Carrier film and photovoltaic module

Abstract

The invention provides a carrier film and a photovoltaic module, the carrier film comprises a first bonding layer, the upper surface of the first bonding layer is provided with a rigid layer or a plurality of rigid bodies are dispersed in the first bonding layer, if the upper surface of the first bonding layer is provided with the rigid layer, the thickness d of the first bonding layer is within the following range: d1 < = d < = phi, wherein d1 = (L0-phi) * (phi / 2 + h) / L0 + 2 * (2a + phi) * h / L0-pi phi / 2 * (90 degrees-beta) / (360 degrees * L0), h = phi / 2 * cos beta, a = (phi / 2) 2 * sin beta, beta < = 90 degrees or d1 = (L0-phi) * (phi / 2 * cos beta) / L0, beta > 90 degrees; if a plurality of rigid bodies are dispersed in the first bonding layer, the first bonding layer meets the formula: E = PL0 / (pi phi / 2 + phi). According to the invention, the bearing film improves the contact performance of the welding strip and the battery piece, thereby improving the conductive efficiency.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of photovoltaic modules and their encapsulation technologies, and particularly relates to a carrier film and a photovoltaic module. Background Art

[0002] The encapsulation technology of photovoltaic modules has evolved from the earliest two main grids to three main grids, five main grids, six main grids, and now to MBB (Multi - Busbar) and SMBB (Super Multi - Busbar). The number of main grid lines is increasing and getting thinner, so the amount of silver paste used is decreasing, which can achieve rapid cost reduction of the modules. In the future, the ultimate choice in the industry is not more main grids, but the 0BB (Zero Busbar) solution with zero main grids. The 0BB technology eliminates the main grids in photovoltaic cells and uses thinner solder ribbons to directly replace and connect the fine grids to collect and export current. This design significantly reduces the metal shading area on the backplane of the cell, increases the light - receiving area, and thus improves the power generation efficiency of the photovoltaic panel.

[0003] The change from multi - main grids to 0BB is essentially an electrode change. The metal electrodes on the front and back of the cell are used to export the internal current, which can be divided into main grids and sub - grids. Among them, the main grid mainly plays the role of collecting the current of the sub - grids, forming a weld with the solder ribbon, and completing the series connection. The sub - grid is used to collect photo - generated carriers. 0BB means eliminating the main grid in the cell link and using the solder ribbon to export current in the module link, which can reduce silver and reduce shading, thus reducing costs and increasing efficiency. In addition, the wafer thinning technology is also continuously progressing, and the cell with a thickness within 100 microns has been broken through and will be commercialized. Therefore, "zero main grid and wafer thinning" is a better path for "cost reduction and efficiency increase". The integrated film covering (IFC) technology is a process method in which the solder ribbon is pressed onto the cell through a glue film to initially form a series connection, and then low - temperature lamination is used for welding. The film covering the surface of this cell is called the carrier film.

[0004] Currently, the main function of the carrier film in the industry is to prevent the conventional encapsulation glue film from penetrating under the solder ribbon, and it has a pressing effect on the solder ribbon. However, the ability of this carrier film to withstand thermal shock and mechanical shock is poor. For the pre - crosslinked carrier film with better use effect, in order to improve the pressing effect, the degree of pre - crosslinking is increased, thus sacrificing most of the bonding ability and increasing the proportion of process bubbles. And in special environments such as hot spots, the creep of the glue film and stress release cause the glue film to shrink inward to form voids, solder re - distribution, and solder wire loosening, resulting in welding failure. Some carrier films have poor mechanical strength and are not strong enough to press and cover the deformation of the solder ribbon end, resulting in poor contact between the solder ribbon and the cell, and the end connection failure after TC (thermal cycle test). There is also the problem that the thickness control of the bonding layer is not in place and the amount of glue is too much, causing the glue film to flow under the solder ribbon during lamination, resulting in failure. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a carrier film and a photovoltaic module, which can improve the contact performance between the solder tape and the cell, and thus improve the conduction efficiency.

