Method for manufacturing photovoltaic metal screen
By combining chemical etching and laser engraving, the problems of low production efficiency and high cost of photovoltaic metal mesh have been solved, achieving high-precision mesh manufacturing at high efficiency and low cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG ZHONGLING TECH CO LTD
- Filing Date
- 2026-02-06
- Publication Date
- 2026-07-03
AI Technical Summary
Existing pure laser engraving technology results in low production efficiency and high costs for photovoltaic metal mesh, and the excessively long laser processing time has become a bottleneck restricting production capacity.
Chemical etching is used to form a semi-etched hole with a depth of D1. Combined with a visual positioning system and laser technology, the semi-etched hole is first formed on the second surface of the metal substrate, and then the remaining thickness is penetrated by laser, so as to achieve rapid forming of screen printing through holes.
It significantly shortens laser processing time by about 50%, increases equipment capacity and utilization, reduces the manufacturing cost of a single stencil, and ensures graphic accuracy and quality.
Smart Images
Figure CN121650333B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and in particular to a method for manufacturing a photovoltaic metal mesh. Background Technology
[0002] In the manufacturing process of photovoltaic cells, metallization is a key step in forming electrodes, typically achieved using a silver paste printing process. This process relies on a high-precision metal stencil densely covered with micropores that allow the silver paste to pass through. Currently, the mainstream method for manufacturing such high-precision metal stencils is laser etching technology, which uses a high-energy laser beam to directly ablate and penetrate a full-thickness metal substrate to form patterned through-holes.
[0003] However, this pure laser processing method has significant inherent drawbacks. Due to the absorption and thermal conductivity characteristics of the metal substrate to laser energy, to cleanly and vertically penetrate the entire thickness of the substrate (typically 10-15 micrometers) in one go, the laser beam needs to repeatedly etch at the same location multiple times. This results in extremely long laser processing times for a single screen. For example, producing a standard-sized photovoltaic screen can take up to approximately 6 hours in total. This excessively long processing time severely restricts equipment and personnel productivity, leading to low production efficiency per screen and high manufacturing costs, thus becoming a bottleneck in reducing the overall cost of photovoltaic cells.
[0004] Therefore, there is an urgent need for a new manufacturing method that can significantly shorten laser processing time, improve screen printing efficiency, and ensure graphic accuracy and hole wall quality, in order to solve the technical problems of production capacity bottleneck and high cost caused by the existing pure laser engraving technology. Summary of the Invention
[0005] The purpose of this application is to provide a method for manufacturing photovoltaic metal mesh, which can significantly shorten laser processing time, improve mesh manufacturing efficiency, and ensure graphic accuracy and hole wall quality. This new manufacturing method solves the technical problems of production capacity bottleneck and high cost caused by existing pure laser engraving technology.
[0006] A method for manufacturing a photovoltaic metal mesh screen includes the following steps:
[0007] S10, a metal substrate with a thickness of H1 is provided, the metal substrate having a first surface and a second surface opposite to each other, a mask layer having a target pattern is formed on the second surface of the metal substrate, the target pattern including a plurality of hole patterns distributed in an effective area and at least two alignment mark patterns located outside the effective area;
[0008] S20, with the mask layer as protection, chemical etching is performed on the second surface of the metal substrate to form a semi-etched hole with a depth of D1, while the alignment mark pattern is etched into an alignment through hole penetrating the metal substrate.
[0009] S30, Remove the mask layer;
[0010] S40, based on the alignment through-hole, the position of the semi-etched hole is aligned from the first surface of the metal substrate using a visual positioning system, and the bottom of the semi-etched hole is laser-etched to form an etched through-hole penetrating the metal substrate.
[0011] In one embodiment, step S40, which involves aligning the position of the semi-etched hole from the first surface of the metal substrate using a visual positioning system and laser-etching the bottom of the semi-etched hole to form an etched through-hole penetrating the metal substrate, specifically includes:
[0012] S401, the image acquisition device of the visual positioning system captures an image containing at least two of the alignment through holes;
[0013] S402, Process the image and identify the actual pixel coordinates of the center or feature point of each alignment hole;
[0014] S403, compare the actual pixel coordinates with the preset theoretical coordinates corresponding to the target graphic, and calculate the coordinate transformation parameters or position deviation.
