Glue printing screen printing plate and photovoltaic module

Abstract

The embodiment of the invention provides a glue printing screen printing plate and a photovoltaic module, the glue printing screen printing plate comprises a plate body, the plate body is provided with a plurality of glue printing hole groups, and the plurality of glue printing hole groups are distributed on the plate body in an array; each glue printing hole set comprises a first mesh and a second mesh which are arranged in the first direction in a spaced mode. The glue printing hole group is used for printing two glue points distributed at intervals on the battery piece, so that the two ends of the welding strip in the first direction are fixedly connected with the battery piece through the glue points, it is guaranteed that the connection area between the welding strip and the glue point group is large enough, the connection strength of the welding strip and the battery piece is improved, and the stability of the welding strip is improved. Therefore, the reliability of the photovoltaic module is improved, the yield of the photovoltaic module is improved, the output power of the photovoltaic module is improved, and the service life of the photovoltaic module is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic module production, and in particular to a printing offset screen and a photovoltaic module. Background Art

[0002] The welding ribbon in the photovoltaic module is used to connect with the grid line of the battery cell to realize the series and parallel connection between adjacent battery cells, and play the role of collecting and transmitting current. When the welding ribbon is connected to the battery cell without main grid, it is usually necessary to set glue points to improve the connection reliability between the welding ribbon and the battery cell.

[0003] However, the existing glue dot structure has defects. Once the glue dot printing is offset or the solder ribbon placement is offset, the bonding force between the solder ribbon and the glue dot will be reduced, making it impossible for the solder ribbon to be stably fixed on the battery cell. Summary of the invention

[0004] In view of this, the present application provides a printing glue screen and a photovoltaic module, so as to solve the problem in the prior art that the connection between the glue point and the soldering ribbon is not stable enough when the soldering ribbon is offset.

[0005] In a first aspect, an embodiment of the present application provides a printing glue screen, comprising a plate body, on which a plurality of printing glue hole groups are arranged, and the plurality of printing glue hole groups are distributed in an array on the plate body; the printing glue hole groups include first mesh holes and second mesh holes spaced apart along a first direction.

[0006] In a possible implementation manner, along the first direction, a distance L1 between the first mesh and the second mesh satisfies: L1 ≥ 0.2 mm.

[0007] In a possible implementation manner, a size L2 of the first mesh in the first direction satisfies: 0.2 mm ≤ L2 ≤ 0.5 mm; and / or a size L3 of the second mesh in the first direction satisfies: 0.2 mm ≤ L3 ≤ 0.5 mm.

[0008] In a possible implementation, a size L4 of the first mesh in the second direction satisfies: 0.2 mm ≤ L4 ≤ 0.6 mm; and / or a size L5 of the second mesh in the second direction satisfies: 0.2 mm ≤ L5 ≤ 0.6 mm; and the second direction is perpendicular to the first direction.

[0009] In a possible implementation, the glue printing hole group includes a first glue printing hole group, and a plurality of the first glue printing hole groups are spaced apart along a second direction; along the second direction, a distance L6 between two adjacent first glue printing hole groups satisfies: 6mm≤L6≤17mm; and the second direction is perpendicular to the first direction.

[0010] In a possible implementation manner, the glue printing hole group further includes a second glue printing hole group, and along the second direction, the second glue printing hole group is located on one side or both sides of the plurality of first glue printing hole groups.

[0011] In a possible implementation manner, along the second direction, a distance L7 between the second glue printing hole group and an adjacent first glue printing hole group satisfies: 2 mm≤L7≤7 mm.

[0012] In the second aspect, an embodiment of the present application provides a photovoltaic module, including: a battery cell having a secondary grid extending along a first direction; a welding strip extending along a second direction, the welding strip being electrically connected to the secondary grid; a glue point group, including a first glue point and a second glue point spaced apart along the first direction, the glue point group being formed by screen printing of the above-mentioned printing glue; along the first direction, the two ends of the welding strip are respectively bonded and fixed to the battery cell by the first glue point and the second glue point; the first direction and the second direction are perpendicular to each other.

[0013] In a possible implementation, the soldering strip abuts against the auxiliary grid to form an electrical connection; the soldering strip is bonded and fixed to the battery cell through a plurality of the glue point groups spaced apart along the second direction; the number of the glue point groups is 22 to 33.

