A printing screen

Abstract

The application relates to the technical field of printing screens, in particular to a printing screen. The printing screen comprises a screen body. A plurality of concave-convex structures are distributed on one side of the screen body along the thickness direction of the screen body. The screen body is provided with a printing groove, the printing groove penetrates the screen body along the thickness direction of the screen body, and the width of at least a part of the printing groove is narrowed along the direction away from the concave-convex structures. The printing screen can print a grid line with a relatively narrow width, the slurry ink transfer is more continuous, the slurry ink transfer is more smooth, the printing defects such as grid breakage and virtual printing are less, the printing quality of the grid line is better, and the stability and electrical performance of the solar cell are improved.

Description

Technical Field

[0001] This application relates to the field of printing screen printing technology, and more particularly to a printing screen printing plate. Background Technology

[0002] When printing narrow grid lines on the screen for solar cells, the ink may not flow smoothly, leading to printing defects such as broken grid lines and incomplete printing, which adversely affects the electrical performance and stability of the solar cells. Utility Model Content

[0003] This application discloses a printing screen that can print narrower grid lines while providing better ink continuity, smoother ink flow, and fewer printing defects such as broken grid lines and incomplete printing.

[0004] To achieve the above objectives, embodiments of this application disclose a printing screen, comprising:

[0005] The screen printing body has multiple concave and convex structures distributed on one side along the thickness direction of the screen printing body;

[0006] The screen printing plate body is provided with a printing groove, which extends through the screen printing plate body along the thickness direction, and the width of the printing groove narrows at least partially in the direction away from the concave and convex structure.

[0007] Optionally, multiple of the aforementioned concave and convex structures are regularly distributed on the surface of the screen printing body.

[0008] Optionally, a plurality of the aforementioned concave-convex structures are distributed in a mesh pattern on one side of the screen printing body, and the side of the screen printing body with the aforementioned concave-convex structures is constructed as a mesh surface.

[0009] Optionally, the concave-convex structure is a groove structure, and the portion between two adjacent groove structures is the mesh line of the mesh surface, wherein the wire diameter of the mesh line is 20 micrometers to 30 micrometers; and / or,

[0010] The number of the aforementioned protrusions and dents per inch of length is 300 to 700; and / or,

[0011] Along the thickness direction of the screen body, the depth D of the groove structure is 10 micrometers to 14 micrometers.

[0012] Optionally, the uneven structure is a micrometer-scale structure; and / or,

[0013] The convex-concave structure includes a protruding structure and / or a groove structure; and / or,

[0014] On the surface of the screen body, the shape of the uneven structure is polygonal; and / or,

[0015] The concave-convex structure has at least some of its edges as concave-convex edges.

[0016] Optionally, the widest part of the printing groove and the convex-concave structure are located on the same surface of the screen body.

[0017] Optionally, along the thickness direction of the screen body, the printing groove includes a connected paste buffer section and a paste printing section;

[0018] Wherein, the width of the slurry buffer section is W1, and the width of the narrowest part of the slurry printing section is W2, satisfying the following relationship: W1 > W2.

[0019] Optionally, along the length of the printing tank, the paste printing section has a first printing area and a second printing area connected together, the width of the first printing area is W2, and the width of the widest part of the second printing area is W3, satisfying the following relationship: W3 > W2.

[0020] Optionally, the printing screen further includes a hollowed-out reinforcing structure, which is correspondingly disposed to the second printing area and connected to the screen body.

[0021] Optionally, the reinforcing structure is disposed at one end of the slurry buffer section near the slurry printing section.

[0022] Optionally, the aperture ratio of the first printing area is greater than or equal to 80% and less than or equal to 100%; and / or,

[0023] The aperture ratio of the second printing area is greater than or equal to 30% and less than or equal to 70%; and / or,

[0024] The width W1 of the slurry buffer section is 50μm to 200μm; and / or,

[0025] The width W2 of the first printing area is 3μm to 15μm; and / or,

[0026] The width W3 at the widest point of the second printing area is 10μm to 100μm.

[0027] Optionally, the screen printing body includes a first metal layer and a second metal layer stacked together, the paste printing section penetrates the first metal layer, the paste buffer section penetrates the second metal layer, and a plurality of the concave and convex structures are distributed on the second metal layer.

[0028] Optionally, the printing screen further includes a hollowed-out reinforcing structure, which is provided for a local area of ​​the printing groove along the length of the printing groove.

[0029] Optionally, the reinforcing structure includes a plurality of filaments, and the plurality of filaments are spaced apart along the length direction of the printing groove.

[0030] Optionally, the screen printing plate body includes a first metal layer and a second metal layer stacked together, and the printing groove penetrates through the first metal layer and the second metal layer;

[0031] Along the width direction of the printing groove, the filament extends across the printing groove and both ends of the filament are connected to the second metal layer.

[0032] Compared with the prior art, the beneficial effects of this application are:

[0033] This printing screen features multiple raised and recessed structures on one side of its main body, making this surface rougher and thus improving the adhesion of the ink to the screen. During printing, the ink is less likely to be carried away by the squeegee as it moves. Furthermore, the width of the printing grooves narrows at least partially away from the raised and recessed structures. In other words, the portion of the printing groove closer to the raised and recessed structures is wider, allowing the ink adhering to the screen surface to more easily flow through the wider portion of the printing groove when the squeegee presses the ink, improving the smoothness and continuity of ink flow. The narrower portion of the printing groove further away from the raised and recessed structures helps to reduce the width of the printed collector lines, thereby reducing the wet weight of the ink during line printing.

[0034] During the ink return process, the ink moves with the ink return blade. The uneven structure causes the ink to tumble, which helps to expel air mixed in with the ink and avoids void areas in the ink, thus preventing printing grid breakage caused by void areas.