[0015] S404, according to the coordinate transformation parameters or position deviation, adjust the processing coordinate system of the laser to make the predetermined path of the laser spot coincide with the projection position of the semi-etched hole on the first surface, so as to form an etched through hole penetrating the metal substrate.
[0016] In one embodiment, step S402, the method for identifying the alignment via feature points includes: extracting the edge of the alignment via using an image processing algorithm, and determining its center coordinates by at least one of geometric center calculation, pattern matching, or crosshair center fitting.
[0017] In one embodiment, step S10 specifically includes:
[0018] S101, a protective film is applied to the first surface of the metal substrate;
[0019] S102, a dry film is pressed onto the second surface of the metal substrate;
[0020] S103, the dry film is exposed using a film mask containing the target pattern;
[0021] S104, the exposed dry film is developed to remove the dry film in the areas of the hole pattern and the alignment mark pattern, thereby forming the mask layer.
[0022] In one embodiment, in step S101, the protective film is a laser-permeable polyester film or polyimide film, so that laser engraving can be performed in step S40 without removing the protective film.
[0023] In one embodiment, the development in step S104 is performed by spray development using a sodium carbonate solution with a concentration of 1.0%-1.5%.
[0024] In one embodiment, in step S20, the chemical etching solution used to form the semi-etched hole is a ferric chloride solution, and the concentration of free acid in the ferric chloride etching solution is controlled at 1.0% ± 0.2%;
[0025] Step S20 is performed using a continuous spray etching machine, with the etching temperature controlled at 40℃±5℃.
[0026] In one embodiment, in step S40, the laser is an ultraviolet laser or a picosecond laser, and the spot diameter is 10 micrometers to 30 micrometers.
[0027] In one embodiment, the method further includes the following steps prior to step S10:
[0028] S01, providing a metal substrate with a thickness of H; the thickness of the metal substrate with a thickness of H is between 20 micrometers and 30 micrometers;
[0029] S02, perform double-sided chemical etching on the metal substrate with thickness H to thin it to a target thickness H1, wherein the target thickness H1 is 10 micrometers to 15 micrometers.
[0030] In one embodiment, the depth D1 is 6 micrometers to 8 micrometers, and the depth of the laser lithography is H1 to D1.
[0031] This application has at least the following advantages or beneficial effects:
[0032] 1. The photovoltaic metal mesh fabrication method disclosed in this application reconstructs the process for forming through-holes in the mesh. In the background technology, the formation of through-holes relies entirely on the "subtractive" process of laser ablation. The reason for the long processing time is that the laser needs to independently handle the entire workload from scratch to complete penetration of the entire substrate thickness. However, the photovoltaic metal mesh fabrication method disclosed in this application breaks down this process into two collaborative stages: "chemical etching semi-etching" and "laser fine-tuning penetration." In step S20, a semi-etched hole with a depth of D1 is pre-formed on the second surface through chemical etching. That is, most of the volume of the final through-hole (corresponding to the depth D1) has been completed by a highly efficient, batch-processable parallel chemical method. In step S40, the laser only needs to handle the penetration of the remaining thickness (H1-D1). The direct effect is that the material thickness to be processed by the laser is reduced by about D1, which significantly shortens the laser action time for a single hole. This greatly reduces the overall mesh laser processing time of about 6 hours in the background technology, directly solving the problem of low production efficiency.
