Method of manufacturing a photovoltaic module and photovoltaic module

Abstract

Embodiments of the present application relate to a photovoltaic module preparation method and a photovoltaic module. The preparation method comprises: providing a first cover plate, a first adhesive film and a cell structure stacked along a first direction, the cell structure comprising a plurality of back contact cells, each back contact cell comprising a positive grid line and a negative grid line away from the surface of the first cover plate; providing a second adhesive film, arranging a solder strip on the surface of the second adhesive film, and pre-fixing the solder strip and the second adhesive film; laying the second adhesive film on the surface of the cell structure away from the first cover plate, so that the solder strip contacts the positive grid line and the negative grid line on the adjacent back contact cells respectively, the positive grid line being located on one of the two adjacent back contact cells, and the negative grid line being located on the other; providing a second cover plate, and arranging the second cover plate on the surface of the second adhesive film away from the cell structure; and through laminating forming, the wrapping layer of the solder strip is melted and fixedly connected with the grid lines. At least it is conducive to improving the yield of the photovoltaic module and reducing the cost of the module.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a method for preparing a photovoltaic module and a photovoltaic module. Background Technology

[0002] Fossil fuels cause air pollution and have limited reserves, while solar energy has advantages such as being clean, pollution-free, and abundant. Therefore, solar energy is gradually becoming the core clean energy source to replace fossil fuels. Due to the excellent photoelectric conversion efficiency of solar cells, solar cells have become the focus of development for clean energy utilization.

[0003] Back-side contact (BC) cells have attracted increasing attention due to their superior photoelectric conversion performance. However, because both the positive and negative electrodes are located on the back of the cell, the welding stress generated by the front and back solder strips cannot be offset as in conventional cells when using BC cells to fabricate photovoltaic modules. Therefore, during the fabrication of back-side contact modules using BC cells, the cells are prone to warping under welding stress after welding, leading to problems such as microcracks or even breakage in subsequent processes. This results in lower yields and higher manufacturing costs for back-side contact modules. Summary of the Invention

[0004] This application provides a method for preparing a photovoltaic module and a photovoltaic module, which at least helps to improve the yield of photovoltaic modules and reduce the manufacturing cost of photovoltaic modules.

[0005] This application provides a method for manufacturing a photovoltaic module, comprising: providing a first cover plate, a first encapsulant film, and a battery structure stacked along a first direction, the battery structure including a plurality of back contact cells, each of the back contact cells having a positive grid line and a negative grid line on its surface away from the first cover plate; providing a second encapsulant film, on the surface of the second encapsulant film at least one solder strip having a conductive core and a wrapping layer covering the conductive core, pre-fixing the solder strip to the second encapsulant film; laying the second encapsulant film onto the surface of the battery structure away from the first cover plate, such that at least a portion of the solder strip contacts the positive grid line and the negative grid line on adjacent back contact cells respectively, and the positive grid line is located on one of two adjacent back contact cells, and the negative grid line is located on the other; providing a second cover plate and placing the second cover plate on the surface of the second encapsulant film away from the battery structure; and laminating the encapsulant film through a lamination process, such that the wrapping layer melts during the lamination process and forms a fixed connection with the positive grid line and / or the negative grid line.

[0006] In some embodiments, the step of setting the solder ribbon includes: laying the solder ribbon on the surface of the second adhesive film; heating the second adhesive film in the area where the solder ribbon is located to bond the solder ribbon to the second adhesive film, and the second adhesive film covering the solder ribbon to a plurality of portions of its thickness in a direction perpendicular to the surface of the second adhesive film.

[0007] In some embodiments, the ratio of the thickness of the portion of the solder ribbon covered by the second adhesive film to the thickness of the solder ribbon in a direction perpendicular to the surface of the second adhesive film is 0.2 to 0.5.

[0008] In some embodiments, the process parameters of the heat treatment include: a heating temperature of 65 degrees Celsius to 110 degrees Celsius, and / or a heating duration of 0.25 seconds to 1 second.

[0009] In some embodiments, the step of setting the solder ribbon includes: applying adhesive to a portion of the surface of the second adhesive film, and laying the solder ribbon on the surface of the second adhesive film where the adhesive is applied.

[0010] In some embodiments, the step of applying adhesive includes: forming a plurality of grooves on the surface of the second adhesive film; applying adhesive to at least a portion of the surface of the second adhesive film exposed by each of the grooves; and the method of laying the solder ribbon includes: laying the solder ribbon in the grooves coated with adhesive.

[0011] In some embodiments, the ratio between the groove depth and the thickness of the solder strip in a direction perpendicular to the surface of the second adhesive film is 0.1 to 0.5.

[0012] In some embodiments, after pre-fixing the solder strips and the second adhesive film, the method further includes: providing an insulating portion between at least partially adjacent solder strips, the insulating portion being spaced apart from the adjacent solder strips.

[0013] Corresponding embodiments of this application also provide a photovoltaic module, including: a first cover plate, a cell structure, and a second cover plate stacked along a first direction, and an encapsulation film located between the first cover plate and the second cover plate and covering the cell structure; the cell structure includes a plurality of back contact cells and a plurality of solder strips, each of the back contact cells having a positive grid line and a negative grid line on its surface facing the first cover plate, at least a portion of the solder strips contacting the positive grid line and the negative grid line on adjacent back contact cells respectively, and the positive grid line being located on one of two adjacent back contact cells, and the negative grid line being located on the other; along the first direction, the side of the solder strip away from the first cover plate includes a solder area, and the solder area is continuously arranged along the extension direction of the long side of the solder strip.

[0014] In some embodiments, the melting point of the solder strip is between 120 and 160 degrees Celsius.

[0015] In some embodiments, the solder strip includes a conductive core and a wrapping layer covering the conductive core, the wrapping layer having a melting point of 120 to 160 degrees Celsius.

