Solar cell printing screen

Abstract

The embodiment of the utility model provides a solar cell printing screen which comprises a gauze layer provided with a plurality of through holes used for allowing slurry to pass through; the adhesive film layer is arranged on the gauze layer; the adhesive film layer is provided with a plurality of adhesive film areas and hollow areas which are alternately arranged, the adhesive film areas are used for blocking slurry, and the hollow areas are used for allowing the slurry to pass through; the adhesive film area comprises a first adhesive film layer and a second adhesive film layer, the first adhesive film layer is arranged on the gauze layer, the second adhesive film layer is arranged on the first adhesive film layer, and the second adhesive film layer partially or completely covers the first adhesive film layer. According to the technical scheme provided by the embodiment of the invention, the thickness of the adhesive film of the printing screen is differentiated, and different electrode structures can be integrally printed by using the same printing screen, so that the welding performance and the low-component performance are considered, the printing time is saved, and the battery quality and efficiency are improved.

Description

Technical Field

[0001] This application relates to the technical field of solar cells, and particularly to a printing stencil for solar cells. Background Art

[0002] A solar cell is a device that converts light energy into electrical energy. To improve the efficiency and stability of solar cells, a grid line structure or other electrode structures, such as main grid lines, sub-grid lines, harpoon structures, centipede foot structures, etc., can be formed on the surface of the solar cell through a printing stencil.

[0003] However, the pattern of the printing stencil is designed according to the type of the electrode structure to be printed. For example: the pattern corresponding to the main grid line structure is designed on the first printing stencil, the pattern corresponding to the sub-grid line structure is designed on the second printing stencil, the harpoon structure is designed on the third printing stencil, and so on. It can be seen that printing needs to be carried out in multiple steps, which takes a long time and consumes a large amount of paste, resulting in low printing efficiency.

[0004] It should be noted that the above content is not necessarily prior art and is not used to limit the patent protection scope of this application. Summary of the Utility Model

[0005] Embodiments of this application provide a printing stencil for solar cells to solve or alleviate one or more of the above technical problems.

[0006] As an aspect of the embodiments of this application, embodiments of this application provide a printing stencil for solar cells, including:

[0007] A mesh layer, provided with a plurality of through holes for the paste to pass through;

[0008] An adhesive film layer, disposed on the mesh layer; the adhesive film layer is provided with a plurality of alternately arranged adhesive film areas and hollow areas, the adhesive film areas are used to block the paste, and the hollow areas are used for the paste to pass through;

[0009] The adhesive film area includes a first adhesive film layer and a second adhesive film layer. The first adhesive film layer is disposed on the mesh layer, the second adhesive film layer is disposed on the first adhesive film layer, and the second adhesive film layer partially or completely covers the first adhesive film layer.

[0010] Optionally, the second adhesive film layer of the adhesive film area completely covers the first adhesive film layer, and the height of the hollow area adjacent to this adhesive film area is equal to the sum of the heights of the first adhesive film layer and the second adhesive film layer. This hollow area is used to form one or more of welding points, main grid lines, and harpoon structures.

[0011] Optionally, the second adhesive film layer in the adhesive film area partially covers the first adhesive film layer, and the height of the hollowed-out area adjacent to the adhesive film area is equal to the height of the first adhesive film area, which is used to form one or more of the main grid line, the sub-grid line, the harpoon structure, the centipede foot structure, and the anti-break grid structure.

[0012] Optionally, the thickness of the mesh layer is 11 - 18 μm.

[0013] Optionally, the thickness of the first adhesive film layer is 4 - 8 μm.

[0014] Optionally, the thickness of the second adhesive film layer is 2 - 4 μm.

[0015] Optionally, the first adhesive film layer includes: a polyimide film, or a graphene / polyimide film.

[0016] Optionally, the second adhesive film layer is an emulsion film.

[0017] Optionally, the solar cell printing screen plate further includes:

[0018] a frame, within which the mesh layer is provided, and the frame includes one or more of aluminum alloy, nickel alloy, copper, polyethylene, polyamide, and polypropylene.

[0019] Optionally, the paste includes one or more of silver, aluminum, and copper.

