Surface coating structure and process for prolonging service life of screen printing plate

Abstract

The invention relates to the technical field of screen printing plates, in particular to a surface coating structure and process for prolonging the service life of a screen printing plate, and the surface coating structure comprises a screen frame, a metal net is arranged in the screen frame, a pattern area right opposite to a battery piece is arranged on the metal net, and a plurality of pattern openings used for printing electrode grid lines on the battery piece are formed in the pattern area. The pattern area comprises a long edge and a wide edge, the direction of the long edge of the pattern area is parallel to the moving direction of the scraper, the metal net comprises a P surface facing the battery piece and an S surface opposite to the battery piece, the P surface is covered with a printing PI film, the S surface is covered with a reinforcing PI film, and the reinforcing PI film is provided with a notch structure used for exposing a pattern opening. And a layer of reinforced PI film is additionally arranged on the S surface to wrap and protect the metal net, and when the metal net is extruded by the scraper, the reinforced PI film can share most pressure, so that the metal net is protected, and the overall service life is prolonged. And the gap structure ensures that the silver paste can normally penetrate through the pattern area for silk-screen printing.

Description

Technical Field

[0001] The present application relates to the technical field of screen printing, and in particular to a surface coating structure and process for increasing the service life of screen printing. Background Art

[0002] During the screen printing process of solar cells, a screen is used to print the electrode grid lines on the surface of the cell. Screen printing refers to using a silk screen as a base and using a photosensitive plate making method to create a screen printing plate with images and text.

[0003] In the prior art, a screen for printing solar cells typically includes a screen frame, a stainless steel mesh fixed to the bottom of the screen frame, and a polymer composite layer composited to the stainless steel mesh. The polymer composite layer is laser processed to obtain a pattern area, thereby achieving the effect of printing a pattern.

[0004] Silver paste and scraper cooperate with each other to perform screen printing through the pattern area, but the strength of the pattern area is weakened due to the presence of openings. After long-term use, the pattern area is prone to breakage, making the screen scrapped and having a short service life. Summary of the Invention

[0005] In order to increase the service life of the screen, the present application provides a surface coating structure and process for enhancing the service life of the screen.

[0006] One of the purposes of this application is to provide a surface coating structure that increases the service life of the screen, using the following technical solutions: A surface coating structure for enhancing the service life of the screen includes a screen frame, a metal mesh is provided in the screen frame, a pattern area is provided on the metal mesh and is opposite to the battery cell, a plurality of pattern openings for printing electrode grid lines on the battery cell are provided in the pattern area, the pattern area includes a long side and a wide side, the long side direction of the pattern area is parallel to the movement direction of the scraper, the metal mesh includes a P surface facing the battery cell and an S surface facing away from the battery cell, the P surface is covered with a printed PI film, the S surface is covered with a reinforced PI film, and the reinforced PI film is provided with a notch structure for exposing the pattern opening.

[0007] By adopting the above technical solution, an additional layer of reinforced PI film is added to the S surface to protect the metal mesh. When the metal mesh is squeezed by the scraper, the reinforced PI film can share most of the pressure, thereby protecting the metal mesh and extending its overall service life. The notched structure ensures that the silver paste can pass through the pattern area for screen printing.

[0008] Preferably, the notch structure is a square hole located in the center of the reinforced PI film and facing the pattern area, and the pattern area is located in the square hole.

[0009] By adopting the above technical solution, the area of ​​the square hole is larger than the area of ​​the pattern area. During printing, the silver paste is poured into the square hole and printed on the cell through the pattern area. The reinforced PI film protects the surrounding of the metal mesh.

[0010] Preferably, the notch structure is a square hole located in the center of the reinforced PI film opposite to the pattern area, the square hole includes two short sides parallel to the wide sides, the two short sides are located between the two wide sides, and a reinforcement area is provided on the side opposite to the short side, and a number of printing grooves for printing electrode grid lines are opened in the reinforcement area.

