A multi-channel laser scribing system and solar cell processing equipment

Abstract

This invention discloses a multi-path laser scribing system and solar cell processing equipment. It employs an L-shaped adjustable beam splitter (polarizing beam splitter + double half-wave plates), where the polarization state is controlled by rotating the half-wave plates to achieve continuously adjustable beam splitting ratio. Combined with a small displacement stage mirror to adjust the beam incident position of the octahedral beam splitter, dynamic control of the dual-beam spacing is achieved to adapt to different scribing spacing requirements. The front / back beam splitting etching device adopts a symmetrical layout, supporting simultaneous double-sided etching and smaller spacing processing through staggered optical paths and multiple stacked plates, improving processing consistency and precision. The octahedral beam splitter is optimized to ensure high-precision beam splitting of the parallel output optical path. The system highly integrates key components such as the L-shaped beam splitter and displacement stage mirror, reducing the number of optical elements and significantly shrinking the optical system size. It is suitable for industrial-grade precision processing equipment, reducing equipment space and cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cell processing, in particular to a multi-channel laser scribing processing system and a solar cell processing equipment. BACKGROUND

[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 by high-energy laser beams, achieving non-contact processing, and the precision directly determines the size of the "dead zone" of the battery module, i.e. the non-power generation area from the outermost side of the P1 line to the outermost side of the P3 line. Studies have shown that for every 10 μm reduction in 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 service life of the module. Therefore, modern laser scribing systems need to compress the line width to below 50 μm while ensuring that the P1 / P2 / P3 lines do not overlap, which requires sub-micron accuracy for beam control. In addition, the spacing between adjacent cells is generally between 5 mm and 10 mm, which also requires higher light splitting for scribing equipment.

[0003] Common laser processing techniques are mainly divided into single-channel laser etching and multi-channel laser etching. Single-channel laser etching systems rely on a laser and a simple optical design, although the structure is simple and the cost is low, but it is difficult to meet the needs of processing and detection, and the processing efficiency is low. Multi-channel light splitting processing system realizes laser energy reconstruction through diffractive optical element (DOE) or spatial light modulator (SLM). The DOE scheme uses micro-nano structures to decompose a single laser beam into multiple energy uniformly distributed (fluctuation <5%) parallel beams, and through dynamic focal spot compensation technology to ensure that each focal point is synchronized within ±1 μm. The SLM-based scheme is more flexible and can adjust the number of light splitting (4-64 channels) and spatial arrangement in real time through phase encoding, especially suitable for customized processing of batteries.

[0004] However, the existing multi-channel light splitting processing system has the following defects:

[0005] 1. Multi-beam parallel etching is performed by mechanical light splitting, which uses more devices, and the mechanical structure of the equipment is complex and the cost is high. When light splitting mechanically, polarizing beam splitter and half-wave plate are used to control the energy of each beam. The polarizing beam splitter and the wave plate are used to construct a light splitting array (such as the patent scheme of CN116117332A), and the single-stage light splitting efficiency loss is about 15%, and the patent scheme uses multiple light splitting elements, which must have a large overall laser power loss.

[0006] 2. The multi-beam parallel etching is performed by the way of splitting light with a diffractive optical element, and the multi-beams split by the diffractive optical element have problems such as uneven spot intensity distribution, only single repeated structure can be processed, limited processing precision, wavelength sensitivity and the like. Meanwhile, the diffractive optical element needs precise microstructure design and manufacturing, and usually adopts technologies such as photolithography and electron beam etching, which have high requirements on equipment and high cost;

[0007] 3. The light is split by a spatial light modulator, and the spatial light modulator has a small damage threshold, so the laser can easily damage the spatial light modulator.

[0008] The present application optimizes the overall optical structure of the current splitting system composed of multiple polarization beam splitters and mirrors, constructs a dynamic energy coupling assembly containing an L-shaped adjustable attenuator, realizes fine adjustment of the splitting intensity, reduces the number of devices, and reduces energy loss. SUMMARY

[0009] In order to solve the technical problems in the above background art, the present application provides a multi-channel laser scribing processing system and a solar cell processing equipment, which can not only realize multi-channel processing, but also realize continuous adjustment of the splitting light intensity, the spacing of the processing light path is adjustable, can adapt to the requirements of battery scribing of various scribing spacings, reduces the number of devices, and reduces energy loss.

