Photovoltaic module

Abstract

The utility model relates to the field of photovoltaic technology, and especially relates to a photovoltaic assembly. The photovoltaic module comprises front glass, a front adhesive film, a battery unit, a threading adhesive film and a back plate which are sequentially stacked. Wherein the threading adhesive film comprises an adhesive film layer and a welding wire, the adhesive film layer is provided with a first end face and a second end face which are oppositely arranged, one side of the welding wire is inserted into the adhesive film layer, the other side of the welding wire protrudes out of the second end face and is in conductive connection with the battery unit, and the first end face is connected with the back plate in an adhesive mode. According to the photovoltaic module, the phenomena of warping and cracking of the battery units can be reduced, the damage to the battery units is reduced, the working efficiency and the product yield are improved, and the purpose of saving the cost is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic technology field especially relates to a photovoltaic module. BACKGROUND

[0002] At present, in the preparation process of the photovoltaic module with the back contact cell (BC cell), the traditional hot infrared welding method is still used to weld the solder strip and the cell piece to form the cell string. Since the grid lines of the back contact cell are all arranged on the back surface of the cell piece, after the welding process, the alloyed solder joint cools and shrinks, thereby causing the local stress concentration on the back surface of the cell piece, and the cell piece is easily warped or even cracked, which reduces the operation efficiency and increases the cost. At the same time, the traditional hot infrared welding technology needs to use the stringer to frequently move the cell piece on the assembly line, which is easy to scratch the surface of the cell piece, thereby causing the EL detection to be poor, and reducing the product yield of the photovoltaic module.

[0003] Therefore, it is urgent to design a photovoltaic module to solve the above technical problems. SUMMARY

[0004] The utility model discloses a photovoltaic module, reduces the phenomenon that the cell unit warps, cracks, reduces the damage to the cell unit, improves the operation efficiency and product yield, reaches the purpose of saving the cost.

[0005] To achieve this purpose, the utility model adopts the following technical scheme:

[0006] The utility model provides a photovoltaic module, including the front glass, front adhesive film, cell unit, wire -through adhesive film and backboard that set gradually.

[0007] The wire -through adhesive film includes adhesive film layer and solder wire, the adhesive film layer has the first end face and the second end face that set oppositely, one side of the solder wire inserts the inside of the adhesive film layer, the other side of the solder wire protrudes from the second end face and is electrically connected with the cell unit, and the first end face is adhesively connected with the backplate.

[0008] As an optional technical scheme of a photovoltaic module, the solder wire includes the head and the tail that are connected with each other, the head and part of the tail are inserted into the inside of the adhesive film layer, and the other part of the tail protrudes from the second end face and is electrically connected with the cell unit.

[0009] The cross-sectional area of the head is less than the cross-sectional area of the tail.

[0010] As an optional technical scheme of a photovoltaic module, the connecting place of the head and the tail is provided with a retreat stop portion, and the retreat stop portion is configured to prevent the solder wire from falling off from the adhesive film layer.

[0011] As an optional technical solution of the photovoltaic module, the retreat prevention part has a retreat prevention surface and a connecting surface connected to each other, the retreat prevention surface is adjacent to the side surface of the head part, and the connecting surface is connected to the end surface of the tail part.

[0012] The connecting surface is inclined towards the radial direction of the solder wire, and the retreat prevention surface is parallel to the second end surface of the adhesive film layer.

[0013] As an optional technical solution of the photovoltaic module, the adhesive film layer includes a first adhesive film layer and a second adhesive film layer, the first adhesive film layer and the second adhesive film layer are connected, the pre-crosslinking index of the first adhesive film layer is less than the pre-crosslinking index of the second adhesive film layer; the first adhesive film layer is configured to be connected to the back plate, and the second adhesive film layer is configured to be inserted into part of the solder wire.

[0014] As an optional technical solution of the photovoltaic module, the outer periphery of the solder wire is wrapped with a tin-lead-bismuth alloy layer.

[0015] As an optional technical solution of the photovoltaic module, the cell is a back contact cell, the back surface of the back contact cell is provided with a plurality of grid lines, the plurality of grid lines are arranged at equal intervals along a first direction, and the grid lines extend along a second direction, the solder wire is connected to the grid lines, and the solder wire extends along the first direction, and the first direction is perpendicular to the second direction.