[0016] The technical solution provided in this application has at least the following advantages:

[0017] The photovoltaic module manufacturing method provided in this application involves forming a first cover plate, a first encapsulant film, and a cell structure stacked together before lamination. Solder ribbons are pre-placed on the surface of the second encapsulant film facing the cell structure, and the solder ribbons and the second encapsulant film are pre-fixed. The second encapsulant film contacts the back side of the cell structure composed of back-contact cells. By laying the solder ribbons on the surface of the second encapsulant film and pre-fixing them, the solder ribbons in the formed photovoltaic module can be accurately positioned in specific locations, achieving electrical connection between adjacent cells in the cell structure. Then, the second encapsulant film with the solder ribbons placed is laid onto the surface of the cell structure, so that the solder ribbons contact the positive and negative grid lines on adjacent back-contact cells, respectively. The positive grid line is located on one of the two adjacent back-contact cells, and the negative grid line is located on the other. The module is then formed through a lamination process, causing the solder ribbon wrapping layer to melt during lamination and form a fixed connection with the grid lines of the back-contact cells. By melting the solder ribbon during the lamination process and fixing it to the grid lines of the back contact cell, the pressure during lamination and the fixing effect of the adhesive film on the cell are used to prevent the cell from warping under welding stress. This reduces the probability of microcracks or damage to the cells in the photovoltaic module, improves the yield of the photovoltaic module, and reduces the manufacturing cost. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments, and unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0019] Figure 1 This is a schematic diagram of the overall structure of a photovoltaic module provided in one embodiment of this application;

[0020] Figure 2 This is a top view of a battery structure provided in an embodiment of this application;

[0021] Figure 3 This is a schematic diagram of the overall structure of another photovoltaic module provided in an embodiment of this application;

[0022] Figure 4 A top view of a second adhesive film provided in an embodiment of this application;

[0023] Figure 5 This is a schematic cross-sectional view of a second adhesive film provided in an embodiment of this application;

[0024] Figure 6 This is a schematic cross-sectional view of another second adhesive film provided in an embodiment of this application;

[0025] Figure 7 This is a schematic cross-sectional view of another second adhesive film provided in an embodiment of this application;

[0026] Figure 8 This is a schematic diagram of the structure of a photovoltaic module before lamination, provided in one embodiment of this application;

[0027] Figure 9 This is a schematic diagram of the overall structure of another photovoltaic module provided in an embodiment of this application;

[0028] Figure 10 A cross-sectional structural schematic diagram of another second adhesive film provided in an embodiment of this application;

[0029] Figure 11 This is a cross-sectional structural diagram of another second adhesive film provided in an embodiment of this application. Detailed Implementation

[0030] As can be seen from the background technology, the current yield rate of photovoltaic modules needs to be improved, and the manufacturing cost is relatively high.

[0031] refer to Figure 1 , Figure 1 This is a schematic diagram of the overall structure of a photovoltaic module, where the X direction is the first direction. In some embodiments, the photovoltaic module includes a first cover plate 101, a battery structure 102, and a second cover plate 103 stacked sequentially along the first direction, and an encapsulation film 104 located between the first cover plate 101 and the second cover plate 103, covering the battery structure 102.

[0032] refer to Figure 2 , Figure 2 This is a top view of a battery structure 102. The battery structure 102 consists of multiple battery cells 120 and connecting components 121 that connect adjacent battery cells 120. Figure 2 A top view of two adjacent battery cells 120 connected to each other in battery structure 102 is shown.

[0033] The solar cell 120 includes cells with main grids and cells without main grids. When the solar cell 120 is a cell with main grids, its surface typically has multiple main grids arranged alternately along a second direction and multiple sub-grids perpendicular to the main grid arrangement direction. Main grids and sub-grids with the same polarity are electrically connected, while main grids and sub-grids with different polarities remain insulated from each other. When the solar cell 120 is a cell without main grids, its surface has multiple sub-grids arranged at intervals along a direction perpendicular to the second direction.

[0034] When the battery cell 120 is a cell with a main grid, during the formation of the battery structure 102, the battery cells 120 are first arranged on the worktable in a specific layout. Then, the connecting component 121 is placed above two adjacent battery cells 120, so that the connecting component 121 is directly opposite two main grids with different polarities, with one main grid located on one of the two adjacent battery cells 120 and the other main grid located on the other of the two adjacent battery cells 120. Then, the connecting component 121 is welded to the main grid to form an electrical connection between the connecting component 121 and the main grid, thereby connecting the two adjacent battery cells 120. By performing similar processing on multiple adjacent battery cells 120, the battery structure 102 is formed.

[0035] In the case where the solar cell 120 is a gridless cell, during the formation of the cell structure 102, after the solar cells 120 are arranged, the connecting component 121 is placed directly on top of two adjacent solar cells 120, so that the orthographic projection of the connecting component 121 on the solar cell 120 overlaps with the multiple sub-grid portions located on the two adjacent solar cells 120 respectively. Then, the connecting component 121 is electrically connected to the multiple sub-grids and connected to the two adjacent solar cells 120 by means of heating or other methods. By performing similar processing on multiple adjacent solar cells 120, the cell structure 102 is formed. The connecting component 121 includes solder ribbons or busbars, etc.

[0036] In addition, it is worth mentioning that when the battery cell 120 is a back-contact battery, the grid lines of the battery cell 120 are all located on the back side of the battery cell 120, and the connecting component 121 contacts the grid lines on the back side of two adjacent battery cells 120 respectively, thereby connecting the adjacent battery cells 120.

[0037] Then, a first cover plate 101, a second cover plate 103, and two layers of adhesive film constituting the encapsulation film 104 are provided. A layer of adhesive film is then laid on each of the two opposite surfaces of the battery structure 102. The first cover plate 101 and the second cover plate 103 are then placed on the surfaces of the adhesive films located on different sides of the battery structure 102, away from the battery structure 102, forming a laminated structure. Finally, the laminated structure is transferred to a laminating machine, where the two layers of adhesive film laid on the two opposite surfaces of the battery structure 102 are fused together through lamination to form the encapsulation film 104 covering the battery structure 102. The encapsulation film 104 then bonds the first cover plate 101 and the second cover plate 103 to the battery structure 102. The lamination process forms the encapsulation film 104 with excellent encapsulation effect, improving the reliability of the photovoltaic module.

[0038] One embodiment of this application provides a method for manufacturing photovoltaic modules, applied to photovoltaic module manufacturing equipment, including:

[0039] refer to Figure 3 , Figure 3 This is a schematic diagram of the overall structure of a photovoltaic module, where the X direction is the first direction. A first cover plate 201, a first encapsulant film 202, and a cell structure 203 are provided and stacked along the first direction. The cell structure 203 includes a plurality of back-contact cells 230, and the surface of each back-contact cell 230 away from the first cover plate 201 includes positive grid lines and negative grid lines.

[0040] In the process of manufacturing photovoltaic modules, the front structure of the photovoltaic module can be prepared first. First, the first cover plate 201 and the first encapsulant film 202 are laid. Then, multiple back contact cells 230 are laid on the surface of the first encapsulant film 202 away from the first cover plate 201. Each back contact cell 230 is arranged on the surface of the first encapsulant film 202 in a preset arrangement to form a cell structure 203.

