Offset metal mesh screen printing plate

Abstract

The utility model discloses an offset metal mesh silk screen printing plate which comprises a screen frame, a metal mesh and a printing plate wire groove, the metal mesh is tensioned on the screen frame through a tensioning wire mesh, the printing plate wire groove is formed in the metal mesh, the metal mesh is formed by interweaving variable-pitch silk threads and equidistant silk threads in a crossed mode, and the printing plate wire groove is formed in the printing plate wire groove. The printing plate wire groove is located between two adjacent variable-pitch silk threads, and one groove side or two groove sides of at least one printing plate wire groove are provided with two variable-pitch silk threads which are close to each other. The two variable-pitch silk threads which are close to each other comprise offset silk threads and weaving silk threads, and the offset silk threads are formed by offsetting the weaving silk threads. And the printing plate wire groove is parallel to the variable-pitch silk thread. The diameter of the variable-pitch silk threads and the diameter of the equidistant silk threads range from 6 micrometers to 10 micrometers. The screen printing plate not only can prevent silk threads from crossing a screen to form a current screen printing slot area, but also can ensure the tensile strength of the silk screen of the screen printing plate.

Description

Technical Field

[0001] The utility model relates to a solar photovoltaic cell printing screen, in particular to a solar photovoltaic cell sheet printing screen which can achieve knot-free printing by offsetting screen wires. Background Art

[0002] The screen is an important tool for printing solar cell electrodes. The slurry is poured onto the screen and moved on the screen with a scraper so that the slurry is squeezed through the mesh holes on the screen onto the solar cell, forming a corresponding pattern on the solar cell to form the electrode of the solar cell.

[0003] Since the printing screen uses a metal woven mesh, there are overlapping intersections at the intersection of the warp and weft of the metal wire mesh, forming knots. The mesh knots of the screen are relatively obstructive to ink or slurry, reducing the ink permeability of the printing screen. In order to eliminate the negative impact of the knots as much as possible, the current solar cell screens mostly remove the metal wires in the warp or weft direction of the printed graphics, and arrange the fine grid graphics in the grid without the knots when making the graphics. Although this approach improves the printability of the fine grid, the process of removing the steel wire requires about 20 to 30 minutes of cutting using a laser machine to cut the steel wire, and then wash the steel wire residues through water washing and other steps to ensure that the steel wires have been removed. At the same time, the screen must be inspected to prevent the residue from being completely removed, resulting in the scrapping of the screen; at the same time, during the laser cutting process, due to equipment stability, incorrect parameter settings, irregular shapes of the grids in the mesh, etc., the laser may also cut the steel wires in another direction, causing the screen to break.

[0004] Furthermore, in order to ensure the photosensitive area on the surface of the photovoltaic cell, it is hoped that the width of the printed conductive grid line is as thin as possible. At present, the wire diameter of high-quality and high-precision printing screens has reached less than 10μm. Under such precise mesh conditions, the method of cutting steel wires by laser will, on the one hand, affect the tensile strength of the screen due to the reduction in the number of steel wires. During repeated printing, it is easy to cause cracks and breakage of the screen, resulting in the scrapping of the screen, shortening the service life of the screen and increasing printing costs. On the other hand, ultra-fine and ultra-fine metal wire meshes increase the difficulty of laser cutting, and also increase the risk of accidental cutting and the difficulty of removing broken wires. Utility Model Content

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the utility model is to provide a biased metal screen printing screen, which can avoid the appearance of cross-thread knots in the screen printing groove area and ensure the tension strength of the screen mesh.

[0006] In order to solve the above technical problems, the utility model discloses an offset metal mesh printing screen, comprising a screen frame, a metal wire mesh and a printing plate wire groove, wherein the metal wire mesh is stretched on the screen frame by a tensioning wire mesh, and the printing plate wire groove is arranged on the metal wire mesh, and the metal wire mesh is formed by cross-weaving variable-pitch wires and equidistant wires, and the printing plate wire groove is located between two adjacent variable-pitch wires, and at least one of the printing plate wire grooves has two variable-pitch wires close to each other on one groove side or both groove sides.

[0007] In the above structure, since the printing plate line groove is located between two adjacent variable-pitch silk threads, it is ensured that the printing plate line groove is always located between two warps or wefts, forming a knot-free printing plate structure, and there are no warp and weft intersection nodes in the printing plate line groove, reducing the printing resistance to the printing slurry, and ensuring the ink permeability and printing quality of the printing screen; and two variable-pitch silk threads close to each other are arranged on the groove side of the printing plate line groove, so that there is no need to remove the warp or weft threads forming the cross-pitch by laser cutting, and no cut wire residue will be formed to affect the printing quality, and there will be no screen breakage caused by the laser cutting of adjacent wires by mistake; in particular, this structure can form variable-pitch silk threads close to each other by offsetting specific silk threads of the equidistant woven mesh, and does not reduce the number of mesh wires of the mesh, thereby ensuring sufficient tension strength of the screen surface, and is particularly suitable for printing screens with extremely fine and ultra-fine mesh wires.

