Composite packaging adhesive film and photovoltaic module

Abstract

The utility model provides a composite packaging adhesive film and a photovoltaic module, the composite packaging adhesive film comprises a base material adhesive film layer and a blocking layer, the blocking layer comprises edge adhesive film parts at least arranged in edge areas of two opposite sides of the base material adhesive film layer, the outer side edge of the edge adhesive film part is flush with the outer side edge of the base material adhesive film layer; the total area of the orthographic projection of the blocking layer on the plane where the base material adhesive film layer is located is 5%-45% of the area of the base material adhesive film layer. According to the utility model, through the combination of the low-cost base material adhesive film layer and the high-water-vapor-barrier barrier layer, the edge water vapor barrier performance is improved, and the packaging material cost is greatly reduced.

Description

Technical Field

[0001] This utility model belongs to the field of solar photovoltaic modules, and relates to a composite encapsulation film and a photovoltaic module. Background Technology

[0002] With the development of the solar photovoltaic industry, photovoltaic module products based on various battery technologies are emerging one after another. However, regardless of the type of battery technology, industrialization must rely on mature, reliable, and cost-effective module packaging solutions to ensure the long-term and reliable use of photovoltaic cells in harsh outdoor environments.

[0003] Crystalline silicon solar cells, currently the mainstream type of solar cell in industrial production, primarily use a structure of glass + photovoltaic film + glass laminated together, or a structure of glass + photovoltaic film + polymer backsheet laminated together. They possess high resistance to oxidation, moisture, and alkali corrosion, and are encapsulated with an outer frame and silicone sealant to ensure the overall structural strength and sealing effect of the photovoltaic module. For high-humidity and high-temperature environments, double-glass / glass + metal backsheet solutions are often used. Compared to polymer materials (water vapor transmission rate ≈ 2g / m²),... 2 (day), the water vapor transmittance of glass or metal is approximately 0 g / m. 2 This design effectively isolates most external moisture from the photovoltaic cells, protecting them from external contamination. Additionally, two layers of encapsulating film separate the glass from the photovoltaic cells, filling the gap and further isolating them from air and moisture.

[0004] However, during long-term use, double-glass modules are prone to moisture corrosion of the internal cells due to the poor moisture barrier properties of the encapsulating film. Commonly used encapsulating films primarily use EVA (ethylene-vinyl acetate copolymer) or POE (polyolefin elastomer) particles as the main material, manufactured through processes such as adding additives, mixing, and casting. Conventional EVA encapsulating films easily decompose to release acetic acid under humid and hot conditions, leading to moisture intrusion and acetic acid release at the edges of the double-glass module under prolonged humid and hot environments. The free acid generated during aging creates an acidic environment inside the photovoltaic module, severely corroding metal materials such as solder ribbons and cell silver grid lines, causing excessive degradation of the photovoltaic module and a decrease in power generation. POE, on the other hand, has low moisture permeability and does not produce acetic acid under humid and hot conditions. It is often chosen for encapsulation in high-humidity and hot environments. However, due to its high cost and issues such as slippage and bubbles during the manufacturing process, resulting in a high defect rate, its application in the photovoltaic industry is very limited.

[0005] Therefore, it is crucial to ensure the moisture barrier properties of the encapsulating film while reducing the proportion of high-cost encapsulation materials used. Utility Model Content

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a composite encapsulation film and photovoltaic module. By using a thermal composite design of a low-cost substrate film layer and a high-value barrier film, the invention solves the problem of poor moisture barrier properties of conventional encapsulation films in photovoltaic module encapsulation, thereby reducing the cost of encapsulation films.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a composite encapsulating film, the composite encapsulating film comprising a substrate encapsulating film layer and a barrier layer, the barrier layer comprising at least an edge encapsulating film portion disposed on opposite side edge regions of the substrate encapsulating film layer, the outer edge of the edge encapsulating film portion being flush with the outer edge of the substrate encapsulating film layer; the total area of ​​the barrier layer projected onto the plane of the substrate encapsulating film layer is 5% to 45% of the area of ​​the substrate encapsulating film layer.

