Full-aperture stencil and printing device

Abstract

A full-aperture stencil and a printing device. The full-aperture stencil comprises a stencil main body (110), the stencil main body (110) is formed with a full-aperture pattern for single-pass printing of fine-fingers and busbars or connecting lines connected to the fine fingers, wherein the full-aperture pattern comprises a plurality of main lines (1) extending in a first direction and a plurality of connecting portions disposed on the main lines (1) in a second direction, and the main lines (1) are provided as continuous openings configured for printing and forming the fine fingers. The connecting portions are configured for simultaneously printing and forming the connecting lines during printing, so as to bridge the fine fingers adjacent in the second direction. The stencil main body (110) comprises a first metal layer (111) and a second metal layer (112). The first metal layer (111) forms a contour of the full-aperture pattern. The second metal layer (112) is stacked on the first metal layer (111) and is provided with a paste-permeable pattern (3) corresponding to the full-aperture pattern, and the paste-permeable pattern (3) is provided with discontinuous openings at least in an area corresponding to the connecting portions.

Description

Fully open steel plate and printing equipment

[0001] This application claims priority to Chinese Patent Application No. 202510460414.0, filed with the Chinese Patent Office on April 14, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of printing technology for heterojunction solar cells (HJT), and for example to a fully open stencil and printing equipment. Background Technology

[0003] In solar cell printing technology, traditional screen printing plates are limited by their mesh structure, making it difficult to meet the requirements for extremely fine line widths. As a result, fully open steel plates have emerged to overcome the bottlenecks in line width and flatness.

[0004] However, traditional fully open steel plates typically require multi-stage printing when printing solar cells, and cannot be completed in a single pass. Specifically, two sets of steel plates are needed for printing: one set is used to print the fine grids, and the other set is used to print the main grids or the connecting lines of the corresponding solder strips.

[0005] Because two sets of steel plates need to be mechanically aligned and positioned during step-by-step overprinting, and because the dimensional accuracy deviations during plate replacement can easily lead to alignment errors between the fine grid and the main grid or connecting lines. In addition, the silver paste will be repeatedly applied to the overlapping area between the fine grid and the main grid or connecting lines, and the position of the overprinting deviation needs to be compensated for, resulting in silver paste waste. Summary of the Invention

[0006] This application provides a fully open stencil and printing equipment to avoid problems such as alignment errors and silver paste waste, and has high production efficiency.

[0007] This application provides a fully open steel plate, the fully open steel plate comprising:

[0008] A steel plate body, on which a fully open pattern is formed for single-printing of fine grids and main grids or connecting lines connected to the fine grids, the fully open pattern including:

[0009] A plurality of main lines extending along a first direction, the main lines being continuously open and configured to be printed to form a fine grid; and,

[0010] Multiple connecting portions are provided on the main line along the second direction, and the connecting portions are configured to be printed synchronously to form the main grid or the connecting line during printing, so as to bridge the adjacent fine grids in the second direction;

[0011] The main body of the steel plate includes:

[0012] A first metal layer, the first metal layer forming the outline of the fully open pattern; and,

[0013] A second metal layer is stacked on top of the first metal layer and has an ink-transmitting pattern corresponding to the fully open pattern, wherein the ink-transmitting pattern is discontinuously open at least in the region corresponding to the connection portion.

[0014] In some embodiments, the connecting portion includes:

[0015] The first connecting portion extends along the first direction and is configured to connect two adjacent main lines in the first direction, and...

[0016] The second connecting portion extends along the second direction and is configured to bridge the main line adjacent in the second direction.

[0017] In some embodiments, the opening width of the first connecting portion gradually increases from both ends toward the middle.

[0018] In some embodiments, the second metal layer is further provided with a plurality of reinforcing grids, each of which corresponds to a plurality of the first connecting portions, and each of the reinforcing grids includes a plurality of slurry passage holes.

[0019] In some embodiments, the reinforcing mesh is formed by perforation in the second metal layer to form a plurality of the slurry passage holes, and a blocking portion is formed between adjacent slurry passage holes.

[0020] In some embodiments, the first metal layer is further provided with a plurality of guide grooves, and the plurality of guide grooves are divided into multiple columns. Each column of the second connecting portion has a column of guide grooves arranged on both sides, and the ends of the plurality of guide grooves in the same column that are close to the second connecting portion are all connected to the second connecting portion.