[0006] To solve the above technical problem, in the first aspect, the present invention provides a carrier film, including: a first adhesive layer, on the upper surface of the first adhesive layer there is a rigid layer or a number of rigid bodies are dispersed in the first adhesive layer; if there is a rigid layer on the upper surface of the first adhesive layer, the thickness d of the first adhesive layer is in the following range: d1≤d≤φ; where, d1=(L0 - φ)*(φ / 2 + h) / L0 + 2*(2a + φ)*h / L0 - πφ / 2*(90° - β) / (360°*L0), h = φ / 2*cosβ, a=(φ / 2)2*sinβ, β≤90°; or d1=(L0 - φ)*(φ / 2*cosβ) / L0, β>90°; if a number of rigid bodies are dispersed in the first adhesive layer, the first adhesive layer satisfies: E = PL0 / (πφ / 2 + φ); in the formula, φ is the diameter of the solder tape without including the solder layer; d1 is the minimum thickness of the first adhesive layer; L0 is the axial center distance between adjacent two solder tapes; P is the lamination pressure; E is the Young's modulus of the first adhesive layer; β is the central angle between the intersection point of the bottom surface of the rigid layer and the solder tape and the vertex of the solder tape on the longitudinal section of the solder tape.

[0007] Optionally, the melting point of the first adhesive layer is 25°C to 120°C.

[0008] Optionally, the first adhesive layer is made of one or more of the following materials: high melt index EVA, acrylic acid, PVB, TPO, polyurethane, silicone, epoxy resin, and polyolefin.

[0009] Optionally, the strain of the rigid layer is greater than φ(π + 2) / 2L0.

[0010] Optionally, the material of the rigid layer is polymer or transparent inorganic substance, or the material of the rigid layer is one or more of PET, epoxy resin, polyurethane, hard plastic, thermoplastic, elastomer, and thermoplastic elastomer.

[0011] Optionally, the number of rigid bodies is a continuous structure or a discontinuous structure, and is uniformly dispersed in the first adhesive layer.

[0012] Optionally, when the number of rigid bodies is a discontinuous structure, the shape of the number of rigid bodies is powder, powder sheet, and / or powder wire shape, and the material of the number of rigid bodies is one or more of the following: PET, epoxy resin, polyurethane, hard plastic, thermoplastic, elastomer, thermoplastic elastomer, and glass.

[0013] Optionally, when the plurality of rigid bodies are continuous structures, the material of the plurality of rigid bodies is glass fiber, fiber and / or hard plastic wire.

[0014] Optionally, the plurality of rigid bodies are arranged in an orderly manner along the same direction.

[0015] Optionally, it further includes a second adhesive layer, the second adhesive layer is located on the upper surface of the rigid layer, and the melting point of the second adhesive layer is between 100°C and 150°C.

[0016] Optionally, it further includes a barrier layer, and the barrier layer is on the upper surface of the first adhesive layer or on the upper surface of the rigid layer.

[0017] Optionally, the porosity range of the rigid layer is 5% to 90%.

[0018] In a second aspect, the present invention provides a photovoltaic module, including a front glass, a front EVA, a front carrier film, a solder ribbon, a battery cell, a back carrier film, a back adhesive film, and a back glass connected in sequence, wherein the front carrier film and the back carrier film adopt the carrier film as described in the first aspect.

[0019] Optionally, the battery cell is a main-gridless battery cell.

[0020] Compared with the prior art, the present invention has the following advantages: The carrier film includes a first adhesive layer, and the upper surface of this layer has a rigid layer or a plurality of rigid bodies are dispersed in this layer. If the upper surface of the first adhesive layer has a rigid layer, the thickness d of the first adhesive layer is in the following range: d1 ≤ d ≤ φ; where, d1 = (L0 - φ) * (φ / 2 + h) / L0 + 2 * (2a + φ) * h / L0 - πφ / 2 * (90° - β) / (360° * L0), h = φ / 2 * cosβ, a = (φ / 2)2 * sinβ, β ≤ 90°; or d1 = (L0 - φ) * (φ / 2 * cosβ) / L0, β > 90°; if a plurality of rigid bodies are dispersed in the first adhesive layer, the first adhesive layer satisfies: E = PL0 / (πφ / 2 + φ), and this carrier film improves the contact performance between the solder ribbon and the battery cell, thereby improving the conduction efficiency. Description of the Drawings

[0021] The inclusion of the drawings is to provide a further understanding of the present application. They are incorporated and constitute a part of the present application. The drawings show embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the drawings:

[0022] Figure 1 is a schematic structural diagram of a carrier film according to an embodiment of the present invention;

[0023] Figure 2Schematic diagram of the use effect of the carrier film (including the rigid layer) in an embodiment of the present invention;