[0014] In a possible implementation, the welding strip is welded and fixed to the auxiliary grid to form an electrical connection; the welding strip is bonded and fixed to the battery cell through a plurality of the glue point groups spaced apart along the second direction; the number of the glue point groups is 5 to 12.

[0015] In the present application, the printing glue screen is used to print the glue point group, and the first and second glue points can be printed out along the first direction through the first mesh and the second mesh on the printing glue screen, and the two ends of the welding strip along the first direction can be fixedly connected to the battery cell through the first glue point and the second glue point respectively, which improves the bonding effect between the welding strip and the battery cell, thereby improving the reliability of the welding strip, reducing the risk of the welding strip falling off, and is conducive to improving the output power and service life of the photovoltaic module, and the bonding force on the welding strip is relatively uniform, which is conducive to improving the stability of the welding strip. When the printing glue screen provided by the present application is used to print the glue point group, even if the welding strip is offset during placement or the glue point group is offset during printing, it can ensure that there is a sufficiently large connection area between the welding strip and the glue point group, thereby improving the connection strength between the welding strip and the battery cell, improving the stability of the welding strip, and then improving the reliability of the photovoltaic module, which is conducive to improving the yield rate of the photovoltaic module, increasing the output power of the photovoltaic module, and extending the service life of the photovoltaic module.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic diagram of the structure of the photovoltaic module provided for this application;

[0019] Figure 2 for Figure 1 Schematic diagram of the connection structure between the battery cell and the welding ribbon;

[0020] Figure 3 Schematic diagram of the distribution of glue point groups on the battery cell;

[0021] Figure 4 A schematic diagram of the structure of the offset printing screen provided for this application;

[0022] Figure 5 for Figure 4 A schematic diagram of the structure of the printing glue hole group;

[0023] Figure 6 for Figure 4 Magnified view of part A in FIG.

[0024] Reference numerals:

[0025] 100-battery string;

[0026] 200-encapsulation layer;

[0027] 300-cover plate;

[0028] 10-offset printing screen;

[0029] 101-Plate body;

[0030] 20-battery cell;

[0031] 201-auxiliary gate;

[0032] 202-Ontology;

[0033] 30-welding strip;

[0034] 40-Glue dot set;

[0035] 401-first glue point;

[0036] 402-second glue point;

[0037] 1-Printing glue hole group;

[0038] 1a-first printing glue hole group;

[0039] 1b-the second printing glue hole group;

[0040] 11- first mesh;

[0041] 12- Second mesh. DETAILED DESCRIPTION

[0042] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0043] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0044] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0045] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] The present application embodiment provides a photovoltaic assembly, such as Figure 1As shown, the photovoltaic module includes a battery string 100, an encapsulation layer 200 and a cover plate 300. The battery string 100 is composed of a plurality of battery cells 20 connected by a welding ribbon 30. The encapsulation layer 200 is used to cover the surface of the battery string 100, and the cover plate 300 is used to cover the surface of the encapsulation layer 200 away from the battery string 100. The battery cells 20 are electrically connected in the form of a whole piece or multiple pieces to form a plurality of battery strings 100, and the plurality of battery strings 100 are electrically connected in series and / or in parallel. Specifically, the plurality of battery strings 100 can be electrically connected by a welding ribbon 30. The encapsulation layer 200 covers the front and back of the battery cell 20. Specifically, the encapsulation layer 200 can be an organic encapsulation film such as ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene co-elastomer (POE) film, polyethylene terephthalate (PET) film or polyvinyl butyral (PVB). The cover plate 300 may be a glass cover plate, a plastic cover plate or the like having a light-transmitting function, and the surface of the cover plate 300 facing the encapsulation layer 200 may be a concave-convex surface, thereby increasing the utilization rate of the incident light.

[0047] The present embodiment does not limit the types of the battery cell 20, and the types of the battery cell 20 include but are not limited to Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCon), Heterojunction with Intrinsic Thin-film (HJT), Interdigitated Back Contact (IBC), perovskite battery, etc.