[0033] 2. The photovoltaic metal mesh fabrication method involved in this application ensures the accuracy and feasibility of the hybrid process through an innovative alignment system. In steps S10 and S20, while forming functional semi-etched holes, the alignment mark pattern is simultaneously etched into through-holes. The design of the alignment through-holes provides a physical reference for the laser finishing in step S40. Subsequently, the laser equipment captures these alignment through-holes through a vision system, and can accurately calculate the projection position of the semi-etched hole pattern on the first surface, thereby achieving seamless integration of laser and chemical etching patterns. The technical solution of etching the alignment mark pattern into alignment through-holes penetrating the metal substrate solves the pattern alignment problem in the hybrid process of chemical etching followed by laser etching, ensuring the positional accuracy of the final etched through-holes, so that increased production capacity does not come at the expense of quality.
[0034] 3. The photovoltaic metal mesh fabrication method involved in this application optimizes the time-consuming laser processing into a composite process combining chemical etching roughing (rapid mass production) with laser finishing (rapid and precise penetration). Its core advantages are: 1) significantly shortening the laser processing time of a single mesh (expectedly reduced by approximately 50%), directly improving equipment capacity and utilization; 2) significantly reducing the manufacturing cost of a single mesh due to the elimination of the main capacity bottleneck; and 3) ensuring process reliability and high-precision graphics through a built-in alignment marking system. Therefore, this method effectively overcomes the shortcomings of the prior art described in the background section, providing a practical and feasible technical solution for achieving efficient, low-cost, and high-precision photovoltaic metal mesh fabrication. Attached Figure Description
[0035] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0036] Figure 1 A flowchart illustrating the method for manufacturing a photovoltaic metal mesh screen provided in this application embodiment;
[0037] Figure 2 A schematic diagram illustrating the manufacturing process of the photovoltaic metal mesh provided in this application embodiment;
[0038] Figure 3A This is a schematic diagram illustrating how existing technologies use laser etching to create etched through-holes on metal substrates.
[0039] Figure 3B This is a schematic diagram simulating the effect of forming etched through holes on a metal substrate using only laser engraving in existing technologies;
[0040] Figure 4A This is a schematic diagram illustrating the process of forming etched through-holes on a metal substrate using the photovoltaic metal mesh fabrication method described in this application embodiment.
[0041] Figure 4B This is a schematic diagram simulating the effect of forming etched through holes on a metal substrate using the photovoltaic metal mesh fabrication method described in this application. Detailed Implementation
[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0043] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0045] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0046] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0047] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0048] Please see Figure 1 and Figure 2 This application provides a method for manufacturing a photovoltaic metal mesh screen, comprising the following steps:
[0049] S10, a metal substrate is provided, the metal substrate having opposing first and second surfaces, and a mask layer having a target pattern is formed on the second surface of the metal substrate. The target pattern includes a plurality of hole patterns distributed in an effective area and at least two alignment mark patterns located outside the effective area. The metal substrate may be a sheet or strip of SUS301 or SUS304 stainless steel.
[0050] In one embodiment, the following steps S01 and S02 are included before step S10. S01, providing a metal substrate with a thickness of H (such as...) Figure 2 As shown). The thickness of the metal substrate with thickness H is 20-30 micrometers. S02, the metal substrate with thickness H is subjected to double-sided chemical etching to thin it to the target thickness H1 (as shown). Figure 2As shown), the target thickness H1 is 10-15 micrometers. For example, a 22-micrometer metal substrate can be thinned to 12 micrometers, a 20-micrometer metal substrate to 10 micrometers, or a 25-micrometer metal substrate to 13 micrometers. The etching solution used for double-sided chemical etching is a ferric chloride solution.