[0024] Figure 3 Schematic diagram for calculating the minimum thickness of the first adhesive layer in an embodiment of the present invention, β ≤ 90°;

[0025] Figure 4 Schematic diagram for calculating the minimum thickness of the first adhesive layer in an embodiment of the present invention, β > 90°;

[0026] Figure 5 Schematic diagram of the use effect of the carrier film (including the rigid body) in an embodiment of the present invention;

[0027] Figure 6 One structural form of the rigid body in an embodiment of the present invention;

[0028] Figure 7 Another structural form of the rigid body in an embodiment of the present invention;

[0029] Figure 8 Yet another structural form of the rigid body in an embodiment of the present invention;

[0030] Figure 9 Schematic diagram of the structure of another carrier film in an embodiment of the present invention;

[0031] Figure 10 Schematic diagram of the structure of yet another carrier film in an embodiment of the present invention;

[0032] Figure 11 Schematic diagram of the structure of a photovoltaic module in an embodiment of the present invention.

[0033] In the figure:

[0034] 10 - Carrier film;

[0035] 110 - First adhesive layer;

[0036] 120 - Rigid layer;

[0037] 130 - Second adhesive layer;

[0038] 140 - Barrier layer;

[0039] 20 - Front glass;

[0040] 30 - Front adhesive film;

[0041] 40 - Welding tape, 401 - Solder layer;

[0042] 50 - Solar cell;

[0043] 60 - Back adhesive film

[0044] 70 - Back glass. Detailed implementation manners

[0045] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the figures represent the same structure or operation.

[0046] For the sake of convenience of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the accompanying drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0047] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above terms have no special meanings, and thus cannot be construed as limiting the protection scope of the present application. In addition, although the terms used in the present application are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of the present description. In addition, it is required to understand the present application not only through the actual terms used, but also through the meanings implied by each term.

[0048] Referring to Figure 1 as shown, this embodiment provides a carrier film 10, including a first adhesive layer 110. The upper surface of the first adhesive layer 110 has a rigid layer 120 or a number of rigid bodies are dispersed in the first adhesive layer 110. And if the upper surface of the first adhesive layer has a rigid layer, the thickness d of the first adhesive layer is in the following range: d1 ≤ d ≤ φ. If a number of rigid bodies are dispersed in the first adhesive layer, the first adhesive layer satisfies: E = PL0 / (πφ / 2 + φ).

[0049] where d1 = (L0 - φ) * (φ / 2 + h) / L0 + 2 * (2a + φ) * h / L0 - πφ / 2 * (90° - β) / (360° * L0), h = φ / 2 * cosβ, a = (φ / 2)^2 * sinβ, β ≤ 90°; or d1 = (L0 - φ) * (φ / 2 * cosβ) / L0, β > 90°;

[0050] In the above formula, φ is the diameter of the solder tape without including the solder layer; d1 is the minimum thickness of the first adhesive layer; L0 is the axial distance between two adjacent solder tapes; P is the lamination pressure; E is the Young's modulus of the first adhesive layer; β is the central angle between the intersection point of the bottom surface of the rigid layer and the solder tape and the vertex of the solder tape on the longitudinal section of the solder tape.

[0051] In this embodiment, the rigid layer 120 is relative to the first adhesive layer 110, and does not represent the absolute stiffness / hardness of the rigid layer 120. There is a difference in fluidity between the rigid layer 120 and the first adhesive layer 110.

[0052] The carrier film in this embodiment includes a first adhesive layer 110 and a rigid layer 120 (or discrete rigid bodies) functional layer. The first adhesive layer 110 functions to bond the battery cells. Since the first adhesive layer 110 needs to ensure excellent wetting and bonding with the battery cells, the first adhesive layer 110 needs to have good fluidity. On the other hand, if the fluidity of the first adhesive layer 110 is too high, the material of the first adhesive layer 110 is likely to flow under the solder tape, resulting in the failure of the contact between the welding and the battery cells. Of course, controlling the fluidity of the first adhesive layer 110 to maintain a good contact effect between the solder tape and the battery cells is a good way, but in practice, it is often difficult to control or set the fluidity of the first adhesive layer 110. Based on this, the thickness of the carrier film 10 in this embodiment is controlled, thereby indirectly controlling the influence of the first adhesive layer 110 on the solder tape, avoiding the failure of the contact between the solder tape and the battery cells, and ensuring that the first adhesive layer 110 can fill the gaps on both sides of the solder tape without penetrating under the solder tape, resulting in the failure of the contact between the welding and the battery cells.

