Photovoltaic module and photovoltaic module manufacturing method

Abstract

The present application relates to the technical field of photovoltaics. Disclosed are a photovoltaic module and a photovoltaic module manufacturing method, which are used to solve the problem of a poor insulation effect. The photovoltaic module comprises: a solar cell provided with an electrode on the back surface; an insulating layer arranged on the face of the solar cell provided with the electrode, wherein the insulating layer is provided with a through hole penetrating the insulating layer in the direction of thickness thereof, the through hole is configured to at least partially expose an electrical connection portion of the electrode, the insulating layer comprises a support layer and first insulating layers, the first insulating layers are arranged on two opposite faces of the support layer in the direction of thickness thereof, and the first insulating layers cover the side surfaces of the support layer close to the through hole; a patterned electrically conductive layer, which is arranged on the face of the insulating layer facing away from the solar cell and provided with an electrically conductive area; and an electrically conductive bonding portion, which is located in the through hole and electrically connected to the electrical connection portion and the electrically conductive area.

Description

A photovoltaic module and a method for manufacturing a photovoltaic module

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024119232589, filed on December 24, 2024, entitled "A Photovoltaic Module and a Method for Preparing a Photovoltaic Module", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of photovoltaic module technology, and in particular to a photovoltaic module and a method for manufacturing a photovoltaic module. Background Technology

[0004] Currently, photovoltaic (PV) module manufacturing typically employs either ribbon bonding or conductive backsheet bonding technologies. PV modules manufactured using conductive backsheet technology offer advantages such as high aesthetics, high power output, and high conversion efficiency. In PV modules with conductive backsheets, an insulating layer is used to isolate the conductive backsheet from the solar cells. Conductive adhesive is filled into the openings of the insulating layer, and this adhesive interconnects the solar cells and the conductive backsheet, achieving conductive connections between the electrodes on the solar cells and the corresponding conductive areas on the conductive backsheet. A busbar then collects the current from the conductive backsheet, thus completing the current collection from the solar cells.

[0005] However, in existing photovoltaic modules with conductive backsheets, the sealing performance of the insulation layer needs improvement. Moisture can easily enter the interior of the photovoltaic module through the insulation layer, reducing the corrosion resistance of the photovoltaic module. Moisture can also affect the insulation effect of the photovoltaic module. Summary of the Invention

[0006] The purpose of this application is to provide a photovoltaic module and a method for manufacturing a photovoltaic module, so as to improve the sealing performance and insulation effect of the photovoltaic module.

[0007] In a first aspect, this application provides a photovoltaic module, comprising:

[0008] A solar cell, with electrodes on its back side;

[0009] An insulating layer is disposed on the back side of the battery cell. The insulating layer has a through hole extending along its thickness direction. The through hole is used to expose at least part of the electrical connection portion of the electrode. The insulating layer includes a support layer and a first insulating layer. The first insulating layer is disposed on two opposite sides of the support layer in the thickness direction, and the first insulating layer covers the side surface of the support layer near the through hole.

[0010] A patterned conductive layer is disposed on the side of the insulating layer opposite to the battery cell, and the conductive layer has conductive areas;

[0011] The conductive joint is located inside the through hole and is electrically connected to the electrical connection part and the conductive area.

[0012] With the above technical solution, the insulating layer between the solar cell and the conductive layer includes a support layer and a first insulating layer. The first insulating layer is disposed on two opposite sides of the support layer in the thickness direction. The insulating layer is bonded and fixed to the solar cell and the conductive layer respectively through the first insulating layer on both sides, playing a role in insulation and fixation. The support layer provides support for the insulating layer, making it less likely for the overall deformation of the insulating layer to be large, which would reduce the alignment accuracy between the insulating layer and the solar cell and the conductive layer. Moreover, the first insulating layer covers the side surface of the support layer near the through hole at the through hole of the insulating layer. That is, the inner wall of the through hole is the first insulating layer. The support layer is wrapped by the first insulating layer, and the gaps between the layers of the insulating layer are sealed by the first insulating layer, thereby ensuring the sealing performance of the insulating layer. Moisture is not easily able to enter the interior of the photovoltaic module through the insulating layer, which improves the corrosion resistance of the photovoltaic module and reduces the impact of moisture on the insulation effect. In addition, the first insulating layer on the inner wall of the through hole isolates the contact between the conductive joint and the surrounding electrodes, preventing short circuits and improving the insulation effect of the photovoltaic module.

[0013] In some possible implementations, a cavity is formed between the conductive joint and the inner wall of the through-hole. The inner wall of the insulating layer through-hole and the conductive joint located within the through-hole are separated by the cavity, preventing the insulating layer and the conductive joint from contacting each other. This avoids the insulating layer and the conductive joint penetrating each other's interior, thus preventing short circuits or poor solder joints and improving the insulation performance of the photovoltaic module.

[0014] In some possible implementations, the cavity has a first vacuum level. That is, the cavity is a micro-vacuum cavity. The presence of air bubbles in the insulation layer can be reduced by the cavity with the first vacuum level, thereby improving the sealing and insulation effect of the insulation layer.

[0015] In some possible implementations, in the thickness direction of the insulating layer, the non-edge portion of the first insulating layer covering the side surface of the support layer at the through-hole protrudes towards the through-hole. Thus, when a vacuum cavity exists within the through-hole, the non-edge portion of the first insulating layer protruding towards the through-hole without contacting the conductive bonding portion reduces the gap, increases the isolation area of ​​the insulating layer between the conductive layer and the solar cell, further reduces the risk of electrical contact between the conductive layer and the solar cell, and improves the insulation effect.

[0016] In some possible implementations, the distance by which the first insulating layer protrudes into the through-hole gradually increases from the edge to the non-edge portion of the first insulating layer on the side surface of the support layer. That is, the structure of the first insulating layer protruding into the through-hole resembles a triangular prism, with the ridge located in the middle of the first insulating layer, and the facets on both sides of the ridge being approximately planar or curved. This triangular prism-shaped protrusion structure can improve the structural strength of the first insulating layer on the side surface of the support layer.

[0017] In some possible implementations, along the direction from the conductive layer to the solar cell, the first insulating layer covering the support layer side surface at the through-hole gradually protrudes into the through-hole. That is, the first insulating layer on the support layer side surface is thicker on the side closer to the solar cell and thinner on the side closer to the conductive layer, and the thickness of the first insulating layer on the support layer side surface gradually increases from the conductive layer to the solar cell. On the one hand, when there is a vacuum cavity within the through-hole, the structure of the first insulating layer protruding into the through-hole can reduce the gap, increase the isolation area of ​​the insulating layer between the conductive layer and the solar cell, further reduce the risk of electrical contact between the conductive layer and the solar cell, and improve the insulation effect. On the other hand, it increases the bonding and fixing area between the first insulating layer and the solar cell, improving the bonding strength between the solar cell and the insulating layer. Furthermore, the closer distance between the first insulating layer and the electrodes on the solar cell can improve the insulation effect between dissimilar electrodes.

[0018] In some possible implementations, the first insulating layer covering the side surface of the support layer along the direction from the conductive layer to the solar cell is curved. That is, along the direction from the conductive layer to the solar cell, the first insulating layer on the side surface of the support layer gradually protrudes into the through-hole, and the surface of the protruding structure is curved. The curved protruding structure improves the structural strength of the first insulating layer on the side surface of the support layer, and the edge of the first insulating layer near the solar cell is less prone to warping, thus improving insulation reliability.

[0019] In some possible implementations, the melting point of the first insulating layer is T2, the melting point of the conductive bonding portion is T3, and the melting point of the support layer is T4; where T2 ≤ T3 < T4. With this configuration, during the heat lamination process, the temperature can be gradually increased, allowing the first insulating layer to melt first and establish a bond with the conductive layer and the battery cell. At this point, the conductive bonding portion has not yet melted and therefore will not flow into the insulating layer, affecting its insulation performance. Subsequently, as the temperature continues to rise, the conductive bonding portion begins to melt and establish a bond with the conductive layer and the electrode. After cooling, the conductive bonding portion solidifies, preventing the insulating layer and the conductive bonding portion from intruding into each other, thus avoiding impacts on insulation and welding performance. Because the support layer has a high melting temperature, it will not melt or deform during the heat lamination process, improving the supporting and insulating effect of the insulating layer.

[0020] In some possible implementations, the material of the first insulating layer includes one or more of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, and vinyl chloride; and / or, the thickness of the first insulating layer located on opposite sides of the support layer in the thickness direction is 18 μm to 200 μm.

[0021] When using the above technical solution, the first insulating layer of these materials possesses a certain strength and adhesiveness after heating. The first insulating layer is a hot-melt film that melts during the heating and lamination process and bonds to the conductive layer or solar cell. After cooling, it retains a certain strength and is not easily deformed, improving the alignment accuracy of the insulating layer between the conductive layer and the solar cell. If the thickness of the first insulating layer is less than this range, the bonding and insulation effects are poor, and during the heating and lamination process, the amount of molten material is less, making it difficult to cross-link and wrap the side surface of the support layer near the through-hole, affecting the sealing effect of the insulating layer. If the thickness of the first insulating layer is greater than this range, it results in a thicker insulating layer, increasing material costs and the overall thickness and weight of the photovoltaic module. Therefore, the thickness of the first insulating layer is selected to be 18μm to 200μm.

