Laser equipment for solar cell patterning

Abstract

The utility model relates to laser equipment for solar cell patterning, belongs to the technical field of photovoltaic modules, and solves the problem that precision and efficiency cannot be improved simultaneously in the laser patterning process of solar cells in the prior art. The device comprises a laser light source used for outputting a laser beam; the first beam splitter is used for splitting the laser beam into a first light beam and a second light beam; the vortex light converter and the first light beam adjusting assembly are used for adjusting the solid light spot of the first light beam into a hollow annular light spot with the required shape and size; the second light beam adjusting assembly is used for adjusting the shape and size of the light spot of the second light beam to be the same as the hollow part of the hollow annular light spot; and the second beam splitter is used for combining the first light beam and the second light beam. The laser beam is divided into two light beams, the shapes and the sizes of the two light beams are adjusted respectively, finally, the large light spot, the small light spot and the annular light spot with the adjustable sizes are combined and output, and the machining efficiency and the machining precision can be improved at the same time.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic module technology, and in particular to a laser device for patterning solar cells. Background Technology

[0002] Laser patterning technology uses a laser beam to ablate or etch the surface of solar cells. By precisely controlling parameters such as laser wavelength, power, pulse frequency, scanning speed, and focusing method, the desired pattern is formed on the cell surface. In this process, laser energy is precisely focused on the cell surface, causing localized heating and resulting in material stripping and ablation, thereby forming a textured structure with a certain depth and shape.

[0003] In this process, the laser spot size is related to the size of the grid lines in the pattern. Generally, the width of the grid lines in a printed pattern is not always equal. A larger spot size results in higher efficiency but lower patterning precision; conversely, a smaller spot size results in lower efficiency but higher patterning precision. Existing laser equipment cannot achieve both high precision and high efficiency in laser patterning. Utility Model Content

[0004] The present invention aims to provide a laser device for patterning solar cells, thereby solving the problem that it is impossible to simultaneously improve accuracy and efficiency in the laser patterning process of solar cells.

[0005] On one hand, this utility model provides a laser device for patterning solar cells, comprising: a laser source for outputting a laser beam; a first beam splitter for splitting the laser beam output by the laser source into a first beam and a second beam with different optical paths; a vortex converter for converting a solid spot of the first beam into a hollow annular spot; a first beam adjustment component for adjusting the shape and size of the hollow annular spot; a second beam adjustment component for adjusting the shape and size of the solid spot of the second beam to be the same as the shape and size of the hollow portion of the hollow annular spot after adjustment by the first beam adjustment component; and a second beam splitter for merging the first beam adjusted by the first beam adjustment component and the second beam adjusted by the second beam adjustment component, wherein the spot of the merged beam is a large solid spot with the spot of the first beam as the edge and the spot of the second beam as the center.

[0006] Furthermore, the laser source outputs a Gaussian beam; or / and, the first beam splitter is a neutral beam splitter; or / and, the vortex light converter is a vortex waveplate, a spiral phase plate, or a spatial light modulator.

[0007] Furthermore, the first beam adjustment assembly includes a first beam expander collimator for expanding the diameter of the first beam and reducing the divergence angle of the first beam; the second beam adjustment assembly includes a second beam expander collimator for expanding the diameter of the second beam and reducing the divergence angle of the second beam.

[0008] Furthermore, the first beam adjustment component further includes a first aperture stop, which is disposed after the first beam expander collimator and is used to adjust the spot size of the first beam; the second beam adjustment component further includes a second aperture stop, which is disposed after the second beam expander collimator and is used to adjust the spot size of the second beam.

[0009] Furthermore, both the first beam expander collimator and the second beam expander collimator are composed of two convex lenses, which are arranged sequentially along the optical path direction, and the focal length of the convex lens located in front of the optical path direction is smaller than the focal length of the convex lens located behind the optical path direction.

[0010] Furthermore, the first beam adjustment assembly further includes a first shaping mirror, which is disposed after the first aperture, and is used to adjust the shape and energy distribution of the first beam; the second beam adjustment assembly further includes a second shaping mirror, which is disposed after the second aperture, and is used to adjust the shape and energy distribution of the second beam.

