Method for manufacturing a photovoltaic module, photovoltaic module

Abstract

The embodiment of the present disclosure relates to the photovoltaic field, and provides a preparation method of a photovoltaic module, and the photovoltaic module. The preparation method comprises the following steps: providing at least two cell pieces and a plurality of welding strips; placing the welding strips on preset areas of the cell pieces, and the parts of the cell pieces located in the preset areas are provided with conductive parts; providing a pre-adhesion film, and the side of the pre-adhesion film facing the cell pieces is provided with a plurality of positioning grooves, and a single welding strip is at least corresponding to one positioning groove; covering the pre-adhesion film on the side of the welding strip away from the cell pieces, and at least part of the welding strip is accommodated in the positioning groove; providing a pressing plate, and setting the pressing plate on the side of the pre-adhesion film away from the cell pieces, so that the pre-adhesion film adheres the welding strips to the preset areas, and the plurality of cell pieces are connected into a to-be-welded cell string; and sending the to-be-welded cell string into a laminating stage, and the laminating temperature is greater than or equal to the melting point of the outer layer of the welding strip, so that the welding strip and the conductive part are alloyed. The embodiment of the present disclosure is at least beneficial to reducing the risk of cell piece warping while avoiding welding strip deviation.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the field of photovoltaics, and in particular to a method for manufacturing a photovoltaic module and a photovoltaic module. BACKGROUND

[0002] Currently, in the manufacturing process of a photovoltaic module, a solder strip and a cell are usually high-temperature welded by infrared or laser, and the solder strip and the electrode paste on the cell are alloyed by using instantaneous high temperature. However, due to the high welding temperature, the thermal expansion coefficients of different objects are different, so that the shrinkage of the solder strip is much larger than that of the cell. Since the solder strip and the cell are fixedly welded and cannot be displaced, the solder strip pulls the cell to form unilateral warping, and the cell is prone to cracking in subsequent processes.

[0003] In addition, before the solder strip and the electrode paste on the cell are alloyed, the solder strip is prone to shift on the cell, which makes the solder strip and the cell grid line not accurately positioned, and causes the solder strip and the cell to be virtually connected.

[0004] Therefore, the current manufacturing process of the photovoltaic module still needs to be improved. SUMMARY

[0005] Embodiments of the present disclosure provide a method for manufacturing a photovoltaic module and a photovoltaic module, which at least helps to avoid solder strip shift and reduce the risk of cell warping.

[0006] According to some embodiments of the present disclosure, in one aspect, a method for manufacturing a photovoltaic module is provided, which includes: providing at least two cells and a plurality of solder strips, and placing the solder strips on a preset area of the cells, a part of the cells located in the preset area having a conductive part; providing a pre-adhesion film, the pre-adhesion film having a plurality of positioning grooves on a side facing the cells, and each solder strip corresponding to at least one positioning groove; covering the pre-adhesion film on a side of the solder strips away from the cells, and at least part of the solder strips being accommodated in the positioning grooves; providing a pressing plate, and setting the pressing plate on a side of the pre-adhesion film away from the cells, and applying pressure to the pre-adhesion film through the pressing plate, so that the pre-adhesion film adheres the solder strips to the preset area, and a plurality of the cells are connected into a to-be-welded cell string; and sending the to-be-welded cell string to a lamination stage, the lamination temperature of the lamination stage being greater than or equal to the melting point of a material constituting an outer layer of the solder strip, so as to realize alloying of the solder strip and the conductive part.

[0007] In some embodiments, the positioning grooves are long strip-shaped grooves extending in a first direction, the positioning grooves correspond to the solder strips one by one, and the first direction is the extension direction of the solder strips.

[0008] In some embodiments, the conductive part is a pad, and each of the solder ribbons is opposite to a plurality of the pads arranged in a first direction in a second direction, the first direction being an extension direction of the solder ribbons, and the second direction being a thickness direction of the battery piece; the pre-bonding film comprises a body part and a positioning part, the positioning part being located on a side of the body part close to the battery piece, and the positioning part has the positioning groove therein, and the positioning groove and the pad are opposite to each other in the second direction.

[0009] In some embodiments, in a third direction perpendicular to the extension direction of the solder ribbons, a distance between the solder ribbons and the positioning groove is 0.1mm-0.3mm.

[0010] In some embodiments, a side of the pressing plate close to the pre-bonding film has a protruding part, and each of the protruding parts is opposite to at least one of the positioning grooves in the second direction, the second direction being the thickness direction of the battery piece.

[0011] In some embodiments, the protruding part is a strip-shaped protruding part extending in the first direction, and each of the protruding parts corresponds to one of the solder ribbons.

[0012] In some embodiments, a plurality of the protruding parts are arranged in the first direction and a third direction perpendicular to the extension direction of the solder ribbons, and each of the solder ribbons is opposite to a plurality of the positioning parts arranged in the first direction in the second direction.

[0013] In some embodiments, a material constituting an outer layer of the solder ribbons comprises tin, the laminating temperature is 140℃-170℃, and / or a duration of the laminating stage is 4min-5min.

[0014] In some embodiments, the preparation method further comprises: providing a bottom plate for bearing a side of the battery piece away from the solder ribbons, the bottom plate having a first heating part or the pressing plate having a second heating part; and in the step of applying pressure to the pre-bonding film by the pressing plate, the battery piece, the solder ribbons and the pre-bonding film are heated by the first heating part or the second heating part.

[0015] According to some embodiments of the present disclosure, another aspect of the present disclosure further provides a photovoltaic module formed by the preparation method of the photovoltaic module according to any one of the above.

[0016] The technical solutions provided by the embodiments of the present disclosure have at least the following advantages:

[0017] Firstly, the side of the pre-adhesion film facing the battery piece has a plurality of positioning grooves, and a single solder strip corresponds to at least one positioning groove. When the pre-adhesion film is subsequently covered on the side of the solder strip away from the battery piece, the positioning grooves are conducive to accommodating at least part of the solder strip. In other words, after the solder strip is placed in the preset area of the battery piece, not only the top surface of the solder strip is in contact with the pre-adhesion film, but also the two sides of the solder strip are in contact with the pre-adhesion film. Thus, during the subsequent lamination stage of applying force to the pre-adhesion film by the pressing plate, the pre-adhesion film on the two sides of the solder strip can not only effectively avoid the deviation of the solder strip, but also be adhered to the battery piece based on the pressure applied by the pressing plate. Therefore, the solder strip can be locked on the preset area by the adhesion of the pre-adhesion film and the battery piece, thereby ensuring that the solder strip is in contact with the conductive part on the preset area.

