A printing screen structure for BC battery
By setting a wear-resistant material layer in the non-printing area of the screen, the problems of screen wear and ink leakage in BC battery grid line printing were solved, and the service life of the screen was significantly improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHUZHOU JIETAI NEW ENERGY TECH CO LTD
- Filing Date
- 2025-07-22
- Publication Date
- 2026-06-19
AI Technical Summary
In the existing BC battery grid line printing process, the thickness difference caused by the overlapping of the positive electrode sub-grid and the main grid frame during the third process can easily lead to screen wear and ink leakage, reducing the screen's service life.
A wear-resistant material layer is set in the non-printing area of the screen, especially at the position where the height of the grid lines on the side of the screen corresponds to the height of the grid lines on the battery cell. A PI film or nickel metal layer is fixed by hot pressing or vapor deposition to increase the thickness of the mask layer in the non-printing area to 2 times, forming an asymmetric structure to reduce wear.
It increases the lifespan of the screen by 2-3 times, reduces wear and ink leakage, and ensures the accuracy and durability of the printing effect.
Smart Images
Figure CN224375110U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of printing screens, and in particular to a printing screen structure for BC batteries. Background Technology
[0002] In the process of printing grid lines on a battery cell, screen printing is usually used to create a graphic structure on the surface of the cell. The working principle is to use a squeegee to apply an appropriate amount of paste to a pre-designed screen, allowing the paste to pass through the screen and form a grid line pattern on the surface of the cell.
[0003] Due to the technological upgrade of solar cells to BC (Browser-Cooled) cells, the grid lines or patterns are all transferred to the same surface, resulting in multiple superpositions of the original pattern structure. For example... Figure 1 and Figure 2 As shown, the grid pattern structure of a BC battery includes a positive main grid 1, a positive secondary grid 2, a negative main grid 3, a negative secondary grid 4, and a main grid frame 5. The positive main grid 1 and negative main grid 3 are alternately arranged along the transverse direction of the battery cell. The positive main grid 1 and positive secondary grid 2 are perpendicular to each other, and the positive main grid 1 intersects with and extends beyond the main grid frame 5. The negative main grid 3 and negative secondary grid 4 are perpendicular, and the negative secondary grid 4 is shorter than the positive secondary grid 2 and does not contact the main grid frame 5. Currently, the printing process for the grid structure of BC batteries in related technologies includes three printing processes. In the first printing process, a first printing screen is used to print the main grid frame 5, the positive main grid 1, and the negative main grid 3. In the second printing process, a second printing screen is used to print the positive secondary grid 2. Finally, in the third printing process, a third printing screen is used to print the negative secondary grid 4. Due to the special nature of the BC battery grid line printing process, the positive electrode sub-grid 2 and the negative electrode sub-grid 4 cannot be printed simultaneously in the same process.
[0004] The aforementioned technologies have the following shortcomings: After the paste is printed in the first two processes, a cross-linked pattern (i.e., the positive electrode sub-grid and the main grid frame intersect) will be formed on the battery cell. The thickness generated by the paste superposition at the intersection will cause the thickness of the superposition area to form a bulge at the edge of the screen during the subsequent (third) screen printing process. As the third screen is used continuously during the printing process, it is prone to wear and tear, resulting in screen failure or paste leakage, which greatly reduces the service life of the screen. Utility Model Content
[0005] In order to improve the service life of the third printing screen for BC battery grid line printing and reduce the wear of the screen caused by the superposition of grid line heights at the intersection of the positive electrode sub-grid and the main grid frame, this application provides a printing screen structure for BC batteries.
[0006] In a first aspect, this application provides a printing screen structure for BC batteries, employing the following technical solution:
[0007] A printing screen structure for BC batteries includes a screen body with a pre-designed printed area and two non-printed areas on its two sides. Both the printed and non-printed areas have a mask layer. The non-printed areas are positioned opposite to the grid lines pre-printed on the sides of the battery cell. The non-printed areas protrude towards the printed areas, and the distance S1 from the non-printed areas to the printed areas is 0.5-0.8 mm. The mask layer of the non-printed areas has a wear-resistant material layer.
[0008] By adopting the above technical solution, since the grid structure of the BC battery is asymmetrical and all grids are set on the same side of the cell, the negative electrode sub-grid needs to be printed during the third printing process. Because the positive electrode sub-grid formed in the second process is longer than the negative electrode sub-grid in the horizontal direction, and the positive electrode sub-grid overlaps with the main grid frame printed in the first process, a height difference is formed on the surface of the cell due to the superposition height. This height difference has a significant impact on the printing on both sides of the screen printing plate, which can easily cause screen wear or even ink leakage. Therefore, a wear-resistant material layer is set on the non-printing area on the side of the screen printing plate in the third process. The position of the wear-resistant material layer is opposite to the superposition height of the grid lines on the cell. This layer bears the wear caused to the screen printing plate by the superposition of the grid lines on the cell during printing, reduces the problem of wear and ink leakage on the side of the third screen printing plate, and thus improves the life of the screen printing plate.
