A transfer device

Abstract

The application provides a kind of transfer printing device, it is related to photovoltaic technical field.The transfer printing device includes: in the first direction, feed tensioning wheel, slurry box and transfer printing wheel are sequentially arranged; conveying belt is sleeved on the transfer printing wheel and feed tensioning wheel; the inlet and outlet are opened in the slurry box; the slurry is contained in the slurry box; in the first direction, the linear velocity direction of the endpoint of the transfer printing wheel farthest from the feed tensioning wheel is perpendicular to the first direction; the side of the conveying belt away from the transfer printing wheel has a gap with the outlet, the size of the gap in the second direction is less than or equal to 30 μm; the slurry is adhered to the surface of the conveying belt, the slurry on the rest of the surface of the conveying belt is scraped off by the outlet, only the slurry at the contact position of the gap is reserved, the conveying belt with reserved slurry leaves the slurry box from the outlet and abuts on the solar cell, and the slurry reserved on the conveying belt is transferred on the solar cell to form a grid line.The application reduces the line width of the grid line and reduces the amount of slurry.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and in particular to a transfer printing device. Background Technology

[0002] Solar cells can convert solar energy into electrical energy, utilizing clean energy sources, and therefore have broad application prospects.

[0003] Currently, the apparatus used to prepare grid lines for collecting charge carriers in solar cells mainly includes a scraper and a screen. The scraper is used to apply the paste on the screen, and the part that passes through the screen forms the grid lines.

[0004] However, the grid lines formed by the above-mentioned devices have a large linewidth, such as greater than 30 μm, but the cost of the paste is high, resulting in a high cost of solar cells. Summary of the Invention

[0005] The present invention provides a transfer device aimed at solving the problem of large line width of the grid lines formed by existing transfer devices.

[0006] In a first aspect, the present invention provides a transfer printing apparatus, comprising: a feed tensioning roller, a paste box, and a transfer roller arranged sequentially in a first direction; a conveyor belt sleeved on the transfer roller and the feed tensioning roller; an inlet and an outlet provided on the paste box; and paste contained in the paste box.

[0007] In the first direction, the linear velocity direction at the end of the transfer wheel furthest from the feed tension wheel is perpendicular to the first direction; the side of the conveyor belt away from the transfer wheel has a gap with the outlet, and the size of the gap in the second direction is less than or equal to 30 μm; the second direction, the first direction, and the linear velocity direction are perpendicular to each other;

[0008] Driven by the transfer roller and the feed tension roller, the conveyor belt enters the slurry in the slurry box from the inlet. The slurry adheres to the surface of the conveyor belt. The outlet scrapes away the slurry at the remaining positions on the surface of the conveyor belt, leaving only the slurry at the position in contact with the gap. The conveyor belt with the slurry remaining leaves the slurry box from the outlet and comes into contact with the solar cell. The slurry remaining on the conveyor belt is transferred onto the solar cell to form grid lines.

[0009] In the transfer device of this invention, driven by the transfer roller and the feed tension roller, the conveyor belt enters the slurry box from the inlet and enters the slurry in the slurry box. The slurry has a certain viscosity, so it adheres to the surface of the conveyor belt. At the outlet of the slurry box, the slurry on the surface of the conveyor belt, except for the contact area with the gap, is scraped away, leaving only the slurry at the contact area with the gap. The conveyor belt with the slurry remaining leaves the slurry box from the outlet. The transfer roller presses the conveyor belt against the solar cell, transferring the slurry retained on the conveyor belt onto the solar cell to form grid lines. The slurry in contact with the aforementioned gap is printed onto the solar cell, and the portion in the second direction determines the width or linewidth of the grid lines. Therefore, the dimension of the aforementioned gap in the second direction is less than or equal to 30 μm, which limits the linewidth of the grid lines to less than or equal to 30 μm, thereby reducing the linewidth of the grid lines, reducing the amount of slurry used, and lowering the cost of the solar cell. Furthermore, the dimension of this gap in the second direction, less than or equal to 30 μm, is easy to set. Meanwhile, in the above-mentioned transfer device, continuous transfer can be achieved by the continuous movement of the conveyor belt, which is fast and efficient.