[0018] Secondly, before the alloying of the solder strip and the conductive part is realized, the solder strip is first adhered to the preset area of the battery piece in advance by the cooperation of the pre-adhesion film and the pressing plate, so as to ensure that the solder strip is in contact with the conductive part on the preset area and avoid the deviation of the solder strip during the subsequent lamination stage. Thus, the problem of virtual connection between the solder strip and the battery piece during the lamination stage can be avoided. In addition, based on the adhesion and pressing of the solder strip in advance, the deviation of the solder strip is avoided. On this basis, during the lamination stage, the solder strip and the conductive part can be alloyed only by the lamination temperature being greater than or equal to the melting point of the material constituting the outer layer of the solder strip, without the aid of instantaneous high-temperature welding. Thus, it is conducive to reducing the risk of warping of the battery piece by reducing the welding temperature. BRIEF DESCRIPTION OF DRAWINGS

[0019] One or more embodiments are illustrated by way of example in the drawings that are for illustrative purposes only, and not for the purposes of limiting the embodiments, unless otherwise explicitly stated in the specification. As is evident from the figures of the drawings, the drawings do not limit the scope of the embodiments. In the drawings:

[0020] Figure 1 A flowchart of a method for manufacturing a photovoltaic module according to an embodiment of the present disclosure is shown in FIG. 1.

[0021] Figure 2 A partial top view of a battery piece in a method for manufacturing a photovoltaic module according to an embodiment of the present disclosure is shown in FIG. 2.

[0022] Figure 3 Another partial top view of a battery piece in a method for manufacturing a photovoltaic module according to an embodiment of the present disclosure is shown in FIG. 3.

[0023] Figure 4 A partial cross-sectional structure schematic diagram of a soldering ribbon in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0024] Figure 5 A partial upside-down structure schematic diagram of a pre-adhesion film in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0025] Figure 6 A first partial cross-sectional structure schematic diagram of a pre-adhesion film not adhered to a soldering ribbon and a cell in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0026] Figure 7 A second partial cross-sectional structure schematic diagram of a pre-adhesion film not adhered to a soldering ribbon and a cell in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0027] Figure 8 Another partial upside-down structure schematic diagram of a pre-adhesion film in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0028] Figure 9 A third partial cross-sectional structure schematic diagram of a pre-adhesion film not adhered to a soldering ribbon and a cell in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0029] Figure 10 A first partial cross-sectional structure schematic diagram of a pressing plate not pressed onto a pre-adhesion film in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0030] Figure 11 A second partial cross-sectional structure schematic diagram of a pressing plate not pressed onto a pre-adhesion film in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0031] Figure 12 A third partial cross-sectional structure schematic diagram of a pressing plate not pressed onto a pre-adhesion film in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0032] Figure 13 A partial upside-down structure schematic diagram of a pressing plate in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0033] Figure 14 Another partial upside-down structure schematic diagram of a pressing plate in a preparation method of a photovoltaic module according to an embodiment of the present disclosure is provided;

[0034] Figure 15 A partial three-dimensional structure schematic diagram of a photovoltaic module according to another embodiment of the present disclosure is provided;

[0035] Figure 16 A partial three-dimensional structure schematic diagram of a photovoltaic module according to another embodiment of the present disclosure is provided; Figure 15A schematic view of a partial cross-sectional structure along a first cross-sectional direction AA1.

[0036] Figure 17 For Figure 15 A schematic view of a partial cross-sectional structure along a second cross-sectional direction BB1. DETAILED DESCRIPTION

[0037] As known from the background art, the preparation process of the photovoltaic module still needs to be improved to improve the warping risk of the cell sheet and the virtual connection problem of the solder strip and the cell sheet.

[0038] The present disclosure provides a preparation method of a photovoltaic module and a photovoltaic module. In the preparation method, first, a pre-adhesion film is designed to have a plurality of positioning grooves on the side facing the cell sheet, and a single solder strip corresponds to at least one positioning groove. When the pre-adhesion film is subsequently covered on the side of the solder strip away from the cell sheet, it is beneficial to make the positioning groove accommodate at least part of the solder strip, so that not only the top surface of the solder strip is in contact and connected with the pre-adhesion film, but also the two sides of the solder strip are in contact and connected with the pre-adhesion film. In this way, during the subsequent pressing of the pre-adhesion film by the pressing plate and the lamination stage, the pre-adhesion film located on both sides of the solder strip can also be adhered to the cell sheet based on the pressure applied by the pressing plate, so as to lock the solder strip on the pre-set area and ensure that the solder strip is in contact and connected with the conductive part on the pre-set area. Secondly, before the alloying of the solder strip and the conductive part is realized, the solder strip is first adhered on the pre-set area of the cell sheet by the cooperation of the pre-adhesion film and the pressing plate, so as to avoid the subsequent offset of the solder strip relative to the cell sheet during the lamination stage. On this basis, the lamination stage does not need to rely on the instantaneous high-temperature welding, but only needs the lamination temperature of the lamination stage to be greater than or equal to the melting point of the material constituting the outer layer of the solder strip, so as to realize the alloying of the solder strip and the conductive part, thereby being beneficial to reducing the warping risk of the cell sheet by reducing the welding temperature.

[0039] In the description of the embodiments of the present disclosure, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0040] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present disclosure. The occurrence of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of the associated objects, that is, there can be three relationships, for example, A and / or B, which can represent: there is A, there is A and B, and there is B. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0042] In the description of the embodiments of the present disclosure, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0043] In the description of the embodiments of the present disclosure, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present disclosure.

[0044] In the description of the embodiments of the present disclosure, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0045] In the corresponding drawings of the embodiments of the present disclosure, in order to better understand and facilitate the description, the thickness and area of the layer are enlarged. When describing that a component (such as a layer, a film, a region or a substrate) is on or on the surface of another component, the component can be "directly" on the surface of the other component, or there can be a third component between the two components. On the contrary, when describing that a component is on the surface of another component or a component surface is formed or provided with another component, it means that there is no third component between the two components. In addition, when describing that a component is "formed" on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on the edge of the entire surface.

[0046] In the description of the embodiments of the present disclosure, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components can be further included. In addition, when a layer, film, region, plate, or the like is referred to as "on" or "under" another component, it can be "directly on" or "under" the other component (i.e., between the other component and the layer, film, region, plate, or the like, no other component is present). In addition, when a layer, film, region, plate, or the like is "directly on" another component, or when a layer, film, region, plate, or the like is on the surface of another component, it means that no other component is present therebetween.

[0047] The terms used in the description of various described embodiments herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of various embodiments described and the appended claims, "the component" is also intended to include a plurality of components, unless the context clearly indicates otherwise. Among them, the components include layers, films, regions, or plates and the like.