[0051] In step S20, with a mask layer as protection, chemical etching is performed on the second surface of the metal substrate to form a half-etched hole of depth D1, while simultaneously etching the alignment mark pattern into a through-hole penetrating the metal substrate. In one embodiment, the chemical etching depth D1 for forming the half-etched hole can be set to 6-8 micrometers, for example, in some embodiments D1 can be set to 6.5 micrometers, 7.0 micrometers, 7.5 micrometers, or 8 micrometers. The chemical etching for forming the half-etched hole can be performed using a continuous etching line, and the etching solution used can be a ferric chloride solution. The etching depths of the half-etched hole and the through-hole are different. The etching depth of the through-hole is greater than that of the half-etched hole. The etching depth of the through-hole is approximately 10-12 micrometers. By setting different opening sizes for the half-etched hole and the through-hole, these two different etching depths are achieved in a single chemical etching process. Figure 2 As shown, in the last sub-step of S10, the opening size 'a' of the half-etched hole and the opening size 'b' of the aligned through-hole are specified. Figure 2 As shown, in step S20, the etching depth of the semi-etched hole is A, and the etching depth of the aligned through hole is B. Where a < b, A < B. Multiple experiments have shown that the larger the opening size, the deeper the etching depth for the same chemical etching time. Specifically, when the difference between b and a is 4 micrometers, the difference between B and A is 6 micrometers. Finally, A is the chemical etching depth D1 of the semi-etched hole, and B is the target thickness H1 of the metal substrate to be thinned.
[0052] S30, Remove the mask layer. In this step, a 2%-5% potassium hydroxide solution can be used for mask stripping and cleaning under ultrasonic assistance.
[0053] S40, based on the alignment via, the position of the semi-etched hole is aligned from the first surface of the metal substrate using a visual positioning system, and the bottom of the semi-etched hole is laser-etched to form an etched via through the metal substrate. In this step, the laser used in the laser-etching process can be an ultraviolet laser or a picosecond laser. The working thickness of the laser-etching (from the semi-etched hole to the etched via) is 4-6 micrometers, which reduces the working time of laser-etching by 40% to 60% compared to directly laser-etching holes on the full-thickness metal substrate. In the above embodiments of this application, most of the hole depth is formed by chemical etching (forming a semi-etched hole with a thickness of D1), and then the remaining thickness is penetrated by laser-etching, wherein the working thickness of the laser-etching does not exceed 6 micrometers. In the above embodiments of this application, the sidewall of the semi-etched hole formed by chemical etching in step S20 is sloped (specifically as shown in the figure). Figure 4A As shown in the lower middle view, 'viewing from side B towards side A'; as Figure 4B The thickness of the half-etched hole on the lower side is D1 (as shown in step S40). The sidewall of the through hole formed by laser etching in step S40 is vertical (specifically as shown in step S40). Figure 4A As shown in the 'viewing from side A to side B' perspective from the upper middle side; as Figure 4B The through-hole on the upper middle side has a thickness of H1-D1 (as shown).
[0054] In this embodiment, the process for forming through-holes in the screen printing plate is first reconstructed. In the background technology, the formation of through-holes relies entirely on the "subtractive" process of laser ablation. The reason for the long processing time is that the laser needs to independently handle the entire workload from scratch to complete penetration of the entire substrate thickness. However, the photovoltaic metal screen printing plate manufacturing method involved in this application breaks down this process into two collaborative stages: "chemical etching semi-etching" and "laser fine-tuning penetration". In step S20, a semi-etched hole with a depth of D1 is pre-formed on the second surface through chemical etching. That is, most of the volume of the final through-hole (corresponding to the depth D1) has been completed by a highly efficient, batch-processable parallel chemical method. In step S40, the laser only needs to handle the penetration of the remaining thickness (H1-D1). The direct effect is that the material thickness to be processed by the laser is reduced by about D1, which shortens the laser action time of a single hole by a factor of two. This significantly reduces the overall screen printing plate laser processing time of about 6 hours in the background technology, directly solving the pain point of low production efficiency.
[0055] Secondly, an innovative alignment system ensures the precision and feasibility of the hybrid process. In steps S10 and S20, while forming functional semi-etched holes, the alignment mark pattern is simultaneously etched into through-holes. The design of the alignment through-holes provides a physical reference for the laser finishing in step S40. Subsequently, the laser equipment captures these alignment through-holes through a vision system, which can accurately calculate the projection position of the semi-etched hole pattern on the first surface, thereby achieving seamless integration of laser and chemical etching patterns. The technical solution of etching the alignment mark pattern into alignment through-holes penetrating the metal substrate solves the pattern alignment problem in the hybrid process of chemical etching followed by laser etching, ensuring the positional accuracy of the final etched through-holes, so that increased production capacity does not come at the expense of quality.