[0009] This invention improves the water vapor barrier performance at the edge of the module by laminating a barrier layer with low water vapor permeability into the edge region of the low-cost substrate film layer, shortening the water vapor intrusion depth and protecting the internal battery layer. At the same time, it reduces the amount of high water vapor barrier materials used. The preparation process is simple and low-cost, reducing the packaging cost of photovoltaic modules and enabling mass production of packaging materials.

[0010] The total area of ​​the barrier layer projected onto the plane of the substrate adhesive film layer can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or 45% of the area of ​​the substrate adhesive film layer, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0011] As a preferred embodiment of this utility model, the single-sided width of the edge adhesive film portion is 10mm to 700mm, for example, it can be 10mm, 50mm, 100mm, 200mm, 300mm, 400mm, 500mm, 600mm or 700mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0012] As a preferred embodiment of the present invention, the barrier layer further includes a central adhesive film portion disposed in the middle region of the substrate adhesive film layer, the two ends of the central adhesive film portion being respectively connected to the edge adhesive film portions on both sides, and the single-side width of the central adhesive film portion being equal to the single-side width of the edge adhesive film portion.

[0013] As a preferred technical solution of the present utility model, at least one of the central adhesive film parts is provided with a plurality of lead through holes, and the lead through holes sequentially penetrate through the central adhesive film part and the base material adhesive film layer.

[0014] When the composite encapsulation adhesive film of the present utility model is located on the side close to the component backplane, the lead through holes correspond to the electrode lead-out openings of the component backplane, alleviating the problem that the water vapor entering through the openings erodes the internal battery layer.

[0015] As a preferred technical solution of the present utility model, the base material adhesive film layer is rectangular; the barrier layer is in a double-strip shape, a "mouth" shape, an "H" shape or a "day" shape.

[0016] As a preferred technical solution of the present utility model, the mass of the composite encapsulation adhesive film is recorded as 100%, and the mass ratio of the barrier layer is 0.08% - 50%. For example, it can be 0.08%, 1%, 5%, 10%, 20%, 25%, 30%, 35%, 40%, 45% or 50%, but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0017] As a preferred technical solution of the present utility model, the unit grammage of the base material adhesive film layer is 100 - 500 g / m 2 , for example, it can be 100 g / m 2 , 150 g / m 2 , 200 g / m 2 , 250 g / m 2 , 300 g / m 2 , 350 g / m 2 , 400 g / m 2 , 450 g / m 2 or 500 g / m 2 , but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0018] The unit grammage of the barrier layer is 50 - 500 g / m 2 , for example, it can be 50 g / m 2 , 100 g / m 2 , 150 g / m 2 , 200 g / m 2 , 250 g / m 2 , 300 g / m 2 , 350 g / m 2 , 400 g / m 2 , 450 g / m 2 or 500 g / m 2 , but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0019] As a preferred embodiment of this invention, the water vapor transmission rate of the barrier layer is less than that of the substrate film layer.

[0020] In this invention, the barrier layer and the substrate film layer are thermally bonded and fixed, which improves the water vapor barrier performance while minimizing the amount of high-barrier, high-value materials used.

[0021] As a preferred embodiment of the present invention, the barrier layer is attached to the surface of the substrate adhesive film layer, or the barrier layer is at least partially embedded in the substrate adhesive film layer.

[0022] Secondly, this utility model provides a photovoltaic module, which includes a front panel glass, a first encapsulation layer, a battery layer, a second encapsulation layer and a back panel glass stacked sequentially; the first encapsulation layer and / or the second encapsulation layer are the composite encapsulation film described in the first aspect, and the edge encapsulation film portion of the composite encapsulation film is located at least on opposite sides of the battery layer.

[0023] That is, this utility model provides the following three solutions: (1) only the first encapsulation layer uses a composite encapsulation film; (2) only the second encapsulation layer uses a composite encapsulation film; (3) both the first and second encapsulation layers use composite encapsulation films. In the above three solutions, the barrier layer of the composite encapsulation film is close to the battery layer, and the edge film portion is located at both sides of the battery layer, which improves the water vapor barrier performance of the photovoltaic module edge and protects the battery layer from water vapor erosion.

[0024] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0025] This invention provides a composite encapsulation film and photovoltaic module, which shortens the depth of water vapor intrusion, ensures high water resistance at the edges of the photovoltaic module, and reduces the amount of high-value encapsulation materials used, thereby lowering the encapsulation cost of the photovoltaic module. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the thermal bonding of the substrate adhesive film layer and the double-strip barrier layer in the composite encapsulation film provided by this utility model.

