Screen printing plate structure for manufacturing solar cell and coating device
By setting mesh areas of different mesh sizes in the screen structure and controlling the difference in photoresist thickness, the problem of uneven copper grid height is solved, and efficient preparation of solar cells and material savings are achieved.
Patent Information
- Application Number
- CN202422782514.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-11-14
AI Technical Summary
In the process of manufacturing solar cells, the uneven height of copper grid lines in the existing technology leads to the appearance of "mushroom-shaped" grid lines, which increases the shading area, reduces electrical performance and wastes materials.
The mesh numbers of the first and second areas of the screen structure are different. The first area is arranged corresponding to the central area of the battery cell, and the second area is arranged corresponding to the peripheral area. This controls the difference in photoresist thickness, prevents "mushroom-shaped" grid lines, and saves materials.
It effectively prevents plating on the edge of copper grid line during electroplating, improves electrical performance, reduces material waste and reduces costs.
Smart Images
Figure CN223333275U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of photovoltaic technology, and in particular to a screen structure and a coating device for manufacturing solar cells. Background Art
[0002] With the development of photovoltaic technology, in the preparation process of solar cells, such as heterojunction solar cells, it is usually necessary to coat photoresist on the copper seed layer, and the photoresist covers the copper seed layer with a thickness of 10um to 14um; then the photoresist is exposed and developed, that is, the unexposed photoresist is removed to expose the copper seed layer; then the electroplating process is entered, and copper grid lines and tin grid lines are prepared in sequence by electroplating on the exposed copper seed layer; finally, the film stripping and back etching step is entered, that is, the excess photoresist and copper seed layer not covered by the copper grid lines are removed, thereby preparing the electrode.
[0003] In the related art, a screen structure with uniform mesh count in each area is usually used to apply photoresist, that is, the thickness of the photoresist in each area on the copper seed layer is consistent. In the process of preparing the copper grid line, the height of the copper grid line in the center of the cell is the ideal height and the same as the thickness of the photoresist. However, the height of the copper grid line is affected by the current difference, resulting in the height of the copper grid line around the cell being too high. The copper grid line is too high and exceeds the thickness of the applied photoresist. The part that exceeds the photoresist is no longer bound by the photoresist and spreads to both sides, causing the following problems: Figure 1 The "mushroom-shaped" gate lines shown in the figure are wider than conventional gate lines, increasing the light shielding area. This type of gate line has a low Isc in electrical performance data, resulting in low efficiency.
[0004] In order to prevent the appearance of "mushroom-shaped" grid lines, a lower mesh number, such as 80 mesh, is used to apply photoresist, and the overall photoresist thickness of the cell is increased to Figure 2 The high film thickness effect shown is to restrain the copper grid line from plating. However, after the overall thickness of the photoresist of the cell is increased, the thickness of the photoresist material in the central area is significantly greater than the height of the copper grid line, as shown in FIG. Figure 3 As shown, resulting in a lot of material waste. Summary of the Invention
[0005] Based on this, it is necessary to overcome the defects of the existing technology and provide a screen structure and a coating device for manufacturing solar cells, which can avoid the appearance of "mushroom-shaped" grid lines and save material costs.
[0006] A screen structure for manufacturing a solar cell, the screen structure for manufacturing a solar cell comprising:
[0007] A mesh body having a plurality of mesh holes, wherein the mesh body is provided with a first area and a second area, wherein the second area is arranged on the periphery of the first area, and the mesh number of the mesh holes in the first area is greater than the mesh number of the mesh holes in the second area; the first area is arranged to correspond to the central area position of the battery cell so that the photoresist can be applied to the central area of the battery cell; the second area is arranged to correspond to the peripheral area position of the battery cell so that the photoresist can be applied to the peripheral area of the battery cell.
[0008] In one embodiment, the second region is disposed circumferentially around the first region.
[0009] In one embodiment, the ratio of the mesh number of the first zone to the mesh number of the second zone is 1.3 to 1.7.
[0010] In one embodiment, the mesh size of the first zone is 110 to 130; the mesh size of the second zone is 70 to 90.
[0011] In one embodiment, the outer contour of the first area is configured to be rectangular, circular, or elliptical; and the outer contour of the second area is configured to be rectangular, circular, or elliptical.
[0012] In one embodiment, the mesh body is further provided with at least one third zone located between the first zone and the second zone, the mesh number of the mesh in the third zone is greater than the mesh number of the mesh in the second zone, and the mesh number of the mesh in the third zone is smaller than the mesh number of the mesh in the first zone.
[0013] In one embodiment, the meshes are circular, elliptical or polygonal; the meshes in the first zone are arranged in an array, and the meshes in the second zone are arranged in an array.