[0041] The front structure refers to the structure of the photovoltaic module facing the light-receiving surface of the back contact cell 230. When the back contact cell 230 is illuminated from one side, the light-receiving surface refers to the surface of the back contact cell 230 that receives incident light. When the back contact cell 230 is illuminated from both sides, the light-receiving surface refers to the surface of the back contact cell 230 that receives the stronger incident light. By first setting and fabricating the front structure, the probability of damage to the light-receiving surface of the back contact cell 230 during lamination is reduced, thus improving the reliability of the photovoltaic module.

[0042] It is worth mentioning that the arrangement of the back contact batteries 230 in battery structure 203 is similar to the arrangement of the battery cells 120 in battery structure 102, but the interconnection of adjacent back contact batteries 230 in battery structure 203 is not yet realized. The back contact batteries 230 included in battery structure 203 are back contact batteries, and each back contact battery has multiple positive and negative grid lines on the surface away from the first cover plate 201.

[0043] In some embodiments, the back contact battery 230 may have a main grid electrode, a positive grid line including a positive sub-grid and a positive main grid, and a negative grid line including a negative main grid and a negative sub-grid. The positive sub-grid and negative sub-grid are arranged alternately along the sub-grid arrangement direction, and the positive main grid and negative main grid are arranged alternately along the main grid arrangement direction. The positive main grid is electrically connected to multiple positive sub-grids, and the negative main grid is electrically connected to multiple negative sub-grids. In subsequent processes, during the connection of adjacent back contact batteries 230, the connecting component is fixedly connected to the main grid on the back contact battery 230. The sub-grid arrangement direction and the main grid arrangement direction may be perpendicular to each other or have an angle of 60 degrees, 45 degrees, or 30 degrees, etc. The connecting component includes a solder strip or a busbar.

[0044] In some embodiments, the back contact battery 230 in the battery structure 203 can also be a gridless battery. When the back contact battery 230 in the battery structure 203 is a gridless battery, the arrangement of the back contact batteries 230 remains unchanged. The positive grid lines on the back of the back contact battery 230 are positive sub-grids, and the negative grid lines are negative sub-grids. The positive and negative sub-grids are arranged alternately along the sub-grid arrangement direction. In subsequent processes, during the connection of adjacent back contact batteries 230, the connecting component is fixedly connected to the sub-grids on the back contact battery 230. The connecting component communicates with multiple positive sub-grids on one of the adjacent back contact batteries 230 and with multiple negative sub-grids on the other. The connecting component includes solder strips or busbars.

[0045] In some embodiments, the back contact cell 230 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-element compound solar cell, etc. The back contact cell 230 can be a whole cell or a sliced ​​cell; a sliced ​​cell refers to a cell formed by cutting a complete whole cell.

[0046] In some embodiments, the first cover plate 201 needs to have high hardness and transparency. Transparency refers to the transmittance of the first cover plate 201 to light of a specific wavelength. Therefore, the first cover plate 201 can be a glass cover plate, a plastic cover plate, or other cover plate with good light transmission function and not easily damaged. Good light transmission function includes having a transmittance of more than 80% to light with a wavelength greater than 400nm or a transmittance of more than 85% to light with a wavelength greater than 450nm.

[0047] In some embodiments, the first adhesive film 202 serves to form an encapsulation film including a battery structure through a subsequent lamination process. The first adhesive film 202 is located between the first cover plate 201 and the light-receiving surface of the back contact battery 230. Therefore, the first adhesive film 202 needs to have good transparency. The first adhesive film 202 can be an ethylene-vinyl acetate copolymer (EVA) film, a polyolefin thermoplastic elastomer (POE) film, a polyethylene glycol terephthalate (PET) film, or a polyvinyl butyral film (PVB) film, etc.

[0048] The first film 202 can be a single-layer film or a multi-layer co-extruded film, such as EP film, EPE film, or PVP film. Specifically, EP film refers to a co-extruded film composed of stacked EVA and POE films; EPE film refers to a co-extruded film formed by sequentially stacking EVA film, POE film, and EVA film; and PVP film refers to a co-extruded film formed by stacking POE film, EVA film, and POE film. The co-extruded film can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0049] Reference Figure 1 , Figure 4 and Figure 5 A second adhesive film 204 is provided, and at least one solder ribbon 240 is disposed on the surface of the second adhesive film 204. The solder ribbon 240 includes a conductive core and a wrapping layer covering the conductive core, and the solder ribbon 240 is pre-fixed to the second adhesive film 204. Figure 4 This is a top view of the second adhesive film 204. Figure 5 This is a schematic cross-sectional view of the second adhesive film 204, wherein, Figure 4The central area A indicates the positional relationship between the back contact battery 230 and the solder strip 240. Figure 5 for Figure 4 The schematic diagram of the cross-sectional structure of the middle region B along the aa1 direction is shown. For ease of use, this embodiment of the application uses multiple solder strips 240 as an example for explanation. In specific applications, the number of solder strips 240 laid on the surface of the second adhesive film 204 can also be 1 or 2.

[0050] When providing a second adhesive film 204 covering the surface of the battery structure 203 away from the first cover plate 201, an untreated second adhesive film 204 can be provided. At least one solder ribbon 240 is then placed on the surface of the second adhesive film 204 and fixed to the second adhesive film 204 by pre-fixation. During the placement of the solder ribbon 240, it can be positioned according to the grid lines of each back contact battery 230 included in the battery structure 203. This ensures that after the second adhesive film 204 is laid on the surface of the battery structure 203 away from the first cover plate 201, the solder ribbon 240 can accurately connect adjacent back contact batteries 230 after subsequent processing. The solder ribbon 240 is a low-temperature solder ribbon, meaning it has a low melting point, for example, below 160 degrees Celsius or 180 degrees Celsius.

[0051] In addition, when providing the second encapsulant film 204, at least one solder ribbon 240 can be pre-laid and pre-fixed on the second encapsulant film 204, directly providing a finished second encapsulant film 204 that has undergone the solder ribbon laying and pre-fixing process, reducing the process of photovoltaic module manufacturing, reducing the difficulty of photovoltaic module manufacturing, and improving module manufacturing efficiency.

[0052] In addition, the material and structure of the second adhesive film 204 can be similar to those of the first adhesive film 202, so they will not be described in detail here.