[0010] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0011] The first aspect of the present application provides a multi-channel laser scribing processing system, which comprises a light splitting prism, a vertical plate, a front beam splitting etching device, a first mirror and a back beam splitting etching device.

[0012] The light splitting ratio of the light splitting prism is 50:50, which is used to divide a single beam of laser into two output beams, one of which is directly vertically downward into the front beam splitting etching device, and the other of which is introduced into the back beam splitting etching device after being turned by the first mirror, and the front beam splitting etching device and the back beam splitting etching device have the same structure.

[0013] The front beam splitting etching device comprises two L-shaped adjustable beam splitters with the same structure, a second mirror, a third mirror, an octahedral beam splitter and a focusing lens array.

[0014] Two L-shaped adjustable beam splitters and a second reflecting mirror are arranged sequentially from top to bottom in the optical path of the output beam. The L-shaped adjustable beam splitter is used to control the polarization state of the input beam, and then splits the beam into two orthogonally polarized beams, which are transmitted and reflected respectively to form transmitted light and reflected light. The transmitted light enters vertically downward into the L-shaped adjustable beam splitter or the second reflecting mirror located directly below. The reflected light in the L-shaped adjustable beam splitter and the reflected light reflected from the second reflecting mirror are horizontally input to the corresponding third reflecting mirror after polarization state control. The reflected light after reflection by the third reflecting mirror enters vertically downward into the vertical surface a of the corresponding octahedral beam splitter located above. The beam entering the octahedral beam splitter is split into transmitted light and reflected light by the vertical surface b of the octahedral beam splitter located above. The reflected light and transmitted light are emitted from the two vertical surfaces c and d of the octahedral beam splitter located below, respectively. The two emitted laser beams are then focused onto the surface of the scribing sample by the corresponding lenses in the focusing lens array.

[0015] A further improvement is that the L-shaped adjustable beam splitter consists of a polarizing beam splitter tilted at 45° and two half-wave plates located at the light inlet and light outlet, respectively. The half-wave plate at the light inlet can be rotated to adjust the polarization direction of the input linearly polarized laser. The polarizing beam splitter then decomposes the output beam into two orthogonally polarized beams, which are then transmitted and reflected to form a vertically downward transmitted beam and a horizontally reflected beam, respectively. The splitting ratio of these two beams can be continuously adjusted. The horizontally reflected beam is further adjusted by the half-wave plate at the light outlet to control the polarization direction of its linearly polarized light. The function of the second half-wave plate is to control the splitting ratio of the octahedral beam splitter.

[0016] In this invention, the beam intensity is continuously adjusted using an L-shaped adjustable attenuator beam splitter (polarizing beam splitter + double half-wave plate). The specific principle is as follows:

[0017] The laser light input to the L-shaped adjustable beam splitter is linearly polarized. The first component in the L-shaped adjustable beam splitter is a half-wave plate (λ / 2 wave plate), which modulates the polarization state of the linearly polarized light by introducing a phase difference of π. When 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 component of the L-shaped adjustable beam splitter is a polarization beam splitter set at a 45° angle. The principle of the polarization beam splitter is based on birefringence (s-polarized reflection / p-polarized transmission) or polarization-selective reflection, which decomposes the incident light into two orthogonally polarized beams (such as s-beams and p-beams). 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. For example, s-beams are reflected, and p-beams are transmitted, thus achieving beam splitting of polarization states. Therefore, by adjusting the L-shaped adjustable beam splitter, the rotation angle θ of the first half-wave plate can achieve precise control of the polarization state of the L-shaped beam, thereby controlling the splitting ratio of transmitted and reflected light. The reflected light then passes through the second half-wave plate, whose function is to precisely control the polarization state of the reflected light, thus controlling the splitting ratio of the octahedral beam splitter. When incident on the dielectric film of the octahedral beam splitter, linear polarization can be decomposed into the synthesis of p-light and s-light; adjusting the direction of linear polarization can control the synthesis ratio of the p-light and s-light.

[0018] A further improvement is that the polarization state of the reflected light from the second mirror is controlled by a half-wave plate placed behind it.

[0019] In this invention, two L-shaped adjustable beam splitters are arranged in the vertical optical path transmission direction, and a second reflecting mirror is arranged at the bottom to reflect the transmitted light emitted by the second L-shaped adjustable beam splitter. The polarization state of the beam is then precisely controlled by a half-wave plate arranged behind it, thereby controlling the beam splitting ratio of the subsequent beam entering the octahedral beam splitter.

