Multi-path laser scribing processing system and solar cell processing equipment

Abstract

The invention discloses a multi-path laser scribing processing system and solar cell processing equipment, an L-shaped adjustable spectroscope (a polarization beam splitter and double half-wave plates) is adopted, the polarization state is regulated and controlled by rotating the half-wave plates, the splitting ratio is continuously adjustable, the light beam incident position of an octahedral beam splitter is adjusted in combination with a small displacement table reflector, and the light splitting ratio is adjusted. Dynamic control over the distance between two light beams is achieved, different scribed line distance requirements are met, a front / back beam splitting etching device is symmetrically arranged, through the design of staggered light paths and superposition of a plurality of vertical plates, double-face synchronous etching and smaller-distance machining are supported, the machining consistency and precision are improved, an octahedral beam splitter is optimized, and the machining efficiency is improved. High-precision light splitting of a parallel emergent light path is ensured, key assemblies such as an L-shaped spectroscope and a displacement table reflector are highly integrated, the number of optical elements is reduced, the size of an optical system is remarkably reduced, the device is suitable for industrial-grade precision machining equipment, and the occupied space and cost of the equipment are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cell processing, and particularly to a multi-channel laser scribing processing system and a solar cell processing device. Background Art

[0002] With the development of photovoltaic technology, laser scribing, as a key process in the production of solar cells, has become one of the research hotspots and plays an important role in the preparation of solar cells. This process selectively removes materials through a high-energy laser beam to achieve non-contact processing, and its accuracy directly determines the size of the "dead zone" of the battery module - that is, the non-power generation area from the outermost side of the P1 line to the outermost side of the P3 line. Research shows that for every 10 μm reduction in the dead zone width, the effective power generation area of the battery can be increased by 0.5 - 1.2%, significantly affecting the photoelectric conversion efficiency and the life of the module. Therefore, modern laser scribing systems need to compress the line width to less than 50 μm on the premise of ensuring no overlap of the P1 / P2 / P3 lines, which poses sub-micron-level requirements for beam control accuracy. In addition, the interval between adjacent batteries is generally between 5 mm and 10 mm, which also poses higher requirements for the beam splitting of the scribing equipment.

[0003] Common laser processing techniques are mainly divided into two types: single-channel laser etching and multi-channel laser etching. The single-channel laser etching system relies on a single laser and a simple optical path design. Although it has a simple structure and low cost, it is difficult to meet the requirements of processing and detection, and the processing efficiency is low. The multi-channel beam splitting processing system realizes the reconstruction of laser energy through a diffractive optical element (DOE) or a spatial light modulator (SLM). The DOE scheme uses a micro-nano structure to decompose a single laser beam into multiple parallel beams with uniform energy distribution (fluctuation < 5%), and ensures that the focal points are synchronized within ±1 μm through dynamic focal spot compensation technology. The SLM-based scheme is more flexible and can adjust the number of split beams (4 - 64 channels) and spatial arrangement in real time through phase encoding, which is particularly suitable for customized processing of batteries.

[0004] However, the existing multi-channel beam splitting processing systems have the following defects:

[0005] 1. For multi-beam parallel etching using mechanical beam splitting, a large number of devices are used, the mechanical structure of the equipment is complex, and the cost is high. When using mechanical beam splitting, a polarization beam splitter and a half-wave plate are used to regulate the energy of each laser beam. When constructing a beam splitting array using a polarization beam splitter and a wave plate (such as the patent solution of CN116117332A), the single-stage beam splitting efficiency loss is about 15%, and in this patent solution, a variety of beam splitting elements are used, so the overall laser power damage must be large.

[0006] 2. The method of using a diffractive optical element for beam splitting is adopted for multi-beam parallel etching. There are problems with the multi-beams split by the diffractive optical element, such as uneven spot intensity distribution, the ability to process only a single repetitive structure, limited processing accuracy, wavelength sensitivity, etc. At the same time, the diffractive optical element requires precise microstructure design and manufacturing, usually using technologies such as photolithography and electron beam etching. These technologies have high requirements for equipment and high costs.

[0007] 3. Using a spatial light modulator for beam splitting, since the damage threshold of the spatial light modulator is small, the laser can easily damage the spatial light modulator.