[0053] Reference Figure 2 As shown, the structural schematic diagrams of the carrier film 10 after film covering, during lamination, and after lamination are shown from top to bottom in the figure. Figure 2One side of the carrier film 10 in contact with the solder strip 40 is the first adhesive layer 110, and the other side is the rigid layer 120. In addition, the outer surface of the solder strip 40 has a solder layer 401. The main body of the solder strip 40 is generally made of copper wire. After lamination, the carrier film 10 forms two areas, one is the adhesive layer filling area S1, and the other is the solder layer agglomeration area S2. The minimum thickness limit of the first adhesive layer 110 is as follows: assuming that the rigid layer 120 does not deform at all, after lamination, the rigid layer 120 forms a hard contact with the top of the solder strip 40, and the first adhesive layer 110 will be extruded and filled into the area S1 formed by the solder strip 40 and the rigid layer 120, and the solder layer 401 is filled into the area S2.

[0054] Specifically, if the upper surface of the first adhesive layer 110 has the rigid layer 120, referring to Figure 3 as shown, in the case of β ≤ 90°, the minimum thickness d1 of the first adhesive layer 110 can be calculated through geometric operations:

[0055] S1 = d1 * L0 = (L0 - φ) * (φ / 2 + h) + 2S0, where S0 is the Figure 3 area of the black region in

[0056] h = φ / 2 * cosβ;

[0057] a = (φ / 2)2 * sinβ;

[0058] β = 2ΔL / (πφ) * 90°;

[0059] β = 90° - α;

[0060] E = σ / ε = P / (ΔL / L0) = PL0 / ΔL;

[0061] ΔL = PL0 / E;

[0062] According to the area - angle relationship, it can be obtained that: S0 = (2a + φ) * h - πφ / 4 * (90° - β) / 360°;

[0063] Then d1 = (L0 - φ) * (φ / 2 + h) / L0 + 2 * (2a + φ) * h / L0 - πφ / 2 * (90° - β) / (360° * L0); It can be seen that the effect is optimal when β is 90°. β is the central angle between the intersection point of the bottom surface of the rigid layer 120 and the solder strip 40 and the vertex of the solder strip 40 on the longitudinal section of the solder strip 40.

[0064] In another case, if the upper surface of the first adhesive layer 110 has the rigid layer 120, referring to Figure 4 as shown, in the case of β > 90°, the minimum thickness d1 of the first adhesive layer 110 can be calculated through geometric operations:

[0065] S1 = d1 * L0 = (L0 - φ) * (φ / 2 - h);

[0066] h = φ / 2 * cosβ;

[0067] β = 2ΔL / (πφ) * 90°;

[0068] E = σ / ε = P / (ΔL / L0) = PL0 / ΔL;

[0069] ΔL = PL0 / E;

[0070] According to the angular relationship, it can be obtained that:

[0071] d1 * L0 = (L0 - φ) * (φ / 2 * cosβ);

[0072] Then d1 = (L0 - φ) * (φ / 2 * cosβ) / L0;

[0073] Among them, the effect is optimal when β is 90°. β is the central angle between the intersection point of the bottom surface of the rigid layer 120 and the solder strip 40 and the vertex of the solder strip 40 on the longitudinal section of the solder strip 40.

[0074] If there are several rigid bodies dispersed in the first adhesive layer 110, referring to Figure 5 as shown, then:

[0075] E = σ / ε = P / (ΔL / L0) = PL0 / ΔL;

[0076] ΔL = PL0 / E = πφ / 2 + φ;

[0077] Then it can be known that the first adhesive layer 110 needs to satisfy: E = PL0 / (πφ / 2 + φ).

[0078] In the above formulas, φ is the diameter of the solder strip (excluding the solder layer), d1 is the minimum thickness of the first adhesive layer, E is the elastic modulus of (the first adhesive layer 110), a physical quantity describing the ability of a material to resist deformation within the elastic deformation range, L0 is the axial distance between adjacent solder strips, P is the lamination pressure, ε is the strain of the rigid layer at the lamination temperature, ΔL is the amount of deformation at the lamination temperature, and σ is the stress, that is, the force per unit area.

