Film covering method of main-grid-free battery piece and processing tool of carrier film

Abstract

The invention discloses a film covering method of a main-grid-free battery piece and a processing tool of a carrier film. The film covering method comprises the following steps: cutting the carrier film to form a strip-shaped carrier film with a set width; extruding the strip-shaped carrier film in the length direction of the strip-shaped carrier film to form a strip-shaped groove; laying a plurality of welding strips on the surface of the main-grid-free battery piece; a strip-shaped carrier film is laid on each welding strip, and each welding strip is at least partially contained in a strip-shaped groove in the corresponding strip-shaped carrier film; and heating each strip-shaped carrier film, so that each welding strip is pre-fixed on the surface of the main-grid-free battery piece through the strip-shaped carrier film. According to the invention, the strip-shaped carrier film is extruded and processed to form the strip-shaped groove, so that the strip-shaped carrier film can wrap the surface of the welding strip more tightly, the gap between the welding strip and the battery piece is filled to the greatest extent, and the size of the contact surface between the strip-shaped carrier film and the battery piece can be increased; and the covering film fixing effect of the strip-shaped carrier film on the welding strip is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic products, in particular to a film coating method of a main-grid-free cell and a processing tool of a carrier film. BACKGROUND

[0002] In order to reduce the cost and increase the efficiency of photovoltaic cells, the photovoltaic cell gradually develops from a small number of main grids to multiple main grids, and then to a main-grid-free cell. The main-grid-free cell is a photovoltaic cell with only fine grid lines on the front surface of the photovoltaic cell. The main-grid-free cell needs to be welded with a solder strip to realize the current confluence of each main-grid-free cell and the series-parallel connection between multiple main-grid-free cells. Since there is no main grid line on the front surface of the main-grid-free cell, the solder strip can only be connected with the fine grid lines on the main-grid-free cell, and further fixedly connected with the cell by coating a film on the main-grid-free cell.

[0003] In the traditional film coating process, a film with a size similar to that of the front surface of the main-grid-free cell is generally used to cover the front surface of the cell. The strip-shaped film coating process is a new type of film coating process, that is, the carrier film is processed into a long strip-shaped structure, and the long strip-shaped carrier film is arranged on the area of the cell where the solder strip is arranged along the length direction of the solder strip. The strip-shaped film coating process can greatly reduce the material cost of the carrier film. However, how to improve the film coating and reinforcing effect of the long strip-shaped carrier film on the solder strip on the cell is still one of the technical problems to be studied in the industry. SUMMARY

[0004] The purpose of the present application is to provide a film coating method of a main-grid-free cell and a processing tool of a carrier film, which can improve the film coating and reinforcing effect of the strip-shaped carrier film on the solder strip on the cell.

[0005] To solve the above technical problems, the present application provides a film coating method of a main-grid-free cell, comprising:

[0006] cutting the carrier film to form a strip-shaped carrier film with a set width;

[0007] extruding the strip-shaped carrier film to form a strip-shaped groove along the length direction of the strip-shaped carrier film;

[0008] laying a plurality of solder strips on the surface of the main-grid-free cell;

[0009] applying a strip-shaped carrier film on each solder strip, and allowing each solder strip to be at least partially accommodated in the strip-shaped groove on the corresponding strip-shaped carrier film;

[0010] Each of the strip-shaped carrier films is heated so that each of the solder strips is pre-fixed on the surface of the busbar-free cell piece through the strip-shaped carrier film.

[0011] In an alternative embodiment of the present application, the strip-shaped carrier film is extruded to form a strip-shaped groove on the center line of the strip-shaped carrier film along the length direction of the strip-shaped carrier film, comprising:

[0012] The strip-shaped carrier films are arranged in parallel on a bearing platform.

[0013] A relative movement between an extruding member located above the bearing platform and the bearing platform is controlled so that the extruding member extrudes the strip-shaped carrier films on the bearing platform to form the strip-shaped groove.

[0014] In an alternative embodiment of the present application, the strip-shaped carrier film is extruded to form a strip-shaped groove on the center line of the strip-shaped carrier film, comprising:

[0015] The first surface of the strip-shaped carrier film is kept as a plane, a strip-shaped groove is extruded on the center area on the second surface of the strip-shaped carrier film, and two plane areas inclined to the first surface are extruded on the two side areas of the second plane so that the thickness of the strip-shaped carrier film gradually decreases from the notch edge of the strip-shaped groove to the two side edges of the strip-shaped carrier film.

