Silicon wafer printing screen
The silicon wafer printing mesh with strategically placed recesses addresses the issue of material leakage by ensuring precise alignment and contact during the printing of second grid lines, thereby improving product quality and performance.
Patent Information
- Application Number
- CN202421893309.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2024-07-16
- Filing Date
- 2024-08-06
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-08-06
AI Technical Summary
In the prior art, when printing the second gate line, the screen of the silicon wafer printing plate cannot fit closely with the bottom surface of the silicon wafer because the mesh is supported by the first gate line, resulting in slurry leakage and affecting product performance.
A groove corresponding to the first gate line printing position is provided on the mesh cloth, and a second gate line pattern opening is provided on the groove side. The outer contour of the groove is greater than the edge of the first gate line, and the depth is not less than its thickness. The shape is adapted to the first gate line to form a reverse buffering effect to prevent the mesh cloth from being supported.
By setting the grooves, ensure that the second gate pattern opening is closely fitted with the bottom surface of the silicon wafer, avoid slurry leakage, and improve product performance and printing accuracy.
Smart Images
Figure CN223100217U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of screen printing, and particularly relates to a silicon wafer printing screen. Background Art
[0002] As a printing method with mature technology, high precision and low cost, the application of screen printing technology in the photovoltaic industry makes the manufacturing process of photovoltaic cells more precise and efficient. In the metallization process of photovoltaic cell wafers, screen printing technology is widely used to form the front and back electrodes of solar cells. Using screen printing technology, conductive pastes containing metals (such as silver paste and aluminum paste) can be imprinted on the silicon wafer through the screen mesh holes, forming a good ohmic contact with the silicon wafer and reducing the loss during the process of collecting and leading out current.
[0003] In the prior art, as shown in Figure 1 , during the process of printing grid lines on the silicon wafer 6, a step-by-step printing method is usually adopted, that is, first print the first grid line 1 and form a raised structure through sintering and curing. When it comes to the second step, as shown in Figure 2 , that is, when printing the second grid line 2, problems will emerge. Since the first grid lines 1 existing on both sides serve as supports, the screen cloth 5 is lifted, resulting in that when printing the second grid line 2, the screen cloth cannot be completely flatly attached to the bottom surface of the silicon wafer 6. This uneven contact will cause gaps during the printing process, and the paste often leaks along these gaps. This leakage phenomenon will ultimately form obvious serrations at the edge of the second grid line 2, which not only affects the appearance quality of the second grid line 2, but more importantly, will have an adverse impact on the overall performance of the product. Summary of the Utility Model
[0004] The purpose of the utility model is to provide a silicon wafer printing screen to solve the technical problem in the prior art that during the printing process of the second grid line, the paste leaks along the gaps due to the inability of the printing screen to be completely and tightly flatly attached to the bottom surface of the silicon wafer, affecting the product performance.
[0005] To achieve the above purpose, the utility model adopts the following technical solutions:[[]]
[0006] A silicon wafer printing screen includes a screen cloth and a screen frame. The screen cloth is arranged inside the screen frame, and a groove is formed on the screen cloth. The groove corresponds to the printing position of the first grid line, and a second grid line graphic opening is arranged at the position of the screen cloth corresponding to the second grid line.
[0007] Preferably, the groove is formed at the glue layer on the lower surface of the screen cloth.
[0008] Preferably, the second grid line graphic opening is formed at the glue layer on the surface of the screen cloth for the printing material to pass through.
[0009] Preferably, the outer contour of the groove is not smaller than the edge of the first grid line.
[0010] Preferably, the depth of the groove is not smaller than the thickness of the first grid line.
[0011] Preferably, during printing, the inner surface of the groove fits with the outer surface of the first grid line.
[0012] Preferably, during printing, a gap is provided between the inner surface of the groove and the outer surface of the first grid line.
[0013] Preferably, the shape of the groove is adapted to the shape of the first grid line.
[0014] Preferably, it further includes a strengthening structure which is arranged on the mesh cloth to increase the structural strength.
[0015] Preferably, the mesh cloth is composed of a plurality of micron-level silk threads. The plurality of silk threads do not cross each other and have the same height. A glue layer is coated on the plurality of micron-level silk threads.
[0016] Compared with the prior art, the present utility model has the following beneficial effects:
[0017] The present utility model discloses a silicon wafer printing stencil. A groove is opened on the mesh cloth. The groove corresponds to the printing position of the first grid line. For the thickness of the first grid line formed after printing and curing first, a reverse buffer is formed. By providing the groove, the opening of the second grid line pattern on the normal height plane can better closely fit the bottom surface of the silicon wafer to be printed. Through the setting of the groove, the mesh cloth is prevented from being supported by the first grid line. By setting the corresponding height difference, the generation of a gap between the opening of the second grid line pattern and the bottom surface of the silicon wafer to be printed is avoided, and the leakage of the paste is avoided, thereby improving the performance of the product.
