Grid line and preparation method thereof

Abstract

The invention relates to the field of solar cell preparation, in particular to a grid line and a preparation method thereof. The grid line preparation method provided by the invention comprises the following steps: performing first jet printing on the surface of a metal seed layer to obtain a plurality of first jet printing belts; the area between the adjacent first jet printing belts on the surface of the metal seed layer is an initial blank area; performing second jet printing to obtain a plurality of second jet printing belts; the second jet printing belt covers part of the initial blank area; the second jet printing belt covers part of the first jet printing belt; the first jet printing belt and the second jet printing belt covering the first jet printing belt form a composite jet printing belt, and a blank area is obtained; repeating the steps for N times to obtain a target blank area; and depositing metal to form a metal coating to obtain the grid line. The method provided by the invention has the advantages that the line width of the grid line is adjusted, the line width of the prepared grid line is relatively narrow, the material utilization rate in the preparation process is relatively high, and the production cost is relatively low.

Description

Technical Field

[0001] The invention relates to the field of solar cell preparation, and in particular to a grid line and a preparation method thereof. Background Art

[0002] At present, in the photovoltaic field, grid lines are prepared by patterning processes, which mainly include screen printing and laser ablation. Screen printing is limited in use due to the following problems: (1) The material utilization rate is relatively low and the cost is high. The materials used for grid lines are mostly precious metal pastes with high value; (2) In the industrialization process, high-precision screen printing plates are expensive and have a short service life; (3) If products with different line widths are produced, screens with different apertures are required, which is costly. For the laser ablation method, its equipment is expensive, the material utilization rate is low, and the grid line accuracy is limited by the focusing size of the laser, making it difficult to form grid lines with a line width less than 35μm.

[0003] In the prior art, there is an urgent need to provide a method for preparing gate lines that can adjust the width of the gate lines, has a narrower width of the prepared gate lines, has a higher material utilization rate during the preparation process, and has a lower production cost. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that there is no method for preparing gate lines that can adjust the gate line width, obtain a narrow gate line width, have a high material utilization rate during the preparation process, and have a low production cost, thereby providing a gate line and a preparation method thereof.

[0005] The present invention provides a method for preparing a gate line, comprising the following steps:

[0006] (1) forming a metal seed layer on a surface of a substrate layer; the surface of the metal seed layer has a first direction and a second direction perpendicular to each other;

[0007] (2) performing a first printing on the surface of the metal seed layer along a second direction through a plurality of first nozzles with a center spacing of T0 to obtain a plurality of first printing strips; the diameter of the ink droplets of the first printing is The plurality of first spray holes are arranged parallel to the first direction; the area between adjacent first spray-printed bands on the surface of the metal seed layer is an initial blank area;

[0008] (3) performing a second printing along a second direction through a plurality of second nozzles with a center spacing of T0 to obtain a plurality of second printing strips; wherein the plurality of second nozzles are arranged parallel to the first direction and correspond to the plurality of first nozzles in step (2); and the diameter of the ink droplets of the second printing is The second printing belt covers part of the initial blank area formed in step (2); the second printing belt covers part of the first printing belt; the first printing belt and the second printing belt covering it form a composite printing belt; in this step, the area between adjacent composite printing belts on the surface of the metal seed layer is the blank area;

[0009] (4) Repeat step (3) N times, wherein the nozzle used in each printing is arranged parallel to the first direction, and the diameter of the ink droplets printed is less than or equal to the diameter of the ink droplets printed in the previous printing; the printing belt formed by each printing covers part of the composite printing belt obtained by the previous printing, and covers part of the blank area obtained by the previous printing. After repeating step (3) N times, the area between adjacent composite printing belts on the surface of the metal seed layer is the target blank area; N is an integer greater than or equal to zero;

[0010] (5) Depositing metal on the target blank area to form a metal layer, thereby obtaining the gate line.