[0022] In some possible implementations, the support layer comprises a polymer film or a composite material layer; wherein the polymer film is made of one or more of polyethylene terephthalate and polyimide; the composite material layer is made of resin and filler, the filler being one or more of carbon fiber, glass fiber, glass wool, talc, graphene, and mica sheets; and / or, the thickness of the support layer is 18 μm to 300 μm.

[0023] When using the above technical solution, the support layer, made of the aforementioned material, exhibits high dimensional stability and temperature resistance, is less prone to thermal deformation, and improves the stability and reliability of the insulation layer. The thickness of the support layer ensures both the stability and reliability of the support, while simultaneously reducing cost and the overall thickness and weight of the photovoltaic module.

[0024] In some possible implementations, the insulating layer further includes an adhesive layer located between the support layer and the first insulating layer; the adhesive layer is made of one or more of polyurethane and acrylic; and / or, the heat resistance temperature of the adhesive layer is greater than 170°C. The adhesive layer improves the adhesion between the first insulating layer and the support layer, thereby enhancing the stability and reliability of the insulating layer. Since the heat resistance temperature of the adhesive layer is greater than the melting point of the first insulating layer, the adhesive layer will not melt when the first insulating layer melts and bonds to the conductive layer or battery cell, ensuring the bonding stability between the first insulating layer and the support layer.

[0025] In some possible implementations, the conductive layer is an electroplated metal conductive film or metal foil; and / or, the material of the conductive layer includes one or more of gold, silver, copper, and aluminum; and / or, the thickness of the conductive layer is 15μm to 100μm. This material provides a conductive layer with good toughness during coating and patterning processes, making it less prone to breakage. The thickness of the conductive layer meets conductivity requirements while reducing cost and the overall thickness and weight of the photovoltaic module.

[0026] In some possible implementations, the ratio of the projected area of ​​the through-hole on the solar cell to the projected area of ​​the conductive bonding portion on the solar cell is greater than 1:1 and less than or equal to 50:1. That is, the conductive bonding portion does not completely fill the through-hole; rather, there is a gap between the conductive bonding portion and the inner wall of the through-hole. This prevents the insulating layer and the conductive bonding portion from melting and penetrating into each other, which could lead to short circuits or poor soldering. The area ratio does not exceed this range, preventing the conductive bonding portion area from being too small, ensuring good conductive contact between the conductive bonding portion and the conductive layer and electrodes, and preventing the through-hole area from being too large, which could affect the structural strength and insulating support effect of the insulating layer.

[0027] In some possible implementations, the ratio of the maximum width of the conductive joint to the width of the via in the extension direction of the sub-gate electrode is greater than or equal to 1:100 and less than 1:1. That is, the conductive joint does not completely fill the via; instead, there is a gap between the conductive joint and the inner wall of the via. This prevents the insulating layer and the conductive joint from melting and penetrating into each other, which could lead to short circuits or poor solder joints. The width ratio is not less than this range to avoid the conductive joint being too small, ensuring good conductive contact between the conductive joint and the conductive layer and the electrode, and to prevent the via from being too large, which could affect the structural strength and insulating support effect of the insulating layer.

[0028] In some possible implementations, the photovoltaic module also includes a first encapsulation plate, a first encapsulating film layer, a second encapsulating film layer, and a second encapsulation plate;

[0029] The first adhesive film layer covers the side of the battery cell that is away from the insulating layer;

[0030] The first encapsulation board covers the side of the first adhesive film layer that is away from the battery cell;

[0031] The second adhesive film layer covers the side of the conductive layer away from the battery cell, and the second adhesive film layer is filled in the gap area between adjacent conductive areas of the conductive layer, and the second adhesive film layer in the gap area is cross-linked with the insulating layer.

[0032] The second encapsulation board covers the side of the second encapsulation film layer that is away from the battery cell;

[0033] The first encapsulation board is a transparent board, and the second encapsulation board is either a transparent board or an opaque board.

[0034] Using the above technical solution, the first encapsulation layer fixes the position of the solar cell and secures it to the first encapsulation plate, preventing short circuits and poor appearance caused by cell displacement. The second encapsulation layer fixes the conductive layer and the second encapsulation plate. The second encapsulation layer fills the gaps in the conductive layer and cross-links with the insulating layer, improving the overall connection strength and reliability of the photovoltaic module. The first encapsulation plate is transparent, allowing light to enter the solar cell.

[0035] In some possible implementations, the melting crosslinking temperature of the first and second encapsulant layers is T1, the melting point of the first insulating layer is T2, the melting point of the conductive bonding portion is T3, and the melting point of the support layer is T4; wherein T1 < T2 ≤ T3 < T4. With this configuration, during the heating and lamination process, the temperature can be gradually increased, first to the melting crosslinking temperature T1 of the first and second encapsulant layers, allowing the first encapsulant layer to melt and interconnect the solar cell and the first encapsulation plate. Simultaneously, the second encapsulant layer melts and crosslinks, bonding the conductive layer to the second encapsulation plate. Then, the temperature continues to rise, gradually melting the first insulating layer and the conductive bonding portion, preventing the conductive bonding portion from penetrating into each other after melting and causing short circuits or poor solder joints, thus improving the insulation performance of the photovoltaic module.

[0036] In some possible implementations, 70℃≤T1≤110℃; 100℃≤T2≤140℃; 140℃≤T3≤168℃; T4≥250℃. As the temperature gradually increases during the heating and lamination process, the layers gradually melt and establish adhesion.

[0037] In some possible implementations, the thickness of the conductive joint is 25 μm to 1450 μm; and / or, the diameter of the conductive joint is 60 μm to 2200 μm; and / or, the thickness of the insulating layer is 15 μm to 250 μm.

[0038] Secondly, this application also provides a method for manufacturing a photovoltaic module, comprising:

[0039] A battery cell, an insulating layer, and a patterned conductive layer are provided. The back side of the battery cell has an electrode. The insulating layer has a through hole extending along its thickness direction. The insulating layer includes a support layer and a first insulating layer. The first insulating layer is disposed on two opposite sides of the support layer in the thickness direction. The conductive layer has a conductive region.

[0040] The conductive bonding portion is printed on the electrical connection portion of the electrode of the battery cell or on the corresponding through hole position of the conductive area of ​​the conductive layer.

[0041] The battery cell, insulating layer and conductive layer are stacked in sequence, wherein the through hole at least partially exposes the electrical connection part and the conductive area, and the conductive joint part is located in the through hole and contacts the electrical connection part and the conductive area.

[0042] Heating and laminating releases the gas between the battery cell, insulating layer, conductive layer, and conductive joint, causing the first insulating layer on both sides of the insulating layer to melt and bond to the battery cell and conductive layer respectively. The first insulating layer melts and covers the side surface of the support layer near the through hole, and the conductive joint melts and bonds to the electrical connection and conductive area.

[0043] When the above technical solution is adopted, the photovoltaic module obtained by this preparation method has the same beneficial effects as the photovoltaic module in any of the first aspects, which will not be repeated here.

[0044] In some possible implementations, the melting point of the first insulating layer is T2, the melting point of the conductive junction is T3, and the melting point of the support layer is T4; wherein, T2≤T3<T4;

[0045] Heating and laminating includes:

[0046] During the lamination process, the temperature is raised to T2, which melts the first insulating layer and bonds it to the conductive layer and the battery cell, and the first insulating layer melts and covers the side surface of the support layer near the through hole.

[0047] The temperature is raised to T3, causing the conductive joint to melt and bond and fix with the conductive area and electrical connection of the same polarity.

[0048] With the above technical solution, during the heat lamination process, the temperature can be gradually increased, allowing the first insulating layer to melt first and establish a bond with the conductive layer and the battery cell. At this point, the conductive bonding portion has not yet melted, so it will not flow into the insulating layer and affect its insulation effect. Subsequently, as the temperature continues to rise, the conductive bonding portion begins to melt and establish a bond with the conductive layer and the electrical connection portion. After cooling, the conductive bonding portion solidifies, preventing the insulating layer and the conductive bonding portion from intruding into each other and affecting the insulation and welding effects. Because the support layer has a high melting temperature, it will not melt or deform during the heat lamination process, thus improving the support and insulation effect of the insulating layer.

[0049] In some possible implementations, providing the battery cell, insulating layer and patterned conductive layer also includes providing a first adhesive film layer, a second adhesive film layer, a first encapsulation board and a second encapsulation board, wherein the insulating layer, conductive layer, second adhesive film layer and second encapsulation board are sequentially stacked to form an integrated conductive backplane;

[0050] The process of stacking battery cells, insulating layers, and conductive layers in sequence also includes:

[0051] The battery cells and the integrated conductive backplate are stacked and pre-fixed in sequence;

[0052] The first adhesive film layer is laid on the side of the battery cell that is away from the insulating layer;

[0053] The first encapsulation plate is laid on the side of the first adhesive film layer that is away from the battery cell;

[0054] Heating and laminating includes: heating and laminating a first encapsulation board, a first adhesive film layer, a battery cell, and an integrated conductive backsheet.

[0055] With the above technical solution, the insulating layer, conductive layer, second encapsulating film layer and second encapsulation board are stacked into an integrated conductive backplane, which is convenient for arrangement and combination with the battery cells and simplifies the process.