[0008] In view of the current solution of a beam splitting system composed of multiple polarization beam splitters and reflectors, the present invention optimizes the overall optical structure, constructs a dynamic energy coupling component including an L-shaped adjustable attenuator, realizes fine adjustment of the splitting intensity, can reduce the number of devices, and reduce energy loss. Summary of the Invention

[0009] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a multi-channel laser scribing processing system and a solar cell processing device, which can not only realize multi-optical path processing, but also realize continuous adjustment of the split beam intensity, the spacing of the processing optical paths is adjustable, can meet the requirements of battery scribing with various scribing spacings, reduce the number of devices, and reduce energy loss.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] In the first aspect of the present invention, a multi-channel laser scribing processing system is provided, including a beam splitting prism, a vertical plate, a front beam splitting and etching device, a first reflector and a back beam splitting and etching device;

[0012] The beam splitting ratio of the beam splitting prism is 50:50, which is used to evenly divide a single beam of laser into two output beams. One output beam directly enters the front beam splitting and etching device vertically downward, and the other output beam is turned by the first reflector and then vertically downward into the back beam splitting and etching device. The front beam splitting and etching device and the back beam splitting and etching device have the same structure;

[0013] The front beam splitting and etching device includes two L-shaped adjustable beam splitters with the same structure, a second reflector, a third reflector, an octahedron beam splitter and a focusing lens array;

[0014] The two L-shaped adjustable beam splitters and the second reflector are sequentially arranged on the optical path of the output beam from top to bottom. The L-shaped adjustable beam splitter is used to regulate the polarization state of the input beam, and then split the beam into two orthogonally polarized beams, which are respectively transmitted and reflected to form transmitted light and reflected light. The transmitted light vertically enters the L-shaped adjustable beam splitter or the second reflector directly below. The reflected light in the L-shaped adjustable beam splitter and the reflected light reflected by the second reflector are respectively input horizontally backward into the corresponding third reflector after polarization state regulation. The reflected light after being reflected by the third reflector vertically enters the upper vertical plane a of the corresponding octahedral beam splitter respectively. The beam entering the octahedral beam splitter is split into transmitted light and reflected light by the upper vertical plane b of the octahedral beam splitter. Its reflected light and transmitted light are respectively emitted from the two lower vertical planes c and d of the octahedral beam splitter. The two emitted laser beams are then focused onto the scribed sample surface by the corresponding lenses in the focusing lens array.

[0015] Further improvement lies in that the L-shaped adjustable beam splitter consists of a polarization beam splitter inclined at 45° and two half-wave plates respectively located at the light inlet and the light outlet. The half-wave plate at the light inlet can rotate the angle to regulate the polarization direction of the input linearly polarized laser. Then, the polarization beam splitter decomposes the output beam into two orthogonally polarized beams, and transmits and reflects the two orthogonally polarized beams respectively to form vertically downward transmitted light and horizontal reflected light, and can realize continuous adjustment of the splitting ratio of these two beams of light. Among them, the horizontal reflected light is regulated again by the half-wave plate at the light outlet for the polarization direction of its linearly polarized light. The function of the second half-wave plate is to regulate the splitting ratio of the octahedral beam splitter.

[0016] In the present invention, continuous adjustment of the split light intensity is achieved through the L-shaped adjustable attenuator beam splitter (polarization beam splitter + double half-wave plates). The specific principle is as follows:

[0017] The laser input into the L-shaped adjustable beam splitter is linearly polarized light. The first device in the L-shaped adjustable beam splitter is a half-wave plate (λ / 2 wave plate), which regulates the polarization state of the linearly polarized light by introducing a phase difference of π. When the linearly polarized light is incident on the first half-wave plate, its polarization direction changes with the rotation of the fast axis of the wave plate, and the rotation angle is twice the rotation angle of the wave plate. The second device of the L-shaped adjustable beam splitter is a polarization beam splitter set at a 45° tilt. The principle of the polarization beam splitter is based on birefringence characteristics (s-polarization reflection / p-polarization transmission) or polarization-selective reflection, which decomposes the incident light into two orthogonally polarized lights (such as s-light and p-light). When unpolarized light or mixed polarized light is incident, the device separates the light with different polarization directions through the optical anisotropy of the material or a specific coating, causing refraction or reflection. For example, the s-light is reflected and the p-light is transmitted, thus achieving the beam splitting of the polarization state. Therefore, by adjusting the L-shaped adjustable beam splitter, the rotation angle θ of the first half-wave plate can precisely control the polarization state of the L-shaped beam splitting, thereby controlling the splitting ratio of the transmitted light and the reflected light. In addition, the reflected light passes through a second half-wave plate, and the function of this half-wave plate is to precisely control the polarization state of the reflected light to control the splitting ratio of the octahedral beam splitter. When incident on the dielectric film of the octahedral beam splitter, the linearly polarized light can be decomposed into the synthesis of p-light and s-light, and the adjustment of the linearly polarized direction can control the synthesis ratio of the decomposed p-light and s-light.