[0016] In an alternative embodiment of the present application, the strip-shaped carrier film is extruded to form a strip-shaped groove on the center line of the strip-shaped carrier film, comprising:

[0017] The strip-shaped groove with a notch edge of a pointed protrusion is extruded on the center area on the second surface of the strip-shaped carrier film, and the pointed protrusion protrudes from the two plane areas on the two sides of the second plane, and the side surface of the pointed protrusion close to one side of the strip-shaped groove is flush with the groove wall of the strip-shaped groove, and the included angle between the side surface of the pointed protrusion away from the side of the strip-shaped groove and the plane area is obtuse.

[0018] In an alternative embodiment of the present application, the set width is not less than twice the cross-sectional perimeter of the solder strip.

[0019] The length of the cross-sectional profile of the strip-shaped groove is not less than three quarters of the cross-sectional perimeter of the solder strip.

[0020] In an alternative embodiment of the present application, the cross section of the strip-shaped groove is a U-shaped cross section.

[0021] A processing tool for a carrier film, used in the coating method for a gridless solar cell as described in any of the preceding claims, to extrude a strip-shaped carrier film to form a strip-shaped groove; the processing tool includes a support platform for supporting the strip-shaped carrier film, an extruder disposed above the support platform, and a drive assembly;

[0022] The extruder is used to extrude a strip-shaped groove along the length of the strip carrier film and on the center line of the strip carrier film when the strip carrier film is laid flat on the support platform and the drive assembly drives the extruder and the support platform to move relative to each other.

[0023] In one optional embodiment of this application, the extrusion member includes a plurality of rollers coaxially arranged; a convex ring is provided on the center line of the wheel surface of each roller;

[0024] The roller's shaft and the upper surface of the bearing platform are parallel to each other, and the gap between the convex ring on the roller and the upper surface of the bearing platform is less than the thickness of the strip carrier film.

[0025] The drive assembly is used to drive the roller and the support platform to move relative to each other along a direction perpendicular to the axis of rotation of the roller.

[0026] In one optional embodiment of this application, the wheel surfaces on both sides of the convex ring on the roller are two symmetrical conical wheel surfaces, and the diameter of the conical wheel surface closer to the convex ring is smaller than the diameter of the side away from the convex ring.

[0027] In an optional embodiment of this application, the roller has a V-shaped groove with a V-shaped cross-section between the wheel surface on both sides of the convex ring and the convex ring; and the groove wall on the side of the V-shaped groove away from the convex ring forms an obtuse angle with the wheel surface on both sides of the convex ring.

[0028] The present invention provides a coating method for a gridless solar cell and a processing tool for the carrier film. The coating method includes: cutting the carrier film to form a strip carrier film with a set width; extruding the strip carrier film along its length to form a strip groove; laying a plurality of solder strips on the surface of the gridless solar cell; applying a strip carrier film to each solder strip, such that each solder strip is at least partially accommodated in the strip groove on the corresponding strip carrier film; and heating each strip carrier film to pre-fix each solder strip to the surface of the gridless solar cell through the strip carrier film.

[0029] In this application, before coating the strip-shaped carrier film on the front side of the solar cell, a strip-shaped groove is formed on the strip-shaped carrier film by extrusion. The strip-shaped carrier film is then covered onto the solder ribbon on the gridless solar cell. Because the strip-shaped carrier film has a strip-shaped groove, when the strip-shaped carrier film is covered onto the solder ribbon, the solder ribbon can be inserted into the strip-shaped groove of the strip-shaped carrier film, so that the strip-shaped carrier film can more tightly wrap the surface of the solder ribbon, thereby effectively preventing the solder ribbon from shifting and deforming on the surface of the solar cell; and filling the gap between the solder ribbon and the solar cell to the greatest extent, which can increase the contact area between the strip-shaped carrier film and the solar cell, thereby increasing the adhesion between the strip-shaped carrier film and the solar cell. This largely ensures the coating and fixing effect of the strip-shaped carrier film on the solder ribbon, that is, ensures the low power attenuation of the photovoltaic solar cell coated by the coating method of this application in the actual power generation process. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0031] Figure 1 A schematic diagram of the cross-section of a conventional strip-shaped carrier film coating on the solder strip of a gridless solar cell;