[0056] In some possible implementations, the melt crosslinking temperature of the first adhesive film layer and the second adhesive film layer is T1, where T1 < T2 ≤ T3 < T4;

[0057] Before heating to T2 during the lamination process, the heating and lamination process also includes:

[0058] During the lamination process, the temperature is raised to T1, causing the first adhesive film layer to melt and bond to the battery cell and the first encapsulation plate, and causing the second adhesive film layer to melt and bond to the conductive layer and the second encapsulation plate. The second adhesive film layer melts and flows into the space between adjacent conductive areas of the conductive layer and crosslinks with the first insulating layer.

[0059] With the above technical solution, during the heating and lamination process, the temperature can be gradually increased. First, the temperature is increased to the melting and cross-linking temperature T1 of the first and second adhesive film layers, so that the first adhesive film layer melts and interconnects with the conductive layer and the second encapsulation plate. At the same time, the second adhesive film layer melts and cross-links, so that the cell is bonded and fixed to the first encapsulation plate. Then, the temperature continues to rise, gradually realizing the melting and cross-linking of the first insulating layer and the melting and cross-linking of the conductive joint. This avoids the conductive joint from intruding into the other side after melting with the first insulating layer, causing short circuits or poor soldering, and improves the insulation effect of the photovoltaic module.

[0060] In some possible implementations, 70℃≤T1≤110℃; 100℃≤T2≤140℃; 140℃≤T3≤168℃; T4≥250℃. As the temperature gradually increases during the heating and lamination process, the layers gradually melt and cross-link.

[0061] In some possible implementations, the ratio of the projected area of ​​the printed conductive bonding portion on the solar cell to the projected area of ​​the through-hole on the solar cell is greater than or equal to 1:50 and less than 1:1. That is, during printing, the conductive bonding portion does not completely fill the through-hole; instead, there is a gap between the conductive bonding portion and the inner wall of the through-hole. This prevents the insulating layer and the conductive bonding portion from melting and penetrating into each other during lamination, which could lead to short circuits or poor solder joints. The area ratio is not less than this range to avoid the conductive bonding portion being too small, ensuring good conductive contact between the conductive bonding portion and the conductive layer and electrodes. Attached Figure Description

[0062] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0063] Figure 1 is a schematic diagram of the layered structure of a photovoltaic module provided in an embodiment of this application;

[0064] Figure 2 is a schematic diagram of the structure of the insulating layer of a photovoltaic module provided in an embodiment of this application;

[0065] Figure 3 is a schematic diagram of the structure of a photovoltaic module before lamination of the cell, insulating layer and conductive layer according to an embodiment of this application;

[0066] Figure 4 is a schematic diagram of the structure of a photovoltaic module after lamination of the cell, insulating layer and conductive layer according to an embodiment of this application;

[0067] Figure 5 is a schematic diagram of the structure of a photovoltaic module after further lamination of the cell, insulating layer and conductive layer according to an embodiment of this application;

[0068] Figure 6 is a schematic diagram of the structure of a photovoltaic module after lamination molding, including the cell, insulating layer, and conductive layer, according to an embodiment of this application.

[0069] Figure 7 is a schematic diagram of the structure of a photovoltaic module before lamination of the insulating layer, conductive layer and second encapsulant layer according to an embodiment of this application;

[0070] Figure 8 is a schematic diagram of the structure after lamination of the insulating layer, conductive layer and second adhesive film layer in Figure 7;

[0071] Figure 9 is a schematic diagram of the cell arrangement of a photovoltaic module provided in an embodiment of this application.

[0072] Reference numerals in the attached figures: 1 is the first encapsulation plate, 2 is the first adhesive film layer, 3 is the battery cell, 31 is the electrode, 32 is the conductive joint, 33 is the string gap, 34 is the cell gap, 4 is the insulating layer, 41 is the support layer, 42 is the adhesive layer, 43 is the first insulating layer, 44 is the through hole, 45 is the cavity, 5 is the conductive layer, 51 is the first conductive area, 52 is the second conductive area, 53 is the spacing area, 6 is the second adhesive film layer, and 7 is the second encapsulation plate. Specific Implementation

[0073] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0074] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0075] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly specified. "Several" means one or more, unless otherwise expressly specified.

[0076] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0077] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] As shown in Figures 1-7, this application provides a photovoltaic module, including a conductive backplate A, a solar cell 3, a first encapsulating film layer 2, and a first encapsulation plate 1 stacked sequentially. The conductive backplate A includes a patterned conductive layer 5 and an insulating layer 4 disposed thereon. The solar cell 3 is a back-contact solar cell. The back side of the solar cell 3 (the side opposite to the light-receiving surface of the solar cell) has an electrode 31, which includes a positive electrode and a negative electrode. The electrode 31 may include a sub-grid electrode, or it may include a sub-grid electrode and a main grid electrode. The electrode 31 may have an electrical connection portion for conductive connection. When the electrode 31 includes a main grid electrode, the electrical connection portion may be part of the main grid electrode or connected to the main grid electrode. The connecting pads can be spaced apart on the main gate electrode, facilitating connection to the conductive junction 32. When the electrode 31 only includes the sub-gate electrode, the electrical connection can be a portion of the sub-gate electrode, a thickened section on the sub-gate electrode, or an electrical connection point electrically connected to the sub-gate electrode. The insulating layer 4 is disposed on the back of the battery cell 3, located between the conductive layer 5 and the battery cell 3. The insulating layer 4 has through holes 44 extending along its thickness direction. The through holes 44 are used to at least partially expose the electrical connection and the conductive layer 5. The shape of the through holes 44 can be circular, rectangular, polygonal, strip-shaped, etc., and is not specifically limited, as long as it can at least expose the electrical connection and the conductive layer 5. Layer 4 includes a support layer 41 and a first insulating layer 43. The first insulating layer 43 is disposed on two opposite sides of the support layer 41 in the thickness direction, and the first insulating layer 43 covers the side surface of the support layer 41 near the through hole 44. The insulating layer 4 is bonded and fixed to the battery cell 3 and the conductive layer 5 respectively through the two opposite sides of the first insulating layer 43. The conductive layer 5 can be patterned by laser, die-cutting, stamping, etc. The conductive layer 5 is disposed on the side of the insulating layer 4 away from the battery cell 3 and is bonded and fixed to the first insulating layer 43. The conductive layer 5 has conductive regions and spacing regions 53. The conductive regions include a first conductive region 51 and a second conductive region 52. The two conductive regions 52 are separated by a gap region 53; the conductive joint 32 is located in the through hole 44 of the insulating layer 4, and the electrical connection part on the battery cell 3 and the conductive region are electrically connected through the conductive joint 32. For example, the positive electrode electrical connection part of the battery cell 3 is electrically connected to the first conductive region 51 of the conductive layer 5 through the conductive joint 32 in the corresponding through hole 44, and the negative electrode electrical connection part of the battery cell 3 is electrically connected to the second conductive region 52 of the conductive layer 5 through the corresponding through hole 44. Electrodes 31 of different polarities and different conductive regions are insulated from each other by the insulating layer 4. This arrangement allows multiple battery cells 3 to be connected in series or in parallel through the conductive layer 5.

[0079] During operation, the current generated by the solar cell 3 is collected at the electrode 31 and transmitted to the conductive area on the conductive layer 5 through the conductive joint 32. The conductive layer 5 then transmits the current to the busbar and finally to the outside through the connector. In this photovoltaic module, the insulating layer 4 includes a support layer 41 and a first insulating layer 43. The first insulating layer 43 is disposed on two opposite sides of the support layer 41 in the thickness direction. The insulating layer 4 can be bonded and fixed to the solar cell 3 and the conductive layer 5 respectively by the first insulating layer 43 disposed on both sides, playing a role in insulation and fixation. The support layer 41 provides support for the insulating layer 4, making it less likely that the overall thermal deformation of the insulating layer 4 will reduce the alignment accuracy between the insulating layer 4 and the solar cell 3 and the conductive layer 5, or that the large deformation of the through hole 44 during the opening of the through hole 44 or during lamination will affect the filling of the conductive joint 32. Furthermore, the first insulating layer 43 covers the side surface of the support layer 41 near the through hole 44 at the through hole 44 of the insulating layer 4. That is, the inner wall of the through hole 44 is the first insulating layer 43, and the support layer 41 is wrapped by the first insulating layer 43. The gaps between the layers of the insulating layer 4 are sealed by the first insulating layer 43, thereby ensuring the sealing performance of the insulating layer 4. Moisture is not easily able to enter the interior of the photovoltaic module through the insulating layer 4, which improves the corrosion resistance of the photovoltaic module and reduces the impact of moisture on the insulation effect. In addition, the first insulating layer 43 on the inner wall of the through hole 44 isolates the contact between the conductive joint 32 and the surrounding electrode 31, which will not cause a short circuit and improves the insulation effect of the photovoltaic module.

[0080] As shown in Figures 3-6, in some embodiments, a cavity is formed between the conductive joint 32 and the inner wall of the through hole 44. Specifically, a cavity structure is formed between the outer contour of the conductive joint 32 and the inner wall of the through hole 44. This allows the inner wall of the through hole 44 on the insulating layer 4 and the conductive joint 32 located in the through hole 44 to be separated by the cavity 45, reducing the possibility of direct contact between the insulating layer 4 and the conductive joint 32. This avoids the conductive joint 32 from intruding into the interior of the insulating layer 4 and contacting the opposite electrode or conductive area, causing a short circuit, or the first insulating layer 43 of the insulating layer 4 intruding into the interior of the conductive joint 32, causing a poor weld on the conductive joint 32. This improves the insulation effect of the photovoltaic module and the reliability of the electrical connection.