[0018] A further improvement lies in that the reflected light reflected by the second mirror is regulated in its polarization state by a half-wave plate arranged at the rear.

[0019] In the present invention, two L-shaped adjustable beam splitters are arranged in the vertical optical path transmission direction, and a second mirror is arranged at the bottom to reflect the transmitted light emitted by the second L-shaped adjustable beam splitter, and then the polarization state of the light beam is precisely regulated by a half-wave plate arranged at the rear to control the splitting ratio of the octahedral beam splitter into which the subsequent light beam enters.

[0020] In specific applications, the number of L-shaped adjustable beam splitters can be adjusted.

[0021] A further improvement lies in that the vertical plane b surface of the octahedral beam splitter located above is composed of multiple layers of film materials, and each layer of film material includes a high-refractive-index film layer and a low-refractive-index film layer arranged in sequence.

[0022] Specifically, the high-refractive-index film layer is made of zirconia material, and the low-refractive-index film layer is made of silica material.

[0023] The design of the high refractive index film layer and the low refractive index film layer must meet the requirements for low laser absorption and maintain stable performance within the target wavelength range. Preferably, the thickness of the high refractive index film layer and the high transmittance film is λ / 4 or an integer multiple thereof, where λ is the wavelength of the laser; the number of film layers of the high refractive index film layer and the low refractive index film layer is 10 to 30. The refractive index difference can increase the reflectivity; the design and regulation of the multilayer film is to regulate the overall reflectivity and refractive index, so that the splitting ratio can be controlled when the polarization changes. It should be noted that the light split by the octahedron is not s-light and p-light, but linearly polarized light with uncertain polarization direction. The energy intensity of the two beams of light separated by the octahedron beam splitter is the same.

[0024] In the present invention, the octahedral beam splitter is optimized and designed. Specifically, an octahedral beam splitter made of a specific coating material (such as zirconium dioxide / silicon dioxide) is used to achieve high-precision beam splitting based on the Fresnel law, and a parallel output light path is ensured by optimizing the geometric structure (such as a cube cutting design).

[0025] A further improvement is that the third reflector is controlled by a displacement drive device to move horizontally, so as to adjust the position of the reflected light entering the a surface of the octahedral beam splitter, and further adjust the distance between the two laser beams emitted from the c and d surfaces of the octahedral beam splitter.

[0026] The present invention adopts a small translation stage reflector system, and the displacement drive device controls the third reflector to move horizontally, dynamically adjusts the incident position of the light beam on the a surface of the octahedral beam splitter, and realizes flexible control of the spacing between the two laser beams emitted from the c and d surfaces of the octahedral beam splitter to meet the requirements of different line spacing.

[0027] A further improvement is that the vertical plate is driven by an X-axis moving platform and can move along the X-axis direction; the focusing lens array is driven by a Z-axis moving platform and can move along the Z-axis.

[0028] The vertical plate is fixed on the X-axis mobile platform, and the incident laser is always collimated and horizontally irradiated. The multi-channel laser scribing processing system can achieve fixed-interval scribing on the surface of the scribing sample. The focusing lens array is fixed on the Z-axis mobile platform, and the focusing lens array is controlled to move up and down by the Z-axis mobile platform to achieve the focusing of the split beam laser.

[0029] A further improvement is that the multiple laser beams derived from the front beam splitting etching device and the multiple laser beams derived from the back beam splitting etching device are arranged alternately.

[0030] In the present invention, the front / back split etching device adopts a symmetric design, realizes double-sided synchronous etching through an interleaved optical path layout, and can also realize scribing with a small pitch, ensuring processing consistency. In specific applications, the scribing pitch can be further reduced by stacking multiple vertical plates to achieve scribing with a smaller pitch and improve processing accuracy.

[0031] In the second aspect of the present invention, there is provided a solar cell processing device, including the above multi-path laser scribing processing system.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) Through dynamic beam splitting regulation, symmetric optical path architecture and optimization of the octahedral beam splitter, the present invention solves the problems of high cost, large energy loss and insufficient flexibility in multi-path optical systems, and significantly improves the efficiency, accuracy and economy of laser scribing of solar cells.