[0011] Preferably, in step (2), the width of the initial blank area is

[0012] Preferably, in step (3), the second printing tape covers part of the initial blank area, and the width of the initial blank area covered is T1. and The second printing belt covers part of the first printing belt, and the width of the first printing belt covered is The width of the blank area obtained in step (3) is

[0013] Preferably, in step (4), when the i-th repetition of step (3) is repeated N times, the printed band formed by the printing covers part of the blank area obtained by the previous printing, and the width of the blank area obtained by the previous printing is T (i) ; i is an integer between 0 and N; after repeating step (3) N times, the width of the target blank area is

[0014] It can be understood that in step (3), the distance between the second nozzle and the corresponding first nozzle in the first direction is Δx1, and the second printing band covers part of the initial blank area, and the width of the initial blank area covered is The width of the blank area obtained in step (3) is

[0015] In step (4), the nozzle diameter used for printing in the i-th repetition of step (3) is And compared with the previous corresponding nozzle hole spacing in the first direction is Δx (i) The formed printing belt covers part of the blank area obtained by the previous printing. The width of the blank area obtained by the previous printing is i is an integer between 0 and N; when i is 0, step (3) is not repeated. Δx (0) =0; the width of the blank area obtained in step (4) is

[0016] Preferably, the substrate layer is a silicon wafer.

[0017] Preferably, the silicon wafer is a bare silicon wafer for a solar cell.

[0018] Preferably, in step (5), the method of depositing the metal is selected from electroplating, chemical plating, physical vapor deposition or chemical vapor deposition.

[0019] Preferably, after forming the gate lines, the method further includes removing the printed material on the surface of the metal seed layer and the metal seed layer not covered by the gate lines in sequence.

[0020] Preferably, the printing material used in the printing is selected from a hot melt material, wherein the hot melt material has fluidity at a temperature greater than or equal to 50°C and a viscosity of 0.1 mPa·S to 20 mPa·S; and when the temperature is less than or equal to 25°C, the hot melt material is solid or fluid, and when it is a fluid, the viscosity of the hot melt material is greater than 10000 mPa·S;

[0021] Preferably, the printing material used in the printing is selected from one or more of acrylate, rosin ester resin, C11-C22 alkyl acid, polypropylene wax, microcrystalline wax, polyethylene wax, and ethylene-vinyl acetate copolymer wax.

[0022] Preferably, the ink droplet diameter in step (3) is the same as the ink droplet diameter in step (2); the second nozzle in step (3) is the nozzle obtained by translating the first nozzle in step (2) along the first direction; and / or,

[0023] The ink droplet diameter in step (4) is the same as the ink droplet diameter in step (2); the nozzle in step (4) is the nozzle obtained by translating the first nozzle in step (2) along the first direction.

[0024] Preferably, the second spray hole in step (3) is a spray hole that is staggered with the first spray hole in step (2); and / or,

[0025] The spray hole in step (4) is a spray hole that is offset from the first spray hole in step (2).

[0026] Preferably, in step (3), and / or,

[0027] In step (4), T (i) Less than or equal to 0.85 times the diameter of the ink droplet printed this time.

[0028] The present invention also provides a gate line, which is prepared by the above-mentioned preparation method.

[0029] The present invention further provides a solar cell, comprising a grid line prepared by the above-mentioned preparation method or the above-mentioned grid line.

[0030] The technical solution of the present invention has the following advantages:

[0031] The method for preparing a gate line provided by the present invention comprises the following steps: (1) forming a metal seed layer on the surface of a substrate layer; the surface of the metal seed layer has a first direction and a second direction perpendicular to each other; (2) performing a first spray printing on the surface of the metal seed layer along the second direction through a plurality of first spray holes with a center spacing of T0 to obtain a plurality of first spray printing bands; the diameter of the ink droplets of the first spray printing is wherein the plurality of first nozzles are arranged parallel to the first direction; the area between the adjacent first printing strips on the surface of the metal seed layer is the initial blank area; (3) a second printing is performed along the second direction through a plurality of second nozzles with a center spacing of T0 to obtain a plurality of second printing strips; wherein the plurality of second nozzles are arranged parallel to the first direction and correspond to the plurality of first nozzles in step (2); the ink droplet diameter of the second printing is The second printing belt covers part of the initial blank area formed in step (2); the second printing belt covers part of the first printing belt; the first printing belt and the second printing belt covering it form a composite printing belt; in this step, the area between adjacent composite printing belts on the surface of the metal seed layer is the blank area; (4) repeating step (3) N times, the nozzle used for each printing is set parallel to the first direction, and the diameter of the printed ink droplets is less than or equal to the diameter of the ink droplets of the previous printing; the printing belt formed by each printing covers part of the composite printing belt obtained by the previous printing, and covers part of the blank area obtained by the previous printing. After repeating step (3) N times, the area between adjacent composite printing belts on the surface of the metal seed layer is the target blank area; N is an integer greater than or equal to zero; (5) depositing metal on the target blank area to form a metal layer, thereby obtaining the gate line.