[0027] Figure 2 for Figure 1 A schematic diagram of the padding strip being added during the thermal bonding process.

[0028] Figure 3 This is a schematic diagram of the thermal bonding of the substrate adhesive film layer and the "H"-shaped barrier layer in the composite encapsulation film provided by this utility model.

[0029] Figure 4This is a schematic diagram of the barrier layer with lead wire through holes in the composite encapsulation film provided by this utility model.

[0030] Figure 5 This is a schematic diagram of the structure of the composite encapsulation film provided in Embodiment 1 of this utility model.

[0031] Figure 6 This is a schematic diagram of the structure of the composite encapsulation film provided in Embodiment 2 of this utility model.

[0032] Figure 7 This is a schematic diagram of the structure of the composite encapsulation film provided in Embodiment 3 of this utility model.

[0033] Figure 8 This is a schematic diagram of the structure of a photovoltaic module provided in Application Example 1 of this utility model, wherein the dashed arrow indicates the depth of water vapor intrusion.

[0034] Figure 9 This is a schematic diagram of the water vapor intrusion depth and corrosion of a photovoltaic module provided for application example 1 of this utility model, wherein the dashed arrow indicates the water vapor intrusion depth.

[0035] Figure 10 This is a schematic diagram of the structure of a photovoltaic module provided in Comparative Application Example 1 of this utility model, wherein the dashed arrows indicate the depth of water vapor intrusion.

[0036] Figure 11 This is a schematic diagram of the water vapor intrusion depth and corrosion of the photovoltaic module provided in Comparative Application Example 1 of this utility model, wherein the dashed arrow indicates the water vapor intrusion depth.

[0037] Among them, 1-substrate adhesive film layer; 2-edge adhesive film portion; 3-center adhesive film portion; 4-back panel glass; 5-battery layer; 6-front panel glass; 7-first encapsulation layer; 8-second encapsulation layer; 9-lead wire through hole; 10-heating composite roller; 11-pad strip. Detailed Implementation

[0038] It should be understood that in the description of this utility model, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for 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 utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0039] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] Traditional double-glass photovoltaic modules or aluminum backsheet photovoltaic modules are prone to aging under long-term humid and hot environments. Because the water vapor transmission rate of the encapsulation materials used on the front and back sides is essentially zero, water vapor mainly enters the photovoltaic module from the edges and gradually diffuses into the module's interior over time. This invention provides the following solution to address the aforementioned technical problems.

[0042] In one specific embodiment, this utility model provides a composite encapsulation film, comprising a substrate film layer and a barrier layer. The barrier layer includes edge film portions disposed at least on opposite edge regions of the substrate film layer, with the outer edges of the edge film portions flush with the outer edges of the substrate film layer. The total area of ​​the barrier layer projected onto the plane of the substrate film layer is 5% to 45% of the area of ​​the substrate film layer. The substrate film layer and the barrier layer are bonded together using a thermal bonding process well-known to those skilled in the art. The barrier layer has a low proportion and is located at least at the edges, which effectively blocks moisture intrusion from the edges of the photovoltaic module and reduces the amount of high-value barrier layer used, thereby lowering the cost of the encapsulation material.

[0043] In some embodiments, the width of one side of the edge adhesive film portion is 10mm to 700mm. Since the size of the edge adhesive film portion covering the end face of the substrate adhesive layer is positively correlated with the moisture barrier effect, those skilled in the art can flexibly adjust the size of the edge adhesive film portion according to the required barrier effect to shorten the moisture penetration depth. It should be noted that when the edge adhesive film portion extends along the length direction of the substrate adhesive layer, the width of one side of the edge adhesive film portion refers to the linear length of the edge adhesive film portion in the width direction of the substrate adhesive layer; when the edge adhesive film portion extends along the width direction of the substrate adhesive layer, the width of one side of the edge adhesive film portion refers to the linear length of the edge adhesive film portion in the length direction of the substrate adhesive layer.