[0053] In some embodiments, the step of setting the solder ribbon 240 includes: laying the solder ribbon 240 on the surface of the second adhesive film 204; heating the second adhesive film 204 in the area where the solder ribbon 240 is located to bond the solder ribbon 240 to the second adhesive film 204, and in a direction perpendicular to the surface of the second adhesive film 204, the second adhesive film 204 covers the solder ribbon 240 to a multiple thickness.

[0054] refer to Figure 6 , Figure 6This is a cross-sectional structural diagram of a second adhesive film 204. During the process of setting the solder ribbon 240 on the second adhesive film 204, the solder ribbon 240 can be first laid onto one surface of the second adhesive film 204, forming a second adhesive film 204 with the solder ribbon 240 on its surface. After laying the solder ribbon 240 onto the surface of the second adhesive film 204, the area of ​​the second adhesive film 204 where the solder ribbon 240 is located is heated. That is, the adhesive film in contact with the solder ribbon 240 and the adhesive film around the second adhesive film 204 in contact with the solder ribbon 240 are heated, causing the second adhesive film 204 to melt. The heated and flowing second adhesive film 204 covers the surface of the solder ribbon 240, and after cooling, an adhesive portion is formed that bonds the solder ribbon 240 to the second adhesive film 204, thus forming a bond between the solder ribbon 240 and the second adhesive film 204. Figure 5 The bonding state is shown. During the heat treatment of the second adhesive film 204, if the heating temperature is high or the heating time is long, the solder ribbon 240 may also melt to a certain extent, thereby forming an adhesive part formed by the mixture of the adhesive film and the solder ribbon 240 with the melted second adhesive film 204.

[0055] During the heat treatment process, the portion of the second adhesive film 204 in contact with the solder ribbon 240 melts. Since the melted second adhesive film 204 is fluid, the solder ribbon 240 can move into the second adhesive film 204 in an embedded manner. Due to the flow of the melted second adhesive film 204 and the movement of the solder ribbon 240, the second adhesive film 204 can cover a portion of the thickness of the solder ribbon 240 in a direction perpendicular to the surface where the second adhesive film 204 contacts the solder ribbon 240. To ensure that the solder ribbon 240 can effectively connect to adjacent back contact batteries 230 after subsequent processing, the heating temperature and heating time during the heat treatment process can be controlled to allow the second adhesive film 204 to cover a portion of the thickness of the solder ribbon 240, ensuring that the solder ribbon 240 has a portion protruding from the surface of the second adhesive film 204.

[0056] The solder ribbon 240 is laid on the surface of the second adhesive film 204, and the area of ​​the second adhesive film 204 where the solder ribbon 240 is located is heated to bond the solder ribbon 240 and the second adhesive film 204 together. Pre-fixation of the solder ribbon 240 to the second adhesive film 204 is achieved directly using the second adhesive film 204, which reduces the difficulty and cost of pre-fixation, ensuring a good fixing effect while reducing the overall cost of the photovoltaic module. The second adhesive film 204 only covers a portion of the solder ribbon 240, ensuring that the solder ribbon 240 protrudes from the surface of the second adhesive film 204. This allows the solder ribbon 240 to effectively connect adjacent back contact cells 230 in subsequent processes, preventing open circuit problems in the photovoltaic module and ensuring good reliability.

[0057] In some embodiments, the process parameters for the heat treatment include: a heating temperature of 65 degrees Celsius to 110 degrees Celsius, and / or a heating duration of 0.25 seconds to 1 second.

[0058] The main purpose of heat treatment is to melt the second adhesive film 204 to a certain extent, thereby enabling it to bond to the solder ribbon 240. If the heating temperature during the heat treatment is too low, the second adhesive film 204 will melt less, resulting in poor adhesion between the second adhesive film 204 and the solder ribbon 240. If the heating temperature during the heat treatment is too high, the adhesive film will melt more, and the solder ribbon 240 may shift significantly, making it impossible to accurately fix the solder ribbon 240 in a specific position, which can easily cause short circuits.

[0059] Therefore, the heating temperature during the heat treatment process can be set within the range of 65 degrees Celsius to 110 degrees Celsius, for example, 70 degrees Celsius, 75 degrees Celsius, 85 degrees Celsius, 95 degrees Celsius, or 105 degrees Celsius. By setting the heating temperature within a suitable range, the melting degree of the second adhesive film 204 is ensured to be appropriate, which can effectively achieve the pre-fixation of the solder ribbon 240, while reducing the deformation of the solder ribbon 240 during the heat treatment process and improving the accuracy of the solder ribbon 240 setting.

[0060] Another factor affecting the melting of the adhesive film during the heat treatment process is the heating time. Similar to the effect of heating temperature on the melting and deformation of the adhesive film, if the heating time is too short, the second adhesive film 204 will melt less, which may lead to poor adhesion between the second adhesive film 204 and the solder ribbon 240. If the heating time is too long, the adhesive film will melt more, and the solder ribbon 240 may shift to a greater extent, which may cause the solder ribbon 240 to fail to be accurately fixed in a specific position, which may easily cause short circuit problems.

[0061] Therefore, the heating time during the heat treatment process can be set within the range of 0.25S to 1S, such as 0.3S, 0.35S, 0.45S, 0.6S, 0.75S, or 0.95S. By setting the heating temperature within a suitable range, the melting degree of the second adhesive film 204 is ensured to be appropriate, which can effectively achieve the pre-fixation of the solder ribbon 240, while reducing the deformation and displacement of the solder ribbon 240 during the heat treatment process and improving the accuracy of the solder ribbon 240 setting.

[0062] Furthermore, the heating temperature can be controlled within the range of 65°C to 110°C, while the heating duration can also be controlled within the range of 0.25 seconds to 1 second. This dual control of heating temperature and duration further improves the accuracy of film melting and solder strip 240 setting. When simultaneously controlling heating duration and temperature, a longer heating duration results in a lower heating temperature.

[0063] Reference Figure 1 , Figure 4 and Figure 7 In some embodiments, after pre-fixing the solder ribbons 240 and the second adhesive film 204, the method further includes: providing an insulating portion 250 between at least partially adjacent solder ribbons 240, the insulating portion 250 being spaced apart from the adjacent solder ribbons 240. Figure 7 and Figure 5 Similarly, this is a schematic diagram of the cross-sectional structure of another second adhesive film 204.

[0064] When multiple solder ribbons 240 are provided on the surface of the second adhesive film 204, and each solder ribbon 240 protrudes from the surface of the second adhesive film 204, the coating layer of the solder ribbons 240 will melt during subsequent processes, and the coating layer in the molten state has a certain fluidity. Therefore, when the interval between adjacent solder ribbons 240 is small, the adjacent solder ribbons 240 may become electrically connected due to the flow of the coating layer, which may cause a short circuit in the conductive back contact battery 230.