[0081] Furthermore, in some embodiments, the cavity 45 has a first vacuum degree, i.e., the cavity is a micro-vacuum cavity, thereby improving the sealing and insulation effect of the insulating layer 4. The vacuum degree range during the lamination process is -0 kPa to -100 kPa. More specifically, the first vacuum degree of the cavity 45 is -0 kPa to -60 kPa, which is formed by evacuating the gas from the through-hole 44 during the heating and lamination process. Compared to a cavity, the micro-vacuum cavity has a certain effect on forming a special shape (as described below) for the first insulating layer 43.

[0082] As shown in Figure 6, in some embodiments, in the thickness direction of the insulating layer 4, the non-edge portion of the first insulating layer 43 covering the side surface of the support layer 41 at the through hole 44 protrudes into the through hole 44. The non-edge portion refers to a position near the center in the thickness direction of the insulating layer 4. Thus, when there is a cavity 45 within the through hole 44, the non-edge portion of the first insulating layer 43 protrudes into the through hole 44, forming a protruding structure, as shown on the left side of Figure 6, where the first insulating layer 43 surrounds the support layer 41. This protruding structure does not contact the conductive joint 32. The protruding structure reduces the gap between the inner wall of the through hole 44 and the conductive joint 32, increasing the physical isolation area (projected area on the battery cell 3) of the insulating layer 4 between the conductive layer 5 and the battery cell 3, further reducing the risk of electrical contact between the conductive layer 5 and the battery cell 3, and improving the insulation effect.

[0083] Furthermore, in this embodiment, as shown in the protruding structure on the left side of Figure 6, the distance by which the first insulating layer 43 protrudes into the through hole 44 gradually increases along the direction from the edge portion to the non-edge portion of the first insulating layer 43 on the side surface of the support layer 41. Here, the edge portion refers to the two edges in the thickness direction of the insulating layer 4, and the non-edge portion refers to the portion located near the middle between the two edge portions. This protruding structure of the first insulating layer 43 into the through hole 44 is similar to a triangular prism structure, with the ridge line located in the middle of the first insulating layer 43, and the facets on both sides of the ridge line approximately flat or curved. As can be seen from the cross-section of Figure 6, the cross-section of the protruding structure is similar to a triangle with equal upper and lower sides. This triangular prism-shaped protruding structure can improve the structural strength of the first insulating layer 43 on the side surface of the support layer 41.

[0084] As shown on the right side of Figure 6, along the direction from the conductive layer 5 to the battery cell 3, the first insulating layer 43 covering the side surface of the support layer 41 at the through hole 44 gradually protrudes into the through hole 44. That is, the first insulating layer 43 on the side surface of the support layer 41 is thicker on the side closer to the battery cell 3 and thinner on the side closer to the conductive layer 5, and the thickness of the first insulating layer 43 on the side surface of the support layer 41 gradually increases from the conductive layer 5 to the battery cell 3. On the one hand, with a cavity 45 inside the through hole 44, the structure of the first insulating layer 43 protruding into the through hole 44 can reduce the gap between the conductive joint 32 and the inner wall of the through hole 44, increase the physical isolation area (projected area on the battery cell 3) of the insulating layer 4 between the conductive layer 5 and the battery cell 3, further reduce the risk of electrical contact between the conductive layer 5 and the battery cell 3, and improve the insulation effect. On the other hand, it increases the bonding and fixing area between the first insulating layer 43 and the battery cell 3, and improves the bonding strength between the battery cell 3 and the insulating layer 4. In addition, the first insulating layer 43 is closer to the electrode 31 on the battery cell 3, which can improve the insulation effect between dissimilar electrodes.

[0085] Furthermore, in this embodiment, as shown on the right side of FIG6, the first insulating layer 43 covering the side surface of the support layer 41 along the direction from the conductive layer 5 to the battery cell 3 is an arc surface. That is, along the direction from the conductive layer 5 to the battery cell 3, the first insulating layer 43 on the side surface of the support layer 41 gradually protrudes into the through hole 44, and the surface of the protruding structure is an arc surface, which bends towards the through hole 44. The thickness of the protruding structure with an arc surface is relatively thick, which improves the structural strength of the first insulating layer 43 on the side surface of the support layer 41, and the edge of the first insulating layer 43 near the battery cell 3 is less prone to warping, thus improving insulation reliability.

[0086] In some embodiments, the melting point of the first insulating layer 43 is T2, the melting point of the conductive bonding portion 32 is T3, and the melting point of the support layer 41 is T4; wherein, T2≤T3<T4. T2≤T3 indicates that the melting point of the first insulating layer 43 is less than or equal to the melting point of the conductive bonding portion 32.

[0087] By selecting the first insulating layer 43, conductive bonding portion 32, and support layer 41 within the aforementioned temperature range, the temperature can be gradually increased during the heating and lamination process. First, the temperature is increased to a lower value of T2, causing the first insulating layer 43 to melt. Then, the temperature is increased to a higher value of T2, allowing the first insulating layer 43 to establish an adhesive relationship with the conductive layer 5 and the battery cell 3. At this time, the conductive bonding portion 32 has not yet begun to melt, so it will not flow into the insulating layer 4 and affect the insulation effect of the insulating layer 4. Even if the conductive bonding portion 32 begins to melt at this time, since the first insulating layer 43 has already established an adhesive relationship with the conductive layer 5 and the battery cell 3, the melted conductive bonding portion 32 will not connect with the surrounding dissimilar electrode 31 through the insulating layer 4 and cause a short circuit. As the temperature continues to rise to the lower value of T3, the conductive bonding portion 32 begins to melt. Further heating to the higher value of T3 allows the conductive bonding portion 32 to bond with the conductive layer 5 and the electrode 31. After cooling, the conductive bonding portion 32 solidifies, forming a strong electrical connection between the conductive layer 5 and the electrode 31. Simultaneously, the presence of the cavity 45 prevents the insulating layer 4 from interfering with the conductive bonding portion 32, thus avoiding impacts on insulation and welding performance. Because the support layer 41 has a high melting point, the temperature during the heat lamination process will not rise to T4, preventing the support layer 41 from melting and deforming during heat lamination, thereby improving the support and insulation performance of the insulating layer 4.

[0088] In some possible implementations, the material of the first insulating layer 43 includes one or more of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, and vinyl chloride. For example, the first insulating layer 43 is primarily composed of polyethylene and blended with one or more of polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, and vinyl chloride, and formed into a hot-melt film by extrusion.

[0089] The first insulating layer 43 of these materials has a certain strength and adhesiveness after heating. The first insulating layer 43 is a hot melt film that can be laminated and attached to the support layer 41. It can melt and bond with the conductive layer 5 or the battery cell 3 during the heating and lamination process. After cooling, it has a certain strength and is not easily deformed, which improves the alignment accuracy of the insulating layer 4 between the conductive layer 5 and the battery cell 3.

[0090] In some embodiments, the thickness of the first insulating layer 43 on opposite sides of the support layer 41 in the thickness direction is 18 μm to 200 μm. For example, the thickness of the first insulating layer 43 on opposite sides of the support layer 41 is 18 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 60 μm, 75 μm, 90 μm, 120 μm, 150 μm, 170 μm, 200 μm, etc. If the thickness of the first insulating layer 43 is less than this range, the bonding and insulation effects are poor, and during the heat lamination process, the amount of melt in the first insulating layer 43 is less, making it difficult to cross-link on the side surface of the support layer 41 near the through-hole 44 to wrap the side surface of the support layer 41, thus affecting the sealing effect of the insulating layer 4. If the thickness of the first insulating layer 43 is greater than this range, the insulating layer 4 becomes thicker, increasing material costs and the overall thickness and weight of the photovoltaic module. Therefore, the thickness of the first insulating layer 43 is selected to be 18μm to 200μm. Further, the thickness of the first insulating layer 43 is selected to be 25μm to 50μm. The first insulating layer 43 in this thickness range can better balance the bonding and insulation effects. It is easier to cover and form a stable and reliable first insulating layer 43 on the side surface of the support layer 41. Moreover, the thickness and material cost are more suitable.

[0091] In some possible implementations, the support layer 41 includes a polymer film or a composite material layer; wherein the polymer film is made of one or more of PET (polyethylene terephthalate) and PI (polyimide), and when there are multiple materials, PET and PI can be two layers stacked together, or a blend of PET and PI; the composite material layer is made of resin and fillers, and the fillers include one or more of carbon fiber, glass fiber, glass wool, talc, graphene, and mica sheets.

[0092] The support layer 41 is made of the above-mentioned material, which has high dimensional stability and temperature resistance. In particular, by blending the resin with the filler to form a hybrid system, the dimensional stability and temperature resistance of the support layer 41 can be improved, the shrinkage rate of the support layer 41 can be lowered, the probability of thermal deformation can be reduced, and the stability and reliability of the first insulating layer 43 can be improved.