[0056] In summary, the photovoltaic metal mesh fabrication method described in this application optimizes the time-consuming laser processing into a composite process combining chemical etching for roughing (rapid mass production) and laser finishing (rapid and precise penetration). Its core advantages are: 1) It significantly shortens the laser processing time of a single mesh (expectedly reduced by approximately 50%), directly improving equipment capacity and utilization. 2) Due to the elimination of the main capacity bottleneck, the manufacturing cost of a single mesh is significantly reduced. 3) The built-in alignment marking system ensures the reliability of the process and the high precision of the pattern. Therefore, this method effectively overcomes the shortcomings of the prior art described in the background section, providing a practical technical solution for achieving efficient, low-cost, and high-precision photovoltaic metal mesh fabrication.
[0057] In one embodiment, the depth D1 is 6-8 micrometers, and the laser engraving depth is H1-D1. The laser engraving depth H1-D1 is approximately in the range of 4-6 micrometers.
[0058] In this embodiment, the entire workload of processing a 10-12 micrometer thick metal substrate from scratch until complete penetration of the substrate thickness is handled by laser etching. This is adjusted to two collaborative stages: "chemical etching semi-shaping" and "laser fine-tuning penetration." These two collaborative stages reduce the material thickness required for laser processing by approximately D1, significantly shortening the single-hole laser processing time. This substantially reduces the overall screen printing laser processing time, which previously required approximately 6 hours, and reduces the laser etching working thickness by more than 40%.
[0059] In one embodiment, step S40, "aligning the position of the semi-etched hole from the first surface of the metal substrate using a visual positioning system and laser etching the bottom of the semi-etched hole to form an etched through-hole penetrating the metal substrate," specifically includes the following steps:
[0060] S401, the image acquisition device of the vision positioning system captures an image containing at least two alignment through-holes. In one embodiment, the image acquisition device is a CCD camera or a CMOS camera, which is integrated into the laser equipment via a coaxial optical path or a side-axis method.
[0061] S402 processes the image and identifies the actual pixel coordinates of the center or feature point of each alignment via.
[0062] S403 compares the actual pixel coordinates with the preset theoretical coordinates corresponding to the target graphic to calculate the coordinate transformation parameters or position deviation. The coordinate transformation parameters include one or more of the following: translation, rotation, and scaling factor.
[0063] S404, adjust the processing coordinate system of the laser according to the coordinate transformation parameters or position deviation, so that the predetermined path of the laser spot coincides with the projection position of the semi-etched hole on the first surface, so as to form an etched through hole through the metal substrate.
[0064] In this embodiment, the image preprocessing step effectively suppresses interference from noise and uneven illumination, preventing erroneous alignment data caused by abnormal image acquisition or temporary contamination from flowing into subsequent stages. This avoids the risk of batch processing defects and improves the stability and yield of the entire process. In this embodiment, a complete and closed-loop feature recognition process is formed from image input, processing, calculation to result verification, making this key technology node fully public, repeatable, and verifiable.
[0065] In one embodiment, step S402, the method for identifying the alignment via feature points includes: extracting the edges of the alignment via using an image processing algorithm, and determining its center coordinates by at least one of geometric center calculation, pattern matching, or crosshair center fitting.
[0066] This embodiment provides different methods to process the edges of alignment vias, solving the problems of accuracy and stability in alignment mark recognition. The algorithms described above, which use geometric center calculation, pattern matching, or crosshair center fitting, can effectively resist interference from image noise, uneven illumination, and other factors, and reliably and repeatedly calculate high-precision alignment reference coordinates.
[0067] In other embodiments, other alignment methods can be used to align the laser etching of the first surface (A surface) and the chemical etching of the second surface (B surface) to ensure the formation of the through hole.
[0068] In one embodiment, step S10 specifically includes:
[0069] S101, a protective film is applied to the first surface of the metal substrate.
[0070] S102, a dry film is laminated onto the second surface of a metal substrate.