[0009] Optionally, the wear-resistant material layer is a PI film layer or a nickel metal layer. The nickel metal layer is fixed on the screen printing body by vapor deposition, and the PI film is fixed on the screen printing body by hot pressing.
[0010] By adopting the above technical solution, the wear-resistant material layer set in the non-printing area is fixed on the screen printing body by vapor deposition or hot pressing, thus preventing the wear-resistant material layer from detaching from the screen printing body.
[0011] Optionally, the mask layer thickness in the printed area is 4-5 μm, and the mask layer thickness in the non-printed area is 8-10 μm.
[0012] By adopting the above technical solution, setting the mask layer thickness in the non-printing area to be twice that in the printing area helps to increase the screen printing plate lifespan by 2-3 times, greatly improving the lifespan. Setting the mask layer thickness in the non-printing area to 8-10μm can both resist wear and ensure the accuracy of printing work.
[0013] Optionally, the length of the non-printed area is parallel to the length direction of the battery cell, and the length S2 of the non-printed area is not less than 180mm.
[0014] Optionally, the non-printed areas on the two sides of the screen print body have an asymmetrical structure.
[0015] By adopting the above technical solution, due to the special nature of the grid structure of the BC battery, the mask layer setting in the non-printing area of the screen printing plate can cooperate with the printing of the third process of the BC battery, ensuring the printing effect while reducing wear on the screen printing plate.
[0016] Optionally, the graphic structure on the screen body is a graphic structure for printing the negative electrode sub-gate.
[0017] In summary, this application has the following beneficial effects:
[0018] 1. Because the grid structure of the BC battery is asymmetrical and all grids are located on the same side of the cell, the negative sub-grid needs to be printed during the third printing process. Since the positive sub-grid formed in the second printing process is longer than the negative sub-grid in the horizontal direction, and the positive sub-grid overlaps with the main grid frame printed in the first process, a height difference is formed on the surface of the cell due to the overlapping height. This height difference has a significant impact on the printing on both sides of the screen printing plate, which can easily cause screen wear or even ink leakage. Therefore, a wear-resistant material layer is applied to the non-printing area on the side of the screen printing plate in the third process. The location of the wear-resistant material layer is opposite to the position of the grid line overlap height on the cell. This layer bears the wear caused to the screen printing plate by the grid line overlap on the cell during printing, reducing the problem of wear and ink leakage on the side of the third screen printing plate, thereby improving the screen printing plate life.
[0019] 2. By setting the mask layer thickness in non-printing areas to be twice that in printing areas, the lifespan of the screen can be increased by 2-3 times, greatly extending its service life. Attached Figure Description
[0020] Figure 1 This is a complete grid structure diagram of the back of a BC battery.
[0021] Figure 2 For the grid structure on the back of the BC battery Figure 1 Enlarged view of a portion of the image.
[0022] Figure 3 This is a structural diagram of the screen printing structure in Example 1.
[0023] Figure 4 The web version of Example 1 is in Figure 3 Enlarged view of a portion of the image.
[0024] Figure 5 This is a structural diagram of the screen printing structure in Comparative Example 1.
[0025] Figure 6 This is the result of using the screen layout structure of Comparative Example 1.
[0026] Explanation of reference numerals in the attached diagram: 1. Positive main grid; 2. Positive secondary grid; 3. Negative main grid; 4. Negative secondary grid; 5. Main grid border; 6. Screen body; 61. Printed area; 62. Non-printed area. Detailed Implementation
[0027] The following is in conjunction with the appendix Figure 3-4 This application will be described in further detail.
[0028] Example 1
[0029] This application discloses a printing screen structure for BC batteries.
[0030] Reference Figure 3 and Figure 4 A printing screen structure for BC batteries includes a screen body 6, which is used in the third printing process of BC batteries. The screen body 6 has a printing area 61 with a pre-designed graphic structure, namely the graphic structure for the negative electrode sub-grid 4. The graphic structure on the left side of the upper half of the screen body 6 is the same as that on the right side of the lower half, that is, the length of the negative electrode sub-grid 4 is shorter than the length of the grid lines in other positions. The screen body 6 also includes a non-printing area 62, which protrudes towards the printing area 61, making the non-printing area 62 "N" shaped in the length direction. The third screen takes advantage of the fact that it does not need to print the positive electrode sub-grid 2. Originally, the length of the positive electrode sub-grid 2 of the BC battery needs to be longer than that of the negative electrode sub-grid 4. The non-printing area 62 can cover the intersection of the positive electrode sub-grid 2 and the main grid frame 5 during printing, thus reducing the wear on the screen body 6.
