A novel primary grid plate PI adhesive tape

Abstract

The utility model discloses a novel main grid screen plate PI adhesive tape, include: annular DT, the continuous distribution of the periphery of surrounding main grid line printing area is closed annular, the PI adhesive tape between grid lines is constituted by at least three equidistance parallel arrangement between adjacent main grid line structure of strip shape, the junction PI adhesive tape is set up in the junction area of annular DT and the PI adhesive tape between grid lines. Three through laser cutting PI film integrated molding, form seamless whole structure of linking, then after one hot pressing compound to screen base material. The utility model discloses laser cutting combines hot pressing forming technology and makes integrated PI adhesive tape structure, has simplified production technology, has shortened the cycle of making a plate, makes the comprehensive cost of screen printing production decline, integrated PI adhesive tape structure not only reduces the risk of explosion edition, also has improved screen printing strength and printing life. The utility model is suitable for the batch production of main grid screen plate, provides the solution with economical and reliable for photovoltaic manufacturing.

Description

Technical Field

[0001] This utility model relates to the field of screen printing technology, and in particular to a novel main grid PI tape. Background Technology

[0002] In the manufacturing process of photovoltaic cells, the main grid screen is a crucial printing tool, and its performance directly affects the conductivity and conversion efficiency of the cell. Currently, the main grid screens used in the domestic photovoltaic industry require PI tape to be applied between the grid lines on the printed surface after hot-pressing the PI film. This process is not only time-consuming and labor-intensive, but also prone to uneven gaps or overlaps in the tape placement due to the limitations of manual application. More seriously, in traditional processes, operators need to repeatedly touch the screen surface with their fingers to apply the tape, which easily damages the screen and significantly increases the risk of screen breakage. Existing technologies require step-by-step completion of PI film hot pressing, annular DT hot pressing, and PI tape application between grid lines, resulting in long screen production cycles and low production efficiency, making it difficult to meet the needs of large-scale mass production in the photovoltaic industry.

[0003] Chinese Patent Publication No. CN109130454A discloses a method for applying tape to a screen printing stencil and the screen printing stencil itself. Through a staged and area-specific precise tape application process, thickened tape is used at the edges of the stencil's graphic area to prevent damage from silicon wafer burrs. Angled tape is applied at the four corners to address chamfer wear, and silver-coated tape with limiting holes is placed between the stencil frame and the graphic area to delay tension attenuation. A symmetrical application scheme of dual explosion-proof tape in the main / fine grid direction, combined with the synergistic protection of wear-resistant tape on the squeegee surface, forms a multi-layered protective system.

[0004] The existing tape application method relies on step-by-step manual operation, which requires applying five different functional tapes in sequence and applying them on both sides. This manual step-by-step application increases the risk of the tape bursting when the fingers touch the plate surface multiple times, resulting in a long plate-making cycle and low production efficiency. At the same time, uneven gaps and tape overlap are prone to occur at the application points.

[0005] Therefore, it is necessary to provide a new type of main grid PI tape to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention overcomes the shortcomings of existing technologies and provides a novel PI tape for main grid screen printing. It aims to solve the problems in existing technologies, such as the tendency for manual, step-by-step application of PI tape between grid lines to cause printing plate bursts, long plate-making cycles, low production efficiency, uneven gaps, and tape overlap at the bonding positions.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a novel main grid screen PI tape, comprising: an annular DT, continuously distributed around the periphery of the main grid line printing area, forming a closed loop; a grid line PI tape, composed of at least three strip-shaped structures arranged parallel to each other at equal intervals between adjacent main grid lines; and a connecting PI tape, disposed at the junction area of ​​the annular DT and the grid line PI tape.

[0008] The annular DT, the PI tape between the grid lines, and the PI tape at the connection point are an integrated structure with no gaps or overlaps at the connection point.

[0009] In a preferred embodiment of this invention, the width of the annular DT is 3-10 mm and the thickness is 10-20 μm.

[0010] In a preferred embodiment of this invention, the distance between the inner edge of the annular DT and the outermost main grid line is controlled within the range of 0.5mm ± 0.05mm.

[0011] In a preferred embodiment of this invention, the width of the PI tape between the grid lines is 3-10 mm and the thickness is 10-20 μm.

[0012] In a preferred embodiment of this invention, the vertical spacing between the PI tapes between the grid lines is consistent with the spacing between the main grid lines, and the tolerance is controlled within ±0.1mm.

[0013] In a preferred embodiment of this utility model, the overlap deviation between the center line of the PI tape between the grid lines and the center line of the corresponding grid line gap is ≤0.05mm, which is used to isolate the printing areas of adjacent main grid lines to eliminate the risk of short circuit due to slurry bridging.