[0093] In some embodiments, the thickness of the support layer 41 is 18 μm to 300 μm. For example, the thickness of the support layer 41 can be 18 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 60 μm, 75 μm, 90 μm, 120 μm, 150 μm, 170 μm, 200 μm, 230 μm, 260 μm, 280 μm, 300 μm, etc. The thickness of the support layer 41 ensures the stability and reliability of the support while reducing cost and the overall thickness and weight of the photovoltaic module. Furthermore, a thickness of 25 μm to 50 μm for the support layer further balances stability, reliability, and cost, thickness, and weight reduction.

[0094] As shown in Figure 2, in some embodiments, the insulating layer 4 further includes an adhesive layer 42 located between the support layer 41 and the first insulating layer 43; that is, both opposite sides of the support layer 41 are bonded and fixed to the first insulating layer 43 by the adhesive layer 42. The adhesive layer 42 is made of one or more of polyurethane and acrylic, and when multiple materials are used, it can be a blend of polyurethane and acrylic. The adhesive layer 42 improves the bonding effect between the first insulating layer 43 and the support layer 41, thereby improving the stability and reliability of the insulating layer 4.

[0095] In some embodiments, the heat resistance temperature of the adhesive layer 42 is greater than 170°C. The heat resistance temperature of the adhesive layer 42 is greater than the melting point of the first insulating layer 43 and greater than the melting point of the conductive bonding portion 32. When the first insulating layer 43 melts and bonds with the conductive layer 5 or the battery cell 3, and when the conductive bonding portion 32 melts and connects with the conductive layer 5 and the battery cell 3, the adhesive layer 42 will not melt, thus ensuring the bonding stability between the first insulating layer 43 and the support layer 41.

[0096] As shown in Figures 7 and 8, in this embodiment, the conductive layer 5 is an electroplated metal conductive film or metal foil. For example, the material of the conductive layer 5 includes one or more of gold, silver, copper, and aluminum. When multiple metals are used, the conductive layer 5 is a multilayer structure of multiple metals or a single-layer structure of multiple metal blends. And / or, the thickness of the conductive layer 5 is 15μm to 100μm. For example, the thickness of the conductive layer 5 can be 15μm, 20μm, 30μm, 50μm, 70μm, 80μm, 100μm, etc. The conductive layer 5 made of this material has good toughness during coating and patterning processes and is not easily broken. The thickness of the conductive layer 5 meets the conductivity requirements and reduces costs and the overall thickness and weight of the photovoltaic module, making it less prone to breakage during coating and patterning processes.

[0097] As shown in Figure 6, the ratio of the projected area of ​​the through-hole 44 on the solar cell 3 to the projected area of ​​the conductive connection portion 32 on the solar cell 3 is greater than 1:1 and less than or equal to 50:1. For example, the ratio of their projected areas can be 1.2:1, 1.5:1, 2:1, 3:1, 5:1, 6:1, 8:1, 10:1, 15:1, 20:1, 30:1, 40:1, 50:1, etc. Alternatively, in the extension direction of the sub-gate electrode, the ratio of the maximum width of the conductive connection portion 32 to the width of the through-hole 44 is greater than or equal to 1:100 and less than 1:1. For example, the width ratio can be 1:100, 1:80, 1:60, 1:40, 1:20, 1:10, 1:8, 1:6, 1:5, 1:3, 1:2, 1:1.5, 1:1.2, etc. That is, the conductive joint 32 does not completely fill the through hole 44, but there is a gap, such as a cavity 45, between the conductive joint 32 and the inner wall of the through hole 44. This can prevent the insulating layer 4 and the conductive joint 32 from melting and penetrating into each other's interior, causing short circuits or poor welding. The ratio of their projected areas is not greater than this range or the ratio of their widths is not less than this range. This avoids the conductive joint 32 being too small, ensuring good conductive contact between the conductive joint 32 and the conductive layer 5 and the electrode 31, and avoids the through hole 44 being too large, which would affect the structural strength and insulation support effect of the insulating layer 4.

[0098] For example, the maximum width of the conductive junction is 60μm to 2200μm, specifically 60μm, 80μm, 100μm, 150μm, 300μm, 500μm, 800μm, 1000μm, 1500μm, 2200μm, etc. The width of the via is 1000μm to 6000μm, specifically 1000μm, 1200μm, 1500μm, 2000μm, 2500μm, 3000μm, 3500μm, 4000μm, 4500μm, 5000μm, 6000μm, etc.

[0099] As shown in Figures 1 and 7-9, in some possible implementations, the photovoltaic module further includes a first encapsulation plate 1, a first encapsulating film layer 2, a second encapsulating film layer 6, and a second encapsulation plate 7. The first encapsulating film layer 2 covers the side of the solar cell 3 facing away from the insulating layer 4; the first encapsulation plate 1 covers the side of the first encapsulating film layer 2 facing away from the solar cell 3; the second encapsulating film layer 6 covers the side of the conductive layer 5 facing away from the solar cell 3, and the second encapsulating film layer 6 is filled in the spacer region 53 between adjacent conductive regions of the conductive layer 5, and the second encapsulating film layer 6 in the spacer region 53 is cross-linked with the insulating layer 4; the second encapsulation plate 7 covers the side of the second encapsulating film layer 6 facing away from the solar cell 3; the first encapsulation plate 1 is a transparent plate, and the second encapsulation plate 7 is a transparent or opaque plate. The first encapsulation plate 1 serves as the cover plate of the photovoltaic module for transmitting light, and the second encapsulation plate 7 serves as the backplate of the photovoltaic module, and can be a transparent plate, such as transparent glass or transparent plastic, or an opaque plate.

[0100] With the above technical solution, the first encapsulating layer 2 fixes the position of at least one battery string formed by multiple battery cells 3 onto the first encapsulation plate 1, preventing short circuits and poor appearance caused by displacement of the battery cells 3. As shown in Figure 9, the second encapsulating layer 6 can fill the gaps 34 and string gaps 33 of the battery cells 3 and cross-link with the first insulating layer 43 of the insulating layer 4, improving the fixing effect of the battery cells 3. The second encapsulating layer 6 fixes the conductive layer 5 and the second encapsulation plate 7. The second encapsulating layer 6 fills into the spacing region 53 of the conductive layer 5 and cross-links with the first insulating layer 43 of the insulating layer 4, improving the overall connection strength and reliability of the photovoltaic module. The first encapsulation plate 1 is a transparent plate used to allow light to enter the battery cells 3.

[0101] In this embodiment, the melt crosslinking temperature of the first adhesive layer 2 and the second adhesive layer 6 is T1, the melting point of the first insulating layer 43 is T2, the melting point of the conductive bonding portion 32 is T3, and the melting point of the support layer 41 is T4; wherein, T1 < T2 ≤ T3 < T4. It should be noted that the melt crosslinking temperature is a temperature range, including the melting temperature and the temperature at which crosslinking occurs. The melting temperature is lower than the temperature at which crosslinking occurs. Here, the lower value of the melt crosslinking temperature range can be the melting temperature, and the higher value of the temperature range can be the temperature at which crosslinking occurs. T1 < T2 means that the melting temperature and the crosslinking temperature of the first adhesive layer 2 and the second adhesive layer 6 are both lower than the melting point of the first insulating layer 43. T2 ≤ T3 means that the melting point of the first insulating layer 43 is less than or equal to the melting point of the conductive bonding portion 32. With this setup, during the heating and lamination process, the temperature can be gradually increased. First, the temperature is raised to the lower value of T1, the melting and cross-linking temperature of the first adhesive film layer 2 and the second adhesive film layer 6, i.e., the melting temperature, so that the first adhesive film layer 2 and the second adhesive film layer 6 melt first. Then, the temperature is raised to the higher value of T1, i.e., the cross-linking temperature, so that the first adhesive film layer 2 cross-links and interconnects the battery cell 3 and the first encapsulation plate 1. At the same time, the second adhesive film layer 6 cross-links, so that the conductive layer 5 is bonded and fixed to the second encapsulation plate 7. Afterward, the temperature continues to rise, gradually melting the first insulating layer 43 and the conductive joint 32, avoiding the situation where the conductive joint 32 and the first insulating layer 43 melt and penetrate into each other, causing short circuits or poor soldering, thus improving the insulation effect of the photovoltaic module.

[0102] For example, 70℃≤T1≤110℃; 100℃≤T2≤140℃; 140℃≤T3≤168℃; T4≥250℃. Wherein, 70℃~80℃ is the temperature at which the first adhesive layer 2 and the second adhesive layer 6 begin to melt; 100℃~110℃ is the temperature at which the first adhesive layer 2 and the second adhesive layer 6 undergo cross-linking; and the temperature between these two is the continuous melting temperature. 100℃~110℃ is the temperature at which the first insulating layer 43 begins to melt; 110℃~140℃ is the temperature at which the first insulating layer 43 continues to melt. 140℃~150℃ is the temperature at which the conductive bonding portion 32 begins to melt; 150℃~168℃ is the temperature at which the conductive bonding portion 32 continues to melt; and above 250℃ is the melting temperature of the support layer 41. As the temperature gradually increases during the heating and lamination process, the melting of each layer and the establishment of an adhesive relationship are gradually achieved.