[0031] Both the printing area 61 and the non-printing area 62 of the screen printing body 6 have mask layers. The mask layer thickness of the printing area 61 is 5μm, and the mask layer of the non-printing area 62 has an added wear-resistant material layer on top of the 5μm thickness, making the mask layer thickness of the non-printing area 62 10μm. The wear-resistant material layer can be a PI film layer or a nickel metal layer. When the wear-resistant material layer is a PI film layer (i.e., polyimide film), the PI film is fixed to the screen printing body 6 by hot pressing. When the wear-resistant material layer is a nickel metal layer, the nickel metal layer is fixed to the screen printing body 6 by vapor deposition, ensuring its stability. The thickness of the mask layer in the non-printing area can withstand the wear of the battery cell on the screen printing plate, that is, reduce the wear on the sides of the screen printing body 6 caused by the superposition height difference formed by the curing of the battery cell after the first two printing processes, thereby increasing the service life of the screen printing body 6 and reducing the likelihood of wear on the third screen printing plate caused by the protrusion formed by the intersection of the positive electrode sub-grid 2 and the main grid frame 5 on the surface of the battery cell.
[0032] The non-printed area 62 has an asymmetrical structure that matches the grid line structure pattern of the BC battery. The length of the non-printed area 62 of the screen printing body 6 is set along the length direction of the battery cell. The protrusion distance S1 of the non-printed area 62 at the left side of the upper half and the right side of the lower half of the screen printing body 6 is 0.8mm, and the length S2 of the non-printed area 62 of the screen printing body 6 is 180mm, which is the same as the length of the battery cell. This ensures the accuracy of printing while overcoming the problem of wear caused by the superimposed grid line structure on the side of the battery cell to the screen printing body 6.
[0033] The implementation principle of a printing screen structure for BC batteries in this application embodiment is as follows: by adjusting the position of the non-printing area 62 on the side of the screen body 6 and setting the mask layer thickness of the non-printing area 62 to 10μm, it can block wear while ensuring the printing effect, and greatly improve the service life of the screen body 6.
[0034] Comparative Example 1
[0035] Reference Figure 5 A printing screen structure for BC batteries differs from Embodiment 1 in that the screen body 6 includes a printing area 61 and a non-printing area 62. Both the non-printing area 62 and the printing area 61 are provided with a mask layer of the same thickness, and the upper half and the lower half of the non-printing area 62 at the two sides of the screen body 6 are on the same straight line.
[0036] Performance testing experiment
[0037] Multiple screen printing plates from Example 1 and Comparative Example 1 were prepared and used in parallel tests during the third printing process of BC batteries to test their service life.
[0038] The test results are shown in the table below.
[0039] Example 1 Comparative Example 1 Average number of uses per screen printing plate before it shows signs of wear / times 30W 8W
[0040] The test results show that the screen structure of Embodiment 1 of this application, when used in the third printing process of BC batteries, has a lifespan 2-3 times longer than that of the ordinary screen structure in Comparative Example 1. Specifically, as... Figure 6 As shown, the screen structure of Comparative Example 1 forms obvious protrusions after multiple printings (such as the part circled in the dashed box). The location of these protrusions is prone to ink leakage after long-term printing work, resulting in a shorter service life.
[0041] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A printing screen structure for BC batteries, comprising a screen body (6), characterized in that: The screen printing body (6) has a pre-designed graphic structure printed area (61), and two sides of the screen printing body (6) have non-printed areas (62). Both the printed area (61) and the non-printed area (62) have a mask layer. The non-printed area (62) is positioned opposite to the grid line superposition area pre-printed on the side of the battery cell. The non-printed area (62) of the screen printing body (6) protrudes towards the printed area (61). The distance S1 from the non-printed area (62) to the printed area (61) is 0.5-0.8 mm. The mask layer of the non-printed area (62) has a wear-resistant material layer.
2. A printing screen structure for BC batteries according to claim 1, characterized in that: The wear-resistant material layer is a PI film layer or a nickel metal layer. The nickel metal layer is fixed on the screen printing body (6) by vapor deposition, and the PI film is fixed on the screen printing body (6) by hot pressing.
3. A printing screen structure for BC battery according to claim 1, characterized in that: The mask layer thickness of the printed area (61) is 4-5 μm, and the mask layer thickness of the non-printed area (62) is 8-10 μm.
4. The printing screen structure for BC battery according to claim 1, characterized in that: The length of the non-printed area (62) is parallel to the length direction of the battery cell, and the length S2 of the non-printed area (62) is not less than 180mm.
5. The printing screen structure for BC battery according to claim 1, characterized in that: The non-printed areas (62) on the two sides of the screen print body (6) have an asymmetrical structure.
6. A printing screen structure for BC battery according to claim 1, characterized in that: The graphic structure on the screen body (6) is a graphic structure used for printing the negative electrode sub-gate (4).