[0021] In some embodiments, each of the guide grooves is inclined so that it forms an angle with the scraping direction of the doctor blade or the ink return blade.

[0022] In some embodiments, the multiple guide grooves in the same column have the same tilt direction and angle, and the guide grooves in two columns distributed on both sides of the second connecting portion in the same column have opposite tilt directions.

[0023] In some embodiments, both the first metal layer and the second metal layer are made of a nickel-cobalt alloy.

[0024] This application also provides a printing apparatus, including a frame, an ink supply mechanism, a pad printing mechanism, and the aforementioned fully open steel plate. The ink supply mechanism, the pad printing mechanism, and the fully open steel plate are all disposed on the frame. The pad printing mechanism is configured to print the silver paste supplied by the ink supply mechanism onto the substrate in a single pass through the fully open steel plate to form a fine grid, and a main grid or connecting line connected to the fine grid. Attached Figure Description

[0025] Figure 1 is a structural schematic diagram of the fully open steel plate provided in this application;

[0026] Figure 2 is a partial structural schematic diagram of the fully open steel plate provided in this application;

[0027] Figure 3 is a schematic diagram of the structure of the first connecting part and the reinforcing mesh provided in this application;

[0028] Figure 4 is a structural schematic diagram of the second connecting part and the ink-permeable pattern provided in this application;

[0029] Figure 5 is a schematic diagram of the structure of a printing device provided in this application.

[0030] In the picture:

[0031] 1. Main line; 2. Second connecting part; 3. Ink-permeable pattern; 4. First connecting part; 5. Reinforcing grid; 6. Slurry passage hole; 7. Guide groove; 8. Blocking part;

[0032] 10. Printing equipment; 100. Fully open steel plate; 110. Steel plate body; 111. First metal layer; 112. Second metal layer; 200. Frame; 300. Ink supply mechanism; 310. Silver paste; 400. Pad printing mechanism; 500. Battery cell. Detailed Implementation

[0033] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0034] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0035] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0036] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0037] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0038] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0039] Please refer to Figures 1 to 5. This embodiment provides a fully open stencil 100, which includes a stencil body 110. The stencil body 110 has a fully open pattern formed on it for single-printing of fine grids and connecting lines. The fully open pattern includes a plurality of main lines 1 extending along a first direction and a plurality of connecting portions disposed on the main lines 1 along a second direction. The main lines 1 are continuously open and configured to form fine grids during printing. The connecting portions are configured to simultaneously form connecting lines during printing, thereby bridging adjacent fine grids in the second direction.

[0040] In this embodiment, the steel plate body 110 may include a first metal layer 111 and a second metal layer 112. The first metal layer 111 forms the outline of a fully open pattern. The second metal layer 112 is stacked on top of the first metal layer 111 and has an ink-transmitting pattern 3 corresponding to the fully open pattern, wherein the ink-transmitting pattern 3 is discontinuously open at least in the region corresponding to the connection portion.

[0041] It should be noted that this embodiment is illustrated using a printed gridless solar cell as an example. Therefore, the connecting part is set to correspond to the connecting line on the solar cell. In other embodiments, the connecting part can also be set to correspond to the grid of the solar cell for printing the grid.

[0042] When the squeegee scrapes across the surface of the second metal layer 112, the silver paste 310 penetrates through the ink-penetrating pattern 3 onto the first metal layer 111. Constrained by the outline of the fully open pattern, the silver paste 310 penetrates along a linear trajectory onto the substrate (as shown in Figure 5, the battery cell 500), forming fine grids and connecting lines on the substrate. The connecting lines then connect adjacent fine grids in the first direction into a complete fine grid. This configuration allows for the printing of fine grids, as well as main grids or connecting lines connected to them, in a single pass. Compared to the step-by-step overprinting method used in traditional fully open stencil printing, this avoids alignment errors and silver paste 310 waste, while also resulting in higher production efficiency.

[0043] In some embodiments, the connecting portion includes a first connecting portion 4 and a second connecting portion 2. The first connecting portion 4 extends along a first direction and is configured to connect two adjacent main lines 1 in the first direction. The second connecting portion 2 extends along a second direction and is configured to bridge adjacent main lines 1 in the second direction. In this embodiment, the first direction and the second direction are perpendicular. The first connecting portion 4 and the second connecting portion 2 are respectively configured to correspond to the weld beads in the first direction and the second direction. This configuration allows for the single printing of two intersecting connecting lines, avoiding the problem of paste overflow at the intersection of the two connecting lines caused by step-by-step overprinting, thereby helping to reduce the waste of silver paste 310.

