Solar cell, screen printing plate and photovoltaic module
By setting a connection section with increased width at the connection position between the grid line and the pad and designing a step structure on the screen, the problem of grid line breakage is solved, the conductive performance of the solar cell is ensured and the cost is reduced.
Patent Information
- Application Number
- CN202422409332.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2034-09-30
AI Technical Summary
In the prior art, the connection between the grid lines and the pads of solar cells is relatively thin and is easily broken during printing and sintering or component welding, thereby affecting the conductive performance.
A connection node is set at the connection position between the gate line and the pad. The width of the connection node is greater than the width of other positions of the gate line and gradually widens in the direction away from the pad. At the same time, a step structure is designed on the screen to form a connection node. The leveling properties of the slurry are used to form the connection node to prevent the gate line from breaking.
It effectively prevents grid line breakage, ensures the conductivity of solar cells, and reduces the amount of paste used by lowering the pad height, thereby reducing costs.
Smart Images
Figure CN223463290U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of solar cells, in particular to a solar cell sheet, a screen and a photovoltaic component. Background Art
[0002] During the production process of solar cells, a screen printing process is required to form a back electrode, a back electric field and a front grid line on the surface of the cell.
[0003] A solar cell consists of a soldering pad, a main grid line, and a thin grid line. The main grid line is connected to the soldering pad, and the thin grid line is perpendicular to the main grid line and electrically connected to the main grid or soldering pad. The soldering pad is the part of the solar cell that can be used to connect to other cells or electrical components, usually on the main grid line of the cell. They are used to conduct and connect current, ensuring that the electricity generated by the cell can be effectively transmitted to the external circuit. The main grid line is part of the metal electrode on the front of the solar cell. Its main function is to collect the photocurrent collected by the thin grid line and transmit it to the wiring outside the cell.
[0004] The applicant has found that the existing technology has at least the following technical problems: In the existing technology, because the connection between the main grid line or fine grid line and the pad is relatively thin, it is easy to break at the connection position during grid line printing and sintering or component welding, affecting the conductive performance of the solar cell. Utility Model Content
[0005] The purpose of the present invention is to provide a solar cell, a screen and a photovoltaic module to solve the technical problem in the prior art that the connection between the grid line and the pad is relatively thin, and the connection position is prone to breakage during grid line printing and sintering or module welding; the many technical effects that can be produced by the preferred technical solution among the many technical solutions provided by the present invention are detailed below.
[0006] To achieve the above objectives, the present invention provides the following technical solutions:
[0007] This embodiment provides a solar cell, including a solder pad and a grid line, wherein:
[0008] A connection node exists at the connection position between the gate line and the pad. The width of the connection node is greater than the width of the remaining positions of the gate line, and each section of the connection node tends to widen in a direction away from the pad.
[0009] Preferably, the gate line comprises a main gate line and a fine gate line, the fine gate line is perpendicular to the main gate line, the connecting node is arranged at the connecting position of the main gate line and the pad, and the width of the connecting node is greater than the width of the remaining positions corresponding to the main gate line; and / or the connecting node is arranged at the connecting position of the fine gate line and the pad, and the width of the connecting node is greater than the width of the remaining positions corresponding to the fine gate line.
[0010] Preferably, when the number of the connecting nodes is two or more, all the connecting nodes are sequentially connected in a head-to-tail mode along the length direction of the corresponding main gate line or fine gate line.
[0011] Preferably, the connecting node comprises a narrow end and a wide end, and the narrow end is connected with the wide end of the pad or another adjacent connecting node.
[0012] Preferably, the length of the connecting node along the extension direction of the corresponding gate line ranges from 0.2 to 1.5 um, and the lengths of the plurality of connecting nodes are equal or unequal.
[0013] Preferably, the height of the connecting node is less than or equal to the height of the remaining positions corresponding to the gate line.
[0014] Preferably, the height of the pad is greater than the height of the connecting node.