[0014] In one embodiment, the screen structure further includes a frame arranged circumferentially around the screen body, and the frame is connected to the screen body.
[0015] In one embodiment, the mesh body is made of non-metallic material; and the frame is made of metallic material.
[0016] A coating device comprises the screen structure for manufacturing solar cells.
[0017] The above-mentioned screen structure and coating device for making solar cells, during the process of coating the photoresist onto the cell, the screen body and the cell are aligned so that the first area is arranged corresponding to the central area of the cell, and the second area is arranged corresponding to the peripheral area of the cell, and the photoresist is coated on the central area and peripheral area of the cell respectively. Among them, the mesh number of the mesh in the first area is greater than the mesh number of the mesh in the second area, and the thickness of the photoresist in different areas is controlled by the rule that low mesh number has large ink transmittance and high mesh number has small ink transmittance. In this way, the thickness of the photoresist coated on the central area of the battery cell is less than the thickness of the photoresist in the peripheral area, so that the thickness of the photoresist in the peripheral area of the battery cell is larger, which can prevent the battery cell from having "mushroom-shaped" grid line defects in the step of electroplating copper grid lines, that is, improve the problem of low efficiency caused by plating at the edge of the battery cell during electroplating; at the same time, the thickness of the photoresist in the central area of the battery cell is smaller, and the specific size is consistent with the thickness of the copper grid lines electroplated on the battery cell. In this way, there is no need to design the thickness of the photoresist in the central area of the battery cell to be the same as the thickness of the photoresist in the peripheral area, thereby reducing unnecessary materials, avoiding material waste, and greatly saving costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a structural diagram of the copper grid lines around the battery cell in the related art.
[0019] Figure 2 This is a structural diagram of the copper grid lines around the battery cell after coating the battery cell with a low-mesh screen structure in the related art.
[0020] Figure 3 This is a structural diagram of the copper grid lines in the central area of a solar cell after coating the solar cell using a low-mesh screen structure in the related art.
[0021] Figure 4 This is a structural diagram of a screen structure for manufacturing solar cells according to an embodiment of the present application.
[0022] Figure 5 This is a structural diagram of a screen structure for manufacturing solar cells according to another embodiment of the present application.
[0023] Figure 6 This is a structural diagram of a screen structure for manufacturing solar cells according to another embodiment of the present application.
[0024] 10. Grid body; 101. Mesh; 11. First area; 12. Second area; 13. Third area; 20. Frame. DETAILED DESCRIPTION
[0025] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.
[0026] It should be noted that the mesh number in this embodiment refers to the particle size or coarseness of the material. It is generally defined as the number of mesh holes within an area of 1 inch x 1 inch, that is, the number of mesh holes in the screen. The mesh number at which the material can pass through is defined as the mesh number. For example, 200 mesh means that the material can pass through a screen with 200 mesh holes within an area of 1 inch x 1 inch. Similarly, the larger the mesh number, the smaller the mesh hole size, and the smaller the mesh number, the larger the mesh hole size.
[0027] See Figure 4 , Figure 4 A structural diagram of a screen structure for manufacturing solar cells according to an embodiment of the present application is shown. An embodiment of the present application provides a screen structure for manufacturing solar cells, and the screen structure for manufacturing solar cells includes: a screen body 10, the screen body 10 is formed with a plurality of mesh holes 101, and the screen body 10 is provided with a first area 11 and a second area 12. The second area 12 is arranged at the periphery of the first area 11, and the mesh number of the mesh holes 101 of the first area 11 is greater than the mesh number of the mesh holes 101 of the second area 12. The first area 11 is arranged to correspond to the central area position of the battery cell so that the photoresist can be applied to the central area of the battery cell. The second area 12 is arranged to correspond to the peripheral area position of the battery cell so that the photoresist can be applied to the peripheral area of the battery cell.
[0028] It should be noted that the first region 11 being arranged in correspondence with the central region of the cell means that the projection of the first region 11 on the cell in a direction perpendicular to the surface of the cell at least partially overlaps with the central region of the cell. The second region 12 being arranged in correspondence with the peripheral region of the cell is similar and will not be further described here.
[0029] The above-mentioned screen structure for making solar cells, during the process of coating the photoresist onto the cell, the screen body 10 is aligned with the cell so that the first area 11 is arranged corresponding to the central area of the cell, and the second area 12 is arranged corresponding to the peripheral area of the cell, and the photoresist is coated on the central area and peripheral area of the cell respectively. Among them, the mesh number of the mesh 101 of the first area 11 is greater than the mesh number of the mesh 101 of the second area 12. The thickness of the photoresist in different areas is controlled by the rule that low mesh number has a large ink transmittance and high mesh number has a small ink transmittance. In this way, the thickness of the photoresist coated on the central area of the battery cell is less than the thickness of the photoresist in the peripheral area, so that the thickness of the photoresist in the peripheral area of the battery cell is larger, which can prevent the battery cell from having "mushroom-shaped" grid line defects in the step of electroplating copper grid lines, that is, improve the problem of low efficiency caused by plating at the edge of the battery cell during electroplating; at the same time, the thickness of the photoresist in the central area of the battery cell is smaller, and the specific size is consistent with the thickness of the copper grid lines electroplated on the battery cell. In this way, there is no need to design the thickness of the photoresist in the central area of the battery cell to be the same as the thickness of the photoresist in the peripheral area, thereby reducing unnecessary materials, avoiding material waste, and greatly saving costs.
