Screen printing plate with wire diameter difference
By introducing a wire diameter difference design into the mesh fabric, combining the mesh fabric with coarse and fine diameter areas, the problem of balancing screen opening rate and printing life is solved, achieving efficient silver paste flow and screen durability, and reducing production costs.
Patent Information
- Application Number
- CN202521195994.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-12
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-06-12
AI Technical Summary
Existing screen printing plates have shortcomings in balancing opening rate and printing life, resulting in high ink flow resistance, poor printability, and insufficient screen strength, which increases production costs.
The screen design employs a wire mesh with a wire diameter difference, which includes a coarse diameter region and a fine diameter region. The coarse diameter region increases the strength of the screen, while the fine diameter region increases the opening ratio. The screen structure is optimized by adjusting the wire diameter difference of the screen.
It increases the screen aperture ratio, reduces the resistance of the silver paste, extends the number of printing operations, extends the screen life, and reduces production costs.
Smart Images
Figure CN223821273U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of photovoltaic cell screen printing technology, specifically relating to a screen with a wire diameter difference. Background Technology
[0002] Screen printing is a key process in the manufacturing of solar photovoltaic cells, aiming to form a conductive thin film on the surface of the cell. The screen printing process involves a squeegee pressing printing ink onto the screen. When the ink reaches the electrode pattern area on the screen that is not blocked by the film, it penetrates the mesh and contacts the substrate (silicon wafer). As the squeegee continues to move forward, the screen tension and spacing cause the ink to detach from the screen and adhere to the substrate, thus achieving the printing purpose.
[0003] like Figure 1 As shown, the structure of a screen printing plate generally includes a screen frame 1, a mesh fabric 2 fixed in the screen frame 1, and a coating 3 attached to the mesh fabric 2. The coating can be a PI film or a latex film depending on the forming process. The mesh fabric 2 is a woven, crisscrossing mesh structure that is responsible for supporting the coating 3. The grid pattern 4 to be printed is formed on the surface of the coating 3 by laser engraving or photolithography.
[0004] In a screen printing structure, a large portion of the opening area of the ink channel is occupied by the wires that make up the screen. Therefore, during the ink discharge process from the screen, the screen inevitably creates resistance to the ink flow. With the development of photovoltaic cells, reducing the grid line width increases the light-receiving area of the cell and improves photoelectric conversion efficiency. Therefore, the mesh count of the screen needs to be increasingly higher, but the wire diameter remains constant. This further reduces the screen's aperture ratio, making it difficult for the ink to pass through the screen and resulting in poor printability. If the wire diameter of the mesh is reduced to increase the aperture ratio, the strength of the screen will inevitably decrease. During screen printing, if the screen strength is insufficient, it will break under strong squeegee pressure, significantly reducing the number of printable operations and increasing the production cost of photovoltaic cells. Utility Model Content
[0005] This invention provides a screen printing plate with a wire diameter difference to solve the problem that current screen printing plates cannot simultaneously achieve both aperture ratio and printing life.
[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows: the screen with wire diameter difference includes a screen frame, a mesh fabric fixed in the screen frame and a film attached to the surface of the mesh fabric. The film is provided with a hollow grid pattern. The mesh fabric includes a coarse diameter region and a fine diameter region. The wire diameter of the mesh in the coarse diameter region is more than 2μm larger than the wire diameter in the fine diameter region. The grid pattern is located in the fine diameter region.
[0007] Optionally, the wire diameter in the coarse diameter region is 2-8 μm larger than the wire diameter in the fine diameter region.
[0008] Excessive differences in wire diameter and mesh strength create difficulties for subsequent processing.
[0009] Optionally, the contour of the narrow diameter region is the same as the contour of the grid line pattern, and the contour of the narrow diameter region is larger than the contour of the grid line pattern.
[0010] Optionally, the outline of the narrow diameter region extends at least 30 μm beyond the outline of the grid pattern on one side, preferably 100-800 μm, and more preferably 300-500 μm.