[0034] (2) Dynamic beam splitting regulation mechanism: An L-shaped adjustable beam splitter (polarizing beam splitter + double half-wave plates) is adopted. By rotating the angle of the half-wave plate, the polarization state is precisely regulated to achieve continuous adjustment of the beam splitting ratio and reduce energy loss. Combined with a small displacement stage mirror system, the incident position of the beam on the octahedral beam splitter is dynamically adjusted to flexibly control the distance between the two beams emitted by the octahedral beam splitter, meeting different scribing pitch requirements.

[0035] (3) Symmetric interleaved optical path architecture: The front / back split etching device adopts a symmetric design, realizes double-sided synchronous etching through an interleaved optical path layout, and can also realize scribing with a small pitch, ensuring processing consistency. In specific applications, the scribing pitch can be further reduced by stacking multiple vertical plates to achieve scribing with a smaller pitch and improve processing accuracy. And the symmetric optical path design ensures the synchronism of double-sided etching. Combined with the sub-micron spot control ability of the octahedral beam splitter, the dead zone width can be reduced and the effective power generation area of the battery can be increased.

[0036] (4) Optimized design of the octahedral beam splitter: The octahedral beam splitter using a specific coating material (such as zirconia / silica) realizes high-precision beam splitting based on Fresnel's law, and ensures parallel outgoing optical paths through geometric structure optimization (such as cube cutting design).

[0037] (5) System integration and miniaturization: Key components such as the L-shaped beam splitter and displacement stage mirror are highly integrated, reducing the number of optical elements (such as avoiding multi-stage polarizing beam splitters), significantly reducing the volume of the optical system, being applicable to industrial-grade precision processing equipment, and reducing the space occupied by the equipment and costs. Description of the Drawings

[0038] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0039] Figure 1 It is a schematic diagram of the overall structure of the multi-channel laser scribing processing system in the present invention;

[0040] Figure 2 It is a schematic diagram of the laser processing operation on the scribing sample in the present invention;

[0041] Figure 3 It is a schematic diagram of the structure at the backside beam splitting and etching device in the present invention;

[0042] Figure 4 It is a specific structural diagram of the octahedral beam splitter in the present invention;

[0043] Figure 5 It is a diagram of the layered structure of the b surface of the octahedral beam splitter in the present invention;

[0044] Figure 6 It is the relationship between the polarization change of the incident light and the reflectivity and transmittance of the b surface of the octahedral beam splitter in the present invention;

[0045] Among them, the specific reference numerals are:

[0046] Beam splitting prism 1, vertical plate 2, X-axis moving platform 3, front beam splitting and etching device 4, L-shaped adjustable beam splitter 401, polarization beam splitter 402, half-wave plate 403, second mirror 404, third mirror 405, displacement driving device 406, octahedral beam splitter 407, focusing lens array 408, Z-axis moving platform 5, first mirror 6, back beam splitting and etching device 7, scribing sample 8. Specific embodiments

[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0048] This embodiment provides a multi-channel laser scribing processing system, as Figures 1 to 3 shown, including a beam splitting prism 1, a vertical plate 2, a front beam splitting and etching device 4, a first mirror 6, and a back beam splitting and etching device 7;

[0049] The beam splitting ratio of the beam splitting prism 1 is 50:50, which is used to evenly divide a single beam of laser into two output beams. One output beam directly enters the front beam splitting and etching device 4 vertically downward, and the other output beam is turned by the first mirror 6 and then vertically downward introduced into the back beam splitting and etching device 7. The front beam splitting and etching device 4 and the back beam splitting and etching device 7 have the same structure;

[0050] The front beam splitting and etching device 4 includes two L-shaped adjustable beam splitters 401, a second reflector 404, a third reflector 405, an octahedral beam splitter 407, and a focusing lens array 408 with the same structure;