[0044] In some embodiments, the barrier layer is attached to the surface of the substrate adhesive film layer. Specifically, an integrated composite encapsulation film can be obtained by directly thermally bonding the barrier layer to the surface of the substrate adhesive film layer during the unwinding process. The preparation process is simple and fast.

[0045] In some embodiments, the barrier layer is at least partially embedded in the substrate adhesive film layer. Specifically, the surface of the substrate adhesive film layer is flattened by roll forming a roll forming groove, and then the barrier layer is thermally bonded in the roll forming groove, and then rolled to form a composite encapsulation film. This strengthens the adhesion between the substrate adhesive film layer and the barrier layer and prevents the barrier layer from falling off during winding or unwinding.

[0046] In this invention, the substrate film layer and the barrier layer can be any encapsulation material commonly used by those skilled in the art, including but not limited to EVA resin, POE resin, butyl rubber, TPO (thermoplastic olefin) film, etc. When selecting the encapsulation material, it is necessary to meet the requirement that the water vapor transmission rate of the barrier layer is lower than that of the substrate film layer. Those skilled in the art can select different materials to meet different process requirements.

[0047] For example, the substrate film layer uses low-cost EVA resin, and the barrier layer uses POE resin. The water vapor transmission rate of EVA is ≤30g / m³. 2 • Daily, POE water vapor transmission rate ≤ 5 g / m 2·day. The water vapor barrier performance of EVA resin is poor, resulting in serious attenuation of the electrical performance of photovoltaic modules under humid and hot conditions. The cost of POE resin with high water vapor barrier performance is more than 30% higher than that of EVA, and the process yield is not high, and problems such as slippage and lamination bubbles are likely to occur. The composite encapsulation film of the present utility model combines the advantages of these two different resins, EVA resin and POE resin, not only improves the edge water vapor barrier performance, but also greatly reduces the usage proportion of high-value film materials compared with traditional EPE (Expanded Polyethylene) films (POE proportion > 40%).

[0048] In addition, when the base film layer uses EVA resin, the barrier layer can be butyl rubber or TPO film; when the base film layer uses POE resin, the barrier layer can be butyl rubber or TPO film.

[0049] Further, the mass of the composite encapsulation film is recorded as 100%, and the mass proportion of the barrier layer is 0.08% - 50%. Those skilled in the art can flexibly adjust the thickness of the barrier layer and the base film layer according to the required barrier effect, and then adjust the mass proportion of the barrier layer to meet the required process requirements. Specifically, the unit mass of the barrier layer is 50 - 500 g / m 2 , and the unit mass of the base film layer is 100 - 500 g / m 2 .

[0050] In some embodiments, the barrier layer further includes a central film portion disposed in the middle region of the base film layer. Both ends of the central film portion are respectively connected to the edge film portions on both sides, and the unilateral width of the central film portion is equal to the unilateral width of the edge film portion. In the present utility model, the edge film portion and the central film portion can be thermally laminated on the surface of the base film layer, or thermally laminated in the rolling grooves of the base film layer. When the edge film portion and the central film portion are disposed in the rolling grooves, according to the specific positions of the edge film portion and the central film portion, the edges and the middle of the surface of the base film layer need to be rolled and flattened to form rolling grooves first, and then the edge film portion or the central film portion is thermally laminated in the rolling grooves, and then rolled and formed to obtain the barrier layer.

[0051] Further, when the composite encapsulation film is used as the encapsulation material on the side of the backplane glass of the photovoltaic module, the central film portion is provided with a plurality of lead through holes, and the lead through holes sequentially penetrate through the central film portion and the base film layer for leading out the electrodes of the photovoltaic module to ensure the protection effect.

[0052] In some embodiments, the base film layer is rectangular, and the barrier layer is in a double-strip shape, a "mouth" shape, an "H" shape or a "day" shape.

[0053] like Figure 1 As shown, when the barrier layer is double-striped, that is, the barrier layer only includes the edge adhesive film portions 2 attached to the opposite edges of the substrate adhesive film layer 1. In its manufacturing process, the substrate adhesive film layer 1 and the edge adhesive film portions 2 of the required size are extruded separately through processes commonly used by those skilled in the art, such as blending-twin-screw extrusion-casting-curing; then, the substrate adhesive film layer 1 is unwound, and during the unwinding process, the edge adhesive film portions 2 are simultaneously thermally bonded to both sides of the surface of the substrate adhesive film layer 1 using a heated composite roller 10. This process is fast and can match different panel sizes and specifications of component products, making it suitable for large-scale mass production. Figure 2 As shown, during the thermal bonding process, a padding strip 11 needs to be applied between the edge adhesive film portions 2 on both sides to protect the short side.