[0035] In summary, this printing screen can print narrower grid lines while ensuring better and smoother ink flow, thereby reducing printing defects such as grid breaks and incomplete printing. The resulting collector grid lines are narrower and of higher quality, which helps to reduce the cost and improve the efficiency of solar cells. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a perspective view of a printing screen (with a groove structure) disclosed in an embodiment of this application;

[0038] Figure 2This is a top view of a printing screen (with a groove structure) disclosed in an embodiment of this application;

[0039] Figure 3 for Figure 2 The AA cross-section shown in the figure;

[0040] Figure 4 This is a top view of the printing groove disclosed in the embodiments of this application;

[0041] Figure 5 This is a schematic diagram of the structure of the collector grid lines obtained by screen printing as disclosed in the embodiments of this application;

[0042] Figure 6 for Figure 5 The BB cross-section shown in the figure;

[0043] Figure 7 This is a top view of a printing screen (with multiple concave and convex structures distributed in a mesh pattern) disclosed in an embodiment of this application;

[0044] Figure 8A This is a cross-sectional view of a printing screen (with a raised embossed structure) disclosed in an embodiment of this application;

[0045] Figure 8B This is a cross-sectional view of a printing screen (with gradually narrowing printing grooves) disclosed in an embodiment of this application;

[0046] Figure 9 This is a schematic diagram of the concave-convex structure with concave and convex edges disclosed in the embodiments of this application;

[0047] Figure 10 This is a schematic diagram of the substrate disclosed in the embodiments of this application during the fabrication of a first adhesive layer, a first conductive layer, a second adhesive layer, and a reinforcing structure in the fabrication of a filamentary structure.

[0048] Figure 11 This is a schematic diagram of the structure of the substrate disclosed in the embodiments of this application after the third adhesive layer has been fabricated;

[0049] Figure 12 This is a schematic diagram of the structure of the substrate disclosed in the embodiments of this application after the fourth adhesive layer, the second conductive layer and the first metal layer are fabricated in the step of fabricating the screen printing body;

[0050] Figure 13 This is a schematic diagram of the structure of the substrate disclosed in the embodiments of this application after the fifth adhesive layer and the second metal layer are fabricated in the step of fabricating the screen printing body;

[0051] Figure 14 This is a perspective view of a printing screen prepared by the manufacturing method disclosed in the embodiments of this application.

[0052] Explanation of reference numerals in the attached figures:

[0053] 1. Printing screen; 10. Screen body; 11. Embossing structure; 111. Embossing edge; 12. Printing tank; 121. Paste buffer section; 122. Paste printing section; 1221. First printing area; 1222a, 1222b. Second printing area; 13. Screen surface; 131. Screen line; 10a. First metal layer; 10b. Second metal layer; 16. Reinforcing structure; 161. Filament; Z. Thickness direction of the screen body; X. Length direction of the printing tank; Y. Width direction of the printing tank;

[0054] 2. Semi-finished solar cells; 21. Collector grid lines; 211. Main body section; 212a. Overlapping section; 212b. Connecting section;

[0055] 3. Substrate; 31. First adhesive layer; 32. First conductive layer; 33. Second adhesive layer; 34. Third adhesive layer; 35. Fourth adhesive layer; 36. Second conductive layer; 37. Fifth adhesive layer. Detailed Implementation

[0056] 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. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0057] In this application, the terms "upper," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0058] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0059] Furthermore, the terms "set up," "equipped with," "connected," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0060] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0061] One way to improve the cost and efficiency of solar cells is to narrow the width of the current collector grid lines, thereby reducing the wet weight of the paste during printing. This also reduces the overall shading area of ​​the current collector grid lines. Reducing the shading area allows the solar cell to absorb more light, thus improving its conversion efficiency. Reducing the wet weight of the paste also helps to reduce the amount of paste used, thereby lowering the production cost of the solar cell.

[0062] It should be noted that, according to the definition of the width of the collector grid in this field, a linewidth of less than 30 micrometers after sintering, especially less than 20 micrometers, falls within the narrower width range of this application.

[0063] Narrow-width collector grid lines are difficult to print using wire mesh printing because: wire mesh is composed of steel wire mesh and an adhesive layer. When creating the printing grooves on the wire mesh, only the adhesive layer in the grooved area is removed, but the steel wire mesh in the grooved area is retained. This steel wire mesh obstructs the ink flow. When wire mesh is used to print narrow-width collector grid lines, poor ink flow leads to printing abnormalities, resulting in poor flatness of the printed collector grid lines and increased current transmission losses. In other words, wire mesh printing is not suitable for printing narrow-width collector grid lines, which hinders the improvement of conversion efficiency in solar cells by narrowing the linewidth of the collector grid.

[0064] In this application, the term "paste" refers to a carrier for transferring active materials to the surface of a silicon wafer and is a key material for gate line formation. Exemplary examples of pastes include silver paste, silver-aluminum paste, aluminum paste, or silver-coated copper paste.

[0065] Full-aperture printing screens are more suitable for printing narrower collector lines, such as plate stencils, which are screens whose main body is made of metal. Compared to wire mesh screens, plate stencils are used to create printing grooves, for example, by using a mask to block the electrodeposition process, forming the printing groove in the masked area after electrodeposition; or by using laser engraving to remove all material in the grooved area to form the printing groove. In this way, there is almost no material blocking the ink flow in the printing groove of the plate stencil, resulting in better ink shaping and enabling the printing of narrower collector lines with better surface flatness.

[0066] Despite further narrowing of the collector grid width and increases in printing speed, stencil printing still suffers from issues like incomplete grid lines and broken grid lines. The inventors discovered that these problems arise because: In fully open printing screens, such as stencils, the non-printing groove areas are very smooth, resulting in poor adhesion between the ink and the smooth surface. Furthermore, the overall width of the printing groove is also relatively narrow. During printing, the ink, under the pressure of the squeegee and gravity, still faces difficulty entering the narrow printing groove. Due to the poor adhesion between the ink and the non-printing groove areas of the stencil, ink that doesn't enter the printing groove is easily scraped away by the squeegee, causing insufficient ink filling in certain areas of the printing groove. This leads to printing defects such as voids and broken grid lines after printing. During the ink return process, the poor adhesion between the ink and the smooth surface of the non-printing groove areas also easily creates voids in the ink. These voids have little or no ink, further affecting the printing quality of subsequent prints.