[0016] As an optional technical solution of the photovoltaic module, the solder wire includes a plurality of positive electrode solder wires and a plurality of negative electrode solder wires, the positive electrode solder wires and the negative electrode solder wires are arranged alternately along the second direction; the back surface of the back contact cell is provided with a plurality of positive electrode grid lines and a plurality of negative electrode grid lines, and the positive electrode grid lines and the negative electrode grid lines are arranged alternately along the second direction.

[0017] The positive electrode solder wires are connected to the positive electrode grid lines, and the negative electrode solder wires are connected to the negative electrode grid lines.

[0018] As an optional technical solution of the photovoltaic module, a plurality of first partition sites and a plurality of second partition sites are formed on the wire penetrating adhesive film, the first partition sites and the second partition sites are arranged staggeredly along the second direction, the first partition sites are configured to partition the positive electrode solder wires, and the second partition sites are configured to partition the negative electrode solder wires.

[0019] As an optional technical solution of the photovoltaic module, the cell is a bifacial cell, and the back plate is a back glass.

[0020] As an optional technical solution of the photovoltaic module, the front glass, the front adhesive film, the cell unit, the wire penetrating adhesive film and the back plate are sequentially stacked to form a laminated part, and the photovoltaic module further comprises a frame, and the frame is arranged around the laminated part.

[0021] The beneficial effects of the present application at least include:

[0022] The utility model provides a kind of photovoltaic module, which comprises front glass, front adhesive film, cell unit, wire penetrating adhesive film and back plate arranged sequentially in layers. The wire penetrating adhesive film includes an adhesive film layer and a welding wire. The adhesive film layer has a first end face and a second end face arranged oppositely. One side of the welding wire is inserted into the adhesive film layer, and the other side of the welding wire protrudes from the second end face and is electrically connected to the cell unit. The first end face is adhesively connected to the back plate.

[0023] The above, the setting of the wire penetrating adhesive film in the present application achieves the purpose of canceling the back adhesive film and the welding strip in the conventional technology. Specifically, one side of the welding wire is embedded in the adhesive film layer, and the other side of the welding wire protrudes from the second end face of the adhesive film layer. This not only improves the stability and reliability of the welding wire and the adhesive film layer, but also reduces or avoids the risk of the welding wire falling off. At the same time, the welding wire protruding from the second end face can be alloyed with the cell unit during the lamination process, thereby realizing ohmic contact between the welding wire and the cell unit and ensuring the collection and export of current. Compared with the prior art, in the present application, the wire penetrating adhesive film is arranged between the back plate and the cell unit, and the welding wire in the wire penetrating adhesive film is in ohmic contact with the cell unit during the lamination process, so that the current in the cell unit can be collected and exported. The preparation process of the photovoltaic module does not require the participation of welding equipment such as string welding machine in the conventional technology, thereby reducing the phenomenon of local stress concentration on the back of the cell unit and reducing the phenomenon of cell unit warping or even cracking. The design of the wire penetrating adhesive film in the present application starts directly from the layout process. The wire penetrating adhesive film is a whole string connection structure. The cell units are placed on the front adhesive film according to the layout order, and then the wire penetrating adhesive film is covered on the cell units. This avoids the frequent movement of the cell units by the string welding machine in the conventional technology, improves the work efficiency, reduces the scratching phenomenon on the surface of the cell units, improves the product yield of the photovoltaic module, and achieves the purpose of saving cost. BRIEF DESCRIPTION OF DRAWINGS

[0024] To more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the contents of the embodiments of the present application and these drawings.

[0025] Figure 1 is an exploded view of the photovoltaic module provided by the embodiment of the present application;

[0026] Figure 2 is a structural schematic view of the photovoltaic module (part of the frame is not shown) provided by the embodiment of the present application;

[0027] Figure 3 is Figure 2 is a partial enlarged view of A in FIG.

[0028] Figure 4 is a structural schematic view of the wire penetrating adhesive film provided by the embodiment of the present application;

[0029] Figure 5 is a sectional view of the wire penetrating adhesive film provided by the embodiment of the present application;

[0030] Figure 6 is Figure 5 is a partial enlarged view of B in FIG.