[0014] In a preferred embodiment of this utility model, the width of the PI tape at the connection point is 3-10mm and the thickness is 10-20μm.

[0015] In a preferred embodiment of this utility model, the corner area of ​​the PI tape at the connection point adopts a rounded transition design with an arc radius R = 0.5-2mm.

[0016] In a preferred embodiment of this invention, the PI tape is made of polyimide.

[0017] In a preferred embodiment of this invention, the roughness Ra of the edge cutting surface of the integrated structure is ≤0.5μm.

[0018] This utility model solves the defects existing in the background technology, and has the following beneficial effects:

[0019] (1) This utility model discloses a novel main grid PI tape, which uses laser cutting technology to cut the annular DT, the PI tape between the grid lines and the PI tape at the connection point into a seamless integral structure in one go, with no gaps or overlaps at the connection point; the radius of curvature R of the PI tape at the connection point is 0.5-2mm, which effectively disperses stress concentration and overcomes the technical problem of easy cracking at traditional right-angle connections; it eliminates the problem of uneven gaps and tape overlap caused by traditional manual step-by-step bonding, avoids short circuits caused by ink leakage, and reduces the risk of plate bursting. Compared with the prior art that requires step-by-step tape application and relies on manual alignment accuracy, the integrated structure of this utility model reduces the complexity of operation and improves the accuracy of printing position.

[0020] (2) In this invention, the thickness of the annular DT, the PI tape between the grid lines, and the PI tape at the connection points is uniformly 10-20μm, and the width is 3-10mm. This one-time cutting and forming reduces the generation of edge waste and lowers the overall cost of the screen printing plate. Compared with the prior art, which requires the consumption of multiple layers of heterogeneous materials such as silver dragon tape and explosion-proof tape, the PI tape structure in this invention is compatible with automated production lines and meets the needs of GW-level photovoltaic production capacity.

[0021] (3) The circular DT of this utility model adopts a closed ring structure with a width of 3-10mm and the distance between the inner edge and the outermost grid line is accurate to 0.5mm±0.05mm; the closed ring design forms a continuous mechanical constraint boundary, which locks the printing boundary of the paste within the range of ±0.1mm, reducing the risk of paste overflow at the edge of the screen and the expansion of the graphic area; compared with the prior art, which requires manual control of 200-500μm spacing and beveled tape, the circular DT of this utility model achieves automatic matching with millimeter-level precision through structural integration. The closed ring structure improves the screen's resistance to shear deformation, improves the uniformity of printing pressure distribution, and avoids edge and corner bursting.

[0022] (4) In this invention, the PI tape between the grid lines is arranged parallel to the main grid lines, with a centerline overlap deviation of ≤0.05mm and a width equal to that of the annular DT. The equal width design matches the optimized laser cutting path, and the tape gap is completely synchronized with the grid line spacing, forming an equal stress bearing unit. Compared with the prior art, which requires the application of explosion-proof tape in the main / fine grid direction and lacks a width coordination design, this invention eliminates directional differences through structural symmetry, reducing the risk of grid line breakage due to local stress concentration. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0024] Figure 1 This is a schematic diagram of the structure of the main grid PI tape of this utility model;

[0025] In the diagram: 1. Circular DT; 2. PI tape between grid lines; 3. Main grid line; 4. PI tape at the connection point. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0027] like Figure 1 As shown, a novel main grid PI tape includes: annular DT1, PI tape between grid lines 2, and PI tape at the connection point 4.

[0028] PI films with a thickness of 10-20 μm, a coefficient of thermal expansion ≤20 ppm / ℃, and a tensile strength ≥200 MPa are selected as the basic raw material. A laser cutting system with a wavelength range of 355-1064 nm, a power of 10-50 W, and a cutting accuracy of ±5 μm is used to precisely cut the PI film, forming an integrated structure including annular DT1, inter-line PI tape 2, and connecting PI tape 4. The edge cut surface roughness Ra ≤0.5 μm, with no burrs or slag residue. Among them:

[0029] The DT1 ring is designed as a closed ring structure with a width of 3-10mm and a thickness of 10-20μm. It is set along the outer perimeter of the screen, and the distance between the inner edge and the outermost grid line is precisely controlled within 0.5mm±0.05mm, forming a continuous mechanical constraint boundary. This locks the printing boundary of the ink within the range of ±0.1mm, reducing the risk of ink overflow at the edge of the screen and the expansion of the graphic area.

