JPWO2019159729A1 - Solar cell module - Google Patents

Abstract

The solar cell module, which is an example of the embodiment, is formed between a plurality of solar cells, a first base material made of curved resin, a curved second base material, and between the first base material and the second base material. It includes a filled sealing layer and a buffer layer. The buffer layer is provided between the first base material and the plurality of solar cells, and has a lower shear modulus than the sealing layer. The cushioning layer is composed of a plurality of cushioning films arranged in the form of one sheet.

Description

The present disclosure relates to solar cell modules.

Conventionally, there is known a solar cell module provided on the light receiving surface side of a cell group composed of a plurality of solar cell cells and provided with a base material having a curved shape convex in the direction opposite to the cell group. Patent Document 1 discloses a solar cell module including a spherically curved base material. The curved solar cell module is installed in a part of the moving body exposed to sunlight, such as the roof of an automobile.

Further, in the conventional solar cell module, a glass base material is widely used as a base material arranged on the light receiving surface side of the cell group, but in order to reduce the weight of the module, a resin base is used instead of the glass base material. Modules using materials are also known (see Patent Document 2). Patent Document 2 discloses that a buffer layer made of a gel-like resin is provided in order to alleviate the thermal stress and local load of the resin substrate and suppress damage to the solar cell.

International Release 2016/031235 JP-A-2017-216425

By the way, a solar cell module provided with a resin base material and a buffer layer is manufactured by laminating (thermocompression bonding) a resin base material, a solar cell, a sealing layer, a buffer film constituting the buffer layer, and the like. At this time, if the resin base material is curved, it is difficult for the cushioning film to follow the curved surface of the resin base material, and many wrinkles may occur on the cushioning film. The buffer layer is in close contact with, for example, the sealing layer and the resin base material, but in the wrinkled portion, the sealing performance may be affected by a temperature change or the like.

An object of the present disclosure is to suppress wrinkles in a buffer layer in a solar cell module provided with a curved resin base material and a buffer layer.

The solar cell module according to one aspect of the present disclosure is provided on a plurality of solar cells and the first surface side of the plurality of solar cells, and has a curved shape that is convex in a direction opposite to the plurality of solar cells. A first base material made of resin, a second base material provided on the second surface side of the solar cell and having a curved shape convex in the direction of the first base material, and the first base material. A sealing layer filled between the second base material and a buffer layer provided between the first base material and the plurality of solar cells and having a shear elasticity lower than that of the sealing layer. The buffer layer is composed of a plurality of cushioning films arranged in the form of one sheet.

According to one aspect of the present disclosure, wrinkles in the buffer layer can be suppressed in a solar cell module provided with a curved resin base material and a buffer layer. According to the solar cell module according to the present disclosure, since the wrinkles of the buffer layer are suppressed, for example, the appearance of the module can be improved, and the influence of the wrinkles on the sealing performance can be suppressed.

It is a perspective view of the solar cell module which is an example of an embodiment. It is a figure which shows a part of the cross section of AA line in FIG. It is a figure for demonstrating the preferable length of a cushioning film. It is sectional drawing of the solar cell module which is another example of embodiment. It is sectional drawing of the solar cell module which is another example of embodiment. It is sectional drawing of the solar cell module which is another example of embodiment. It is a perspective view when the solar cell module which is another example of Embodiment is seen from the light receiving side (front side). It is a cross-sectional view which shows a part of the BB line cross-sectional view in FIG. 7, and is the cross-sectional view which shows the part of the YZ cross section which includes the Y direction and Z direction, and passes through a solar cell. It is a cross-sectional view which shows a part of the CC line sectional view in FIG. 7, and is the sectional view which shows the part of the YZ cross section which includes the Y direction and Z direction and does not pass through a string. It is a figure for demonstrating an example of the manufacturing method of a solar cell module. It is a figure for demonstrating the manufacturing method of the solar cell module of 1st reference example, and is the figure for demonstrating the problem of the manufacturing method of the solar cell module of 1st reference example. It is a figure for demonstrating another example of the manufacturing method of a solar cell module. It is a figure for demonstrating the manufacturing method of the solar cell module of the 2nd reference example, and is the figure for demonstrating the problem of the manufacturing method of the solar cell module of the 2nd reference example. It is a figure explaining the application of the manufacturing method of the solar cell module shown in FIG. 12 to the manufacturing of the solar cell module which does not contain a film.