[0051] The two L-shaped adjustable beam splitters 401 and the second reflector 404 are sequentially arranged on the optical path of the output beam from top to bottom. The L-shaped adjustable beam splitter 401 is used to regulate the polarization state of the input beam, and then divides the beam into two orthogonally polarized beams, which are respectively transmitted and reflected to form transmitted light and reflected light. The transmitted light vertically enters the L-shaped adjustable beam splitter 401 or the second reflector 404 located directly below. The reflected light in the L-shaped adjustable beam splitter 401 and the reflected light reflected by the second reflector 404 are respectively input horizontally backward into the corresponding third reflector 405 after polarization state regulation. The reflected light reflected by the third reflector 405 vertically enters the upper vertical surface a of the corresponding octahedral beam splitter 407 respectively. The beam entering the octahedral beam splitter 407 is divided into transmitted light and reflected light by the upper vertical surface b of the octahedral beam splitter 407. The reflected light and the transmitted light are respectively emitted from the two lower vertical surfaces c and d of the octahedral beam splitter 407. The two emitted laser beams are then focused onto the surface of the scribed sample 8 through the corresponding lenses in the focusing lens array 408.

[0052] Among them, the L-shaped adjustable beam splitter 401 is composed of a polarization beam splitter 402 inclined at 45° and two half-wave plates 403 respectively located at the light inlet and the light outlet. The half-wave plate 403 located at the light inlet can rotate the angle to regulate the polarization state of the input beam. Then, the output beam is decomposed into two orthogonally polarized beams by the polarization beam splitter 402, and the two orthogonally polarized beams are respectively transmitted and reflected to form vertically downward transmitted light and horizontal reflected light. The horizontal reflected light has its polarization state regulated by the half-wave plate 403 located at the light outlet.

[0053] In the present invention, a continuous adjustment of the split light intensity is achieved through an L-shaped adjustable attenuator beam splitter (polarizing beam splitter 402 + double half-wave plate 403). The specific principle is as follows: The laser input to the L-shaped adjustable beam splitter 401 is linearly polarized light. The first device in the L-shaped adjustable beam splitter 401 is a half-wave plate 403 (λ / 2 wave plate), which controls the polarization state of the linearly polarized light by introducing a phase difference of π. When the linearly polarized light is incident on the first half-wave plate 403, its polarization direction changes with the rotation of the fast axis of the wave plate, and the rotation angle is twice the rotation angle of the wave plate. The second device of the L-shaped adjustable beam splitter 401 is a polarizing beam splitter 402 arranged at an angle of 45°. The principle of the polarizing beam splitter 402 is based on birefringence characteristics (s-polarized reflection / p-polarized transmission) or polarization-selective reflection, which decomposes the incident light into two orthogonally polarized lights (such as s-light and p-light). When unpolarized light or mixed polarized light is incident, the device separates the light with different polarization directions through the optical anisotropy of the material or a specific coating, causing refraction or reflection. For example, s-light is reflected and p-light is transmitted, thus achieving the splitting of the polarization state. Therefore, by adjusting the L-shaped adjustable beam splitter 401, the rotation angle θ of the first half-wave plate 403 can achieve precise control of the polarization state of the L-shaped split beam, thereby achieving control of the splitting ratio of the transmitted light and the reflected light. In addition, the reflected light passes through the second half-wave plate 403, and the function of this half-wave plate 403 is to precisely control the polarization state of the reflected light to control the splitting ratio of the octahedral beam splitter 407.

[0054] The principle of the first polarizing beam splitter 402 is as follows:

[0055] The polarizing beam splitter 402 is based on the incident at Brewster's angle. Therefore, the polarization beam splitting dielectric film needs to be glued in the middle of a prism with a high refractive index, and the light enters the beam splitting film layer from the prism medium to meet the condition of total polarization at Brewster's angle. In addition to the polarizing beam splitter 402, there is also a flat beam splitter that enters from the air to the beam splitting dielectric film. The flat beam splitter is also based on the principle of refraction and reflection, but does not produce a polarization effect through Brewster's angle.

[0056] The polarizing beam splitter 402 can achieve total polarization only at a specific incident angle. However, in practical applications, the incident angle will have a certain degree of fluctuation, or it is a divergent / convergent light beam that is not completely collimated. Therefore, it is necessary to understand the characteristics of the polarizing beam splitter 402 under the condition of incident angle fluctuation. When the incident angle at the film interface deviates from Brewster's angle, there is still an s-light component in the reflected light, and its amplitude reflection coefficient does not change much, but a p-light component is also generated in the reflected light. Therefore, the extinction ratio of the reflected light will decrease rapidly, while the transmitted light still maintains a high degree of polarization. However, since a part of the p-light is reflected, the light intensity of the transmitted light will decrease accordingly. It can be seen that the polarization beam splitting characteristics of the polarizing beam splitter 402 are very sensitive to the incident angle.

