Solar cell printing screen and solar cell

Abstract

The utility model discloses a solar cell printing screen and solar cell. Solar cell printing screen includes screen frame and installs the screen edition body of screen frame, the screen edition body is provided with printing area, a plurality of printing grid lines are arranged in the printing area, the printing grid line is set up through the screen edition body, wherein, at least one side interval of printing area is provided with the flow adjustment area, the interval average distance of flow adjustment area and printing area is greater than 100um, a plurality of micro blind holes are arranged in the flow adjustment area. The flow adjustment area can effectively adjust the flow field of slurry in the printing process under the premise of guaranteeing the mechanical strength of the printing screen, thereby improving the uniformity and quality of printing, and the conductivity and conversion efficiency of the solar cell are improved.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a solar cell printing screen and a solar cell. Background Technology

[0002] In the manufacturing process of solar cells, screen printing technology is typically used to prepare conductive electrodes on the light-receiving surface of the cell. These electrodes usually appear as multiple thin grid lines. The printing screen is a key tool in this process, and its structure directly determines the printing quality of the electrodes, such as width, thickness, and uniformity, which in turn directly determines the current collection efficiency and final conversion efficiency of the solar cell.

[0003] Printing screens typically consist of a printing area for forming grid lines. However, during the printing process, the ink flows across the printing screen under the pressure of a squeegee. Existing printing screens are prone to causing uneven ink flow, which can lead to problems such as uneven printing or broken lines. Utility Model Content

[0004] Therefore, it is necessary to provide a new solar cell printing screen and solar cell to solve the above-mentioned technical problems.

[0005] One technical solution of this utility model is: a solar cell printing screen, which includes a screen frame and a screen body installed on the screen frame. The screen body is provided with a printing area, and a plurality of printing grid lines are arranged in the printing area. The printing grid lines are arranged through the screen body. At least one side of the printing area is provided with a current adjustment area at intervals. The average distance between the current adjustment area and the printing area is greater than 100μm. A plurality of micro blind holes are arranged in the current adjustment area.

[0006] In one embodiment, the average distance between the flow adjustment zone and the printing zone is less than 5 mm, and the width of the flow adjustment zone ranges from 3 mm to 100 mm.

[0007] In one embodiment, the micro-blind holes are circular, triangular, polygonal, elliptical, or irregular in shape, and a plurality of the micro-blind holes are regularly or randomly distributed.

[0008] In one embodiment, the average aperture of the micro-blind holes ranges from 20μm to 200μm, and the spacing between adjacent micro-blind holes ranges from 20μm to 300μm.

[0009] In one embodiment, the printed grid lines extend along the X direction, and a plurality of the printed grid lines are arranged at intervals along the Y direction perpendicular to the X direction. The flow adjustment area is provided on the left and right sides of the printing area along the X direction.

[0010] In one embodiment, a stress-relief zone is provided on each of the upper and lower sides of the printing area along the Y direction. The stress-relief zone is spaced apart from the printing area, and a plurality of stress-relief grooves extending along the X direction are arranged in the stress-relief zone.

[0011] In one embodiment, the edge of the mesh body is provided with an elastic zone, and a number of perforations are regularly or randomly distributed within the elastic zone.

[0012] In one embodiment, the elastic area is provided to enclose a ring around the perimeter of the mesh body, and the perforation is a circular hole.

[0013] In one embodiment, the printed grid line includes an opening penetrating the screen print body, and at least one segment of the printed grid line is configured as a control segment, the control segment including a flow control portion that protrudes and / or retracts into the opening and / or out of the opening.

[0014] This utility model also discloses a solar cell, which includes a silicon wafer and conductive electrodes disposed on the silicon wafer, wherein the conductive electrodes are formed by printing using a solar cell printing screen as described above.