[0067] Based on the above analysis, the printing screen of this application embodiment has multiple uneven structures on the surface of the screen body corresponding to the non-printing groove area, making the side of the screen body with the uneven structures rougher, thereby improving the adhesion of the ink to the non-printing groove area of ​​the screen body. Furthermore, at least locally, the width of the printing groove narrows away from the uneven structures. In this way, the printing screen can print narrower grid lines while achieving better and smoother ink flow, thus reducing printing defects such as broken grids and incomplete printing. The printed current collector grid lines are narrower and their flatness is improved, which is beneficial for achieving the industrialization improvement goal of cost reduction and efficiency enhancement in solar cells.

[0068] The technical solution of this utility model will be described below with reference to the embodiments and accompanying drawings.

[0069] Please refer to the following: Figures 1 to 3 This application discloses a printing screen 1, including a screen body 10. Along the thickness direction Z of the screen body, a plurality of concave and convex structures 11 are distributed on one side of the screen body 10.

[0070] The screen body 10 is provided with a printing groove 12. Along the thickness direction Z of the screen body, the printing groove 12 penetrates the screen body 10, and at least part of the width of the printing groove 12 narrows away from the concave and convex structure 11.

[0071] The beneficial effects of the printing screen plate 1 of this application will be explained below.

[0072] The printing screen 1 has multiple raised and recessed structures 11 on the surface of the non-printing groove area of ​​the screen body 10, making the surface of the screen body 10 with raised and recessed structures 11 rougher, thereby improving the adhesion of the ink to the non-printing groove area of ​​the screen body 10. During printing, the ink is less likely to be directly carried away by the squeegee as it moves. Furthermore, at least locally, the width of the printing groove 12 narrows in the direction away from the raised and recessed structures 11. That is, the portion of the printing groove 12 closer to the raised and recessed structures 11 is wider, and when the squeegee squeezes the ink, the ink adhering to the surface of the non-printing groove area of ​​the screen body 10 is more easily inkd through the wider portion of the printing groove 12, which helps improve the smoothness and continuity of ink application. The portion of the printing groove 12 further away from the raised and recessed structures 11 is narrower, which helps to narrow the width of the printed collector lines, thereby reducing the wet weight of the ink during line printing.

[0073] During the ink return process, the ink moves with the ink return blade. The concave-convex structure 11 causes the ink to tumble, which helps to expel air mixed in with the ink and avoids the formation of void areas in the ink. This, in turn, avoids printing defects such as broken grid lines and voids in the grid lines caused by void areas in the ink. The aforementioned void areas in the ink refer to areas on the printing screen 1 with little or no ink.

[0074] In summary, the printing screen 1 can print narrower grid lines while ensuring better and smoother ink flow, thereby reducing printing defects such as grid breaks and incomplete printing. The resulting grid lines are narrower and of higher quality, which is conducive to achieving the industrialization improvement goal of reducing costs and increasing efficiency in solar cells.

[0075] The printing groove of this application will be described in detail below.

[0076] In some embodiments, refer to Figures 1 to 3 The widest part of the printing groove 12 and the concave-convex structure 11 are located on the same surface of the screen body 10.

[0077] As analyzed above, the concave-convex structure 11 can improve the adhesion between the ink and the surface of the screen body 10. The widest part of the printing groove 12 is exactly on the same side as the widest part of the printing groove 12. The ink attached to the screen body 10 can be input through the widest part of the printing groove 12, which is more conducive to ink application and thus improves the printing effect of the collector grid line 21.

[0078] More specifically regarding the narrowing of the printing groove 12, the side of the screen body 10 with the concave-convex structure 11 is the top surface, and the printing groove 12 narrows downwards from the top surface of the screen body 10. (See reference...) Figure 8B The printing groove 12 can narrow gradually, in which case the cross-section of the narrowed portion of the printing groove 12 is trapezoidal. For example... Figure 3As shown, the printing groove 12 can also narrow in a gradient manner, in which case the cross-section of the narrowed portion of the printing groove 12 is stepped. Of course, along the thickness direction Z of the screen body, the printing groove 12 can be narrowed only partially or entirely.

[0079] For ease of understanding, Figures 1 to 3 In this embodiment, the printing screen 1 has one printing groove 12. It is understood that the printing screen can have two, three, four, or other numbers of printing grooves, and this embodiment does not limit this. When there are multiple printing grooves, these grooves can be spaced apart along the width of the printing grooves.

[0080] Furthermore, please refer to the following: Figures 1 to 6 Along the thickness direction Z of the screen body, the printing tank 12 includes a connected paste buffer section 121 and a paste printing section 122.

[0081] The width of the paste buffer section 121 is W1, and the width of the narrowest part of the paste printing section 122 is W2, satisfying the following relationship: W1 > W2.

[0082] In this way, the wider ink buffer section 121 is used to store ink, and the ink buffer section 121 and the embossed structure are located on the same surface of the screen body 10. The ink stored in the ink buffer section 121 can be pressed into the ink printing section 122 when the squeegee is applied, thereby improving the smoothness and continuity of ink application, improving the printing effect of the collector lines 21, and reducing printing defects such as broken lines and incomplete printing. The narrower ink printing section 122 is used to print the main body section 211 of the narrower collector lines 21, thereby reducing the wet weight of the ink and the light-blocking area during the printing of the collector lines 21.

[0083] Furthermore, please refer to the following: Figures 1 to 6 Along the length X of the printing tank, the paste printing section 122 has a first printing area 1221 and a second printing area 1222a, 1222b connected together. The width of the first printing area 1221 is W2. The width of the widest part of the second printing areas 1222a, 1222b is W3, satisfying the following relationship: W3 > W2.

[0084] In this application, the first printing area 1221 is used to print the main body segment 211 of the narrower collector grid line 21. The second printing area 1222a is used to print the overlapping segment 212a of the wider collector grid line 21. The wider overlapping segment 212a can be used to intersect with the busbar and contact the solder ribbon during soldering. The wider overlapping segment 212a allows more electrode material to react with the tin-based alloy of the solder ribbon, thus preventing grid breakage after soldering and improving the pull-out force of the solder ribbon.