[0071] S103 exposes the dry film using a film mask containing the target pattern.
[0072] S104, develop the exposed dry film to remove the dry film in the areas of the hole pattern and the alignment mark pattern, thereby forming a mask layer.
[0073] In this embodiment, by coordinating the application of a protective film to the first surface and the fabrication of a dry film mask on the second surface, single-sided, high-precision patterning on a metal substrate is achieved. This embodiment also clarifies the photolithography process flow for forming the mask layer (film application → exposure → development), simultaneously fabricating the hole pattern for printing and the alignment mark pattern in the same photolithography step. The above-described process in this embodiment can stably achieve micron-level or even higher resolution pattern transfer, ensuring sharp mask edges, meeting the high-precision pattern requirements of photovoltaic screen printing plates, demonstrating high process maturity and guaranteed yield.
[0074] In one embodiment, in step S101, the protective film is a laser-permeable polyester film or polyimide film, so that laser engraving can be performed in step S40 without removing the protective film.
[0075] In this embodiment, the protective film, after fulfilling its function of protecting the first surface from chemical etching, does not need to be peeled off during the laser process. This eliminates a film stripping and cleaning step, reducing material waste, equipment investment, and production time, further lowering overall costs and increasing production capacity.
[0076] In one embodiment, the development in step S104 is performed by spray development using a sodium carbonate solution with a concentration of 1.0%-1.5%.
[0077] In this embodiment, a sodium carbonate solution with a concentration of 1.0%-1.5% can better balance the development speed and resolution. While ensuring the complete removal of the dry film that should be exposed, it maximizes the protection of the edge sharpness of the unexposed dry film, thereby obtaining a mask pattern with steeper sidewalls and more accurate dimensions, laying a more solid foundation for the accuracy of subsequent etching.
[0078] In one embodiment, in step S20, the chemical etching solution used to form the semi-etched holes is a ferric chloride solution, and the concentration of free acid in the ferric chloride etching solution is controlled at 1.0% ± 0.2%. Step S20 is performed using a continuous spray etching machine, and the etching temperature is controlled at 40℃ ± 5℃.
[0079] In this embodiment, strict control of free acid concentration and temperature ensures a highly stable and predictable etching rate, enabling precise control of the 6-8 micrometer depth (D1). The use of a continuous spray etching machine in this embodiment allows for continuous substrate feeding and uniform etching, significantly improving the throughput and uniformity of the half-etching process, which aligns perfectly with the overall method's goal of enhancing efficiency.
[0080] In one embodiment, in step S40, the laser is an ultraviolet laser or a picosecond laser, and the spot diameter is 10 micrometers to 30 micrometers.
[0081] In this embodiment, the spot diameter range of 10-30 micrometers meets the accuracy requirements of the photovoltaic screen pattern while ensuring sufficient laser energy density for efficient removal of residual metal. A smaller spot size facilitates fine processing, while appropriately increasing the spot size within this range can slightly improve the single-pulse removal rate and optimize processing speed while maintaining accuracy.
[0082] Figure 3A This is a schematic diagram of the prior art (comparative example) in which only laser etching is used to form etched through holes on a metal substrate. Figure 3B This is a schematic diagram simulating the effect of laser etching to form through-holes on a metal substrate using existing technologies. Figure 3B The H1 marked in the figure represents the thickness of the thinned metal substrate. Figure 3B The text indicates that only laser etching is used to etch a metal substrate with a total thickness of H1=10 micrometers. Figure 4A This is a schematic diagram of forming etched through holes on a metal substrate using the photovoltaic metal mesh fabrication method described in Embodiment 1 of this application. Figure 4B This is a schematic diagram simulating the effect of forming etched through holes on a metal substrate using the photovoltaic metal mesh fabrication method described in this application embodiment. Figure 4B The H1 marked in the figure represents the thickness of the thinned metal substrate. Figure 4B The text indicates that the second surface (surface B) was etched using chemical etching, while the first surface (surface A) was etched using laser etching to achieve a metal substrate with a total thickness of H1 = 12 micrometers. Referring to Table 1 below, it can be seen that the total processing time of the comparative example and Example 1 differs significantly, with the total processing time reduced by approximately 60%.