[0048] For PERC cells, along the thickness direction, PERC cells include front surface metal silver electrode, front surface silicon nitride passivation layer, phosphorus layer emitter, P-type base silicon layer, local aluminum back field, metal aluminum back electrode, back passivation layer (Al2O3 / SiNx). PERC cells use a passivation film to passivate the back, replacing the full aluminum back field, enhancing the internal back reflection of light in the silicon base, reducing the recombination rate on the back, and increasing the efficiency of the cell by 0.5%-1%.

[0049] For TOPCon cells, along the thickness direction, TOPCon cells include metal silver electrodes, front surface silicon nitride passivation layers, boron-doped emitters, N-type base silicon layers, diffused doping layers, ultra-thin silicon oxide, doped polysilicon, silicon nitride, and metal silver electrodes. The back of the cell is composed of a layer of ultra-thin silicon oxide (1nm to 2nm) and a layer of phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure can block the recombination of minority carrier holes and increase the open circuit voltage and short circuit current of the cell. The ultra-thin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking the recombination of minority carrier holes. The good passivation effect of ultra-thin silicon oxide and heavily doped silicon film causes the energy band on the silicon wafer surface to bend, thereby forming a field passivation effect, greatly increasing the probability of electron tunneling, reducing contact resistance, and increasing the open circuit voltage and short circuit current of the cell, thereby improving the cell conversion efficiency.

[0050] For HJT cells, along the thickness direction, the HJT cells include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0051] For IBC cells, along the thickness direction, IBC cells include silicon nitride anti-layer, N+ front surface field, N-type base silicon layer, P+ emitter, N+ back field, aluminum oxide passivation layer, silicon nitride anti-reflection layer, and metal silver electrode. IBC cells use ion implantation technology to obtain P and N regions with good uniformity and precisely controllable junction depth. There is no grid line blocking on the front of the cell, which can eliminate the shading current loss of the metal electrode and achieve the maximum utilization of incident photons. The short-circuit current can be increased by about 7% compared with conventional solar cells; due to the back contact structure, there is no need to consider the grid line blocking problem, and the grid line ratio can be appropriately widened, thereby reducing the series resistance and having a high fill factor; the surface passivation and surface light trapping structure can be optimized to obtain a lower front surface recombination rate and surface reflection.

[0052] For perovskite cells, along the thickness direction, the perovskite cell includes substrate material, conductive film, electron transport layer (titanium dioxide), perovskite absorption layer (hole transport layer), and metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrode with low loss, so they can generate higher photoelectric voltage and current, making perovskite show higher photoelectric conversion efficiency.

[0053] In this embodiment, the cell 20 is a busbar-free cell, comprising a body 202 and a sub-grid 201 extending along a first direction X and arranged on the surface of the body 202, the sub-grid 201 being used to collect and guide the photocurrent generated in the body 202. A plurality of sub-grids 201 may be arranged at intervals along a second direction Y on the body 202, thereby increasing the current collection path and improving the current collection efficiency. At the same time, it is possible to avoid the situation where the current density of the sub-grid 201 is high, thereby reducing the loss caused by local overheating of the cell 20. When a sub-grid 201 is damaged, the photocurrent may be collected through other sub-grids 201, ensuring that the cell 20 can work normally, thereby improving the stability and service life of the cell 20. The welding strip 30 is fixedly connected to the cell 20 and electrically connected to the fine grid 201 to collect the photocurrent on the fine grid 201. Along the second direction Y, the same welding strip 30 may be electrically connected to a plurality of fine grids 201 respectively, so as to improve the current collection capability of the welding strip 30, thereby improving the output power of the photovoltaic module.

[0054] It should be noted that, in this embodiment, the first direction X and the second direction Y are perpendicular to each other. The first direction X may be specifically the width direction of the welding strip 30 , and the second direction Y may be specifically the length direction of the welding strip.