[0085] Optionally, the width W1 of the paste buffer section 121 is 50μm to 200μm, for example, 50μm, 100μm, 150μm, or 200μm. When the paste buffer section 121 meets the above width range, the paste can flow smoothly into the paste buffer section 121 and be stored in the paste buffer section 121. When the squeegee presses against the surface of the screen body 10, the squeegee part extends into the paste buffer section 121 within this width range and scrapes away the paste in the paste buffer section 121 to avoid excessive wet weight of the paste during printing. That is to say, the paste printed on the solar cell semi-finished product 2 is mainly the paste in the paste printing section 122. In this application, the solar cell semi-finished product 2 refers to the semi-finished product of the solar cell before the grid lines are made, such as the solar cell semi-finished product 2 after the passivation film coating process is completed.

[0086] Optionally, the width W2 of the first printing area 1221 is 3μm to 15μm, for example, 3μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 12μm, or 15μm. When the width of the first printing area 1221 meets the above-mentioned width range, the first printing area 1221 is wide enough to facilitate the passage of the paste through the first printing area 1221, thereby giving the first printing area 1221 better printing quality. Furthermore, the first printing area 1221 is not excessively wide, thus avoiding problems such as high wet weight of the paste and large light-blocking area of ​​the grid lines caused by excessive width, which is beneficial to achieving cost reduction and efficiency improvement of solar cells.

[0087] Optionally, the width W3 at the widest point of the second printing areas 1222a and 1222b is 10μm to 100μm, for example, 10μm, 50μm, or 100μm. When the width W3 at the widest point of the second printing areas 1222a and 1222b meets the above-mentioned width range, the second printing areas 1222a and 1222b have better ink throughput, thereby improving the printing quality of the area and avoiding the impact on the mechanical strength of the screen body 10 and excessive ink consumption due to excessive width.

[0088] The web version of this application will be described in detail below.

[0089] In some embodiments, refer to Figure 3 The screen printing body 10 includes a first metal layer 10a and a second metal layer 10b stacked together. The paste printing section 122 penetrates the first metal layer 10a, the paste buffer section 121 penetrates the second metal layer 10b, and multiple concave and convex structures 11 are distributed on the second metal layer 10b.

[0090] In other words, the main body 10 of the screen adopts a layered structure, and the layered production method is used to obtain printing sections 122 and ink buffer sections 121 with different inks for the graphic. The concave and convex structure 11 is processed simultaneously on the second metal layer 10b, without the need to add an additional metal layer. This is beneficial for controlling the total thickness of the main body 10 of the screen, and thus controlling the depth of the printing groove 12, so that the depth of the printing groove 12 is shallow, which is conducive to the passage of ink and reduces ink consumption.

[0091] In other words, the stencil body 10 of this application can consist only of a first metal layer 10a and a second metal layer 10b, simplifying the manufacturing process of the stencil body 10. Since the second metal layer 10b can be further electrodeposited on the basis of the first metal layer 10a, the second metal layer 10b and the first metal layer 10a are integrally formed high-strength structures. Of course, the stencil body can also contain other film layers, such as adding an intermediate metal layer between the first metal layer and the second metal layer to improve adhesion.

[0092] More specifically, the first metal layer 10a and the second metal layer 10b can be made of nickel steel. Nickel steel has advantages such as high strength and corrosion resistance.

[0093] Optionally, the thickness of the first metal layer 10a is 5μm to 20μm, for example, 5μm, 10μm, 15μm, or 20μm. When the thickness of the first metal layer 10a meets the above-mentioned thickness range, the first metal layer 10a is thick enough, thus having high structural strength. Furthermore, since the depth of the paste printing section 122 is consistent with the thickness of the first metal layer 10a, meaning the paste printing section 122 also has sufficient depth, the paste fills the paste printing section 122 and is then printed onto the solar cell semi-finished product. The height of the printed grid lines is sufficiently high, thus ensuring that the grid lines have a suitable cross-sectional area to prevent excessive resistance loss in carrier transport on the grid lines. Simultaneously, a smaller light-shielding area can increase the photoelectric conversion efficiency of the solar cell. The first metal layer 10a should not be too thick, to avoid high wet weight of the paste due to excessive thickness, and to prevent reduced flowability of the paste in the narrow printing tank 12.

[0094] Optionally, the thickness of the second metal layer 10b is 5μm to 20μm, for example, 5μm, 10μm, 15μm, or 20μm. When the thickness of the second metal layer 10b meets the above-mentioned thickness range, the second metal layer 10b is sufficiently thick, thereby having high structural strength. Furthermore, the second metal layer 10b is not excessively thick, because the depth of the groove structure is consistent with the thickness of the second metal layer 10b, thus avoiding an excessively deep groove structure and reducing the amount of slurry accumulating in the groove structure.

[0095] Considering that a long printing groove 12 may affect the structural strength of the screen body 10, based on this, if Figure 1 and Figure 2 As shown, in some embodiments, the printing screen 1 further includes a hollowed-out reinforcing structure 16, which is provided for a local area of ​​the printing groove 12 along the length direction X of the printing groove.

[0096] The locally positioned reinforcing structure 16 helps to improve the structural strength of the printing screen 1. Furthermore, along the length X of the printing groove, the ink distribution in areas where the printing groove 12 is offset from the reinforcing structure 16 is not affected by the reinforcing structure 16, and ink distribution in these areas remains relatively smooth. In this way, the length of the printing groove 12 can be extended as much as possible to print continuous, longer collector lines 21.

[0097] Furthermore, referring to the return Figure 1 and Figure 2 The reinforcing structure 16 is correspondingly set with the second printing area 1222a and connected to the screen body 10. Please refer to... Figure 5 and Figure 6 It is understandable that, in order to print a wider overlap section 212a, the opening width of the second printing area 1222a is relatively large, which has a significant impact on the structural strength of the screen body 10. Setting the reinforcing structure 16 corresponding to the second printing area 1222a is beneficial for targeted structural mechanical reinforcement of the screen body 10. On the other hand, the reinforcing structure can also be set corresponding to the second printing area 1222b, thereby allowing for the setting of more reinforcing structures 16, improving the mechanical strength and service life of the printing screen 1. This second printing area 1222b can be used to print the connecting section 212b of the current collector line 21, which is located between two current collector lines.