[0054] When the barrier layer is in the shape of a "U", that is, the barrier layer includes edge adhesive film portions 2 arranged circumferentially along the four edges of the substrate adhesive film layer 1 and connected end to end. The edge adhesive film portions on the left and right sides extend along the length direction of the edge of the substrate adhesive film layer, and the edge adhesive film portions on the front and rear sides extend along the width direction of the edge of the substrate adhesive film layer, which improves the water vapor barrier performance of the four edges of the component and more effectively protects the internal battery layer from water vapor erosion. In its manufacturing process, the substrate adhesive film layer 1 and the edge adhesive film portions 2 of the required size are extruded by means of processes commonly used by those skilled in the art, such as blending-twin-screw extrusion-casting-curing; then the substrate adhesive film layer 1 is unwound, and during the unwinding process, the edge adhesive film portions 2 are simultaneously heat-bonded on both sides of the surface of the substrate adhesive film layer 1 using a heated composite roller 10, and then the heated composite roller 10 is adjusted to heat-bond the edge adhesive film portions 2 on the other two sides.

[0055] When the barrier layer is "H"-shaped, that is, the barrier layer includes edge adhesive film portions 2 attached to the opposite edges of the substrate adhesive film layer 1, and a central adhesive film portion 3 located between the two edge adhesive film portions 2. Figure 3 As shown, in its manufacturing process, the substrate film layer 1, the edge film portion 2, and a central film portion 3 of the required size are extruded through processes commonly used by those skilled in the art, such as blending-twin-screw extrusion-casting-curing. Then, the substrate film layer 1 is unwound, and during the unwinding process, the edge film portion 2 is simultaneously heat-bonded to both sides of the surface of the substrate film layer 1 using a heated composite roller 10. Finally, the heated composite roller 10 is adjusted to heat-bond the central film portion 3. Additionally, when the composite encapsulation film is used as an encapsulation material on one side of the backsheet glass 4 of a photovoltaic module, such as... Figure 4 As shown, the central adhesive film portion 3 has a plurality of lead wire through holes 9, which pass through the central adhesive film portion 3 and the substrate adhesive film layer 1 in sequence, and are used to lead out the electrodes of the photovoltaic module.

[0056] When the barrier layer is in the shape of a Chinese character '日', that is, the barrier layer includes edge film parts 2 adhered to the opposite two side edges of the base film layer 1, and three central film parts 3 arranged in sequence between the two edge film parts 2. In the manufacturing process, first, through processes commonly used by those skilled in the art such as blending - twin - screw extrusion - casting - curing, the base film layer 1, two edge film parts 2 and one central film part 3 with required sizes are extruded respectively; then the base film layer 1 is unrolled, and during the unrolling process, the edge film parts 2 are thermally laminated to both sides of the end face of the base film layer 1 simultaneously by using the heating lamination roller 10, and then the heating lamination roller 10 is adjusted for thermal lamination of the three central film parts 3. In addition, when the composite encapsulation film is used as the encapsulation material on one side of the back - plate glass 4 of the photovoltaic module, a plurality of lead - through holes 9 are formed in the central film part 3, and the lead - through holes 9 penetrate through the central film part 3 and the base film layer 1 in sequence, which are used to lead out the electrodes of the photovoltaic module.

[0057] In another specific embodiment, the present invention provides a photovoltaic module, which includes a front - plate glass 6, a first encapsulation layer 7, a battery layer 5, a second encapsulation layer 8 and a back - plate glass 4 arranged in a stacked manner in sequence. The first encapsulation layer 7 and / or the second encapsulation layer 8 is the composite encapsulation film described in a specific embodiment, and the edge film parts 2 of the composite encapsulation film are at least located on the opposite two sides of the battery layer 5.