[0031] Reference signs

[0032] 100, front glass; 200, front adhesive film; 300, cell unit;

[0033] 400, wire penetrating adhesive film; 410, adhesive film layer; 4101, first end face; 4102, second end face; 4103, first partition position; 4104, second partition position; 420, welding wire; 4201, head; 4202, tail; 4203, retreat stop portion; 42031, retreat stop face; 42032, connecting face; 4204, positive electrode welding wire; 4205, negative electrode welding wire; 500, back plate; 600, frame; 700, junction box. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0036] It should be noted that like reference numerals and letters refer to like items throughout the twelve drawings, and once an item is defined in one drawing, it need not be further defined and explained in the subsequent drawings.

[0037] In the description of the utility model, it needs to be explained that the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship commonly placed when the utility model product is used, and is merely for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third" and the like are merely used for differentiation in description and cannot be understood as indicating or implying relative importance. In the description of the utility model, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0038] In the description of the utility model, it also needs to be explained that, unless otherwise explicitly specified and limited, the terms "set", "connected" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected, can be mechanically connected, or can be electrically connected. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0039] In the utility model, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "above", "upper" and "upper surface" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "under" and "under surface" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0040] The embodiments of the utility model are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model.

[0041] The embodiment provides a photovoltaic module, reduces the phenomenon that the cell unit is warped and cracked, reduces the damage to the cell unit, improves the operation efficiency and product yield, and achieves the purpose of saving cost.

[0042] like Figures 1-5 As shown, the photovoltaic module mainly includes a front glass 100, a front encapsulating film 200, a battery cell 300, a wire-threaded encapsulating film 400, and a backsheet 500 stacked sequentially. The wire-threaded encapsulating film 400 includes an encapsulating film layer 410 and a welding wire 420. The encapsulating film layer 410 has a first end face 4101 and a second end face 4102 disposed opposite to each other. One side of the welding wire 420 is inserted into the encapsulating film layer 410, and the other side of the welding wire 420 protrudes from the second end face 4102 and is electrically connected to the battery cell 300. The first end face 4101 is bonded to the backsheet 500.

[0043] Based on the above design, in this embodiment, the use of the wire-threaded adhesive film 400 eliminates the need for the back adhesive film and solder ribbon in traditional technologies. Specifically, one side of the solder wire 420 is embedded within the adhesive film layer 410, while the other side protrudes from the second end face 4102 of the adhesive film layer 410. This not only improves the stability and reliability of the embedding of the solder wire 420 into the adhesive film layer 410, reducing or avoiding the risk of the solder wire 420 falling off, but also allows the solder wire 420 protruding from the second end face 4102 to alloy with the battery cell 300 during the lamination process, thereby achieving ohmic contact between the solder wire 420 and the battery cell 300 and ensuring current collection and conduction. During the lamination process, both the first end face 4101 and the second end face 4102 of the adhesive film layer 410 can melt to a certain extent, thereby achieving stable bonding between the adhesive film layer 410 and the backsheet 500 and the battery cell 300, improving the overall integrity and reliability of the photovoltaic module.

[0044] Compared with existing technologies, this embodiment provides a wire-threaded adhesive film 400 between the backsheet 500 and the cell unit 300. During the lamination process, the welding wire 420 in the wire-threaded adhesive film 400 makes ohmic contact with the cell unit 300, enabling the current in the cell unit 300 to be collected and discharged. The photovoltaic module manufacturing process in this embodiment does not require the participation of welding equipment such as stringers, thereby reducing localized stress concentration on the back of the cell unit 300 and reducing the occurrence of cell unit 300 warping or even cracking. The design of the wire-threaded adhesive film 400 in this embodiment starts directly from the layout process. The wire-threaded adhesive film 400 is a string-connected structure. The cell units 300 are placed directly on the front adhesive film 200 according to the layout order, and then the wire-threaded adhesive film 400 is covered on the cell units 300. This avoids the frequent movement of the cell units 300 using a stringer in traditional technologies, improving work efficiency, reducing scratches on the surface of the cell units 300, increasing the product yield of the photovoltaic module, and saving costs.