[0032] Figure 2 A schematic flowchart illustrating the coating method for a grid-less solar cell provided in this application embodiment;

[0033] Figure 3 A schematic diagram of the structure of a strip-shaped carrier membrane with strip-shaped grooves provided in an embodiment of this application;

[0034] Figure 4 This is a schematic diagram of the structure for forming strip-shaped grooves by extruding a strip-shaped carrier film according to an embodiment of this application;

[0035] Figure 5 This is a schematic diagram of a coating process for a strip-shaped carrier membrane provided in an embodiment of this application;

[0036] Figure 6 This is a schematic diagram of the completed structure of the strip carrier membrane provided in the embodiments of this application;

[0037] Figure 7 A schematic diagram of another coating process for the strip carrier membrane provided in the embodiments of this application;

[0038] Figure 8This is a schematic diagram of a single roller in a machining tool provided in an embodiment of this application;

[0039] Figure 9 This is another structural schematic diagram of a single roller in the processing tool provided in the embodiments of this application. Detailed Implementation

[0040] like Figure 1 As shown, Figure 1 This is a schematic diagram of a cross-section of a conventional strip-shaped carrier film coated on the solder strip of a gridless solar cell. Obviously, when both surfaces of the strip-shaped carrier film 13 are planar, even if the two sides of the strip-shaped carrier film 13 extend obliquely downwards and adhere to the surface of the gridless solar cell 11 due to gravity, a roughly triangular gap will still be formed between the two sides of the strip-shaped carrier film 13 and the solder strip 12 and between the gridless solar cell 11. The contact area between the outer surfaces of the strip-shaped carrier film 13 and the solder strip 12 is insufficient, which weakens the fixing strength of the strip-shaped carrier film 13 to the solder strip 12, and the mutual adhesion between the strip-shaped carrier film 13 and the gridless solar cell 11 is also relatively insufficient.

[0041] To address this, this application provides a coating method for gridless solar cells. First, a strip-shaped groove is formed on a strip-shaped carrier film. Then, a solder strip is inserted into the groove to cover the strip-shaped carrier film on the solder strip. This allows the strip-shaped carrier film to more fully fill the gap between the solder strip and the gridless solar cell, increasing the contact area between them and improving the adhesion between them. This effectively ensures a good coating effect for the strip-shaped carrier film. Furthermore, this application provides a processing tool capable of creating the strip-shaped groove on the strip-shaped carrier film. This tool is simple in structure and easy to operate.

[0042] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. 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.

[0043] like Figures 2 to 4 As shown, Figure 2 A schematic flowchart illustrating the coating method for a grid-less solar cell provided in this application embodiment; Figure 3 A schematic diagram of the structure of a strip-shaped carrier membrane with strip-shaped grooves provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a strip-shaped carrier film extruded to form a strip-shaped groove, as provided in an embodiment of this application.

[0044] In one specific embodiment of this application, the coating method for the gridless solar cell may include:

[0045] S1: Cut the carrier membrane to form a strip carrier membrane with a set width;

[0046] S2: Extrude the strip-shaped carrier membrane along its length to form a strip-shaped groove;

[0047] S3: Lay several welding strips on the surface of the gridless solar cell;

[0048] S4: A strip carrier film is laid on each welding strip, such that each welding strip is at least partially contained in the strip groove on the corresponding strip carrier film;

[0049] S5: Heat each strip carrier film so that each welding strip is pre-fixed to the surface of the gridless cell through the strip carrier film.

[0050] In S1 of this embodiment, when cutting to form the strip-shaped carrier film 13, a carrier film with a planar structure can be used for strip cutting, thereby obtaining multiple straight strip-shaped carrier films 13. Obviously, when the strip-shaped carrier film 13 covers the solder ribbon 12 of the gridless solar cell 11, the length direction of the strip-shaped carrier film 13 should be parallel to the length direction of the solder ribbon 12. Therefore, the set width of the strip-shaped carrier film 13 should be based on the perimeter of the solder ribbon 12, and it should be ensured that the two sides of the strip-shaped carrier film 13 have a sufficiently large area to adhere to and cover the surface of the gridless solar cell 11. For example, the set width of the cut strip-shaped carrier film 13 can be no less than twice the perimeter of the solder ribbon 12.