[0048] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. However, those skilled in the art can understand that in the embodiments of the present disclosure, many technical details are presented in order to enable the reader to better understand the embodiments of the present disclosure. However, the technical solutions claimed by the embodiments of the present disclosure can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0049] An embodiment of the present disclosure provides a preparation method of a photovoltaic module, which will be described in detail below with reference to the accompanying drawings.

[0050] Reference Figures 1 to 14 , Figure 1 A flowchart of the preparation method of the photovoltaic module provided by an embodiment of the present disclosure is shown in the following figure, Figures 2 to 14 The preparation method of the photovoltaic module at least includes the following steps, which will be described in detail below.

[0051] S1: Provide at least two cell pieces 100 and a plurality of solder strips 101, and place the solder strip 101 on the preset area 110 of the cell piece 100, and the part of the cell piece 100 located in the preset area 110 has a conductive part 120.

[0052] S2: Provide a pre-adhesion film 102, and the side of the pre-adhesion film 102 facing the cell piece 100 has a plurality of positioning grooves 112, and a single solder strip 101 corresponds to at least one positioning groove 112.

[0053] S3: Cover the pre-adhesion film 102 on the side of the solder strip 101 away from the cell piece 100, and at least part of the solder strip 101 is contained in the positioning groove 112.

[0054]

[0054] S4: providing a pressing plate 103, setting the pressing plate 103 on the side of the pre-bonding film 102 away from the battery sheet 100, and applying pressure to the pre-bonding film 102 through the pressing plate 103, so that the pre-bonding film 102 bonds the welding strip 101 on the preset area 110, and the plurality of battery sheets 100 are connected into the to-be-welded battery string.

[0055] S5: sending the to-be-welded battery string into a lamination stage, the lamination temperature of the lamination stage is greater than or equal to the melting point of the material constituting the outer layer 111 of the welding strip 101, so as to realize the alloying of the welding strip 101 and the conductive part 120.

[0056] It is worth noting that before the alloying of the welding strip 101 and the conductive part 120 is realized through step S5, steps S2 to S4 are designed to use the cooperation of the pre-bonding film 102 and the pressing plate 103 to bond the welding strip 101 on the preset area 110 of the battery sheet 100 in advance, so as to ensure that the welding strip 101 is in contact with the conductive part 120 on the preset area 110, and avoid the offset of the welding strip 101 relative to the battery sheet 100 in the subsequent lamination stage, i.e., step S5, for example, avoid the offset of the welding strip 101 to not contact the conductive part 120, so as to avoid the problem that the welding strip 101 cannot be alloyed and welded with the conductive part 120 in the lamination stage, i.e., the virtual connection problem of the welding strip 101 and the battery sheet 100.

[0057] Further, in step S2, the side of the pre-bonding film 102 facing the battery sheet 100 has a plurality of positioning grooves 112, and a single welding strip 101 corresponds to at least one positioning groove 112, which is beneficial to make the positioning groove 112 accommodate at least part of the welding strip 101 in step S3, that is, the welding strip 101 is clamped by the positioning groove 112, in other words, after the welding strip 101 is placed on the preset area 110 of the battery sheet 100, not only the top surface of the welding strip 101 is in contact with the pre-bonding film 102, but also the two sides of the welding strip 101 are in contact with the pre-bonding film 102. In this way, in step S4, the pre-bonding film 102 on both sides of the welding strip 101 can not only effectively avoid the offset of the welding strip 101, but also be bonded with the battery sheet 100 based on the pressure applied by the pressing plate 103, so that the welding strip 101 can be locked on the preset area 110 by the bonding of the pre-bonding film 102 and the battery sheet 100, and the welding strip 101 is in contact with the conductive part 120 on the preset area 110.

[0058] In addition, based on the bonding and pressing process of the welding strip 101 in steps S2 to S4, the offset of the welding strip 101 is avoided, and the contact connection between the welding strip 101 and the conductive part 120 on the preset area 110 is ensured. On this basis, in the lamination stage, i.e. step S5, without the help of instantaneous high-temperature welding, only the lamination temperature of the lamination stage is greater than or equal to the melting point of the material constituting the outer layer 111 of the welding strip 101, the alloying of the welding strip 101 and the conductive part 120 can be realized to weld the welding strip 101 on the battery piece 100, thereby facilitating the reduction of the risk of warping of the battery piece 100 by reducing the welding temperature.

[0059] It should be noted that, in order to show the preset area 110 on the battery piece 100, Figure 1 the preset area 110 on the battery piece 100 is divided by a dashed line in the embodiment.

[0060] The steps in the preparation method of the photovoltaic module provided by the embodiment of the present disclosure will be described in more detail below in combination with the drawings.

[0061] The conductive part 120 on the part of the battery piece 100 provided in step S1 has at least the following two embodiments.

[0062] In some embodiments, referring to Figure 2 , Figure 2 The partial top view structure diagram of the battery piece in the preparation method of the photovoltaic module provided by the embodiment of the present disclosure is shown, and the battery piece 100 is a BC battery (Back Contact, back contact battery) without main grid. Based on this, the conductive part 120 on the part of the battery piece 100 located in the preset area 110 can be a solder pad 120a for welding with the welding strip 101.

[0063] In some other embodiments, referring to Figure 3 , Figure 3 The partial top view structure diagram of the battery piece in the preparation method of the photovoltaic module provided by the embodiment of the present disclosure is shown, and the battery piece 100 is a battery piece with main grid, and the conductive part 120 on the part of the battery piece 100 located in the preset area 110 can be a main grid 120b for welding with the welding strip 101. In some examples, the battery piece with main grid includes but is not limited to one of a BC battery (Back Contact, back contact battery), a PERC battery (Passivated Emitter Rear Cell, emitter and back surface passivated cell), a TOPCon battery (Tunnel Oxide Passivated Contact, tunnel oxide passivated contact cell), or a HIT / HJT battery (Heterojunction Technology, heterojunction battery).

[0064] In the above two embodiments, the BC battery includes an IBC battery (Interdigitated Back Contact), an HBC battery (Heterojunction Back Contact), a TBC battery (TOPCon Back Contact), an HPBC battery (Hybrid Passivated Back Contact), or the like.

[0065] In some embodiments, with reference to Figure 4 , Figure 4 A partial cross-sectional structure schematic diagram of a solder strip in a preparation method of a photovoltaic module provided by an embodiment of the present disclosure is shown in FIG. 1. The material constituting the outer layer 111 of the solder strip 101 includes tin, and the lamination temperature is 140-170°C. For example, the lamination temperature can be 143°C, 145°C, 148°C, 150°C, 152°C, 155°C, 157°C, 160°C, 162°C, 165°C, or 168°C, etc.