[0030] Fifteen PI tapes 2 are installed between the grid lines, with a width of 3-10mm and a thickness of 10-20μm, and are arranged parallel to the main grid lines 3. The vertical spacing between the PI tapes 2 between the grid lines is consistent with the spacing between the main grid lines 3, with the tolerance controlled within ±0.1mm, and the centerline overlap deviation controlled within 0.05mm, so as to eliminate the risk of slurry bridging and short circuit.

[0031] The PI tape 4 at the connection point has a width of 3-10mm and a thickness of 10-20μm. It uses an arc transition with R=0.5-2mm to connect the annular DT1 and the PI tape 2 between the grid lines. The width gradually changes, and there are no gaps or overlaps at the connection point, which ensures uniform stress distribution and overcomes the technical problem of easy cracking at traditional right-angle connections.

[0032] The laser-cut integrated PI tape of the main grid screen is precisely aligned onto the surface of the screen substrate graphic and then hot-pressed onto the screen substrate at 180-250℃ and 0.5-1.2MPa for 30-90 seconds. This single hot-pressing process avoids uneven gaps and tape overlaps that can occur with multiple manual laminations, reducing the risk of screen breakage and enhancing screen strength.

[0033] In use, the annular DT1 serves as a key support structure for the main grid screen. Its closed-loop design forms a continuous stress buffer zone at the edge of the screen, while the precise spacing of 0.5mm ± 0.05mm at its inner edge creates a physical barrier for ink flow, effectively suppressing ink overflow during printing. The PI tapes 2 between the grid lines are arranged in an equidistant parallel array, with a centerline deviation ≤ 0.05mm from the centerline of the grid line gap. Their width is strictly equal to that of the annular DT1. A micron-level precise gap is formed between the PI tapes 2 and the ink, allowing the ink to pass smoothly while preventing ink penetration between adjacent grid lines, reducing the risk of ink bridging defects. The arc-shaped transition design of the PI tape 4 at the connection point achieves a seamless connection and smooth transition between the annular DT1 and the PI tapes 2 between the grid lines. This not only avoids stress concentration but, more importantly, forms a smooth ink guide surface, making the ink flow rate distribution more uniform at the corners. The synergistic effect of the three components produces significant technical results. The annular DT1 provides overall stability, the PI tape 2 between the grid lines ensures printing accuracy, and the PI tape 4 at the joint optimizes the slurry flow characteristics.

[0034] Based on the preferred embodiments of this utility model described above, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A novel main grid PI tape, characterized in that, include: The ring-shaped DT(1) is continuously distributed around the periphery of the printing area of ​​the main grid line (3), forming a closed ring. The inter-grid PI tape (2) is composed of at least three strip structures that are equally spaced and parallel between adjacent main grid lines (3); The PI tape (4) at the connection point is set in the junction area of ​​the annular DT (1) and the PI tape (2) between the grid lines; The annular DT (1), the inter-grid PI tape (2), and the connecting PI tape (4) are an integrated structure with no gaps or overlaps at the connection.

2. The novel main grid PI tape according to claim 1, characterized in that: The annular DT(1) has a width of 3-10 mm and a thickness of 10-20 μm.

3. The novel main grid PI tape according to claim 1, characterized in that: The distance between the inner edge of the annular DT (1) and the outermost main gate line (3) is controlled within the range of 0.5mm ± 0.05mm.

4. The novel main grid PI tape according to claim 1, characterized in that: The width of the PI tape (2) between the grid lines is 3-10 mm and the thickness is 10-20 μm.

5. The novel main grid PI tape according to claim 1, characterized in that: The vertical spacing between the PI tapes (2) between the grid lines is consistent with the spacing between the main grid lines (3), and the tolerance is controlled within ±0.1mm.

6. The novel main grid PI tape according to claim 1, characterized in that: The centerline of the inter-grid PI tape (2) has a deviation of ≤0.05mm from the centerline of the corresponding grid gap, and is used to isolate the printing area of ​​adjacent main grid lines (3) to eliminate the risk of slurry bridging and short circuit.

7. The novel main grid PI tape according to claim 1, characterized in that: The width of the PI tape (4) at the connection point is 3-10mm and the thickness is 10-20μm.

8. The novel main grid PI tape according to claim 1, characterized in that: The corner area of ​​the PI tape (4) at the connection point adopts a rounded transition design with an arc radius R = 0.5-2mm.

9. The novel main grid PI tape according to claim 1, characterized in that: The PI tape is made of polyimide.

10. The novel main grid PI tape according to claim 1, characterized in that: The edge cutting surface roughness Ra of the integrated structure is ≤0.5μm.

Images