[0051] After obtaining the strip-shaped carrier film 13 through S1, a strip-shaped groove 130 can be further formed by pressing one of the two surfaces of the strip-shaped carrier film 13, such as... Figure 2 As shown, the strip groove 130 formed by extrusion processing on the strip carrier film 13 should extend along the length direction of the strip carrier film 13, and the strip groove 130 is also symmetrical about the center line of the length direction of the strip carrier film 13.

[0052] In an optional embodiment of this invention, the process of extruding the strip-shaped groove 130 onto the strip-shaped carrier film 13 may include:

[0053] S21: Lay the strip-shaped carrier films parallel to each other on the support platform;

[0054] S22: Control the relative movement between the extruder located above the carrier platform and the carrier platform, so that the extruder extrudes the strip carrier film on the carrier platform to form a strip groove.

[0055] likeFigure 4 and Figure 8 As shown, in Figure 4 and Figure 8 In the illustrated embodiment, the extruder that presses the strip-shaped carrier film 13 consists of multiple coaxially arranged rollers 22. It is understood that each roller 22 should have a protruding ring 221 on its centerline. The cross-sectional shape of this protruding ring 221 should be the same as the cross-sectional shape of the strip-shaped groove 130 to be embossed. Therefore, after the strip-shaped carrier films 13 are laid flat on a flat support platform 21, as the support platform 21 moves, the strip-shaped carrier films 13 simultaneously pass under the rollers 22, and the protruding rings on each roller 22 simultaneously extrude and form strip-shaped grooves 130 on each strip-shaped carrier film 13. Alternatively, the support platform 21 can be mounted on a conveyor belt, with the conveyor belt moving in a direction parallel to the length direction of the strip-shaped carrier film 13. Thus, while keeping the rollers 22 stationary, the support platform 21 and the strip-shaped carrier films 13 can be simultaneously conveyed to the area under the rollers 22 via the conveyor belt.

[0056] However, it is understandable that when extruding the strip-shaped carrier film 13 to form the strip-shaped groove 130, the extruder is not limited to... Figure 4 The roller 22 shown, for example, the extruder can also be a pressure plate with straight ridges on its lower surface. By pressing the pressure plate against each strip-shaped carrier film 13 on the carrier platform 21, a strip-shaped carrier film 13 with strip grooves 130 can be obtained. In addition, in another optional embodiment of this application, the ridges can also be provided on the upper surface of the carrier platform 21, while the pressure plate does not have the ridges. The strip-shaped carrier film mold 13 is covered and placed on each ridge, and then the strip-shaped carrier film 13 on the carrier platform 21 is pressed by the pressure plate, so that the strip-shaped carrier film 13 adheres to the surface of the ridges on the carrier platform 21 to form strip grooves 130, thereby obtaining a strip-shaped carrier film 13 with strip grooves 130.

[0057] Based on the above discussion, in practical applications, various extrusion parts of different shapes and the carrier platform 21 can work together to achieve the processing and forming of the strip carrier film 13 with strip grooves 130. These are not listed one by one in this application.

[0058] It is understood that in this embodiment, the process of cutting the strip carrier film 13 before extruding it to form the strip grooves 130 before coating the strip carrier film 13 onto the solder strip 12 on the gridless solar cell 11 is merely one implementation of obtaining the strip carrier film 13 with strip grooves 130 in this application. In practical applications, this application does not exclude the direct extrusion of several strip grooves 130 on the uncut carrier film, and then cutting the carrier film based on the position of each strip groove 130 to form the strip carrier film 13, so that each strip carrier film 13 has a corresponding strip groove 130; in addition, the processes of cutting the strip carrier film 13 and extruding the strip grooves 130 in this application can be carried out simultaneously. For example, a processing tool with cutting blades on both sides and an extrusion component in the middle for extruding the carrier film to form strip grooves 130 can be used. By reasonably considering the relative positions between the cutting blades and the extrusion component, the cutting blades and the extrusion component can process the carrier film simultaneously, thereby forming the strip carrier film 13 with strip grooves 130 in one go. Therefore, it is evident that there is no sequential order between the steps of cutting to form the strip-shaped carrier film 13 and extruding to form the strip-shaped groove 130 in this application, as long as the final result can be formed as shown above. Figure 3 The strip carrier membrane 13 shown can be a strip carrier membrane 13 with strip grooves 130 on its surface.