[0065] Therefore, a plurality of insulating portions 250 can be formed on the surface of the second adhesive film 204 through processes such as dispensing or selective deposition. The insulating portions 250 are located between two adjacent solder strips 240 and are spaced apart from each other. During subsequent lamination, even if the wrapping layer of the solder strips 240 melts and flows, the insulating portions 250 located between adjacent solder strips 240 will block the flowing molten wrapping layer, thereby reducing the probability of electrical connection between adjacent solder strips 240 and improving the safety and reliability of the photovoltaic module. In addition, since the insulating portions 250 are spaced apart from adjacent solder strips 240, the probability of the insulating portions 250 flowing between the solder strips 240 and the grid lines of the back contact cell 230 is also reduced, ensuring the yield of electrical connection between the solder strips 240 and the grid lines of the back contact cell 230.

[0066] In addition, the material of the insulating part 250 can be the same as the material of the second adhesive film 204, or the light transmittance of the material of the insulating part 250 can be greater than that of the material of the second adhesive film 204, so as to avoid the increase of parasitic light absorption of the photovoltaic module caused by the setting of the insulating part 250 and improve the photoelectric conversion efficiency of the photovoltaic module.

[0067] refer to Figure 8 , Figure 8This is a schematic diagram of the photovoltaic module before lamination. The second adhesive film 204 is laid on the surface of the battery structure 203 away from the first cover plate 201, so that at least part of the solder ribbon 240 contacts the positive grid line and the negative grid line on the adjacent back contact battery 230 respectively, and the positive grid line is located on one of the two adjacent back contact batteries 230, and the negative grid line is located on the other.

[0068] After providing or forming a second adhesive film 204 with multiple pre-fixed solder ribbons 240 on its surface, the second adhesive film 204 is laid on the surface of the battery structure 203 away from the first cover plate 201 according to the arrangement of the back contact batteries 230 in the battery structure 203. This allows at least a portion of the solder ribbons 240 laid on the second adhesive film 204 to contact the positive and negative grid lines on adjacent back contact batteries 230 respectively, with the positive grid line located on one of the two adjacent back contact batteries 230 and the negative grid line located on the other. That is, at least a portion of the solder ribbons 240 connect the grid lines with different polarities on adjacent back contact batteries 230, connecting the adjacent back contact batteries 230 in series. Some solder ribbons 240 that correspond only to one back contact battery 230 at the edge of the battery structure 203 form a fixed connection with the positive or negative grid line on the corresponding back contact battery 230 during the lamination process.

[0069] By combining the arrangement of the back contact batteries 230 in the battery structure 203, the second adhesive film 204 is accurately laid on the surface of the battery structure 203 away from the first cover plate 201, so that each solder ribbon 240 can accurately contact two adjacent back contact batteries 230 and connect the grid lines with different polarities located on the two adjacent back contact batteries 230 respectively, ensuring that the adjacent back contact batteries 230 can be effectively connected in series or in parallel after subsequent processing.

[0070] A second cover plate 205 is provided and disposed on the surface of the second adhesive film 204 away from the battery structure 203.

[0071] The second cover plate 205 has a similar function to the first cover plate 201 mentioned above. The materials and functions of the second cover plate 205 will not be described in detail here.

[0072] Reference Figure 8 and Figure 9 The bonding layer of the solder ribbon 240 is laminated using a lamination process, during which the layer melts and forms a fixed connection with the positive and / or negative grid lines. Figure 9 This is a schematic diagram of the overall structure of a photovoltaic module after lamination molding.

[0073] In the formation of such Figure 8After the stacked structure shown, it can be transferred to a lamination machine for lamination processing. The resulting stacked structure will be laminated into the shape shown. Figure 9 The photovoltaic module shown. During the lamination process, the first encapsulant film 202 and the second encapsulant film 204 melt and combine to form an encapsulation film covering the cell structure 203 and the solder ribbon 240; the wrapping layer of the solder ribbon 240 melts during the lamination process, and the molten part flows to the grid lines of the back contact cell 230 that is in contact with the solder ribbon 240. After cooling, it forms a fixed connection with the positive grid lines and / or negative grid lines on the back contact cell 230, thereby realizing the stable interconnection of adjacent back contact cells 230, resulting in a cell structure 203 that connects adjacent back contact cells 230 through the solder ribbon 240. Since the solder ribbon 240 is pre-fixed to the surface of the second encapsulant film 204, the solder ribbon 240 will form a solder area on the side away from the cell structure 203, and the solder area is continuously arranged along the length direction of the solder ribbon 240.

[0074] When the solar cells constituting the battery structure 203 are back-contact cells 230, since the grid lines of the back-contact cells 230 are all on the back side, when the solder ribbon 240 is pre-welded to the grid lines to interconnect adjacent back-contact cells 230, the solder ribbon 240 only generates stress on the back side of the back-contact cells 230, which can easily lead to cell warping. During the lamination molding process to form a photovoltaic module, the back-contact cells 230 in the battery structure 203 are prone to microcracks or even breakage.

[0075] By placing the solder ribbons 240 on the surface of the second adhesive film 204 facing the cell structure 203 and pre-fixing each solder ribbon 240, the solder ribbons 240 can be accurately positioned in a specific location in the formed photovoltaic module without the need for pre-welding to interconnect adjacent back contact cells 230. This achieves accurate interconnection of adjacent back contact cells 230 in the cell structure 203. Then, the module is formed through a lamination process, where the wrapping layer of the solder ribbons 240 melts during lamination and forms a fixed connection with the grid lines. The pressure during lamination and the fixing effect of the adhesive film on the back contact cells 230 offset the welding stress generated by the fixed connection between the solder ribbons 240 and the grid lines, preventing the back contact cells 230 from warping under welding stress. This reduces the probability of microcracks or damage to the photovoltaic module cells, improves the yield of the photovoltaic module, and reduces the manufacturing cost.

[0076] refer to Figure 5 In some embodiments, the ratio of the thickness of the portion of the solder ribbon 240 covered by the second adhesive film 204 to the thickness of the solder ribbon 240 in a direction perpendicular to the surface of the second adhesive film 204 is 0.2 to 0.5.

[0077] In the direction perpendicular to the surface of the second adhesive film 204 where the solder ribbon 240 is located, the thickness of the solder ribbon 240 refers to the maximum interval h1 between any two points on the surface of the solder ribbon 240, and the thickness of the portion of the solder ribbon 240 covered by the second adhesive film 204 refers to the maximum interval h2 between any two points on the surface of the solder ribbon 240 covered by the second adhesive film 204.