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

[0021] A further improvement is that the vertical surface b of the octahedral beam splitter is composed of multiple layers of film, each layer including a high refractive index film layer and a low refractive index film layer arranged sequentially.

[0022] Specifically, the high refractive index film is made of zirconium dioxide, and the low refractive index film is made of silicon dioxide.

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

[0024] In this invention, an octahedral beam splitter is optimized. Specifically, an octahedral beam splitter with a specific coating material (such as zirconium dioxide / silicon dioxide) is used to achieve high-precision beam splitting based on Fresnel's law, and parallel outgoing light paths are ensured through geometric optimization (such as cube cutting design).

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

[0026] This invention employs a small displacement stage reflector system. A displacement driving device controls the third reflector to move horizontally, dynamically adjusting the incident position of the beam on the a-face of the octahedral beam splitter. This enables flexible control of the distance between the two laser beams emitted from the c-face and d-face of the octahedral beam splitter, adapting to different scribe line spacing requirements.

[0027] A further improvement is that the upright plate is driven by an X-axis moving platform and can move along the X-axis; 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 moving platform, and the incident laser is always collimated and horizontally irradiated. The multi-channel laser scribing system can scribing lines at fixed intervals on the sample surface. The focusing lens array is fixed on the Z-axis moving platform, and the focusing lens array is moved up and down by adjusting the Z-axis moving platform to achieve focusing of the split laser beam.

[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 in an alternating manner.

[0030] The front / back beam-splitting etching apparatus of this invention adopts a symmetrical design and achieves simultaneous etching on both sides through an interleaved optical path layout. It can also achieve small-pitch scribing, ensuring processing consistency. In practical applications, the scribing spacing can be further reduced by using multiple stacked plates to achieve even smaller scribing spacing and improve processing accuracy.

[0031] In a second aspect, the present invention provides a solar cell processing apparatus, including the aforementioned multi-channel laser scribing system.

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

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

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

[0035] (3) Symmetrical staggered optical path architecture: The front / back beam-splitting etching apparatus adopts a symmetrical design, achieving simultaneous etching on both sides through a staggered optical path layout. It can also achieve small-pitch scribing, ensuring processing consistency. In practical applications, multiple stacked plates can be used to further reduce the scribing spacing, achieving even smaller scribing spacing and improving processing accuracy. Furthermore, the symmetrical optical path design ensures the synchronicity of double-sided etching, and combined with the sub-micron-level spot control capability of the octahedral beam splitter, the dead zone width can be reduced, increasing the effective power generation area of ​​the battery.

[0036] (4) Octahedral beam splitter optimization design: an octahedral beam splitter using a specific coating material (such as zirconium dioxide / silicon dioxide) achieves high-precision beam splitting based on Fresnel's law, and ensures parallel outgoing light path through geometric structure optimization (such as cube cutting design).

[0037] (5) System integration and miniaturization: The key components such as L-shaped beam splitter and shift stage reflector are highly integrated to reduce the number of optical elements (such as avoiding multi-stage polarization beam splitters), significantly reduce the size of the optical system, and make it suitable for industrial precision processing equipment, reducing the space occupied and cost of the equipment. Attached Figure Description

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

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

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

[0041] Figure 3 This is a schematic diagram of the structure of the back beam-splitting etching device in this invention;

[0042] Figure 4 This is a schematic diagram illustrating the specific structure of the octahedral beam splitter in this invention;

[0043] Figure 5 This is a diagram illustrating the layered structure of plane b of the octahedral beam splitter in this invention.

[0044] Figure 6 This relates to the relationship between the polarization change of the incident light and the reflectivity and transmittance of the b-face of the octahedral beam splitter in this invention.