[0032] In the present invention, an initial blank area is formed on the surface of the metal seed layer by the first printing; then, a part of the initial blank area is gradually covered by the printing of step (3) and step (4), so that the width of the blank area is gradually reduced, and then metal is deposited to form a grid line; by adopting the technical scheme of the present invention, the width of the blank area between adjacent composite printing belts on the surface of the metal seed layer can be adjusted only by multiple printings; and the width of the blank area can be gradually reduced by the above adjustment, and a grid line with an extremely narrow line width can be prepared according to production requirements; and when facing requirements for grid lines of different widths, the equipment adjustment cost is low, thereby reducing production costs; and because the width of the blank area is adjusted only by printing, there is no need to remove the printing belt additionally, thereby improving the utilization rate of materials; in summary, the method provided by the present invention can take into account the adjustment of the grid line width size, the prepared grid line width is narrow, the material utilization rate is high during the preparation process, and the production cost is low;

[0033] Furthermore, in the technical solution of the present invention, by determining the center distance of the nozzle holes for printing, multiple printings are used to gradually cover the initial blank area, and the diameter of the printed ink droplets is less than or equal to the diameter of the previous printed ink droplets. Compared with the method of increasing the diameter of the printed ink droplets to reduce the width of the blank area, the edge jaggedness of the printed belt can be reduced, and the straightness of the edge of the blank area can be improved, and finally a grid line with a smaller line width variation can be obtained, which effectively improves the quality of the grid line and thus improves the quality of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A method for preparing a gate line in one embodiment of the present invention;

[0036] Figure 2 , Figure 3 , Figure 5 Schematic diagram of a gate line preparation process in one embodiment of the present invention;

[0037] Figure 4 A schematic diagram of the position of the spray hole in one embodiment of the present invention;

[0038] Description of reference numerals:

[0039] 100 - first printing belt; 200 - initial blank area; 201 - blank area; 101 - second printing belt; 102 - third printing belt; 10 - first nozzle hole; 20 - second nozzle hole. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Example

[0045] This embodiment provides a method for preparing a gate line. Figure 1 , including the following steps:

[0046] Step 1: forming a metal seed layer on the surface of the substrate layer; the surface of the metal seed layer has a first direction and a second direction perpendicular to each other;

[0047] Step 2: Perform a first spray printing on the surface of the metal seed layer along the second direction through a plurality of first spray holes with a center spacing of T0 to obtain a plurality of first spray printing bands; the diameter of the ink droplet of the first spray printing is The plurality of first spray holes are arranged parallel to the first direction; the area between adjacent first spray-printed bands on the surface of the metal seed layer is an initial blank area;

[0048] Step 3 performs a second printing along a second direction through a plurality of second nozzles with a center spacing of T0, to obtain a plurality of second printing strips; wherein the plurality of second nozzles are arranged parallel to the first direction and correspond to the plurality of first nozzles in Step 2; the diameter of the ink droplet of the second printing is The second printing belt covers part of the initial blank area formed in step (2); the second printing belt covers part of the first printing belt; the first printing belt and the second printing belt covering it form a composite printing belt; in this step, the area between adjacent composite printing belts on the surface of the metal seed layer is the blank area;

[0049] Step 4 repeats step 3 N times, the nozzle used for each printing is arranged parallel to the first direction, and the diameter of the ink droplets printed is less than or equal to the diameter of the ink droplets of the previous printing; the printing belt formed by each printing covers part of the composite printing belt obtained by the previous printing, and covers part of the blank area obtained by the previous printing. After repeating step Step 3 N times, the area between adjacent composite printing belts on the surface of the metal seed layer is the target blank area; N is an integer greater than or equal to zero;

[0050] Step 5: depositing metal on the target blank area to form a metal layer, thereby obtaining the gate line.

[0051] In previous studies, the inventors increased the diameter of the printed ink droplets to reduce the width of the blank area, thereby narrowing the line width of the grid line. As the diameter of the ink droplets increased, the edge jaggedness of the strip masking layer in the length direction became larger, and the line width of the grid line finally prepared varied greatly. The inventors found that the grid line with varying line width has a direct impact on the quality of the final product; and the minimum line width that can be achieved by increasing the diameter of the ink droplets is larger and more costly; and when preparing the grid line using the above method, the preparation process has higher requirements on the nozzle aperture.