[0010] Optionally, the transfer device further includes: a dispensing tube and a dispensing machine; the dispensing tube connects the slurry box and the dispensing machine.

[0011] Optionally, the size of the gap in the second direction is greater than or equal to 2 μm.

[0012] Optionally, the transfer device further includes a cleaning mechanism and a drying mechanism; along the forward direction of the conveyor belt, the cleaning mechanism and the drying mechanism are located after the transfer wheel and before the feed tension wheel;

[0013] The cleaning mechanism is used to clean the conveyor belt after the transfer printing.

[0014] The drying mechanism is used to dry the conveyor belt after cleaning.

[0015] Optionally, the transfer device further includes at least one enlarged space tensioning wheel, and the conveyor belt is sequentially sleeved on the transfer wheel, the enlarged space tensioning wheel and the feed tensioning wheel.

[0016] Optionally, the number of transfer wheels is two; the line connecting the centers of the two transfer wheels is parallel to the linear velocity direction, and the distance between the centers of the two transfer wheels is greater than or equal to the length of a grid line, less than or equal to the size of a solar cell in the linear velocity direction, and the sum of the distance between adjacent solar cells in the linear velocity direction.

[0017] Optionally, the conveyor belt is closedly fitted onto the transfer wheel and the feed tension wheel.

[0018] Optionally, the slurry box has no other openings except for the inlet communicating with the injection pipe, the inlet and the outlet;

[0019] The cross-sectional area of ​​the inlet is greater than the cross-sectional area of ​​the conveyor belt, and the difference between the two is 10 μm² to 100 μm²; the cross-section is perpendicular to the first direction.

[0020] Optionally, during the transfer process, the injection machine pressurizes the paste box through the injection pipe, and the pressure is 1.1 to 2 times the atmospheric pressure.

[0021] Optionally, the portion of the conveyor belt passing through the slurry box has an angle of -30° to 30° with the first direction.

[0022] Optionally, the variance of the cross-section dimensions at various points along the entire conveyor belt in the direction perpendicular to the linear velocity is less than or equal to 1 μm².

[0023] Optionally, the cross-sectional shape of the conveyor belt is one of the following: triangle, rectangle, trapezoid, polygon with more than 4 sides, circle, and ellipse; the cross-section is perpendicular to the first direction.

[0024] Optionally, when the cross-sectional shape of the conveyor belt is a triangle, rectangle, trapezoid, or polygon with more than 4 sides, the corners of the cross-section of the conveyor belt are chamfered.

[0025] Optionally, the cross-sectional area of ​​the outlet is greater than the cross-sectional area of ​​the conveyor belt, and the difference between the two is less than or equal to 900 μm2; the cross-section is perpendicular to the first direction.

[0026] Optionally, the conveyor belt is made of diamond wire;

[0027] Alternatively, the material of the conveyor belt may be selected from: alloys, and / or, carbon fiber.

[0028] Optionally, in the first direction, the transfer wheel is closer to the Earth's center than the feed tension wheel. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1A schematic diagram of the structure of a transfer device according to an embodiment of the present invention is shown;

[0031] Figure 2 A schematic diagram of another transfer device in an embodiment of the present invention is shown;

[0032] Figure 3 A schematic diagram of another transfer device according to an embodiment of the present invention is shown;

[0033] Figure 4 A schematic diagram of the first cross-section in an embodiment of the present invention is shown;

[0034] Figure 5 A schematic diagram of the second cross-section in an embodiment of the present invention is shown;

[0035] Figure 6 A schematic diagram of the third cross-section in an embodiment of the present invention is shown;

[0036] Figure 7 A schematic diagram of the fourth cross-section in an embodiment of the present invention is shown;

[0037] Figure 8 A schematic diagram of the fifth cross-section in an embodiment of the present invention is shown.