[0045] The specific reference numerals in the attached figures are as follows:

[0046] 1. Beam splitter prism; 2. Vertical plate; 3. X-axis moving platform; 4. Front beam splitting etching device; 4. L-shaped adjustable beam splitter; 401. Polarizing beam splitter; 402. Half-wave plate; 403. Second reflector; 404. Third reflector; 405. Displacement driving device; 406. Octahedral beam splitter; 407. Focusing lens array; 408. Z-axis moving platform; 5. First reflector; 6. Back beam splitting etching device; 7. Scribbled sample; 8. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] This embodiment provides a multi-channel laser scribing system, such as... Figures 1 to 3 As shown, it includes a beam splitter 1, a vertical plate 2, a front beam splitting etching device 4, a first reflecting mirror 6, and a back beam splitting etching device 7;

[0049] The beam splitter prism 1 has a beam splitting ratio of 50:50, which is used to split a single laser beam into two output beams. One output beam enters the front beam splitting etching device 4 directly and vertically downwards, while the other output beam is directed vertically downwards after being turned by the first reflector 6 and guided to the back beam splitting etching device 7. The front beam splitting etching device 4 and the back beam splitting etching device 7 have the same structure.

[0050] The front beam splitting etching apparatus 4 includes two identical 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.

[0051] Two L-shaped adjustable beam splitters 401 and a second reflecting mirror 404 are arranged sequentially from top to bottom in the optical path of the output beam. The L-shaped adjustable beam splitter 401 is used to control the polarization state of the input beam, splitting the beam into two orthogonally polarized beams, which are then transmitted and reflected to form transmitted and reflected light, respectively. The transmitted light enters vertically downward into the L-shaped adjustable beam splitter 401 or the second reflecting mirror 404 located directly below. The reflected light from the L-shaped adjustable beam splitter 401 and the reflected light from the second reflecting mirror 404 are then horizontally input backward after polarization state control. In the corresponding third reflecting mirror 405, the reflected light after being reflected by the third reflecting mirror 405 enters vertically downwards into the vertical surface a of the corresponding octahedral beam splitter 407 located above. The beam entering the octahedral beam splitter 407 is split into transmitted light and reflected light by the vertical surface b of the octahedral beam splitter 407 located above. The reflected light and transmitted light are emitted from the two vertical surfaces c and d of the octahedral beam splitter 407 located below, respectively. The two emitted laser beams are then focused onto the surface of the scribing sample 8 by the corresponding lenses in the focusing lens array 408.

[0052] The L-shaped adjustable beam splitter 401 consists of a polarizing beam splitter 402 tilted at 45° and two half-wave plates 403 located at the light inlet and light outlet, respectively. The half-wave plate 403 located at the light inlet can be rotated to adjust the polarization state of the input beam. The polarizing beam splitter 402 then decomposes the output beam into two orthogonally polarized beams, and the two orthogonally polarized beams are transmitted and reflected to form vertically downward transmitted light and horizontal reflected light, respectively. The horizontal reflected light is adjusted in polarization state by the half-wave plate 403 located at the light outlet.

[0053] In this invention, continuous adjustment of the split beam intensity is achieved through an L-shaped adjustable attenuator beam splitter (polarizing beam splitter 402 + double half-wave plates 403). The specific principle is as follows: The laser light input to the L-shaped adjustable beam splitter 401 is linearly polarized light. The first component in the L-shaped adjustable beam splitter 401 is a half-wave plate 403 (λ / 2 wave plate), which modulates 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 component of the L-shaped adjustable beam splitter 401 is a polarizing beam splitter 402 tilted at 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 beams (such as s-beams and p-beams). When unpolarized or mixed-polarized light is incident, the device uses the optical anisotropy of the material or a specific coating to separate light with different polarization directions through refraction or reflection. For example, s-light is reflected, while p-light is transmitted, thus achieving beam splitting of polarization states. 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 beam splitting, thereby controlling the splitting ratio of transmitted and reflected light. Additionally, the reflected light passes through the second half-wave plate 403, whose function is to precisely control the polarization state of the reflected light, thereby controlling the splitting ratio of the octahedral beam splitter 407.

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

[0055] Polarizing beamsplitter 402 is based on Brewster's angle of incidence. Therefore, the polarizing beamsplitter film must be cemented between a high-refractive-index prism. Light must enter the beamsplitter film from within the prism medium to satisfy the Brewster's angle of complete polarization condition. Besides polarizing beamsplitter 402, there is also a planar beamsplitter where light enters from air onto the beamsplitter film. Planar beamsplitters are also based on the principle of refraction and reflection, but they do not generate polarization effects through Brewster's angle.