[0015] The beneficial effects of this invention are: the flow adjustment zone can effectively adjust the flow field of the paste during the printing process while ensuring the mechanical strength of the printing screen, thereby improving the uniformity and quality of printing, and improving the conductivity and conversion efficiency of the solar cell. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the solar cell printing screen of this utility model;

[0017] Figure 2 for Figure 1 A magnified view of a portion of the center circle A1;

[0018] Figure 3 for Figure 1 A magnified view of a portion of the center circle A2;

[0019] Figure 4 for Figure 1 A magnified view of the layers in the middle circle A3;

[0020] Figure 5 for Figure 3 A magnified view of a portion of the center circle B1;

[0021] Figure 6 for Figure 3 A magnified view of a portion of the center circle B2;

[0022] Figure 7 for Figure 3 A partial cross-sectional schematic diagram;

[0023] Figure 8 for Figure 3 Another partial cross-sectional schematic diagram;

[0024] Figure 9 for Figure 4 A magnified view of a portion of the center circle C;

[0025] Figure 10 This is a magnified three-dimensional schematic diagram of a portion of the printing grid lines of the solar cell printing screen of this utility model.

[0026] Figure 11 for Figure 10 A magnified view of a portion of the center circle D1;

[0027] Figure 12 for Figure 12 A magnified view of a portion of the center circle D2;

[0028] Figure 13 for Figure 12 A related diagram from another angle;

[0029] Figure 14 This is another partial cross-sectional schematic diagram of the solar cell printing screen of this utility model;

[0030] Figure 15 This is another partial cross-sectional schematic diagram of the solar cell printing screen of this utility model;

[0031] Figure 16 This is another partially enlarged schematic diagram of the solar cell printing screen of this utility model;

[0032] Figure 17 for Figure 16 A magnified view of a portion of the center circle E;

[0033] Figure 18 for Figure 17 Another enlarged schematic diagram;

[0034] Figure 19 for Figure 17 Another enlarged schematic diagram. Detailed Implementation

[0035] To facilitate understanding of this utility model, a more comprehensive description will be given below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described below. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0036] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] This invention relates to a solar cell printing screen, comprising a screen frame and a screen body mounted on the screen frame. The screen body has a printing area with a plurality of printing grid lines arranged within the printing area, the printing grid lines penetrating the screen body. At least one side of the printing area is provided with a flow-regulating zone, the average distance between the flow-regulating zone and the printing area being greater than 100 μm, and the flow-regulating zone contains a plurality of micro-blind holes. The flow-regulating zone can effectively regulate the flow field of the printing paste during the printing process while ensuring the mechanical strength of the printing screen, thereby improving the uniformity and quality of the printing.

[0039] Ensuring mechanical strength: The flow adjustment zone replaces the traditional solid area, forming a regular and dense array of tiny blind holes on the screen. This structure removes excess material to facilitate ink flow while retaining sufficient support, effectively ensuring the overall structural stability and mechanical strength of the screen and preventing excessive deformation under printing tension.

[0040] Specifically, during the printing process, a doctor blade propels the ink across the screen printing plate. A flow control zone located on the side of the printing area, with micro-blind holes, can "capture" and "release" a small amount of ink, acting as a "ink buffer" or "micro-flow resistance." This balances the ink pressure at the edges and center of the printing area, making the ink flow more uniform and stable, preventing ink accumulation at the end of the printing area or shortage at the beginning. By optimizing the ink flow field, the printing consistency of the grid lines can be ensured, resulting in more uniform width and thickness of the conductive electrodes. This effectively reduces defects such as broken lines, incomplete printing, and ink bleeding, thereby improving the conductivity and conversion efficiency of the solar cell.

[0041] In one embodiment, the average distance between the flow adjustment zone and the printing zone is less than 5 mm, and the width of the flow adjustment zone ranges from 3 mm to 20 mm. The micro-blind holes are circular, triangular, polygonal, elliptical, or irregularly shaped, and are regularly or randomly distributed. The average diameter of the micro-blind holes ranges from 20 μm to 200 μm, and the spacing between adjacent micro-blind holes ranges from 30 μm to 300 μm. This effectively regulates the distribution and pressure of the paste, resulting in a more uniform and consistent amount of paste flowing to each printing grid line, thereby printing conductive electrodes with high uniformity in width and thickness.