[0044] For example, the opening width of the first connecting portion 4 gradually increases from both ends to the middle. With this configuration, the first connecting portion 4 forms a gradient structure that is narrow at both ends and wide in the middle. During printing, the silver paste 310 first fills the middle of the first connecting portion 4, and then the silver paste 310 gradually fills the two ends, thereby preventing the silver paste from overflowing at both ends of the first connecting portion 4.

[0045] Generally, the area where the first connecting portion 4 connects the two main lines 1 is a stress concentration area, which is prone to breakage due to printing pressure deformation. Therefore, in this embodiment, a plurality of reinforcing meshes 5 are also provided on the second metal layer 112, with each reinforcing mesh 5 corresponding to one of the first connecting portions 4. Each reinforcing mesh 5 includes a plurality of ink passage holes 6. The reinforcing meshes 5 form a support structure above the first connecting portions 4, thereby improving the structural strength of the area on the first metal layer 111 where the first connecting portion 4 connects the two main lines 1. It is worth noting that the pattern formed by the plurality of ink passage holes 6 is also part of the ink-permeable pattern 3 mentioned earlier.

[0046] In this embodiment, the reinforcing mesh 5 is perforated on the second metal layer 112 to form multiple ink passage holes 6, and a blocking portion 8 is formed between adjacent ink passage holes 6. It is understood that the ink passage holes 6 can guide the silver paste 310 to penetrate downwards, and the adjacent blocking portions 8 can support the lower first metal layer 111, preventing collapse when the doctor blade and ink return blade apply pressure. It should be noted that the shape and size of the ink passage holes 6 are selected according to the actual application scenario. For example, the shape of the ink passage holes 6 may include hexagons, trapezoids, rectangles, arcs, etc.

[0047] During printing, the doctor blade and ink return blade typically reciprocate to achieve uniform distribution of the silver paste. To ensure that the silver paste 310 can better fill the second connecting portion 2, the first metal layer 111 is also provided with multiple guide grooves 7, which are arranged in multiple rows. Each row of guide grooves 7 is arranged on both sides of the second connecting portion 2, and the ends of the multiple guide grooves 7 in the same row that are closest to the second connecting portion 2 are connected to the second connecting portion 2. With this arrangement, the doctor blade and ink return blade draw the silver paste 310 along the groove walls of the guide grooves 7 towards the second connecting portion 2, thereby avoiding the problem of insufficient material in the second connecting portion 2.

[0048] In some embodiments, each guide groove 7 is inclined, forming an angle with the scraping direction of the doctor blade or the return blade. It is understood that the inclined guide groove 7 creates a pressure difference within the silver paste 310 during the scraping process of the doctor blade and the return blade. As the doctor blade and the return blade move, the silver paste 310 experiences higher pressure at the front end and lower pressure at the rear end under the influence of the inclined guide groove 7. This promotes smoother flow of the silver paste 310 into the second connecting portion 2, increasing the filling amount and speed of the silver paste 310 within the second connecting portion 2, and reducing connection problems caused by insufficient filling of the silver paste 310. It is also understandable that the inclined guide groove 7 is set at an angle to the scraping direction of the doctor blade or ink return blade, which allows the silver paste 310 to be more evenly dispersed in the guide groove 7 before entering the second connecting part 2. This allows the silver paste 310 to be more evenly distributed in the second connecting part 2 when it flows in, avoiding local accumulation or gaps in the silver paste 310, and improving the uniformity and consistency of the main grid or connecting line.

[0049] In some embodiments, the multiple guide grooves 7 in the same column have the same tilt direction and angle, while the guide grooves 7 in two columns distributed on both sides of the second connecting portion 2 in the same column have opposite tilt directions. For example, when the doctor blade and the ink return blade move to the right, the guide grooves 7 on the left side tilt to the right, forcing the silver paste 310 to fill the second connecting portion 2 on the right; when the doctor blade and the ink return blade move to the left, the guide grooves 7 on the right side tilt to the left, guiding the silver paste 310 to the second connecting portion 2 on the left. The opposite tilt of the guide grooves 7 on both sides enables forward printing and reverse ink return, avoiding filling dead corners.