[0052] In the present invention, an initial blank area is first printed on the surface of the metal seed layer; then, the initial blank area is gradually covered by the printing of step (3) and step (4), so that the width of the blank area is gradually reduced, and then metal is deposited to form a grid line; by adopting the technical scheme of the present invention, the width of the blank area between adjacent composite printing belts on the surface of the metal seed layer can be adjusted only by multiple printings; and the width of the blank area can be gradually reduced by the above adjustment, and a grid line with an extremely narrow line width can be prepared according to production requirements; and when faced with requirements for grid lines of different widths, the equipment adjustment cost is low, thereby reducing production costs; and because the width of the blank area is adjusted only by printing, there is no need to remove the printing belt additionally, thereby improving the utilization rate of materials; in summary, the method provided by the present invention can take into account the adjustment of the grid line width size, the prepared grid line width is narrow, the material utilization rate is high during the preparation process, and the production cost is low;

[0053] Furthermore, in the technical solution of the present invention, by determining the center distance of the nozzle holes for printing, multiple printings are used to gradually cover the initial blank area, and the diameter of the printed ink droplets is less than or equal to the diameter of the previous printed ink droplets. Compared with the method of increasing the diameter of the printed ink droplets to reduce the width of the blank area, the edge jaggedness of the printed belt can be reduced, and the straightness of the edge of the blank area can be improved, and finally a grid line with a smaller line width variation can be obtained, which effectively improves the quality of the grid line and thus improves the quality of the final product.

[0054] In this embodiment, the printing material used in printing is selected from hot melt material, wherein the hot melt material has fluidity at a temperature greater than or equal to 50°C and a viscosity of 0.1mPa·S to 20mPa·S; and when the temperature is less than or equal to 25°C, the hot melt material is solid or fluid, and when it is a fluid, the viscosity of the hot melt material is greater than 10000mPa·S.

[0055] In a specific embodiment of the present invention, the printing material used in the printing is selected from one or more of acrylate, rosin ester resin, C11-C22 alkyl acid, polypropylene wax, microcrystalline wax, polyethylene wax or ethylene-vinyl acetate copolymer wax.

[0056] In Step 4 of this embodiment, Step 3 is repeated N times, where N is selected from an integer of 0-3, such as 0, 1, 2, 3; when N is 0, it means that Step 4 is not performed, and the step of forming a metal layer is performed after Step 3 is completed.

[0057] In this embodiment, a metal seed layer is formed on the surface of the substrate layer; the surface of the metal seed layer has a first direction and a second direction that are perpendicular to each other.

[0058] Combine the following Figure 2 , Figure 3 , Figure 5 Provide a detailed description.

[0059] refer to Figure 2 , a first printing is performed on the surface of the metal seed layer along the second direction S2 through a plurality of first nozzles with a center spacing of T0, to obtain a plurality of first printing strips 100; the ink droplet diameter of the first printing is The plurality of first spray holes are arranged parallel to the first direction S1; the area between the adjacent first spray printing bands 100 on the surface of the metal seed layer is the initial blank area 200; the width of the initial blank area 200 is

[0060] In one embodiment, the center distance T0 of the first nozzle holes is 63.5 μm;

[0061] In one embodiment, the diameter of the ink droplet of the first jet printing is 10μm;

[0062] refer to Figure 3 , a second printing is performed along a second direction through a plurality of second nozzles with a center spacing of T0, to obtain a plurality of second printing strips 101; wherein the plurality of second nozzles are arranged parallel to the first direction S1 and correspond to the plurality of first nozzles in Step 2; the ink droplet diameter of the second printing is The second printing band covers part of the initial blank area 200, and the width of the initial blank area covered is T1. and The second printing tape 101 covers part of the first printing tape 100, and the width of the first printing tape 100 covered is The first printing tape 100 and the second printing tape covering it form a composite printing tape. The area between adjacent composite printing tapes on the surface of the metal seed layer is a newly obtained blank area 201. The width of the blank area 201 is

[0063] In a specific embodiment, If T1 is greater than An area not filled with printing material is likely to appear in the middle of the composite printing belt composed of the second printing belt and the first printing belt covering it, which will directly affect the quality of the final product.

[0064] In a specific embodiment, the second printing is performed after the first printing is completed by translating the first nozzle hole along the first direction S1 and then performing printing.