[0015] Preferably, the height of the pad is 4.5-9 um; the height difference between the remaining positions of the gate line and the corresponding connecting node is less than or equal to 2 um; and the height difference between the pad and the connecting node is less than or equal to 2 um.
[0016] The utility model also provides a screen for manufacturing the above-mentioned solar cell piece, the screen comprises a screen mesh part and a film layer, wherein:
[0017] The film layer is a non-ink permeable structure, the film layer is fixed to one side of the screen mesh part away from the silicon wafer, and a step structure is formed between the film layer and the screen mesh part in the thickness direction of the screen and / or between adjacent film layers, thereby forming the connecting node.
[0018] Preferably, the film layer comprises at least a first film layer and a second film layer, wherein:
[0019] The first film layer is fixed to one side of the screen mesh part away from the silicon wafer, the first film layer covers opposite sides or the periphery of the screen mesh part, the second film layer is fixed to one side of the first film layer away from the screen mesh part, and the second film layer covers opposite sides or the periphery of the first film layer.
[0020] The second film layer and the first film layer, and / or the first film layer and the screen mesh part form a stepped structure in the thickness direction of the screen printing plate, thereby forming the connecting joint.
[0021] Preferably, the mesh number of the screen mesh part satisfies: distance between adjacent screen wires = (25400 / mesh number of the screen mesh part)-wire diameter.
[0022] Preferably, the mesh number of the screen mesh part is 300-500.
[0023] The utility model also provides a photovoltaic module, including a plurality of above-mentioned solar cell pieces.
[0024] The solar cell piece, the screen printing plate and the photovoltaic module have the beneficial effects that: when the connecting joint is arranged at the connecting position of the grid line and the pad, the width of the connecting joint is greater than the width of the remaining positions of the corresponding grid line, the connecting joint has a widening trend along the direction away from the pad, the grid line breakage is prevented, and the conductivity of the solar cell piece is ensured.
[0025] The screen printing plate has a stepped structure between the second film layer and the first film layer, and / or between the first film layer and the screen mesh part in the thickness direction of the screen printing plate, the slurry overflow phenomenon is caused between the high and low film layers by the leveling characteristics of the slurry, the connecting joint is formed, the solar cell piece is easily manufactured, and the grid line breakage is prevented; and the overall thickness of the film layer and the screen mesh part at the stepped structure is reduced, the height of the pad is reduced, the use amount of the slurry is reduced, and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS
[0026] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.
[0027] Figure 1 It is the structure schematic diagram of the first embodiment of grid line structure;
[0028] Figure 2 It is the structure schematic diagram of the second embodiment of grid line structure;
[0029] Figure 3 It is the schematic diagram of screen printing plate;
[0030] Figure 4 It is the structure schematic diagram of the first embodiment of screen printing plate;
[0031] Figure 5 is a structural schematic diagram of the screen printing plate embodiment two;
[0032] Figure 6 is a sectional structural schematic diagram of the screen printing plate at the step structure;
[0033] Figure 7 is a contrast schematic diagram of the solder pad height when the mesh part thread count is different.
[0034] In the figure, 1 is a solder pad; 2 is a main grid line; 3 is a fine grid line; 4 is a connecting node; 41 is a narrow end; 42 is a wide end; 5 is a mesh part; 51 is a solder pad part; 52 is an antenna part; 53 is a grid line part; 6 is a film layer; 61 is a first film layer; 62 is a second film layer; 7 is a step structure. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical scheme and advantages of the utility model more clear, the technical scheme of the utility model will be described in detail below. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor belong to the scope protected by the utility model.
[0036] In the description of the utility model, it is understood that the orientation or position relationship indicated by the terms "center", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "side" is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as a limitation on the utility model. In the description of the utility model, the meaning of "a plurality of" is two or more, unless otherwise specified.
[0037] In the description of the utility model, it is also necessary to explain that, unless otherwise specified and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For the ordinary skill in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0038] The grid line structure provided by the embodiment of the utility model can prevent the grid line from being broken and ensure the conductive performance of the solar cell piece.
[0039] The following combination Figures 1-7 The technical solution provided by the present invention is described in more detail. The arrow in the figure is the printing direction.
