Encapsulant film and method of manufacturing the same, solar cell module and method of manufacturing the same

Abstract

The embodiments of the present disclosure provide a packaging material film and a manufacturing method thereof, a solar cell module and a manufacturing method thereof. The packaging material film is configured for a solar cell, wherein the solar cell includes a plurality of solder strips, and the packaging material film includes: a first region, a projection of the first region on a plane where the solar cell is located at least partially overlaps with a projection of at least one of the plurality of solder strips, wherein a thickness of the first region is at least a part of a thickness of the packaging material film, and the packaging material film of the first region includes a packaging material with lower fluidity than other regions. The packaging material film can reduce the thickness of the packaging adhesive film on the back of the cell, and can also sufficiently protect the solder strips.

Description

Technical Field

[0001] The embodiments of the present invention relate to encapsulation material films and their manufacturing methods, and solar cell modules and their manufacturing methods. Background Technology

[0002] As the industry continues to develop, the manufacturing capacity of crystalline silicon is constantly improving, and various large-size silicon wafers are being used in the photovoltaic industry. Research on high-efficiency cells is also progressing steadily, and the market share of large-size multi-busbar solar cells is increasing. Large-size multi-busbar solar cells have advantages such as high efficiency and low cost. Currently, commonly used solder ribbons for solar cells include circular and flat ribbons. For solar cells, it is necessary to reduce the light obstruction by the metal solder ribbons to improve light extraction efficiency. Summary of the Invention

[0003] The embodiments of this disclosure provide an encapsulation material film and a method for manufacturing the same, as well as a solar cell module and a method for manufacturing the same, which can reduce the thickness of the encapsulation film on the back of the battery while providing sufficient protection for the solder ribbon.

[0004] In a first aspect, embodiments of this disclosure provide an encapsulation material film configured for use in a solar cell, wherein the solar cell includes a plurality of solder strips, and wherein the encapsulation material film includes: a first region, wherein the orthographic projection of the first region on the surface of the solar cell at least partially overlaps with the orthographic projection of at least one of the plurality of solder strips, wherein the thickness of the first region is at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region includes an encapsulation material with lower fluidity than that in other regions.

[0005] For example, the degree of cross-linking of the encapsulation material in the first region is higher than that in other regions.

[0006] For example, the melt flow index of the encapsulation material in the first region is lower than that of the encapsulation material in other regions.

[0007] For example, the encapsulation material includes one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and polyvinyl butyral (PVB).

[0008] For example, the encapsulation material includes ethylene-vinyl acetate copolymer, polyolefin elastomer, and co-extruded ethylene-vinyl acetate copolymer (EPE).

[0009] For example, the polyolefin elastomer is one or more copolymers of ethylene and butene, pentene, hexene or octene.

[0010] For example, the encapsulation material film comprises the same polymer material or a mixture of the same polymer materials.

[0011] For example, the encapsulation material in the first region is a polymer material with the same composition but different content than the encapsulation material in other regions; or the encapsulation material film includes a polymer material mixture, and the first region and the other regions include at least one polymer material with the same composition but different content.

[0012] Secondly, embodiments of this disclosure provide a solar cell module, comprising: a cell string including a plurality of cells connected to each other; an encapsulation material film disposed on at least one side of the cell string; and a plurality of solder ribbons disposed on at least one side of the cell string between the cell string and the encapsulation material film, wherein the encapsulation material film includes a first region, the orthographic projection of the first region on the surface where the cell string is located at least partially overlaps with the orthographic projection of at least one of the plurality of solder ribbons, the thickness of the first region is at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region comprises an encapsulation material with lower fluidity than that in other regions.

[0013] For example, the degree of cross-linking of the encapsulation material in the first region is higher than that in other regions.

[0014] For example, the melt flow index of the encapsulation material in the first region is lower than that of the encapsulation material in other regions.

[0015] For example, the encapsulation material includes one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and polyvinyl butyral (PVB).

[0016] For example, the encapsulation material includes ethylene-vinyl acetate copolymer, polyolefin elastomer, and co-extruded ethylene-vinyl acetate copolymer (EPE).

[0017] For example, the polyolefin elastomer is one or more copolymers of ethylene and butene, pentene, hexene or octene.

[0018] For example, the encapsulation material film comprises the same polymer material or a mixture of polymer materials.

[0019] For example, the encapsulation material in the first region is a polymer material with the same composition but different content than the encapsulation material in other regions; or the encapsulation material film includes a polymer material mixture, and the first region and the other regions include at least one polymer material with the same composition but different content.

[0020] For example, the encapsulation material film and the multiple solder strips are disposed on the back side of the battery string, and the solar cell further includes a backsheet material disposed on the side of the encapsulation material film away from the solder strips.

[0021] For example, the backplate material can be an inorganic or organic material, such as glass or PTFE cloth.

[0022] For example, the encapsulation material film and the multiple solder strips are disposed on the back and front of the battery string, and the solar cell module further includes: a backsheet material disposed on the back of the encapsulation material film away from the solder strips; and a front sheet material disposed on the front of the encapsulation material film away from the solder pads, wherein the backsheet material and the front sheet material are glass.

[0023] For example, the orthographic projection of the first region onto the surface where the battery string is located overlaps with the gap between the plurality of battery cells.

[0024] Thirdly, embodiments of this disclosure also provide a method for manufacturing a solar cell module, wherein the solar cell module is as described in any of the second aspects, the manufacturing method comprising: providing the cell string; distributing a plurality of solder strips on at least one side of the cell string; distributing an encapsulating material film on the plurality of solder strips, wherein a first region of the encapsulating material film is aligned with at least one of the plurality of solder strips; distributing a backsheet material on the encapsulating material film; and laminating using a laminator to form a laminate, wherein the thickness of the first region is at least a portion of the thickness of the encapsulating material film, and the encapsulating material film in the first region comprises an encapsulating material with lower fluidity than that in other regions.

[0025] Fourthly, embodiments of this disclosure provide a method for manufacturing an encapsulation material film as described in any of the first aspects, comprising: forming an encapsulation material into a material film; and processing the material film to form the encapsulation material film.

[0026] For example, the processing of the material film includes: irradiating the material film using a template, such that in at least a portion of the material film in the thickness direction of the encapsulation material film in a region corresponding to at least one of the multiple solder ribbons of the solar cell, the degree of crosslinking of the material film is higher than that in other regions, the template including a light-transmitting region and a light-shielding region, the light-transmitting region corresponding to at least one of the multiple solder ribbons of the solar cell.