[0098] Furthermore, the ink flows easily into the wider second printing areas 1222a and 1222b. By placing the reinforcing structure 16 in these wider areas, the ink still achieves good ink flow, and the second printing areas 1222a and 1222b maintain good printing quality. Moreover, the reinforcing structure 16 prevents the doctor blade from penetrating into the wider second printing areas 1222a and 1222b, thus avoiding the doctor blade scraping away the ink.

[0099] Therefore, the first printing area 1221 is offset from the reinforcing structure 16, and the first printing area 1221 is not obstructed by the reinforcing structure 16, allowing the first printing area 1221 to have a high aperture ratio. Specifically, the aperture ratio of the first printing area 1221 is 100%. In another design, to further enhance the structural strength of the printing screen, a reinforcing structure can be added simultaneously to the area corresponding to the first printing area. Depending on the design requirements of the printing screen, the aperture ratio of the first printing area can be set to be greater than or equal to 80% and less than 100%, for example, 80%, 85%, 90%, 95%, 98%, or 99%.

[0100] It should be noted that the aforementioned aperture ratio can be detected using a screen printing inspection instrument. The higher the aperture ratio, the better the ink flow and the better the printing effect of the grid lines. In particular, when the aperture ratio of the first printing area 1221 is 100%, the first printing area 1221 is also called the fully aperture printing area.

[0101] When the narrower first printing area 1221 meets the above-mentioned aperture ratio range, it indicates that there is very little obstruction in the first printing area 1221, the paste has good throughput, and the main body segment 211 of the collector grid line 21 with a narrower width and better shape can be printed.

[0102] Understandably, since the reinforcing structure 16 is correspondingly arranged with the second printing areas 1222a and 1222b, the aperture ratio of the second printing areas 1222a and 1222b is slightly lower than that of the first printing area 1221. Specifically, the aperture ratio of the second printing areas 1222a and 1222b is greater than or equal to 30% and less than or equal to 70%. However, the second printing areas 1222a and 1222b are wider. When the wider second printing areas 1222a and 1222b meet the above aperture ratio range, wider and better-shaped overlapping sections 212a and connecting sections 212b of the collector grid lines 21 can be printed.

[0103] Furthermore, referring to Figure 3 The reinforcing structure 16 is disposed at one end of the slurry buffer section 121 near the slurry printing section 122. In this way, there is no obstruction of the reinforcing structure 16 in the slurry printing section 122, which is conducive to the shaping of the slurry in the slurry printing section 122, improves the flatness of the collector grid line 21, and thus reduces the resistance loss caused by the carrier transport of the collector grid line 21.

[0104] Furthermore, according to the above analysis, when the squeegee presses the screen body 10, the squeegee part extends into the slurry buffer section 121 to scrape away the slurry stored in the slurry buffer section 121. However, the reinforcing structure 16 has a hollow area. Due to the obstruction of the reinforcing structure 16, the squeegee has difficulty scraping away the slurry in the hollow area. As a result, in the second printing area 1222a, the slurry in the hollow area of ​​the reinforcing structure 16 is superimposed on the slurry in the slurry printing section 122. The maximum height of the overlapping section 212a of the current collector line 21 printed in the second printing area 1222a is higher than the height of the main section 211 of the current collector line 21. The overlapping section 212a has more electrode material reacting with the tin-based alloy of the solder ribbon, so as to further reduce the risk of grid breakage during the welding of the overlapping section 212a, and at the same time improve the pull-out force of the solder ribbon.

[0105] Alternatively, the perforated reinforcing structure 16 can be a comb-like structure, a mesh structure, or a honeycomb structure, as long as it can enhance the structural strength of the screen body 10 and allow the paste to pass through.

[0106] For example, refer to the return Figure 1 and Figure 2 The reinforcing structure 16 includes multiple filaments 161, which are spaced apart along the length X of the printing groove to form the comb-like structure described above. The filaments 161 provide good connectivity, thus enhancing the structural strength of the screen body 10. Furthermore, the filaments 161 offer minimal obstruction to the ink, reducing the impact of the reinforcing structure 16 on ink distribution.

[0107] Furthermore, along the width direction Y of the printing groove, the filament 161 traverses the printing groove 12, and both ends of the filament 161 are connected to the second metal layer 10b. In other words, the two ends of the filament 161 are connected to the opposite sidewalls of the printing groove 12. This not only strengthens the structure of the screen body 10 and helps to pull the printing groove 12, but also prevents the printing groove 12 from opening too much when the screen body 10 is under force, making the printed pattern of the printing groove 12 more accurate and improving the printing shape retention effect of the grid lines.

[0108] The concave-convex structure of this application will be described in detail below.

[0109] In some embodiments, please refer to the following: Figures 1 to 4 Multiple concave and convex structures 11 are regularly distributed on the surface of the screen body 10.

[0110] For example, a regular distribution may be an array distribution exhibiting equidistant or mesh-like distribution. These regular distribution methods can make the surface roughness of the non-printing tank area of ​​the screen body 10 more uniform. Correspondingly, the adhesion between the ink and the non-printing tank area surface of the screen body 10 is also roughly the same, resulting in better ink adhesion and ink distribution on the non-printing tank area surface of the screen body 10. This allows the ink to fully fill the printing tank 12, thereby improving the overall printing effect of the collector lines 21.

[0111] Furthermore, the number of raised and recessed structures 11 per inch is between 300 and 700, for example, 300, 500, or 700. When the number of raised and recessed structures 11 per inch meets the above range, the surface roughness of the screen body 10 is relatively high, which improves the adhesion between the ink and the surface of the non-printing groove area of ​​the screen body 10, further enhancing the ink application and printing effect, and reducing ink voids. However, the number of raised and recessed structures 11 should not be excessive, as too many raised and recessed structures 11 are detrimental to improving the surface roughness of the screen body 10.