[0066] It is worth noting that step S5, i.e., the lamination stage, is to realize the alloying of the solder strip 101 and the conductive part 120. Compared with high-temperature welding by infrared or laser, the lamination temperature in the lamination stage is lower, and only needs to be greater than or equal to the melting point of the material constituting the outer layer 111 of the solder strip 101. Moreover, the solder strip used in step S5 is different from the solder strip used in high-temperature welding by infrared or laser. The melting point of the outer layer material of the solder strip used in high-temperature welding by infrared or laser is generally higher than 180°C, but the melting point of the outer layer of the solder strip used in step S5 is lower, which is conducive to further reducing the lamination temperature in the lamination stage, so that the lamination temperature is 140-170°C, thereby being conducive to reducing the warping risk of the battery piece 100 by reducing the welding temperature.

[0067] In some embodiments, the duration of the lamination stage can be 4-5 min. For example, the duration of the lamination stage can be 245 s, 250 s, 255 s, 260 s, 265 s, 270 s, 275 s, 280 s, 285 s, 290 s, or 295 s, etc. In this way, in the case that the lamination temperature in the lamination stage is low, it is conducive to fully alloying the solder strip 101 and the conductive part 120 on the battery piece 100 by a longer and slower lamination time, so as to further improve the welding efficiency between the solder strip 101 and the conductive part 120, thereby being conducive to improving the yield of the photovoltaic module finally formed.

[0068] In some cases, the solder strip 101 also includes an inner layer 121 wrapped by the outer layer 111. In some examples, the materials of the outer layer 111 and the inner layer 121 may be different, and the material of the inner layer 121 may be a conductive material such as copper, silver, or aluminum; in other examples, the materials of the outer layer and the inner layer may be the same.

[0069] It should be noted that, in order to illustrate the outer layer 111 and inner layer 121 in solder strip 101, Figure 4 The outer layer 111 and the inner layer 121 are divided by dashed lines; in addition, Figure 4 The example only uses a circular cross-sectional shape for the solder strip 101. In practical applications, the cross-sectional shape of the solder strip can also be rectangular or triangular, etc. This embodiment of the present disclosure does not limit the cross-sectional shape of the solder strip. For the convenience of explaining the positioning groove 112, the pre-adhesive film 102 is shown as having a circular cross-sectional shape for the solder strip 101 in the following figures.

[0070] The following describes in detail the case where a single solder strip 101 corresponds to at least one positioning groove 112 in the pre-adhesive film 102.

[0071] In some embodiments, in conjunction with reference Figure 5 and Figure 6 or refer to Figure 7 The positioning groove 112 can be an elongated groove extending along the first direction X. The positioning groove 112 corresponds one-to-one with the solder ribbon 101, and the first direction X is the extension direction of the solder ribbon 101. In this way, after the pre-adhesive film 102 is covered on the solder ribbon 101 in step S3, one positioning groove 112 engages with one solder ribbon 101, which can quickly fix the solder ribbon 101 on the preset area 110 of the battery cell 100 and prevent the solder ribbon 101 from shifting relative to the battery cell 100.

[0072] in, Figure 5 This is a schematic diagram of a partial overhead structure of the pre-bonded film in a photovoltaic module fabrication method according to an embodiment of this disclosure. Figure 6 This is a schematic diagram of a first partial cross-sectional structure in a photovoltaic module manufacturing method provided in an embodiment of the present disclosure, in which the pre-bonding film is not bonded to the solder ribbon and the solar cell. Figure 7 This is a schematic diagram of a second partial cross-sectional structure in a photovoltaic module manufacturing method provided in an embodiment of the present disclosure, in which the pre-bonding film is not bonded to the solder ribbon and the battery cell.

[0073] In some cases, the length of the positioning groove 112 along the first direction X is greater than or equal to the length of the battery cell 100. In other words, the positioning groove 112 penetrates the pre-adhesive film 102 along the first direction X, so that a single positioning groove 112 can accommodate the entire welding strip 101 located on the battery cell 100, which also helps to reduce the risk of the welding strip 101 bending due to external force.

[0074] In some examples, in conjunction with references Figure 5 and Figure 6 The positioning groove 112, which is a long strip-shaped groove, is embedded in the pre-adhesive film 102. In other words, along the second direction Y, the thickness of the part of the pre-adhesive film 102 that is directly opposite to the solder ribbon 101 is less than the thickness of the part of the pre-adhesive film 102 that is not directly opposite to the solder ribbon 101.

[0075] In other examples, refer to Figure 7 The pre-adhesive film 102 includes a film body 142 and a positioning strip 152. The positioning strip 152 extends along the first direction X and is located on the side of the film body 142 near the solar cell 100. A positioning groove 112, which is an elongated groove, is embedded in the positioning strip 152. In other words, different parts of the positioning strip 152 have different thicknesses in the second direction Y to form the positioning groove 112 in the positioning strip 152. The thickness of the film body 142 is less than the average thickness of the positioning strip 152. This is beneficial for fixing the solder ribbon 101 to the preset area 110 in advance with the pre-adhesive film 102, while reducing the amount of adhesive required for the pre-adhesive film 102 as a whole, thereby reducing the manufacturing cost of the photovoltaic module.

[0076] It should be noted that, Figure 7 The membrane body 142 and the positioning strip 152 are divided on the pre-bonded membrane 102 by dashed lines.

[0077] In other embodiments, reference is made to... Figure 2 The conductive portion 120 is a pad 120a. A single solder strip 101 is directly opposite to a plurality of pads 120a spaced apart along a first direction X along a second direction Y. The first direction X is the extension direction of the solder strip 101, and the second direction Y is the thickness direction of the solar cell 100. (Refer to reference) Figure 2 , Figure 8 and Figure 9 The pre-bonded film 102 includes a body portion 122 and a positioning portion 132. The positioning portion 132 is located on the side of the body portion 122 close to the battery cell 100, and the positioning portion 132 has a positioning groove 112. The positioning groove 112 and the pad 120a are directly opposite each other along the second direction Y.

[0078] in, Figure 8 This is a schematic diagram of another partial overhead structure of the pre-bonded film in the photovoltaic module fabrication method provided in an embodiment of this disclosure. Figure 9 This is a schematic diagram of a third partial cross-sectional structure in the photovoltaic module fabrication method provided in an embodiment of this disclosure, where the pre-bonding film is not bonded to the solder ribbon and the solar cell. It should be noted that... Figure 9 The body portion 122 and the positioning portion 132 are divided on the pre-adhesive film 102 by dashed lines.