[0011] By adopting the above technical solution, when printing the battery cell, the metal mesh is located directly above the battery cell, the pattern area should be directly opposite the battery cell, and usually the area of ​​the pattern area is not less than the area of ​​the battery cell. Battery cell printing is usually an assembly line operation, with the battery cells arranged in a linear direction and moved sequentially to the bottom of the metal mesh for screen printing. However, when the battery cells of different manufacturers are arranged, the spacing between the battery cells is also different, but the position of the scraper and the metal mesh is fixed, and the position of the battery cell when it moves to the bottom of the metal mesh is usually different compared to the starting and landing points of the metal mesh and the scraper. When the scraper falls, it moves downward toward the metal mesh, moves to the edge of the metal mesh, presses down against the metal mesh and contacts the upper surface of the battery cell, then slides along the surface of the battery cell to the other side, and lifts the knife to complete the printing.

[0012] Because the spacing between cells varies from manufacturer to manufacturer, and the cells are positioned differently below the metal screen, the scraper's contact area with the top surface of the cell also varies. For example, if the cell is positioned on the metal screen toward the scraper's drop point, the scraper will contact the cell prematurely, impacting the cell and squeezing and abrading the edges of the patterned area on the screen.

[0013] Therefore, the length of the square hole is smaller than the two sides of the pattern area, and additional reinforcement areas are provided on both sides of the square hole. The two sides of the pattern area are located on both sides of the pattern area, thereby providing additional reinforcement on both sides of the pattern area, increasing the additional strength on both sides of the pattern area, and thereby increasing the overall service life.

[0014] Preferably, the notch structure includes a plurality of grid line grooves opened on the reinforced PI film, and the grid line grooves are directly opposite to the electrode grid lines on the surface of the solar cell.

[0015] By adopting the above technical solution, only grid line grooves for printing electrode grid lines are opened on the strengthened PI film, and the rest of the parts are retained, thereby improving the wrapping and protection effect of the metal mesh, thereby improving the overall structural strength and extending the service life.

[0016] Preferably, the side of the printed PI film facing the battery cell is covered with a protective PI film, and the protective PI film is provided with a protective notch for exposing the pattern opening.

[0017] By adopting the above technical solution, the protective PI film protects the P surface and cooperates with the reinforced PI film to wrap the upper and lower surfaces of the metal mesh, further enhancing the protection effect and extending the service life.

[0018] Preferably, the protective gap is a protective hole located in the center of the protective PI film and facing the pattern area, and the pattern area is located in the protective hole.

[0019] By adopting the above technical solution, the protective holes are used for silver paste seepage, and the protective PI film protects the surrounding areas of the metal mesh.

[0020] Preferably, the protective gap is a protective hole located in the center of the protective PI film opposite to the pattern area, and the square hole includes two protective edges parallel to the wide edges, and the two protective edges are located between the two wide edges. A protective area is provided on the side opposite to the protective edge, and a number of silk screen grooves for printing electrode grid lines are opened in the protective area.

[0021] By adopting the above technical solution, the protective area protects both sides of the pattern area, thereby improving the structural strength and extending the service life.

[0022] Preferably, the protective gap includes a plurality of grid line through grooves opened on the protective PI film, and the grid line through grooves are directly opposite to the electrode grid lines on the surface of the battery cell.

[0023] Another object of the present application is to provide a surface coating process for increasing the service life of the screen, using the following technical solution:

[0024] The surface coating process for increasing the service life of the screen is used to manufacture the surface coating structure for increasing the service life of the screen, and includes the following steps: S1. Cover the metal mesh S surface with a reinforced PI film; S2, cutting a notch structure on the reinforced PI film; S3, removing the excess reinforced PI film cut; S4, compounding the reinforced PI film onto the S surface of the metal mesh; S5. Turn the metal mesh over so that the P side faces upwards and attach a protective PI film to the P side. S6. Cut a protective notch on the protective PI film; S7, removing the excess protective PI film cut; S8. Composite the protective PI film, the metal mesh and the reinforced PI film.

[0025] In summary, this application has the following beneficial technical effects: By strengthening the setting of the PI film and strengthening the PI film's wrapping and protection of the metal mesh, the structural strength of the metal mesh is improved, thereby extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of a screen frame and a metal screen in an embodiment; Figure 2 2. It is a schematic structural diagram of the side surface of the metal mesh in the embodiment; Figure 3 Schematic diagram of the structure of the reinforced PI film in Example 1; Figure 4 is a schematic structural diagram of the reinforced PI film in Example 2; Figure 5 This is a schematic structural diagram of the scraper printing in the second embodiment; Figure 6 is a schematic structural diagram of the reinforced PI film in Example 3; Figure 7 Schematic diagram of the structure of the protective PI film in Example 4; Figure 8 Schematic diagram of the structure of the protective PI film in Example 5; Figure 9 Schematic diagram of the structure of the protective PI film in Example 6;.