[0040] Embodiment 1:
[0041] The solar cell provided by the present invention includes a solder pad 1 and a grid line. A connection node exists at the connection position between the grid line and the solder pad 1. The width of the connection node is greater than the width of the remaining position of the corresponding grid line; and each connection node gradually widens in the direction away from the solder pad 1.
[0042] Specifically, the gate lines may only include the thin gate lines 3 (without the main gate lines 2 ), and a connection node exists at the connection position between the thin gate lines 3 and the pads 1 .
[0043] Alternatively, the gate line includes a main gate line 2 and a thin gate line 3, and there is a connection node 4 at the connection position of the main gate line 2 and the pad 1, and the width of the connection node 4 is greater than the width of the remaining positions of the corresponding main gate line 2; and / or, there is a connection node 4 at the connection position of the thin gate line 3 and the pad 1, and the width of the connection node 4 is greater than the width of the remaining positions of the corresponding thin gate line 3; and each section of the connection node 4 gradually widens in the direction away from the pad 1.
[0044] See also Figure 1 As shown, Figure 1 The middle main grid line 2 and the thin grid line 3 both have the above-mentioned connection node 4, see Figure 2 As shown, Figure 2 Only the main grid line 2 has the above-mentioned connection node 4. The specific number of the connection node 4 is not limited, and can be one or more than two. Preferably, the number of the connection node 4 is two or more, so as to prevent the main grid line 2 or the thin grid line 3 from breaking.
[0045] In the grid line structure of this embodiment, when a connecting node 4 is set at the connection position between the main grid line 2 and the pad 1, since the width of the connecting node 4 is greater than the width of the remaining positions of the corresponding main grid line 2, the connecting node 4 gradually widens in the direction away from the pad 1, which can prevent the main grid line 2 from breaking. Similarly, when the thin grid line 3 has the above-mentioned connecting node 4, it can prevent the thin grid line 3 from breaking, thereby ensuring the conductive performance of the solar cell.
[0046] It should be noted that the size or shape of the soldering pad 1 shown in the figure does not limit the size or shape of the soldering pad 1 in an actual solar cell. The soldering pad on an actual solar cell can be set according to the performance of the solar cell and the design requirements of the electrode structure.
[0047] As an alternative embodiment, see Figure 1 and Figure 2 As shown, the number of the connection nodes 4 is two or more (including two), and all the connection nodes 4 are connected end to end in sequence along the length direction of the corresponding main grid line 2 or fine grid line 3.
[0048] Referring to Figure 1 and Figure 2 As shown in the drawings, the structure of the connecting section 4 as part of the main grid line 2 or the fine grid line 3 can prevent the main grid line 2 or the fine grid line 3 from being broken under the premise of ensuring the basic functions of the main grid line 2 or the fine grid line 3.
[0049] As an optional embodiment, referring to Figure 1 and Figure 2 The connecting section 4 of the embodiment includes a narrow end 41 and a wide end 42, the narrow end 41 is connected with the pad 1 or the wide end 42 of another adjacent connecting section 4.
[0050] Referring to Figure 1 and Figure 2 The narrow end 41 of one connecting section 4 near the pad 1 is connected with the pad 1, and the wide end 42 thereof is connected with the narrow end 41 of another adjacent connecting section 4, and the structure can prevent the main grid line 2 from being broken and ensure the conductive performance of the grid line structure.
[0051] The length of the connecting section 4 in the embodiment along the extension direction of the corresponding grid line ranges from 0.2 to 1.5 um, and the lengths of the plurality of connecting sections 4 are equal or unequal.
[0052] As an optional embodiment, the height of the connecting section 4 of the embodiment is less than the height of the remaining positions of the corresponding main grid line 2 or fine grid line 3. The height of the pad 1 is greater than the height of the connecting section.
[0053] As an optional embodiment, the height of the remaining positions of the grid line 2 or fine grid line 3 is greater than the height of the pad 1.