[0079] It is worth noting that the pre-bonding film 102 has multiple positioning grooves 112 spaced apart along the first direction X, and also multiple positioning grooves 112 spaced apart along the arrangement direction of the multiple solder strips 101. This is beneficial because each solder strip 101 can correspond to multiple positioning grooves 112. Moreover, if the location where each positioning groove 112 corresponds to the solder strip 101 is regarded as a positioning point, then each solder strip 101 is designed with multiple positioning points. The positioning grooves 112 and the pads 120a are designed to be directly aligned along the second direction Y. This ensures that the multiple positioning points on each solder strip 101 are directly aligned with the pads 120a along the second direction Y. This is beneficial because it helps to prevent the solder strip 101 from being bent by external forces, and also allows for more precise contact and connection between the solder strip 101 and the multiple pads 120a, effectively preventing the phenomenon of misalignment between the solder strip 101 and the pads 120a.

[0080] Furthermore, relative to the main body 122, the positioning portion 132 protrudes towards the direction close to the solar cell 100. Different portions of the positioning portion 132 have different thicknesses in the second direction Y, forming a positioning groove 112 in the positioning portion 132. The thickness of the film body 142 is less than the average thickness of the positioning portion 132. In other words, by designing the positioning portion 132 only in the area on the pre-adhesive film 102 that is directly opposite the pad 120a along the second direction Y, it is advantageous to further reduce the amount of adhesive required for the pre-adhesive film 102 while pre-fixing the solder ribbon 101 to the preset area 110 using the pre-adhesive film 102, thereby further reducing the manufacturing cost of the photovoltaic module.

[0081] It should be noted that regardless of whether the solar cell 100 is a grid-less cell or a cell with a grid, the conductive part 120 can be a pad 120a. However, the size of the pads in a grid-less cell is smaller than that in a cell with a grid, and the number of pads in a grid-less cell is greater than that in a cell with a grid. Furthermore, Figure 3 The pads that make electrical contact with the main gate 120b are not shown in the diagram.

[0082] In some embodiments, reference Figure 6 , Figure 7 or Figure 9 Along the third direction Z, the distance between the solder strip 101 and the positioning groove 112 can be 0.1mm to 0.3mm, and the third direction Z is perpendicular to the extension direction of the solder strip 101. For example, the distance between the solder strip 101 and the positioning groove 112 can be 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.23mm, 0.25mm, 0.26mm, or 0.28mm, etc.

[0083] In some cases, refer to Figure 6 , Figure 7 or Figure 9The welding strip 101 can be a round welding strip, that is, the cross-sectional shape of the welding strip 101 in the section perpendicular to the first direction X is circular or elliptical, etc., and the width of the round welding strip in the third direction Z is 0.2mm to 0.4mm, for example, 0.23mm, 0.25mm, 0.26mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.36mm or 0.39mm, etc.

[0084] In other cases, the welding strip can be a flat welding strip, and the cross-sectional shape of the welding strip in the section perpendicular to the first direction is rectangular or rectangular with rounded corners, etc. The width of the flat welding strip in the third direction is 0.4mm to 2mm, for example, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm or 1.9mm, etc.

[0085] In some embodiments, reference Figure 10 or Figure 11 The pressure plate 103 has a protrusion 113 on the side facing the pre-adhesive film 102. Each protrusion 113 is directly opposite to at least one positioning groove 112 along the second direction Y, which is the thickness direction of the battery cell 100.

[0086] Thus, with each protrusion 113 facing at least one solder ribbon 101 along the second direction Y, during step S4 when pressure is applied to the pre-adhesive film 102 by the pressure plate 103, the pressure applied by the protrusion 113 to the pre-adhesive film 102 is greater than the pressure applied by the portion of the pressure plate 103 without the protrusion 113. This helps to further ensure that the solder ribbon 101 and the preset area 110 of the battery cell 100 are tightly bonded. Specifically, on the one hand, the pressure applied to the pre-adhesive film 102 by the pressure plate 103 causes the pre-adhesive film 102 on both sides of the solder ribbon 101 to bond with the battery cell 100, effectively preventing the solder ribbon 101 from shifting left and right; on the other hand, the greater pressure applied by the protrusion 113 to the pre-adhesive film 102 increases the friction between the solder ribbon 101 and the battery cell 100, further preventing the solder ribbon 101 from shifting left and right, and also helping to strengthen the connection strength between the solder ribbon 101 and the conductive part 120.

[0087] in, Figure 10 This is a schematic diagram of a first partial cross-sectional structure in a photovoltaic module manufacturing method provided in an embodiment of the present disclosure, where the pressure plate is not pressed onto the pre-adhesive film. Figure 11 This is a schematic diagram of a second partial cross-sectional structure in a photovoltaic module manufacturing method provided in an embodiment of the present disclosure, in which the pressure plate is not pressed onto the pre-adhesive film.

[0088] In some examples, refer toFigure 10 or Figure 11 The pressure plate 103 also has a pressure plate body 123, which is located on the side of the protrusion 113 away from the battery cell 100. The protrusion 113 is movably mounted on the pressure plate body 123. It should be noted that... Figure 10 and Figure 11 The protrusion 113 and the body 123 of the pressure plate 103 are separated by solid lines.

[0089] It is worth noting that the number of solder ribbons 101 designed on the solar cell 100 and the position of the solder ribbons 101 on the solar cell 100 are different for different sizes and specifications of solar cells 100. Based on this, the protrusion 113 is designed to be movably installed on the pressure plate body 123, so that the pressure plate 103 can be used for solar cells 100 of various sizes and specifications, which is beneficial to improving the versatility of the pressure plate 103 and reducing the manufacturing cost of photovoltaic modules.

[0090] In some cases, by setting corresponding programs in automated equipment, the protrusions 113 on the pressure plate 103 can be moved to a position directly opposite the solder strips 101 on the cell to be pressed along the second direction Y. This helps to avoid human error caused by manual operation of the protrusions 113 and reduces labor costs in the photovoltaic module manufacturing process. Moreover, a mapping table of cell and solder strip positions of different sizes can be pre-stored in the automated equipment, which facilitates the rapid movement of the protrusions 113 on the pressure plate 103 to a position directly opposite the solder strips 101 on the cell to be pressed along the second direction Y, thereby improving the manufacturing efficiency of photovoltaic modules.