[0042] In one embodiment, the printing grid lines extend along the X direction, and a plurality of printing grid lines are arranged at intervals along the Y direction perpendicular to the X direction. A flow adjustment zone is provided on each of the left and right sides of the printing area along the X direction. This balances the paste pressure on the left and right sides of the printing area, ensuring uniform paste distribution in the Y direction.

[0043] In one embodiment, a stress-relief zone is provided on both the upper and lower sides of the printing area along the Y direction, with the stress-relief zone spaced apart from the printing area. Several stress-relief grooves extending along the X direction are arranged within the stress-relief zone. The stress-relief groove structure of the stress-relief zone can effectively absorb and release the internal stress generated by the squeegee pressure during printing, reduce local deformation of the screen print body, protect the printed grid lines from distortion, and improve printing quality.

[0044] In one implementation, an elastic zone is provided at the edge of the mesh screen body, and several perforations are regularly or randomly distributed within the elastic zone. For example, the elastic zone is set around the four edges of the mesh screen body, and the perforations are circular holes. The arrangement of circular perforations in the elastic zone forms a flexible buffer zone, which can evenly distribute the tension force of the mesh screen body on the frame and buffer the impact from the outside, significantly reducing stress concentration at the edge of the mesh screen body and preventing cracking and permanent deformation.

[0045] The flow adjustment zone, stress relief zone, and elastic zone together constitute a complete mechanical and fluid dynamics optimization system. This system not only ensures high printing quality (uniform grid lines, no broken lines, no ink bleeding), but also enhances the mechanical durability and fatigue resistance of the printing screen, extends the service life of the printing screen, and reduces the frequency of replacement and maintenance costs in production.

[0046] In one embodiment, the printing grid line includes an opening penetrating the screen printing body, and at least one segment of the printing grid line is configured as a control segment. The control segment includes a flow control portion protruding and / or recessed into and / or outside the opening. The flow control portion is used to control the flow path of the ink during the squeegee printing process, disperse the flow resistance of the ink, and avoid sudden changes in ink amount caused by changes in aperture, thereby increasing ink amount, improving printing uniformity, and ensuring the reliability of the printing screen. Furthermore, by obtaining electrodes with a high aspect ratio, uniformity, and continuity, the fill factor and photoelectric conversion efficiency are improved, thereby improving the reliability and lifespan of the solar cell.

[0047] The principle is analyzed as follows: When the openings of the printing grid are continuous, the pressure applied by the squeegee during printing can form a uniform and continuous ink roller. The ink receives continuous and uniform shearing, resulting in good fluidity and efficient extrusion of the ink through the openings. When there are changes in the aperture of the printing grid or connecting bridges are installed, the continuity of the opening is interrupted, the flow path is disturbed, the shearing effect is uneven or weakened, leading to poor fluidity, resulting in the dispersion and loss of local pressure, and thus reducing the amount of ink applied. By setting a control section on the printing grid to cope with the changes in the openings, correspondingly, protruding and recessed flow control parts are set inside and outside the openings to control the flow of ink, disperse the flow resistance of ink, avoid sudden changes in the uniformity of ink application, and suppress printing defects such as tailing and insufficient ink application. The flow control parts actively intervene, guide, and redistribute the ink flowing through this section, eliminate eddies, stabilize the pressure distribution, eliminate printing defects at the source, improve ink application, and ensure the uniformity of the aspect ratio and the overall continuity of the conductive electrodes.