[0112] In this application, the uneven structure 11 is a micrometer-scale structure. The term "micrometer-scale structure" refers to a microstructure whose length, width, and depth are at the micrometer scale (typically between 1 micrometer and 1000 micrometers). Compared to nanometer-scale structures, micrometer-scale structures can make the surface of the screen body 10 rougher, avoiding nano-effects when the paste is distributed on the nanometer-scale uneven structure of the screen body 10, which would be detrimental to improving the adhesion of the paste to the surface of the non-printing groove area of ​​the screen body 10. Compared to larger structures such as millimeter-scale structures, the surface roughness of the non-printing groove area of ​​the screen body 10 is greatly reduced, which is not conducive to improving the adhesion of the paste to the surface of the non-printing groove area of ​​the screen body 10.

[0113] Furthermore, along the thickness direction Z of the screen printing plate, the depth D of the groove structure is 10 micrometers to 14 micrometers, for example, 10 micrometers, 12 micrometers, or 14 micrometers. The depth of the groove structure meets the above depth range, the groove structure can accommodate an appropriate amount of slurry, and the amount of slurry accumulated in the groove structure is small.

[0114] Optionally, the shape of the uneven structure 11 on the surface of the screen body 10 is polygonal. The polygon can be a triangle, a square, or a regular hexagon, specifically a square with a side length of 10 to 15 micrometers, which is not limited in this embodiment. The polygonal uneven structure 11 has multiple edges, which can effectively enhance the roughness of the surface of the screen body 10, thereby improving the adhesion between the slurry and the surface of the screen body 10.

[0115] Of course, the shape of the concave-convex structure can also be circular, elliptical or irregular.

[0116] Further, see Figure 7 Multiple concave and convex structures 11 are distributed in a mesh on one side of the screen body 10, and the side of the screen body 10 with the concave and convex structures 11 is constructed as the mesh surface 13.

[0117] It is understandable that the various parts of the screen 13 are interconnected, and the screen 13 can evenly distribute the load it bears to each part of the screen 13. Thus, even with the concave and convex structure 11 set, the screen body 10 still has high structural strength, which is beneficial to extending the service life of the printing screen 1.

[0118] Optionally, the concave-convex structure 11 is a groove structure, and the part between two adjacent groove structures is the mesh line 131 of the mesh surface 13. The wire diameter of the mesh line 131 is 20 micrometers to 30 micrometers, for example, 20 micrometers, 25 micrometers or 30 micrometers.

[0119] When the wire diameter of the network cable 131 meets the above-mentioned wire diameter range, the network cable 131 has high structural strength. Therefore, even with the concave-convex structure 11, the main body of the screen 10 still has good structural strength and a long service life.

[0120] Optionally, please refer to the following as well. Figure 3 and Figure 8A The uneven structure 11 includes raised structures and / or groove structures. The groove structure can be masked during electrodeposition of the screen body 10 using an electrodeposition mask corresponding to the groove structure pattern. Then, the remaining portion of the screen body 10, excluding the groove structure, is electrodeposited. This method results in a relatively uniform thickness across all areas of the screen body 10 except for the groove structure, which facilitates the fit between the squeegee and the screen body 10. The raised structure can reduce slurry accumulation.

[0121] Furthermore, referring to Figure 9 The raised and recessed structure 11 has at least some edges that are raised and recessed edges 111, such as serrated edges or wavy edges. The raised and recessed edges 111 make the edges of the raised and recessed structure 11 rougher, which in turn can further increase the roughness of the surface of the screen body 10, which is beneficial to further improve the adhesion between the ink and the screen body 10. As a result, the ink application effect of the ink and the printing effect of the grid lines are better.

[0122] Of course, the edges of a concave-convex structure can also be curved or straight.

[0123] The following is a detailed description of the method for producing the printing screen of this application.

[0124] Please combine further Figures 10 to 14 This application discloses a method for manufacturing a printing screen 1, including the following steps:

[0125] A screen printing plate body 10 is fabricated; wherein, along the thickness direction Z of the screen printing plate body, a plurality of concave and convex structures 11 are fabricated on one side of the screen printing plate body 10; a printing groove 12 is fabricated on the screen printing plate body 10. Along the thickness direction Z of the screen printing plate body, the printing groove 12 penetrates the screen printing plate body 10, and at least in some parts, the width of the printing groove 12 narrows in the direction away from the concave and convex structures 11.

[0126] The printing screen 1 produced by this method has multiple raised and recessed structures 11 distributed on one side of the screen body 10, making the side of the screen body 10 with the raised and recessed structures 11 rougher, thereby improving the adhesion of the ink to the surface of the non-printing groove area of ​​the screen body 10. Furthermore, at least locally, the width of the printing grooves 12 narrows away from the raised and recessed structures. In this way, the printing screen 1 can print narrower grid lines while achieving better and smoother ink flow, thus reducing printing defects such as broken grids and incomplete printing. The resulting current collector grid lines are narrower and of higher quality, which is beneficial for cost reduction and efficiency improvement in solar cells.

[0127] Optionally, before creating the main screen layout, the production method also includes the following steps:

[0128] A reinforcing structure is fabricated; wherein, along the length of the printing groove, the reinforcing structure is provided for a local area of ​​the printing groove 12.

[0129] This manufacturing method employs a step-by-step approach to produce the printing screen 1. Specifically, the reinforcing structure 16 is fabricated first, followed by the screen body 10. The reinforcing structure 16 is fabricated separately, allowing its characteristics to be customized, such as material strength and dimensions. For example, the reinforcing structure 16 can be made of high-strength metal, while the screen body 10 can be made of low-cost metal. In this way, the printing screen 1 produced by this method combines high strength with low cost.

[0130] Specifically, the steps for creating a reinforced structure include the following sub-steps:

[0131] Creating the first adhesive layer: Refer to... Figure 10 (A) A first adhesive layer 31 is formed on a local area of ​​a non-conductive substrate 3;

[0132] Deposition of the first conductive layer: Reference Figure 10 (B) A first conductive layer 32 is deposited on the side of the first adhesive layer 31 opposite to the substrate 3;

[0133] Creating a graphic second adhesive layer: Refer to Figure 10(C) A patterned second adhesive layer 33 is formed on the side of the first conductive layer 32 away from the first adhesive layer 31, so that a local area of ​​the first conductive layer 32 is exposed to the second adhesive layer 33, and the exposed area of ​​the first conductive layer 32 corresponds to the pattern of the reinforcing structure.