[0045] like Figure 5As shown, in the embodiment, the welding wire 420 comprises a head portion 4201 and a tail portion 4202 connected with each other, the head portion 4201 and part of the tail portion 4202 are inserted into the inside of the adhesive film layer 410, and the tail portion 4202 protrudes from the second end surface 4102 and is in conductive connection with the battery cell 300 at the end away from the head portion 4201 (i.e., the other part of the tail portion 4202), which can on the one hand improve the stability and reliability of the connection between the welding wire 420 and the adhesive film layer 410, and reduce or avoid the risk of the welding wire 420 falling off, and on the other hand ensure that the tail portion 4202 is in ohmic contact with the battery cell 300 during the lamination process, so as to realize the collection of current.

[0046] Further, the cross-sectional area of the head portion 4201 in the embodiment is smaller than that of the tail portion 4202, which is conducive to the head portion 4201 of the welding wire 420 piercing the second end surface 4102 of the adhesive film layer 410 and being accommodated inside the adhesive film layer 410, and improves the processing and manufacturing efficiency of the wire-inserted adhesive film 400. At the same time, it can also increase the area of the connection between the welding wire 420 and the battery cell 300, realize good ohmic contact, and reduce the phenomenon of open circuit or virtual connection.

[0047] Further, please continue to refer to Figure 5 The connection between the head portion 4201 and the tail portion 4202 in the embodiment is provided with a retreat-stop portion 4203, which is configured to prevent the welding wire 420 from falling off from the adhesive film layer 410, and improve the stability and reliability of the connection between the welding wire 420 and the adhesive film layer 410. Specifically, the provision of the retreat-stop portion 4203 can increase the contact area with the adhesive film layer 410, thereby reducing the risk of the welding wire 420 falling off from the adhesive film layer 410.

[0048] Specifically, as Figure 6 shown, the retreat-stop portion 4203 has a retreat-stop surface 42031 and a connecting surface 42032 connected with each other, the retreat-stop surface 42031 is adjacent to the side surface of the head portion 4201, and the connecting surface 42032 is connected with the end surface of the tail portion 4202; the connecting surface 42032 is inclined toward the radial direction of the welding wire 420, and the retreat-stop surface 42031 is parallel to the second end surface 4102 of the adhesive film layer 410, which can as much as possible increase the contact area between the retreat-stop surface 42031 and the adhesive film layer 410, and reduce the risk of the welding wire 420 falling off from the adhesive film layer 410. At the same time, the connecting surface 42032 is inclined toward the radial direction of the welding wire 420, which can play a certain guiding role when the welding wire 420 is inserted into the adhesive film layer 410, improve the working efficiency of the welding wire 420 inserted into the adhesive film layer 410, and save time and effort.

[0049] Optionally, the retreat-stop portion 4203 can be provided in multiple, and the retreat-stop portion 4203 in the embodiment can be provided in the form of a ring groove, a groove or the like.

[0050] The adhesive film layer 410 in the embodiment includes a first adhesive film layer and a second adhesive film layer, the first adhesive film layer and the second adhesive film layer are connected, the pre-crosslinking index of the first adhesive film layer is less than the pre-crosslinking index of the second adhesive film layer; the first adhesive film layer is configured to be connected with the backboard 500, and the second adhesive film layer is configured to be inserted into the partial solder wire 420. That is, in the laminating process, the flowability of the second adhesive film layer is less than the flowability of the first adhesive film layer. In other words, the stiffness of the second adhesive film layer in the embodiment is greater than the stiffness of the first adhesive film layer. In this way, in the laminating process, the flowability of the second adhesive film layer can be reduced as much as possible to reduce the phenomenon of deviation of the solder wire 420. At the same time, the first adhesive film layer can also have good flowability to ensure that the first adhesive film layer has good adhesion with the backboard 500, improve the integrity and reliability of the photovoltaic module, and prolong the service life.

[0051] Exemplarily, the second adhesive film layer in the embodiment can be preprocessed by heat radiation to make the pre-crosslinking value of the second adhesive film layer reach 40% to improve the stiffness of the second adhesive film layer and reduce the flowability.