[0048] In one embodiment, the opening includes a sidewall located within the opening, and the flow control part includes a recessed notch and / or protruding teeth from the sidewall. The notch communicates with the opening, and the teeth protrude into the cavity of the opening. During squeegee printing, the notch or teeth can redistribute the ink flowing through that section, improving ink application performance. Furthermore, the sidewall includes a first sidewall and a second sidewall disposed opposite to each other, with the protruding teeth of the first sidewall and the protruding teeth of the second sidewall symmetrically, asymmetrically, or misaligned.

[0049] In one embodiment, the printed grid lines further include a plurality of spaced connecting bridges disposed within the opening, and the sidewalls include a third sidewall of the connecting bridges located within the control section, with a control gap formed between the teeth of the first, second, or third sidewalls. The control gaps actively adjust the aperture of the opening, thereby controlling the flow of the slurry.

[0050] In one embodiment, the printing grid lines are arranged longitudinally, and the teeth include a flow-controlling surface located within the cavity of the opening, the flow-controlling surface being perpendicular or inclined to the longitudinal direction. Symmetrically or staggered flow-controlling surfaces are positioned within the cavity of the opening to actively regulate the ink flow and improve printing quality.

[0051] In one embodiment, the printing grid is longitudinally arranged, and within a control section, the opening width varies along a direction perpendicular to the longitudinal direction. The printing grid includes a regular section and a widened section whose opening width is greater than that of the regular section. The control section is located between the regular and widened sections. The printing grid also includes a connecting bridge located between the widened and control sections and disposed within the opening. The widened section is located between two regular sections, and a control section is provided at one or both ends of the widened section. The change in opening diameter between the regular and widened sections can cause turbulence in the slurry flow, generating eddies or localized low-pressure areas. Therefore, a flow control section is provided between the regular and widened sections. The flow control unit within the control section actively adjusts the opening geometry to optimize the dynamic behavior of the slurry fluid, thereby suppressing printing defects, eliminating abrupt changes, and improving printing quality.

[0052] In one embodiment, the widened section and the control section are provided with an integral settling groove on the upper and / or lower side of the opening to form an ink-draining ladder. The ink-draining ladder includes two opposing longitudinal ribs, a transverse rib connecting the two longitudinal ribs, and a through hole located between adjacent transverse ribs. The ink-draining ladder improves ink-draining performance.

[0053] In one embodiment, the printing grid includes a printing groove and an opening extending through the bottom of the printing groove. The width of the printing groove is greater than the width of the opening, and a plurality of comb-like teeth are arranged on both sides of the opening within the printing groove. When the ink flows within the printing groove, the comb-like teeth regulate the ink flow, thereby improving ink application performance.

[0054] In one embodiment, the screen printing body includes a printing surface and a substrate surface arranged opposite each other. A printing groove is recessed from the printing surface, and an opening extends from the bottom of the printing groove to the substrate surface. Several microstructures are distributed on the printing surface of adjacent printing grid lines. The microstructures are raised and / or recessed, and are regularly or randomly distributed. The microstructures are polygonal, circular, elliptical, or irregularly shaped. The microstructures are not penetrating; their arrangement facilitates control of the ink flow by the doctor blade during printing, improving printing stability and ink distribution.

[0055] In one embodiment, the opening includes side edges on both sides, and the flow control section includes blocking strips that are raised and / or recessed from the side edges. The printing grid lines extend along the longitudinal direction, and the blocking strips are arranged perpendicular to or inclined to the longitudinal direction. A plurality of blocking strips are distributed on both side edges and arranged symmetrically or asymmetrically. The blocking strips regulate the ink flow, improving ink distribution performance.

[0056] In one embodiment, the printing grid line further includes a connecting bridge located within the opening, and the control section is provided with an integral settling groove on the upper and / or lower side of the opening to form an ink-draining ladder. The ink-draining ladder includes two opposing longitudinal ribs, a transverse rib connecting the two longitudinal ribs, and a through hole located between adjacent transverse ribs to improve ink-draining performance.