[0011] Due to the deformation of the mesh itself, if the outer extension is too small, it will cause problems with the alignment of the subsequent lamination and laser grid pattern; if the outer extension is too large, it will provide limited support.
[0012] Optionally, the screen can be stretched at an angle, either obliquely or vertically.
[0013] Optionally, the screen printing plate is a non-woven screen printing plate, and the coating is a PI film.
[0014] Optionally, the distance between the outline of the narrow diameter region and the parallel frame edge is more than 1 cm.
[0015] Optionally, the mesh fabric is made of tungsten steel.
[0016] The technical solution provided by this utility model is as follows: By using a mesh fabric with a difference in wire diameter, the fine diameter area is conducive to improving the opening rate of the screen and reducing the resistance to the silver paste. Therefore, a higher mesh count mesh fabric can be used, which is suitable for screen printing with finer grid lines. On the other hand, the coarse diameter area is mainly used to support the mesh fabric. The high mesh count and coarse wire diameter can increase the strength of the screen, which means increasing the number of printing operations and extending the service life of the screen. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the prior art screen as described in the background section;
[0018] Figure 2 This is a partially enlarged cross-sectional view of the screen with wire diameter difference described in Example 1;
[0019] Figure 3 This is a schematic diagram of the structure in the screen printing plate with wire diameter difference described in Example 1;
[0020] Figure 4 This is a schematic diagram of the structure of the coarse diameter region and the fine diameter region described in Example 1;
[0021] Figure 5 This is a schematic diagram of the structure in the screen printing plate with wire diameter difference described in Example 2;
[0022] Figure 6 This is a schematic diagram of the structure of the coarse diameter region and the fine diameter region described in Example 2.
[0023] As shown in the figure:
[0024] Figure 1 1-Frame, 2-Mesh fabric, 3-Lamination, 4-Grid pattern;
[0025] Figures 2-6 10 - Frame, 20 - Mesh fabric, 21 - Coarse diameter area, 22 - Fine diameter area, 30 - Coating, 40 - Grid pattern. Detailed Implementation
[0026] For ease of understanding, the following description of the screen printing plate with wire diameter difference is illustrated with reference to an embodiment.
[0027] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.
[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation and positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0030] Example 1
[0031] like Figure 2 , 3As shown in Figure 4, the screen printing plate with wire diameter difference includes a frame 10, a mesh fabric 20 fixed within the frame 10, and a coating 30 attached to the surface of the mesh fabric 20. The coating 30 has a perforated grid pattern 40. The mesh fabric 20 includes a coarse-diameter region 21 and a fine-diameter region 22. The wire diameter in the coarse-diameter region is 5 μm larger than that in the fine-diameter region. The grid pattern 40 is located within the fine-diameter region 22. The mesh fabric is made of tungsten carbide, has a mesh count of 700, and an initial wire diameter of 8 μm.
[0032] See also Figure 3 The outline of the narrow diameter region 22 is the same as the outline of the grid pattern 40. The outline of the narrow diameter region 22 extends about 300 μm outward on one side compared to the outline of the grid pattern 40. The distance between the outline of the narrow diameter region 22 and the parallel grid frame 10 is more than 2 cm.
[0033] See also Figure 2 and 4 The screen printing plate is stretched at a vertical angle, meaning the final screen printing plate is a knot-free screen printing plate, and the coating 30 is a PI film.
[0034] The preparation process is as follows:
[0035] 1) Stretching and laminating: First, stretch the polyester mesh, let it stand, and then fix the polyester mesh yarn on the mesh frame to form a polyester mesh. Then, use hot melt adhesive to laminate the metal mesh cloth to the middle area of the polyester mesh to form a composite mesh yarn. Under the action of the top mesh machine, a certain mesh tension is obtained, and the composite mesh yarn is fixed to another mesh frame to obtain a composite mesh plate.