Hereinafter, an example of the embodiment of the solar cell module according to the present disclosure will be described in detail with reference to the drawings. Since the drawings referred to in the embodiments are schematically described, the dimensional ratios of the components drawn in the drawings should be determined in consideration of the following description. In this specification, the terms "sheet" and "film" are used properly for convenience of explanation, but both of them mean a film-like material having a thin thickness.

The solar cell module according to the present disclosure is preferably mounted on a moving body, for example, a vehicle such as an automobile, a bicycle (electrically assisted bicycle), a train, a ship, or the like. Examples of vehicles include motorcycles, automobiles, electric vehicles, and hybrid vehicles. When the solar cell module is installed in an automobile, an electric vehicle, or a hybrid vehicle, it is preferably installed on the roof, and may be installed on the sunroof.

FIG. 1 is a perspective view of the solar cell module 10 which is an example of the embodiment, and FIG. 2 is a diagram showing a part of the AA line cross section in FIG. As illustrated in FIGS. 1 and 2, the solar cell module 10 includes a plurality of solar cells 11, a first base material 12 provided on the first surface side of each solar cell 11, and each solar cell. A second base material 13 provided on the second surface side of the cell 11 is provided. The first base material 12 is a resin base material having a curved shape that is convex in the direction opposite to that of the solar cell 11. The second base material 13 is a base material having a curved shape that is convex in the direction of the first base material 12, that is, in the direction of the solar cell 11.

In the present embodiment, the first surface of each solar cell 11 is a light receiving surface on which sunlight is mainly incident, and the second surface is a back surface (a surface opposite to the light receiving surface). Of the light incident on the solar cell 11, more than 50% of the light, for example, 90% or more of the light is incident from the light receiving surface side. The terms of the light receiving surface and the back surface are also used for the solar cell module 10 and the photoelectric conversion unit described later.

Further, the solar cell module 10 is provided between the sealing layer 14 filled between the first base material 12 and the second base material 13 and between the first base material 12 and the plurality of solar cell cells 11. The buffer layer 20 is provided. The sealing layer 14 has a function of being in close contact with the solar cell 11 to restrain the movement of the cell and sealing the solar cell 11 so as not to be exposed to oxygen, water vapor, or the like. In the present embodiment, the sealing layer 14 is composed of sealing layers 14A and 14B. The buffer layer 20 is a layer having a lower shear modulus than the sealing layer 14. As will be described in detail later, the cushioning layer 20 is composed of a plurality of cushioning films 21 arranged in the form of one sheet.

The solar cell module 10 illustrated in FIG. 1 has a rectangular shape in a plan view curved so as to be convex toward the light receiving surface side, but the shape can be changed as appropriate, such as a circular shape in a plan view, a polygonal shape other than a quadrangle, and the like. It may be. From the light receiving surface side, the solar cell module 10 includes a first base material 12, a buffer layer 20, a sealing layer 14A, a plurality of solar cell cells 11 (sometimes referred to as “cell group” in the present specification), and sealing. It has a laminated structure in which the layer 14B and the second base material 13 are laminated in this order.

The solar cell 11 has a photoelectric conversion unit that generates carriers by receiving sunlight, and a collector electrode that collects carriers from the photoelectric conversion unit. The photoelectric conversion unit illustrated in FIG. 1 has a substantially square shape in a plan view. Examples of the photoelectric conversion unit include a semiconductor substrate such as crystalline silicon (Si), gallium arsenide (GaAs), and indium phosphide (InP), an amorphous semiconductor layer formed on the semiconductor substrate, and an amorphous semiconductor. An example having a transparent conductive layer formed on the layer. Specifically, an i-type amorphous silicon layer, a p-type amorphous silicon layer, and a transparent conductive layer are sequentially formed on one surface of an n-type single crystal silicon substrate, and an i-type amorphous silicon layer is formed on the other surface. An example is a structure in which a silicon layer, an n-type amorphous silicon layer, and a transparent conductive layer are formed in this order.

The collector electrode is composed of a light receiving surface electrode formed on the light receiving surface of the photoelectric conversion unit and a back surface electrode formed on the back surface of the photoelectric conversion unit. In this case, one of the light receiving surface electrode and the back surface electrode is the n-side electrode, and the other is the p-side electrode. The solar cell 11 may have the n-side and p-side electrodes only on the back surface side of the photoelectric conversion unit. Generally, since the back surface electrode is formed in a larger area than the light receiving surface electrode, it can be said that the back surface of the solar cell 11 is the surface on which the area of the collector electrode is larger or the surface on which the collector electrode is formed. In the present embodiment, the light receiving surface electrode and the back surface electrode are provided as the collecting electrode.