[0020] The embodiments of the present application adopting the above technical solutions may include the following advantages:

[0021] An adhesive film layer is provided on the mesh layer provided with a plurality of through holes. The adhesive film layer is composed of a plurality of alternately arranged adhesive film areas and hollowed-out areas. The adhesive film area is used to block the paste from flowing to the mesh layer, and the paste can flow to the mesh layer through the hollowed-out area, and then form an electrode structure on the solar cell through the through holes of the mesh layer. The adhesive film area includes a first adhesive film layer and a second adhesive film layer, which are sequentially stacked on the mesh layer. Among them, the second adhesive film layer partially or completely covers the first adhesive film layer. In the case of partial coverage, the height of the hollowed-out area adjacent to the adhesive film area is the same as that of the first adhesive film layer, and the amount of paste that the hollowed-out area can accumulate is less, and the printed electrode structure is thicker. In the case of full coverage, the height of the hollowed-out area adjacent to the adhesive film area is equal to the sum of the heights of the first adhesive film layer and the second adhesive film layer, and the amount of paste that the hollowed-out area can accumulate is more, and the printed electrode structure is thinner. It can be seen that the embodiments of the present application make a differentiated design of the adhesive film thickness of the printing screen plate, and can integrally print electrode structures with different heights / thicknesses using the same printing screen plate, so that the welding points and the main grid line structure have good heights, and the heights of other non-welding electrode structures are lower, thereby taking into account the welding performance and the low-component performance (reducing the paste consumption), saving the printing time, and improving the battery quality and efficiency. Description of the Drawings

[0022] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the several views denote the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in accordance with the present application and should not be regarded as limiting the scope of the present application.

[0023] Figure 1 is a schematic structural view of a solar printing stencil provided by an embodiment of the present application.

[0024] Figure 2 is a schematic cross-sectional view of a solar printing stencil provided by an embodiment of the present application.

[0025] Description of reference numerals:

[0026] 1 Mesh layer

[0027] 2 Adhesive film layer

[0028] 3 Frame

[0029] 4 Welding point

[0030] 5 Main grid line

[0031] 6 Sub-grid line

[0032] 7 Harpoon structure

[0033] 8 Centipede foot structure

[0034] 9 Anti-breaking grid structure

[0035] 21 Adhesive film area

[0036] 22 Hollowed-out area

[0037] 211 First adhesive film layer

[0038] 212 Second adhesive film layer Detailed implementation manners

[0039] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0040] It should be noted that in the description and claims of this application and the above-mentioned drawings, terms such as "first" and "second" are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily limit to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0041] In this application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of optional numerical values within the numerical interval is considered continuous and includes the two numerical endpoints of the numerical interval (i.e., the minimum value and the maximum value), as well as each numerical value between these two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to integers within the numerical interval, it includes the two endpoint integers of the numerical range, as well as each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all sub-ranges subsumed therein. The "numerical values" in the numerical interval can be any quantitative values, such as numbers, percentages, ratios, etc. The "numerical interval" allows for a broad inclusion of quantitative intervals such as percentage intervals, ratio intervals, and ratio value intervals.

[0042] An embodiment of the present application provides a solar cell printing stencil. In this solar cell printing stencil: the film thickness of the stencil in the welding point area and the non-welding point area is designed differently, so that the height of the metal electrode welding points (PAD points) and the main grid (connection) lines welded in the component section is good, and the height of other non-welding areas is lower, taking into account welding performance and low-component performance, saving printing time, improving battery quality, improving the photoelectric conversion efficiency of the battery, and reducing the consumption of silver paste. See the following for details.

[0043] Next, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments described herein.

[0044] As Figures 1-2 shown, the solar cell printing stencil may include a mesh layer 1, an adhesive film layer 2, and a frame 3.

[0045] Next, the structures and cooperation relationships of the mesh layer 1, the adhesive film layer 2, and the frame 3 will be introduced.

[0046] A frame 3 for structural support to reduce the bending or deformation of the screen plate during printing, ensuring printing stability, thereby improving the printing quality and consistency of the electrode structure. The frame 3 may include one or more of aluminum alloy, nickel alloy, copper, polyethylene, polyamide, and polypropylene.

[0047] The mesh layer 1 serves as a substrate, as Figure 1 shown, and can be disposed within the frame 3. Multiple through-holes may be provided in the mesh layer 1 for the paste to penetrate and flow to the surface of the solar cell to form an electrode structure.

[0048] The adhesive film layer 2, as Figure 2 shown, can be disposed on the mesh layer 1. The adhesive film layer 2 may include a plurality of alternately arranged adhesive film regions 21 and hollow regions 22. It should be noted that Figure 2 merely as an example, in practical applications, the number, specific shape, arrangement manner, etc. of the adhesive film regions 21 and the hollow regions 22 can be set according to specific requirements. Among them, the adhesive film region 21 can be used to block the paste from flowing to the mesh layer 1, and the paste cannot penetrate the adhesive film region 21. The hollow region 22 allows the paste to flow through and flow to the mesh layer 1. It can be seen that in the mesh layer 1, the region corresponding to the adhesive film region 21 has no paste passing through, corresponding to the blank region on the surface of the solar cell; the region corresponding to the hollow region 22 allows the paste to flow through, and an electrode structure can be formed on the surface of the solar cell accordingly. Among them, the paste may include one or more of silver, aluminum, and copper.