[0134] Electrodeposition reinforced structure: Reference Figure 10 (D) A reinforcing structure 16 is electrodeposited on the exposed area of ​​the first conductive layer 32.

[0135] Reference Figure 11 After the step of creating the reinforcing structure, the manufacturing method also includes the following steps:

[0136] Fabricate the third adhesive layer 34: Cover the reinforcing structure 16 with the third adhesive layer 34.

[0137] The substrate 3 is made of materials such as glass, non-conductive resin, or polymer.

[0138] The first adhesive layer 31 is, for example, a UV-curable adhesive (UV adhesive) or other types of non-conductive adhesive, and its thickness is, for example, 2 μm to 15 μm. The first adhesive layer 31 can be fabricated by coating or printing. The first adhesive layer 31 serves to elevate the substrate 3, ensuring that the subsequently fabricated reinforcing structure is at a certain distance from the substrate 3, so that the reinforcing structure can bond with the subsequently fabricated second metal layer 10b.

[0139] The material of the first conductive layer 32 is, for example, a nickel-based alloy or a copper alloy, and the thickness of the first conductive layer 32 can be 10 nm to 15 nm. The deposition method of the first conductive layer 32 is, for example, PVD (Physical Vapor Deposition). The first conductive layer 32 is used to provide a conductive basis for the electrodeposited reinforced structure.

[0140] The second adhesive layer 33 can be a UV-curable adhesive (UV adhesive) or other types of non-conductive adhesive. The second adhesive layer 33 can be fabricated by coating or printing. After the second adhesive layer 33 is printed onto the first conductive layer 32, the pattern of the exposed area of ​​the first conductive layer 32 is identical to the pattern of the reinforcing structure. In this way, the exposed area of ​​the first conductive layer 32 can be used to obtain a reinforcing structure through electrodeposition, for example, electroforming.

[0141] The third adhesive layer 34 can be a UV-curable adhesive (UV adhesive) or other types of non-conductive adhesive. The third adhesive layer 34 can be prepared by coating or printing. The function of the third adhesive layer 34 is to mask the reinforcing structure to prevent the reinforcing structure from continuing to deposit upwards during the fabrication of the screen printing body 10. Specifically, the third adhesive layer 34 also covers the side of the second adhesive layer 33 that faces away from the substrate 3.

[0142] Specifically, please refer to the following: Figure 12 and Figure 13 When the concave-convex structure 11 is a groove structure, the steps for making the screen body 10 include the following sub-steps:

[0143] Preparation of the fourth adhesive layer 35: Refer to Figure 12 (A) A fourth adhesive layer 35 is made on a local area of ​​the substrate 3; wherein the fourth adhesive layer 35 is connected to the third adhesive layer 34, and the pattern after connection corresponds to the pattern of the paste printing section of the printing tank.

[0144] Deposition of the second conductive layer 36: Reference Figure 12 (B) A second conductive layer 36 is deposited in the area of ​​the substrate 3 other than the third adhesive layer 34 and the fourth adhesive layer 35;

[0145] Electrodeposition of the first metal layer 10a: Reference Figure 12 (C) A first metal layer 10a is electrodeposited on the side of the second conductive layer 36 away from the substrate 3; wherein, along the thickness direction of the substrate 3, the side of the first metal layer 10a away from the substrate 3 is located below the bottom surface of the reinforcing structure 16.

[0146] Preparation of the fifth adhesive layer 37: Refer to Figure 13 (A) A fifth adhesive layer 37 is formed on a local area of ​​the first metal layer 10a. The pattern of the fifth adhesive layer 37 corresponds to the pattern of the paste buffer section of the printing tank and the pattern of the groove structure.

[0147] Fabrication of the second metal layer 10b: Refer to Figure 13 (B) A second metal layer 10b is formed on the exposed area of ​​the first metal layer 10a so that the reinforcing structure 16 connects to the second metal layer 10b, thereby obtaining the screen body 10. The second metal layer 10b has a paste buffer section and a groove structure formed thereon.

[0148] The fourth adhesive layer 35 can be a UV-curable adhesive (UV adhesive) or other types of non-conductive adhesive. The fourth adhesive layer 35 can be fabricated by coating or printing. The thickness of the fourth adhesive layer 35 is, for example, 3μm to 15μm. The function of the fourth adhesive layer 35 is to bond with the third adhesive layer 34, and the resulting pattern corresponds to the pattern of the paste printing section 122 of the printing tank 12. In this way, during subsequent metal deposition, no metal will be deposited on the surfaces of the fourth adhesive layer 35 and the third adhesive layer 34, thus forming the paste printing section 122.

[0149] The material of the second conductive layer 36 is, for example, a nickel-based alloy or a copper alloy, and the thickness of the second conductive layer 36 can be 10 nm to 15 nm. The first conductive layer 32 is deposited by, for example, PVD (Physical Vapor Deposition). The second conductive layer 36 is used to provide a conductive base for the electrodeposited first metal layer 10a.

[0150] The electrodeposition method of the first metal layer 10a is, for example, electroplating.

[0151] The fifth adhesive layer 37 can be a UV-curable adhesive (UV adhesive) or other types of non-conductive adhesive. The fifth adhesive layer 37 can be fabricated by coating or printing. During subsequent metal deposition, no metal will be deposited on the surface of the fifth adhesive layer 37, thus forming a paste buffer section and groove structure.

[0152] The electrodeposition method of the second metal layer 10b is, for example, electroplating. It is understood that during the electrodeposition of the second metal layer 10b, when the metal is deposited to the same height as the reinforcing structure, the reinforcing structure can bond with the deposited metal, and the resulting second metal layer 10b is integrated with the reinforcing structure.

[0153] Furthermore, after the step of creating the main screen template 10, the production method also includes the following steps:

[0154] Separate the screen printing plate body 10: Separate the screen printing plate body 10 from the substrate 3;

[0155] Glue removal: Remove the first glue layer 31, the second glue layer 33, the third glue layer 34, the fourth glue layer 35 and the fifth glue layer 37 from the screen body 10;

[0156] Remove the first conductive layer 32.

[0157] One method for separating the screen printing plate body 10 is to peel the screen printing plate body 10 from the substrate 3.