[0083] Table 1: Simulation experimental parameters and conclusions for the comparative example and Example 1
[0084]
[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A method of making a photovoltaic metal screen, characterized in that, Includes the following steps: S10, a metal substrate with a thickness of H1 is provided, the metal substrate having a first surface and a second surface opposite to each other, a mask layer having a target pattern is formed on the second surface of the metal substrate, the target pattern including a plurality of hole patterns distributed in an effective area and at least two alignment mark patterns located outside the effective area; S20, using the mask layer as protection, chemical etching is performed on the second surface of the metal substrate to form a semi-etched hole of depth D1, while simultaneously etching the alignment mark pattern into an alignment through-hole penetrating the metal substrate; a continuous spray etching machine is used, and the etching temperature is controlled at 40℃±5℃; the chemical etching solution used to form the semi-etched hole is a ferric chloride solution, and the concentration of free acid in the ferric chloride etching solution is controlled at 1.0% ± 0.2%; S30, Remove the mask layer; S40, based on the alignment through-hole, the position of the semi-etched hole is aligned from the first surface of the metal substrate using a visual positioning system, and the bottom of the semi-etched hole is laser-etched to form an etched through-hole penetrating the metal substrate. Step S10 specifically includes: S101, a protective film is applied to the first surface of the metal substrate; the protective film is a laser-permeable polyester film or polyimide film, so that laser engraving can be performed without removing the protective film in step S40. S102, a dry film is pressed onto the second surface of the metal substrate; S103, the dry film is exposed using a film mask containing the target pattern; S104, the exposed dry film is sprayed and developed using a sodium carbonate solution with a concentration of 1.0%-1.5% to remove the dry film in the areas of the hole pattern and the alignment mark pattern, thereby forming the mask layer; The opening size a of the semi-etched hole and the opening size b of the alignment through hole, where a < b; The etching depth of the semi-etched hole is A, and the etching depth of the aligned through hole is B, wherein A < B; and when the difference between ba is 4 micrometers, the difference between BA is 6 micrometers.
2. The method according to claim 1, characterized in that, Step S40, which involves aligning the position of the semi-etched hole from the first surface of the metal substrate using a visual positioning system and laser-etching the bottom of the semi-etched hole to form an etched through-hole penetrating the metal substrate, specifically includes: S401, the image acquisition device of the visual positioning system captures an image containing at least two of the alignment through holes; S402, Process the image and identify the actual pixel coordinates of the center or feature point of each alignment hole; S403, compare the actual pixel coordinates with the preset theoretical coordinates corresponding to the target graphic, and calculate the coordinate transformation parameters or position deviation. S404, according to the coordinate transformation parameters or position deviation, adjust the processing coordinate system of the laser to make the predetermined path of the laser spot coincide with the projection position of the semi-etched hole on the first surface, so as to form an etched through hole penetrating the metal substrate.
3. The method according to claim 2, characterized in that, In step S402, the method for identifying the alignment via feature points includes: extracting the edge of the alignment via using an image processing algorithm, and determining its center coordinates by at least one of geometric center calculation, pattern matching, or crosshair center fitting.
4. The method according to claim 1, characterized in that, In step S40, the laser is an ultraviolet laser or a picosecond laser, and the spot diameter is 10 micrometers to 30 micrometers.
5. The method according to claim 1, characterized in that, The steps preceding step S10 also include: S01, providing a metal substrate with a thickness of H; the thickness of the metal substrate with a thickness of H is between 20 micrometers and 30 micrometers; S02, perform double-sided chemical etching on the metal substrate with thickness H to thin it to a target thickness H1, wherein the target thickness H1 is 10 micrometers to 15 micrometers.
6. The method according to claim 5, characterized in that, The depth D1 is 6 micrometers to 8 micrometers, and the depth of the laser lithography is H1 to D1.