[0049] The adhesive film region 21 may include a first adhesive film layer 211 and a second adhesive film layer 212. The first adhesive film layer 211 can be disposed on the surface of the mesh layer 1 by means of hot pressing or the like, and the second adhesive film layer 212 can be disposed on the surface of the first adhesive film layer 211 away from the mesh layer 1. As Figure 2 shown, the second adhesive film layer 212 can partially cover the first adhesive film layer 211 or completely cover the first adhesive film layer 211. Combining Figure 2 it can be known that in the case where the second adhesive film layer 212 partially covers the first adhesive film layer 211, the height of the hollow region 22 adjacent to the adhesive film region 21 is the same as that of the first adhesive film layer 211, and the amount of paste that the hollow region 22 can accumulate / circulate is less, and the printed electrode structure is thicker. In the case where the second adhesive film layer 212 completely covers the first adhesive film layer 211, the height of the hollow region 22 adjacent to the adhesive film region 21 is equal to the sum of the heights of the first adhesive film layer 211 and the second adhesive film layer 212, and the amount of paste that the hollow region 22 can accumulate / circulate is more, and the printed electrode structure is thinner.

[0050] In this embodiment, by differentiating the design of the thickness of the adhesive film of the printing screen, different electrode structures can be integrally printed using the same printing screen. For example, the welding points and the main grid line structure have good height, while the height of other non-welding electrode structures is relatively low, thus taking into account the welding performance and the low-component performance (reducing the consumption of the paste), saving the printing time, and improving the battery quality and efficiency.

[0051] The printing screen will be further introduced below.

[0052] In an alternative embodiment, the second adhesive film layer 212 of the adhesive film area 21 completely covers the first adhesive film layer 211. Then, the adjacent hollow area 22 has a large height, and more paste can flow through, which can be used to form one or more electrode structures on the surface of the solar cell, such as the welding point 4, the main grid line 5, and the harpoon structure 7. Among them, the welding point 4 can be used for connecting the solar cells to improve the overall stability of the system. The main grid line 5 can be used to collect the current collected by the sub-grid lines 6 and transmit it to the outside. The harpoon structure 7 can increase the surface area of the electrode, reduce the light shielding, and thus improve the current collection efficiency.

[0053] In this embodiment, through the differentiated design of the screen film thickness, a welding point 4 with good height can be formed, effectively optimizing the welding performance of the solar cell. The main grid line 5 and the harpoon structure 7 with relatively high height can also be set to further improve the photoelectric conversion efficiency of the solar cell.

[0054] In an alternative embodiment, the second adhesive film layer 212 of the adhesive film area 21 partially covers the first adhesive film layer 211. Then, the adjacent hollow area 22 has a large height, and less paste can flow through, which can be used to form one or more electrode structures on the surface of the solar cell, such as the main grid line 5, the sub-grid line 6, the harpoon structure 7, the centipede foot structure 8, and the anti-breakage grid structure 9. Among them, the sub-grid line 6 can be used to collect the current generated by the solar cell. The centipede foot structure 8 can be used to enhance the connection force between the solar cell and the main grid line and improve the stability of the electrode structure. The anti-breakage grid structure 9 can be used to enhance the connection force between the sub-grid lines 6 and prevent breakage.

[0055] In this embodiment, through the differentiated design of the screen film thickness, the main grid line 5, the sub-grid line 6, the harpoon structure 7, the centipede foot structure 8, and the anti-breakage grid structure 9 with relatively low height can be formed, reducing the paste consumption and the printing cost.

[0056] In an alternative embodiment, the thickness of the mesh layer 1 can be 11-18 μm. By controlling the thickness of the mesh layer 1, the paste penetration speed, that is, the printing speed, can be accurately regulated, while ensuring the mechanical strength and durability of the printing screen and improving the service life of the printing screen.

[0057] In an alternative embodiment, the thickness of the first adhesive film layer 211 may be 4-8 μm. By controlling the thickness of the first adhesive film layer 211, it is possible to avoid functional failure due to too low a height of the electrode structure in the non-welding area and increased paste consumption due to too high a height.