[0027] For example, the process of forming the encapsulation material into a material film includes: adding a first material to the hopper corresponding to a first co-extrusion die; adding a second material with a melt flow index lower than that of the first material to the hopper corresponding to a second co-extrusion die; co-extruding the first material and the second material through the first co-extrusion die and the second co-extrusion die, and forming the encapsulation material film after cooling, wherein the second co-extrusion die and the first co-extrusion die are arranged side by side along a first direction of the encapsulation material film, the first direction being perpendicular to the extension direction of the solder ribbon of the solar cell, the position of the second co-extrusion die corresponding to at least one of the plurality of solder ribbons of the solar cell, and the width of the second co-extrusion die corresponding to the width of the solder ribbon. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0029] Figure 1A This is a top view of an exemplary encapsulation material film according to an embodiment of this disclosure;

[0030] Figure 1B It is along Figure 1A A cross-sectional view of the encapsulation material film taken by line A-A' in the diagram;

[0031] Figure 2A This is a top view of another example of an encapsulation material film according to an embodiment of this disclosure;

[0032] Figure 2B It is along Figure 2A A cross-sectional view of the encapsulation material film taken by line B-B' in the diagram;

[0033] Figure 3A This is a cross-sectional view of the encapsulation material film used in solar cells before lamination.

[0034] Figure 3B This is a cross-sectional view of the laminated solar cell module;

[0035] Figure 4A This is another example of an encapsulation material film used in a solar cell, shown in a cross-sectional view before lamination.

[0036] Figure 4B This is a cross-sectional view of the laminated solar cell module;

[0037] Figure 5 This is an example flowchart of a method for manufacturing an encapsulation material film according to an embodiment of the present disclosure. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms as used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected,” “linked,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0040] In solar cells, the circular solder ribbon structure reduces shading and reflects incident light from various angles. Therefore, most mainstream multi-busbar modules on the market currently use circular solder ribbons. Flat solder ribbons are typically 0.125mm thick. For the same cross-sectional area, the diameter of a circular solder ribbon is approximately 0.35mm (initially 0.4mm), about three times that of a flat ribbon. To ensure high yield during lamination and reliability, the encapsulation film required for these modules is thicker than that of conventional modules, typically more than twice the thickness and 1.5 times the weight. Even with a thicker encapsulation film, the larger diameter of the circular solder ribbon and the lamination process mean it cannot be fully protected by the encapsulation material, resulting in a larger gap between the backsheet material and the solar cells.

[0041] The closer the backsheet material, such as a glass backsheet, is to the solar cells, the stronger its reflection of light transmitted through the cells. Increasing the distance between the solar cells and the backsheet material will reduce the power of the module.

[0042] Furthermore, with the increasing use of large-size batteries, the size of modules is also increasing. This leads to a greater amount of encapsulation material used and a higher weight for the modules, increasing their cost and making transportation and installation more difficult. How to ensure module reliability while reducing module weight is a problem that the entire industry is actively researching now that large-size batteries are widely used.

[0043] The following two solutions are currently used in the industry.

[0044] 1. Reduce the diameter of the circular solder strip;

[0045] Problems: a. Currently, the smallest diameter that can be achieved for circular solder strips is 0.2mm. However, due to the reduced diameter of the solder strip, if the cell is not modified, the power loss of the module will increase, resulting in a sacrifice of power. If optimization is to be performed, the cell needs to be modified, increasing the number of main busbars, increasing the amount of silver paste consumed by the cell, and increasing the amount of solder strip used; b. After the solder strip becomes thinner, the yield strength of the solder strip decreases, making it easier to break during the production process. The solder strip is also softer, making it more difficult to stretch. The solder strip will bend, resulting in poorer stringing accuracy, increased welding difficulty, and a higher defect rate.

[0046] 2. Using segmented solder strips, the front side of the module uses circular or triangular solder strips to ensure full utilization of light, while the back side uses flat solder strips. Problems include: a. Sacrificing approximately 3% power on the back side; b. Segmented solder strips are more difficult to prepare, with higher residual stress at the segment interfaces, making them relatively easy to break; additionally, the panel shape needs to be fixed, and the length of the segmented solder strips is difficult to change arbitrarily once fixed; c. The welding process requires equipment modification for solder strip identification, and solder strip twisting must be avoided, increasing process defects.

[0047] Therefore, it is necessary to reduce the distance between the backsheet material and the battery cell without reducing the diameter of the currently used circular solder strip, while ensuring sufficient solder strip yield strength and low battery power loss. This means reducing the thickness of the encapsulation film on the back of the battery, while ensuring that the encapsulation film can wrap the back of the solder strip away from the battery cell after lamination, i.e., the side facing the backsheet material, to provide sufficient protection for the solder strip.

[0048] Embodiments of this disclosure provide an encapsulation material film and a solar cell using the encapsulation material film. The encapsulation material film includes a first region, the orthographic projection of the first region on the surface of the solar cell at least partially overlapping the orthographic projection of at least one of the plurality of solder strips, the thickness of the first region being at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region comprising an encapsulation material with lower fluidity than that in other regions. In this way, when the encapsulation material film is used to manufacture solar cells, the area containing the less fluid encapsulation material faces the solder ribbon. Therefore, during subsequent lamination of the solar cell, due to its lower fluidity compared to other areas, the encapsulation material in this area will not completely flow out of the space between the solder ribbon and the backsheet material due to pressure and temperature. Furthermore, the combination of the low-fluidity material and the high-fluidity material achieves directional placement of the encapsulation material in the solder ribbon area. Even after lamination, the encapsulation material remains between the backsheet and the solder ribbon, wrapping the back of the solder ribbon away from the cell, i.e., the side facing the backsheet material. This ensures that the flexible encapsulation material fills the space between the solder ribbon and the backsheet material, especially the glass backsheet, providing ample protection for the solder ribbon, improving cell yield, and preventing defects such as solder ribbon breakage and cell damage. Furthermore, because an encapsulating film is also filled between the solder ribbons protruding from the cell surface and the backsheet material, there is encapsulating film everywhere between the backsheet material and the cell. This allows the backsheet material to be firmly attached to the cell, and the encapsulating material can connect the front panel material, cell string, and backsheet material of the module to form a whole. In this way, without reducing the diameter of the currently used circular solder ribbons while ensuring sufficient solder ribbon yield strength and low cell power loss, the distance between the backsheet material and the cell is reduced, which means the thickness of the encapsulating film on the back of the cell is reduced. It also ensures that after lamination, the encapsulating film can wrap the back side of the solder ribbon away from the cell, that is, the side facing the backsheet material, providing sufficient protection for the solder ribbon.

[0049] The following description, in conjunction with the accompanying drawings, provides an exemplary account of the encapsulation material film and its manufacturing method, as well as the solar cell and its manufacturing method, according to embodiments of the present disclosure.

