Laser transfer printing film, photovoltaic transfer printing system and solar cell

Abstract

The utility model relates to a laser transfer printing film, a photovoltaic transfer printing system and a solar cell, the laser transfer printing film is used for laser transfer printing of grid lines on a photovoltaic cell, the laser transfer printing film comprises a transfer printing film body, and the transfer printing film body comprises a first side face and a second side face which are oppositely arranged. A plurality of grid line grooves are formed in the first side face at intervals in the first direction, extend in the second direction and are used for being filled with slurry; wherein the size of a groove opening of the grid line groove is smaller than the size of the position, with the largest groove width, of the grid line groove, the first direction and the second direction are orthogonal, and the transfer printing film body extends in the first direction and the second direction. The notch of the grid line groove is set to be smaller than the size of the maximum position of the groove width of the grid line groove, so that the line width of the part, in contact with the battery piece, of the grid line formed on the battery piece is smaller than the size of the maximum position of the grid line after the slurry is transferred to the battery piece, and the shading area of the grid line on the battery piece is reduced while the electrical performance is ensured; and the photoelectric conversion efficiency of the cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, in particular to a laser transfer film, a photovoltaic transfer system and a solar cell. Background Art

[0002] At present, the metallization process of solar cells is developing towards the direction of narrow line width. The narrower the grid line width, the less light shielding, which is beneficial to improving the current generation of solar cells. There are some methods for the metallization scheme of solar cells, such as screen printing, laser transfer, electroplating, etc. Laser transfer is a non-contact printing method. By irradiating the paste filled in the grooves of the transfer film with laser, the surface of the paste dries instantly, and the organic matter volatilizes, so that the grid lines fall on the surface of the silicon wafer, thus forming the electrodes. The grid line width of laser transfer is relatively small, and the aspect ratio of the grid line height is greater than that of screen printing. However, the grid line width after laser transfer in the related technology still cannot meet the ideal requirements, thereby affecting the photoelectric conversion efficiency. Summary of the Utility Model

[0003] Based on this, in view of the technical problem that the grid line width is relatively wide after laser transfer in the related technology, resulting in low photoelectric conversion efficiency, it is necessary to provide a laser transfer film, a photovoltaic transfer system and a solar cell.

[0004] A laser transfer film is used for laser-transferring grid lines on a photovoltaic cell. The laser transfer film includes:

[0005] A transfer film body, the transfer film body includes a first side and a second side arranged oppositely. A plurality of grid grooves are formed on the first side at intervals along a first direction, and the grid grooves extend along a second direction. The grid grooves are used for filling paste;

[0006] Wherein, the notch size of the grid groove is smaller than the size of the position with the maximum groove width of the grid groove. The first direction and the second direction are orthogonal, and the transfer film body extends along the first direction and the second direction.

[0007] In one embodiment, a plurality of the grid grooves are arranged in an array on the first side to form multiple groups of the grid grooves arranged at intervals along the second direction on the first side.

[0008] In one embodiment, the cross-sectional shape of the grid groove is configured as a semicircle.

[0009] In one embodiment, the inner diameter of the grid groove is between 15 - 25 um, and the notch width of the grid groove is between 10 - 20 um.

[0010] A photovoltaic transfer system, the photovoltaic transfer system includes:

[0011] A base;

[0012] A supporting platform, movably disposed on the base, and used for supporting the battery sheet;

[0013] A frame, slidably connected to the base and located above the supporting platform, the frame is used to support the laser transfer film as described above, and the frame can drive the laser transfer film to contact the battery sheet;

[0014] A laser module is disposed on the base and located above the frame, and the laser emitted by the laser module can irradiate the laser transfer film;

[0015] A stripping scraper is slidably connected to the frame. The stripping scraper can be pressed against the second side of the laser transfer film. The slurry in the grid line groove is separated from the grid line groove and transferred to the battery cell under the action of the stripping scraper.

[0016] In one of the embodiments, first guide rails are provided at both ends of the frame along the second direction, and both ends of the stripping scraper are slidably connected to the first guide rails respectively, and the first guide rails extend along the first direction.