[0011] Furthermore, both the first shaping mirror and the second shaping mirror are freeform surfaces with inconsistent curvature at various points. The first shaping mirror is used to adjust the first beam into a hollow square flat-top beam, and the second shaping mirror is used to adjust the second beam into a solid square flat-top beam.

[0012] Furthermore, the first beam adjustment assembly also includes a polarizer, which is disposed between the first aperture and the first shaping mirror.

[0013] Furthermore, it also includes a first reflector and a second reflector. The first reflector is disposed between the first beam splitter and the vortex light converter, and is used to reflect the first beam to the vortex light converter. The second reflector is disposed after the second beam adjustment assembly, and is used to reflect the second beam after being shaped by the second shaping mirror to the second beam splitter.

[0014] Furthermore, it also includes a galvanometer and a field mirror; the galvanometer and the field mirror are sequentially arranged after the second beam splitter; the combined beam, after passing through the galvanometer and the field mirror, can illuminate the solar cell to achieve laser patterning of the solar cell.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0016] (1) In this utility model, the emitted light from the laser source is divided into a first beam and a second beam by a first beam splitter. Then, the first beam is adjusted into a hollow ring of the required shape and size by a vortex light converter and a first beam adjustment component. The second beam is adjusted into the shape and size of the hollow part of the first beam by a second beam adjustment component. The first beam and the second beam are then combined to output a large spot beam with the second beam as the center and the first beam as the edge. Alternatively, only the second beam, i.e., a small spot beam, or only the first beam, i.e., a beam with a hollow ring spot, can be output. The three outputs can be switched arbitrarily. When processing coarse grid lines, a large spot is output; when processing fine grid lines, a small spot is output; and when processing grid lines of special shapes, a hollow ring spot is output. This meets the requirements for patterning solar cells, thereby improving processing accuracy while ensuring processing efficiency.

[0017] (2) This invention uses a first beam expander and a second beam expander to adjust the size of the first and second beams and reduce the beam divergence angle, thereby making the beams more concentrated during transmission, reducing beam diffusion and distortion, and improving the overall quality of the beams. It also ensures a more uniform energy distribution in the beam spot, which is beneficial for uniform etching during laser mold making. Furthermore, since both beams originate from the same laser, the consistency of their frequency, phase, and polarization state is ensured. After beam combining, they can still be considered as a single laser beam, which helps guarantee processing accuracy.

[0018] (3) This utility model can adjust the size of the first beam and the second beam by means of the first aperture and the second aperture, thereby adjusting the size of the final output beam.

[0019] (4) The present invention achieves the adjustment of the first beam into a hollow square ring by the first shaping mirror and the adjustment of the second beam into a solid square by the second shaping mirror, and the energy distribution of the light spot is uniform.

[0020] (5) This utility model uses a polarizer to adjust the polarization state of the first beam, so that the first beam can output only the two opposite sides of the hollow square, so that the light spot of the final output beam is rectangular, thereby further expanding the applicability of this device.

[0021] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages will become apparent from the description or be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained from the description and accompanying drawings, which are particularly pointed out. Attached Figure Description

[0022] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0023] Figure 1 This is a schematic diagram of a laser device for patterning solar cells provided in Embodiment 1 of this application;

[0024] Figure 2 This is a schematic diagram of the structure of a laser device for patterning solar cells provided in Embodiment 1 of this application.

[0025] Figure label:

[0026] 100 - Laser; 200 - First beam splitter; 31 - First optical path; 311 - First reflecting mirror; 312 - Vortex converter; 313 - First beam expander and collimator; 314 - First aperture; 315 - First shaping mirror; 32 - Second optical path; 323 - Second beam expander and collimator; 324 - Second aperture; 325 - Second shaping mirror; 326 - Second reflecting mirror; 400 - Second beam splitter; 500 - Galvanometer; 600 - Field mirror; 700 - Solar cell. Detailed Implementation

[0027] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0028] Example 1

[0029] A specific embodiment of this utility model is as follows: Figures 1-2 As shown, a laser device for patterning solar cells is disclosed, including a laser source, and a first beam splitter 200, a vortex light converter 312, a first beam adjustment component, a second beam adjustment component, a second beam splitter 400, a galvanometer 500, and a field mirror 600 disposed on the light output path of the laser source.