[0059] After forming the strip-shaped carrier film 13 with the strip groove 130, the strip-shaped carrier film 13 can be further coated onto the solder ribbon 12 of the gridless solar cell 11. When coating the strip-shaped carrier film 13, the surface of the strip-shaped carrier film 13 with the strip groove 130 should be flipped downwards so that the strip groove 130 faces the solder ribbon 12. The strip-shaped carrier film 13 coats the solder ribbon 12 by inserting the solder ribbon 12 into the strip groove 130. Because the strip groove 130 is formed by extrusion on the strip-shaped carrier film 13 in this application, after the solder ribbon 12 is inserted into the strip groove 130, the groove wall of the strip groove 130 can better wrap the surface of the solder ribbon 12, thereby better filling the gap between the surface of the solder ribbon 12 and the surface of the gridless solar cell 11. This improves the fixing effect of the strip-shaped carrier film 13 on the solder ribbon 12 to a certain extent and increases the adhesion between the strip-shaped carrier film 13 and the surface of the gridless solar cell 11.

[0060] Based on this, to ensure the wrapping effect of the strip carrier film 13 on the welding strip 12, the cross-section of the strip groove 130 can be a U-shaped cross-section. For example, the bottom of the strip groove 130 can be a partially cylindrical groove bottom with a diameter greater than or equal to the diameter of the welding strip 12, or it can be a curved cylindrical groove bottom with a radius greater than the radius of the welding strip 12. No specific restrictions are placed on this in this application. Furthermore, to ensure that the welding strip 12 can be inserted into the strip groove 30, the width of the groove opening of the strip groove 130 should be greater than or equal to the diameter of the welding strip 12.

[0061] Based on the above discussion, in order to further improve the coating effect of the strip carrier membrane, refer to Figure 5 In an optional embodiment of this application, the process of forming the strip groove 130 on the strip carrier film 13 may further include:

[0062] The first surface 131 of the strip carrier film 13 is kept flat. A strip groove 130 is formed by pressing the central region on the second surface 132 of the strip carrier film 13. The two sides of the second flat surface 132 are pressed to form two planar regions 1321 that are inclined relative to the first surface 131, so that the thickness of the strip carrier film 13 gradually decreases from the groove edge of the strip groove 130 to the two sides of the strip carrier film 13.

[0063] exist Figure 5 In the illustrated embodiment, the strip groove 130 is located on the second surface 1321 of the strip carrier film 13. When the second surface 132 of the strip carrier film 13 faces downwards and is coated onto the solder ribbon 12, the outline of the second surface 132 in the cross-section of the strip carrier film 13 is approximately W-shaped. The thickness is greatest at the edge of the groove 130 on the entire strip carrier film 13, and the junction of the planar region 1321 and the groove opening can form a groove edge with a pointed structure. (Refer to...) Figure 4 When the strip carrier film 13 is coated onto the solder ribbon 12, the coating press applies a downward pressure force to the first surface 131 of the strip carrier film 13. This causes two planar regions 1321 on the second surface 132 of the strip carrier film 13 to be squeezed and adhered to the surface of the gridless solar cell 11. Since these two planar regions 1321 are inclined planes, they will obviously rotate at a certain angle towards the side closer to the solder ribbon 12. This rotation can cause the tip structure at the edge of the slot to move along... Figure 5 The direction indicated by the middle arrow extends downwards from the solder strip 12, thereby fully filling the gap between the solder strip 12 and the gridless solar cell 11, as shown in the image. Figure 6 As shown, using Figure 5 The strip-shaped carrier membrane 13 shown can achieve the following: Figure 6 The method shown completely wraps the entire outer surface of the solder ribbon 12, thereby achieving a secure connection between the solder ribbon 12 and the gridless solar cell 11, ensuring the tightness of their connection.

[0064] Of course, in practical applications, this application is not limited to the following. Figure 5 The strip-shaped carrier membrane 13 shown is structurally similar. Figure 6 As shown, in another optional embodiment of this application, the process of forming the strip groove 130 on the strip carrier film 13 may further include:

[0065] A strip groove 130 with a pointed protrusion is pressed into the central region of the second surface 132 of the strip carrier film 13. The pointed protrusion 133 protrudes from the planar regions 1321 on both sides of the second plane 132. The side of the pointed protrusion 133 near the strip groove 130 is flush with the groove wall of the strip groove 130, and the angle between the side of the pointed protrusion 133 away from the strip groove 130 and the planar region 1321 is an obtuse angle.