[0038] Explanation of the attached drawing numbers:

[0039] 1-Transfer roller, 2-Solar cell, 3-Expanding space tension roller, 4-Feed tension roller, 5-Slurry box, 6-Slurry, 7-Conveyor belt, 8-Injection pipe, 9-Injection machine. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] This invention provides a transfer device, Figure 1 A schematic diagram of a transfer device according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of another transfer device in an embodiment of the present invention is shown. Figure 3 A schematic diagram of another transfer device according to an embodiment of the present invention is shown. (Refer to...) Figures 1 to 3 The transfer device may include: a transfer wheel 1, a feed tension wheel 4, a conveyor belt 7, and a paste box 5. Figures 1 to 3In the diagram, L1 represents the first direction. Along the first direction L1, the feed tensioning roller 4, the paste box 5, and the transfer roller 1 are arranged sequentially. Whether their geometric centers are collinear is not specifically limited; it is sufficient that they are arranged in this manner along the first direction. For example, Figure 1 In the middle, the slurry box 5 can be tilted to the left or right.

[0042] Conveyor belt 7 is mounted on transfer wheel 1 and feed tension wheel 4. The paste box 5 has an inlet and an outlet. In the first direction L1, the inlet is closer to the feed tension wheel 4, and the outlet is closer to the printing wheel 1. As shown in the figure, the first direction L1 is vertical, with the inlet higher and the outlet lower. The paste box 5 contains paste 6, which can be copper paste, silver paste, aluminum paste, or other grid pastes. This grid paste typically has a certain viscosity.

[0043] In the aforementioned first direction L1, the end of the transfer roller 1 furthest from the feed tension roller 4 is... Figures 1 to 3 In the middle, there is the lowest point of the transfer roller 1. This point will bring the conveyor belt 7 into contact with the solar cell 2. In the aforementioned first direction L1, the linear velocity direction of the point on the transfer roller 1 furthest from the feed tension wheel 4 is... Figures 1 to 3 The middle direction is L2 from left to right, and... Figures 1 to 3 The first direction from top to bottom, L1, is perpendicular.

[0044] Figure 4 A schematic diagram of the first cross-section in an embodiment of the present invention is shown. Figure 5 A schematic diagram of the second cross-section in an embodiment of the present invention is shown. Figure 6 A schematic diagram of the third cross-section in an embodiment of the present invention is shown. Figure 7 A schematic diagram of the fourth cross-section in an embodiment of the present invention is shown. Figure 8 A schematic diagram of the fifth cross-section in an embodiment of the present invention is shown. All cross-sections mentioned in this invention are perpendicular to the first direction L1. Figures 4 to 8 The cross sections shown are all perpendicular to the aforementioned first direction L1, and are all... Figures 1 to 3 The cross section at position AA in the middle.

[0045] Reference Figures 4 to 8 The conveyor belt 7, located away from the transfer wheel 1, has a gap between itself and the outlet, where the slurry 6 is present. The dimension of the gap in the second direction L3 is less than or equal to 30 μm. Here, the second direction L3, the first direction L1, and the linear velocity direction L2 are perpendicular to each other. More specifically, the cross-section is parallel to the plane defined by the second direction L3 and the linear velocity direction L2, where the second direction L3 is a direction perpendicular to the linear velocity direction L2 on the cross-section.

[0046] Driven by the transfer roller 1 and the feed tension roller 4, the conveyor belt 7 enters the slurry box 5 from the inlet and enters the slurry 6 in the slurry box 5. The slurry 6 has a certain viscosity, so it adheres to the surface of the conveyor belt 7. At the outlet of the slurry box 5, the slurry 6 on the surface of the conveyor belt 7 is scraped away from all positions except the gap contact position, leaving only the slurry 6 at the gap contact position. The conveyor belt 7 with the slurry 6 remaining leaves the slurry box 5 from the outlet. The transfer roller 1 presses the conveyor belt 7 against the solar cell 2, so that the slurry 6 remaining on the conveyor belt 7 is transferred onto the solar cell 2 to form grid lines. The paste 6 in contact with the aforementioned gap is printed onto the solar cell 2. The portion in the second direction L3 determines the width or linewidth of the grid lines. Therefore, if the size of the aforementioned gap in the second direction L3 is less than or equal to 30 μm, the linewidth of the grid lines is limited to less than or equal to 30 μm, thereby reducing the linewidth of the grid lines, reducing the amount of paste 6 used, and lowering the cost of the solar cell 2. Furthermore, setting the size of the gap in the second direction L3 to be less than or equal to 30 μm is also easy. Simultaneously, in the above-mentioned transfer device, the continuous movement of the conveyor belt 7 enables continuous transfer, resulting in fast transfer speed and high efficiency.