[0057] Among them, the reflected light reflected by the second reflector 404 is subjected to polarization state regulation by a half-wave plate 403 arranged at the rear. In the present invention, two L-shaped adjustable beam splitters 401 are arranged in the vertical optical path transmission direction, and a second reflector 404 is arranged at the bottom to reflect the transmitted light emitted by the second L-shaped adjustable beam splitter 401, and then the polarization state of the light beam is precisely regulated by a half-wave plate 403 arranged at the rear, so as to control the splitting ratio of the octahedral beam splitter 407 into which the subsequent light beam enters. In specific applications, the number of L-shaped adjustable beam splitters 401 can be adjusted.

[0058] Among them, as Figure 4 and Figure 5 shown, the octahedral beam splitter 407 is obtained by cutting two symmetrical corners from a cube beam splitter. The vertical plane b surface of the octahedral beam splitter 407 located above is composed of multiple layers of film materials, and each layer of film material includes a high refractive index film layer and a low refractive index film layer arranged in sequence. Specifically, the high refractive index film layer is made of zirconia material, and the low refractive index film layer is made of silica material. The design of the high refractive index film layer and the low refractive index film layer needs to meet specific transmittance and reflectivity requirements and maintain stable performance within the target wavelength range. Preferably, the thickness of the high refractive index film layer and the high transmittance film is λ / 4 or an integer multiple thereof, where λ is the wavelength of the laser; the number of film layers of the high refractive index film layer and the high transmittance film is 10 to 30 layers.

[0059] In the present invention, the octahedral beam splitter 407 is optimized. Specifically, the octahedral beam splitter 407 using specific coating materials (such as zirconia / silica) achieves high-precision beam splitting based on Fresnel's law, and ensures parallel output optical paths through geometric structure optimization (such as cube cutting design). In a specific embodiment, the reflected light output by the third reflector 405 is incident on the a surface of the octahedral beam splitter 407 at θ1 = 45°. The material of the octahedral beam splitter 407 is a transparent glass material. Taking the H-K9 material as an example, its refractive index is 1.5067. According to the refraction law, its refraction angle θ2 = 27.989°. At this time, θ4 = θ2 + 45° = 72.989°. The b surface is composed of multiple layers of films ( Figure 5 shown), where the refractive index n H of the high refractive index film layer zirconia is 2.1224, and the refractive index n L of the low reflection film layer silica is 1.449, and both are low absorption materials. The light beam can be divided into transmitted light and reflected light after passing through the b surface. The reflected light exits from the c surface, and the transmitted light exits from the d surface. Since the c surface is perpendicular to the a surface and the d surface is parallel to the a surface, finally the two light beams both exit from the c surface and the d surface at θ3 = 45°. Therefore, the final two laser beams are parallel output and parallel to the incident laser.

[0060] The second half-wave plate 403 of the L-shaped adjustable beam splitter 401 changes the polarization states of the s-polarized light and p-polarized light, and can adjust the beam splitting ratio of the beam on the b surface of the octahedral beam splitter 407. For the transmittance and reflectivity of the b surface, they can be obtained according to Fresnel's law.

[0061]

[0062] Total reflectivity = r s +r p Total transmittance = t s +t p . Figure 6 The beam transmittance and reflectivity are calculated according to the polarization state of the incident light. It can be proved that when the polarization of the incident light is adjusted to an appropriate polarization state, a 1:1 beam splitting can be achieved. In summary, the laser beam can be divided into two laser beams with consistent energy, adjustable spacing, and parallel output by the octahedral beam splitter 407.

[0063] The principle of the octahedral beam splitter 407 is based on the reflection and transmission principle of Fresnel's formula. According to Fresnel's formula, the linearly polarized light incident on an interface can be divided into s-polarized light and p-polarized light. The reflectivity and transmittance of the s-polarized light and p-polarized light can be obtained through the formula respectively. As long as the incident angle and the material are determined, the reflectivity and transmittance of the s-polarized light, and the reflectivity and transmittance of the p-polarized light are determined. By planning the ratio of the s-polarization state and p-polarization state of the incident light, the overall reflectivity and transmittance can be adjusted (overall reflectivity = reflection of s-polarized light + reflection of p-polarized light) (overall transmittance = transmission of s-polarized light + transmission of p-polarized light). The purpose of the octahedral beam splitter 407 is to output a 1:1 beam.