[0030] The laser source is a laser 100 that can output a Gaussian beam, and the wavelength of the output beam of the laser 100 is in the visible light wavelength range.

[0031] The first beam splitter 200 is preferably a neutral beam splitter. The first beam splitter 200 splits the laser beam emitted from the laser source into a first beam (i.e., a reflected beam) and a second beam (i.e., a transmitted beam) with mutually perpendicular directions. A vortex converter 312 and a first beam adjustment component are sequentially arranged on the first optical path 31 of the first beam. The vortex converter 312 is used to convert the solid spot of the first beam into a hollow annular spot; the first beam adjustment component is used to adjust the shape and size of the hollow annular spot. A second beam adjustment component is arranged on the second optical path 32 of the second beam, capable of adjusting the shape and size of the second beam spot to be the same as the shape and size of the hollow portion of the hollow annular spot after adjustment by the first beam adjustment component.

[0032] The second beam splitter 400 is preferably a neutral beam splitter. The second beam splitter 400 can combine the first beam regulated by the first beam adjustment component and the second beam regulated by the second beam adjustment component. The combined beam has a large, solid spot with the spot of the first beam as its edge and the spot of the second beam as its center. After passing through the galvanometer 500 and the field lens 600, the combined beam can illuminate the solar cell 700 to achieve laser patterning of the solar cell 700. Specifically, the galvanometer 500 controls the beam direction according to the laser pattern; the field lens 600 directs the focal point of the incident beam from the galvanometer 500 onto the solar cell 700 in a direction perpendicular to the solar cell 700.

[0033] The laser device in this embodiment can output a large spot beam centered on the second beam and with the first beam as its edge; it can also output only the second beam (small spot beam) or only the first beam (hollow ring beam) by adjusting the first beam adjustment component and / or the second beam adjustment component. These three outputs can be switched arbitrarily. A large spot size is used when laser processing continuous grid lines, while in places where high patterning accuracy is required, such as grid breaks, an aperture is used to reduce the size of the spot, so that the patterned laser pattern can achieve a balance between carrier collection and leakage current, thereby improving processing accuracy while ensuring processing efficiency.

[0034] See Figures 1-2 The first beam first passes through the first reflector 311 to change its direction, so that the direction of the first beam is parallel to the direction of the second beam. This facilitates the spatial arrangement of the entire device and makes the device structure compact and small.

[0035] The first reflecting mirror 311 reflects the first beam to the vortex light converter 312. The vortex light converter 312 is a vortex waveplate, a spiral phase plate, or a spatial light modulator, which can convert Gaussian light into vortex light. After the first beam passes through the vortex light converter 312, it is converted from a Gaussian beam into a vortex beam. The wavefront of the vortex beam is a hollow ring, and its energy distribution is concentrated in the ring.

[0036] In this embodiment, the first beam adjustment component includes a first beam expander collimator 313, a first aperture 314, and a first shaping mirror 315 arranged sequentially.

[0037] The first beam expander collimator 313 is used to enlarge the spot size and reduce the laser divergence angle. The first beam expander collimator 313 consists of two convex lenses, which are arranged one in front of the other along the optical path. The focal length of the two convex lenses is smaller in front and larger in back. The front one is the first convex lens and the back one is the second convex lens.

[0038] The first aperture 314 is used to control the spot size and limit beam transmission. The first aperture 314 uses conventional standard optical components. The aperture size of the first aperture 314 can be electrically adjusted to adjust the spot size of the first optical path.