[0017] In one embodiment, the photovoltaic transfer system further comprises:

[0018] A filling scraper, wherein the filling scraper is movably disposed on the frame and is located below the laser transfer film. When the filling scraper moves relative to the frame along the first direction, the filling scraper can be pressed against the first side surface to fill the slurry in the filling scraper into the gate line groove.

[0019] In one embodiment, the filler scraper is a closed internal circulation scraper.

[0020] In one embodiment, second guide rails are provided at both ends of the frame along the second direction on one side facing the support platform, and both ends of the filler scraper are slidably connected to the two second guide rails respectively, and the second guide rails extend along the first direction.

[0021] A solar cell, comprising:

[0022] A battery cell is provided with a plurality of gate lines, the gate lines are formed by transfer from the laser transfer film as described above; the plurality of gate lines are spaced apart along the first direction, the gate lines extend along the second direction, and the line width of the position where the gate lines contact the battery cell is smaller than the size of the position where the line width of the gate lines is the largest.

[0023] Beneficial effects of the utility model:

[0024] The utility model discloses a laser transfer film for transferring grid lines onto a photovoltaic cell. By providing a plurality of grid line grooves on the second side surface, the grid line grooves are used to fill the paste. After being irradiated by a laser, the surface of the paste dries instantaneously, and the organic matter volatilizes, causing the grid lines formed by the paste to fall onto the surface of the cell, thereby forming grid lines. In this application, the notch of the grid line groove is set to be smaller than the size of the position with the maximum groove width of the grid line groove, so that after the paste is transferred onto the cell, the line width of the part of the grid line in contact with the cell on the cell is smaller than the size of the position with the maximum grid line width, thereby reducing the light shielding area of the grid line on the cell while ensuring the electrical performance, which is beneficial to improving the photoelectric conversion efficiency of the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 7 is a schematic structural view of the first side surface of the laser transfer film provided by an embodiment of the utility model;

[0026] Figure 2 FIG. 11 is a cross-sectional view of the laser transfer film provided by an embodiment of the utility model;

[0027] Figure 3 FIG. 15 is a schematic view of the filling blade in the photovoltaic transfer system provided by an embodiment of the utility model when filling the laser transfer film;

[0028] Figure 4 FIG. 19 is a schematic view of the laser module in the photovoltaic transfer system provided by an embodiment of the utility model when irradiating the laser transfer film with a laser;

[0029] Figure 5 FIG. 23 is a schematic view of the stripping blade in the photovoltaic transfer system provided by an embodiment of the utility model when stripping the laser transfer film.

[0030] REFERENCE SIGNS:

[0031] Transfer film body 100; Grid line groove 110; Cell 200; Laser module 300; Stripping blade 400; Filling blade 500; First direction X; Second direction Y. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to make the above objects, features, and advantages of the utility model more obvious and understandable, the following detailed description of the specific embodiments of the utility model will be made with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the utility model. Therefore, the utility model is not limited by the specific embodiments disclosed below.

[0033] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0035] In the present utility model, unless otherwise clearly specified and defined, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0036] In the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0037] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0038] Referring to Figure 1 and Figure 2 , an embodiment of the present utility model provides a laser transfer film for laser-transferring grid lines on a photovoltaic cell 200. The laser transfer film includes a transfer film body. The transfer film body 100 includes a first side and a second side disposed opposite to each other. A plurality of grid line grooves 110 are formed on the first side at intervals along a first direction X. The grid line grooves 110 extend along a second direction Y. The grid line grooves 110 are used for filling the paste. Wherein, the notch size of the grid line grooves 110 is smaller than the size at the position where the maximum groove width of the grid line grooves 110 is located. The first direction X and the second direction Y are orthogonal, and the transfer film body 100 extends along the first direction X and the second direction Y.