[0091] In some examples, refer to Figure 12 , Figure 12 This is a schematic diagram of a third partial cross-sectional structure of a photovoltaic module manufacturing method provided in an embodiment of the present disclosure, in which the pressure plate is not pressed onto the pre-bonding film. The protrusion 113 is a first pressure needle 113a. The side of the pressure plate 103 facing the pre-bonding film 102 also has a second pressure needle 133. The first pressure needle 113a is provided with the second pressure needle 133 on opposite sides along the third direction Z. The third direction Z is perpendicular to the extension direction of the solder strip 101, and the second pressure needle 133 and the solder strip 101 are not directly opposite each other along the second direction Y. The pressing depth of the second pressure needle 133 is greater than the pressing depth of the first pressure needle 113a.

[0092] Thus, on the one hand, the friction between the solder ribbon 101 and the battery cell 100 can be increased by the first pressure needle 113a, further preventing the solder ribbon 101 from shifting left and right, and also helping to strengthen the connection strength between the solder ribbon 101 and the conductive part 120; on the other hand, the pressure applied to the pre-adhesive films 102 on the left and right sides of the solder ribbon 101 along the second direction Y can be increased by the second pressure needle 133, further improving the bonding effect between the pre-adhesive films 102 on both sides of the solder ribbon 101 and the battery cell 100, thereby improving the blocking effect of the pre-adhesive films 102 on both sides of the solder ribbon 101 on the solder ribbon 101, and further ensuring that the solder ribbon 101 does not shift.

[0093] In addition, the pressing depth of the second pressing needle 133 is designed to be greater than that of the first pressing needle 113a, which can compensate for the height difference between the pressing plate body 123 and the protrusion 113 to a certain extent. This ensures that the second pressing needle 133 applies greater pressure to the pre-bonding film 102 located on the left and right sides of the welding ribbon 101, so as to ensure a good bonding effect between the pre-bonding film 102 located on the left and right sides of the welding ribbon 101 and the battery cell 100.

[0094] In some cases, at least one of the first pressure needle 113a and the second pressure needle 133 may have a heating function. During the process of applying pressure to the pre-bonded film 102 through the pressure plate 103 in step S4, the pre-bonded film 102 can be pre-melted under the dual action of pressure and heating, thereby improving the deformability and adhesion of the pre-bonded film 102. This facilitates the bonding and adhesion of the inner wall of the positioning groove 112 formed on the pre-bonded film 102 to the welding ribbon 101, and also allows the pre-bonded film 102 in other areas to be bonded and adhered to the battery cell 100. Based on the all-round wrapping of the welding ribbon 101 by the pre-bonded film 102 and the battery cell 100, the displacement of the welding ribbon 101 is avoided, and the internal stability of the multiple battery cells 100 connected to form a battery string to be welded is improved.

[0095] The following describes in detail the case where a single protrusion 113 is directly opposite to at least one positioning groove 112 along the second direction Y.

[0096] In some embodiments, reference Figure 13 , Figure 13 This is a partial overhead structure diagram of the pressure plate in a photovoltaic module fabrication method according to an embodiment of the present disclosure. The protrusion 113 can be an elongated protrusion extending along the first direction X, and the protrusion 113 corresponds one-to-one with the solder ribbon 101. Thus, after applying pressure to the pre-bonding film 102 by the pressure plate 103 in step S4, one protrusion 113 and one solder ribbon 101 are directly opposite each other along the second direction Y, so as to increase the pressure applied to the solder ribbon 101, thereby increasing the friction between the solder ribbon 101 and the cell 100, further preventing the solder ribbon 101 from shifting left and right, and also helping to strengthen the connection strength between the solder ribbon 101 and the conductive part 120.

[0097] In some cases, the length of the elongated protrusion 113 along the first direction X is greater than or equal to the length of the battery cell 100, so that a single protrusion 113 can be directly aligned with the entire welding strip 101 on the battery cell 100 along the second direction Y. This helps to ensure that the welding strip 101 is subjected to uniform force at various parts along the first direction X, thereby reducing the risk of the welding strip 101 bending due to external forces.

[0098] In some examples, in conjunction with references Figure 6 and Figure 13 Or, in conjunction with references Figure 7 and Figure 13 The positioning groove 112 is an elongated groove extending along the first direction X, and the positioning groove 112 corresponds one-to-one with the welding strip 101. Since the elongated protrusions 113 also correspond one-to-one with the welding strip 101, after the pressure is applied to the pre-adhesive film 102 by the pressure plate 103 in step S4, the protrusions 113 and the positioning grooves 112 are directly aligned along the second direction Y. Based on this, in step S4, the elongated protrusions 113 can cause the pre-adhesive film 102 located on the top side of the welding strip 101 to be squeezed to the left and right sides of the welding strip 101, so that the pre-adhesive film 102 located on the left and right sides of the welding strip 101 is pressed downward and tightly adhered to the battery cell 100 under the dual action of the pressure and extrusion force applied by the pressure plate 103, thereby improving the bonding strength between the pre-adhesive film 102 and the battery cell 100.

[0099] In other examples, in conjunction with references Figure 9 and Figure 13 The pre-bonding film 102 includes a body portion 122 and a positioning portion 132. The positioning portion 132 is located on the side of the body portion 122 near the battery cell 100, and the positioning portion 132 has a positioning groove 112. The positioning groove 112 and the solder pad 120a are directly opposite each other along the second direction Y. Since the elongated protrusions 113 correspond one-to-one with the solder strips 101, after pressure is applied to the pre-bonding film 102 by the pressure plate 103 in step S4, each protrusion 113 and the plurality of positioning grooves 112 corresponding to each solder strip 101 are directly opposite each other along the second direction Y.

[0100] Based on this, in step S4, the elongated protrusion 113 can at least exert greater pressure on the outer contour of the positioning groove 112 in the positioning part 132, and further squeeze it to the left and right sides of the solder ribbon 101. This causes the pre-adhesive film 102 located on the left and right sides of the solder ribbon 101 to adhere tightly to the battery cell 100 under the combined action of the pressure and extrusion force applied by the pressure plate 103, thereby improving the bonding strength between the pre-adhesive film 102 and the battery cell 100. Moreover, the positioning groove 112 and the solder pad 120a are directly opposite each other along the second direction Y. The individual elongated protrusion 113 can be directly opposite to the multiple solder pads 120a corresponding to the individual solder ribbon 101 along the second direction Y, which also helps to make the solder ribbon 101 and the solder pad 120a adhere more tightly.

[0101] In other embodiments, in conjunction with reference to Figure 9 and Figure 14 , Figure 14 This is a schematic diagram of another partial overhead structure of the pressure plate in the photovoltaic module manufacturing method provided in an embodiment of the present disclosure. Multiple protrusions 113 are arranged in an array along the first direction X and the third direction Z, with the third direction Z perpendicular to the extension direction of the solder strip 101. A single solder strip 101 is directly opposite to multiple positioning portions 132 arranged at intervals along the first direction X along the second direction Y.