The collector electrode preferably includes a plurality of finger electrodes formed over a wide area on the photoelectric conversion unit. However, the back surface electrode may be an electrode that covers substantially the entire back surface of the photoelectric conversion unit. The plurality of finger electrodes are fine line-shaped electrodes formed substantially parallel to each other. The collector electrode may include a busbar electrode that is wider than the finger electrode and is substantially orthogonal to each finger electrode.

The plurality of solar cells 11 are arranged between the respective base materials so as to be along the curved surfaces of the curved first base material 12 and the second base material 13, and are sealed by the sealing layer 14. Adjacent solar cells 11 are connected in series by a wiring material 30, thereby forming a string 33 of the solar cells 11. The wiring material 30 is generally called an interconnector or a tab, and is electrically connected to the collector electrode. It is preferable that a plurality of (generally two or three) wiring materials 30 are attached to the light receiving surface and the back surface of the solar cell 11. When the bus bar electrode is provided as the collector electrode, the wiring material 30 is attached along the bus bar electrode.

The wiring material 30 is provided from one end of one of the adjacent solar cells 11 to the other end of the other solar cell 11. The wiring material 30 bends between adjacent solar cell 11s in the thickness direction of the module, and a resin adhesive or solder is used on the light receiving surface of one solar cell 11 and the back surface of the other solar cell 11. Each is joined.

The solar cell module 10 preferably has a plurality of strings 33 in which a plurality of solar cell cells 11 are arranged in a row. Wiring materials 31 and 32 are provided on both sides of each string 33 in the longitudinal direction so as not to overlap with the solar cell 11. The crossover wiring material 31 is a wiring material that connects the strings 33 to each other. The crossover wiring material 32 is a wiring material that connects the string 33 and the output wiring. A terminal box 34 containing a bypass diode or the like may be provided on the back surface side of the solar cell module 10. In this case, the output wiring material to which the crossover wiring material 32 is connected is drawn into the terminal box 34.

The solar cell module 10 may include a frame attached along the peripheral edges of the first base material 12 and the second base material 13. The frame protects the peripheral edge of each base material and may be used when attaching the solar cell module 10 to the moving body. As shown in FIG. 1, the solar cell module 10 may be a so-called frameless module having no frame.

Hereinafter, the first base material 12, the second base material 13, the sealing layer 14, and the buffer layer 20 will be described in detail, and in particular, the buffer layer 20 will be described in detail.

The first base material 12 is a base material that covers the light receiving surface of a cell group composed of a plurality of solar cell cells 11 and protects each solar cell 11. The first base material 12 has a curved surface and is curved so as to be convex in the direction opposite to the cell group. A translucent resin base material is used as the first base material 12. By using a resin base material for the first base material 12, the weight of the solar cell module 10 can be reduced. On the other hand, the first base material 12 generally has a larger thermal expansion than the glass base material and is easily deformed when subjected to an impact. Therefore, it is preferable to provide a buffer layer 20 between the first base material 12 and the cell group to relieve the load applied to the solar cell 11.

The resin base material applied to the first base material 12 is, for example, an acrylic resin such as polyethylene (PE), polypropylene (PP), cyclic polyolefin, polycarbonate (PC), polymethylmethacrylate (PMMA), or polytetrafluoroethylene (PTFE). ), Polypropylene (PS), and at least one selected from polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). An example of a suitable resin base material is a resin base material containing polycarbonate (PC) as a main component, for example, a PC base material having a PC content of 90% by weight or more, or 95% by weight to 100% by weight. .. Since PC is excellent in impact resistance and translucency, it is suitable as a constituent material of the first base material 12.

The thickness of the resin base material constituting the first base material 12 is not particularly limited, but 0.001 mm to 15 mm is preferable in consideration of impact resistance (protection of the solar cell 11), light weight, light transmission, and the like. More preferably, 0.5 mm to 10 mm. The resin substrate is also called a resin substrate or a resin film. Generally, a thick one is called a resin substrate and a thin one is called a resin film, but it is not necessary to clearly distinguish between the two in the solar cell module 10. The total light transmittance of the resin base material is preferably high, for example, 80% to 100%, or 85% to 95%. The total light transmittance is measured based on JIS K7361-1 (Plastic-Test method for total light transmittance of transparent material-Part 1: Single beam method).