[0055] like Figure 2 As shown, the welding strip 30 is fixedly connected to the body 202 through the glue point group 40: the glue point group 40 includes a first glue point 401 and a second glue point 402 spaced apart along the first direction X, and the two ends of the welding strip 30 along the first direction X are fixedly connected to the body 202 through the first glue point 401 and the second glue point 402 respectively, thereby improving the bonding effect between the welding strip 30 and the body 202, thereby improving the reliability of the welding strip 30, reducing the risk of the welding strip 30 falling off, and being beneficial to improving the output power and service life of the photovoltaic module, and the bonding force exerted on the welding strip 30 is relatively uniform, which is beneficial to improving the stability of the welding strip 30. In this embodiment, under the condition that the material amount of the glue points remains unchanged, the glue point group 40 is arranged into the first glue point 401 and the second glue point 402 which are distributed at intervals to ensure the tension between the welding ribbon 30 and the glue point group 40: even if the welding ribbon 30 is offset during placement or the glue point group 40 is offset during printing, it can ensure that there is a sufficiently large connection area between the welding ribbon 30 and the glue point group 40, thereby improving the connection strength between the welding ribbon 30 and the battery cell 20, improving the stability of the welding ribbon 30, and then improving the reliability of the photovoltaic module, which is beneficial to improving the yield rate of the photovoltaic module, increasing the output power of the photovoltaic module and extending the service life of the photovoltaic module.

[0056] In this embodiment, the material of the glue point group 40 is insulating glue, which can be epoxy resin glue, acrylic glue, UV curing glue or LED curing glue, etc. The above materials all have good high temperature resistance, corrosion resistance, electrical insulation and weather resistance, and also have high mechanical strength, and can be used for a long time in outdoor environment, which is conducive to improving the service life of photovoltaic modules.

[0057] Moreover, multiple groups of glue point groups 40 can be arranged at intervals along the second direction Y, that is, the same welding strip 30 is bonded and fixed to the body 202 through multiple groups of glue point groups 40, so as to further improve the connection reliability between the welding strip 30 and the battery cell 20. However, the position of the glue point group 40 should be arranged away from the secondary grid 201, so as to prevent the glue point group 40 from affecting the electrical connection effect between the welding strip 30 and the battery cell 20 and causing the output power of the photovoltaic module to be reduced.

[0058] The present application provides two specific implementations for the connection between the battery cell 20, the welding ribbon 30 and the glue point group 40. The two implementations are respectively described in detail below.

[0059] In a first specific embodiment, the soldering strip 30 is fixedly connected to the battery cell 20 through a plurality of glue point groups 40. When the soldering strip 30 is fixed to the body 202 through the glue point groups 40, the bottom surface of the soldering strip 30 can be in close contact with the auxiliary grid 201, so that an electrical connection is formed between the two. The same soldering strip 30 can be fixedly connected to the battery cell 20 through 22 to 33 glue point groups 40 distributed at intervals along the second direction Y. The number of glue point groups 40 can be 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32 or 33, or other values ​​within the above range, which is not limited in this embodiment. If the number of glue point groups 40 is too small (for example, less than 22), the connection stability between the soldering ribbon 30 and the battery cell 20 will be insufficient. If the number of glue point groups 40 is too large (for example, more than 33), the material of the glue point groups 40 will be wasted, and the bonding effect between the soldering ribbon 30 and the battery cell 20 will not be further improved.

[0060] In this embodiment, when preparing a photovoltaic module, the glue dot group 40 is first printed onto the battery cell 20 through the printing screen 10, and then the welding tape 30 is placed on the battery cell 20, so that the welding tape 30 can be bonded and fixed to the body 202 of the battery cell 20 through the first glue dot 401 and the second glue dot 402 on both sides along the first direction X, respectively, and the bottom surface of the welding tape 30 can form a stable electrical connection with the fine grid 201 on the surface of the battery cell 20.

[0061] In the second specific implementation, the welding strip 30 is electrically connected to the fine grid 202 by welding, and the welding strip 30 is bonded and fixed to the body 202 by the glue point group 40, that is, the welding strip 30 is fixedly connected to the battery cell 20 by welding and bonding. The same welding strip 30 can be fixedly connected to the battery cell 20 by 5 to 12 glue point groups 40 distributed at intervals along the second direction Y. The number of the glue point groups 40 can be 5, 6, 7, 8, 9, 10, 11 or 12, or other values ​​within the above range, which is not limited in this embodiment. If the number of the glue point groups 40 is too small (for example, less than 5), the connection stability between the welding strip 30 and the battery cell 20 will be insufficient. If the number of the glue point groups 40 is too large (for example, more than 12), the material of the glue point groups 40 will be wasted, and the bonding effect between the welding strip 30 and the battery cell 20 will not be further improved. That is, compared with the first embodiment, the number of glue point groups 40 in this embodiment can be less, which can further reduce the waste of raw materials while ensuring the connection effect.