[0050] Figure 1A A top view of the encapsulation material film 3 is shown. Figure 1B It shows along Figure 1A The image shows a cross-sectional view of the encapsulation material film 3 taken along line A-A'. This encapsulation material film is constructed for use in solar cells, as shown below. Figure 1A and Figure 1B As shown, the encapsulation material film 3 includes a first region 3a, the thickness D1 of the first region 3a is at least a portion of the thickness D2 of the encapsulation material film, and the encapsulation material film in the first region includes encapsulation material with lower fluidity than other regions 3b. Figure 3AThis illustrates the state of the encapsulation material film when used in a solar cell and before lamination. Figure 3A The encapsulation material film 3 of this disclosure embodiment will be further described. For example... Figure 3A As shown, the solar cell includes a cell string 19 and multiple solder strips 4 disposed on the cell string 19. The cell string 19 includes multiple cells. The orthographic projection of the first region 3a of the encapsulation material film on the surface of the solar cell, that is, on the surface of the cell string 19, at least partially overlaps with the orthographic projection of at least one of the multiple solder strips 4.

[0051] For example, the orthographic projection of the first region 3a on the surface where the battery string 19 is located at least partially overlaps with the orthographic projection of at least one of the plurality of solder strips. This can include the orthographic projection of the first region 3a on the surface where the battery string 19 is located partially overlapping with one, two, or all of the plurality of solder strips. The embodiments of this disclosure are not limited to this. The orthographic projection of the first region 3a on the surface where the battery string 19 is located at least partially overlapping with the orthographic projection of the solder strip can be that the orthographic projection of the first region partially overlaps with the orthographic projection of the solder strip, or completely overlaps. Complete overlap can mean that they completely coincide or that the orthographic projection of the solder strip falls within the orthographic projection range of the first region.

[0052] For example, Figure 1A , Figure 1B and Figure 3A The illustration shows a case where the first region, comprising a less fluid encapsulating material, occupies only a portion of the thickness of the encapsulating material film. However, the thickness of the first region could also be equal to the thickness of the encapsulating material film, meaning the entire thickness of the encapsulating material film is comprised of encapsulating material with lower fluidity than other regions 3b. The embodiments of this disclosure are not limited to this, and those skilled in the art can make selections as needed, such that the first region comprising the less fluid encapsulating material is a portion or the entire thickness of the film. For example, the thickness of the first region 3a could account for 30-100% of the thickness of the encapsulating material film, or for example, the thickness of the first region 3a could account for 50-70% of the thickness of the encapsulating material film, thereby achieving both a reduction in the thickness of the encapsulating material film and sufficient protection for the solder ribbon.

[0053] It should be noted that when the encapsulation material film has a uniform thickness, the first region occupying at least a portion of the thickness of the encapsulation material film means that the thickness of the first region is at least a portion of the total thickness. When the thickness of the encapsulation material film is not uniform, the thickness of the first region may be at least a portion of the film thickness of the region where the first region is located. The region where the first region is located may refer to the region where the orthographic projection on the surface where the battery module is located completely coincides with the orthographic projection of the first region.

[0054] It should be noted that when the thickness of the first region 3a is a part of the thickness of the encapsulation material film, the first region 3a is not located in the middle of the thickness direction of the encapsulation material, but extends from the side surface in contact with the solder ribbon along the thickness direction to the other surface.

[0055] For example, the fluidity can be reflected by the degree of cross-linking or melt index of the polymer material. A high degree of cross-linking of the polymer material results in lower fluidity of the encapsulation material. A low melt index of the material means that it is not easy to melt under pressure and heating during lamination, resulting in lower fluidity. This ensures that the encapsulation material film corresponding to the solder ribbon does not easily flow out of the gap between the backsheet material and the solder ribbon when the battery is laminated.

[0056] Furthermore, Figure 2A A top view of another example encapsulation material film 10 is shown. Figure 2B It shows along Figure 2A The cross-sectional view of the encapsulation material film 10 taken by line B-B' is shown below. Figure 2A and Figure 2B As shown, the orthographic projection of the first region 10a of the encapsulation material film 3 onto the surface of the solar cell can at least partially overlap with the orthographic projection of the gap between the solar cells onto the surface of the solar cell; for example, they may completely overlap, partially overlap, or the orthographic projection of the gap between the solar cells may be located within the orthographic projection range of the first region. Figure 2A and Figure 2B As seen, a first region 10a is also provided in the gaps between longitudinally arranged solar cells, that is, in the gaps between solar cells arranged parallel to the extension direction of the solder strip, and a first region 10a is also provided in the gaps between transversely arranged solar cells, that is, in the gaps between solar cells arranged perpendicular to the extension direction of the solder strip. Further, see... Figure 2B , Figure 2B The diagram shows a first region 10a corresponding to the gap between transverse battery cells, which is formed to have a thickness D2 of the entire encapsulation material film, and a first region 10a corresponding to the solder strip, which has a thickness D1 that is a part of the encapsulation material thickness D2. This is just an example. Those skilled in the art should understand that the first region corresponding to the gap between longitudinal battery cells can also be set to have the thickness of the entire encapsulation material film, which can better bond the back sheet and the front sheet and improve battery stability.

[0057] Alternatively, the first region corresponding to the gap between the solar cells can also be configured to have only a portion of the thickness of the encapsulation material film.

[0058] Furthermore, the first region of the encapsulation material film can also correspond to the peripheral region of the battery string.

[0059] In this way, since the gaps between the cells A and / or the area around the cell string correspond to the first area of ​​the encapsulation material film with lower fluidity, after lamination, the encapsulation material film in the gaps between the cells will not flow out completely, but will be at least partially or completely retained. This allows for better bonding of the cells, front panel material, and back panel material, further improving the performance of the solar cell.

[0060] Figure 2B In the middle, five welding strips are arranged corresponding to a vertical row of solar cells, and Figure 4A and Figure 4B In the example, each column of vertical battery cells has six solder strips. These are just examples to illustrate the technical solution of this disclosure and are not intended to limit this disclosure. In practice, those skilled in the art can make the selection as needed.

[0061] For example, in the encapsulation material film 3, the degree of crosslinking of the encapsulation material in the first region 3a can be higher than the degree of crosslinking of the encapsulation material in other regions 3b.

[0062] For example, in the encapsulation material film 3, the melt index of the encapsulation material in the first region 3a may be lower than the melt index of the encapsulation material in other regions 3b.

[0063] For example, in embodiments of this disclosure, the encapsulation material may include one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and polyvinyl butyral (PVB). For instance, the encapsulation material may be ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), or polyvinyl butyral (PVB), or may be a mixture of any two of the three, or a mixture of the three.