[0065] In the actual production process, when preparing the target width of the grid line, if the blank area of ​​the specific width is obtained by directly printing ink droplets once, the dependence on the nozzle nozzle orifice is high, and the nozzle with a nozzle orifice of a specific size needs to be customized and ink droplets of a specific diameter need to be formed during printing. However, through the above embodiment, multiple printings are used to gradually cover and reduce the width of the blank area to prepare the target width of the grid line. In the preparation process, the nozzle orifice of a single nozzle is the same, and the preparation of the target width of the grid line only needs to be achieved by adjusting the sum of the moving distances during multiple printings to a specific width. The dependence on the nozzle in the entire preparation process is low, and the control accuracy requirement for the diameter of the ink droplets formed by printing is low.

[0066] In another specific embodiment, the second printing is achieved by printing with a second nozzle 20 that is staggered with the first nozzle 10 (the nozzle position is as shown in FIG. Figure 4 shown).

[0067] In the present invention, multiple nozzles can be staggered to achieve staggered settings between corresponding nozzle holes, thereby obtaining a narrower blank area in printing; when preparing target width grid lines, the target width blank area can be obtained by adjusting the number of nozzles and / or adjusting the staggered distance between the nozzles, and finally the target width grid lines are obtained. The preparation process has low dependence on the nozzle hole diameter of the nozzle, and the control accuracy of the ink droplet diameter is also low.

[0068] refer to Figure 5 , the third printing is performed (repeating the second printing process), the nozzle used in the third printing is arranged parallel to the first direction S1, and the diameter of the ink droplet printed is The third printing belt 102 formed by the printing covers part of the composite printing belt obtained by the second printing, and covers part of the blank area 201 formed by the previous printing. The width of the blank area 201 formed by the previous printing is T (1) After the third printing is completed, a new blank area 201 is obtained on the surface of the metal seed layer. The width of the blank area 201 after the third printing is

[0069] In a specific embodiment, the blank area 201 obtained after the third printing is the target blank area, and metal is deposited on the blank area 201 obtained after the third printing to form a metal layer, that is, the gate line to be prepared is obtained.

[0070] For multiple nozzles, adjacent nozzles are staggered, and the apertures of the nozzles can be the same or different. There are no special restrictions on the specific apertures and ink droplet diameters. It only requires that there is a size relationship between the ink droplets ejected from the nozzle holes in adjacent nozzles. By adjusting the sum of the staggered distances between the nozzles before printing, the preparation of target width grid lines can also be achieved. The dependence on the nozzles is low, and the control accuracy of the ink droplet diameter is also low.

[0071] In a specific embodiment, If T (1) Greater than When the third printing tape covers the composite printing tape obtained after the second printing, areas without printed materials are likely to appear, that is, the metal seed layer is likely to be directly exposed between the third printing tape and the composite printing tape obtained after the second printing, which will directly affect the quality of the final product.

[0072] In a specific embodiment, the third printing is not performed after the second printing is completed, that is, the initial blank area 200 is the target blank area, and metal is deposited on the initial blank area 200 formed after the second printing to form a metal layer, that is, the gate line to be prepared is obtained.

[0073] In another specific embodiment, the blank area 201 obtained after the third printing is the target blank area, and metal is deposited on the blank area 201 obtained after the third printing to form a metal layer, that is, the gate line to be prepared is obtained.

[0074] In other embodiments, after the third printing is completed, the second printing process is continued multiple times to gradually narrow the width of the strip-shaped blank area to obtain a target blank area, and finally, metal is deposited on the target blank area to form a metal layer to obtain the gate line to be prepared.

[0075] In one embodiment, the line width of the gate line is 5-20 μm, for example, 5 μm, 10 μm, 15 μm or 20 μm.

[0076] In other embodiments, the width of the required blank area can be adjusted according to actual production needs, and the width can be less than 10 μm.

[0077] In one embodiment, the metal is deposited by electroplating, electroless plating, physical vapor deposition, or chemical vapor deposition.

[0078] In a specific embodiment, the metal seed layer process is chemical vapor deposition or physical vapor deposition; for example, a copper layer is deposited on the substrate surface by physical vapor deposition, and the thickness of the copper layer is 100-1000nm, for example: 100nm, 200nm, 300nm, 500nm or 800nm.

[0079] In one embodiment, the metal seed layer is made of copper; in other embodiments, the metal seed layer may be made of other metal materials, such as aluminum or silver.

[0080] In one embodiment, after the gate lines are formed, the process further includes sequentially removing the printed material on the surface of the metal seed layer and the metal seed layer not covered by the gate lines.

[0081] In a specific embodiment, the printed material on the surface of the metal seed layer can be removed by washing with a corresponding existing solvent.