[0102] It is worth noting that, in conjunction with references Figure 2 , Figure 9 and Figure 14 Each solder ribbon 101 is in contact with a plurality of conductive portions 120 spaced apart along the first direction X. A portion of the solder ribbon 101 does not need to be directly aligned with the conductive portions 120 along the second direction Y. Generally, to ensure the performance of the final photovoltaic module, the portion of the solder ribbon 101 not directly aligned with the conductive portions 120 along the second direction Y typically has an insulating layer between it and the solar cell 100. Based on this, the design of each solder ribbon 101 being directly aligned with a plurality of positioning portions 132 spaced apart along the first direction X along the second direction Y allows for greater pressure to be applied to the portion of the solder ribbon 101 directly aligned with the conductive portions 120 along the second direction Y using the protrusions 113, ensuring contact between the solder ribbon 101 and the conductive portions 120. Alternatively, the pressure applied by the pressure plate 103 to the portion of the solder ribbon 101 not directly aligned with the conductive portions 120 along the second direction Y can be appropriately reduced to avoid damage to the insulating layer, thereby ensuring good electrical performance of the final photovoltaic module.

[0103] In some examples, the conductive portion 120 is a pad 120a, and a single solder ribbon 101 is directly opposite to a plurality of pads 120a spaced apart along the first direction X along the second direction Y. The protrusion 113 is also directly opposite to the pads 120a along the second direction Y. Thus, each protrusion 113 can specifically press the solder ribbon 101 onto the pad 120a, resulting in better pressure from the pressure plate 103 on the solder ribbon 101 and the battery cell 100, and improving the alignment accuracy between the solder ribbon 101 and the pad 120a.

[0104] In some embodiments, step S4, in which pressure is applied to the pre-bonded film 102 by the pressure plate 103, may also include a heating process, which will be described in detail below.

[0105] In some embodiments, reference Figures 10 to 12 The method for manufacturing photovoltaic modules may further include: providing a base plate (not shown in the figure), the base plate being used to support the side of the cell 100 away from the solder ribbon 101, the base plate having a first heating part (not shown in the figure); in the step of applying pressure to the pre-bonded film 102 by the pressure plate 103, the cell 100, the solder ribbon 101 and the pre-bonded film 102 are heated by the first heating part.

[0106] Thus, after the welding strip 101 is engaged by the positioning groove 112, while applying greater pressure to the positioning groove 112 through the pressure plate 103, the pre-bonding film 102 is also heated by the first heating part. Under the dual action of pressure and heating, the pre-bonding film 102 is pre-melted, improving its deformability and adhesion. This facilitates the bonding and adhesion of the inner wall of the positioning groove 112 formed on the pre-bonding film 102 to the welding strip 101, and also allows the pre-bonding film 102 in other areas to bond and adhere to the battery cell 100. Based on the all-round wrapping of the welding strip 101 by the pre-bonding film 102 and the battery cell 100, the displacement of the welding strip 101 is avoided, and the internal stability of the multiple battery cells 100 connected to form a battery string to be welded is improved.

[0107] In some examples, the heating temperature of the first heating section on the battery cell 100 can be 70°C to 130°C, for example, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C or 125°C.

[0108] In other embodiments, reference is made to... Figures 10 to 12 The method for preparing a photovoltaic module may further include: a pressure plate 103 having a second heating section; in the step of applying pressure to the pre-bonding film 102 through the pressure plate 103, the cell 100, the solder ribbon 101 and the pre-bonding film 102 are heated by the second heating section.

[0109] It is worth noting that the second heating part can be at least one of the first or second pressure needles described in the foregoing embodiments, or it can be an additional component in the pressure plate 103 that is different from the first or second pressure needle.

[0110] In some examples, the heating temperature of the second heating section on the battery cell 100 can be 70°C to 130°C, for example, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C or 125°C.

[0111] In some embodiments, after the polarization step S5, i.e., the lamination stage, the battery strings to be welded have been completed into battery strings. The method for manufacturing photovoltaic modules may further include: assembling multiple battery strings in sequence with components such as encapsulant film, busbars, junction boxes, and cover plates to form a photovoltaic module. It should be noted that this embodiment of the present disclosure does not impose too many restrictions on the step of assembling multiple battery strings in sequence with components such as encapsulant film, busbars, junction boxes, and cover plates, and this can be achieved by various known technical means.

[0112] In summary, the pre-adhesive film 102 is designed with multiple positioning grooves 112 on the side facing the battery cell 100, and each solder ribbon 101 corresponds to at least one positioning groove 112. When the pre-adhesive film 102 is subsequently covered on the side of the solder ribbon 101 away from the battery cell 100, it facilitates the positioning grooves 112 to accommodate at least a portion of the solder ribbon 101. This ensures that not only the top surface of the solder ribbon 101 contacts the pre-adhesive film 102, but also both sides of the solder ribbon 101 contact the pre-adhesive film 102. Thus, during the subsequent pressure application and lamination stages using the pressure plate 103, the pre-adhesive film 102 on both sides of the solder ribbon 101 can also bond to the battery cell 100 based on the pressure applied by the pressure plate 103, locking the solder ribbon 101 onto the preset area 110 and ensuring contact between the solder ribbon 101 and the conductive portion 120 on the preset area 110. Secondly, before alloying the solder ribbon 101 and the conductive part 120, the solder ribbon 101 is pre-bonded to the preset area 110 of the cell 100 by the cooperation of the pre-bonding film 102 and the pressure plate 103. This prevents the solder ribbon 101 from shifting relative to the cell 100 during the subsequent lamination stage. Based on this, the lamination stage does not require instantaneous high-temperature welding. As long as the lamination temperature is greater than or equal to the melting point of the material constituting the outer layer 111 of the solder ribbon 101, the alloying of the solder ribbon 101 and the conductive part 120 can be achieved. This helps to reduce the risk of warping of the cell 100 by lowering the welding temperature.

[0113] Another embodiment of this disclosure provides a photovoltaic module, formed by the fabrication method of the photovoltaic module provided in the foregoing embodiments. The photovoltaic module provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that parts that are the same as or corresponding to those in the foregoing embodiments will not be repeated here.

[0114] Photovoltaic modules include those formed by the method for preparing photovoltaic modules as provided in the foregoing embodiments.