[0064] For example, the polyolefin elastomer can be one or more copolymers of ethylene and butene, ethylene and pentene, ethylene and hexene, or ethylene and octene. When the encapsulation material is ethylene-vinyl acetate copolymer (EVA), EVA materials with different vinyl acetate (VA) contents can be used. When the encapsulation material is a polyolefin elastomer, copolymers of ethylene with butene, pentene, hexene, or octene, or copolymers with different ethylene contents with butene, pentene, hexene, or octene, can be used. Mixtures of two of EVA, POE, and PVB with different relative contents, or mixtures of all three with different contents, can also be used. When the encapsulation material film includes encapsulation materials with the same composition but different contents, they can be considered different encapsulation materials. For example, when the encapsulation material is an ethylene-vinyl acetate copolymer, if the components are the same but the VA content is different, they can be considered different encapsulation materials. When the encapsulation material is a mixture of polymer materials, if the components are the same but the contents are different, for example, if the encapsulation material includes a mixture of EVA and POE, and the EVA content is different, they can be considered different encapsulation materials. These are just two examples. Those skilled in the art can infer other cases, so they will not be elaborated here.

[0065] Alternatively, the encapsulation material may include a co-extruded material (EPE) of ethylene-vinyl acetate copolymer, polyolefin elastomer, and ethylene-vinyl acetate copolymer. For example, the encapsulation film may consist of three layers, namely, two layers of EVA sandwiched with POE, formed by co-extrusion. The main purpose of adding POE in the middle is to reduce the PID phenomenon of the module. Those skilled in the art will understand that the thickness of each of the three layers can be varied depending on the type of battery and module. For example, the bulk density of the encapsulation film formed by the three-layer co-extruded material can be 480 g / m², where the bulk density of the POE in the middle can be 150 g / m². Currently, bulk density is commonly used to control the thickness.

[0066] For example, the encapsulation material film may include the same polymer material or a mixture of the same polymer materials. That is, the first region 3a and other regions include the same polymer material, that is, polymer materials with the same composition and the same content, or a mixture of the same polymer materials, that is, a mixture of polymer materials with the same composition and the same content of each component; or, the encapsulation material in the first region 3a and the encapsulation material in other regions are polymer materials with the same composition but different contents; or the encapsulation material film includes a mixture of polymer materials, and the mixture of the first region and the other regions may have the same composition but at least one component with different contents, or both composition and content may be different, which will not be listed here.

[0067] Alternatively, if the degree of crosslinking of the encapsulation material in the first region 3a is higher than that of the encapsulation material in other regions 3b, the encapsulation material film may include the same polymer material or the same mixture of polymer materials. For example, the encapsulation material film may be ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyvinyl butyral (PVB), a mixture of EVA and POE, a mixture of EVA and PVB, a mixture of POE and PVB, or a mixture of all three. However, the encapsulation material components or compositions are the same and the content is the same in all regions. For example, EVA with the same VA content, a mixture of EVA and POE with the same EVA and POE content, etc., will not be listed here.

[0068] For example, when the degree of crosslinking of the encapsulation material in the first region 3a is higher than the degree of crosslinking of the encapsulation material in other regions 3b, the degree of crosslinking of the encapsulation material in other regions 3b can be zero or other lower values, and the degree of crosslinking of the encapsulation material in the first region 3a can be 1%-50%, as long as the degree of crosslinking of the encapsulation material in the first region 3a is higher than the degree of crosslinking of the region 3b.

[0069] For example, when forming the encapsulation material film, irradiation can be used to change the degree of crosslinking. This can be achieved by irradiating only the first region 3a while other regions 3b are not irradiated; or by changing the irradiation intensity and irradiation time to achieve different degrees of crosslinking. The irradiation intensity or irradiation time of other regions 3b can be lower or the irradiation time can be shorter, while the irradiation time and irradiation intensity of the first region 3a can be higher. The thickness range of the first region 3a can also be achieved by controlling the irradiation intensity and irradiation time. When the irradiation intensity is higher and / or the irradiation time is longer, the encapsulation material film of all thicknesses in the first region 3a can be at a higher degree of crosslinking.

[0070] For example, irradiation can be performed using one or more of the following: ultraviolet light, beta rays, gamma rays, X-rays, alpha rays, or neutron rays.

[0071] For example, the thickness of the encapsulation material film can be 0.2 to 1 mm, and further, the thickness can be 0.3 to 0.7 mm.

[0072] For example, the melt flow index of the encapsulation material in the first region 3a can be 1.5-15, while the encapsulation material in other regions 3b can be a polymer material with a higher melt flow index than that in the first region 3a. For example, the first region 3a and other regions can use polymer materials with the same composition but different contents. When the first region 3a and other regions are EVA, the melt flow index can be adjusted by changing the degree of polymerization of ethylene and vinyl acetate. Furthermore, the VA content of the EVA in the first region 3a and other regions differs. When the thickness of the first region 3a is a portion of the encapsulation material film thickness, EVA with different VA contents can occupy only a portion of the encapsulation material film thickness; or the entire thickness can be EVA with different VA contents. Other cases will not be listed individually.

[0073] When the encapsulation material film is a three-layer EPE co-extruded material, the VA content of the EVA layer in the first region may be different from that of other EVA materials in the same layer, or the melt index of the EVA layer + POE layer in the first region may be lower than that of the EVA layer and POE layer in other regions, or the melt index of the EVA layer + POE layer + EVA layer in the first region may be lower than that of the EVA layer and POE layer in other regions.

[0074] The encapsulation material film of this disclosure is configured for use in solar cells. By setting the encapsulation material with lower fluidity in all or part of the thickness area corresponding to the solder ribbon, it is possible to reduce the distance between the backsheet and the cell without reducing the diameter of the currently used circular solder ribbon (thus avoiding the power loss caused by reduced solder ribbon diameter and the defects of easy breakage due to low yield strength), while fully protecting the solder ribbon and ensuring a good bond between the backsheet and the solder ribbon. Furthermore, the areas with lower fluidity can also correspond to the gaps between the cells, thereby further improving the bonding strength between the backsheet, front sheet, and cells, and improving the performance and stability of the cell.

[0075] On the other hand, embodiments of this disclosure also provide a solar cell module comprising any of the encapsulation material films described above, such as... Figure 3A and Figure 3B As shown, Figure 3A A cross-sectional view of the solar cell module before lamination is shown. Figure 3B The diagram shows a cross-sectional view of the laminated solar cell module, that is, the final solar cell module formed. Figure 3A and Figure 3BAs shown, the solar cell module 100 includes: a cell string 19, comprising a plurality of cells connected to each other; an encapsulation material film 3 disposed on at least one side of the cell string; and a plurality of solder ribbons 4 disposed on at least one side of the cell string 19 between the cell string 19 and the encapsulation material film 3, wherein the encapsulation material film includes a first region 3a, the orthographic projection of the first region on the surface of the cell string 19 at least partially overlaps with the orthographic projection of at least one of the plurality of solder ribbons, the thickness of the first region 3a is at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region 3a comprises an encapsulation material with lower fluidity than other regions.