[0008] In a preferred embodiment of the utility model, the two variable-pitch wires close to each other include an offset wire and a braided wire, the offset wire is formed by offsetting the braided wire, and the braided wires are arranged equidistantly from each other. The printing plate wire groove is parallel to the variable-pitch wire. The wire diameters of the variable-pitch wire and the equidistant wire are 6μm-10μm. This structure ensures that there are no knots formed by the intersection of warp and weft wires in the printing plate wire groove, and can keep the tension strength of the metal wire mesh unchanged; it is particularly suitable for screen meshes with extremely fine or ultra-fine wires.

[0009] In a preferred embodiment of the utility model, the scraping side of the metal screen is coated with a scraping side film layer, a plurality of scraping side line grooves are arranged on the scraping side film layer, the printing side of the metal screen is coated with a printing side film layer, a plurality of printing side line grooves are arranged on the printing side film layer, and the slot width of the scraping side line groove is greater than the slot width of the printing side line groove. The scraping side film layer and the printing side film layer are polymer film adhesive layers and / or photosensitive adhesive coating layers. A stepped opening material storage structure is formed, and the silver paste in the stepped opening slot can be directly scraped out of the printing film line slot, thereby reducing the penetration barrier of the screen to the printing paste. At the same time, the scraper can generate a certain printing extrusion force on the paste in the stepped opening slot during scraping, prompting the paste in the plate line slot to be transferred to the printing substrate.

[0010] In a preferred embodiment of the utility model, the printing side of the metal screen is coated with an intermediate film layer, a printing side film layer is coated on the intermediate film layer, a plurality of intermediate film layer line grooves are arranged on the intermediate film layer, a plurality of printing side line grooves are arranged on the printing side film layer, and the slot width of the intermediate film layer line groove is greater than the slot width of the printing side line groove. The intermediate film layer and the printing side film layer are polymer film adhesive layers and / or photosensitive adhesive coating layers. A stepped opening material storage structure is formed, and the silver paste in the stepped opening groove can be directly scraped out of the printing film line groove, thereby reducing the penetration barrier of the screen to the printing paste. At the same time, the scraper can generate a certain printing extrusion force on the paste in the stepped opening groove during scraping, prompting the paste in the printing plate line groove to be transferred to the printing substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The offset metal screen printing screen of the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0012] Figure 1 It is a structural schematic diagram of a specific implementation method of the offset metal screen printing screen of the utility model;

[0013] Figure 2 yes Figure 1 A partial enlarged view of the metal wire mesh surface in the middle part I;

[0014] Figure 3 yes Figure 1 A magnified view of a specific structure of a metal wire mesh cross section;

[0015] Figure 4 yes Figure 1 Another specific structure enlarged view of the metal wire mesh cross section.

[0016] In the figure, 1 is a screen frame, 2 is a tensioned wire mesh, 3 is a metal wire mesh, 4 is a printing plate wire groove, 5 is a variable-pitch wire, 51 is a biased wire, 52 is a braided wire, 6 is an equidistant wire, 7 is a scraping side film layer, 8 is a pasting side film layer, 9 is a scraping side wire groove, 10 is a pasting side wire groove, 11 is an intermediate film layer, and 12 is an intermediate film layer wire groove. DETAILED DESCRIPTION

[0017] like Figure 1 The offset metal screen printing screen shown includes a screen frame 1, which is an aluminum square frame member in the shape of a U-shaped character. A stainless steel metal screen 3 is stretched at the center of the screen frame 1. The metal screen 3 is bonded with a stretched wire screen 2 on the four sides. The stretched wire screen 2 is a polyester mesh. The bonding ends of the stretched wire screen 2 are fixedly bonded to the bottom surface of the screen frame 1. A printing plate line groove 4 for printing the conductive grid line of the battery cell is set on the metal screen 3.

[0018] like Figure 2As shown, the metal wire mesh 3 is formed by interlacing and weaving variable-pitch wires 5 and equidistant wires 6 perpendicularly to each other; the variable-pitch wires 5 and equidistant wires 6 are stainless steel wires with a wire diameter between 6 μm and 10 μm, or nickel wires. Figure 2 In the figure, the weft-direction silk threads are equidistant silk threads 6, and the warp-direction silk threads are variable-distance silk threads 5. The variable-distance silk threads 5 include braided silk threads 52 and biased silk threads 51, and the biased silk threads 51 are formed by biasing and shifting the braided silk threads 52; when a certain warp silk thread (as shown by the dotted line in the figure) happens to be located at the position of the printing plate wire groove 4 and crosses with the weft-direction equidistant silk threads 6 to form a net knot, it is necessary to use an offset comb with a number of comb needles to shift the warp silk thread to be close to another warp silk thread to form a parallel wire structure, and the two variable-distance silk threads 5 close to each other include a biased silk thread 51 formed by shifting, and the other is the braided silk thread 52 when the screen is weaved, and the braided silk thread 52 when weaving is set at an equal distance. The printing plate wire groove 4 is parallel to the variable-distance silk thread 5.