[0158] The adhesive removal method includes, for example, using an adhesive remover to dissolve and remove the first adhesive layer 31, the second adhesive layer 33, the third adhesive layer 34, the fourth adhesive layer 35, and the fifth adhesive layer 37. The appropriate type of adhesive remover can be selected based on the material of the adhesive layers; details will not be elaborated here.

[0159] The first conductive layer 32 can be removed by methods such as heat treatment and ultrasonic cleaning. Since the first conductive layer 32 is relatively thin, with a thickness of only 10nm to 15nm, while the first metal layer 10a and the second metal layer 10b have thicknesses of 5μm to 20μm, which are much greater than the thickness of the first conductive layer 32, removing the thinner first conductive layer 32 will not significantly affect the thicker first metal layer 10a and the second metal layer 10b. Furthermore, the second conductive layer 36 can be removed simultaneously during the removal of the first conductive layer 32.

[0160] More specifically, when the concave-convex structure is a raised structure, the steps for manufacturing the screen printing plate body include the following sub-steps: the above-mentioned manufacturing of the fourth adhesive layer, the above-mentioned deposition of the second conductive layer, and the above-mentioned electrodeposition of the first metal layer also include the following sub-steps:

[0161] Creating the sixth adhesive layer: A sixth adhesive layer is created on a local area of ​​the first metal layer, and the pattern of the sixth adhesive layer corresponds to the pattern of the paste buffer section of the printing tank;

[0162] Fabrication of a second metal layer: A second metal layer is fabricated on the exposed area of ​​the first metal layer so that the reinforcing structure connects to the second metal layer, thus obtaining the screen body; wherein, a paste buffer section is formed on the second metal layer.

[0163] Creating the seventh adhesive layer: Create a hollowed-out seventh adhesive layer on the side of the second metal layer that faces away from the first metal layer. The pattern of the hollowed-out area of ​​the seventh adhesive layer corresponds to the pattern of the raised structure.

[0164] Fabrication of raised structures: Electrodeposition is performed on the hollowed-out area of ​​the seventh adhesive layer to create raised structures on the surface of the second metal layer.

[0165] In this embodiment, a screen printing plate with an uneven structure is prepared using an electrodeposition process. Of course, the uneven structure can also be created by laser engraving, chemical etching, or other methods; this embodiment does not limit the application to these methods.

[0166] 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 printing screen, characterized in that, include: The screen printing body has multiple concave and convex structures distributed on one side along the thickness direction of the screen printing body; The screen printing plate body is provided with a printing groove, which extends through the screen printing plate body along the thickness direction, and the width of the printing groove narrows at least partially in the direction away from the concave and convex structure.

2. The printing screen according to claim 1, characterized in that, Multiple of the aforementioned concave and convex structures are regularly distributed on the surface of the screen printing body.

3. The printing screen according to claim 2, characterized in that, Multiple concave-convex structures are distributed in a mesh pattern on one side of the screen printing body, and the side of the screen printing body with the concave-convex structures is constructed as a mesh surface.

4. The printing screen according to claim 3, characterized in that, The concave-convex structure is a groove structure, and the portion between two adjacent groove structures is the mesh line of the mesh surface, the wire diameter of the mesh line being 20 micrometers to 30 micrometers; and / or, The number of the aforementioned protrusions and dents per inch of length is 300 to 700; and / or, Along the thickness direction of the screen body, the depth D of the groove structure is 10 micrometers to 14 micrometers.

5. The printing screen according to claim 1, characterized in that, The uneven structure is a micron-scale structure; and / or The convex-concave structure includes a protruding structure and / or a groove structure; and / or, On the surface of the screen body, the shape of the uneven structure is polygonal; and / or, The concave-convex structure has at least some of its edges as concave-convex edges.

6. The printing screen according to any one of claims 1 to 5, characterized in that, The widest part of the printing groove and the concave-convex structure are located on the same surface of the screen body.

7. The printing screen according to any one of claims 1 to 5, characterized in that, Along the thickness direction of the screen body, the printing groove includes a connected paste buffer section and a paste printing section; Wherein, the width of the slurry buffer section is W1, and the width of the narrowest part of the slurry printing section is W2, satisfying the following relationship: W1 > W2.

8. The printing screen according to claim 7, characterized in that, Along the length of the printing groove, the paste printing section has a first printing area and a second printing area connected together. The width of the first printing area is W2, and the width of the widest part of the second printing area is W3, satisfying the following relationship: W3 > W2.

9. The printing screen according to claim 8, characterized in that, The printing screen also includes a hollowed-out reinforcing structure, which is correspondingly arranged with the second printing area and connected to the screen body.

10. The printing screen according to claim 9, characterized in that, The reinforcing structure is located at one end of the slurry buffer section near the slurry printing section.

11. The printing screen according to claim 8, characterized in that, The aperture ratio of the first printing area is greater than or equal to 80% and less than or equal to 100%; and / or, The aperture ratio of the second printing area is greater than or equal to 30% and less than or equal to 70%; and / or, The width W1 of the slurry buffer section is 50μm to 200μm; and / or, The width W2 of the first printing area is 3μm to 15μm; and / or, The width W3 at the widest point of the second printing area is 10μm to 100μm.

12. The printing screen according to claim 7, characterized in that, The screen printing body includes a first metal layer and a second metal layer stacked together. The paste printing section penetrates the first metal layer, the paste buffer section penetrates the second metal layer, and a plurality of the concave and convex structures are distributed on the second metal layer.

13. The printing screen according to any one of claims 1 to 5, characterized in that, The printing screen also includes a hollowed-out reinforcing structure, which is provided for a local area of ​​the printing groove along the length of the printing groove.

14. The printing screen according to claim 13, characterized in that, The reinforcing structure includes a plurality of filaments, and the plurality of filaments are spaced apart along the length direction of the printing groove.

15. The printing screen according to claim 14, characterized in that, The screen printing body includes a first metal layer and a second metal layer stacked together, and the printing groove passes through the first metal layer and the second metal layer; Along the width direction of the printing groove, the filament extends across the printing groove and both ends of the filament are connected to the second metal layer.

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