[0039] The present technical solution provides a laser transfer film for laser-transferring grid lines on a photovoltaic cell 200. By providing a plurality of grid line grooves 110 on the second side, the grid line grooves 110 are used for filling the paste. After being irradiated by laser, the surface of the paste dries instantly, and the organic matter volatilizes, so that the grid lines formed by the paste fall on the surface of the cell 200, thereby forming grid lines. In the present application, the notch of the grid line grooves 110 is set to be smaller than the size at the position where the maximum groove width of the grid line grooves 110 is located, so that after the paste is transferred onto the cell 200, the line width of the part of the grid line formed on the cell 200 in contact with the cell 200 is smaller than the size at the position where the maximum grid line width is located, thereby reducing the light-shielding area of the grid lines on the cell 200 while ensuring the electrical performance, and thus being beneficial to improving the photoelectric conversion efficiency of the cell 200.

[0040] It should be noted that in this embodiment, the grid line grooves 110 do not penetrate the transfer film body 100 in the thickness direction of the transfer film body 100, that is, all the grid line grooves 110 are sunken grooves. The transfer film body 100 extends along a plane formed perpendicular to the first direction X and the second direction Y. The shape of the transfer film body 100 can be a square or a rectangle. Taking the shape of the transfer film body 100 as a rectangle as an example, the first direction X can be the width direction of the rectangle, and the second direction Y can be the length direction of the rectangle. The grid line grooves 110 are arranged at intervals along the width direction of the transfer film body 100, and the grid line grooves 110 are arranged parallel to each other. The grid line grooves 110 extend along the length direction of the transfer film body 100.

[0041] Such asFigure 1 As shown, in one embodiment, a plurality of grid grooves 110 are arranged in an array on the first side surface to form multiple groups of grid grooves 110 arranged at intervals along the second direction Y on the first side surface. In this way, each group of grid grooves 110 includes a plurality of grid grooves 110 arranged at intervals along the first direction X, and each grid groove 110 extends along the second direction Y. In this way, a laser transfer film can transfer multiple photovoltaic cells 200 at the same time. That is, one group of grid grooves 110 can transfer one cell 200. With such a setting, the transfer efficiency of the cells 200 can be improved.

[0042] As Figure 2 shown, in one embodiment, the cross-sectional shape of the grid groove 110 is configured as a semicircle. It should be noted that the groove depth of the semicircular grid groove 110 should be greater than the radius of the grid groove 110 and less than the diameter of the grid groove 110. And setting the shape of the grid groove 110 as a semicircle has a simple structure and is convenient for processing. Of course, in other embodiments, the shape of the grid groove 110 can also be set as an inverted trapezoid. However, when setting the inverted trapezoid, the sizes of the upper base and the lower base need to be appropriately set to facilitate the shedding of the paste. Further, the inner diameter of the grid groove 110 is between 15-25um, and the groove width of the grid groove 110 is between 10-20um. For example, when the inner diameter of the grid groove 110 is 15um, the groove opening of the grid groove 110 can be set at 10um, 13um; when the inner diameter of the grid groove 110 is set at 20um, the groove opening of the grid groove 110 can be set at 13um, 15um, 19um, etc.

[0043] Referring to Figures 3 to 5 , an embodiment of the present invention further provides a photovoltaic transfer system. A photovoltaic transfer system includes a base, a support platform, a frame, a laser module 300 and a stripping blade 400. The support platform is movably arranged on the base, and the support platform is used to support the cell 200; the frame is slidably connected to the base and is located above the support platform. The frame is used to support the above-mentioned laser transfer film, and the frame can drive the laser transfer film to contact the cell 200; the laser module 300 is arranged on the base and is located above the frame. The laser emitted by the laser module 300 can irradiate on the laser transfer film; the stripping blade 400 is slidably connected to the frame, and the stripping blade 400 can press against the second side surface of the laser transfer film. The paste in the grid groove 110 is separated from the grid groove 110 under the action of the stripping blade 400 and transferred onto the cell 200.

[0044] In this embodiment, the base is used to support the frame, the support platform, the laser module 300, the stripping blade 400, the filling blade 500, etc. Among them, the support platform is used to support the battery cell 200. The support platform is movably arranged on the base so that the support platform can move relative to the base, and then drive the battery cell 200 to move relative to the base. The frame is arranged in a form of sliding connection with the base so that the frame can move in a direction close to or away from the support platform. When it is necessary to transfer the battery cell 200, the frame can be moved to make the laser transfer film contact with the battery cell 200 to transfer the paste in the grid groove 110.