[0057] In one embodiment, the blocking strips are raised, with their free ends not reaching, just reaching, or protruding into the settling tank. The blocking strips are distributed on both sides of the transverse ribs and are aligned with the ribs. The slurry flow is actively adjusted according to the configuration.

[0058] In one embodiment, the screen printing body includes a printing surface and a substrate surface disposed opposite to each other, a printing groove is recessed from the printing surface, an opening extends from the bottom of the printing groove to the substrate surface, and a blocking strip is disposed at the bottom of the printing groove, extending from the side wall of the printing groove toward the opening.

[0059] A solar cell includes a silicon wafer and conductive electrodes disposed on the silicon wafer, wherein the conductive electrodes are formed by screen printing as described above using a solar cell printing stencil. The conductive electrodes have more uniform width and thickness, improving the conductivity and conversion efficiency of the solar cell.

[0060] The following description, with reference to the illustrations, illustrates the solar cell printing screen of this invention.

[0061] Please refer to Figures 1 to 13 This utility model discloses a solar cell printing screen 100, which includes a screen frame 101 and a screen body 1 mounted on the screen frame 101. The screen body 1 is provided with a printing area 13, and a plurality of printing grid lines 2 are arranged in the printing area 13, penetrating the screen body 1. The printing grid lines 2 include openings 21 penetrating the screen body 1, and at least one segment of the printing grid line 2 is configured as a control segment W1. The control segment W1 includes flow control parts 3 that are protruding and recessed into the openings 21. The flow control parts 3 are used to control the flow path of the ink during the squeegee printing process, disperse the flow resistance of the ink, avoid sudden changes in ink amount caused by changes in aperture, thereby increasing the ink amount, improving printing uniformity, and ensuring the reliability of the printing screen 100.

[0062] The printing grid lines 2 are arranged longitudinally, with the extension direction defined as X. Several printing grid lines 2 are spaced apart along the Y direction, perpendicular to the X direction. The printing grid lines 2 of the printing screen 100 are knot-free, improving the aperture ratio, saving ink, and enhancing printing efficiency and quality. The printing grid lines 2 along the X direction include a regular segment W2, a widened segment W3 whose aperture width is greater than that of the regular segment W2, and a control segment W1 located between the regular segment W2 and the widened segment W3. The printing grid lines 2 also include a connecting bridge 22 located between the widened segment W3 and the control segment W1 and disposed within the aperture 21. The widened segment W3 is located between two regular segments W2. In this embodiment, the widened segment W3 has a gradually widened segment W31 and a uniformly widened segment W32. The aperture 21 of the gradually widened segment W31 changes from gradually increasing to uniformly distributed to gradually decreasing. Control segments W1 are disposed at both ends of the gradually widened segment W31. The apertures 21 within the uniformly widened section W32 are uniformly sized, and a control section W1 is provided at one end of the section W1. The apertures 21 in the control section W1 are gradually sized, gradient-shaped, or stepped. The aperture variation of the apertures 21 is further increased by the presence of protruding and / or recessed flow control parts 3 within the control section W1.

[0063] The printing grid 2 also includes a printing groove 23 and an opening 21 extending through the bottom of the printing groove 23. The width of the printing groove 23 is greater than the width of the opening 21. The screen printing body 1 includes a printing surface 11 and a bearing surface 12 disposed opposite to each other. The printing groove 23 is recessed from the printing surface 11, and the opening 21 extends through the bottom of the printing groove 23 to the bearing surface 12.

[0064] The opening 21 includes a sidewall located within the opening, and the flow control part 3 includes a recess 31 recessed from the sidewall and teeth 32 protruding from the sidewall. The recess 31 communicates with the opening 21, and the teeth 32 protrude into the cavity of the opening 21. The sidewall includes a first sidewall 211 and a second sidewall 212 arranged opposite to each other, with the protruding teeth 32 of the first sidewall 211 and the protruding teeth 32 of the second sidewall 212 symmetrically arranged. In other embodiments, they may also be arranged asymmetrically or staggered. The protruding teeth 32 of the first sidewall 211 and the protruding teeth 32 of the second sidewall 212 are arranged opposite to each other, and a control gap is formed between the teeth 32.