[0078] Based on the above analysis and description, the main function of the solder ribbon 240 is to enable the back contact batteries 230 in the battery structure 203 to be connected in series or in parallel according to a preset connection method through subsequent processes. The factors affecting the interconnection effect between adjacent back contact batteries 230 mainly include two aspects: one is the insulation between the solder ribbon 240 and the grid lines to be connected on the back contact batteries 230, and the other is whether the solder ribbon 240 and the grid lines to be connected are accurately connected, including main grids or sub-grids.

[0079] If the thickness of the portion of the solder ribbon 240 covered by the second adhesive film 204 is too large, the exposed surface area of ​​the solder ribbon 240 will be too small. During the lamination process, the molten second adhesive film 204 may easily flow between the solder ribbon 240 and the main grid, resulting in an insufficient contact area or even insulation between the solder ribbon 240 and the main grid. Consequently, the solder ribbon 240 cannot effectively interconnect adjacent back contact cells 230. If the thickness of the portion of the solder ribbon 240 covered by the second adhesive film 204 is too small, the second adhesive film 204 may not effectively fix the solder ribbon 240. The solder ribbon 240 may shift due to the flow of the second adhesive film 204 and the lamination pressure, making it impossible to accurately fix and connect with a specific main grid. This will prevent adjacent back contact cells 230 from achieving effective interconnection.

[0080] Therefore, during the setting of the solder ribbon 240, the ratio of the thickness of the portion of the solder ribbon 240 covered by the second adhesive film 204 to the thickness of the solder ribbon 240 itself is controlled within the range of 0.2 to 0.5, for example, 0.22, 0.25, 0.275, 0.3, 0.35, 0.4, or 0.45, etc. By controlling the thickness ratio of the portion of the solder ribbon 240 covered by the second adhesive film 204 within a suitable range, the probability of the solder ribbon 240 shifting during lamination is reduced, and the flow of the second adhesive film 204 between the solder ribbon 240 and the grid lines to be connected is reduced, increasing the probability of forming good electrical contact between the solder ribbon 240 and the grid lines to be connected, thereby improving the reliability and yield of the photovoltaic module.

[0081] refer to Figure 10 In some embodiments, the step of setting the solder ribbon 340 includes: applying adhesive 341 to a portion of the surface of the second adhesive film 304, and laying the solder ribbon 340 on the surface of the second adhesive film 304 where the adhesive 341 is applied. Figure 10 This is a schematic diagram of the cross-sectional structure of another type of second adhesive film. Figure 10 and Figure 5 Similarly, this is a partial cross-sectional view of the second adhesive film.

[0082] The purpose of laying and pre-fixing the solder ribbon 340 on the second adhesive film 304 is to accurately pre-fix the solder ribbon 340 in the designated position, so that the solder ribbon 340 connecting adjacent cells can contact the positive and negative grid lines on the adjacent back contact cells 330 respectively during the lamination process, with the positive grid line located on one of the two adjacent back contact cells 330 and the negative grid line located on the other. Therefore, when laying and pre-fixing the solder ribbon 340 on the second adhesive film 304, adhesive 341 can be applied to the area on the surface of the second adhesive film 304 where the solder ribbon 340 is to be laid, according to the predetermined laying position of the solder ribbon 340. The adhesive 341 can be an adhesive film of the same material as the second adhesive film 304 and in a highly fluid state, or it can be a transparent adhesive of a different material than the second adhesive film 304. After the adhesive 341 is applied, the solder ribbon 340 is laid on the area where the adhesive 341 is applied, so that the solder ribbon 340 and the second adhesive film 304 can be bonded to each other through the adhesive 341, and the solder ribbon 340 is fixed at a designated position on the surface of the second adhesive film 304.

[0083] The solder ribbon 340 is fixed to the surface of the second adhesive film 304 by applying adhesive 341. Since the adhesive film 341 has its own adhesive ability, there is no need to heat the second adhesive film 304, which avoids the deformation of the solder ribbon 340 due to heat treatment, further improving the accuracy of the solder ribbon 340 setting and facilitating the formation of an accurate fixed connection between the solder ribbon 340 and the grid line during the lamination process.

[0084] It is worth mentioning that, along the length direction of the solder strip 340, the area on the surface of the second adhesive film 304 corresponding to each solder strip 340 is a continuous area. During the application of adhesive 341, the adhesive 341 can cover the entire continuous area, or it can cover a part of the continuous area. For example, the continuous area can be composed of adhesive areas and non-adhesive areas arranged alternately along the length direction, with the adhesive areas covered by adhesive 341 and the non-adhesive areas covered by adhesive 341 having an area of ​​0. Alternatively, the continuous area can be composed of adhesive areas and non-adhesive areas arranged alternately along the width direction, with the adhesive areas covered by adhesive 341 and the non-adhesive areas covered by adhesive 341 having an area of ​​0.

[0085] refer to Figure 11The step of applying adhesive 441 includes: forming a plurality of grooves 442 on the surface of the second adhesive film 404; applying adhesive 441 to at least a portion of the surface of the second adhesive film 404 exposed in each groove 442; and the method of laying solder ribbon 440 includes: laying solder ribbon 440 in the grooves 442 coated with adhesive 441. Figure 11 This is a schematic diagram of the cross-sectional structure of another type of second adhesive film. Figure 11 and Figure 5 A partial cross-sectional view, similar to that of the second adhesive film.

[0086] Based on the above analysis and description, the purpose of pre-fixing the solder ribbon 440 to the surface of the second adhesive film 404 is to accurately fix the solder ribbon 440 in the designated position, ensuring that the solder ribbon 440 can effectively connect adjacent battery cells after subsequent lamination. However, when the solder ribbon 440 is fixed directly on the surface of the second adhesive film 404 by applying adhesive 441, the fixing effect of the adhesive on the solder ribbon 440 is limited, and the probability of the solder ribbon 440 shifting during the lamination process is still relatively high.

[0087] Therefore, during the laying of the solder ribbon 440, the second adhesive film 404 is selectively grooved according to the predetermined laying position of the solder ribbon 440, forming multiple grooves 442 on the surface of the second adhesive film 404, each groove 442 corresponding to one solder ribbon 440. Then, adhesive 441 is applied to the surface of the second adhesive film 404 exposed in each groove 442. The solder ribbon 440 is then laid into the groove 442 coated with adhesive 441. The adhesive 441 and the groove 442 together pre-fix the solder ribbon 440, greatly enhancing the pre-fixation effect of the solder ribbon 440 on the surface of the second adhesive film 404, reducing the probability of the solder ribbon 440 shifting during the lamination process, and improving the reliability of the photovoltaic module.