[0066] like Figure 7 As shown, in Figure 7 In the illustrated embodiment, the planar regions located on both sides of the strip-shaped groove 130 on the second surface 132 of the strip-shaped carrier film 13 are parallel to each other with respect to the first surface 131 of the strip-shaped carrier film 13. Based on this, a pointed protrusion 133 protruding from the planar region on the second surface 132 is formed only at the groove edge of the strip-shaped groove 130. Figure 5 The structure of the strip-shaped carrier membrane 13 shown is similar, with the thickness being greatest at the edge of the groove 130. When... Figure 7 When the strip-shaped carrier film 13 is coated onto the solder ribbon 12, after the solder ribbon 12 is inserted into the strip groove 130, because the side of the pointed protrusion 133 near the planar region 130 forms an obtuse angle with the planar region 132, as the coating press applies downward pressure to the first surface 131 of the strip-shaped carrier film 13 during the coating process, the side of the pointed protrusion 133 near the planar region 1321 in the strip-shaped carrier film 13 will gradually adhere to the surface of the gridless solar cell 11. This causes the tip of the pointed protrusion 133 to deflect towards the solder ribbon 12, and then extend to fill the gap between the bottom of the solder ribbon 12 and the surface of the gridless solar cell 11, thus achieving the same effect. Figure 6 The strip-shaped carrier film 13 shown wraps around the welding ribbon 12.

[0067] It should be noted that, in practical applications, in this embodiment, the angle between the side of the tip protrusion 133 near the planar region 1321 and the planar region 1321 can be appropriately larger, which can be greater than 135 degrees, for example, 165 degrees; thereby avoiding the formation of gap cavities due to the boundary area between the tip protrusion 133 and the planar region 1321 failing to adhere to the surface of the gridless solar cell 11 when the strip carrier film 13 is coated on the gridless solar cell 11.

[0068] Based on this, Figure 6The side of the pointed protrusion 133 near the groove 130 is part of the groove wall of the groove 130. In practical applications, the side of the pointed protrusion 133 near the groove 130 can also be slightly deflected towards the groove 130 with a small included angle, as long as the width between the tips of the pointed protrusions 133 on both sides of the groove 130 is greater than the diameter of the welding strip 12.

[0069] also Figure 7 The pointed protrusion shown protrudes from the planar region of the second surface 132 of the strip-shaped carrier film 13, relative to Figure 5 Regarding the tip structure formed by the planar region 1321 of the second surface 132 of the strip-shaped carrier film 13 and the groove wall of the strip-shaped groove 130, Figure 6 The included angle of the tip of the central tip protrusion 133 can be smaller, thus enabling it to extend better into the gap between the gridless cell 11 and the solder strip 12.

[0070] In addition, in this embodiment, the first surface 131 of the strip-shaped carrier film 13 can also be a plane, and the planar region on the second surface 132 can also be similar to... Figure 5 The part shown is inclined relative to the first surface 131.

[0071] It is understandable that in practical applications, the strip-shaped carrier film 13 in this application can be extruded to form more different surface structures, as long as it can ensure that the strip-shaped carrier film 13 can wrap the surface of the solder ribbon 12 as much as possible, so that the gap between the solder ribbon 12 and the gridless cell 11 is filled. These are not listed one by one in this application.

[0072] In summary, before applying the strip-shaped carrier film to the front of the solar cell, the strip-shaped carrier film is extruded to form strip grooves. These grooves are then applied to the solder ribbon on the gridless solar cell. Because the strip-shaped carrier film has these grooves, it can accommodate the solder ribbon within them, allowing the carrier film to more tightly wrap the ribbon surface. This effectively prevents the ribbon from shifting or deforming on the solar cell surface and maximizes the filling of the gap between the ribbon and the solar cell. This increases the contact area between the carrier film and the solar cell, thereby increasing their adhesion. This significantly ensures the effective fixation of the ribbon by the carrier film, thus guaranteeing low power attenuation during actual power generation for photovoltaic cells coated using the method described in this application.

[0073] Based on any of the above embodiments, this application also provides an embodiment of a carrier membrane processing tool. It is understood that the carrier membrane processing tool in this embodiment is also the tool for processing and forming the strip carrier membrane 13 with the strip groove 130 in any of the above embodiments.