[0056] The polarization beam splitter 402 can only achieve full polarization at a specific incident angle. However, in practical applications, the incident angle may fluctuate, or a beam may be incompletely collimated, resulting in diverging / converging light. Therefore, it is essential to understand the characteristics of the polarization beam splitter 402 under fluctuating incident angle conditions. When the incident angle at the film interface deviates from the Brewster angle, the reflected light still contains an s-ray component, and its amplitude reflection coefficient does not change significantly. However, a p-ray component is also generated in the reflected light, causing the extinction ratio of the reflected light to decrease rapidly, while the transmitted light maintains a high degree of polarization. However, since some p-rays are reflected, the intensity of the transmitted light decreases accordingly. It is evident that the polarization beam splitting characteristics of the polarization beam splitter 402 are highly sensitive to the incident angle.

[0057] In this invention, the reflected light from the second reflector 404 is polarized by a half-wave plate 403 positioned behind it. Two L-shaped adjustable beam splitters 401 are arranged in the vertical optical path transmission direction, with a second reflector 404 positioned at the bottom. The second reflector 404 reflects the transmitted light emitted from the second L-shaped adjustable beam splitter 401, and the polarization state of the beam is precisely controlled by the half-wave plate 403, thereby controlling the splitting ratio of the subsequent beam entering the octahedral beam splitter 407. In practical applications, the number of L-shaped adjustable beam splitters 401 can be adjusted.

[0058] Among them, such as Figure 4 and Figure 5 As shown, the octahedral beam splitter 407 is obtained by cutting off two symmetrical corners of a cubic beam splitter. The upper vertical surface b of the octahedral beam splitter 407 is composed of multiple layers of film, each layer including a high-refractive-index layer and a low-refractive-index layer arranged sequentially. Specifically, the high-refractive-index layer is made of zirconium dioxide, and the low-refractive-index layer is made of silicon dioxide. The design of the high-refractive-index and low-refractive-index layers must meet specific transmittance and reflectance requirements and maintain stable performance within the target wavelength range. Preferably, the thickness of the high-refractive-index and low-refractive-index layers is λ / 4 or an integer multiple thereof, where λ is the wavelength of the laser; the number of high-refractive-index and low-refractive-index layers is 10 to 30.

[0059] In this invention, the octahedral beam splitter 407 is optimized. Specifically, the octahedral beam splitter 407, using a specific coating material (such as zirconium dioxide / silicon dioxide), achieves high-precision beam splitting based on Fresnel's law, and ensures a parallel output light path through geometric optimization (such as a cube-cut design). In a specific embodiment, the reflected light output by the third reflecting mirror 405 is incident on the a-plane of the octahedral beam splitter 407 at θ1 = 45°. The material of the octahedral beam splitter 407 is transparent glass; taking H-K9 material as an example, its refractive index is 1.5067, and according to the law of refraction, its refraction angle θ2 = 27.989°. At this time, θ4 = θ2 + 45° = 72.989°. The b-plane is composed of a multilayer film (…). Figure 5 As shown), the refractive index n of the high-refractive-index film layer, zirconium dioxide, is... H The refractive index n of the low-reflectivity silicon dioxide film is 2.1224. L The absorptivity is 1.449, indicating that both are low-absorption materials. The beam passing through surface b can be divided into transmitted and reflected light. The reflected light exits from surface c, and the transmitted light exits from surface d. Since surface c is perpendicular to surface a and surface d is parallel to surface a, both beams ultimately exit from surfaces c and d at an angle of θ3 = 45°. Therefore, the two final laser beams are parallel to each other and parallel to the incident laser beam.

[0060] The second half-wave plate 403 of the L-shaped adjustable beam splitter 401 changes the polarization states of the s-ray and p-ray, thereby adjusting the beam splitting ratio at the b-plane of the octahedral beam splitter 407. The transmittance and reflectance of the b-plane can be calculated using Fresnel's law. Total reflectivity = r s +r p Total transmittance = t s +t p . Figure 6 The transmittance and reflectance of the laser beam are calculated based on the polarization state of the incident light. It can be proven that when the polarization of the incident light is adjusted to a suitable state, a 1:1 beam splitting can be achieved. In summary, the laser beam can be split into two laser beams with the same energy, adjustable spacing, and parallel output by the octahedral beam splitter 407.