[0045] As Figure 4 shown, the laser module 300 is used to emit laser light and irradiate the emitted laser light on the laser transfer film. When the laser sweeps across the grid groove 110 filled with paste, the organic matter in the paste volatilizes. The stripping blade 400 is slidably connected to the frame so that the stripping blade 400 can move relative to the frame. By pressing the stripping blade 400 against the second side of the photovoltaic cell transfer film, under the action of the stripping blade 400, the photovoltaic cell transfer film is slightly deformed. Especially when the stripping blade 400 presses against the position corresponding to the grid groove 110, under the action of the stripping blade 400, the mouth of the grid groove 110 will open, so as to facilitate the paste to fall off from the grid groove 110.

[0046] In this embodiment, since the size of the slot opening of the grid groove 110 is smaller than the size of the widest part of the slot width of the grid groove 110, without external force, the paste is not easy to fall off. As Figure 5 shown, in this embodiment, by using the stripping blade 400 on the second side, the laser transfer film is deformed by the pressing of the stripping blade 400, so that the slot opening of the grid groove 110 opens to facilitate the paste to fall off. In addition, this embodiment adopts a contact transfer method, which can effectively avoid the defects that the grid lines formed by laser transfer in the prior art are easy to bend and break. The contact transfer method can ensure the adhesion and straightness of the grid lines, thus ensuring the performance of the grid lines.

[0047] In one of the embodiments, first guide rails are arranged at both ends of the frame along the second direction Y, and both ends of the stripping blade 400 are respectively slidably connected to the first guide rails. The first guide rails extend along the first direction X. In this way, it is realized that the stripping blade 400 can move along the first direction X, so that when stripping, when the stripping blade 400 moves along the first direction X, the paste in the grid grooves 110 spaced along the first direction X is sequentially transferred onto the paper battery cell 200.

[0048] As Figure 3As shown, in one embodiment, the photovoltaic transfer system further includes a filling squeegee 500. The filling squeegee 500 is movably disposed on the frame and is located below the laser transfer film. When the filling squeegee 500 moves relative to the frame along the first direction X, the filling squeegee 500 can be pressed against the first side surface to fill the paste in the filling squeegee 500 into the grid line grooves 110. Specifically, the filling squeegee 500 is a closed internal circulation squeegee.

[0049] It can be understood that the laser transfer film is fixed on the frame, and the first side surface faces the support platform. By disposing the filling squeegee 500 below the laser transfer film, when filling the grid line grooves 110 in the laser transfer film with paste, the filling squeegee 500 can be pressed against the first side surface, thereby realizing filling the grid line grooves 110 on the first side surface. By movably connecting the filling squeegee 500 to the frame, the filling squeegee can move relative to the frame, so that when the filling squeegee 500 moves along the first direction X of the frame once, all the grid line grooves 110 on the laser transfer film can be filled with paste, thus improving the filling efficiency.

[0050] Since the grid line grooves 110 are arranged in the direction facing the battery cell 200 and the paste has a certain fluidity, the paste is likely to drop during the paste filling. To prevent the paste from dropping, in this embodiment, the filling squeegee 500 is a closed internal circulation squeegee, so that when filling the paste, even if the paste drops, it drops into the filling squeegee 500, which is convenient for reusing the paste. In addition, in this embodiment, the grid line grooves 110 adopt a closed-end groove type, which is also beneficial to restricting the dropping of the paste during the paste filling.

[0051] Specifically, second guide rails are arranged at both ends of the side of the frame facing the support platform along the second direction Y. The two ends of the filling squeegee 500 are respectively slidably connected to the two second guide rails, and the second guide rails extend along the first direction X. The filling squeegee 500 is movably connected to the frame through the second guide rails to enable the filling squeegee 500 to move relative to the frame along the first direction X, thereby realizing the filling of the paste.