[0088] When applying adhesive 441 to the surface of the second adhesive film 404 exposed by the slot 442, the adhesive 441 can cover the entire surface of the second adhesive film 404 exposed by the slot 442, thereby maximizing the fixing effect of the adhesive 441 on the solder ribbon 440; alternatively, it can only cover a portion of the surface of the second adhesive film 404 exposed by the slot 442, for example, along the length direction of the solder ribbon 440, the adhesive 441 forms alternating patterns on the surface of the second adhesive film 404 exposed by the slot 442. The adhesive and non-adhesive areas are arranged in alternating patterns. The adhesive areas are covered by adhesive 441, while the non-adhesive areas are free of adhesive 441. Alternatively, along the width direction of the solder ribbon 440, the adhesive 441 forms alternating adhesive and non-adhesive areas on the surface of the second adhesive film 404 exposed by the groove 442. The adhesive areas are covered by adhesive 441, while the non-adhesive areas are free of adhesive 441. This ensures the fixing effect of the solder ribbon 440 while reducing the amount of adhesive 441 used, thereby reducing the overall manufacturing cost of the photovoltaic module.

[0089] In some embodiments, the ratio between the groove depth of the groove 442 and the thickness of the solder strip 440 in a direction perpendicular to the surface of the second adhesive film 404 is 0.1 to 0.5.

[0090] In the direction perpendicular to the surface of the second adhesive film 404 where the groove 442 is located, the groove depth of the groove 442 refers to the distance h3 between any point on the surface of the groove 442 and the surface of the second adhesive film 404 where the groove 442 is located, and the thickness of the solder strip 440 refers to the maximum distance h4 between any two points on the surface of the solder strip 440.

[0091] When the ratio between the depth of the groove 442 and the thickness of the solder strip 440 is too small, the groove 442 primarily uses its sidewalls that engage with the solder strip 440 to fix it. Therefore, the fixing effect provided by the groove 442 is limited. Even with the adhesive 441, the groove 442 cannot effectively fix the solder strip 440, and the probability of the solder strip 440 shifting during lamination is high. When the ratio between the depth of the groove 442 and the thickness of the solder strip 440 is too large, the surface area of ​​the second adhesive film 404 exposed by the groove 442 is too large, requiring an excessive amount of adhesive 441. Furthermore, due to the excessive depth of the groove 442, the adhesive loss of the second adhesive film 404 is significant, which may lead to problems such as insufficient adhesive or air bubbles during lamination.

[0092] Therefore, during the process of forming the groove 442 on the second adhesive film 404, the ratio between the groove depth of the groove 442 and the thickness of the solder ribbon 440 can be controlled within the range of 0.1 to 0.5, for example, 0.12, 0.15, 0.18, 0.2, 0.25, 0.3, 0.375, or 0.45, along with the direction perpendicular to the surface of the second adhesive film 404 where the groove 442 is located. By setting the ratio between the groove depth of the groove 442 and the thickness of the solder ribbon 440 within a suitable range, the fixing effect of the groove 442 and the adhesive 442 on the solder ribbon 440 is improved, greatly reducing the probability of the solder ribbon 440 shifting during the lamination process. Simultaneously, the amount of adhesive 441 used and the adhesive loss of the second adhesive film 404 are minimized, reducing the probability of bubbles or missing adhesive in the encapsulation film formed by lamination. This improves the quality of the encapsulation film and reduces the manufacturing cost of photovoltaic modules.

[0093] In summary, this application provides a method for manufacturing photovoltaic modules. Solder ribbons are pre-positioned on the surface of the second adhesive film facing the cell structure, and each solder ribbon is pre-fixed to ensure accurate positioning of the solder ribbons in the formed photovoltaic module, thereby achieving electrical connection between adjacent cells. Then, the second adhesive film with the solder ribbons is laid onto the surface of the cell structure, so that each solder ribbon contacts two main grids with different polarities and connects to two adjacent back-contact cells. The module is then formed through a lamination process, during which the solder ribbons melt and form a fixed connection with the main grids. By melting the solder ribbons and fixing them to the main grids during lamination, the pressure during lamination and the fixing effect of the adhesive film on the cells prevent warping of the cells under welding stress, thereby reducing the probability of microcracks or damage to the photovoltaic modules, improving the yield of the photovoltaic modules, and reducing manufacturing costs.

[0094] This application also provides a photovoltaic module, as shown in the embodiments. Figure 9 ,include:

[0095] A first cover plate 201, a battery structure 203, and a second cover plate 205 are stacked along a first direction, and an encapsulation film is located between the first cover plate 201 and the second cover plate 205 and covers the battery structure 203. The battery structure 203 includes a plurality of back contact batteries 230 and a plurality of solder ribbons 240. The surface of each back contact battery 230 facing the first cover plate 201 includes a plurality of main grids. Each solder ribbon 240 is in contact with two main grids with different polarities, and the two main grids with different polarities are located on different back contact batteries 230 in two adjacent back contact batteries 230. Along the first direction, the side of the solder ribbon 240 away from the first cover plate 201 includes a solder area, and the solder area is continuously arranged along the extension direction of the long side of the solder ribbon 240.

[0096] Since the solder ribbon 240 is pre-fixed on the adhesive film between the second cover plate 205 and the battery structure 203 and melts during the lamination process, it forms a fixed connection with the two main grids with different polarities on the different back contact cells 230. While accurately connecting the two adjacent back contact cells 230, a solder area is formed on the side of the solder ribbon 240 away from the first cover plate 201, which is continuously arranged along the long side of the solder ribbon 240. This improves the uniformity of the width of the solder ribbon 240 along the length direction, avoids the increase in resistance caused by the solder interval of the solder ribbon 240, and reduces the carrier transport loss of the solder ribbon 240. At the same time, since the adjacent back contact cells 230 are interconnected during the lamination process, the stress caused by the solder ribbon 240 on the back contact cells 230 is offset by the adhesive film and lamination pressure, which greatly reduces the probability of the back contact cells 230 warping or even microcracks, greatly improves the reliability of the photovoltaic module, and reduces the module manufacturing cost.

[0097] In some embodiments, the melting point of the solder strip 240 is between 120 and 160 degrees Celsius.

