with a central wavelength of 1064 nm with incident angles of 0, 0.05°, 0.1°, and 0.15°. When the incident beam is not offset, the RMS radius of the spot is 1.943 μm. When the incident beam is offset by 0.05°, the RMS radius of the spot is 2.886 μm, and the spot position is offset by 0.034 mm on the focal plane. When the incident beam is offset by 0.1°, the RMS radius of the spot is 4.856 μm, and the spot position is offset by 0.069 mm on the focal plane. When the incident beam is offset by 0.15°, the laser beam is completely blocked by the aperture stop. The simulation results show that limiting the incident beam offset angle to 0.1 degrees results in a spot size of 4.856 μm.

[0064] Depend on Figures 3 to 5 It can be seen from the simulation results that the laser beam splitting device provided by the present invention can minimize the influence of the incident light beam offset on the size and position of the focused spot during the rotation of the rotating mirror module 4 through the aperture, thereby ensuring the processing accuracy.

[0065] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An equidistant laser beam splitting device, characterized in that: It includes a laser, a collimator, a rotating mirror module, a ring track, multiple splitting optical path modules and a moving platform; The annular track is composed of an inner track and an outer track that are located in the same plane and are arranged concentrically. The rotating mirror module is located at the center of the annular track. The multiple light splitting optical path modules are located on the annular track, and the projection spacing of the multiple light splitting optical path modules in the Y-axis direction of the annular track is consistent. The laser emits a laser beam, which is collimated by a collimator and then enters the rotating mirror module. The optical axis center inside the rotating mirror module is perpendicular to the plane of the circular track. The rotating mirror module can rotate 360 ​​degrees around the optical axis center. The laser beam is emitted from the rotating mirror module, and the emitted laser beam is evenly irradiated in each splitting optical path module while rotating. The light splitting optical path module shapes and collimates the laser beam and focuses it onto the processing sample surface located on the moving plane, and laser scribes the processing sample surface by moving the moving plane; The rotating mirror module includes a rotating mirror barrel, a driving device, a third lens, and a second reflector. The rotating mirror barrel is driven by the driving device and can rotate 360 ​​degrees around the center of the optical axis. The third lens and the second reflector arranged at a 45-degree angle are installed in the rotating mirror barrel from top to bottom along the center of the optical axis. The second reflector is arranged horizontally opposite to the first reflector. The laser beam enters the rotating mirror barrel vertically, is focused by the third lens, and is then reflected by the second reflector to emit a horizontally transmitted laser beam backward. The beam splitting optical path module includes a beam splitting tube, a first reflector, a pinhole diaphragm, a first lens, and a second lens. The beam splitting tube is provided with the first reflector, the pinhole diaphragm, the first lens, and the second lens coaxially arranged in sequence from top to bottom. The first reflector is tilted at 45 degrees to convert the horizontally transmitted laser beam emitted by the rotating mirror module into a vertically transmitted laser beam. The vertically transmitted laser beam passes through the light hole of the pinhole diaphragm for shaping, and then is collimated by the first lens before entering the second lens for focusing. The diameter of the light-through hole of the pinhole aperture is 1 mm to 3 mm.

2. The equally spaced laser beam splitting device according to claim 1, characterized in that: The pinhole stop is located at the focal position of the third lens.

3. The equally spaced laser beam splitting device according to claim 1, characterized in that: The rotation speed of the driving device is 3000 r / min, and the output frequency of each split laser beam is 50 Hz.

4. The equally spaced laser beam splitting device according to claim 1, characterized in that: A third reflector tilted at 45° is provided between the collimator and the rotating mirror module. The third reflector converts the horizontal laser beam collimated by the collimator into a vertically transmitted laser beam.

5. The equally spaced laser beam splitting device according to claim 1, characterized in that: The central axis of the spectroscopic lens barrel coincides with the center of the internal optical axis.

6. The equally spaced laser beam splitting device according to claim 1, characterized in that: The central wavelength of the laser beam emitted by the laser is 532nm or 1064nm.

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