[0047] For example, the size of the aforementioned gap in the second direction L3 can be 1μm, or 3μm, or 5.1μm, or 7μm, or 11μm, or 15μm, or 20μm, or 23μm, or 30μm.

[0048] It should be noted that the side wall at the outlet of the slurry box 5 will scrape away all the slurry 6 on the surface of the conveyor belt 7 except for the contact position with the gap, leaving only the slurry 6 at the contact position with the gap. It should also be noted that the type of solar cell is not specifically limited in this invention; it can be a bifacial cell, a single-sided cell, etc. A bifacial cell refers to a cell with grid lines on both the light-facing and back-facing sides, while a single-sided cell refers to a cell with grid lines only on the back-facing side. The grid lines here can be current collector grid lines for collecting electrons or current collector grid lines for collecting holes.

[0049] Here, the forward direction of the solar cell 2 can be the same as the linear velocity direction L2 at the end of the transfer roller 1 furthest from the feed tension roller 4 in the aforementioned first direction L1. After the paste 6 retained on the conveyor belt 7 is transferred to the solar cell 2, the conveyor belt 7 and the solar cell 2 can be separated by speed difference or position difference, etc., without specific limitations.

[0050] Optionally, in the first direction L1, the transfer wheel 1 is closer to the center of the earth than the feed tension wheel 4, so that the paste 6 retained on the conveyor belt 7 moves from the paste box 5 to the solar panel 2 in a direction that is roughly parallel to the direction of gravity acting on the paste 6, making it less likely for the paste 6 to fall off the conveyor belt 7, thus improving the integrity of the grid line shape.

[0051] Optional, refer to Figures 1 to 3 The transfer device may also include: a filling pipe 8 and a filling machine 9. The filling pipe 8 connects the paste box 5 and the filling machine 9. The filling machine 9 injects paste into the paste box 5 through the filling pipe 8, thereby automatically and continuously filling the paste box 5, ensuring the continuity of the transfer.

[0052] Optionally, the size of the aforementioned gap in the second direction L3 is greater than or equal to 2μm and less than or equal to 30μm, which means that the linewidth of the gate line is limited to a range of greater than or equal to 2μm and less than or equal to 30μm. This makes it easy to set, and the resulting linewidth of the gate line is more suitable, resulting in a better effect of collecting charge carriers.

[0053] For example, the size of the aforementioned gap in the second direction L3 can be 2μm, or 4μm, or 7.3μm, or 9μm, or 13μm, or 15μm, or 19μm, or 22μm, or 30μm.

[0054] Optionally, the transfer device may also include a cleaning mechanism and a drying mechanism (not shown in the figure). Along the forward direction of the conveyor belt 7, the cleaning mechanism and the drying mechanism are located sequentially after the transfer roller 1 and before the feed tension roller 4. The cleaning mechanism is used to clean the conveyor belt 7 after the transfer, removing any residual paste or impurities that may remain on the conveyor belt 7 after the transfer, preventing these impurities from being carried into the paste box 5, and avoiding any adverse effects on the next transfer. The drying mechanism is used to dry the cleaned conveyor belt 7, preventing cleaning agents from being carried into the paste box 5.

[0055] For example, Figures 1 to 3 In this system, the conveyor belt 7 moves counterclockwise. Along this counterclockwise direction, the cleaning mechanism and the drying mechanism are located sequentially after the transfer roller 1 and before the feed tension roller 4. After the transfer roller 1 completes the transfer, as the conveyor belt 7 moves counterclockwise, the cleaning mechanism cleans any residual slurry or impurities from the conveyor belt 7. Then, the drying mechanism dries the cleaned conveyor belt 7 to prevent cleaning agents from being carried into the slurry box 5. The conveyor belt 7 continues its counterclockwise movement until it reaches the feed tension roller 4, preparing for the next slurry adsorption.