[0019] like Figure 3 As shown, the scraping side G surface of the metal screen 3 is coated with a scraping side film layer 7, which is formed by coating and photosensitizing a photosensitive latex. The outer surface of the scraping side film layer 7 is the scraping surface, and the scraper is in direct contact with the scraping surface during scraping. A number of scraping side line grooves 9 are designed on the scraping side film layer 7 according to the printing pattern, and the cross section of the scraping side line grooves 9 is a rectangular through groove. The lower surface of the printing side T of the metal screen 3 is coated with a pasting side film layer 8, which is formed by pasting a polymer film such as PET, PE, PI, PU, ​​PVC, PS, etc., and a number of pasting side line grooves 10 are also designed on the pasting side film layer 8 according to the printing pattern. The center lines of the corresponding scraping side grooves 9 and the pasting side grooves 10 are located on the same straight line, and the groove width of the scraping side grooves 9 is greater than the groove width of the pasting side grooves 10, thereby forming a plate groove 4 with a stepped cross-section, which is beneficial to improving the ink permeability of printing, improving printing quality, and more beneficial to improving the aspect ratio of the printed electrode paste, which is beneficial to reducing the shading area of ​​the printed grid line and can effectively reduce the consumption of printing paste.

[0020] like Figure 4 As shown, the printing side (T) of the metal screen 3 is coated with an intermediate film layer 11, which is formed by coating and photosensitizing a photosensitive emulsion. The intermediate film layer 11 is designed with a plurality of intermediate film layer line grooves 12 according to the printing pattern, and the cross section of the intermediate film layer line grooves 12 is a rectangular through groove. The intermediate film layer 11 is coated with a printing side film layer 8, which is formed by pasting a polymer film such as PET, PE, PI, PU, ​​PVC, PS, etc., and a plurality of printing side line grooves 10 are arranged on the printing side film layer 8, and the slot width of the intermediate film layer line groove 12 is greater than the slot width of the printing side line groove 10, thereby forming a plate line groove 4 with a stepped cross section. The intermediate film layer 11 and the printing side film layer 8 can be a polymer film pasting layer or a photosensitive adhesive coating layer.

[0021] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principle and practical application of the utility model, so that technicians in the relevant technical field can understand and use the utility model well. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the utility model.

Claims

1. An offset metal screen printing screen, comprising a screen frame (1), a metal screen (3) and a printing plate wire slot (4), wherein the metal screen (3) is stretched on the screen frame (1) by a stretching wire mesh (2), and the printing plate wire slot (4) is arranged on the metal screen (3), characterized in that: The metal wire mesh (3) is formed by interlacing and weaving variable-distance wires (5) and equidistant wires (6); the printing plate wire groove (4) is located between two adjacent variable-distance wires (5); and at least one of the printing plate wire grooves (4) is provided with two variable-distance wires (5) close to each other on one groove side or both groove sides.

2. The offset metal screen printing screen according to claim 1, characterized in that: The two variable-distance wires (5) close to each other include a bias wire (51) and a braided wire (52), wherein the bias wire (51) is formed by offsetting the braided wire, and the braided wires (52) are arranged at equal distances from each other.

3. The offset metal screen printing screen according to claim 1 or 2, characterized in that: The printing plate wire groove (4) is parallel to the variable-pitch wire (5).

4. The offset metal screen printing screen according to claim 1 or 2, characterized in that: The wire diameters of the variable-distance wires (5) and the equidistant wires (6) are 6 μm to 10 μm.

5. The offset metal screen printing screen according to claim 1, characterized in that: The scraping side (G) of the metal wire mesh (3) is coated with a scraping side film layer (7), and a plurality of scraping side line grooves (9) are arranged on the scraping side film layer (7); the printing side (T) of the metal wire mesh (3) is coated with a printing side film layer (8), and a plurality of printing side line grooves (10) are arranged on the printing side film layer (8); the slot width of the scraping side line groove (9) is greater than the slot width of the printing side line groove (10).

6. The offset metal screen printing screen according to claim 5, characterized in that: The scraping side film layer (7) and the pasting side film layer (8) are polymer film adhesive layers and / or photosensitive adhesive coating layers.

7. The offset metal screen printing screen according to claim 1, characterized in that: The printing side (T) of the metal wire mesh (3) is coated with an intermediate film layer (11), a printing side film layer (8) is coated on the intermediate film layer (11), a plurality of intermediate film layer line grooves (12) are arranged on the intermediate film layer (11), a plurality of printing side line grooves (10) are arranged on the printing side film layer (8), and the slot width of the intermediate film layer line grooves (12) is greater than the slot width of the printing side line grooves (10).

8. The offset metal screen printing screen according to claim 7, characterized in that: The intermediate film layer (11) and the printing side film layer (8) are polymer film adhesive layers and / or photosensitive adhesive coating layers.

Images