[0062] In this embodiment, when preparing a photovoltaic module, the welding tape 30 is first placed on the battery cell 20, so that the bottom surface of the welding tape 30 is welded and fixed to the fine grid 201 on the surface of the battery cell 20 to form an electrical connection, and then the glue point group 40 is printed on the battery cell 20 through the printing screen 10, so that the welding tape 30 can be bonded and fixed to the body 202 of the battery cell 20 on both sides along the first direction X through the first glue point 401 and the second glue point 402 respectively.

[0063] Figure 3 Schematic diagram of the structure when the glue dot group 40 is printed on the body 202 through the printing screen 10. Figure 3 As shown, in any of the above embodiments, two glue point groups 40 with a relatively close distance can be set at the end positions on one side or both sides of the main body 202 along the second direction Y, which can improve the fixing effect of the edge of the battery cell 20 to the welding strip 30.

[0064] The embodiment of the present application further provides a printing glue screen 10 for printing a glue dot group 40. The structure of the printing glue screen 10 is described in detail below.

[0065] like Figure 4As shown, the printing glue screen 10 includes a plate body 101 and an outer frame 102. The plate body 101 is provided with a plurality of printing glue hole groups 1 distributed in an array, and the printing glue hole groups 1 are used to form the glue dot group 40. Specifically, the printing glue hole group 1 includes a first mesh 11 and a second mesh 12 arranged at intervals along the first direction X. When the insulating adhesive material is printed onto the body 202 of the battery cell 20 through the first mesh 11 and the second mesh 12, the first glue point 401 and the second glue point 402 can be formed on the body 202 and spaced apart along the first direction X, so that the two ends of the welding ribbon 30 along the first direction X can be fixedly connected to the body 202 through the first glue point 401 and the second glue point 402 respectively, ensuring the tension between the welding ribbon 30 and the glue point group 40: even if the welding ribbon 30 is offset during placement or the glue point group 40 is offset during printing, it can be ensured that there is a sufficiently large connection area between the welding ribbon 30 and the glue point group 40, thereby improving the connection strength between the welding ribbon 30 and the battery cell 20, improving the stability of the welding ribbon 30, and then improving the reliability of the photovoltaic module, which is beneficial to improving the yield rate of the photovoltaic module, increasing the output power of the photovoltaic module and extending the service life of the photovoltaic module.

[0066] Specifically, Figure 5 As shown, for each printing glue hole group 1, along the first direction X, the distance L1 between the first mesh 11 and the second mesh 12 satisfies: L1 ≥ 0.2mm. L1 can specifically be 0.2mm, 0.23mm, 0.25mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.36mm, 0.4mm, 0.42mm, 0.45mm, 0.48mm or 0.5mm, or other values ​​within the above range, which are not limited in this embodiment. Since the colloid has a certain fluidity, if L1 is too small (for example, less than 0.2mm), the spacing between the first glue dot 401 and the second glue dot 402 printed by the first mesh 11 and the second mesh 12 in the first direction X will be too small, which means that the total length of the glue dot group 40 in the first direction X is too small. If the soldering ribbon 30 is offset when placed or the glue point group 40 is offset when printed, the soldering ribbon 30 will not be able to form a good contact with the glue point group 40, resulting in poor adhesion between the soldering ribbon 30 and the glue point group 40, thereby affecting the connection effect between the soldering ribbon 30 and the battery cell 20.

[0067] Therefore, when the distance L1 between the first mesh 11 and the second mesh 12 satisfies L1 ≥ 0.2 mm, it can ensure that there is a sufficient spacing between the first glue dot 401 and the second glue dot 402 formed by printing, that is, the first glue dot 401 and the second glue dot 402 can be respectively located on both sides of the welding strip 30 along the first direction X, thereby ensuring that both ends of the welding strip 30 along the first direction X can be bonded and fixed to the glue dot group 40. Even if the welding strip 30 is offset when placed or the glue dot group 40 is offset when printed, it can ensure that there is a sufficiently large connection area between the welding strip 30 and the glue dot group 40, thereby improving the stability of the welding strip 30.