[0030] After the cell is coated using a screen structure, the thickness of the photoresist in the central area of the cell is thinner than that in the peripheral areas. The photoresist is then exposed and developed, or patterned, to remove the unexposed photoresist, exposing the copper seed layer. The electroplating process then proceeds to sequentially deposit copper and tin grid lines on the exposed copper seed layer. Finally, the stripping and etching step removes the excess photoresist and copper seed layer not covered by the copper grid lines, thereby producing the electrode.
[0031] In one embodiment, the second region 12 is arranged circumferentially around the first region 11. Specifically, the first region 11 is arranged in the center of the mesh body 10, and the second region 12 is arranged in the peripheral region of the mesh body 10. In this way, after the photoresist is coated on the cell using the mesh structure, the film thickness is high in the peripheral regions of the cell and low in the central region. This reduces the amount of photoresist material in the central region, saving costs. At the same time, the photoresist thickness in the peripheral regions is thicker, meeting process requirements.
[0032] In some embodiments, the second area 12 can be configured as a closed ring or a non-closed ring. It should be noted that the closed ring means, for example, selecting any point of the second area 12 as the starting point, and moving one circle along the extension direction of the second area 12 from the starting point can return to the starting point. Conversely, the non-closed ring means, for example, selecting any point of the second area 12 as the starting point, and moving one circle along the extension direction of the second area 12 from the starting point cannot return to the starting point. In this embodiment, the second area 12 specifically adopts a closed ring shape, which enables the photoresist coated on the peripheral area of the battery cell to be arranged in a full circle and surround the photoresist coated on the central area of the battery cell.
[0033] Of course, when the second area 12 is specifically configured as a non-closed ring, the second area 12 is, for example, arranged on any one side or two opposite sides of the battery cell, and the remaining area is configured as the first area 11 .
[0034] In some specific embodiments, the ratio of the mesh size of the mesh 101 in the first region 11 to the mesh size of the mesh 101 in the second region 12 includes, but is not limited to, 1.3 to 1.7, specifically, 1.3, 1.4, 1.5, 1.6, or 1.7, and can be flexibly adjusted and set according to actual needs. In this way, the thickness of the photoresist coated in the central area and the thickness of the photoresist coated in the peripheral area on the surface of the solar cell can both meet the requirements.
[0035] In some embodiments, the mesh number of the mesh 101 of the first zone 11 includes but is not limited to 110 to 130, specifically for example 110, 120 or 130; the mesh number of the mesh 101 of the second zone 12 includes but is not limited to 70 to 90, specifically for example 70, 80 or 90.
[0036] In a specific embodiment, the mesh size of the mesh 101 of the first area 11 is 120, and the mesh size of the mesh 101 of the second area 12 is 80. In this way, the mesh size of the mesh 101 of the first area 11 and the mesh size of the mesh 101 of the second area 12 are set relatively reasonably. After the photoresist is coated on the solar cell using the screen structure, the peripheral areas of the solar cell have a high film thickness, and the central area has a low film thickness. The photoresist thickness of different areas of the solar cell is reasonable, which not only reduces the photoresist material in the central area and saves costs, but also the photoresist thickness of the peripheral areas is thicker, meeting the process requirements.
[0037] In one embodiment, the outer contour of the first area 11 is configured to be rectangular, circular, or elliptical; the outer contour of the second area 12 is configured to be rectangular, circular, or elliptical.
[0038] See also Figure 5 and Figure 6In one embodiment, the mesh body 10 further includes at least one third area 13 located between the first area 11 and the second area 12. The mesh size of the mesh openings 101 of the third area 13 is larger than that of the mesh openings 101 of the second area 12, and the mesh size of the mesh openings 101 of the third area 13 is smaller than that of the mesh openings 101 of the first area 11.
[0039] In some embodiments, the third area 13 can be set to one or more. When the third area 13 is set to more than one, such as Figure 6 As shown, the plurality of third regions 13 are nested and arranged in sequence from the center of the mesh body 10 to the periphery of the mesh body 10 , and the mesh count of the meshes 101 is, for example, decreasing.