[0052] An embodiment of the present invention further provides a solar cell. The solar cell includes a battery cell 200, and a plurality of grid lines are arranged on the battery cell 200. The grid lines are formed by transferring through the above laser transfer film; the plurality of grid lines are arranged at intervals along the first direction X, the grid lines extend along the second direction Y, and the line width of the position where the grid lines are in contact with the battery cell 200 is smaller than the size of the position where the line width of the grid lines is the largest.

[0053] In this embodiment, a groove type is adopted in which the gear at the notch of the grid groove 110 is smaller than the dimension at the widest part of the groove width of the grid groove 110. By using different deformations of the groove type, the line width and line type of the grid line are optimized, which is beneficial to reducing the risk of grid line detachment and also beneficial to improving the photoelectric conversion efficiency of the battery chip 200.

[0054] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0055] The above-described embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed. However, it should not be construed as a limitation of the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the utility model patent shall be subject to the appended claims.

Claims

1. A laser transfer film for laser transfer of grid lines on photovoltaic cells, characterized in that: The laser transfer film comprises: A transfer film body, the transfer film body comprising a first side surface and a second side surface arranged opposite to each other, the first side surface being provided with a plurality of grid line grooves arranged at intervals along a first direction, the grid line grooves extending along a second direction, and the grid line grooves being used for filling slurry; The slot size of the gate line slot is smaller than the size of the position where the slot width of the gate line slot is the largest, the first direction and the second direction are orthogonal, and the transfer film body extends along the first direction and the second direction.

2. The laser transfer film according to claim 1, characterized in that: A plurality of the gate line grooves are distributed in an array on the first side surface, so as to form a plurality of groups of the gate line grooves spaced apart along the second direction on the first side surface.

3. The laser transfer film according to claim 1, characterized in that: The cross-sectional shape of the gate line groove is configured as a semicircle.

4. The laser transfer film according to claim 3, characterized in that: The inner diameter of the gate line groove is between 15-25 um, and the groove width of the gate line groove is between 10-20 um.

5. A photovoltaic transfer system, characterized in that: The photovoltaic transfer system comprises: Pedestal; A supporting platform, movably disposed on the base, and used for supporting the battery sheet; A frame, slidably connected to the base and located above the supporting platform, the frame is used to support the laser transfer film according to any one of claims 1 to 4, and the frame can drive the laser transfer film to contact the battery cell; A laser module is disposed on the base and located above the frame, and the laser emitted by the laser module can irradiate the laser transfer film; A stripping scraper is slidably connected to the frame. The stripping scraper can be pressed against the second side of the laser transfer film. The slurry in the grid line groove is separated from the grid line groove and transferred to the battery cell under the action of the stripping scraper.

6. The photovoltaic transfer system according to claim 5, characterized in that: The frame is provided with first guide rails at both ends along the second direction, and both ends of the stripping scraper are respectively slidably connected to the first guide rails, and the first guide rails extend along the first direction.

7. The photovoltaic transfer system according to claim 5, characterized in that: The photovoltaic transfer system also includes: A filling scraper, wherein the filling scraper is movably disposed on the frame and is located below the laser transfer film. When the filling scraper moves relative to the frame along the first direction, the filling scraper can be pressed against the first side surface to fill the slurry in the filling scraper into the gate line groove.

8. The photovoltaic transfer system according to claim 7, characterized in that: The filler scraper is a closed internal circulation scraper.

9. The photovoltaic transfer system according to claim 7, characterized in that: Second guide rails are provided at both ends of the frame facing the support platform along the second direction, and both ends of the filler scraper are respectively slidably connected to the two second guide rails, and the second guide rails extend along the first direction.

10. A solar cell, characterized in that: The solar cell comprises: A battery cell, wherein a plurality of gate lines are arranged on the battery cell, wherein the gate lines are formed by transfer from the laser transfer film as described in any one of claims 1 to 4; the plurality of gate lines are arranged at intervals along the first direction, the gate lines extend along the second direction, and the line width of the position where the gate lines contact the battery cell is smaller than the size of the position where the line width of the gate lines is the largest.

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