[0058] The present invention provides the following three solutions:

[0059] Solution 1: The first encapsulation layer 7 uses a composite encapsulation film, the base film layer 1 is arranged close to the front - plate glass 6, the edge film parts 2 are close to the battery layer 5 and are at least arranged on the opposite two side edges of the battery layer 5. The second encapsulation layer 8 uses a conventional encapsulation film, such as an EVA film or a POE film.

[0060] Solution 2: The first encapsulation layer 7 uses a conventional encapsulation film, such as an EVA film or a POE film. The second encapsulation layer 8 uses a composite encapsulation film, the base film layer 1 is arranged close to the back - plate glass 4, the edge film parts 2 are close to the battery layer 5 and are at least arranged on the opposite two side edges of the battery layer 5. Further, the second encapsulation layer 8 further includes a central film part 3 arranged in the middle of the surface of the base film layer 1, and a plurality of lead - through holes 9 are formed in the central film part 3 to enhance the protection effect.

[0061] Option 3: Both the first encapsulation layer 7 and the second encapsulation layer 8 employ composite encapsulation films. The substrate film layer 1 of the first encapsulation layer 7 is disposed near the front panel glass 6, and the edge film portion 2 is disposed near the battery layer 5, at least on opposite sides of the battery layer 5. Similarly, the substrate film layer 1 of the second encapsulation layer 8 is disposed near the back panel glass 4, and the edge film portion 2 is disposed near the battery layer 5, at least on opposite sides of the battery layer 5. Furthermore, the second encapsulation layer 8 also includes a central film portion 3 disposed in the middle of the surface of the substrate film layer 1, and the central film portion 3 has several lead wire through holes 9 to enhance the protective effect.

[0062] Example 1

[0063] This embodiment provides a composite encapsulation film, including a substrate encapsulation film layer 1 and a barrier layer. For example... Figure 5 As shown, the substrate adhesive film layer 1 is rectangular, and the barrier layer includes edge adhesive film portions 2 attached to the opposite two edges of the substrate adhesive film layer 1. The edge adhesive film portions 2 are rectangular and extend along the length of the substrate adhesive film layer 1, with their outer edges flush with the outer edges of the substrate adhesive film layer 1. The width of each side of the edge adhesive film portion 2 is 20 mm, such that the total area of ​​the barrier layer's orthographic projection onto the plane of the substrate adhesive film layer 1 is 20% of the area of ​​the substrate adhesive film layer 1. The substrate adhesive film layer 1 uses a material with a unit mass of 100 g / m³. 2 The EVA resin used in the edge film portion 2 has a unit mass of 80g / m 2 The POE resin. The mass of the composite encapsulating film is recorded as 100%, and the mass of the barrier layer is 5%.

[0064] Example 2

[0065] This embodiment provides a composite encapsulation film, including a substrate encapsulation film layer 1 and a barrier layer. For example... Figure 6 As shown, the substrate adhesive film layer 1 is rectangular. Two roller-pressed grooves are formed by rolling and compacting the two side edges of the surface of the substrate adhesive film layer 1. The barrier layer includes edge adhesive film portions 2 located in the two roller-pressed grooves. The edge adhesive film portions 2 are rectangular and extend along the length direction of the substrate adhesive film layer 1. The upper end face of the edge adhesive film portion 2 is flush with the upper end face of the substrate adhesive film layer 1, and the outer edge of the edge adhesive film portion 2 is also flush with the outer edge of the substrate adhesive film layer 1. The width of each side of the edge adhesive film portion 2 is 20 mm, so that the total area of ​​the barrier layer projected onto the plane of the substrate adhesive film layer 1 is 40% of the area of ​​the substrate adhesive film layer 1. The substrate adhesive film layer 1 uses a unit mass of 200 g / m³. 2 The EVA resin used in the edge film portion 2 has a unit mass of 100g / m 2 The POE resin. The mass of the composite encapsulating film is recorded as 100%, and the mass of the barrier layer is 10%.