[0068] Moreover, in the embodiment where the soldering strip 30 is fixedly connected to the battery cell 20 only through multiple groups of glue point groups 40, when the distance L1 between the first mesh 11 and the second mesh 12 satisfies L1 ≥ 0.2 mm, it can be ensured that the first glue point 401 and the second glue point 402 formed by printing have a sufficient spacing, and the two can be respectively located on both sides of the soldering strip 30 along the first direction X and bonded and fixed to both sides of the soldering strip 30. In this way, the risk of too much insulating glue material flowing to the bottom of the soldering strip 30 due to the first glue point 401 and the second glue point 402 being too close can be reduced, thereby reducing the risk of a gap between the soldering strip 30 and the fine grid 201 and failing to fit closely.

[0069] In a specific embodiment, Figure 5 As shown, the size L2 of the first mesh 11 in the first direction X satisfies: 0.2mm≤L2≤0.5mm, and / or the size L3 of the second mesh 12 in the first direction X satisfies: 0.2mm≤L3≤0.5mm. L2 can be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, or other values ​​within the above range, which is not limited in this embodiment; L3 can be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, or other values ​​within the above range, which is not limited in this embodiment.

[0070] If L2 is too small (e.g., less than 0.2 mm), the size of the printed first glue dot 401 in the first direction X will be too small, and it will not be possible to ensure that a stable bonding effect can be formed between the first glue dot 401 and the soldering strip 30 when the soldering strip 30 is placed offset or the glue dot group 40 is printed offset; if L2 is too large (e.g., greater than 0.5 mm), the size of the printed first glue dot 401 in the first direction X will be too large, which will not only fail to further improve the bonding effect of the first glue dot 401 on the soldering strip 30, but also cause waste of insulating glue materials. Therefore, when the size L2 of the first mesh 11 in the first direction X satisfies: 0.2 mm ≤ L2 ≤ 0.5 mm, the manufacturing cost of the photovoltaic module can be reduced while improving the bonding reliability of the first glue dot 401 and the soldering strip 30.

[0071] Similarly, if L3 is too small (e.g., less than 0.2 mm), the size of the printed second glue dot 402 in the first direction X will be too small, and it will not be possible to ensure that a stable bonding effect can be formed between the second glue dot 402 and the soldering strip 30 when the soldering strip 30 is placed offset or the glue dot group 40 is printed offset; if L3 is too large (e.g., greater than 0.5 mm), the size of the printed second glue dot 402 in the first direction X will be too large, which will not only fail to further improve the bonding effect of the second glue dot 402 on the soldering strip 30, but will also cause waste of insulating glue materials. Therefore, when the size L3 of the second mesh 12 in the first direction X satisfies: 0.2 mm ≤ L3 ≤ 0.5 mm, the manufacturing cost of the photovoltaic module can be reduced while improving the bonding reliability of the second glue dot 402 and the soldering strip 30.

[0072] In a specific embodiment, Figure 5 As shown, the size L4 of the first mesh 11 in the second direction Y satisfies: 0.2mm≤L4≤0.6mm, and / or the size L5 of the second mesh 12 in the second direction Y satisfies: 0.2mm≤L5≤0.6mm. L4 can be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm or 0.6mm, or other values ​​within the above range, which is not limited in this embodiment; L5 can be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm or 0.6mm, or other values ​​within the above range, which is not limited in this embodiment.

[0073] If L4 is too small (e.g., less than 0.2 mm), the size of the printed first glue dot 401 in the second direction Y will be too small, resulting in too small a bonding area between the first glue dot 401 and the soldering strip 30, and reducing the bonding reliability between the first glue dot 401 and the soldering strip 30; if L4 is too large (e.g., greater than 0.6 mm), the size of the printed first glue dot 401 in the second direction Y will be too large, which will not only fail to further improve the bonding effect of the first glue dot 401 on the soldering strip 30, but will also cause waste of insulating glue materials, and may also cause the first glue dot 401 to contact the fine grid 201, thereby reducing the ability of the soldering strip 30 to collect current on the fine grid 201. Therefore, when the size L4 of the first mesh 11 in the second direction Y satisfies: 0.2 mm ≤ L2 ≤ 0.6 mm, the output power of the photovoltaic module can be ensured while improving the bonding reliability between the first glue dot 401 and the soldering strip 30, and the manufacturing cost of the photovoltaic module can also be reduced.