[0061] The octahedral beam splitter 407 operates on the principle of reflection and transmission based on Fresnel's formula. According to Fresnel's formula, linearly polarized light incident on an interface can be divided into s-rays and p-rays. The reflectivity and transmittance of s-rays and p-rays can be obtained using formulas. Given a fixed incident angle and material, the reflectivity and transmittance of both s-rays and p-rays are determined. By planning the ratio of the s-polarization state to the p-polarization state of the incident light, the overall reflectivity and transmittance can be adjusted (overall reflectivity = s-ray reflection + p-ray reflection) and (overall transmittance = s-ray transmission + p-ray transmission). The goal of the octahedral beam splitter 407 is simply to achieve a 1:1 beam output.

[0062] In this invention, the third reflecting mirror 405 is controlled by the displacement driving device 406 to move horizontally, adjusting the position of the reflected light entering the a-face of the octahedral beam splitter 407, and thus adjusting the distance between the two laser beams emitted from the c-face and d-face of the octahedral beam splitter 407. This invention employs a small displacement stage reflecting mirror system, where the displacement driving device 406 controls the horizontal movement of the third reflecting mirror 405, dynamically adjusting the incident position of the beam on the a-face of the octahedral beam splitter 407, thereby achieving flexible control of the distance between the two laser beams emitted from the c-face and d-face of the octahedral beam splitter 407 to adapt to different scribe line spacing requirements.

[0063] In a specific embodiment, the octahedral beam splitter 407 is obtained by cutting off two symmetrical corners of a cubic beam splitter, such as... Figure 3 As shown, in the octahedral beam splitter 407, there exists X5 = X1 + X2 + X3, and X4 is used to represent the position of the incident light on the octahedral beam splitter 407. X2=X5*tanθ2,X3=X5-(X1+X2), Finally, it was concluded For an incident beam with a diameter of 6 mm, the position of the beam illuminating the octahedral beam splitter 407 is adjusted using a displacement drive device 406 (small displacement stage). If the X5 of the octahedral beam splitter 407 is 25.4 mm and is made of H-K9 material, the spacing Δd can be adjusted within the range of 0-10.83 mm.

[0064] The vertical plate 2 is driven by the X-axis moving platform 3 and can move along the X-axis; 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 is always kept collimated and horizontally irradiated. The multi-channel laser scribing system can achieve scribing at fixed intervals on the surface of the scribing sample 8. The focusing lens array 408 is fixed on the Z-axis moving platform 5, and the vertical movement of the focusing lens array 408 is adjusted by the Z-axis moving platform 5 to achieve focusing of the split laser beam.

[0065] In this invention, the multiple laser beams derived from the front beam-splitting etching device 4 and the multiple laser beams derived from the back beam-splitting etching device 7 are arranged in an alternating pattern, and the lenses in the corresponding focusing lens array 408 are also staggered. The front / back beam-splitting etching devices in this invention adopt a symmetrical design, achieving simultaneous double-sided etching through an alternating optical path layout. This also enables small-pitch scribing, ensuring processing consistency. In practical applications, the scribing spacing can be further reduced by using multiple stacked vertical plates 2, achieving even smaller scribing spacing and improving processing accuracy.

[0066] This embodiment also provides a solar cell processing device, including the above-mentioned multi-channel laser scribing processing system.