[0076] For example, the orthographic projection of the first region 3a on the surface where the battery string 19 is located at least partially overlaps with the orthographic projection of at least one of the plurality of solder strips. This can include the orthographic projection of the first region 3a on the surface where the battery string 19 is located at least partially overlapping with one, two, or all of the plurality of solder strips. The embodiments of this disclosure do not limit this. The orthographic projection of the first region 3a on the surface where the battery string 19 is located at least partially overlapping with the orthographic projection of the solder strip can also include complete overlap, the orthographic projection of the solder strip falling within the orthographic projection range of the first region, or partial overlap. The embodiments of this disclosure do not limit this, and those skilled in the art can choose according to their needs. However, in any case, it is possible to reduce the thickness of the encapsulation material film while ensuring that the encapsulation film, after lamination, can wrap the back side of the solder strip away from the battery cell, that is, the side facing the backsheet material, thus providing sufficient protection for the solder strip.

[0077] When the orthographic projection of the solder ribbon falls entirely within the orthographic projection range of the first region, the solder ribbon can be completely wrapped by the encapsulation material film. The solder ribbon is well protected and avoids damage. There is no area where the solder ribbon directly contacts the backsheet material between the backsheet material and the solar cell. The encapsulation material film is completely placed between the two, and the two are well bonded together, thereby further improving the performance of the solar cell.

[0078] For the sake of brevity, the materials of the encapsulation film will not be specifically described here. Please refer to the examples above for details. This section only describes solar cell modules that include encapsulation films and the situation where the encapsulation film is installed in a solar cell module.

[0079] For example, in the solar cell of this embodiment, the encapsulation material film 3 and the plurality of solder strips 4 may be disposed on the back side of the battery string 19, and the solar cell further includes: a backsheet material disposed on the side of the encapsulation material film away from the solder strips.

[0080] For example, the backplate material can be glass or PTFE cloth.

[0081] Figure 3A and Figure 3B In the solar cell shown, the encapsulation film 3 is disposed on the back side of the cell string, and the backsheet material is shown as PTFE cloth. Before lamination, as... Figure 3A As shown, the encapsulation material film 3 is disposed between the battery string 19, the solder ribbons 4, and the backsheet material 5. A first region 3a of the encapsulation material film is aligned with at least one solder ribbon 4, for example, with all solder ribbons 4. This alignment can be achieved by aligning the center of the solder ribbon 4 with the center of the first region 3a, or by having at least a portion of the orthographic projection of the solder ribbon 4 onto the surface of the battery string 19 overlap with the first region 3a. For example, the orthographic projection of the first region 3a can completely cover the orthographic projection of the solder ribbon, or the orthographic projections of the two can partially overlap.

[0082] It should be noted that when the first region 3a is not formed to the full thickness of the encapsulation material film, when the encapsulation material film 3 is placed on the battery string, the surface on the side where the first region 3a is located directly contacts the solder ribbon.

[0083] For example, the center of the solder ribbon 4 can be aligned with the center of the first region 3a. The projected area of ​​the first region 3a is greater than or equal to the projected area of ​​the solder ribbon, so that the back side of the solder ribbon after lamination can be completely protected by the encapsulation material film. This reduces the film thickness and the possibility of the solder ribbon being damaged, thereby improving battery performance.

[0084] During the lamination process of solar cell modules, the encapsulation material film melts under pressure and heat. However, in the first region 3a, due to the low fluidity of the encapsulation material, its fluidity is very low during lamination. Therefore, the encapsulation material between the solder ribbon and the backsheet material is partially or completely retained instead of flowing out. This, combined with the surrounding high-fluidity encapsulation material, allows the encapsulation film to be oriented symmetrically with the solder ribbon. After lamination, the space between the solder ribbon and the backsheet material is also filled with a flexible encapsulation material, protecting the cells from damage during module manufacturing and preventing solder ribbon breakage. Furthermore, because the backsheet material and the cell string are permeated with encapsulation film, the situation where all the encapsulation material between the solder ribbon and the backsheet material flows out, leaving the solder ribbon in direct contact with the backsheet material, ensures that the encapsulation material connects the cell string and the backsheet material, forming a cohesive whole and improving the performance of the solar cell module.

[0085] Figure 3B The image shows a solar cell with a backsheet made of PTFE cloth laminated together. Because PTFE cloth is relatively soft and thin, it forms... Figure 3B The form shown in the image.

[0086] Furthermore, the solar cell module 100 may also include an encapsulation material layer 2, solder ribbon 4, and front panel material 1 located on the front side of the cell string 19.

[0087] For example, the front panel material 1 can be glass.

[0088] For example, the encapsulation material layer 2 on the front side can be made of the same material as other areas 3b of the encapsulation material film 3, or it can be made of any material as used in the above embodiments, or it can be made of an encapsulation material film with a flowability of different from that of the encapsulation material in other areas, as on the back side. Those skilled in the art can make the selection as needed.

[0089] Figure 3B The diagram shows a single-glass module where the front panel is made of glass and the back panel is made of PTFE. The solar cell modules of this disclosure can also be double-glass modules where both the front and back panels are made of glass. Examples of double-glass modules with an encapsulation film on the back are not shown for simplicity.

[0090] Alternatively, in a solar cell module, the encapsulation material film and the plurality of solder strips are disposed on the back and front sides of the cell string, and the solar cell module further includes: a backsheet material disposed on the back side of the encapsulation material film away from the solder strips; and a front sheet material disposed on the front side of the encapsulation material film away from the solder strips, wherein the backsheet material and the front sheet material are glass.

[0091] For example, Figure 4A and Figure 4B The illustration shows the use of Figure 2A and Figure 2B A schematic cross-sectional view of a solar cell module with an encapsulation material film. Figure 4A The diagram shown is a schematic of the process before lamination. Figure 4B The image shown is a cross-sectional view after lamination. For example... Figure 4A As shown, the first region 10a corresponds to the solder strip setting, but for simplicity... Figure 4A The first region corresponding to the gap between the solar cells is not shown in the image; the laminated area... Figure 4B The diagram shows that the first region also corresponds to the gap between the solar cells. For example... Figure 4A and Figure 4BAs shown, in a solar cell module, the first region of the encapsulation material film can at least partially overlap with the orthographic projection of the gap between the solar cells onto the surface of the solar cell. For example, they may completely overlap, partially overlap, or the orthographic projection of the gap between the solar cells may lie within the orthographic projection range of the first region. Thus, since the gap between the solar cells corresponds to the first region of the encapsulation material film where the encapsulation material has lower fluidity, after lamination, the encapsulation material film in the gap between the solar cells will not completely flow out; it will be retained at least partially or entirely. This allows for better bonding of the solar cells, front panel material, back panel material, and the solar cells themselves, further improving the performance of the solar cell.