[0074] Similarly, if L5 is too small (e.g., less than 0.2 mm), the size of the printed second glue dot 402 in the second direction Y will be too small, resulting in too small a bonding area between the second glue dot 402 and the soldering strip 30, and reducing the bonding reliability between the second glue dot 402 and the soldering strip 30; if L5 is too large (e.g., greater than 0.6 mm), the size of the printed second glue dot 402 in the second direction Y will be too large, which will not only fail to further improve the bonding effect of the second glue dot 402 on the soldering strip 30, but will also cause waste of insulating glue materials, and may also cause the second glue dot 402 to contact the fine grid 201, thereby reducing the ability of the soldering strip 30 to collect current on the fine grid 201. Therefore, when the size L5 of the second mesh 12 in the second direction Y satisfies: 0.2 mm ≤ L2 ≤ 0.6 mm, the output power of the photovoltaic module can be ensured while improving the bonding reliability between the second glue dot 402 and the soldering strip 30, and the manufacturing cost of the photovoltaic module can also be reduced.

[0075] In a specific embodiment, Figure 4 As shown, along the first direction X, a plurality of rows of glue printing hole groups 1 are arranged on the glue printing screen 10, and each row of glue printing hole groups 1 corresponds to a welding strip 30. Each row of glue printing hole groups 1 includes a plurality of first glue printing hole groups 1a spaced apart along the second direction Y, so that a plurality of glue point groups 40 spaced apart along the second direction Y can be formed on the battery cell 20, and each welding strip 30 can be fixedly connected to the battery cell 20 through the plurality of glue point groups 40, so as to ensure the connection reliability between the welding strip 30 and the battery cell 20. Each first glue printing hole group 1a includes the first mesh 11 and the second mesh 12 described above.

[0076] like Figure 6As shown, along the second direction Y, the distance L6 between two adjacent first glue printing hole groups 1a satisfies: 6mm≤L6≤17mm. L6 can be 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm or 17mm, or other values ​​within the above range, which are not limited in this embodiment. If L6 is too small (for example, less than 6mm), the number of glue point groups 40 corresponding to the same solder strip 30 printed will be insufficient, resulting in insufficient connection stability between the solder strip 30 and the battery cell 20; if L6 is too large (for example, greater than 17mm), the number of glue point groups 40 corresponding to the same solder strip 30 printed will be too large, which will waste the material of the glue point group 40, and the bonding effect between the solder strip 30 and the battery cell 20 will not be further improved. Therefore, when the distance L6 between two adjacent first glue printing hole groups 1a satisfies: 6mm≤L6≤17mm, it can ensure that the number of glue dot groups 40 printed by each row of glue printing hole groups 1 meets the usage requirements, that is, it can ensure that the welding strip 30 and the battery cell 20 have good connection strength without wasting the insulating glue material.

[0077] In this embodiment, the plurality of first glue printing hole groups 1a in the same row may be evenly distributed or unevenly distributed. The number of first glue printing hole groups 1a in each row may be the same or different. Two adjacent rows of first glue printing hole groups 1a along the first direction X may be completely aligned or staggered.

[0078] In a specific embodiment, Figure 4 and Figure 6 As shown, the glue hole group 1 also includes a second glue hole group 1b. Along the second direction Y, the second glue hole group 1b is located on one side or both sides of each row of the plurality of first glue hole groups 1a. Each second glue hole group 1b includes the first mesh 11 and the second mesh 12 described above, that is, the second glue hole group 1b can be the same structure as the first glue hole group 1a. The second glue hole group 1b is used to cooperate with the first glue hole group 1a located at the edge of the battery cell 20 for printing, so as to form two glue point groups 40 with a relatively close distance at the edge of the battery cell 20, so as to improve the fixing effect of the edge of the battery cell 20 to the welding strip 30.