[0079] It should be noted that when the first adhesive layer 110 is in contact with the solder strip 40, the solder layer on the solder strip 40 has flowed to the area S2 at this time. The contact between the first adhesive layer 110 and the solder strip 40 means that the first adhesive layer 110 is in contact with the inside of the solder strip 40 excluding the solder layer. For example, it is in contact with the copper wire inside the solder strip 40.

[0080] In this embodiment, the rigid layer 120 functions to press and cover the solder tape 40, preventing the deformation of the solder tape 40 caused by the stretching and placement of the solder tape by the press and cover welding machine, ensuring good contact between the solder tape 40 and the battery cell, and avoiding poor welding caused by deformation. Due to the pressing and covering function of the rigid layer 120, when the photovoltaic module is subjected to thermal shock, it can ensure the close contact between the solder tape 40 and the battery cell, and prevent the contact failure between the solder tape 40 and the battery cell caused by the thermal creep, stress release and retraction, solder re - aggregation and loss of the first adhesive layer 110 or the encapsulation film.

[0081] In one example, the melting point of the first adhesive layer 110 is 25°C to 120°C.

[0082] The melting point of the first adhesive layer 110 can affect its fluidity. In this embodiment, a suitable melting point is selected to make the fluidity of the first adhesive layer 110 meet the requirements. The melting point of the first adhesive layer 110 is 25°C - 120°C, which can form a pre - fixing force between the carrier film 10 and the battery cell. Therefore, the carrier film 10 can be laid and self - adhered at room temperature, or thermally adhered, press - covered and adhered at low temperature to form a pre - fixing with the battery cell.

[0083] In one example, the first adhesive layer 110 is made of one or more of the following materials: high - melt - index EVA (ethylene - vinyl acetate copolymer), acrylic acid, PVB (Polyvinyl Butyral), TPO (Thermoplastic Polyolefin), polyurethane, silicone, epoxy resin, and polyolefin.

[0084] In one example, the strain of the rigid layer 120 is greater than φ(π + 2) / 2L0.

[0085] In this embodiment, the rigid layer 120 functions to press and cover the solder tape 40, making the deformed solder tape 40 closely adhere to the surface of the battery cell. The tensile strength of the rigid layer 120 needs to be greater than the maximum pressure borne by the photovoltaic module during lamination. Generally, the lamination pressure of the photovoltaic module requires at least 0.05 Mpa, preferably ≥0.07 Mpa. Therefore, the strain of the rigid layer 120 during lamination needs to be greater than φ(π + 2) / 2L0.

[0086] In one example, the material of the rigid layer 120 is a polymer or a transparent inorganic substance, or the material of the rigid layer 120 is one or more of PET (Polyethylene Terephthalate), epoxy resin, polyurethane, hard plastic, thermoplastic, elastomer, and thermoplastic elastomer.

[0087] In one example, several rigid bodies are continuous structures or discontinuous structures, evenly dispersed in the first adhesive layer 110.

[0088] When several rigid bodies are discontinuous structures, the shapes of the several rigid bodies are in the form of powder, powder flakes and / or powdery filaments, and the materials of the several rigid bodies are one or more of the following: PET, epoxy resin, polyurethane, hard plastic, thermoplastic, elastomer, thermoplastic elastomer and glass.

[0089] Reference Figure 6 As shown, in the figure, there is a first adhesive layer 110, and the rigid bodies are discontinuous powder or powder flakes, which are basically evenly dispersed in the first adhesive layer 110. Under the pressure of these rigid bodies, the carrier film 10 can play the role of pressing the welding tape 40, and also makes the deformed welding tape 40 closely adhere to the surface of the battery cell.

[0090] In one example, when several rigid bodies are continuous structures, the materials of the several rigid bodies are glass fiber, fiber and / or hard plastic filaments. More preferably, the several rigid bodies are arranged in an orderly manner along the same direction.

[0091] Reference Figure 7 And Figure 8 As shown, Figure 7 shows that several fibrous rigid bodies are disorderly dispersed in the first adhesive layer 110, Figure 8 shows that several fibrous rigid bodies are orderly dispersed in the first adhesive layer 110, and Figure 8 it can be seen from [the figure] that these fibrous rigid bodies are orderly distributed, that is, in the same direction. No matter in what form these rigid bodies are dispersed in the first adhesive layer 110, the core is that the rigid bodies are basically evenly distributed, so that the carrier film 10 can play the role of pressing the welding tape 40.