[0052] Optionally, the outer periphery of the solder wire 420 in the embodiment is wrapped with a tin-lead-bismuth alloy layer to make the solder wire 420 have the characteristics of low-temperature melting alloy, so as to ensure that the solder wire 420 can have good ohmic contact with the battery cell 300 in the laminating process. Optionally, the proportion of bismuth metal in the tin-lead-bismuth alloy layer in the embodiment can be set to 14%-26%.

[0053] Optionally, the battery cell 300 in the embodiment is a back contact battery, the back surface of the back contact battery is provided with a plurality of grid lines (not shown in the figure), the plurality of grid lines are arranged at equal intervals along a first direction, and the grid lines extend along a second direction, the solder wire 420 is connected with the grid lines, and the solder wire 420 extends along the first direction, the first direction and the second direction are perpendicular to each other. The first direction is the X-axis direction in the figure, and the second direction is the Y-axis direction in the figure. Figure 4 Figure 4 The extension direction of the solder wire 420 is perpendicular to the grid lines in the back contact battery, and the grid lines can collect the current generated in the back contact battery under the photovoltaic effect and be collected and led out through the solder wire 420.

[0054] Optionally, the grid lines provided on the back surface of the back contact battery are fine grid lines.

[0055] As Figure 4 ​As shown, the welding wire 420 in the embodiment includes a plurality of positive electrode welding wires 4204 and a plurality of negative electrode welding wires 4205, the positive electrode welding wires 4204 and the negative electrode welding wires 4205 are arranged alternately along the second direction; the back surface of the back contact battery is provided with a plurality of positive electrode grid lines and a plurality of negative electrode grid lines (the positive electrode grid lines and the plurality of negative electrode grid lines are not shown in the figure), the positive electrode grid lines and the negative electrode grid lines are arranged alternately along the second direction. The positive electrode welding wire 4204 is connected with the positive electrode grid line, and the negative electrode welding wire 4205 is connected with the negative electrode grid line. By arranging the positive electrode grid line and the negative electrode grid line on the back surface of the back contact battery, the stability and reliability of the connection between the back contact battery and the positive electrode welding wire 4204 and the negative electrode welding wire 4205 are improved, and the phenomenon of false connection is reduced.

[0056] Optionally, the positive electrode grid line and the negative electrode grid line on the back surface of the back contact battery are main grid lines.

[0057] It can be understood that the positive surface of the back contact battery in the embodiment is designed without main grid lines, and the main grid lines (including the positive main grid line and the negative main grid line) on the back surface can be selectively designed according to actual needs, that is, the main grid line can be arranged on the back surface of the back contact battery to improve the reliability of the connection with the welding wire 420; or the main grid line can not be arranged to reduce the shielding of the light receiving area and improve the photoelectric conversion efficiency, thereby improving the power generation power of the photovoltaic module.

[0058] As shown in the figure, Figure 4 In the embodiment, a plurality of first partition positions 4103 and a plurality of second partition positions 4104 are arranged on the adhesive film 400, the first partition positions 4103 and the second partition positions 4104 are arranged alternately along the second direction, the first partition positions 4103 are configured to partition the positive electrode welding wire 4204, and the second partition positions 4104 are configured to partition the negative electrode welding wire 4205. In other words, through the arrangement of the first partition positions 4103 and the second partition positions 4104, the welding wire 420 in the embodiment can realize periodic intermittent arrangement, thereby meeting the interdigital design requirement of the back contact battery, which can ensure the connection between the same electrodes in the back contact battery and avoid the short circuit problem caused by the connection between different electrodes.

[0059] Optionally, the first partition position 4103 and the second partition position 4104 can be arranged as a circular hole penetrating the first end surface 4101 and the second end surface 4102 of the adhesive film layer 410.

[0060] It should be noted that the interdigital design structure of the back contact battery in the embodiment belongs to the prior art in the field, and the specific structure will not be described here.

[0061] Optionally, in some alternative embodiments, the battery unit 300 can also be configured as a single-sided battery or a double-sided battery. When the battery unit 300 is a single-sided battery, the back panel 500 is made of an opaque material, such as TPT or PET. When the battery unit 300 is a double-sided battery, the back panel 500 is a glass back, which facilitates the back of the battery unit 300 receiving light.