[0040] In one embodiment, the meshes 101 include but are not limited to regular shapes such as circles, ellipses, polygons, and other irregular shapes. In addition, the meshes 101 in the first area 11 are arranged in an array, and the meshes 101 in the second area 12 are arranged in an array.
[0041] In one embodiment, the screen structure further includes a frame 20 disposed around the circumference of the screen body 10. The frame 20 is connected to the screen body 10.
[0042] In one embodiment, the mesh body 10 is made of a non-metallic material; and the frame 20 is made of a metallic material.
[0043] See also Figure 4 In one embodiment, a coating device includes the screen structure for manufacturing solar cells according to any of the above embodiments.
[0044] In the process of applying the photoresist to the battery cell, the above-mentioned coating device aligns the grid body 10 with the battery cell so that the first area 11 is arranged corresponding to the central area of the battery cell, and the second area 12 is arranged corresponding to the peripheral area of the battery cell, and the photoresist is respectively applied to the central area and the peripheral area of the battery cell. Among them, the mesh number of the mesh 101 of the first area 11 is greater than the mesh number of the mesh 101 of the second area 12. The thickness of the photoresist in different areas is controlled by the rule that low mesh number has a large ink transmittance and high mesh number has a small ink transmittance. In this way, the thickness of the photoresist coated on the central area of the battery cell is less than the thickness of the photoresist in the peripheral area, so that the thickness of the photoresist in the peripheral area of the battery cell is larger, which can prevent the battery cell from having "mushroom-shaped" grid line defects in the step of electroplating copper grid lines, that is, improve the problem of low efficiency caused by plating at the edge of the battery cell during electroplating; at the same time, the thickness of the photoresist in the central area of the battery cell is smaller, and the specific size is consistent with the thickness of the copper grid lines electroplated on the battery cell. In this way, there is no need to design the thickness of the photoresist in the central area of the battery cell to be the same as the thickness of the photoresist in the peripheral area, thereby reducing unnecessary materials, avoiding material waste, and greatly saving costs.
[0045] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.
[0046] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.
[0047] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.
[0048] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.
[0049] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.
[0050] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0051] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.
Claims
1. A screen structure for making solar cells, characterized in that: The screen structure for making solar cells includes: A mesh body (10), wherein the mesh body (10) is formed with a plurality of meshes (101), the mesh body (10) is provided with a first area (11) and a second area (12), the second area (12) is arranged at the periphery of the first area (11), and the mesh number of the meshes (101) of the first area (11) is greater than the mesh number of the meshes (101) of the second area (12); the first area (11) is arranged corresponding to the position of the central area of a battery cell so that photoresist can be applied to the central area of the battery cell; the second area (12) is arranged corresponding to the position of the peripheral area of the battery cell so that photoresist can be applied to the peripheral area of the battery cell.
2. The screen structure for manufacturing solar cells according to claim 1, characterized in that: The second zone (12) is arranged around the circumference of the first zone (11).
3. The screen structure for manufacturing solar cells according to claim 1, characterized in that: The ratio of the mesh number of the mesh (101) of the first zone (11) to the mesh number of the mesh (101) of the second zone (12) is 1.3 to 1.
7.
4. The screen structure for manufacturing solar cells according to claim 1, characterized in that: The mesh number of the mesh (101) of the first zone (11) is 110 to 130; the mesh number of the mesh (101) of the second zone (12) is 70 to 90.
5. The screen structure for manufacturing solar cells according to claim 1, characterized in that: The outer contour of the first area (11) is arranged to be rectangular, circular or elliptical; the outer contour of the second area (12) is arranged to be rectangular, circular or elliptical.
6. The screen structure for manufacturing solar cells according to claim 1, characterized in that: The mesh body (10) is further provided with at least one third area (13) located between the first area (11) and the second area (12), the mesh number of the mesh holes (101) of the third area (13) being greater than the mesh number of the mesh holes (101) of the second area (12), and the mesh number of the mesh holes (101) of the third area (13) being less than the mesh number of the mesh holes (101) of the first area (11).
7. The screen structure for manufacturing solar cells according to claim 1, characterized in that: The meshes (101) are circular, elliptical or polygonal; the meshes (101) in the first area (11) are arranged in an array, and the meshes (101) in the second area (12) are arranged in an array.
8. The screen structure for manufacturing solar cells according to claim 1, characterized in that: The screen structure further comprises a frame (20) arranged circumferentially around the screen body (10), and the frame (20) is connected to the screen body (10).
9. The screen structure for manufacturing solar cells according to claim 8, characterized in that: The mesh body (10) is made of non-metallic material; and the frame (20) is made of metallic material.
10. A coating device, characterized in that: The coating device comprises the screen structure for manufacturing solar cells according to any one of claims 1 to 9.