[0067] This invention addresses the problems of high cost, high energy loss, and insufficient flexibility in multi-optical-path systems through dynamic beam splitting control, a symmetrical optical path architecture, and optimization of the octahedral beam splitter 407, significantly improving the efficiency, accuracy, and economy of laser etching for solar cells. The dynamic beam splitting control mechanism employs an L-shaped adjustable beam splitter 401 (polarizing beam splitter 402 + dual half-wave plates 403). By rotating the half-wave plates 403, the polarization state is precisely controlled, achieving continuous adjustment of the beam splitting ratio and reducing energy loss. Combined with a small displacement stage reflector system, the incident position of the beam on the octahedral beam splitter 407 is dynamically adjusted, enabling flexible control of the spacing between the two beams emitted from the octahedral beam splitter 407 to adapt to different etching spacing requirements. The symmetrical staggered optical path architecture uses a symmetrical design for the front / back beam splitting etching device. A staggered optical path layout enables simultaneous etching on both sides, achieving small-pitch etching and ensuring processing consistency. In practical applications, multiple stacked plates 2 can be used to further reduce the etching spacing, achieving even smaller spacing and improving processing accuracy. Furthermore, the symmetrical optical path design ensures synchronous etching on both sides. Combined with the sub-micron level spot control capability of the octahedral beam splitter 407, the dead zone width can be reduced, increasing the effective power generation area of ​​the battery. Optimized design of the octahedral beam splitter 407: The octahedral beam splitter 407, using specific coating materials (such as zirconium dioxide / silicon dioxide), achieves high-precision beam splitting based on Fresnel's law, and ensures a parallel output light path through geometric optimization (such as a cube-cut design). System integration and miniaturization: Key components such as the L-shaped beam splitter and the shift stage mirror are highly integrated, reducing the number of optical elements (such as avoiding multi-stage polarization beam splitters), significantly reducing the size of the optical system, making it suitable for industrial-grade precision machining equipment, and reducing equipment space and cost.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-pass laser scribe processing system, comprising: The device comprises a beam splitter prism, a vertical plate, a front beam splitting etching device, a first mirror and a back beam splitting etching device. The beam splitter prism has a splitting ratio of 50:50 and is used to split a single laser beam into two output beams, one of which is directly vertically downward into the front beam splitting etching device, and the other of which is vertically downward into the back beam splitting etching device after being turned by the first mirror. The front beam splitting etching device comprises two L-shaped adjustable beam splitters, a second mirror, a third mirror, an octahedral beam splitter and a focusing lens array. The two L-shaped adjustable beam splitters and the second mirror are sequentially arranged on the light path of the output beam from top to bottom, and the L-shaped adjustable beam splitter is used to adjust the polarization state of the input light beam, and then split the light beam into two beams of orthogonally polarized light and transmit and reflect them respectively to form transmitted light and reflected light, the transmitted light is vertically downward into the L-shaped adjustable beam splitter or the second mirror located directly below, the reflected light in the L-shaped adjustable beam splitter and the reflected light reflected by the second mirror are horizontally backward input into the corresponding third mirror after polarization state adjustment, and the reflected light reflected by the third mirror is vertically downward into the corresponding vertical face a of the octahedral beam splitter located above, and the light beam entering the interior of the octahedral beam splitter is split into transmitted light and reflected light through the vertical face b of the octahedral beam splitter located above, the reflected light and the transmitted light are emitted from the two vertical faces c and d of the octahedral beam splitter located below, and the two beams of laser light are focused to the scribing sample surface by the corresponding lenses in the focusing lens array.

2. The multi-pass laser scribe processing system of claim 1, wherein, The L-shaped adjustable beam splitter is composed of a 45° inclined polarization beam splitter and two half-wave plates located at the light inlet and light outlet respectively, the half-wave plate located at the light inlet can be rotated to adjust the polarization direction of the input linearly polarized laser light, then the output light beam is decomposed into two beams of orthogonally polarized light by the polarization beam splitter, and the two beams of orthogonally polarized light are transmitted and reflected respectively to form vertically downward transmitted light and horizontally reflected light, and the splitting ratio of the two beams of light can be continuously adjusted, and the polarization direction of the horizontally reflected light is adjusted again by the half-wave plate located at the light outlet.

3. The multi-pass laser scribe processing system of claim 2, wherein, The reflected light reflected by the second mirror is adjusted in polarization state by the half-wave plate arranged behind.

4. The multi-pass laser scribe processing system of claim 1, wherein, The vertical face b of the octahedral beam splitter located above is composed of multiple layers of film materials, and each layer of film material comprises a high refractive index film layer and a low refractive index film layer arranged in sequence.

5. The multi-pass laser scribe processing system of claim 4, wherein, The high refractive index film layer is made of zirconium dioxide, and the low refractive index film layer is made of silicon dioxide.

6. The multi-pass laser scribe processing system of claim 5, wherein, The thickness of the high refractive index film layer and the low refractive index film layer is λ / 4 or an integer multiple of λ / 4, and λ is the wavelength of the laser light; the number of layers of the high refractive index film layer and the low refractive index film layer is 10-30.

7. The multi-pass laser scribe processing system of claim 1, wherein, The third mirror is controlled by a displacement driving device to move horizontally, so as to adjust the position of the reflected light entering the vertical face a of the octahedral beam splitter, and further adjust the distance between the two beams of laser light emitted from the vertical faces c and d of the octahedral beam splitter.

8. The multi-pass laser scribe processing system of claim 1, wherein, 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.

9. The multi-pass laser scribe processing system of claim 1, wherein, 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 in a staggered manner.

10. A solar cell processing apparatus characterized by comprising: The multi-laser scribing system comprises the multi-laser scribing system as claimed in any one of claims 1 to 9.

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