[0056] It should be noted that the conveyor belt 7 moves along the feed tensioning wheel 4, then enters the inlet of the slurry box 5, leaves the slurry box from the outlet of the slurry box 5, and then transfers the slurry onto the solar cell at the transfer wheel 1. Figures 1 to 3 In the case where the slurry box 5 is located on the right side, the forward direction of the conveyor belt 7 is clockwise.

[0057] Optional, refer to Figure 2 , Figure 3 The transfer device may further include: at least one space-expanding tensioning roller 3, with the conveyor belt 7 sequentially mounted on the transfer roller 1, the space-expanding tensioning roller 3, and the feed tensioning roller 4. The space-expanding tensioning roller 3, located between the transfer roller 1 and the feed tensioning roller 4, increases the travel distance of the conveyor belt 7 after one transfer and before the next, thereby providing more space for the cleaning and drying mechanisms. The number of space-expanding tensioning rollers 3 can be greater than or equal to one; the specific number is not limited.

[0058] It should be noted that in this invention, the transfer wheel 1, the space-expanding tension wheel 3, the feeding tension wheel 4, the cleaning mechanism, and the drying mechanism can all be made of wear-resistant materials, and no specific material is limited.

[0059] Optional, refer to Figure 3 The device uses two transfer rollers 1, which increases the contact area between the paste 6 on the conveyor belt 7 and the solar cell 2, allowing for a single paste transfer and shortening the transfer time. The line connecting the centers of the two transfer rollers 1 is parallel to the linear velocity direction L2, and the distance between the centers of the two transfer rollers 1 is greater than or equal to the length of a grid line, less than or equal to the dimension of a solar cell 2 in the linear velocity direction L2, and the sum of the distance between adjacent solar cells 2 in the linear velocity direction L2. This allows for the printing of a complete grid line in one operation, with both transfer rollers 1 printing grid lines simultaneously on a single solar cell 2. The center of the transfer roller 1 can refer to its geometric center. This transfer device can achieve continuous grid line transfer, so the solar cells 1 are also continuously supplied along the linear velocity direction L2. Here, the distance between adjacent solar cells 2 in the linear velocity direction L2 refers to the distance between two adjacent solar cells 2 in the linear velocity direction L2 among multiple continuously supplied solar cells.

[0060] Optional, refer to Figures 1 to 3 The conveyor belt 7 is closed and fitted onto the transfer wheel 1 and the feed tension wheel 4, thus enabling continuous transfer printing with high efficiency.

[0061] Optional, refer to Figures 1 to 3In the slurry box 5, apart from the inlet connected to the injection pipe 8 and the inlet and outlet of the conveyor belt 7, there are no other openings. This better ensures the stability of the pressure inside the slurry box 5 and prevents the components of the slurry 6 from being contaminated or affected by air. The cross-sectional area of ​​the inlet of the slurry box 5 is larger than the cross-sectional area of ​​the conveyor belt 7, which facilitates the movement of the conveyor belt 7. Here, the cross-section of the inlet and the cross-section of the conveyor belt 7 are both perpendicular to the aforementioned first direction L1, and the difference between the two is 10μm2 to 100μm2. On the one hand, the inlet is smaller, which better ensures the stability of the pressure inside the slurry box 5 and prevents the components of the slurry 6 from being contaminated or affected by air. On the other hand, the inlet is not too small, which ensures the smooth movement of the conveyor belt 7.

[0062] For example, the difference between the cross-section of the inlet of the slurry box 5 and the cross-section of the conveyor belt 7 can be 10 μm2, or 15 μm2, or 31 μm2, or 48 μm2, or 55 μm2, or 63 μm2, or 81 μm2, or 100 μm2.

[0063] Optionally, during the transfer process, the injection machine 9 pressurizes the paste box 5 through the injection pipe 8. The pressure is 1.1 to 2 times the atmospheric pressure, so that the pressure in the paste box 5 is appropriate, and the paste 6 adhering to the conveyor belt 7 is full and uniform.

[0064] For example, during the transfer process, the injection machine 9 pressurizes the paste box 5 through the injection pipe 8. The pressure can be 1.1 times atmospheric pressure, or 1.1 times atmospheric pressure, or 1.3 times atmospheric pressure, or 1.5 times atmospheric pressure, or 1.7 times atmospheric pressure, or 1.8 times atmospheric pressure, or 1.9 times atmospheric pressure, or 2 times atmospheric pressure.