[0018] Further, the outer contour of the groove is larger than the edge of the first grid line to ensure complete accommodation of the first grid line and make up for the thickness difference.
[0019] Further, the depth of the groove is not smaller than the thickness of the first grid line to ensure making up for the thickness difference formed by the first grid line and ensure the effectiveness of printing.
[0020] Further, the shape of the groove is adapted to the shape of the first grid line to ensure complete and fitting accommodation of the first grid line and make up for the thickness difference.
[0021] Further, a strengthening structure is provided to strengthen the structural strength of the device structure. Description of the Drawings
[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.
[0023] Figure 1 It is a finished drawing of silicon wafer printing;
[0024] Figure 2 It is a cross-sectional view when printing the second grid line in the prior art;
[0025] Figure 3 It is a schematic structural diagram of the present invention;
[0026] Figure 4 It is a partial cross-sectional view of the present invention in the A-A direction;
[0027] Figure 5 It is a cross-sectional view when printing the second grid line of the present invention;
[0028] Figure 6 It is an enlarged schematic view of the mesh structure of the present invention.
[0029] Wherein: 1 - first grid line; 2 - second grid line; 3 - groove; 4 - opening of the second grid line pattern; 5 - mesh; 501 - wire yarn; 6 - mesh frame; 7 - silicon wafer; 8 - strengthening structure. Specific embodiments
[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.
[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the present invention to be protected, but only represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.
[0032] It should be noted that: similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0033] In the description of the embodiments of the present utility model, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, it is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present utility model. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.
[0034] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.
[0035] In the description of the embodiments of the present utility model, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.
[0036] The following further describes the present utility model in detail with reference to the drawings:
[0037] See Figure 1 , taking the printing pattern on the silicon wafer as an example, during the grid line printing process, the first grid line 1 and the second grid line 2 are printed in 2 times. First, the first grid line 1 is printed, and then sintered and solidified to finally form a convex structure. When printing the second grid line 2, see Figure 2 , the screen cloth is supported and lifted by the first grid lines 1 on both sides. The printing film of the second grid line 2 cannot be completely closely attached to the bottom surface of the silicon wafer, and gaps are easily generated. Second, during the printing process of the grid line 2, the paste leaks along the gaps, and finally there are obvious sawteeth at the edge of the printed second grid line 2. Here, the grid line printed first is called the first grid line 1, and the grid line printed later is called the second grid line 2;
[0038] This application proposes a silicon wafer printing screen plate, see Figure 3, including a mesh cloth 5 and a mesh frame 6. The mesh cloth 5 is arranged inside the mesh frame 6, and a groove 3 is formed on the mesh cloth 5. The groove 3 corresponds to the printing position of the first grid line 1. A plurality of second grid line graphic openings 4 are arranged at one side of the groove 3 corresponding to the second grid line 2. By forming a groove 3 on the mesh cloth, and the groove 3 corresponding to the printing position of the first grid line, a reverse buffer is formed for the thickness of the first grid line 1 formed after printing and curing. By setting the groove 3, see Figure 5 , so that the second grid line graphic openings 4 on the normal height plane can better closely adhere to the bottom surface of the silicon wafer to be printed. Through the setting of the groove 3, the mesh cloth 5 is prevented from being supported by the first grid line 1. By setting a corresponding height difference, the generation of a gap between the second grid line graphic openings 4 and the bottom surface of the silicon wafer to be printed is avoided, and the leakage of the paste is avoided, thereby improving the performance of the product.
[0039] In some embodiments, the outer contour of the groove 3 is larger than the edge of the first grid line 1 to ensure complete accommodation of the first grid line and make up for the thickness difference.
[0040] In some embodiments, the depth of the groove 3 is not less than the thickness of the first grid line 1 to ensure making up for the thickness difference formed by the first grid line 1 and ensure the effectiveness of printing.
[0041] Further preferably, when the depth of the groove 3 is equal to the thickness of the first grid line 1, during printing, the inner surface of the groove 3 fits with the outer surface of the first grid line 1.
[0042] Further preferably, when the depth of the groove 3 is greater than the thickness of the first grid line 1, during printing, a gap is provided between the inner surface of the groove 3 and the outer surface of the first grid line 1.
[0043] In some embodiments, the shape of the groove 3 is adapted to the shape of the first grid line 1 to ensure complete and fitting accommodation of the first grid line 1 and make up for the thickness difference.
[0044] In some embodiments, see Figure 6 , the mesh cloth 5 is composed of a plurality of micron-level silk threads 501. The plurality of silk threads 501 do not cross each other and have the same height. A glue layer is coated on the plurality of micron-level silk threads 501.
[0045] In some embodiments, the groove 3 is formed at the glue layer on the surface of the mesh cloth 5 and is located at the bottom of the glue layer. The second grid line graphic openings 4 are formed at the glue layer on the surface of the mesh cloth 5 for the printing material to pass through.