[0054] It should be noted that the remaining positions of the main grid line 2 or fine grid line 3 refer to the parts of the grid line other than the connecting sections. For the height of the pad or the grid line mentioned in the utility model, it refers to the vertical height of the center point of the bottom edge of the cross section of the pad or the grid line, which is measured by SEM (scanning electron microscope). The vertical height of the center point of the bottom edge of the cross section of the pad or the grid line at any 20 positions in the test sample is measured, and then the average value is calculated, which is the height of the pad or the grid line. It can also be understood by those skilled in the art that the above method is only exemplary, and those skilled in the art can appropriately reduce or increase the number of selected measurement positions of the copper grid line based on the actual situation.
[0055] Specifically, Figure 3 is a structural schematic view of the screen plate, referring to Figure 3As shown, the screen part 5 includes a pad portion 51, an antenna portion 52 connected with the pad portion, and a grid line portion 53, the paste is infiltrated from the pad portion 51 to form a pad, the paste is infiltrated from the antenna portion 52 to form an antenna, and the paste is infiltrated from the grid line portion 53 to form a main grid line 2. During printing, the conductive paste on the screen is scraped by a squeegee, and the paste is infiltrated from the position of the screen part 5. Due to the leveling property of the paste, the width of the paste is increased at the connection position of the main grid line 2 and the pad 1, and under the premise of a certain total amount of the paste, the width of the paste is increased and the height of the paste is reduced, so that the connection joint is formed.
[0056] It should be noted that, Figure 3 The double-layer structure of the film layer 6 is not shown in the figure.
[0057] As an optional embodiment, the height of the pad 1 is 4.5-9um. For example, the height of the pad can be any one of 4.5um, 5um, 6um, 7um, 8um, and 9um.
[0058] In the grid line structure in the embodiment, the thickness of the metal film at the pad position is reduced due to the design of the double-layer film when the height is reduced, the height of the pad is reduced, the height of the pad can be adaptively reduced, so that the use amount of the paste is reduced and the cost is reduced.
[0059] As an optional embodiment, the height difference between the remaining positions of the grid line and the corresponding connection joint is less than or equal to 2um, and the height difference between the height of the pad and the connection joint is less than or equal to 2um.
[0060] The height difference between the grid line, the pad 1, and the connection joint 4 cannot be too large, so as to prevent problems such as broken solder caused by stress concentration during the soldering process of the solder belt due to the height difference.
[0061] The solar cell provided in the embodiment includes a silicon wafer and the above-mentioned grid line structure, and the grid line structure is located on the silicon wafer.
[0062] The solar cell in the embodiment can prevent the main grid line 2 from being broken, and when the fine grid line 3 has the above-mentioned connection joint 4, the fine grid line 3 can also be prevented from being broken, so as to ensure the conductive performance of the solar cell.
[0063] The utility model further provides a photovoltaic module, including a plurality of above-mentioned solar cell piece.
[0064] Embodiment 2:
[0065] The embodiment provides a screen for manufacturing the above-mentioned solar cell, and the screen includes a screen part 5 and a film layer 6, wherein the film layer 6 is a non-ink permeable structure, the film layer 6 is fixed to one side of the screen part 5 away from the silicon wafer, a step structure 7 is formed between the film layer 6 and the screen part 5 in the thickness direction of the screen, and / or between adjacent film layers 6, so as to form the connection joint 4.
[0066] The film layer 6 is a non-ink permeable structure, and the forming material includes steel, nickel, titanium, alloy steel, nickel alloy or titanium alloy. Specifically, it can be a nickel alloy, which prevents the paste from directly penetrating from the position of the film layer 6 to the silicon wafer. Specifically, during screen printing, the conductive paste on the screen is scraped off by a squeegee, and the paste penetrates from the position of the screen mesh part 5 to fill the paste holes in the non-ink permeable structure (film layer).
[0067] The screen of the embodiment has an increased paste width when printing the pads or the grid lines. Under the premise of a certain total amount of paste, the increased paste width and the reduced height form the connection joints. Therefore, the step structure 7 is at the connection between the connection joint 4 and the pad 1, or the connection between adjacent connection joints. Outside the outermost step structure, the film layer has a uniform height, and the grid line does not have a width change.