[0066] Example 3

[0067] This example provides a composite encapsulation film, including a base film layer 1 and a barrier layer. As Figure 7 shown, the base film layer 1 is rectangular, and the barrier layer is in the shape of a Chinese character 'Ri', including edge film parts 2 pasted on the opposite side edges of the base film layer 1, and three central film parts 3 arranged in sequence between the two side edge film parts 2. The edge film parts 2 are rectangular and extend along the length direction of the base film layer 1, and the outer edges of the edge film parts 2 are flush with the outer edges of the base film layer 1. The single-side width of both the edge film parts 2 and the central film parts 3 is 10 mm, so that the total area of the positive projection of the barrier layer on the plane where the base film layer 1 is located is 45% of the area of the base film layer 1. The base film layer 1 uses EVA resin with a unit mass of 200 g / m 2 , and the edge film parts 2 use POE resin with a unit mass of 100 g / m 2 . The central film parts 3 have the same material as the edge film parts 2. The mass of the composite encapsulation film is recorded as 100%, and the mass ratio of the barrier layer is 25%.

[0068] Application Example 1

[0069] This application example provides a photovoltaic module. As Figure 8 shown, it includes a front panel glass 6, a first encapsulation layer 7, a battery layer 5, a second encapsulation layer 8, and a back panel glass 4 that are stacked in sequence. Among them, the first encapsulation layer 7 uses the composite encapsulation film of Example 1, and the second encapsulation layer 8 uses a conventional EVA film.

[0070] The water vapor intrusion depth and corrosion situation of the photovoltaic module provided in this application example are as Figure 9 shown.

[0071] Comparative Application Example 1

[0072] This comparative application example provides a photovoltaic module. As Figure 10 shown, the difference from Application Example 1 is that the first encapsulation layer 7 also uses a conventional EVA film, and the other structures are the same as those in Application Example 1.

[0073] The water vapor intrusion depth and corrosion situation of the photovoltaic module provided in this comparative application example are as Figure 11 shown.

[0074] From Figure 9 and Figure 11 , it is easy to see that the composite encapsulation film used in Application Example 1 effectively shortens the water vapor intrusion depth and alleviates the corrosion phenomenon by thermally compounding the edge film parts 2 with high water vapor barrier performance on the edges of the base film layer 1.

[0075] The applicant declares that the above description is only a specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model fall within the protection and disclosure scope of the present utility model.

Claims

1. A composite encapsulating film, characterized in that, The described composite encapsulation film includes a base film layer and a barrier layer. The barrier layer includes edge film portions disposed at least on the opposite side edge regions of the base film layer, and the outer edges of the edge film portions are flush with the outer edges of the base film layer; the total area of the orthographic projection of the barrier layer on the plane where the base film layer is located is 5% to 45% of the area of the base film layer.

2. The composite encapsulating film according to claim 1, characterized in that, The single-side width of the edge film portion is 10 mm to 700 mm.

3. The composite encapsulating film according to claim 1 or 2, characterized in that, The barrier layer further includes a central film portion disposed in the central region of the base film layer. The two ends of the central film portion are respectively connected to the edge film portions on both sides, and the single-side width of the central film portion is equal to the single-side width of the edge film portion.

4. The composite encapsulating film according to claim 3, characterized in that, At least one of the central film portions is provided with a plurality of lead through holes, and the lead through holes sequentially penetrate through the central film portion and the base film layer.

5. The composite encapsulating film according to claim 1, characterized in that, The base film layer is rectangular; the barrier layer is in a double-strip shape, a "mouth" shape, an "H" shape or a "day" shape.

6. The composite encapsulating film according to claim 1, characterized in that, Taking the mass of the described composite encapsulation film as 100%, the mass proportion of the barrier layer is 0.08% to 50%.

7. The composite encapsulating film according to claim 1 or 6, characterized in that, The substrate adhesive film layer has a unit weight of 100-500 g / m³. 2 The unit weight of the barrier layer is 50-500 g / m³. 2 .

8. The composite encapsulating film according to claim 1, characterized in that, The water vapor transmission rate of the barrier layer is less than that of the base film layer.

9. The composite encapsulating film according to claim 1, characterized in that, The barrier layer is adhered to the surface of the base film layer, or at least part of the barrier layer is embedded in the base film layer.

10. A photovoltaic module, characterized in that, The described photovoltaic module includes a front plate glass, a first encapsulation layer, a battery layer, a second encapsulation layer and a back plate glass which are sequentially stacked; the first encapsulation layer and / or the second encapsulation layer is the composite encapsulation film according to any one of claims 1-9, and the barrier layer of the composite encapsulation film is at least located on the opposite sides of the battery layer.

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