[0046] In some embodiments, see Figure 4, to increase the structural strength of the printing screen plate, it further includes a strengthening structure 8. The strengthening structure 8 is disposed on the mesh cloth 5. The strengthening structure 8 is made of, but not limited to, polymer materials. The strengthening structure 8 is disposed on one side of the doctor blade surface or the printing surface of the mesh cloth 5. In addition, the strengthening structure 8 is disposed in the pattern area (the area formed by the graphic opening 4) or the non-pattern area of the mesh cloth 5, not limited to the positions shown in the drawings of this application. Moreover, the shape, quantity, and setting position of the strengthening structure 8 can be adjusted according to actual requirements without affecting the normal use function of the device structure.
[0047] Further preferably, the strengthening structure 8 is arranged perpendicular or obliquely staggered with the silk thread 501.
[0048] In some embodiments, laser etching or chemical corrosion is performed on the adhesive layer on the surface of the mesh cloth for printing the second grid line 2, and finally a groove 3 with a specific shape and depth is formed. The outer contour of the groove 3 is slightly larger than the edge of the first grid line 1, and the depth is slightly smaller than or exceeds the thickness of the first grid line 1. When printing the second grid line 2, the groove 3 on the surface of the mesh cloth can just partially or completely coincide with the first grid line 1, making the mesh cloth easier to closely fit with the surface of the silicon wafer, thereby avoiding the leakage of the paste.
[0049] In summary, the silicon wafer printing screen plate of this application is innovatively designed. Grooves 3 are specially provided on the mesh cloth 5, and the positions of these grooves 3 are precisely corresponding to the printing positions of the first grid lines 1. The function of these grooves 3 is that when the first grid lines 1 are printed and cured, the thickness formed can form a reverse buffering effect at the grooves 3 to avoid the formation of a thickness difference. In this way, when printing the second grid lines 2, due to the existence of the grooves 3, the mesh cloth 5 will not be supported by the previously printed first grid lines 1, enabling the graphic openings 4 of the second grid lines to better closely fit with the bottom surface of the silicon wafer to be printed on a normal plane.
[0050] The ingenious part of this groove 3 design is that it effectively solves the problem of non-fitting caused by the mesh cloth 5 being supported by the first grid lines 1, thereby avoiding the possible gaps generated during the printing process of the second grid lines 2 due to non-fitting of the mesh cloth. These gaps are the main cause of paste leakage, and the leakage of the paste will in turn cause the edges of the second grid lines 2 to be serrated, affecting the performance of the product.
[0051] Therefore, by setting such grooves 3 with a reverse buffering effect and precisely controlling their height difference, we have successfully avoided the generation of gaps between the graphic openings 4 of the second grid lines and the bottom surface of the silicon wafer to be printed, thereby preventing the leakage of the paste and significantly improving the performance of the product. This innovative design not only improves the printing accuracy and quality but also enhances the reliability and stability of the product.
[0052] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, various modifications and variations can be made to the present utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A silicon wafer printing stencil, characterized in that It includes a mesh cloth (5) and a mesh frame (6). The mesh cloth (5) is arranged inside the mesh frame (6), and a groove (3) is formed in the mesh cloth (5). The groove (3) corresponds to the printing position of the first grid line (1), and a second grid line graphic opening (4) is provided at the position of the mesh cloth (5) corresponding to the second grid line (2).
2. A silicon wafer printing screen plate according to claim 1, characterized in that, The groove (3) is formed at the adhesive layer on the lower surface of the mesh cloth (5).
3. A silicon wafer printing screen plate according to claim 1, characterized in that, The second grid line graphic opening (4) is formed at the adhesive layer on the surface of the mesh cloth (5) to allow printing materials to pass through.
4. A silicon wafer printing screen plate according to claim 1, characterized in that, The outer contour of the groove (3) is not smaller than the edge of the first grid line (1).
5. A silicon wafer printing screen plate according to claim 1, characterized in that, The depth of the groove (3) is not smaller than the thickness of the first grid line (1).
6. A silicon wafer printing screen plate according to claim 5, characterized in that, During printing, the inner surface of the groove (3) is attached to the outer surface of the first grid line (1).
7. A silicon wafer printing screen plate according to claim 5, characterized in that, During printing, a gap is provided between the inner surface of the groove (3) and the outer surface of the first grid line (1).
8. A silicon wafer printing screen plate according to claim 1, characterized in that, The shape of the groove (3) is adapted to the shape of the first grid line (1).
9. A silicon wafer printing screen plate according to claim 1, characterized in that, It further includes a strengthening structure. The strengthening structure (8) is arranged on the mesh cloth (5) to increase the structural strength.
10. A silicon wafer printing screen plate according to claim 1, characterized in that, The mesh cloth (5) is composed of a number of micron-level silk threads (501). The number of the silk threads (501) do not cross each other and have the same height. A glue layer is coated on the number of micron-level silk threads (501).