[0027] Description of reference numerals: 1. Screen frame; 2. Metal mesh; 21. Pattern area; 22. Pattern opening; 23. Long side; 24. Wide side; 25. S side; 26. P side; 3. Solar cell; 4. Reinforced PI film; 41. Square hole; 42. Square hole; 421. Short side; 43. Reinforced area; 44. Printing groove; 45. Gate line groove; 5. Protective PI film; 51. Protective hole; 52. Protective hole; 521. Protective edge; 53. Protective area; 54. Silk screen groove; 55. Gate line groove; 6. Printed PI film. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with all the accompanying drawings.

[0029] Example

[0030] The embodiment of the present application discloses a surface coating structure that enhances the service life of the screen. Figures 1 to 2, including a screen frame 1, inside which there is a metal mesh 2. The metal mesh 2 includes a P side 26 facing the battery cell 3 and an S side 25 facing away from the battery cell 3. The P side 26 is covered with a printed PI film 6. There is a pattern area 21 on the metal mesh 2 and the printed PI film 6 that is directly opposite to the battery cell 3. Inside the pattern area 21, there are a number of pattern openings 22 for printing electrode grid lines on the battery cell 3. Silver paste is placed on the S side 25, and a squeegee moves from one side of the metal mesh 2 to the other side, pressing the silver paste out of the pattern openings 22 and pressing it onto the battery cell 3 to form electrode grid lines.

[0031] The pattern area 21 includes a long side 23 and a wide side 24, and the direction of the long side 23 is parallel to the movement direction of the squeegee. That is, the squeegee moves from one wide side 24 of the pattern area 21 to the other wide side 24.

[0032] There is a reinforcing PI film 4 on the S side 25, and there is a notch structure on the reinforcing PI film 4 for exposing the pattern openings 22. The surface of the printed PI film 6 facing the battery cell 3 is covered with a protective PI film 5, and there is a protective notch on the protective PI film 5 for exposing the pattern openings 22. The reinforcing PI film 4 and the protective PI film 5 clamp and wrap the upper and lower sides of the metal mesh 2, thereby protecting the metal mesh 2. When the metal mesh 2 deforms during printing, the reinforcing PI film 4 and the protective PI film 5 deform simultaneously, sharing the pressure of the metal mesh 2, thus extending the overall service life.

[0033] Example 1

[0034] Refer to Figures 1 to 3 , the notch structure is a square hole 41 located at the center of the reinforcing PI film 4 and directly opposite to the pattern area 21, and the pattern area 21 is located inside the square hole 41. The size of the pattern area 21 is smaller than the size of the square hole 41. The reinforcing PI film 4 is overall in the shape of a "hui" character, with the center of the reinforcing PI film 4 hollowed out, completely exposing the pattern area 21 for the leakage of silver paste, and the reinforcing PI film 4 protects the four sides of the metal mesh 2.

[0035] Example 2

[0036] The difference between Example 2 and Example 1 lies in the different notch structures: Refer to Figure 1 , Figure 2 and Figure 4 , the notch structure is a square hole 42 located at the center of the reinforcing PI film 4 and directly opposite to the pattern area 21. The square hole 42 includes two short sides 421 parallel to the wide side 24. The length of the square hole 42 is smaller than the length of the pattern area 21, and the width of the square hole 42 is the same as the width of the pattern area 21.

[0037] Refer to Figure 1 , Figure 2 and Figure 4The two short sides 421 are located between the two wide sides 24, and a reinforcement area 43 is provided between the short side 421 and the adjacent wide side 24. The reinforcement area 43 is located on both sides of the length direction of the pattern area 21, and a plurality of printing grooves 44 for printing electrode grid lines are opened in the reinforcement area 43.