[0068] As an optional embodiment, refer to Figure 1 As shown in the figure, the film layer includes at least a first film layer 61 and a second film layer 62, wherein: the first film layer 61 is fixed to the side of the screen mesh part 5 away from the silicon wafer, the first film layer 61 covers the four sides of the screen mesh part 5, the second film layer 62 is fixed to the side of the first film layer 61 away from the screen mesh part 5, and the second film layer 62 covers the four sides of the first film layer 61; the second film layer 62 and the first film layer 61, and / or the first film layer 61 and the screen mesh part 5 form a step structure 7 in the thickness direction of the screen, thereby forming a connection joint 4.
[0069] As shown in the figure, the first film layer 61 and the second film layer 62 of the embodiment have a back-to-back structure. Figure 1 Figure 4 As shown in the figure, the first film layer 61 and the second film layer 62 of the embodiment have a back-to-back structure.
[0070] In the embodiment, on the other hand, the height is determined by the thickness of the screen mesh part 5 and the film layer 6 together, and the thicker the thickness of the film layer 6 and the screen mesh part 5, the thicker the thickness of the printed product. Due to the step structure 7, compared with the technical solution of directly stacking the first film layer 61 and the second film layer 62, the total thickness of the film layer and the screen mesh part 5 at the step structure 7 is reduced, which can reduce the height of the pad, reduce the amount of paste used, and reduce the cost.
[0071] Embodiment 4:
[0072] The difference between the embodiment 4 and the embodiment 3 is that, as shown in the figures, the first film layer 61 covers the opposite sides of the screen mesh part 5, and the second film layer 62 covers the opposite sides of the first film layer 61. Figure 2 Figure 5 As shown in the figure, the first film layer 61 covers the opposite sides of the screen mesh part 5, and the second film layer 62 covers the opposite sides of the first film layer 61.
[0073] As shown in the figure, the first film layer 61 covers the opposite sides of the screen mesh part 5, and the second film layer 62 covers the opposite sides of the first film layer 61. Figure 1 Figure 4 Figure 2 Figure 5 As shown, the film layer 6 of embodiment 4 only covers two sides of the mesh part 5, reducing the possibility of the mesh part 5 hitting the silicon wafer, and facilitating the reduction of the failure rate in the printing process.
[0074] Referring to the table below:
[0075] Table 1: Pad height of different embodiments
[0076] Comment Pad height (pm) BSL 6.5 Example 3 6.1 Example 4 6.2
[0077] Through the above-mentioned embodiments 3 and 4, the corresponding step structure 7 is arranged, the film layer thickness at the corresponding position is reduced at the step structure 7, the height of the product can be reduced, the height of the pad can be reduced, and thus the amount of paste used can be reduced, and the cost can be reduced.
[0078] Embodiment 5:
[0079] In this embodiment, the mesh part 5 needs to meet the following condition: the distance between adjacent mesh wires = (25400 / mesh part 5 mesh count) - wire diameter.
[0080] In this embodiment, the mesh count of the mesh part 5 is reduced by the above-mentioned calculation method, and the height of the pad 1 is reduced.
[0081] As an optional implementation, the mesh count of the mesh part 5 is 300-500.
[0082] Referring to Figure 7 As shown, three gradient differences of 360 mesh, 390 mesh, and 420 mesh are designed, the height difference is solved by changing the mesh count of the screen, and the height of the pad 1 is verified; Figure 7 As shown, the mesh count is changed by changing the distance between the wire diameters, and thus the height is designed, and Figure 7 As can be seen from the above, the smaller the mesh count of the mesh part 5, the lower the height of the pad; similarly, the fish fork, the connecting line, and the antenna can be realized by this technology.
[0083] In this embodiment, the mesh count of the mesh part 5 is reduced by reasonable calculation, the amount of paste leakage is reduced, the height of the pad is reduced, and thus the amount of paste used is reduced, and the cost is reduced.