[0115] In some embodiments, in conjunction with reference Figure 1 , Figures 15 to 17 A photovoltaic module may include: a battery string, formed by steps S1 to S5 of the photovoltaic module preparation method provided in the foregoing embodiments; an encapsulating film 41 for covering the surface of the battery string; and a cover plate 42 for covering the surface of the encapsulating film 41 facing away from the battery string. The battery cells 100 are electrically connected in a single piece or in multiple pieces to form multiple battery strings, which are electrically connected in series and / or parallel. The battery cell 100 can be a single cell or a sliced ​​cell; a sliced ​​cell refers to a cell formed by cutting a single, complete cell.

[0116] in, Figure 15 This is a partial three-dimensional structural diagram of a photovoltaic module provided in another embodiment of the present disclosure. Figure 16 for Figure 15 A schematic diagram of a partial cross-sectional structure along the first section direction AA1. Figure 17 for Figure 15 A schematic diagram of a partial cross-sectional structure along the second section direction BB1.

[0117] It should be noted that in the step of covering the surface of the battery string with the encapsulating film 41, when the material of the pre-adhesive film 102 and the encapsulating film 41 are the same, there will be no obvious boundary between the two in the final photovoltaic module. Figure 16 and Figure 17 The dotted line in the encapsulating film 41 indicates the approximate area where the pre-adhesive film 102 is located. In practical applications, the materials of the pre-adhesive film and the encapsulating film can also be different, and there can be a clear boundary between the pre-adhesive film and the encapsulating film in the final photovoltaic module.

[0118] In some embodiments, reference Figure 15 or Figure 17 Multiple solar cells 100 can be electrically connected to each other via solder strips 101. Figure 15 and Figure 17This illustration only shows one possible positional relationship between the battery cells 100. The battery cells 100 can also be arranged with their grid lines of different polarities facing the same side. That is, the grid lines of adjacent battery cells 100 can be arranged in the order of first polarity, second polarity, and first polarity, respectively. In this case, the solder ribbon 101 connects the same side of two adjacent battery cells 100. In other embodiments, the electrodes of the same polarity in the battery cells are arranged in the same direction, or in other words, the electrodes of each battery cell with positive polarity are arranged facing the same side, so that the solder ribbon connects different sides of two adjacent battery cells respectively.

[0119] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the battery cell 100, and the second encapsulating layer covers the other of the front or back sides of the battery cell 100. Specifically, at least one of the first encapsulating layer or the second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first encapsulating layer or the second encapsulating layer can also be an EP film, EPE film, or PVP film. Among them, EP film refers to a co-extruded film composed of stacked EVA film and POE film; 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. Co-extruded films 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.

[0120] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0121] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0122] In some cases, when the solar cell 100 is a cell with main grids, the surface of the solar cell 100 has a plurality of main grids spaced apart along a first direction X and a plurality of sub-grids spaced apart along a third direction Z. The main grid includes main grid connection lines and pads located on the main grid connection lines. During the process of constructing a cell string using the solar cells 100, the solder ribbon 101 is electrically connected to at least one main grid on each of two adjacent solar cells 100.

[0123] In other cases, when the cell 100 is a gridless cell, the surface of the cell 100 has a plurality of sub-grids arranged at intervals along the third direction Z. During the process of constructing a cell string using the cell 100, the solder ribbon 101 is electrically connected to the plurality of sub-grids on each of two adjacent cells 100.

[0124] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A method for preparing a photovoltaic module, characterized in that, include: At least two battery cells and multiple solder strips are provided, and the solder strips are placed in a predetermined area of ​​the battery cells, wherein the portion of the battery cell located in the predetermined area has a conductive portion; A pre-adhesive film is provided, wherein the pre-adhesive film has a plurality of positioning grooves on the side facing the battery cell, and each solder ribbon corresponds to at least one positioning groove; the pre-adhesive film includes a body portion and a positioning portion, the positioning portion being located on the side of the body portion closer to the battery cell, the positioning portion protruding towards the battery cell relative to the body portion, and the positioning portion having the positioning grooves therein, different portions of the positioning portion having different thicknesses in a second direction, the positioning grooves being directly opposite the solder ribbons along the second direction and the positioning grooves being spaced apart along a first direction, the first direction being the extension direction of the solder ribbons, and the second direction being the thickness direction of the battery cell; The pre-bonded film is applied to the side of the solder ribbon away from the battery cell, and the positioning groove accommodates at least a portion of the solder ribbon. A pressure plate is provided, which is placed on the side of the pre-adhesive film away from the battery cell, and pressure is applied to the pre-adhesive film through the pressure plate, so that the pre-adhesive film adheres the welding ribbon to the preset area, and so that multiple battery cells are connected into a battery string to be welded. The battery string to be welded is fed into the lamination stage, where the lamination temperature is greater than or equal to the melting point of the material constituting the outer layer of the solder strip, so as to achieve alloying of the solder strip and the conductive part.

2. The preparation method according to claim 1, characterized in that, The conductive part is a solder pad, and a single solder strip is directly opposite to a plurality of solder pads arranged at intervals along a first direction along a second direction; the positioning groove and the solder pad are directly opposite each other along the second direction.

3. The preparation method according to claim 1 or 2, characterized in that, Along the third direction upward, the distance between the welding strip and the positioning groove is 0.1mm~0.3mm, and the third direction is perpendicular to the extension direction of the welding strip.

4. The preparation method according to claim 1 or 2, characterized in that, The pressure plate has a protrusion on the side facing the pre-bonded film, and a single protrusion is directly opposite at least one of the positioning grooves along a second direction, which is the thickness direction of the battery cell.

5. The preparation method according to claim 4, characterized in that, The protrusion is an elongated protrusion extending along the first direction, and the protrusion corresponds one-to-one with the welding strip.

6. The preparation method according to claim 4, characterized in that, The plurality of protrusions are arranged in an array along the first direction and a third direction, the third direction being perpendicular to the extension direction of the solder strip; a single solder strip is directly opposite to the plurality of positioning portions arranged at intervals along the first direction along the second direction.

7. The preparation method according to claim 1, characterized in that, The material constituting the outer layer of the solder strip includes tin, the lamination temperature is 140°C to 170°C; and / or the duration of the lamination stage is 4 min to 5 min.

8. The preparation method according to claim 1, characterized in that, Also includes: A base plate is provided for supporting the side of the battery cell away from the solder strip, and the base plate has a first heating part or the pressure plate has a second heating part; In the step of applying pressure to the pre-bonded film through the pressure plate, the battery cell, the solder ribbon, and the pre-bonded film are heated by the first heating part or the second heating part.

9. A photovoltaic module, characterized in that, include: A photovoltaic module formed by the method for preparing a photovoltaic module as described in any one of claims 1 to 8.

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