[0065] The two ends of the gradually widened section W31 are respectively designated as the first control section W11 and the second control section W12. Within the first control section W11, the sidewall also includes a third sidewall 213 located in the connecting bridge 22. The teeth 32 protruding into the cavity of the opening 21 of the third sidewall 213 are arranged opposite to the teeth 32 protruding from the first sidewall 211 and the second sidewall 212, and a control gap is formed between the teeth 32.

[0066] The recess 31, after being recessed, increases the diameter of the opening 22 at this location, thus increasing the cavity volume. The tooth 32, adjacent to the recess 31, contracts promptly after the recess 31 enlarges the cavity diameter, thereby controlling the slurry flow. The tooth 32 on the third sidewall 213 within the first control section W11 protrudes deep into the enlarged cavity, facilitating adjustment. The connecting bridge 22 within the second control section W12 does not protrude from the tooth 32.

[0067] The tooth 32 includes a flow control surface 321 located within the cavity of the opening 21, and the flow control surface 321 is arranged perpendicular to or inclined to the X direction. In this embodiment, the longer the protrusion length of the tooth 32, the greater the angle of inclination of its flow control surface 321, which is beneficial for controlling the flow of slurry.

[0068] The widened section W3 and the control section W1 are provided with integral settling grooves 24 on the upper and lower sides of the opening 21, forming an ink-draining ladder 25. The ink-draining ladder 25 includes two opposing longitudinal ribs 251, a transverse rib 252 connecting the two longitudinal ribs 251, and a through hole 253 located between adjacent transverse ribs 252. The ink-draining ladder 25 improves ink-draining performance.

[0069] A plurality of comb teeth 26 are arranged on both sides of the opening 21 within the printing groove 23. The comb teeth 26 extend from the side walls of the printing groove 23 toward the central opening 21 and are spaced apart from the opening 21 by a certain distance. In this embodiment, the plurality of comb teeth 26 are distributed symmetrically from the control section W1 to the regular section W2. The height of the comb teeth 26 is equal to the depth of the printing groove 23. In other embodiments, the height of the comb teeth 26 is less than or greater than the depth of the printing groove 23.

[0070] Several microstructures 111 are arrayed on the printing surface 11 of adjacent printing grid lines 2. In this embodiment, the microstructures 111 are recessed square grooves, and the depth of the square grooves is less than the depth of the printing grooves 23. The microstructures 111 can adjust the force of the doctor blade and the flow of the ink, thereby improving the printing quality.

[0071] One end of the uniformly widened section W32 is the third control section W13, while the other end is directly connected to the regular section W2 without a control section. The third control section W13 contains teeth 32. The uniformly widened section W32 and the third control section W13 are provided with settling grooves 24, forming a lower ink ladder 25. The third control section W13 has several comb-like teeth 26 extending towards both sides of the regular section W2.

[0072] Please continue to participate. Figures 1 to 9The screen printing body 1 includes a printing area 13, a flow adjustment area 14, a stress relief area 15, and an elastic area 16. The printing area 13 includes a left and right side along the X direction, and an upper and lower side along the Y direction. The flow adjustment area 14 is located on the left and right sides of the printing area 13 and is spaced apart from it. The stress relief area 15 is located on the upper and lower sides of the printing area 13 and is spaced apart from it. The elastic area 16 is located around the perimeter of the screen printing body 1. The flow adjustment area 14 contains an array of square micro-blind holes 141. The stress relief area 15 contains an array of stress relief grooves 151 extending along the X direction. The elastic area 16 contains a regular array of perforations 161. The average distance between the flow adjustment area 14 and the printing area 13 is greater than 100 μm and less than 5 mm. The width of the flow adjustment area 14 ranges from 3 mm to 100 mm. The micro-blind holes 141 can also be circular, triangular, polygonal, elliptical, or irregular in shape, and several micro-blind holes 141 are regularly or randomly distributed. The average aperture of the micro-blind holes 141 ranges from 20μm to 200μm, and the spacing between adjacent micro-blind holes 141 ranges from 20μm to 300μm. The flow adjustment zone 14 can effectively adjust the flow field of the ink during the printing process while ensuring the mechanical strength of the printing screen 100, thereby improving the uniformity and quality of printing.