[0038] Reference Figure 1 、 Figure 2 and Figure 4 The area of ​​the square hole 42 is smaller than the area of ​​the pattern area 21, and the width of the square hole 42 is smaller than the width of the pattern area 21, that is, both sides of the pattern area 21 are blocked by the reinforced PI film 4, but a reinforced area 43 is added to the blocked area. The printing groove 44 in the reinforced area 43 can ensure that the motor grid lines on both sides of the pattern area 21 can be printed normally, while the remaining parts are blocked by the reinforced PI film 4, thereby improving the overall structural strength.

[0039] Reference Figure 1 、 Figure 2 、 Figure 4 and Figure 5 When printing the battery cell 3, the metal mesh 2 is located directly above the battery cell 3. The pattern area 21 should be directly opposite the battery cell 3, and the area of ​​the pattern area 21 should generally be no smaller than the area of ​​the battery cell 3. The printing of battery cells 3 is typically done in an assembly line, with the battery cells 3 arranged in a linear direction and sequentially moved under the metal mesh 2 for screen printing. As the scraper descends, it tilts downward toward the metal mesh 2, moves to the edge of the metal mesh 2, presses down against the metal mesh 2, and contacts the top surface of the battery cell 3. It then slides along the surface of the battery cell 3 to the other side, and the scraper is lifted to complete printing.

[0040] However, when battery cells 3 are arranged by different manufacturers, the spacing between battery cells 3 is also different, but the positions of the scraper and the metal mesh 2 are fixed. Therefore, the position of the battery cell 3 when it moves under the metal mesh 2 is usually different from the starting and landing points of the metal mesh 2 and the scraper.

[0041] Because the spacing between battery cells 3 varies between manufacturers, and the positions of the battery cells 3 below the metal mesh 2 vary, the scraper's contact area with the top surface of the battery cells 3 varies when it descends and lifts. For example, if the battery cells 3 are located on the metal mesh 2 closer to the scraper's drop point, the scraper will contact the battery cells 3 prematurely when it descends, impacting the battery cells 3. This will also squeeze and wear both sides of the patterned area 21 of the screen, causing severe wear on both sides of the patterned area 21 and shortening the scraper's service life.

[0042] The provision of the reinforcement area 43 can protect both sides of the pattern area 21 , thereby improving the structural strength and extending the service life.

[0043] Example 3

[0044] The difference between the third embodiment and the first embodiment is that the gap structure is different: Figure 1 、 Figure 2 and Figure 6 The notch structure includes several gridline slots 45 formed in the reinforced PI film 4. These slots 45 align with the electrode gridlines on the surface of the cell 3. The reinforced PI film 4 only has gridline slots 45 for printing the electrode gridlines, leaving the rest of the film untouched. This improves the wrapping and protection of the metal mesh 2, thereby enhancing the overall structural strength and extending its service life.

[0045] Example 4

[0046] Reference Figure 1 、 Figure 2 and Figure 7 The protective gap is a protective hole 51 located at the center of the protective PI film 5 and facing the pattern area 21 , and the pattern area 21 is located in the protective hole 51 .

[0047] Example 5

[0048] The difference between the fifth embodiment and the fourth embodiment is that the structure of the protection gap is different: Figure 1 、 Figure 2 and Figure 8 The protective gap is a protective hole 52 located in the center of the protective PI film 5 and opposite to the pattern area 21. The square hole 42 includes two protective edges 521 parallel to the wide sides 24. The two protective edges 521 are located between the two wide sides 24. A protective area 53 is provided on the side opposite to the protective edge 521, and a number of silk screen grooves 54 for printing electrode grid lines are opened in the protective area 53.

[0049] Example 6

[0050] The difference between the sixth embodiment and the fourth embodiment is that the structure of the protection gap is different: Figure 1 、 Figure 2 and Figure 9 The protective gap includes a plurality of grid line grooves 55 opened on the protective PI film 5, and the grid line grooves 55 are directly opposite to the electrode grid lines on the surface of the battery cell 3.

[0051] Furthermore, the three types of protective notches in Examples 4 to 6 can be arbitrarily combined with the three notch structures in Examples 1 to 3. For example, the notch structure in Example 1 can be combined with the protective notch in Example 4 to form a coating structure, or it can be combined with the protective notch in Example 5 or 6 to form a coating structure, and the same applies to Examples 2 and 3.