[0092] In one example, the porosity of the rigid layer 120 ranges from 5% to 90%. This porosity is calculated according to the required quantity at fixed points, and its advantage is that it can save costs and reduce the risk of delamination caused by excessive residual stress due to the excessive hardness of the rigid layer 120.

[0093] In one example, reference Figure 9 As shown, the carrier film 10 further includes a second adhesive layer 130, and the second adhesive layer 130 is located on the upper surface of the rigid layer 120. The melting point of the second adhesive layer 130 is between 100°C and 150°C. In this embodiment, the second adhesive layer 130 bonds the rigid layer 120 and the encapsulation adhesive film layer, and plays a role of not sticking to the laminating machine and the mechanism during the laminating process.

[0094] In one example, reference Figure 10 As shown, the carrier film 10 further includes a barrier layer 140, and the barrier layer 140 is on the upper surface of the first adhesive layer 110 or on the upper surface of the rigid layer 120.

[0095] In this embodiment, when the carrier film 10 has the first adhesive layer 110 and the rigid layer 120, the barrier layer 140 is on the upper surface of the rigid layer 120; when the carrier film 10 has the first adhesive layer 110 and a rigid body, the barrier layer 140 is on the upper surface of the first adhesive layer 110.

[0096] Conventional carrier films use thermal lamination. After being heated, they are prone to shrinkage, resulting in the offset and deformation of the solder ribbons. Since lamination needs to be carried out at its melting point, there is a problem of sticking to the lamination equipment during the film laminating process, resulting in the inability to break through the production capacity and yield. In this embodiment, the barrier layer 140 plays a role in isolating the encapsulation adhesive film, preventing the highly fluid encapsulation adhesive film from penetrating under the solder ribbon 40.

[0097] The carrier film 10 of this embodiment includes a first adhesive layer 110. The upper surface of this layer has a rigid layer 120 or a number of rigid bodies are dispersed in the first adhesive layer 110. If the upper surface of the first adhesive layer 110 has a rigid layer 120, the thickness d of the first adhesive layer 110 is in the following range: d1 ≤ d ≤ φ; where d1 = (L0 - φ) * (φ / 2 + h) / L0 + 2 * (2a + φ) * h / L0 - πφ / 2 * (90° - β) / (360° * L0), h = φ / 2 * cosβ, a = (φ / 2)^2 * sinβ, β ≤ 90°, or d1 = (L0 - φ) * (φ / 2 * cosβ) / L0, β > 90°; if a number of rigid bodies are dispersed in the first adhesive layer 110, the first adhesive layer 110 satisfies: E = PL0 / (πφ / 2 + φ). This carrier film improves the contact performance between the solder ribbon and the solar cell, thereby improving the conduction efficiency.

[0098] Another embodiment of the present invention provides a photovoltaic module, as Figure 11 shown, including a front glass 20, a front adhesive film 30, a carrier film 10, a solder ribbon 40, a solar cell 50, a carrier film 10, a back adhesive film 60, and a back glass 70 connected in sequence. The photovoltaic module is laminated after being stacked, and the lamination temperature is 136°C to 170°C. At the same time, both the front and back of the photovoltaic module have a carrier film 10, and this carrier film 10 can adopt the carrier film in the foregoing embodiment, which will not be elaborated here.

[0099] In one example, the solar cell 50 is a main-gridless solar cell.

[0100] For the detailed structure of the carrier film 10 in this embodiment, reference can be made to the foregoing embodiment, which will not be elaborated here.

[0101] In the photovoltaic module of this embodiment, the carrier film 10 includes a first adhesive layer 110. The upper surface of this layer has a rigid layer 120 or a number of rigid bodies are dispersed in the first adhesive layer. If the upper surface of the first adhesive layer 110 has a rigid layer 120, the thickness d of the first adhesive layer 110 is in the following range: d1≤d≤φ; where d1 = (L0 - φ)*(φ / 2 + h) / L0 + 2*(2a + φ)*h / L0 - πφ / 2*(90° - β) / (360°*L0), h = φ / 2*cosβ, a = (φ / 2)²*sinβ, β≤90°, or d1 = (L0 - φ)*(φ / 2*cosβ) / L0, β>90°; If a number of rigid bodies are dispersed in the first adhesive layer 110, the first adhesive layer 110 satisfies: E = PL0 / (πφ / 2 + φ). This carrier film improves the contact performance between the solder tape and the cell, enhances the conduction efficiency, and thus improves the power generation efficiency of the photovoltaic module.