[0079] Specifically, along the second direction Y, the distance L7 between the second glue hole group 1b and the adjacent first glue hole group 1a satisfies: 2mm≤L7≤7mm. L7 can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm or 7mm, or other values ​​within the above range, which are not limited in this embodiment. If L7 is too small (for example, less than 2mm), due to the certain fluidity of the insulating glue material, the distance between the two glue point groups 40 at the edge of the battery cell 20 along the second direction Y will be small or even merged to form a larger and thicker glue point, and the portion of the soldering strip 30 at this location is prone to stress concentration. If L7 is too large (for example, greater than 7mm), the outermost glue point group 40 on the battery cell 20 along the second direction Y is too close to the edge of the battery cell 20, resulting in stress concentration between the portion of the soldering strip 30 close to the end of the battery cell 20 and the edge of the battery cell 20, which affects the service life of the soldering strip 20. Therefore, when the distance L7 between the second glue printing hole group 1b and the adjacent first glue printing hole group 1a satisfies 2mm≤L7≤7mm, it can ensure that two glue point groups 40 with a relatively close distance can be formed at the end position of the battery cell 20 along the second direction Y, and after the welding strip 30 is bonded and fixed to the two glue point groups 40 with a relatively close distance, stress concentration will not occur, which is beneficial to improving the service life of the welding strip 20 and the output power of the photovoltaic module.

[0080] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A printing offset screen, characterized in that: It comprises a plate body (101), on which a plurality of printing glue hole groups (1) are arranged, and the plurality of printing glue hole groups (1) are distributed in an array on the plate body (101); The printing glue hole group (1) comprises a first mesh hole (11) and a second mesh hole (12) which are arranged at intervals along a first direction.

2. The offset printing screen according to claim 1, characterized in that: Along the first direction, a distance L1 between the first mesh (11) and the second mesh (12) satisfies: L1 ≥ 0.2 mm.

3. The offset printing screen according to claim 1, characterized in that: The size L2 of the first mesh (11) in the first direction satisfies: 0.2 mm ≤ L2 ≤ 0.5 mm; And / or, a dimension L3 of the second mesh (12) in the first direction satisfies: 0.2 mm ≤ L3 ≤ 0.5 mm.

4. The offset printing screen according to claim 1, characterized in that: The dimension L4 of the first mesh (11) in the second direction satisfies: 0.2 mm ≤ L4 ≤ 0.6 mm; And / or, a dimension L5 of the second mesh (12) in the second direction satisfies: 0.2 mm ≤ L5 ≤ 0.6 mm; The second direction is perpendicular to the first direction.

5. The offset printing screen according to claim 1, characterized in that: The glue printing hole group (1) comprises a first glue printing hole group (1a), and a plurality of the first glue printing hole groups (1a) are distributed at intervals along the second direction; Along the second direction, a distance L6 between two adjacent first printing glue hole groups (1a) satisfies: 6mm≤L6≤17mm; The second direction is perpendicular to the first direction.

6. The offset printing screen according to claim 5, characterized in that: The glue printing hole group (1) further comprises a second glue printing hole group (1b), and along the second direction, the second glue printing hole group (1b) is located on one side or both sides of the plurality of first glue printing hole groups (1a).

7. The offset printing screen according to claim 6, characterized in that: Along the second direction, a distance L7 between the second glue printing hole group (1b) and the adjacent first glue printing hole group (1a) satisfies: 2mm≤L7≤7mm.

8. A photovoltaic module, characterized in that: include: A battery cell (20) having a secondary grid (201) extending along a first direction; A welding strip (30) extending along the second direction, the welding strip (30) being electrically connected to the auxiliary grid (201); A glue dot group (40), comprising a first glue dot (401) and a second glue dot (402) spaced apart along the first direction, wherein the glue dot group (40) is printed by the printing glue screen (10) according to any one of claims 1 to 7; Along the first direction, two ends of the welding strip (30) are respectively bonded and fixed to the battery cell (20) via the first glue point (401) and the second glue point (402); The first direction and the second direction are perpendicular to each other.

9. The photovoltaic module according to claim 8, characterized in that: The welding strip (30) abuts against the auxiliary grid (201) to form an electrical connection; The welding strip (30) is bonded and fixed to the battery cell (20) via a plurality of the glue point groups (40) distributed at intervals along the second direction; The number of the glue point groups (40) is 22 to 33.

10. The photovoltaic module according to claim 8, characterized in that: The welding strip (30) is welded and fixed to the auxiliary grid (201) to form an electrical connection; The welding strip (30) is bonded and fixed to the battery cell (20) via a plurality of the glue point groups (40) distributed at intervals along the second direction; The number of the glue point groups (40) is 5 to 12.

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