[0052] Example 7

[0053] The present application discloses a surface coating process for extending the service life of a screen, and is used to manufacture the surface coating structure for extending the service life of a screen in the above embodiment, including the following steps: S1. Cover the metal mesh S surface with a reinforced PI film; S2, cutting a notch structure on the reinforced PI film by laser; S3, removing the excess reinforced PI film cut; S4, compounding the reinforced PI film onto the S surface of the metal mesh; S5. Turn the metal mesh over so that the P side faces upwards and attach a protective PI film to the P side. S6. Cut a protective gap on the protective PI film by laser; S7, removing the excess protective PI film cut; S8. Composite the protective PI film, the metal mesh and the reinforced PI film.

[0054] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A surface coating structure for enhancing the service life of a screen, comprising a screen frame (1), a metal screen (2) provided in the screen frame (1), a pattern area (21) directly facing a battery cell (3) provided on the metal screen (2), a plurality of pattern openings (22) for printing electrode grid lines on the battery cell (3) provided in the pattern area (21), the pattern area (21) comprising a long side (23) and a wide side (24), the long side (23) of the pattern area (21) being parallel to the movement direction of a scraper, the metal screen (2) comprising a P surface (26) facing the battery cell (3) and an S surface (25) facing away from the battery cell (3), characterized in that: The P surface (26) is covered with a printed PI film (6), the S surface (25) is covered with a reinforced PI film (4), and the reinforced PI film (4) is provided with a notch structure for exposing a pattern opening (22).

2. The surface coating structure for extending the service life of a screen according to claim 1, characterized in that: The notch structure is a square hole (41) located at the center of the reinforced PI film (4) and facing the pattern area (21), and the pattern area (21) is located in the square hole (41).

3. The surface coating structure for extending the service life of a screen according to claim 1, characterized in that: The notch structure is a square hole (42) located at the center of the reinforced PI film (4) and facing the pattern area (21). The square hole (42) includes two short sides (421) parallel to the wide sides (24). The two short sides (421) are located between the two wide sides (24). A reinforcement area (43) is provided on the side opposite to the short sides (421). A plurality of printing grooves (44) for printing electrode grid lines are provided in the reinforcement area (43).

4. The surface coating structure for extending the service life of a screen according to claim 1, characterized in that: The notch structure comprises a plurality of grid line grooves (45) formed on the reinforced PI film (4), wherein the grid line grooves (45) are directly opposite to the electrode grid lines on the surface of the battery cell (3).

5. The surface coating structure for enhancing the service life of a screen according to any one of claims 1 to 4, characterized in that: The side of the printed PI film (6) facing the battery cell is covered with a protective PI film (5), and the protective PI film (5) is provided with a protective notch for exposing the pattern opening (22).

6. The surface coating structure for extending the service life of a screen according to claim 5, characterized in that: The protective gap is a protective hole (51) located at the center of the protective PI film (5) and facing the pattern area (21), and the pattern area (21) is located in the protective hole (51).

7. The surface coating structure for extending the service life of a screen according to claim 5, characterized in that: The protective gap is a protective hole (52) located at the center of the protective PI film (5) and facing the pattern area (21); the square hole (42) includes two protective edges (521) parallel to the wide edges (24); the two protective edges (521) are located between the two wide edges (24); a protective area (53) is provided on the side opposite to the protective edge (521); and a plurality of silk screen grooves (54) for printing electrode grid lines are provided in the protective area (53).

8. The surface coating structure for extending the service life of a screen according to claim 5, characterized in that: The protective gap comprises a plurality of grid line through grooves (55) formed on the protective PI film (5), and the grid line through grooves (55) are directly opposite to the electrode grid lines on the surface of the battery cell (3).

9. A surface coating process for increasing the service life of a screen, used for manufacturing the surface coating structure for increasing the service life of a screen as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Cover the metal mesh S surface with a reinforced PI film; S2, cutting a notch structure on the reinforced PI film; S3, removing the excess reinforced PI film cut; S4, compounding the reinforced PI film onto the S surface of the metal mesh; S5. Turn the metal mesh over so that the P side faces upwards and attach a protective PI film to the P side. S6. Cut a protective notch on the protective PI film; S7, removing the excess protective PI film cut; S8. Composite the protective PI film, the metal mesh and the reinforced PI film.

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