[0065] Optionally, the portion of the conveyor belt 7 passing through the paste box 5 forms an angle of -30° to 30° with the first direction L1. This suitable angle ensures that the paste 6 adhering to the conveyor belt 7 is full and uniform. When the portion of the conveyor belt 7 passing through the paste box 5 forms an angle of non-zero with the first direction L1, the movement trajectory of the conveyor belt 7 is longer, which can cause the paste 6 in different directions or positions to move and adhere more evenly. This can reduce the problem of uneven composition between the bottom and top of the paste box 5 after prolonged use and avoid inconsistent composition of the transferred grid lines.

[0066] For example, the angle between the portion of the conveyor belt 7 that passes through the slurry box 5 and the first direction L1 can be -30°, -20°, -15°, -3°, 0°, 8°, 10°, 19°, or 30°.

[0067] Optionally, the variance of the cross-sectional dimensions at various points along the entire conveyor belt 7 in the direction perpendicular to the linear velocity L2 is less than or equal to 1 μm². This smaller variance ensures that the difference in dimensions of the cross-sections at various points along the linear velocity L2 is smaller, guaranteeing that the linewidths of the transferred grid lines are essentially equal and uniform. Here, the cross-section is perpendicular to the aforementioned first direction L1. For example, the variance of the cross-sectional dimensions at various points along the entire conveyor belt 7 in the direction perpendicular to the linear velocity L2 can be 0, 0.1 μm², 0.21 μm², 0.33 μm², 0.5 μm², 0.71 μm², 0.83 μm², or 1 μm².

[0068] Optionally, the cross-sectional shape of the conveyor belt 7 can be one of the following: triangle, rectangle, trapezoid, polygon with more than 4 sides, circle, and ellipse. The shape of the conveyor belt 7 is flexible and diverse. The cross-section of the conveyor belt 7 is perpendicular to the aforementioned first direction L1.

[0069] For example, refer to Figure 4 The cross-sectional shape of conveyor belt 7 is trapezoidal. Figure 4 In the middle, the side of the conveyor belt 7 away from the transfer wheel 1 has a gap with the outlet of the paste box 5, and paste is contained in the gap. The dimension of the gap in the second direction L3 is... Figure 4 In the diagram, the length of the right base of the triangular paste is the side length of the left base of the trapezoidal cross-section of the conveyor belt 7 that contacts the paste. This side length is less than or equal to 30 μm. During the transfer process, the line width of the transfer grid is determined by this dimension. As the paste passes through the outlet of the paste box 5, the paste in other parts of the trapezoidal cross-section of the conveyor belt 7 is scraped off by the side wall of the outlet.

[0070] For example, Figure 5 In the middle, the cross-sectional shape of conveyor belt 7 is trapezoidal, with chamfered corners. Figure 5 In the middle, the side of the conveyor belt 7 away from the transfer wheel 1 has a gap with the outlet of the paste box 5, and paste 6 is contained in the gap. The dimension of the gap in the second direction L3 is... Figure 5 In the process of passing through the outlet of the ink box 5, the length of the right base of the chamfered triangular ink 6 is the side length of the left base of the trapezoidal cross-section of the conveyor belt 7 that contacts the ink. This side length is less than or equal to 30 μm, and the line width of the transfer grid lines is determined by this dimension. During the process of passing through the outlet of the ink box 5, the ink in other parts of the trapezoidal cross-section of the conveyor belt 7 will be scraped off by the side wall of the outlet.

[0071] For example, Figure 6 In the middle, the cross-sectional shape of the conveyor belt 7 is trapezoidal, with rounded chamfers at the corners. Figure 6In the middle, the side of the conveyor belt 7 away from the transfer wheel 1 has a gap with the outlet of the paste box 5, and paste 6 is contained in the gap. The dimension of the gap in the second direction L3 is... Figure 6 In the process of transferring ink from the trapezoidal cross-section of the conveyor belt 7 to the right base of the triangular ink with rounded chamfers, the length of the right base of the triangular ink has the same side length as the left base of the trapezoidal cross-section of the conveyor belt 7 that contacts the ink 6. This side length is less than or equal to 30 μm. The line width of the transferred grid lines is determined by this dimension. During the process of transferring ink from the outlet of the ink box 5, the ink in other parts of the trapezoidal cross-section of the conveyor belt 7 will be scraped off by the side wall of the outlet.