[0073] Please refer to Figures 10 to 13 This utility model discloses another printing grid line 4 for a printing screen. The printing grid line 4 includes a printing groove 41, an opening 42 penetrating through the bottom of the printing groove 41, and a connecting bridge 43 located within the opening 42. The printing grid line 4 is provided with a first control section W41, a second control section W42, a regular section W5, and a gradually widening section W6. The printing groove 41 is provided with a plurality of comb-like parts 44 in the regular section W5 and the first control section W41. The flow control parts 5 of the first control section W41 and the second control section W42 are both provided with recesses 51 and teeth 52. In this embodiment, the connecting bridge 43 in the second control section W42 has protruding teeth 52. In this embodiment, the upper and lower sides of the printing grid line 4 are both recessed with settling grooves 45. The upper settling groove 451 settles from one side of the connecting bridge 43 and forms a step 431 on the connecting bridge 43. The lower settling groove 452 is located in the first control section W41, the gradually widening section W6, and the second control section W42. Along the X direction, the distribution length of the upper settling trough 451 is less than the distribution length of the lower settling trough 452, and along the Y direction, the distribution width of the upper settling trough 451 is greater than the distribution width of the lower settling trough 452.

[0074] Please refer to Figure 6 and Figure 7 Version 1 is a one-piece structure, which can be integrally molded, such as by electroforming, or it can be composed of two or more layers with no obvious interface or no interface between adjacent layers, thus being considered a one-piece structure. For other embodiments, please refer to... Figure 14 and Figure 15The screen printing body 6 includes a first layer 61 and a second layer 62 stacked together. The first layer 61 has a printing surface 611, and the second layer 62 has a substrate 621 opposite to the printing surface 611. The first layer 61 is a metal layer such as nickel or a nickel alloy, and the second layer is a metal layer such as nickel or a nickel alloy, or a polymer layer such as PI. The printing surface 611 has a plurality of arrayed microstructures 612, each microstructure being a square hole penetrating the first layer 61. In other embodiments, the depth of the square hole is less than the thickness of the first layer; or the microstructure protrudes from the printing surface. The width of the upper settling groove 631 is greater than the width of the lower settling groove 632.

[0075] Please refer to Figure 16 and Figure 17 This utility model discloses another printing grid line 7 of a printing screen. Figure 16 The image shows one segment. The printing grid line 7 includes a printing groove 71 and an opening 72 extending through the bottom of the printing groove 71. The printing grid line 7 is provided with a control segment W7, a regular segment W8, and a gradually widened segment W9, with the control segment 7 located between the regular segment W8 and the gradually widened segment W9. In this embodiment, the control segments W7 are respectively located at both ends of the gradually widened segment W9, and the control segments W7 at both ends are symmetrically arranged. In other embodiments, they are located only at one end or are asymmetrically arranged. The aperture of the opening 72 in the control segment W7 is gradually changed. A connecting bridge 73 is provided in the opening 72 in the control segment W7 and the gradually widened segment W9. The printing grid line 7 is provided with an integral settling groove 74 on the upper side of the control segment W7 and the gradually widened segment W9, forming an ink-feeding ladder 75. The ink-feeding ladder 75 includes two opposing longitudinal ribs 751, a transverse rib 752 connecting the two longitudinal ribs 751, and a through hole 753 located between adjacent transverse ribs 752, improving ink-feeding performance. The settling tank 74 includes an upper settling tank 741 and a lower settling tank (not shown). The upper settling tank 741 is recessed from the bottom of the printing tank 71. In other embodiments, the settling tank is located on the upper or lower side.