[0082] In a specific embodiment, the metal seed layer material is copper, and the metal seed layer not covered by the gate line is formed by CuCl 2 The removal is carried out by etching method using alkaline etching solution / sulfuric acid and hydrogen peroxide.

[0083] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the protection scope of the invention.

Claims

1. A method for preparing a gate line, characterized in that: The steps include: (1) forming a metal seed layer on a surface of a substrate layer; the surface of the metal seed layer has a first direction and a second direction perpendicular to each other; (2) performing a first printing on the surface of the metal seed layer along a second direction through a plurality of first nozzles with a center spacing of T0 to obtain a plurality of first printing strips; the diameter of the ink droplets of the first printing is The plurality of first spray holes are arranged parallel to the first direction; the area between adjacent first spray-printed bands on the surface of the metal seed layer is an initial blank area; (3) performing a second printing along a second direction through a plurality of second nozzles with a center spacing of T0 to obtain a plurality of second printing strips; wherein the plurality of second nozzles are arranged parallel to the first direction and correspond to the plurality of first nozzles in step (2); and the diameter of the ink droplets of the second printing is The second printing belt covers part of the initial blank area formed in step (2); the second printing belt covers part of the first printing belt; the first printing belt and the second printing belt covering it form a composite printing belt; in this step, the area between adjacent composite printing belts on the surface of the metal seed layer is the blank area; (4) Repeat step (3) N times, wherein the nozzle used in each printing is arranged parallel to the first direction, and the diameter of the ink droplets printed is less than or equal to the diameter of the ink droplets printed in the previous printing; the printing belt formed by each printing covers part of the composite printing belt obtained by the previous printing, and covers part of the blank area obtained by the previous printing. After repeating step (3) N times, the area between adjacent composite printing belts on the surface of the metal seed layer is the target blank area; N is an integer greater than or equal to zero; (5) Depositing metal on the target blank area to form a metal layer, thereby obtaining the gate line.

2. The preparation method according to claim 1, characterized in that: In step (2), the width of the initial blank area is Preferably, in step (3), the second printing tape covers part of the initial blank area, and the width of the initial blank area covered is T1. and The second printing belt covers part of the first printing belt, and the width of the first printing belt covered is The width of the blank area obtained in step (3) is Preferably, in step (4), when the i-th repetition of step (3) is repeated N times, the printed band formed by the printing covers part of the blank area obtained by the previous printing, and the width of the blank area obtained by the previous printing is T (i) ; i is an integer between 0 and N; after repeating step (3) N times, the width of the target blank area is 3. The preparation method according to claim 1, characterized in that: The substrate layer is a silicon wafer.

4. The preparation method according to claim 1, characterized in that: In step (5), the method of depositing the metal is selected from electroplating, chemical plating, physical vapor deposition or chemical vapor deposition.

5. The preparation method according to claim 4, characterized in that: After the gate lines are formed, the method further includes removing the printed material on the surface of the metal seed layer and the metal seed layer not covered by the gate lines in sequence.

6. The preparation method according to claim 1, characterized in that: The printing material used in the printing is selected from hot melt materials, wherein the hot melt material has fluidity at a temperature greater than or equal to 50°C and a viscosity of 0.1 mPa·S to 20 mPa·S; and when the temperature is less than or equal to 25°C, the hot melt material is solid or fluid, and when it is fluid, the viscosity of the hot melt material is greater than 10000 mPa·S; Preferably, the printing material used in the printing is selected from one or more of acrylate, rosin ester resin, C11-C22 alkyl acid, polypropylene wax, microcrystalline wax, polyethylene wax, and ethylene-vinyl acetate copolymer wax.

7. The preparation method according to claim 1, characterized in that: The ink droplet diameter in step (3) is the same as the ink droplet diameter in step (2); the second nozzle in step (3) is the nozzle obtained by translating the first nozzle in step (2) along the first direction; and / or, The ink droplet diameter in step (4) is the same as the ink droplet diameter in step (2); the nozzle in step (4) is the nozzle obtained by translating the first nozzle in step (2) along the first direction.

8. The preparation method according to claim 1, characterized in that: The second spray hole in step (3) is a spray hole that is offset from the first spray hole in step (2); and / or, The spray hole in step (4) is a spray hole that is offset from the first spray hole in step (2).

9. The preparation method according to claim 1, characterized in that: In step (3), and / or, In step (4), T (i) Less than or equal to 0.85 times the diameter of the ink droplet printed this time.

10. A gate line, characterized in that: The preparation method is described in any one of claims 1 to 8.

Images