[0092] It should be noted here that the encapsulation material film will flow during the lamination process, combining... Figure 4A and Figure 4B as well as Figure 3A and Figure 3B If the first region corresponding to the solder ribbon is not the full film thickness before lamination, during the lamination process, the portion of the encapsulation material film overlapping the first region in the thickness direction will still flow, thinning the encapsulation film. Thus, after lamination, only the first region before lamination may remain in the area corresponding to the solder ribbon. Therefore, the first region corresponding to the solder ribbon after lamination may have the full film thickness. Of course, material from other regions may also remain in that area, so the first region corresponding to the solder ribbon after lamination may also have only a partial film thickness. However, it should be noted that due to film flow during lamination, the film thickness may be uneven after lamination. The portion corresponding to the solder ribbon, that is, the film between the solder ribbon and the backsheet material, may be thinner than the portion without the solder ribbon, i.e., the film between the cell surface and the backsheet material, because the solder ribbon protrudes beyond the cell surface. However, because a material with low flowability is used corresponding to the solder ribbon, the solder ribbon will still be protected by the encapsulation film and will not directly contact the backsheet material.

[0093] In practice, those skilled in the art may set the thickness of the first region as needed, so that the first region occupies all or part of the film thickness after lamination. The embodiments disclosed herein do not limit this.

[0094] For example, such as Figure 3B After lamination, the encapsulation material films on the front and back of the battery cell flow together where there are gaps, forming a layer like... Figure 3B The situation shown is different, but the material corresponding to solder strip 4 is still of low fluidity, for example, a material with high crosslinking degree or low melt index. Figure 3B In the solar cell module shown, a sealant 6 is provided on the outside of the front glass 1 and the back sheet material 5 to seal the outer edge of the cell string. A frame 7 is also provided to complete the fabrication of the solar cell.

[0095] Furthermore, for Figure 4A and Figure 4B The double-glass module shown herein, in order to protect the encapsulation material inside the module and ensure that the module can maintain the light transmittance and insulation of the encapsulation material after various aging processes, has a double-layer seal around its perimeter in the embodiments of this disclosure, such as... Figure 4B As shown, a sealing material 11 is provided between the backsheet and frontsheet materials of the double-glass module, and a sealant 6 is also provided on the outside of the backsheet and frontsheet materials, thus providing a double seal. In addition, a desiccant 13 is added between the two seals to further prevent moisture from seeping in from all sides of the module and damaging the solar cell module, thereby improving the stability and performance of the solar cell module.

[0096] For the solar cell module of this disclosure embodiment, without changing the diameter of the circular solder ribbon, the encapsulation material film corresponding to the solder ribbon includes an encapsulation material with low fluidity, such as high cross-linking degree and / or low melt index. This reduces the distance between the backsheet and the cell without increasing or even reducing the power loss of the cell and while maintaining the yield strength of the solder ribbon. It also ensures that the solder ribbon is wrapped by a flexible material to prevent damage to the solder ribbon and enhance the bonding strength between the backsheet and the cell.

[0097] Therefore, compared to reducing the solder ribbon diameter, the power output of the solar cell modules in this disclosure embodiment can be increased by 4 to 20 W for different cell sizes and designs. Compared to the flat back solder ribbon scheme, the back power output of the double-glass module can be increased by 1% to 2%. Table 1 below shows a performance comparison of solar cell modules with several diameters of circular and flat solder ribbons, where Pmax is the maximum front power, Isc is the short-circuit current, Voc is the open-circuit voltage, and FF is the fill factor. As can be seen from the table, the cross-sectional area of ​​the flat solder ribbon is higher than that of the 0.3 mm diameter circular solder ribbon, but the front power output is still 2% lower. The reason for the lower power output is that the solder ribbon shading causes a decrease in Isc, and the same result applies to the back power output. In Table 1, for the 0.35 mm diameter circular solder ribbon, its front power output is increased by 4% compared to the flat solder ribbon.

[0098] Table 1 Comparison of battery performance between circular and flat solder strips with several diameters.

[0099] 0.25mm 480.744 13.196 50.112 72.7 0.3mm 498.6 13.173 50.04 75.64 0.35mm 508.968 13.168 50.112 77.13 Flat welding strip 1.0*0.14mm 488.592 12.57 49.968 77.79

[0100] Furthermore, the solar cell module of this disclosure requires no changes to other materials and processes, ensuring that the module yield is not affected; the module weight is reduced by 100-200 g / m². 2Furthermore, the double-glass module is double-sealed on all four sides and protected by a desiccant, making it difficult for moisture to penetrate. This improves the module's resistance to PID (Potential Induced Degradation) and moisture resistance, reduces the requirements for the module's encapsulation materials and cells, and effectively isolates various external moisture and other corrosive gases, further enhancing the reliability of the solar cell module.

[0101] On the other hand, embodiments of this disclosure also provide a method for manufacturing an encapsulation material film as described above, such as... Figure 5 As shown, it includes:

[0102] The encapsulation material is made into a material film;

[0103] The material film is processed to form an encapsulation material film as described above, wherein the encapsulation material film is configured for use in a solar cell, wherein the solar cell includes multiple solder strips, and wherein the encapsulation material film includes: a first region, wherein the orthographic projection of the first region on the surface of the solar cell at least partially overlaps with the orthographic projection of at least one of the multiple solder strips, the thickness of the first region being at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region comprising an encapsulation material with lower fluidity than that in other regions.

[0104] For example, the first region of the encapsulation material film can be a region with a high degree of cross-linking or a region with a low melt index.

[0105] When the first region of the encapsulation material is a highly cross-linked region, the process of forming the encapsulation material into a film can be achieved by mixing the encapsulation materials to form a film. The encapsulation materials can refer to the materials described in the corresponding embodiments of the encapsulation material film above, and will not be repeated here for simplicity. For example, when the encapsulation material film includes a mixture of polymer materials, it can be a mixture of two or three of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), or polyvinyl butyral (PVB) to form a film. When the encapsulation material film includes a three-layer co-extruded material (EPE) of ethylene-vinyl acetate copolymer, polyolefin elastomer, and ethylene-vinyl acetate copolymer, the three materials can be extruded separately at different times using three rows of co-extrusion dies to form a film including the EPE co-extruded material.