[0039] The first shaping mirror 315 is a freeform surface with inconsistent curvature, which transforms a beam with a Gaussian wavefront energy distribution into a flat-top beam, thus redistributing the energy of the vortex beam within the hollow annular spot area. The first shaping mirror 315 can also shape the spot of the first beam into various hollow annular shapes, such as circular, square, rectangular, and hexagonal rings, as needed. Preferably, the first shaping mirror 315 shapes the spot of the first beam into a hollow square ring.

[0040] The second beam adjustment assembly has the same structure as the first beam adjustment assembly, and also includes a second beam expander collimator 323, a second aperture 324, and a second shaping mirror 325 arranged sequentially.

[0041] The second beam expander collimator 323 is used to expand the size of the Gaussian beam in the second optical path split by the first beam splitter 200, thereby reducing the laser divergence angle. The second beam expander collimator 323 consists of two convex lenses arranged sequentially along the optical path, with the focal length of the first convex lens located in front of the optical path being smaller than the focal length of the second convex lens located behind the optical path. The ratio of the focal length of the second convex lens in the first beam expander collimator 313 to the focal length of the second convex lens in the second beam expander collimator 323 is equal to the ratio of the beam spot diameter after passing through the first beam expander collimator 313 to the beam spot diameter after passing through the second beam expander collimator 323. By adjusting the focal lengths of the two second convex lenses, the beam spots of the first and second beams can be made to fit together perfectly.

[0042] The second aperture 324 is used to control the spot size and limit beam transmission. The second aperture 324 uses conventional standard optical elements. Normally, the second aperture 324 is kept at its maximum opening to avoid gaps between the edge and center of the final output beam spot. In special cases, the aperture size of the second aperture 324 can also be electrically adjusted.

[0043] The second shaping mirror 325 is a freeform surface with inconsistent curvature, which transforms a beam with a Gaussian wavefront energy distribution into a flat-top beam, redistributing the energy of the vortex beam within a solid spot area. The second shaping mirror 325 can also shape the second beam into various shapes such as circles, squares, rectangles, and hexagons according to the shape of the first beam, so that the spot of the second beam can be precisely embedded in the hollow position of the hollow annulus of the first beam. Preferably, the second shaping mirror 325 shapes the spot of the second beam into a solid square.

[0044] After being adjusted by the second beam adjustment component, the second beam changes direction through the second reflector 326 and is incident on the second beam splitter 400.

[0045] The second beam splitter 400 can combine the hollow annular beam of the first optical path, which has been adjusted by the first beam adjustment component, and the solid beam of the second optical path, which has been adjusted by the second beam adjustment component, into a beam with a solid large spot.

[0046] The galvanometer 500 is used to control the beam direction according to the laser pattern.

[0047] The field lens 600 is used to direct the focal point of the incident beam from the galvanometer onto the solar cell 700 in a direction perpendicular to the solar cell. The beam required for patterning the solar cell consists of two parts: the outer edge of the light spot and the center of the light spot. The size of the light spot is controlled by the aperture, allowing for arbitrary output of the desired light spot size.

[0048] The laser device for patterning solar cells in this embodiment outputs laser spots of corresponding size and shape by controlling the opening and closing of the aperture. The final spot consists of an outer edge and a center. These two beams pass through first and second collimating lenses with relatively low magnification, resulting in a more uniform energy distribution, which is beneficial for uniform etching during laser patterning. Simultaneously, the two beams originate from the same laser, ensuring consistency in frequency, phase, and polarization state. After beam combining, they can still be considered as a single laser beam, greatly improving the accuracy of laser patterning.

[0049] Example 2

[0050] The laser device for patterning solar cells in Embodiment 2, based on Embodiment 1, further includes a polarizer in the first beam adjustment component. The polarizer is disposed in the first optical path 31, located between the first aperture 314 and the first shaping mirror 315. By adjusting the rotation angle of the polarizer, the spot shape of the first beam after passing through the first shaping mirror 315 is changed to the two opposite sides of a hollow square ring.

[0051] In this way, the final output beam can be a rectangle formed by the second beam as the center and the first beam as both sides.