[0076] The opening 72 includes side edges 721 on both sides, and the flow control part 8 includes blocking strips 81 protruding from the side edges 721. The printing grid lines 7 extend along the X direction, and the blocking strips 81 are arranged perpendicular to the X direction. Several blocking strips 81 are distributed on both side edges 721 and arranged symmetrically. The blocking strips 81 are disposed in the printing tank 71, and extend from the side wall of the printing tank 71 toward the opening 72. The free ends of the blocking strips 81 protrude to the upper settling groove 741 and are suspended in the upper settling groove 741. The blocking strips 81 are distributed on both sides of the transverse ribs 752 and are distributed on the same straight line along the Y direction as the transverse ribs 752. The blocking strips 81 are used to actively regulate the ink flow and improve ink adhesion.

[0077] In other embodiments, please refer to Figure 18The free end of the blocking strip 82 just reaches the upper settling trough 742; please refer to... Figure 19 The free end of the blocking strip 83 does not reach the upper settling tank 743. The free end of the blocking strip is located near the side wall of the upper settling tank, which effectively controls the slurry.

[0078] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail above with reference to the accompanying drawings. Many specific details are set forth in the above description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described above, and those skilled in the art can make similar improvements without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed above. Furthermore, the technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; however, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0079] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A solar cell printing screen, characterized in that, It includes a screen frame and a screen body installed on the screen frame. The screen body is provided with a printing area, and a plurality of printing grid lines are arranged in the printing area. The printing grid lines are arranged through the screen body. At least one side of the printing area is provided with a flow adjustment area at intervals. The average distance between the flow adjustment area and the printing area is greater than 100μm. A plurality of micro blind holes are arranged in the flow adjustment area.

2. The solar cell printing screen according to claim 1, characterized in that, The width of the flow regulation zone ranges from 1mm to 100mm.

3. The printing screen according to claim 1, characterized in that, The micro-blind holes are circular, triangular, polygonal, elliptical, or irregular in shape, and a number of the micro-blind holes are regularly or randomly distributed.

4. The solar cell printing screen according to claim 1, characterized in that, The average diameter of the micro-blind holes ranges from 20μm to 200μm, and the spacing between adjacent micro-blind holes ranges from 20μm to 300μm.

5. The solar cell printing screen according to claim 1, characterized in that, The printed grid lines extend along the X direction, and a plurality of the printed grid lines are arranged at intervals along the Y direction perpendicular to the X direction. The flow adjustment area is provided on the left and right sides of the printing area along the X direction.

6. The solar cell printing screen according to claim 5, characterized in that, The printing area is provided with stress relief areas on both the upper and lower sides along the Y direction. The stress relief areas are spaced apart from the printing area. Several stress relief grooves extending along the X direction are arranged in the stress relief areas.

7. The solar cell printing screen according to claim 6, characterized in that, The edge of the mesh body is provided with an elastic zone, and several perforations are regularly or randomly distributed within the elastic zone.

8. The solar cell printing screen according to claim 7, characterized in that, The elastic zone is provided to enclose a ring around the perimeter of the mesh body, and the perforation is a circular hole.

9. The solar cell printing screen according to claim 1, characterized in that, The printed grid line includes an opening that penetrates the screen print body. At least one segment of the printed grid line is configured as a control segment, and the control segment includes a flow control portion that protrudes and / or retracts into the opening and / or out of the opening.

10. A solar cell, characterized in that, It includes a silicon wafer and conductive electrodes disposed on the silicon wafer, wherein the conductive electrodes are formed by printing using a solar cell printing screen as described in any one of claims 1 to 9.

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