[0103] Based on the photovoltaic modules described in any of the above embodiments, this application also provides a method for manufacturing photovoltaic modules, including the following steps:

[0104] Step S100 involves providing a solar cell 3, an insulating layer 4, and a patterned conductive layer 5. The solar cell 3 has an electrode 31 on its back side. The insulating layer 4 has a through-hole 44 extending along its thickness direction. The insulating layer 4 includes a support layer 41 and a first insulating layer 43, which are disposed on opposite sides of the support layer 41 along its thickness direction. The conductive layer 5 has conductive regions. The specific structures of the electrode 31, through-hole 44, and conductive layer 5 can be found in the description of the photovoltaic module embodiments described above, and will not be repeated here.

[0105] In step S200, the conductive bonding portion 32 is printed on the electrical connection portion of the electrode 31 of the battery cell 3 or on the corresponding via 44 position of the conductive area of ​​the conductive layer 5. For example, the conductive bonding portion 32 can be printed on the pad, the thickened section of the sub-gate electrode, or the electrical connection point of the sub-gate electrode.

[0106] In step S300, as shown in Figure 3, the battery cell 3, the insulating layer 4, and the conductive layer 5 are stacked sequentially. The through hole 44 exposes at least part of the electrical connection portion and the conductive area of ​​the electrode 31. The conductive bonding portion 32 is located inside the through hole 44 and is in contact with the electrical connection portion and the conductive area of ​​the electrode 31.

[0107] For example, the battery cell 3 with the conductive bonding portion 32 printed on it can be evenly arranged on the conductive layer 5 using a high-precision typesetting machine, or the battery cell 3 can be evenly arranged on the conductive layer 5 with the conductive bonding portion 32 printed on it using a high-precision typesetting machine, so that the through hole 44 corresponds one-to-one with the electrical connection portion, and the conductive bonding portion 32 in a part of the through hole 44 contacts the positive electrode and the first conductive area 51 respectively, and the conductive bonding portion 32 in another part of the through hole 44 contacts the negative electrode and the second conductive area 52 respectively.

[0108] During this process, the battery cell 3 can be heated by the heating module, so that the battery cell 3 is pre-bonded to the first insulating layer 43 on one side of the insulating layer 4. By adjusting the temperature of the heating module, the conductive joint 32 can also be melted and interconnected with the conductive layer 5, further fixing the position of the battery cell 3. At this time, the thickness h1 of the conductive joint 32 is in the range of 50μm to 1500μm, the diameter d1 is in the range of 50μm to 2000μm, and the thickness h3 of the insulating layer 4 is in the range of 25mm to 300mm.

[0109] .

[0110] In step S400, as shown in Figures 4-6, heating and lamination are performed to expel the gas between the battery cell 3, insulating layer 4, conductive layer 5, and conductive bonding portion 32. This causes the first insulating layer 43 on both opposite sides of the insulating layer 4 to melt and bond to the battery cell 3 and conductive layer 5 respectively. The first insulating layer 43 melts and covers the side surface of the support layer 41 near the through hole 44. The conductive bonding portion 32 melts and bonds to the electrical connection portion and conductive area of ​​the electrode 31. Furthermore, in some cases, a cavity 45 with a first vacuum degree can be formed between the conductive bonding portion 32 and the inner wall of the through hole 44. For example, the laminated component is placed inside the laminator cavity, and gas is expelled during the lamination process.

[0111] With the above technical solution, the photovoltaic module described in the above embodiment can be obtained through this preparation method. Since the insulating layer 4 is bonded and fixed to the cell 3 and conductive layer 5 respectively by the first insulating layer 43 on both sides, it serves both insulating and fixing functions. The support layer 41 provides support for the insulating layer 4, making it less likely that the insulating layer 4 will deform significantly due to heat, thus reducing the alignment accuracy between the insulating layer 4 and the cell 3 and conductive layer 5. Furthermore, during the lamination process, the first insulating layer 43 covers the side surface of the support layer 41 near the through-hole 44; that is, the inner wall of the through-hole 44 is the first insulating layer 43, and the support layer 41 is wrapped by the first insulating layer 43. The gaps between the layers of the insulating layer 4 are sealed by the first insulating layer, thereby ensuring the sealing performance of the insulating layer 4. Moisture is less likely to enter the interior of the photovoltaic module through the insulating layer 4, improving the corrosion resistance of the photovoltaic module and reducing the impact of moisture on the insulation effect. Furthermore, because there is a gap between the inner wall of the through hole 44 on the insulating layer 4 and the conductive joint 32 located in the through hole 44, and because the insulating layer 4 has low fluidity after melting and bonding with the conductive layer 5 and the battery cell 3, it will not come into contact with the conductive joint 32. Thus, after lamination, a cavity 45 is formed, and the conductive joint 32 does not come into contact with the insulating layer 4. The conductive joint 32 is less likely to melt and penetrate into the insulating layer 4, connecting with the opposite electrode or conductive area and causing a short circuit. The first insulating layer 43 of the insulating layer 4 is also less likely to melt and penetrate into the interior of the conductive joint 32, causing the conductive joint 32 to be poorly welded. This improves the insulation effect of the photovoltaic module.

[0112] In some embodiments, in step S200, the ratio of the projected area of ​​the printed conductive bonding portion 32 on the battery cell 3 to the projected area of ​​the through hole 44 on the battery cell 3 is greater than or equal to 1:50 and less than 1:1, preferably greater than or equal to 1:50 and less than 1:1. Specifically, this ratio can be 1:8, 1:6, 1:4, 1:3, 1:2, 1:1.5, 1:1.2, etc. Alternatively, in the extension direction of the sub-gate electrode, the ratio of the maximum width of the printed conductive bonding portion 32 to the width of the through hole 44 is greater than or equal to 1:100 and less than 1:1. For example, the width ratio can be 1:100, 1:80, 1:60, 1:40, 1:20, 1:10, 1:8, 1:6, 1:5, 1:3, 1:2, 1:1.5, 1:1.2, etc. That is, when the conductive joint 32 is printed, it does not completely fill the through hole 44. Instead, there is a gap between the conductive joint 32 and the inner wall of the through hole 44. This can prevent the insulating layer 4 and the conductive joint 32 from melting and penetrating into each other's interior during the lamination process, which would cause short circuits or poor soldering and form cavities 45. The area ratio is not less than this range, which avoids the conductive joint 32 being printed too small and ensures good conductive contact between the conductive joint 32 and the conductive layer 5 and the electrode 31.

[0113] In some embodiments, the melting point of the first insulating layer 43 is T2, the melting point of the conductive bonding portion 32 is T3, and the melting point of the support layer 41 is T4; wherein, T2≤T3<T4. T2≤T3 indicates that the melting temperature of the first insulating layer 43 is less than or equal to the melting temperature of the conductive bonding portion 32.

[0114] The heating and lamination process in step S400 specifically includes the following steps:

[0115] In step S401, the temperature is raised to T2 during the lamination process, causing the first insulating layer 43 to melt, so that the first insulating layer 43 is bonded and fixed to the conductive layer 5 and the battery cell 3, and the first insulating layer 43 melts and covers the side surface of the support layer 41 near the through hole 44.

[0116] In step S402, the temperature is raised to T3, causing the conductive bonding portion 32 to melt and adhere to the conductive area and the electrical connection portion of the electrode 31. In some cases, a cavity 45 can also be formed between the conductive bonding portion 32 and the inner wall of the through hole 44. After cooling, the photovoltaic module structure shown in Figure 6 is obtained. Further, the first insulating layer 43 covering the side surface of the support layer 41 near the through hole 44 has the protruding structure shown in Figure 6. At this time, due to the evaporation of the solvent in the conductive bonding portion 32 and the change in density, the volume of the conductive bonding portion 32 changes under the action of pressure. At this time, the thickness h2 of the conductive bonding portion 32 ranges from 25μm to 1450μm, and the diameter d2 ranges from 60μm to 2200μm. The thickness of the insulating layer 4 also changes due to the melting and flow, with the thickness h4 ranging from 15μm to 250μm, as shown in Figures 4 and 5.

[0117] With the above technical solution, during the heat lamination process, the temperature can be gradually increased, allowing the first insulating layer 43 to melt first and establish a bond with the conductive layer 5 and the battery cell 3. At this time, the conductive bonding portion 32 has not yet melted, so it will not flow into the insulating layer 4 and affect the insulation effect of the insulating layer 4. Subsequently, as the temperature continues to rise, the conductive bonding portion 32 begins to melt and establish a bond with the conductive layer 5 and the electrode 31. After cooling, the conductive bonding portion 32 solidifies, preventing the insulating layer 4 and the conductive bonding portion 32 from intruding into each other and affecting the insulation and welding effects. Because the support layer 41 has a high melting temperature, it will not melt or deform during the heat lamination process, thus improving the support and insulation effect of the insulating layer 4.

[0118] Furthermore, in this embodiment, the provision of the battery cell 3, insulating layer 4, and patterned conductive layer 5 in step S100 further includes: providing a first adhesive film layer 2, a second adhesive film layer 6, a first encapsulation plate 1, and a second encapsulation plate 7, wherein the insulating layer 4, conductive layer 5, second adhesive film layer 6, and second encapsulation plate 7 are sequentially stacked to form an integrated conductive backplate A, as shown in Figure 1. The insulating layer 4 can be pre-fixed to the conductive layer 5 by tape or heat-pressing. The integrated conductive backplate A can be obtained by laminating multiple layers of materials using a coating and laminating equipment in a roll-to-roll manner, or by first cutting and patterning the materials in roll-to-sheet manner, then stacking them, and finally heat-pressing the multiple layers of materials into a sheet.