[0072] For example, Figure 7 In the middle, the cross-sectional shape of conveyor belt 7 is elliptical. Figure 7 In the middle, the side of the conveyor belt 7 away from the transfer wheel 1 has a gap with the outlet of the paste box 5, and paste 6 is contained in the gap. The dimension of the gap in the second direction L3 is... Figure 7 In the middle, the dimension of the right arc of the crescent-shaped part in the second direction L3, that is, the dimension of the left arc of the elliptical cross section of the conveyor belt 7 that contacts the slurry in the second direction L3, is less than or equal to 30μm. The line width of the transfer grid line is determined by this dimension. During the process of passing through the outlet of the slurry box 5, the slurry in other parts of the elliptical cross section of the conveyor belt 7 will be scraped off by the side wall of the outlet.

[0073] For example, Figure 8 The cross-sectional shape of the conveyor belt 7 is trapezoidal with rounded corners. The side of the conveyor belt 7 facing away from the transfer wheel 1 has a gap with the outlet of the paste box 5. Paste 6 is contained within this gap. The dimension of the gap in the second direction L3 is... Figure 8 In the trapezoidal paste 6, the longer bottom side of the left portion is less than or equal to 30μm. The line width of the transfer grid is determined by this dimension. During the process of passing through the outlet of the paste box 5, the paste of other parts of the elliptical cross-section of the conveyor belt 7 will be scraped off by the side wall of the outlet.

[0074] Optionally, if the cross-sectional shape of the conveyor belt 7 is triangular, rectangular, trapezoidal, or a polygon with more than four sides, the corners of the cross-section of the conveyor belt 7 are chamfered. These chamfers can be rounded or 45° chamfers, etc., and the specific form of the chamfer is not limited. The chamfered corners of the conveyor belt 7 facilitate processing, and since the shape of the outlet of the slurry box 5 needs to match the shape of the cross-section of the conveyor belt 7, the chamfered corners of the conveyor belt 7 also facilitate the processing of the outlet.

[0075] For example, refer to Figure 5 , Figure 6 , Figure 8The cross-section of the conveyor belt 7 is trapezoidal, and the corners of the cross-section of the conveyor belt 7 are chamfered.

[0076] Optionally, the cross-sectional area of ​​the outlet of the paste box 5 is larger than the cross-sectional area of ​​the conveyor belt 7, with the excess being the aforementioned gap. The difference between the two is less than or equal to 900 μm², resulting in a grid line height × linewidth range that is also less than or equal to 900 μm², covering the height × linewidth range of most common grid lines. Consequently, this transfer device can transfer most common grid lines. The cross-section of the outlet of the paste box 5 and the cross-section of the conveyor belt 7 are both perpendicular to the aforementioned first direction L1.

[0077] Optionally, the conveyor belt 7 is made of diamond wire. Alternatively, the material of the conveyor belt 7 may be selected from: alloys, and / or carbon fiber. Conveyor belts 7 formed from the above materials are wear-resistant, not easily broken, and have a long service life; moreover, these materials are readily available. The specific composition of the alloy is not limited. For example, the alloy here may be an alloy formed by adding manganese to stainless steel, or an alloy formed by adding zinc to stainless steel, etc.

[0078] It should be noted that, in this document, the terms "comprising," "including," 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. Unless otherwise specified, 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.

[0079] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A transfer device, characterized in that, include: In the first direction, the feed tensioning roller, the paste box, and the transfer roller are arranged sequentially; The conveyor belt is fitted onto the transfer wheel and the feed tension wheel; The slurry box has an inlet and an outlet; the slurry box contains slurry. In the first direction, the linear velocity direction at the end of the transfer wheel furthest from the feed tension wheel is perpendicular to the first direction; the side of the conveyor belt away from the transfer wheel has a gap with the outlet, and the size of the gap in the second direction is less than or equal to 30 μm; the second direction, the first direction, and the linear velocity direction are perpendicular to each other; Driven by the transfer roller and the feed tension roller, the conveyor belt enters the slurry in the slurry box from the inlet. The slurry adheres to the surface of the conveyor belt. The outlet scrapes away the slurry at the remaining positions on the surface of the conveyor belt, leaving only the slurry at the position in contact with the gap. The conveyor belt with the slurry remaining leaves the slurry box from the outlet and comes into contact with the solar cell. The slurry remaining on the conveyor belt is transferred onto the solar cell to form grid lines.