[0106] For example, processing the material film may include: irradiating the material film using a template, such that in at least a portion of the material film in the thickness direction of the encapsulation material film, in a region corresponding to at least one of the multiple solder ribbons of the solar cell, the degree of crosslinking of the material film is higher than that in other regions, wherein the template includes a light-transmitting region and a light-shielding region, the light-transmitting region corresponding to at least one of the multiple solder ribbons of the solar cell.

[0107] For example, the degree of cross-linking of the encapsulation material film in the region corresponding to the light-shielding area of ​​the template is low or can be zero. Accordingly, when the region of the material film corresponding to at least one of the multiple solder ribbons of the solar cell is a high-cross-linking region while other regions are low-cross-linking regions, the entire material film can be irradiated with light first, and then the material film can be irradiated with a template whose light-transmitting area corresponds only to at least one solder ribbon, thereby forming the final encapsulation material film.

[0108] Alternatively, when the crosslinking degree in other regions is zero, the material film can be irradiated using a template whose transparent area corresponds only to at least one solder strip to obtain the final encapsulation material film. Those skilled in the art are not limited in this regard and can choose how to perform the irradiation as needed.

[0109] For example, when the encapsulation material film is formed of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), or polyvinyl butyral (PVB), the material can be irradiated with an irradiation source that can stimulate crosslinking of the material film. The degree and depth of crosslinking can be controlled by controlling the irradiation intensity and time.

[0110] When the encapsulation material film is formed from a mixture of polymer materials, it can be irradiated using an irradiation source capable of stimulating crosslinking of any of the components.

[0111] When the encapsulation material film is formed from three co-extruded EPE materials, the first region may be located only in the EVA layer, or in two layers of EVA and POE, or in three layers of EVA, POE, and EVA. The first region may be a portion of the thickness of one layer of EVA, the full thickness of EVA plus a portion of the thickness of POE, or the full thickness of EVA and POE plus a portion of the thickness of EVA. Those skilled in the art can select the thickness of the first region as needed.

[0112] When the first region of the encapsulation material film is an encapsulation material with a low melt index, the process of forming the encapsulation material film may include: adding a first material to the hopper corresponding to a first co-extrusion die; adding a second material with a melt index lower than that of the first material to the hopper corresponding to a second co-extrusion die; co-extruding the first material and the second material through the first and second co-extrusion dies, and forming the encapsulation material film after cooling. The second and first co-extrusion dies are arranged side-by-side along a first direction of the encapsulation material film, the first direction being perpendicular to the extension direction of the solder ribbons of the solar cell. The position of the second co-extrusion die corresponds to at least one of the plurality of solder ribbons of the solar cell, and the width of the second co-extrusion die corresponds to the width of the solder ribbon. For example, in... Figure 1AIn the diagram, the first direction can be the direction indicated by arrow C, and the direction indicated by arrow D is the extension direction of the solder strip.

[0113] For example, the first and second co-extrusion dies can be configured for each battery cell or arranged to correspond to multiple battery cells. The width of the second co-extrusion die can correspond to the solder strip, such that the material extruded from it corresponds to the first region corresponding to the solder strip. When each co-extrusion die is relatively narrow, multiple second co-extrusion dies can correspond to the region corresponding to one solder strip. Those skilled in the art can choose according to their needs. The first co-extrusion die extrudes the encapsulation material in other regions, and the second co-extrusion die extrudes the encapsulation material in the first region. After cooling, an encapsulation material film with a low melt index material in the first region is formed.

[0114] For example, when the encapsulation material film is formed from EVA, different regions of the encapsulation material film can have different melt indices by changing the VA content. For example, an encapsulation material with a melt index between 1.5 and 15 can be obtained by using EVA with a VA content of 28%-33%.

[0115] For example, when the encapsulation material film comprises a three-layer co-extrusion material (EPE) of ethylene-vinyl acetate copolymer, polyolefin elastomer, and ethylene-vinyl acetate copolymer, a three-row co-extrusion die can be used. The first region can be located only in the EVA layer, and only one row of co-extrusion dies corresponding to the solder strip can be filled with low melt index encapsulation material, while the other co-extrusion dies in the same layer are filled with the same material; or it can be located in two layers of EVA+POE, and the co-extrusion dies corresponding to the solder strip in two rows of co-extrusion dies can be filled with low melt index material, for example, the first layer is filled with EVA material with different VA content, and the second layer is filled with POE material with different melt index; or it can be located in three layers of EVA+POE+EVA, and the co-extrusion dies corresponding to the solder strip in three rows of co-extrusion dies can be filled with low melt index material, for example, the first and third layers are filled with EVA material with different VA content, and the second layer is filled with POE material with different melt index. The first region can be a portion of the thickness of an EVA layer, or it can be the total thickness of EVA plus a portion of the thickness of POE, or the total thickness of EVA and POE plus a portion of the thickness of EVA. For example, when the first region is a portion of the thickness of an EVA layer, the co-extrusion die of the corresponding layer can be filled with a mixture of low melt index and high melt index materials. Those skilled in the art can select according to their needs so that the thickness of the first region accounts for a different proportion of the thickness of the same EVA layer.

[0116] For example, processing the material film to form the encapsulation material film as described above may include: cooling the material film, for example, cooling the material film using casting rollers, shaping it after an embossing process, and then trimming and winding it up.

[0117] The material film can be cooled immediately after the encapsulating material is extruded from the co-extrusion unit using a co-extrusion die. For example, when forming a first region with a low melt index and a two- or three-layer co-extruded material film, one layer of material can be extruded first, followed by a second layer after a predetermined time, and then the next layer after another predetermined time. This predetermined time must be greater than zero and shorter than the material's cooling time; that is, the next layer is applied before the previous layer has completely cooled and solidified, thus ensuring both layering and sufficient bonding between the layers. Of course, those skilled in the art can employ other methods for this type of layered co-extruded material, and the embodiments disclosed herein do not limit this approach.

[0118] On the other hand, embodiments of this disclosure also provide a method for manufacturing a solar cell module as described above, the method comprising: providing the cell string; distributing a plurality of solder strips on at least one side of the cell string; distributing an encapsulation material film on the plurality of solder strips, wherein a first region of the encapsulation material film is aligned with at least one of the plurality of solder strips; distributing a backsheet material on the encapsulation material film; and laminating the encapsulation material film using a laminator to form a laminate, wherein the thickness of the first region is at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region comprises an encapsulation material with lower fluidity than that in other regions.

[0119] It should be noted that the encapsulation material film here is the encapsulation material film described in the above embodiments, obtained using the manufacturing method described above. For the sake of brevity, the parts that are the same as in the above embodiments will not be described again here; please refer to the above embodiments for details.

[0120] For example, the manufacturing method may also include: edge trimming inspection, applying sealant 6, installing frame 7 and junction box 8, etc., to produce solar modules.