[0119] Meanwhile, step S300, which involves sequentially stacking the battery cell 3, the insulating layer 4, and the conductive layer 5, specifically includes the following steps:

[0120] In step S301, the battery cell 3 and the integrated conductive backplate A are stacked and pre-fixed in sequence, wherein the through hole 44 at least partially exposes the electrical connection part and conductive area of ​​the electrode 31, and the conductive joint part 32 is located in the through hole 44 and contacts the electrical connection part and conductive area of ​​the electrode 31.

[0121] For example, the battery cells 3 with printed conductive joints 32 can be evenly arranged on the conductive layer 5 of the integrated conductive backplate A using a high-precision layout machine, or the battery cells 3 can be evenly arranged on the conductive layer 5 of the integrated conductive backplate A with printed conductive joints 32 using a high-precision layout machine, so that the through holes 44 correspond one-to-one with the electrical connections. The conductive joints 32 in some of the through holes 44 are in contact with the positive electrode electrical connection and the first conductive area 51, respectively, and the conductive joints 32 in other through holes 44 are in contact with the negative electrode electrical connection and the second conductive area 52, respectively.

[0122] During this process, the battery cell 3 can be heated by the heating module, so that the battery cell 3 is pre-bonded and fixed to the first insulating layer 43 on one side of the insulating layer 4. By adjusting the temperature of the heating module, the conductive joint 32 can also be melted and interconnected with the conductive layer 5, further fixing the position of the battery cell 3.

[0123] In step S302, the first adhesive film layer 2 is laid on the side of the battery cell 3 facing away from the insulating layer 4. At this time, the side of the battery cell 3 facing away from the insulating layer 4 is facing upwards, and the first adhesive film layer 2 is laid on the battery cell 3.

[0124] Step S303: The first encapsulation plate 1 is laid on the side of the first adhesive film layer 2 facing away from the battery cell 3 to obtain the laminate to be laminated.

[0125] Meanwhile, the heating and lamination in step S400 specifically includes the following steps: heating and laminating the first encapsulation plate 1, the first adhesive film layer 2, the battery cell 3, and the integrated conductive backplate A, so that the first adhesive film layer 2 melts and is bonded and fixed to the first encapsulation plate 1 and the battery cell 3, so that the second adhesive film layer 6 melts and is bonded and fixed to the second encapsulation plate 7 and the conductive layer 5, and so that the second adhesive film layer 6 melts and flows into the spacer region 53 between adjacent conductive regions of the conductive layer 5 and is cross-linked and fixed to the first insulating layer 43, so that the first insulating layer 43 on both sides of the insulating layer 4 melts and is bonded and fixed to the battery cell 3 and the conductive layer 5 respectively, so that the first insulating layer 43 is cross-linked with the first adhesive film layer 2, so that the first insulating layer 43 melts and covers the side surface of the support layer 41 near the through hole 44, so that the conductive joint 32 melts and is bonded and fixed to the electrode 31 and the conductive region. In some cases, a cavity 45 with a first vacuum degree can also be formed between the conductive joint 32 and the inner wall of the through hole 44.

[0126] When the above technical solution is adopted, the insulating layer 4, the conductive layer 5, the second adhesive film layer 6, and the second encapsulation plate 7 are stacked into an integrated conductive backplate A. As a whole, it is convenient to arrange and combine with the battery cell 3, which simplifies the process. The first adhesive film layer 2, the second adhesive film layer 6 and the insulating layer 4 are cross-linked, which improves the insulation effect and the firmness of the fixation.

[0127] Furthermore, in this embodiment, the melt crosslinking temperature of the first adhesive film layer 2 and the second adhesive film layer 6 is T1, where T1 < T2 ≤ T3 < T4;

[0128] Therefore, the heating and lamination process in step S401, before heating to T2 during the lamination process, further includes the following steps:

[0129] During the lamination process, the temperature is raised to T1, causing the first adhesive film layer 2 to melt and bond with the battery cell 3 and the first encapsulation plate 1, and causing the second adhesive film layer 6 to melt and bond with the conductive layer 5 and the second encapsulation plate 7. The second adhesive film layer 6 melts and flows into the spacer region 53 between adjacent conductive regions of the conductive layer 5 and crosslinks with the first insulating layer 43.

[0130] With the above technical solution, during the heating and lamination process, the temperature can be gradually increased. First, the temperature is increased to the melting and cross-linking temperature T1 of the first adhesive film layer 2 and the second adhesive film layer 6, so that the first adhesive film layer 2 melts and interconnects with the conductive layer 5 and the second encapsulation plate 7. At the same time, the second adhesive film layer 6 melts and cross-links, so that the battery cell 3 is bonded and fixed to the first encapsulation plate 1. Then, the temperature continues to rise, gradually melting the first insulating layer 43 and the conductive joint 32. This avoids the conductive joint 32 from penetrating into each other after melting and causing short circuits or poor soldering, thereby improving the insulation effect of the photovoltaic module.

[0131] For example, 70℃≤T1≤110℃; 100℃≤T2≤140℃; 140℃≤T3≤168℃; T4≥250℃. Here, 70℃~80℃ is the temperature at which the first adhesive layer 2 and the second adhesive layer 6 begin to melt; 100℃~110℃ is the temperature at which cross-linking can occur between the first adhesive layer 2 and the second adhesive layer 6; and the temperature between these two is the continuous melting temperature. 100℃~110℃ is the temperature at which the first insulating layer 43 begins to melt; 110℃~140℃ is the continuous melting temperature of the first insulating layer 43. 140℃~150℃ is the temperature at which the conductive bonding portion 32 begins to melt; 150℃~168℃ is the continuous melting temperature of the conductive bonding portion 32; and above 250℃ is the melting temperature of the support layer 41. As the temperature gradually increases during the heating and lamination process, the layers gradually melt and establish an adhesive relationship.

[0132] This embodiment provides a specific process for manufacturing a photovoltaic module:

[0133] The first step, as shown in Figure 3, is to print the conductive bonding portion 32 on the electrode 31 of the battery cell 3, and then use a high-precision typesetting machine to evenly arrange the battery cells 3 with the printed conductive bonding portion 32 on the insulating layer 4 of the integrated conductive backplate A; or the conductive bonding portion 32 is printed on the conductive layer 5 corresponding to the through hole 44 of the insulating layer 4 of the integrated conductive backplate A, and then use a high-precision typesetting machine to evenly arrange the battery cells 3 on the insulating layer 4 of the integrated conductive backplate A, with the electrical connection portion of the electrode 31 corresponding one-to-one with the through hole 44 of the integrated conductive backplate A.

[0134] The second step, as shown in Figure 3, involves heating the battery cell 3 using a heating module to bond and fix the battery cell 3 to the first insulating layer 43 of the insulating layer 4, thereby fixing the battery cell 3 and preventing short circuits, failures, or other defects caused by movement at subsequent work stations. Alternatively, adjusting the temperature of the heating module can simultaneously melt the conductive joint 32 and interconnect it with the conductive layer 5, further fixing the position of the battery cell 3. At this time, the thickness h1 of the conductive joint 32 ranges from 50μm to 1500μm, the diameter d1 ranges from 50μm to 2000μm, and the thickness h3 of the insulating layer 4 ranges from 25mm to 300mm.

[0135] The third step is to lay the first adhesive film layer 2 on top of the battery cell 3, and then lay the first encapsulation plate 1 on top of the first adhesive film layer 2 to obtain the laminate to be laminated.

[0136] The fourth step involves feeding the stacked components into the laminator via an assembly line. Vacuuming is performed inside the laminator chamber to expel gas, while heating and pressurization cause cross-linking between materials. At this point, the second adhesive film layer 6, with its lower melting point, begins to melt at a lamination temperature of 70°C, and then cross-links at 105°C, interconnecting the second encapsulation plate 7 with the conductive layer 5. The melted adhesive film layer 6 flows into the spacer region 53 between adjacent conductive areas of the conductive layer 5 and cross-links with and fixes to the first insulating layer 43, as shown in Figure 8. Simultaneously, the first adhesive film layer 2 also melts at a lamination temperature of 70°C, and then cross-links at 105°C, fixing the front side of the battery cell 3 to one side of the first encapsulation plate 1.

[0137] The fifth step, as shown in Figure 4, involves further heating. The first insulating layer of the insulating layer begins to melt when the temperature reaches 110°C, and cross-links are generated when the temperature reaches 140°C, interconnecting with the conductive layer and the battery cell. This causes the first insulating layer to melt and cover the side surface of the support layer near the through hole, as shown in Figure 5.

[0138] Step 6: Continue heating. When the lamination temperature reaches above 140°C, the conductive bonding portion begins to melt and interconnects with the first and second conductive regions of the conductive layer and the electrodes of the battery cell. The lamination temperature is adjusted according to the melting temperature of the conductive bonding portion 32, with a lamination temperature range of 140–200°C, preferably 145–175°C; the pressure range is 0–55 kPa; and the lamination time range is 20–35 min, preferably 25 min in this embodiment. After lamination, the conductive bonding portion 32 solidifies while cooling, forming the structure shown in Figure 6. Furthermore, the first insulating layer 43 covering the surface of the support layer 41 near the through hole 44 has the protruding structure shown in Figure 6. At this point, due to solvent evaporation and density changes in the conductive joint 32, its volume changes under pressure. The thickness h2 of the conductive joint 32 then ranges from 25 μm to 1450 μm, and its diameter d2 ranges from 60 μm to 2200 μm. The thickness of the insulating layer also changes due to the melting and flow, with the thickness h4 ranging from 15 μm to 250 μm, as shown in Figures 4 and 5. Current can be transmitted through the cured conductive joint 32 to the conductive layer 5, and then further transmitted to the outside via the connector.