[0064] Among them, the third reflector 405 is controlled by the displacement driving device 406 to move horizontally, adjust the position of the reflected light entering the a surface of the octahedral beam splitter 407, and further adjust the spacing between the two laser beams emitted from the c surface and d surface of the octahedral beam splitter 407. In the present invention, a small displacement stage mirror system is adopted, and the third reflector 405 is controlled by the displacement driving device 406 to move horizontally, dynamically adjust the incident position of the beam on the a surface of the octahedral beam splitter 407, and realize flexible control of the spacing between the two laser beams emitted from the c surface and d surface of the octahedral beam splitter 407 to meet different requirements for the line spacing.

[0065] In a specific embodiment, the octahedral beam splitter 407 is obtained by cutting off two symmetric corners from a cube beam splitter. As Figure 3 shown, in the octahedral beam splitter 407, X5 = X1 + X2 + X3. Use X4 to represent the set position of the incident light to the octahedral beam splitter 407, where X3 = X5 - (X1 + X2), Finally obtained For an incident light beam with a diameter of 6 mm, the displacement driving device 406 (small displacement stage) is used to adjust the position of the light beam irradiating the octahedral beam splitter 407. If the X5 of the octahedral beam splitter 407 is 25.4 mm and it is made of H-K9 material, the adjustable range of Δd can be achieved within 0 - 10.83 mm.

[0066] Among them, the vertical plate 2 is driven by the X-axis moving platform 3 and can move along the X-axis direction; the focusing lens array 408 is driven by the Z-axis moving platform 5 and can move along the Z-axis. Specifically, the vertical plate 2 is fixed on the X-axis moving platform 3, and the incident laser always maintains collimated and horizontal irradiation. The multi-channel laser scribing processing system can realize scribing with a fixed interval on the surface of the scribing sample 8. The focusing lens array 408 is fixed on the Z-axis moving platform 5, and the up and down movement of the focusing lens array 408 is adjusted through the Z-axis moving platform 5 to achieve the focusing of the split laser beam.

[0067] Among them, multiple laser beams derived from the front beam splitting and etching device 4 and multiple laser beams derived from the back beam splitting and etching device 7 are arranged in an interleaved manner, and the lenses in the corresponding focusing lens array 408 are also interleaved. In the present invention, the front / back beam splitting and etching device adopts a symmetric design, realizes double-sided synchronous etching through an interleaved optical path layout, and can also realize scribing with a small pitch, ensuring processing consistency. In specific applications, the scribing pitch can be further reduced by stacking multiple vertical plates 2 to achieve scribing with a smaller pitch and improve processing accuracy.

[0068] This embodiment also provides a solar cell processing device, including the above multi-channel laser scribing processing system.

[0069] The present invention solves the problems of high cost, large energy loss, and insufficient flexibility in multi-optical path systems through dynamic beam splitting regulation, a symmetric optical path architecture, and optimization of the octahedral beam splitter 407, significantly improving the efficiency, precision, and economy of laser scribing of solar cells. Dynamic beam splitting regulation mechanism: The L-shaped adjustable beam splitter 401 (polarizing beam splitter 402 + double half-wave plates 403) is used to precisely regulate the polarization state by rotating the angle of the half-wave plate 403, achieving continuous adjustment of the beam splitting ratio and reducing energy loss. Combining with the small displacement stage mirror system, the incident position of the beam on the octahedral beam splitter 407 is dynamically adjusted to flexibly control the distance between the two beams emitted by the octahedral beam splitter 407, meeting the requirements of different scribing distances. Symmetric staggered optical path architecture: The front / back beam splitting and etching devices adopt a symmetric design, realizing double-sided synchronous etching through a staggered optical path layout, and can also achieve small-spacing scribing to ensure processing consistency. In specific applications, the scribing distance can be further reduced by stacking multiple vertical plates 2 to achieve scribing with a smaller distance and improve processing accuracy. Moreover, the symmetric optical path design ensures the synchronism of double-sided etching. Combining with the sub-micron spot control ability of the octahedral beam splitter 407, the dead zone width can be reduced, and the effective power generation area of the battery can be increased. Optimization design of the octahedral beam splitter 407: The octahedral beam splitter 407 using a specific coating material (such as zirconia / silica) achieves high-precision beam splitting based on Fresnel's law, and ensures parallel outgoing optical paths through geometric structure optimization (such as cube cutting design). System integration and miniaturization: Key components such as the L-shaped beam splitter and displacement stage mirror are highly integrated, reducing the number of optical elements (such as avoiding multi-stage polarizing beam splitters), significantly shrinking the volume of the optical system, being applicable to industrial-grade precision processing equipment, and reducing the occupied space and cost of the equipment.