[0098] The solder ribbon 240 connects to adjacent back contact cells 230 by melting during lamination and forming a fixed connection with the main grid on the back contact cell 230. However, the lamination temperature during lamination is limited. Therefore, to ensure the reliability of the fixed connection between the solder ribbon 240 and the main grid, a solder ribbon 240 with a low melting point needs to be selected to ensure that the solder ribbon 240 can melt and generate sufficient solder during lamination. Therefore, the melting point of the solder ribbon 240 can be controlled within the range of 120 degrees Celsius to 160 degrees Celsius, for example, 125 degrees Celsius, 130 degrees Celsius, 137.5 degrees Celsius, 145 degrees Celsius, or 155 degrees Celsius.

[0099] In some embodiments, the solder strip 240 includes a conductive core and a wrapping layer covering the conductive core, the wrapping layer having a melting point of 120 to 160 degrees Celsius.

[0100] Typically, solder ribbon 240 consists of a conductive core with good conductivity and a wrapping layer that melts and forms a large amount of solder covering the conductive core. Since the melting point of the conductive core is usually fixed and relatively high, the melting point of the wrapping layer can be adjusted to be within the range of 120 to 160 degrees Celsius by adjusting the solder ratio in the wrapping layer. For example, the melting point of the wrapping layer can be set to 122.5 degrees Celsius, 125 degrees Celsius, 135 degrees Celsius, 142.5 degrees Celsius, or 148 degrees Celsius. By setting the melting point of the wrapping layer of solder ribbon 240 within a suitable range, good conductivity of solder ribbon 240 is ensured, and sufficient solder is generated during the lamination process, thus forming a good fixed connection with the main gate. Simultaneously, a continuous, uninterrupted solder area is formed along the long side of solder ribbon 240, reducing the resistance of solder ribbon 240.

[0101] Furthermore, the cross-section of the solder strip 240 can be circular, rectangular, or other polygonal. For ease of description, this application uses a circular shape as an example.

[0102] It is not difficult to see that this embodiment is a photovoltaic module structure embodiment corresponding to the photovoltaic module preparation method embodiment. The details in this embodiment are also applicable to the photovoltaic module preparation method embodiment, and the details in the photovoltaic module preparation method embodiment are also applicable to this embodiment. The relevant details will not be repeated here.

[0103] Although this application discloses preferred embodiments as described above, it is not intended to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of this application, without deviating from the spirit and scope of this application. Therefore, the scope of protection of this application should be determined by the scope defined by the claims of this application.

Claims

1. A method for manufacturing a photovoltaic module, characterized in that, include: A first cover plate, a first adhesive film, and a battery structure are provided and stacked along a first direction. The battery structure includes a plurality of back contact batteries, and the surface of each back contact battery away from the first cover plate includes positive grid lines and negative grid lines. A second adhesive film is provided, and at least one solder strip is disposed on the surface of the second adhesive film. The solder strip has a conductive core and a wrapping layer covering the conductive core, and the solder strip and the second adhesive film are pre-fixed. The second adhesive film is laid on the surface of the battery structure away from the first cover plate, such that at least a portion of the solder strip contacts the positive grid line and the negative grid line on the adjacent back contact battery respectively, and the positive grid line is located on one of the two adjacent back contact batteries, and the negative grid line is located on the other. A second cover plate is provided and disposed on the surface of the second adhesive film away from the battery structure; The coating layer is formed by lamination process, which melts during the lamination process and forms a fixed connection with the positive grid line and / or the negative grid line.

2. The photovoltaic module manufacturing method according to claim 1, characterized in that, The steps for setting the solder strip include: The welding ribbon is laid on the surface of the second adhesive film; The second adhesive film in the area where the solder ribbon is located is heated to bond the solder ribbon and the second adhesive film to each other, and the second adhesive film covers the solder ribbon to a multiple thickness in a direction perpendicular to the surface of the second adhesive film.

3. The photovoltaic module manufacturing method according to claim 2, characterized in that, In a direction perpendicular to the surface of the second adhesive film, the ratio of the thickness of the portion of the solder ribbon covered by the second adhesive film to the thickness of the solder ribbon is 0.2 to 0.

5.

4. The photovoltaic module manufacturing method according to claim 2, characterized in that, The process parameters for the heat treatment include: a heating temperature of 65 degrees Celsius to 110 degrees Celsius, and / or a heating duration of 0.25 seconds to 1 second.

5. The photovoltaic module manufacturing method according to claim 1, characterized in that, The steps for setting the solder strip include: Adhesive is applied to a portion of the surface of the second adhesive film, and the welding ribbon is laid on the adhesive-coated surface of the second adhesive film.

6. The photovoltaic module manufacturing method according to claim 5, characterized in that, The steps for applying glue include: Multiple grooves are formed on the surface of the second adhesive film; Apply adhesive to at least a portion of the surface of the second adhesive film exposed by each of the grooves; The method of laying the welding strip includes: laying the welding strip in the groove coated with adhesive.

7. The photovoltaic module manufacturing method according to claim 6, characterized in that, In a direction perpendicular to the surface of the second adhesive film, the ratio between the groove depth and the thickness of the solder strip is 0.1 to 0.

5.

8. The photovoltaic module manufacturing method according to claim 1, characterized in that, After pre-fixing the solder strip and the second adhesive film, the process further includes: An insulating portion is provided between at least partially adjacent solder strips, the insulating portion being spaced apart from the adjacent solder strips.

9. A photovoltaic module, characterized in that, The photovoltaic module is formed by the photovoltaic module manufacturing method according to any one of claims 1 to 8. The photovoltaic module includes: a first cover plate, a cell structure, and a second cover plate stacked along a first direction, and an encapsulation film located between the first cover plate and the second cover plate and covering the cell structure; the cell structure includes a plurality of back contact cells and a plurality of solder strips, each of the back contact cells having a positive grid line and a negative grid line on its surface facing the second cover plate, at least a portion of the solder strips being in contact with the positive grid line and the negative grid line on adjacent back contact cells respectively, and the positive grid line being located on one of two adjacent back contact cells, and the negative grid line being located on the other. Along the first direction, the side of the solder strip away from the first cover plate includes a solder area, which is continuously arranged along the extension direction of the long side of the solder strip.

10. The photovoltaic module according to claim 9, characterized in that, The melting point of the welding strip is 120 to 160 degrees Celsius.

11. The photovoltaic module according to claim 10, characterized in that, The welding strip includes a conductive inner core and a wrapping layer covering the conductive inner core, the melting point of which is between 120 and 160 degrees Celsius.

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