[0139] The seventh step involves framing the laminated components, installing connectors, and cleaning them to complete the component manufacturing process.

[0140] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0141] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A photovoltaic module, wherein, include: A battery cell, wherein the back side of the battery cell has electrodes; An insulating layer is disposed on the back side of the battery cell. The insulating layer has a through hole extending along its thickness direction. The through hole is used to at least partially expose the electrical connection portion of the electrode. The insulating layer includes a support layer and a first insulating layer. The first insulating layer is disposed on two opposite sides of the support layer in the thickness direction, and the first insulating layer covers the side surface of the support layer near the through hole at the through hole. A patterned conductive layer is disposed on the side of the insulating layer opposite to the battery cell, and the conductive layer has conductive regions; A conductive joint is located within the through hole, and the conductive joint is electrically connected to the electrical connection and the conductive area.

2. The photovoltaic module according to claim 1, wherein, A cavity is formed between the conductive joint and the inner wall of the through hole.

3. The photovoltaic module according to claim 2, wherein, The cavity has a first degree of vacuum.

4. The photovoltaic module according to claim 1, wherein, In the thickness direction of the insulating layer, the non-edge portion of the first insulating layer covering the side surface of the support layer at the through hole protrudes toward the through hole.

5. The photovoltaic module according to claim 4, wherein, Along the direction from the edge of the first insulating layer on the side surface of the support layer to the non-edge portion, the distance by which the first insulating layer protrudes into the through hole gradually increases.

6. The photovoltaic module according to claim 1, wherein, Along the direction from the conductive layer to the battery cell, the first insulating layer covering the side surface of the support layer at the through hole gradually protrudes into the through hole.

7. The photovoltaic module according to claim 6, wherein, Along the direction from the conductive layer to the battery cell, the first insulating layer covering the side surface of the support layer is curved.

8. The photovoltaic module according to any one of claims 1-7, wherein, The melting point of the first insulating layer is T2, the melting point of the conductive joint is T3, and the melting point of the support layer is T4; Where T2≤T3<T4.

9. The photovoltaic module according to any one of claims 1-7, wherein, The material of the first insulating layer includes one or more of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, and vinyl chloride; And / or, the thickness of the first insulating layer located on opposite sides of the support layer in the thickness direction is 18 μm to 200 μm.

10. The photovoltaic module according to any one of claims 1-7, wherein, The support layer includes a polymer film or a composite material layer; The polymer film is made of one or more of polyethylene terephthalate and polyimide. The composite material layer is made of resin and fillers, and the fillers include one or more of carbon fiber, glass fiber, glass wool, talc, graphene, and mica sheets. And / or, the thickness of the support layer is 18μm to 300μm.

11. The photovoltaic module according to any one of claims 1-7, wherein, The insulating layer further includes an adhesive layer located between the support layer and the first insulating layer; The adhesive layer is made of one or more of polyurethane and acrylic. And / or, the heat resistance temperature of the adhesive layer is greater than 170°C.

12. The photovoltaic module according to any one of claims 1-7, wherein, The conductive layer is an electroplated metal conductive film or a metal foil; And / or, the conductive layer is made of one or more of gold, silver, copper, and aluminum; And / or, the thickness of the conductive layer is 15μm to 100μm.

13. The photovoltaic module according to any one of claims 1-7, wherein, The ratio of the projected area of ​​the through hole on the battery cell to the projected area of ​​the conductive joint on the battery cell is greater than 1:1 and less than or equal to 50:

1.

14. The photovoltaic module according to any one of claims 1-7, wherein, In the extending direction of the sub-gate electrode, the ratio of the maximum width of the conductive joint to the width of the through hole is greater than or equal to 1:100 and less than 1:

1.

15. The photovoltaic module according to any one of claims 1-7, wherein, The photovoltaic module further includes a first encapsulation plate, a first adhesive film layer, a second adhesive film layer, and a second encapsulation plate; The first adhesive film layer covers the side of the battery cell that is away from the insulating layer; The first encapsulation plate covers the side of the first adhesive film layer that is opposite to the battery cell; The second adhesive film layer covers the side of the conductive layer opposite to the battery cell, and the second adhesive film layer is filled in the space between adjacent conductive areas of the conductive layer, and the second adhesive film layer in the space is cross-linked with the insulating layer. The second encapsulation plate covers the side of the second adhesive film layer that is opposite to the battery cell; The first encapsulation board is a transparent board, and the second encapsulation board is either a transparent board or an opaque board.

16. The photovoltaic module according to claim 15, wherein, The melting crosslinking temperature of the first adhesive film layer and the second adhesive film layer is T1, the melting point of the first insulating layer is T2, the melting point of the conductive joint is T3, and the melting point of the support layer is T4. Where T1 < T2 ≤ T3 < T4.

17. The photovoltaic module according to claim 16, wherein, 70℃≤T1≤110℃; 100℃≤T2≤140℃; 140℃≤T3≤168℃; T4≥250℃.

18. The photovoltaic module according to any one of claims 1-7, wherein, The thickness of the conductive joint is 25 μm to 1450 μm; and / or the diameter of the conductive joint is 60 μm to 2200 μm; and / or the thickness of the insulating layer is 15 μm to 250 μm.

19. A method for manufacturing a photovoltaic module, wherein, include: A battery cell, an insulating layer, and a patterned conductive layer are provided. The back side of the battery cell has an electrode. The insulating layer has a through hole extending along its thickness direction. The insulating layer includes a support layer and a first insulating layer. The first insulating layer is disposed on two opposite sides of the support layer in the thickness direction. The conductive layer has a conductive region. The conductive bonding portion is printed on the electrical connection portion of the electrode or printed on the conductive area of ​​the conductive layer at the position corresponding to the through hole; The battery cell, the insulating layer, and the conductive layer are stacked sequentially, wherein the through hole at least partially exposes the electrical connection portion and the conductive area, and the conductive bonding portion is located within the through hole and contacts the electrical connection portion and the conductive area; Heating and laminating releases the gas between the battery cell, the insulating layer, the conductive layer, and the conductive bonding portion, causing the first insulating layer on both opposite sides of the insulating layer to melt and bond to the battery cell and the conductive layer respectively, causing the first insulating layer to melt and cover the side surface of the support layer near the through hole, and causing the conductive bonding portion to melt and bond to the electrical connection portion and the conductive area.

20. The method for preparing a photovoltaic module according to claim 19, wherein, The melting point of the first insulating layer is T2, the melting point of the conductive joint is T3, and the melting point of the support layer is T4; wherein, T2≤T3<T4; The heating and lamination process includes: During the lamination process, the temperature is raised to T2, causing the first insulating layer to melt and bond with the conductive layer and the battery cell, and causing the first insulating layer to melt and cover the side surface of the support layer near the through hole; The temperature is raised to T3, causing the conductive joint to melt and adhere to and fix the conductive area and the electrical connection.

21. The method for preparing a photovoltaic module according to claim 20, wherein, The provision of the battery cell, insulating layer and patterned conductive layer further includes providing a first adhesive film layer, a second adhesive film layer, a first encapsulation plate and a second encapsulation plate, wherein the insulating layer, the conductive layer, the second adhesive film layer and the second encapsulation plate are sequentially stacked to form an integrated conductive backplane; The step of sequentially stacking the battery cell, the insulating layer, and the conductive layer includes: The battery cells and the integrated conductive backplate are stacked and pre-fixed in sequence; The first adhesive film layer is laid on the side of the battery cell that is away from the insulating layer; The first encapsulation plate is laid on the side of the first adhesive film layer that is away from the battery cell; The heating and lamination process includes heating and laminating the first encapsulation plate, the first adhesive film layer, the battery cell, and the integrated conductive backsheet.

22. The method for preparing a photovoltaic module according to claim 21, wherein, The melt crosslinking temperatures of the first adhesive film layer and the second adhesive film layer are T1, where T1 < T2 ≤ T3 < T4; Before heating to T2 during the lamination process, the heating and lamination process further includes: During the lamination process, the temperature is raised to T1, causing the first adhesive film layer to melt and bond to the battery cell and the first encapsulation plate, and causing the second adhesive film layer to melt and bond to the conductive layer and the second encapsulation plate, and causing the second adhesive film layer to melt and flow into the spacer area between the conductive areas of the conductive layer and crosslink and fix to the first insulating layer.

23. The method for preparing a photovoltaic module according to claim 22, wherein, 70℃≤T1≤110℃; 100℃≤T2≤140℃; 140℃≤T3≤168℃; T4≥250℃.

24. The method for manufacturing a photovoltaic module according to any one of claims 19-23, wherein, The ratio of the projected area of ​​the printed conductive bonding portion on the battery cell to the projected area of ​​the through hole on the battery cell is greater than or equal to 1:50 and less than 1:1.

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