[0050] To improve the service life of the fully open steel plate 100, both the first metal layer 111 and the second metal layer 112 are made of nickel-cobalt alloy. Nickel-cobalt alloy has both high hardness and ductility, and can withstand high-frequency mechanical stress (such as the reciprocating friction between the doctor blade and the ink return blade). The first metal layer 111 is not easily deformed, making it more suitable for battery cell printing applications.

[0051] Referring to Figure 5, this embodiment also provides a printing apparatus 10, which includes a frame 200, an ink supply mechanism 300, a pad printing mechanism 400, and the aforementioned fully open steel plate 100. The ink supply mechanism 300, the pad printing mechanism 400, and the fully open steel plate 100 are all mounted on the frame 200. The pad printing mechanism 400 is configured to print the silver paste 310 supplied by the ink supply mechanism 300 onto the substrate (the battery cell 500 shown in Figure 5) in a single pass through the fully open steel plate 100 to form fine grids and main grids or connecting lines connected to the fine grids. It is understood that the printing apparatus 10 including the aforementioned fully open steel plate 100 has high production efficiency.

Claims

1. A fully open steel plate, comprising: A steel plate body (110) has a fully open pattern formed on it for single-printing of fine grids and main grids or connecting lines connected to the fine grids. The fully open pattern includes: A plurality of main lines (1) extending along a first direction, the main lines (1) being continuously open and configured to be printed to form a fine grid; and, Multiple connecting portions are provided on the main line (1) along the second direction, the connecting portions being configured to be printed synchronously to form the main grid or the connecting line during printing, so as to bridge the adjacent fine grids in the second direction; The main body of the steel plate (110) includes: A first metal layer (111) forms the outline of the fully open pattern; and, A second metal layer (112) is stacked on top of the first metal layer (111) and has an ink-transmitting pattern (3) corresponding to the fully open pattern, wherein the ink-transmitting pattern (3) is provided with discontinuous openings at least in the region corresponding to the connection portion.

2. The all-open steel plate according to claim 1, wherein The connecting part includes: The first connecting portion (4) extends along the first direction and is configured to connect two adjacent main lines (1) in the first direction, and, The second connecting portion (2) extends along the second direction and is configured to bridge the main line (1) adjacent in the second direction.

3. The all-open steel plate according to claim 2, wherein, The opening width of the first connecting part (4) gradually increases from both ends to the middle.

4. The all-open steel plate according to claim 3, wherein, The second metal layer (112) is also provided with a plurality of reinforcing grids (5), and the plurality of reinforcing grids (5) are provided in a one-to-one correspondence with the plurality of first connecting portions (4). Each reinforcing grid (5) includes a plurality of slurry passage holes (6).

5. The all-open steel plate according to claim 4, wherein, The reinforcing mesh (5) is hollowed out on the second metal layer (112) to form a plurality of the pulp passage holes (6), and a blocking part (8) is formed between adjacent pulp passage holes (6).

6. The all-open steel plate according to claim 2, wherein, The first metal layer (111) is also provided with a plurality of guide grooves (7), and the plurality of guide grooves (7) are divided into multiple columns. Each column of the second connecting part (2) has a column of guide grooves (7) arranged on both sides. The ends of the plurality of guide grooves (7) in the same column that are close to the second connecting part (2) are all connected to the second connecting part (2).

7. The all-open steel plate according to claim 6, wherein, Each of the guide grooves (7) is inclined so that it is set at an angle to the scraping direction of the doctor blade or the ink return blade.

8. The all-open steel plate according to claim 7, wherein, The multiple guide grooves (7) in the same column have the same tilt direction and angle, and the guide grooves (7) in two columns distributed on both sides of the second connecting part (2) in the same column have opposite tilt directions.

9. The all-open steel plate according to claim 1, wherein, Both the first metal layer (111) and the second metal layer (112) are made of nickel-cobalt alloy.

10. A printing device comprising a frame (200), an ink supply mechanism (300), a pad printing mechanism (400) and the full open steel stencil (100) as claimed in any one of claims 1-9, the ink supply mechanism (300), the pad printing mechanism (400) and the full open steel stencil (100) are all arranged on the frame (200), the pad printing mechanism (400) is arranged to print the silver paste (310) supplied by the ink supply mechanism (300) through the full open steel stencil (100) onto a printing substrate in a single printing to form a fine grid and a main grid or a connecting line connected with the fine grid.

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