[0084] Screen making process: mold making (preparing reverse electroforming mold according to printing pattern) → electroforming (first mask) growing first film layer 61 → electroforming (second mask) growing second film layer 62 → film stripping → screen stretching → detection.
[0085] Screen components: mesh part 5, first film layer 61 and second film layer 62; the mesh part 5 includes a mesh body 51, an antenna 52 connected to the mesh body, and a connecting line 53.
[0086] Screen printing process: distributed printing is adopted, back main grid → back fine grid → positive main grid line 2 → positive fine grid line 3.
[0087] Different mesh screen mesh screen part 5 production: according to the different area position different mesh design different pattern → laser engraving into mesh screen.
[0088] In the description of the present specification, a specific feature, structure or characteristic can be combined in any one or more embodiments or examples in a suitable manner.
[0089] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. Furthermore, the skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.
[0090] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A solar cell, characterized by, The grid line and the pad are connected by a connecting node, the width of the connecting node is greater than the width of the rest of the grid line, and each connecting node gradually widens away from the pad. The grid line includes a main grid line and a fine grid line, the fine grid line is perpendicular to the main grid line, the connecting node is arranged at the connecting position of the main grid line and the pad, and the width of the connecting node is greater than the width of the rest of the main grid line; and / or, the connecting node is arranged at the connecting position of the fine grid line and the pad, and the width of the connecting node is greater than the width of the rest of the fine grid line.
2. The solar cell according to claim 1, wherein When the number of connecting nodes is two or more, all the connecting nodes are sequentially connected head to tail along the length direction of the corresponding main grid line or fine grid line.
3. The solar cell according to claim 2, wherein, The connecting node includes a narrow end and a wide end, and the narrow end is connected to the wide end of the pad or another adjacent connecting node.
4. The solar cell of claim 1, wherein, The length of the connecting node along the extension direction of the corresponding grid line ranges from 0.2 to 1.5 um, and the lengths of multiple connecting nodes are equal or unequal.
5. The solar cell of claim 1, wherein, The height of the connecting node is less than or equal to the height of the rest of the corresponding grid line.
6. The solar cell of claim 1, wherein, The height of the pad is greater than the height of the connecting node.
7. The solar cell of claim 1, wherein, The height of the pad is 4.5-9 um.
8. The solar cell of claim 1, wherein, The height difference between the rest of the grid line and the corresponding connecting node is less than or equal to 2 um; and / or, the height difference between the pad and the connecting node is less than or equal to 2 um.
9. The solar cell according to any one of claims 6 to 8, wherein, A screen printing plate for manufacturing a solar cell according to any one of claims 1-9, the screen printing plate comprising a screen mesh portion and a film layer, wherein:
10. A screen, characterized by, The film layer is a non-ink permeable structure, the film layer is fixed to the side of the screen mesh portion away from the silicon wafer, and a step structure is formed between the film layer and the screen mesh portion in the thickness direction of the screen printing plate and / or between adjacent film layers, thereby forming the connecting node. The film layer includes at least a first film layer and a second film layer, wherein:
11. The screen printing screen of claim 10, wherein, The first film layer is fixed to the side of the screen mesh portion away from the silicon wafer, the first film layer covers the opposite sides or the periphery of the screen mesh portion, the second film layer is fixed to the side of the first film layer away from the screen mesh portion, and the second film layer covers the opposite sides or the periphery of the first film layer; A step structure is formed between the second film layer and the first film layer in the thickness direction of the screen printing plate and / or between the first film layer and the screen mesh portion, thereby forming the connecting node. The mesh count of the screen mesh portion satisfies: the distance between adjacent screen wires = (25400 / mesh count of the screen mesh portion) - wire diameter.
12. The screen printing screen of claim 10, wherein, The mesh count of the screen mesh portion is 300-500.
13. The screen printing screen of claim 10, wherein, A plurality of solar cells according to any one of claims 1-9.
14. A photovoltaic module, characterized by