[0102] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0103] In some embodiments, numbers describing the composition and property quantities are used. It should be understood that such numbers used for the description of the embodiments are modified by the modifiers "about", "approximate" or "substantially" in some examples. Unless otherwise stated, "about", "approximate" or "substantially" indicate that the said numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, and such approximate values may change according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used to confirm the scope breadth in some embodiments of this application are approximate values, in specific embodiments, the setting of such numerical values is as precise as possible within the feasible range.

[0104] Although this application has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, as long as the changes and variations of the above embodiments are within the scope of the spirit of this application, they will fall within the scope of the claims of this application.

Claims

1. A carrier film, characterized in that: include: A first bonding layer, wherein the first bonding layer has a rigid layer on its upper surface or a plurality of rigid bodies are dispersed in the first bonding layer; If the first adhesive layer has a rigid layer on its upper surface, the thickness d of the first adhesive layer is in the following range: d1≤d≤φ; Among them, d1=(L0-φ)*(φ / 2+h) / L0+2*(2a+φ)*h / L0-πφ / 2*(90°-β) / (360°*L0), h =φ / 2*cosβ, a=(φ / 2)2*sinβ, β≤90°; or d1=(L0-φ)*(φ / 2*cosβ) / L0, β>90°; If a plurality of rigid bodies are dispersed in the first bonding layer, the first bonding layer satisfies: E=PL0 / (πφ / 2+φ); Wherein, φ is the diameter of the welding strip when the solder layer is not included; d1 is the minimum thickness of the first bonding layer; L0 is the axial distance between two adjacent welding strips; P is the lamination pressure; E is the Young's modulus of the first bonding layer; β is the central angle between the bottom surface of the rigid layer and the intersection of the welding strip and the vertex of the welding strip on the longitudinal section of the welding strip.

2. The carrier film according to claim 1, characterized in that: The melting point of the first adhesive layer is 25°C to 120°C.

3. The carrier film according to claim 1, characterized in that: The first bonding layer is made of one or more of the following materials: high melt index EVA, acrylic acid, PVB, TPO, polyurethane, silicone, epoxy resin and polyolefin.

4. The carrier film according to claim 1, characterized in that: The strain of the rigid layer is greater than φ(π+2) / 2L0.

5. The carrier film according to claim 1, characterized in that: The material of the rigid layer is a polymer or a transparent inorganic substance, or the material of the rigid layer is one or more of PET, epoxy resin, polyurethane, hard plastic, thermoplastic plastic, elastomer and thermoplastic elastomer.

6. The carrier film according to claim 1, characterized in that: The plurality of rigid bodies are continuous structures or discontinuous structures, and are uniformly dispersed in the first bonding layer.

7. The carrier film according to claim 6, characterized in that: When the plurality of rigid bodies are discontinuous structures, the plurality of rigid bodies are in the shape of powder, powder flakes and / or powdered filaments, and the materials of the plurality of rigid bodies are one or more of the following: PET, epoxy resin, polyurethane, hard plastic, thermoplastic plastic, elastomer, thermoplastic elastomer and glass.

8. The carrier film according to claim 6, characterized in that: When the plurality of rigid bodies are continuous structures, the material of the plurality of rigid bodies is glass fiber, fiber and / or hard plastic wire.

9. The carrier film according to claim 8, characterized in that: The plurality of rigid bodies are arranged in order along the same direction.

10. The carrier film according to claim 1, characterized in that: It also includes a second adhesive layer, which is located on the upper surface of the rigid layer and has a melting point between 100°C and 150°C.

11. The carrier film according to claim 1, characterized in that: A barrier layer is also included, and the barrier layer is on the upper surface of the first adhesive layer or on the upper surface of the rigid layer.

12. The carrier film according to claim 1, characterized in that: The porosity of the rigid layer ranges from 5% to 90%.

13. A photovoltaic module, characterized in that: It comprises a front glass, a front EVA, a front carrier film, a soldering tape, a battery cell, a back carrier film, a back adhesive film and a back glass connected in sequence, wherein the front carrier film and the back carrier film are the carrier films as described in any one of claims 1 to 12.

14. The photovoltaic module according to claim 13, characterized in that: The battery cell is a busbar-less battery cell.

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