[0036] 2) Composite polymer mask: A polymer mask is composited on the upper and lower surfaces of the composite screen fabric. In this embodiment, it is made of PI material. The polymer film covers the coarse diameter area 21. The composite method can be to remove the area that does not need to be covered from the PI film according to the design, and then composite it onto the surface of the screen fabric by hot pressing, or to form a polymer mask in the designed covered area by coating, exposure and development of photosensitive PI adhesive.
[0037] 3) Fine-diameter region 22 wire diameter processing: The screen with the composite polymer mask is immersed in the etching solution. The etching solution can be an acidic solution, an alkaline solution, or other solutions that can corrode stainless steel or tungsten steel. In this embodiment, the etching solution is a hydrochloric acid solution with a concentration of 8wt% HCl (approximately 2.28 mol / L). The temperature is controlled at 30°C and the screen is left to stand for 50 minutes. After removal, the etching solution is washed off with water and dried. The drying conditions are drying at 50°C for 15 minutes. After etching, the wire diameter is measured using a high-precision three-dimensional measuring machine.
[0038] 4) Thread cutting: The warp threads in the fine diameter region 22 are cut and removed by laser.
[0039] 5) Pressing: The PI film layer is pressed onto the P surface of the mesh by high temperature pressing to form a coating 30 on the composite mesh;
[0040] 6) Laser: After setting the laser parameters, line width parameters, and size parameters, perform laser operation to form the required grid pattern 40 on the film layer.
[0041] Example 2
[0042] like Figure 5 and 6 The difference from Example 1 is that the screen is stretched at an oblique angle, which is a traditional screen, so there is no wire-drawing step in the preparation process. Also, the contours of the fine diameter region 22 and the grid pattern 40 are different. The grid pattern 40 is located within the fine diameter region 22. In this example, the fine diameter region 22 is rectangular, and each side of the fine diameter region 22 is 1 μm away from the parallel sides of the screen frame 10. The mesh count of the screen is 500 meshes, and the initial wire diameter is 11 μm.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of this utility model.
Claims
1. A screen printing plate with a wire diameter difference, characterized in that, The device includes a frame, a mesh fabric fixed within the frame, and a coating attached to the surface of the mesh fabric. The coating has a perforated grid pattern. The mesh fabric includes a coarse-diameter region and a fine-diameter region. The wire diameter in the coarse-diameter region is more than 2µm larger than the wire diameter in the fine-diameter region. The grid pattern is located in the fine-diameter region.
2. The screen printing plate with wire diameter difference according to claim 1, characterized in that, The wire diameter in the coarse diameter region is 2-8µm larger than that in the fine diameter region.
3. The screen printing plate with wire diameter difference according to claim 1, characterized in that, The contour of the narrow diameter region is the same as the contour of the grid line pattern, and the contour of the narrow diameter region is larger than the contour of the grid line pattern.
4. The screen printing plate with wire diameter difference according to claim 3, characterized in that, The outline of the narrow diameter region extends at least 30µm beyond the outline of the corresponding grid pattern on one side.
5. The screen printing plate with wire diameter difference according to claim 4, characterized in that, The outline of the narrow diameter region extends 100-800µm beyond the outline of the corresponding grid pattern on one side.
6. The screen printing plate with wire diameter difference according to claim 5, characterized in that, The outline of the narrow diameter region extends 300-500µm beyond the outline of the corresponding grid pattern on one side.
7. The screen printing plate with wire diameter difference according to claim 1, characterized in that, The screen is stretched at an angle, either obliquely or vertically.
8. The screen printing plate with wire diameter difference according to claim 5, characterized in that, The screen printing plate is a non-woven screen printing plate, and the coating is a PI film.
9. The screen printing plate with wire diameter difference according to claim 1, characterized in that, The distance between the outline of the narrow diameter region and the parallel frame edge is more than 1 cm.
10. The screen printing plate with wire diameter difference according to claim 1, characterized in that, The mesh fabric is made of tungsten steel.