[0058] In an alternative embodiment, the thickness of the second adhesive film layer is 2-4 μm. By controlling the thickness of the second adhesive film layer 212, an electrode structure with good height is formed in the welding area, optimizing the welding performance of the solar cell.

[0059] In an alternative embodiment, the first adhesive film layer 211 may include: a polyimide film (PI film), or a graphene / polyimide film. The PI film can act as a barrier layer to prevent the conductive paste from penetrating into unwanted areas, ensuring the clarity and accuracy of the printed pattern. Adding graphene to the PI film can further optimize its chemical stability and ensure the barrier performance.

[0060] In an alternative embodiment, the second adhesive film layer 212 is an emulsion film. An emulsion can be coated on the first adhesive film layer 211 and dried to form an emulsion film. The height of the emulsion film can be freely adjusted, thereby adjusting the height of the hollow area 22 and further adjusting the height of the electrode structure in the welding area of the solar cell.

[0061] Using the solar printing stencil of the embodiment of the present application, a non-differentiated design printing stencil, and multiple printing stencils with separately designed patterns, a single solar cell is printed under the same conditions. The overall silver paste consumption of the solar printing stencil of the embodiment of the present application is 68.5 mg, and the stencil life is 50 W. The overall silver paste consumption of the non-differentiated design printing stencil is 68 mg, and the stencil life is 25 W. The overall silver paste consumption of the multiple printing stencils with separately designed patterns is 70 mg, and the stencil life is 40 W.

[0062] It can be seen that the solar cell printing stencil of the embodiment of the present application takes into account welding performance and low-component performance (reducing paste consumption), saves printing time, and improves battery quality and efficiency.

[0063] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0064] For ease of description, the orientation or positional relationships indicated by orientation terms such as "front, rear, top, bottom, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationships shown in the drawings. This is only for the convenience of describing the present application and simplifying the description. Without contrary explanations, these orientation terms do not indicate or imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present application; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "on top of other devices or structures" will then be positioned as "below other devices or structures" or "beneath other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the relative spatial descriptions used here.

[0065] Unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0066] Unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature can include the direct contact between the first and second features, or can also include the situation where the first and second features are not in direct contact but in contact through additional features between them. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher horizontal level than the second feature. The first feature being "below", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature is at a lower horizontal level than the second feature.

[0067] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0068] It should also be noted that the "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures, or characteristics described in connection with that embodiment being included in at least one embodiment generally described in the present application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure, or characteristic in connection with any embodiment, it is intended that the implementation of such feature, structure, or characteristic in combination with other embodiments also fall within the scope of the present application.

[0069] In the above embodiments, the descriptions of the various embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0070] It should also be noted that the above are only the preferred embodiments of the present application, and do not limit the scope of patent protection of the present application. Any equivalent structural or equivalent process transformation made using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, is similarly included in the scope of patent protection of the present application.

Claims

1. A solar cell printing screen, characterized in that: include: The mesh layer is provided with a plurality of through holes, wherein the through holes are used for the slurry to pass through; A film layer is provided on the mesh layer; the film layer is provided with a plurality of alternately arranged film areas and hollow areas, the film areas are used to block the slurry, and the hollow areas are used to allow the slurry to pass through; The adhesive film area includes a first adhesive film layer and a second adhesive film layer, wherein the first adhesive film layer is arranged on the mesh layer, and the second adhesive film layer is arranged on the first adhesive film layer, and the second adhesive film layer partially or completely covers the first adhesive film layer.

2. The solar cell printing screen according to claim 1, characterized in that: The second film layer in the film area completely covers the first film layer, and the height of the hollow area adjacent to the film area is equal to the sum of the heights of the first film layer and the second film layer. The hollow area is used to form one or more of a welding point, a main grid line, and a harpoon structure.

3. The solar cell printing screen according to claim 1, characterized in that: The second film layer in the film area partially covers the first film layer, and the height of the hollow area adjacent to the film area is equal to the height of the first film layer. The hollow area is used to form one or more of the main grid line, auxiliary grid line, harpoon structure, centipede foot structure, and anti-break grid structure.

4. The solar cell printing screen according to any one of claims 1 to 3, characterized in that: The thickness of the mesh layer is 11-18 μm.

5. The solar cell printing screen according to any one of claims 1 to 3, characterized in that: The thickness of the first adhesive film layer is 4-8 μm.

6. The solar cell printing screen according to any one of claims 1 to 3, characterized in that: The thickness of the second adhesive film layer is 2-4 μm.

7. The solar cell printing screen according to any one of claims 1 to 3, characterized in that: The second adhesive film layer is an emulsion film.

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