[0121] For example, laminating using a laminator to produce laminated parts may include: evacuating the laminator for 8 minutes at a lamination temperature of 145°C and laminating for 10 minutes.

[0122] For example, lamination can be performed using a laminator in stages. The pressure of the first lamination can be 0 to 300 mbar, and the pressure of the second lamination can be 300 to 1000 mbar. By performing staged lamination, the pressure of each lamination can be appropriately reduced, thereby reducing the microcrack rate of the battery module.

[0123] For example, providing the battery string may include: using a string welding machine to manufacture battery strings with 12 half-cell batteries per string.

[0124] For example, an exemplary manufacturing method may include: fabricating a battery string with 12 half-cells per string using a stringer according to a design; laying the front panel material (glass) and front encapsulation material; connecting the battery strings in series or parallel using busbars or other conductors according to circuit requirements and setting the leads; laying the back encapsulation material, aligning the first area with the circular solder strips of the battery string; laying the back panel material, and inspecting and testing it; laminating it in a laminator to form a laminate; performing edge trimming inspection, applying sealant, and installing the frame and junction box, etc., to produce a solar cell module.

[0125] For example, another exemplary manufacturing method may include: fabricating a battery string according to a design; laying a front panel material (glass) and a front encapsulation material (EVA / POE / EVA co-extruded material); connecting the battery strings in series or parallel using busbars or other conductors according to circuit requirements, and setting up lead wires; laying a back encapsulation material (EVA / POE / EVA co-extruded material), aligning the first area with the circular solder strip area in the battery string; laying a first layer of sealing material around the perimeter, laying a back panel glass, and performing inspection and testing; laminating the battery in a laminator to form a laminate, wherein the lamination process may involve a lamination temperature of 145°C; edge trimming inspection; installing a desiccant around the laminated assembly; applying a sealant; installing the frame and junction box, etc., to form a solar cell module.

[0126] Alternatively, while aligning the first region of the encapsulation material film with at least one of the plurality of solder ribbons, the manufacturing method may include aligning the first region of the encapsulation material film with the gap between it and the battery cell and / or with the perimeter of the battery. This provides better protection for the battery assembly and stabilizes battery performance.

[0127] The encapsulation material film and its manufacturing method, and the solar cell module and its manufacturing method provided in this disclosure have the following beneficial effects:

[0128] 1. The solder ribbon corresponds to the first region where the fluidity of the encapsulation material film is low. This allows for a reduction in the distance between the backsheet material and the cell without reducing the diameter of the currently used circular solder ribbon, while ensuring sufficient solder ribbon yield strength and low battery power loss. It also ensures that the encapsulation film can wrap the back of the solder ribbon away from the cell after lamination, providing sufficient protection for the solder ribbon and enabling better bonding between the backsheet material and the cell.

[0129] 2. The first region with lower fluidity of the encapsulation material film can also correspond to the gap between the cells and / or around the cell, thereby enabling the front and rear panels to better bond with the cells and improve the stability of the cell.

[0130] 3. The battery module is sealed with a double layer, and a desiccant is added between the two layers to further prevent moisture from seeping in from all sides of the module and damaging the solar cell module, thereby improving the stability and performance of the solar cell module.

[0131] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of the invention is defined by the appended claims.

[0132] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of the invention is defined by the appended claims.

Claims

1. A method for manufacturing an encapsulation material film, wherein the encapsulation material film is configured for use in a solar cell, wherein the solar cell includes a plurality of solder ribbons, and wherein the encapsulation material film comprises: A first region, the orthographic projection of which onto the surface where the solar cell is located at least partially overlaps with the orthographic projection of at least one of the plurality of solder strips. The thickness of the first region is at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region comprises encapsulation material with lower fluidity than that in other regions. The degree of cross-linking of the encapsulation material in the first region is higher than that in the encapsulation materials in other regions. The encapsulation material in the first region is a polymer material with the same composition but different content than the encapsulation material in the other regions; or the encapsulation material film comprises a polymer material mixture, and the first region and the other regions comprise at least one polymer material with the same composition but different content. The manufacturing method includes: The encapsulation material is made into a material film; The material film is processed to form the encapsulation material film. The process of forming the encapsulation material into a material film includes: Add the first material to the hopper corresponding to the first co-extrusion die head; Add the second material, whose melt flow index is lower than that of the first material, into the hopper corresponding to the second co-extrusion die. The first material and the second material are extruded through a first co-extrusion die and a second co-extrusion die. After cooling, the encapsulation material film is formed. The second co-extrusion die and the first co-extrusion die are arranged side by side along a first direction of the encapsulation material film, the first direction being perpendicular to the extension direction of the solder ribbon of the solar cell. The position of the second co-extrusion die corresponds to at least one of the plurality of solder ribbons of the solar cell, and the width of the second co-extrusion die corresponds to the width of the solder ribbon. The encapsulation material film comprises at least two layers, wherein the first material and the second material are extruded through a first co-extrusion die and a second co-extrusion die, and the encapsulation material film is formed after cooling, comprising: First, extrude the first material; Cooling the first material layer for a predetermined time; After the predetermined time, the second material is extruded, wherein the predetermined time is greater than zero and less than the time it takes for the first material to completely solidify.

2. A method for manufacturing a solar cell module, wherein the solar cell module comprises: A battery string consists of multiple battery cells connected to each other. An encapsulation material film is disposed on at least one side of the battery string; Multiple solder strips are disposed on at least one side of the battery string between the battery string and the encapsulation material film. The encapsulation material film includes a first region, the orthographic projection of which on the surface where the battery string is located at least partially overlaps with the orthographic projection of at least one of the plurality of solder strips. The thickness of the first region is at least a portion of the thickness of the encapsulation material film. The encapsulation material film in the first region comprises an encapsulation material with lower fluidity than that in other regions. The melt flow index of the encapsulation material in the first region is lower than that of the encapsulation materials in other regions. The encapsulation material in the first region is a polymer material with the same composition but different content than the encapsulation material in the other regions; or the encapsulation material film comprises a polymer material mixture, and the first region and the other regions comprise at least one polymer material with the same composition but different content. The manufacturing method includes: Provide the battery string; Multiple solder strips are provided on at least one side of the battery string; An encapsulation material film is disposed on the plurality of solder strips, wherein a first region of the encapsulation material film is aligned with at least one of the plurality of solder strips; The backplate material is disposed on the encapsulation material film; Laminates are produced by laminating using a laminator. The thickness of the first region is at least a portion of the thickness of the encapsulation material film, and the encapsulation material film in the first region comprises encapsulation material with lower fluidity than that in other regions. The encapsulation material film is manufactured using the method described in claim 1.

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