[0074] like Figure 4 As shown, in one specific embodiment of this application, the processing tool for the carrier membrane may include:

[0075] A support platform 21 for carrying the strip carrier film 113, an extruder disposed above the support platform 21, and a drive assembly;

[0076] The extruder is used to extrude the strip carrier film 13 along the length direction of the strip carrier film 13 to form a strip groove 130 on the center line of the strip carrier film 13 when the strip carrier film 13 is laid flat on the carrier platform 21 and the drive assembly drives the extruder and the carrier platform 21 to move relative to each other.

[0077] It is understood that one of the components of the processing tool extruder and the carrier platform 21 in this embodiment should have a surface shape corresponding to the strip groove 130. Thus, when the extruder is driven to move relative to the carrier platform by the driving component, so that the extruder and the carrier platform 21 cooperate to apply a squeezing force to the strip carrier film 13, the surface shape structure corresponding to the extruder and the carrier platform 21 can form the required strip groove 130 on the surface of the strip carrier film 13.

[0078] In this embodiment, the support platform 21 can generally be a flat plate structure, and each strip-shaped carrier film 13 can be laid flat on its upper surface. The corresponding extruder can have various different implementations, and the way the drive assembly drives the extruder and the support platform 21 to move relative to each other varies depending on the extruder. For example, the extruder can be a pressure plate, with a straight protrusion on the lower surface of the pressure plate. The cross-section of the straight protrusion is the same as the cross-section of the strip groove 130 to be formed. When the drive assembly drives the pressure plate to press down on each strip-shaped carrier film 13 above the support platform 21, and each protrusion is aligned with the center line of a strip-shaped carrier film 13, a strip groove 130 can be formed on the surface of the strip-shaped carrier film 13 away from the support platform 21. Of course, the lower surface of each pressure plate can also be a plane, and the support platform 21 can be provided with protrusions. Similarly, the pressure plate and the support platform 21 can be used together to extrude the strips to form a strip groove 130 on the strip-shaped carrier film 13.

[0079] Reference Figure 4 and Figure 8 As shown, in an optional embodiment of this application, the extruder may include:

[0080] Multiple rollers 22 are coaxially arranged; each roller 22 has a convex ring 221 on the center line of its wheel surface;

[0081] The shaft of the roller 22 and the upper surface of the bearing platform 21 are parallel to each other, and the gap between the convex ring 221 on the roller 22 and the upper surface of the bearing platform 22 is smaller than the thickness of the strip carrier film 13.

[0082] The drive assembly is used to drive the roller 33 and the support platform 21 to move relative to each other along a direction perpendicular to the axis of rotation of the roller 22.

[0083] like Figure 4 As shown, in this embodiment, each roller 22 can be arranged on the same rotating shaft, so that each roller 22 can rotate synchronously around the straight line where the rotating shaft is located as the rotation center; on this basis, the driving component can be a conveyor belt that can drive the carrying platform 21 to move, or other driving devices that can drive the carrying platform 21 to move past each roller 22.

[0084] In addition, the carrier platform 21 in this embodiment can also remain fixed, while the rollers are driven by the driving device to roll synchronously on the carrier platform 21, thereby passing through the positions of the strip carrier films 13 on the carrier platform 21, and extruding the strip carrier films 13, or extruding them to form strip grooves 130.

[0085] like Figure 8 As shown, in an optional embodiment of this application, the processing tool may further include:

[0086] The wheel surfaces on both sides of the convex ring 221 on the roller 22 are two symmetrical conical wheel surfaces 222, and the diameter of the conical wheel surface 222 on the side closer to the convex ring 221 is smaller than the diameter on the side away from the convex ring 221.

[0087] In this embodiment, the upper surface of the support platform 21 supporting the strip carrier film 13 is flat, thus the strip carrier film 13 does not conform to the surface shape of the support platform 21. Furthermore, the wheel surfaces on the rollers 22 located on both sides of the convex ring 221 are conical wheel surfaces 222. Therefore, when each roller 22 rolls the strip carrier film 13 along its length, it can be processed into the shape shown below. Figure 5 The strip groove 130 shown is illustrated.

[0088] like Figure 9 As shown, in an optional embodiment of this application, the processing tool may further include:

[0089] The roller 22 has a V-shaped groove 224 with a V-shaped cross-section between the flat wheel surface 223 on both sides of the convex ring 221 and the convex ring 221; and the groove wall on the side of the V-shaped groove away from the convex ring and the flat wheel surface 223 on both sides of the convex ring 221 form an obtuse angle.