2. The transfer device according to claim 1, characterized in that, Also includes: The injection pipe and the injection machine are connected; the injection pipe connects the slurry box and the injection machine.

3. The transfer apparatus according to claim 1, characterized in that, The size of the gap in the second direction is greater than or equal to 2 μm.

4. The transfer apparatus according to claim 1, characterized in that, Also includes: A cleaning mechanism and a drying mechanism; along the forward direction of the conveyor belt, the cleaning mechanism and the drying mechanism are located after the transfer wheel and before the feed tension wheel; The cleaning mechanism is used to clean the conveyor belt after the transfer printing. The drying mechanism is used to dry the conveyor belt after cleaning.

5. The transfer apparatus according to claim 4, characterized in that, Also includes: At least one enlarged space tensioning roller, and the conveyor belt is sequentially mounted on the transfer roller, the enlarged space tensioning roller and the feed tensioning roller.

6. The transfer apparatus according to any one of claims 1 to 5, characterized in that, The number of transfer wheels is two; the line connecting the centers of the two transfer wheels is parallel to the linear velocity direction, and the distance between the centers of the two transfer wheels is greater than or equal to the length of a grid line, and less than or equal to the sum of the size of a solar cell in the linear velocity direction and the spacing between adjacent solar cells in the linear velocity direction.

7. The transfer apparatus according to any one of claims 1 to 5, characterized in that, The conveyor belt is closedly fitted onto the transfer wheel and the feed tensioning wheel.

8. The transfer apparatus according to claim 2, characterized in that, The slurry box has no openings other than the inlet connected to the injection pipe, the inlet, and the outlet. The cross-sectional area of ​​the inlet is greater than the cross-sectional area of ​​the conveyor belt, and the difference between the two is 10 μm² to 100 μm²; the cross-section is perpendicular to the first direction.

9. The transfer apparatus according to claim 8, characterized in that, During the transfer process, the injection machine pressurizes the paste box through the injection pipe, and the pressure is 1.1 to 2 times the atmospheric pressure.

10. The transfer apparatus according to any one of claims 1 to 5, 8, and 9, characterized in that, The portion of the conveyor belt passing through the slurry box forms an angle of -30° to 30° with the first direction.

11. The transfer apparatus according to any one of claims 1 to 5, 8, and 9, characterized in that, Throughout the entire conveyor belt, the variance of the cross-section dimensions at various points in the direction perpendicular to the linear velocity is less than or equal to 1 μm².

12. The transfer apparatus according to any one of claims 1 to 5, 8, and 9, characterized in that, The cross-sectional shape of the conveyor belt is one of the following: triangle, rectangle, trapezoid, polygon with more than 4 sides, circle, and ellipse; the cross-section is perpendicular to the first direction.

13. The transfer apparatus according to claim 12, characterized in that, When the cross-sectional shape of the conveyor belt is a triangle, rectangle, trapezoid, or polygon with more than 4 sides, the corners of the cross-section of the conveyor belt are chamfered.

14. The transfer apparatus according to any one of claims 1 to 5, 8, and 9, characterized in that, The area of ​​the cross-section of the outlet is greater than the area of ​​the cross-section of the conveyor belt, and the difference between the two is less than or equal to 900 μm2; the cross-section is perpendicular to the first direction.

15. The transfer apparatus according to any one of claims 1 to 5, 8, and 9, characterized in that, The conveyor belt is made of diamond wire; Alternatively, the material of the conveyor belt may be selected from: alloys, and / or, carbon fiber.

16. The transfer apparatus according to any one of claims 1 to 5, 8, and 9, characterized in that, In the first direction, the transfer wheel is closer to the Earth's center than the feed tension wheel.

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