[0052] Furthermore, the polarizer can automatically rotate to adjust the polarization direction of the beam, thereby changing the spot shape of the first beam. This allows the laser device to adjust the spot shape and size of the output laser beam according to actual needs, thereby improving productivity while ensuring patterning accuracy.

[0053] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A laser device for patterning of solar cells, characterized in that The application relates to a laser beam shaping device. The application comprises: a laser light source for outputting a laser beam; a first beam splitter for splitting the laser beam output by the laser light source into a first beam and a second beam with different light path directions; a vortex light converter for converting a solid spot of the first beam into a hollow annular spot; a first beam adjusting assembly for adjusting the shape and size of the hollow annular spot; a second beam adjusting assembly for adjusting the shape and size of a solid spot of the second beam to be the same as the shape and size of a hollow part of the hollow annular spot after the first beam adjusting assembly adjusts the hollow annular spot; 2. The laser device for solar cell patterning according to claim 1, wherein, a second beam splitter for combining the first beam after the first beam adjusting assembly adjusts and the second beam after the second beam adjusting assembly adjusts, and the spot of the combined beam is a solid large spot with the spot of the first beam as an edge and the spot of the second beam as a center. The laser light source outputs a Gaussian beam; Or / and, The first beam splitter is a neutral beam splitter; Or / and, 3. The laser device for solar cell patterning according to claim 1 or 2, characterized in that, The vortex light converter is a vortex wave plate, a spiral phase plate or a spatial light modulator.

4. The laser device for solar cell patterning according to claim 3, wherein, The first beam adjusting assembly comprises a first beam expander and collimator for expanding the diameter of the first beam and reducing the divergence angle of the first beam; and the second beam adjusting assembly comprises a second beam expander and collimator for expanding the diameter of the second beam and reducing the divergence angle of the second beam.

5. The laser device for solar cell patterning according to claim 3, wherein, The first beam adjusting assembly further comprises a first diaphragm arranged behind the first beam expander and collimator, and the first diaphragm is used for adjusting the size of the spot of the first beam; and the second beam adjusting assembly further comprises a second diaphragm arranged behind the second beam expander and collimator, and the second diaphragm is used for adjusting the size of the spot of the second beam.

6. The laser device for solar cell patterning according to claim 4, wherein, The first beam expander and collimator and the second beam expander and collimator are both composed of two convex lenses, the two convex lenses are arranged in sequence along the light path direction, and the focal length of the convex lens located in front along the light path direction is smaller than the focal length of the convex lens located behind along the light path direction.

7. The laser device for solar cell patterning according to claim 6, wherein, The first beam adjusting assembly further comprises a first shaping mirror arranged behind the first diaphragm, and the first shaping mirror is used for adjusting the shape and energy distribution of the first beam; and the second beam adjusting assembly further comprises a second shaping mirror arranged behind the second diaphragm, and the second shaping mirror is used for adjusting the shape and energy distribution of the second beam.

8. The laser device for solar cell patterning according to claim 6, wherein, The first shaping mirror and the second shaping mirror are both free curved surfaces with inconsistent curvatures, the first shaping mirror is used for adjusting the first beam into a hollow square flat-top beam, and the second shaping mirror is used for adjusting the second beam into a solid square flat-top beam.

9. The laser device for solar cell patterning according to claim 1, wherein, The first beam adjusting assembly further comprises a polarizer arranged between the first diaphragm and the first shaping mirror. The application further comprises a first reflector and a second reflector. The first mirror is arranged between the first beam splitter and the vortex light converter, and is used for reflecting the first light beam to the vortex light converter. The second mirror is arranged behind the second light beam adjusting assembly, and is used for reflecting the second light beam to the second beam splitter.

10. The laser device for solar cell patterning according to claim 1, wherein, Further comprising a galvanometer and a field lens; the galvanometer and the field lens are arranged in sequence behind the second beam splitter; the combined light beam can irradiate on a solar cell to realize laser patterning on the solar cell after passing through the galvanometer and the field lens.

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