[0090] based on Figure 9 After the roller 22 shown extrudes the strip carrier film 13 on the support platform, the V-shaped annular groove 224 can make the groove edge of the strip groove 130 form as shown. Figure 7 The tip protrusion 133 shown.

[0091] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, 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 said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0092] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A coating method for gridless solar cells, characterized in that, include: The carrier membrane is cut to form strips of a set width; The strip-shaped carrier membrane is extruded along its length to form a strip-shaped groove; Several welding strips are laid on the surface of the gridless solar cell; A strip carrier film is applied to each of the welding strips, such that each welding strip is at least partially accommodated in a strip groove on the corresponding strip carrier film; Each of the strip-shaped carrier films is heated so that each of the welding ribbons is pre-fixed to the surface of the gridless solar cell through the strip-shaped carrier film.

2. The coating method for grid-less solar cells as described in claim 1, characterized in that, Along the length of the strip-shaped carrier membrane, a strip-shaped groove is formed by extruding the strip-shaped carrier membrane along its center line, including: Each of the strip-shaped carrier films is laid flat on the support platform, parallel to each other; The relative movement between the extruder located above the support platform and the support platform is controlled so that the extruder extrudes the strip-shaped carrier film on the support platform to form the strip-shaped groove.

3. The coating method for grid-less solar cells as described in claim 1, characterized in that, The strip-shaped carrier film is extruded along its centerline to form a strip-shaped groove, including: The first surface of the strip-shaped carrier film is kept flat. A strip-shaped groove is formed in the central region of the second surface of the strip-shaped carrier film. The two sides of the second flat surface are also formed into two planar regions that are inclined relative to the first surface, so that the thickness of the strip-shaped carrier film gradually decreases from the groove edge to the two sides of the strip-shaped carrier film.

4. The coating method for gridless solar cells as described in any one of claims 1 to 3, characterized in that, The strip-shaped carrier film is extruded along its centerline to form a strip-shaped groove, including: A strip-shaped groove with a pointed protrusion is pressed into the central region of the second surface of the strip-shaped carrier film. The pointed protrusion protrudes into the planar regions on both sides of the second plane. The side of the pointed protrusion closest to the strip-shaped groove is flush with the groove wall of the strip-shaped groove, and the angle between the side of the pointed protrusion away from the strip-shaped groove and the planar region is an obtuse angle.

5. The coating method for grid-less solar cells as described in claim 1, characterized in that, The set width is not less than twice the perimeter of the cross-section of the welding strip; Furthermore, the length of the cross-sectional outline of the groove is not less than three-quarters of the cross-sectional perimeter of the welding strip.

6. The coating method for grid-less solar cells as described in claim 1, characterized in that, The cross-section of the strip groove is U-shaped.

7. A processing tool for a carrier membrane, characterized in that, In the coating method for a gridless solar cell as described in any one of claims 1 to 6, a strip-shaped carrier film is extruded to form a strip-shaped groove; the processing tool includes a support platform for supporting the strip-shaped carrier film, an extruder disposed above the support platform, and a drive assembly; The extruder is used to extrude a strip-shaped groove along the length of the strip carrier film and on the center line of the strip carrier film when the strip carrier film is laid flat on the support platform and the drive assembly drives the extruder and the support platform to move relative to each other.

8. The processing tool for the carrier membrane as described in claim 7, characterized in that, The extrusion member includes a plurality of rollers arranged coaxially; a convex ring is provided on the center line of the wheel surface of each roller; The roller's shaft and the upper surface of the bearing platform are parallel to each other, and the gap between the convex ring on the roller and the upper surface of the bearing platform is less than the thickness of the strip carrier film. The drive assembly is used to drive the roller and the support platform to move relative to each other along a direction perpendicular to the axis of rotation of the roller.

9. The processing tool for the carrier membrane as described in claim 8, characterized in that, The roller has two symmetrical conical surfaces on both sides of the convex ring, and the diameter of the conical surface closer to the convex ring is smaller than the diameter of the side away from the convex ring.

10. The processing tool for the carrier membrane as described in claim 8, characterized in that, The roller has a V-shaped groove with a V-shaped cross-section between the wheel surface on both sides of the convex ring and the convex ring; and the groove wall on the side of the V-shaped groove away from the convex ring forms an obtuse angle with the wheel surface on both sides of the convex ring.

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