[0062] like Figures 1-3 As shown, in this embodiment, the front glass 100, the front adhesive film 200, the battery cell 300, the fiber adhesive film 400, and the back sheet 500 are stacked in sequence to form a laminate. The photovoltaic module also includes a frame 600 and a junction box 700. The frame 600 is disposed around the laminate, and the junction box 700 is disposed on the back sheet 500.

[0063] The frame 600 enhances the mechanical strength of the photovoltaic module and extends its lifespan. The junction box 700 facilitates current output and routing to the inverter or electrical equipment.

[0064] Obviously, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

[0065] Note that in the description of this specification, the references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A photovoltaic module, characterized by, The battery cell (300) is a back contact battery, and a back surface of the back contact battery is provided with a plurality of grid lines, the plurality of grid lines are arranged at equal intervals along a first direction, and the grid lines extend along a second direction, the welding wire (420) is connected with the grid lines, and the welding wire (420) extends along the first direction, and the first direction and the second direction are perpendicular to each other. The welding wire (420) includes a head portion (4201) and a tail portion (4202) connected with each other, the head portion (4201) and part of the tail portion (4202) are inserted into the inside of the adhesive film layer (410), and the other part of the tail portion (4202) protrudes from the second end surface (4102) and is in conductive connection with the battery cell (300).

2. The photovoltaic module of claim 1, wherein, The cross-sectional area of the head portion (4201) is smaller than that of the tail portion (4202). The connection portion of the head portion (4201) and the tail portion (4202) is provided with a retreat-stop portion (4203) configured to prevent the welding wire (420) from falling off from the adhesive film layer (410).

3. The photovoltaic module of claim 2, wherein, The retreat-stop portion (4203) has a retreat-stop surface (42031) and a connecting surface (42032) connected with each other, the retreat-stop surface (42031) is adjacent to the side surface of the head portion (4201), and the connecting surface (42032) is connected with the end surface of the tail portion (4202).

4. The photovoltaic module of claim 3, wherein, The connecting surface (42032) is inclined towards the radial direction of the welding wire (420), and the retreat-stop surface (42031) is parallel to the second end surface (4102) of the adhesive film layer (410). The adhesive film layer (410) includes a first adhesive film layer and a second adhesive film layer, the first adhesive film layer and the second adhesive film layer are connected, and the pre-crosslinking index of the first adhesive film layer is smaller than that of the second adhesive film layer.

5. The photovoltaic module of claim 1, wherein, The first adhesive film layer is configured to be connected with the back plate (500), and the second adhesive film layer is configured to be inserted into part of the welding wire (420). The outer periphery of the welding wire (420) is wrapped with a tin-lead-bismuth alloy layer.

6. The photovoltaic module of claim 1, wherein, The battery cell (300) is a back contact battery, and a back surface of the back contact battery is provided with a plurality of grid lines, the plurality of grid lines are arranged at equal intervals along a first direction, and the grid lines extend along a second direction, the welding wire (420) is connected with the grid lines, and the welding wire (420) extends along the first direction, and the first direction and the second direction are perpendicular to each other.

7. The photovoltaic module of claim 1, wherein, ​ 8. The photovoltaic module of claim 7, wherein, The welding wire (420) comprises a plurality of positive welding wires (4204) and a plurality of negative welding wires (4205), the positive welding wires (4204) and the negative welding wires (4205) are arranged alternately along the second direction; the back surface of the back contact battery is provided with a plurality of positive grid lines and a plurality of negative grid lines, the positive grid lines and the negative grid lines are arranged alternately along the second direction; The positive welding wire (4204) is connected with the positive grid line, and the negative welding wire (4205) is connected with the negative grid line.

9. The photovoltaic module of claim 8, wherein, A plurality of first partition positions (4103) and a plurality of second partition positions (4104) are arranged on the wire-penetrating adhesive film (400), the first partition positions (4103) and the second partition positions (4104) are arranged alternately along the second direction, the first partition positions (4103) are configured to partition the positive welding wire (4204), and the second partition positions (4104) are configured to partition the negative welding wire (4205).

10. The photovoltaic module of any of claims 1-9, wherein, The front glass (100), the front adhesive film (200), the battery unit (300), the wire-penetrating adhesive film (400) and the back plate (500) are sequentially laminated to form a laminated part, and the photovoltaic module further comprises a frame (600), and the frame (600) is arranged around the laminated part.

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