[0070] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-channel laser scribing processing system, characterized in that It includes a beam splitting prism, a vertical plate, a front beam splitting and etching device, a first reflector, and a back beam splitting and etching device; The beam splitting ratio of the beam splitting prism is 50:50, which is used to evenly divide a single beam of laser into two output beams. One output beam directly enters the front beam splitting and etching device vertically downward, and the other output beam is redirected by the first reflector and then vertically downward into the back beam splitting and etching device. The front beam splitting and etching device and the back beam splitting and etching device have the same structure; The front beam splitting and etching device includes two L-shaped adjustable beam splitters with the same structure, a second reflector, a third reflector, an octahedron beam splitter, and a focusing lens array; The two L-shaped adjustable beam splitters and the second reflector are sequentially arranged on the optical path of the output beam from top to bottom. The L-shaped adjustable beam splitter is used to regulate the polarization state of the input beam, and then divide the beam into two orthogonally polarized beams, which are respectively transmitted and reflected to form transmitted light and reflected light. The transmitted light vertically enters the L-shaped adjustable beam splitter or the second reflector directly below. The reflected light in the L-shaped adjustable beam splitter and the reflected light reflected by the second reflector are respectively input into the corresponding third reflector horizontally backward after polarization state regulation. The reflected light after being reflected by the third reflector vertically enters the upper vertical plane a of the corresponding octahedron beam splitter. The beam entering the octahedron beam splitter is divided into transmitted light and reflected light by the upper vertical plane b of the octahedron beam splitter. Its reflected light and transmitted light are respectively emitted from the lower two vertical planes c and d of the octahedron beam splitter. The two emitted laser beams are then focused on the scribed sample surface by the corresponding lenses in the focusing lens array.

2. The multi-channel laser scribing processing system according to claim 1, wherein The L-shaped adjustable beam splitter is composed of a polarization beam splitter inclined at 45° and two half-wave plates respectively located at the light inlet and the light outlet. The half-wave plate at the light inlet can rotate the angle to regulate the polarization direction of the input linearly polarized laser. Then, the output beam is decomposed into two orthogonally polarized beams by the polarization beam splitter, and the two orthogonally polarized beams are respectively transmitted and reflected to form vertically downward transmitted light and horizontal reflected light, and the continuous adjustment of the beam splitting ratio of these two beams can be achieved. Among them, the horizontal reflected light is regulated again by the half-wave plate at the light outlet for the polarization direction of its linearly polarized light.

3. The multi-channel laser scribing processing system according to claim 2, wherein The reflected light reflected by the second reflector is regulated for its polarization state by the half-wave plate arranged at the back.

4. The multi-channel laser scribing processing system according to claim 1, wherein The upper vertical plane b of the octahedron beam splitter is composed of multiple layers of film materials, and each layer of film material includes a high refractive index film layer and a low refractive index film layer arranged in sequence.

5. The multi-channel laser scribing processing system according to claim 4, characterized in that, The high refractive index film layer is made of zirconia material, and the low refractive index film layer is made of silica material.

6. The multi-channel laser scribing processing system according to claim 5, characterized in that, The thickness of the high refractive index film layer and the high transmission film is λ / 4 or an integer multiple of it, where λ is the wavelength of the laser; the number of film layers of the high refractive index film layer and the high transmission film is 10 - 30 layers.

7. The multi-channel laser scribing processing system according to claim 1, wherein The third reflector is controlled by a displacement driving device to move horizontally, so as to adjust the position of the reflected light entering the a plane of the octahedron beam splitter, and further adjust the distance between the two laser beams emitted from the c plane and the d plane of the octahedron beam splitter.

8. The multi-channel laser scribing processing system according to claim 1, wherein, The vertical plate is driven by the X-axis moving platform and can move along the X-axis direction; the focusing lens array is driven by the Z-axis moving platform and can move along the Z-axis.

9. The multi-channel laser scribing processing system according to claim 1, wherein, Multiple laser beams derived from the front beam splitting and etching device and multiple laser beams derived from the back beam splitting and etching device are arranged in an interleaved manner.

10. A solar cell processing device, characterized in that, It includes the multi-path laser scribing processing system according to any one of claims 1 to 9.

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