The first base material 12 has a spherically curved shape, and is curved in the X direction and the Y direction. Here, the X direction and the Y direction mean arbitrary directions orthogonal to each other in a plan view (two-dimensional plane) of the first base material 12 (the same applies to the second base material 13). Further, the Z direction means a direction orthogonal to the X direction and the Y direction (XY plane). That is, the first base material 12 has a curved shape that is convex in the direction opposite to the cell group in the XZ cross section and the YZ cross section. The first base material 12 has a curved surface having a three-dimensional curvature, for example, a shape obtained by cutting out a part of a spherical surface.

The curvature of the first base material 12 is not particularly limited, and may be constant over the entire area of the first base material 12 or may be different in some regions. The first base material 12 may have a flat portion in a part thereof, but preferably has a shape in which the whole is gently curved. A curved portion that is convex toward the cell group may be present in a part of the first base material 12. In the solar cell module 10, since the first base material 12 and the second base material 13 are curved toward the light receiving surface side, the cell group sandwiched between them, the sealing layer 14, and the buffer layer 20 are also on the light receiving surface side. It is curved. The sealing layer 14 that melts or softens in the laminating step easily curves following the curved surface of the base material.

The second base material 13 is a base material that covers the back surface of the cell group and protects each solar cell 11. The second base material 13 has a curved surface and is curved so as to be convex in the direction of the cell group. As the second base material 13, a translucent base material may be used as in the first base material 12, and an opaque base material is used when light reception from the back surface side of the solar cell module 10 is not assumed. May be done. The total light transmittance of the second base material 13 is not particularly limited and may be 0%. A glass base material or a metal base material may be used as the second base material 13, but it is preferable to use a resin base material in order to reduce the weight of the solar cell module 10.

The resin base material applied to the second base material 13 is, for example, an acrylic resin such as cyclic polyolefin, polycarbonate (PC), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polystyrene (PS), polyethylene terephthalate ( It is composed of at least one selected from polyesters such as PET) and polyethylene terephthalate (PEN), phenol resins, and epoxy resins.

The second base material 13 may be made of fiber reinforced plastic (FRP). In particular, FRP is preferably used in applications where impact resistance and light weight are required. Suitable FRPs include glass fiber reinforced plastics (GFRP), carbon fiber reinforced plastics (CFRP), aramid fiber reinforced plastics (AFRP) and the like.

The thickness of the second base material 13 is not particularly limited, but is preferably 0.05 mm or more. When the second base material 13 is made of FRP, the second base material 13 has a thickness equal to or greater than the thickness of one fiber. Considering the protection of the solar cell 11, the light weight, and the like, 0.05 mm to 10 mm is preferable, and 0.05 mm to 5 mm is more preferable. The thickness of the second base material 13 is preferably equal to or greater than the thickness of the first base material 12.

Like the first base material 12, the second base material 13 has a spherically curved shape and is curved in the X direction and the Y direction. The second base material 13 has a curved shape that is convex in the same direction as the first base material 12 in the XZ cross section and the YZ cross section. The second base material 13 has a curved surface having a three-dimensional curvature, for example, a shape obtained by cutting out a part of a spherical surface. The curvature of the second base material 13 may be constant over the entire area or may be different in some regions, but it is preferable that the second base material 13 has the same curvature as the first base material 12. Further, the second base material 13 may have a flat portion in a part thereof, but preferably has a shape in which the whole is gently curved.

As described above, the sealing layer 14 is provided between the first base material 12 and the second base material 13 to form a resin layer (sealing layer) that seals each solar cell 11. The sealing layer 14 is composed of a sealing layer 14A provided between the first base material 12 and the cell group, and a sealing layer 14B provided between the second base material 13 and the cell group.

The layer structure of the sealing layer 14 is preferably formed by the laminating step described later using the resin films constituting the sealing layers 14A and 14B, respectively. The same resin film may be used for the sealing layers 14A and 14B, or different resin films may be used. Examples of the resin applied to the sealing layer 14 include polyolefins, ethylene-vinyl acetate copolymers, and epoxy resins. Moreover, the resin may have a crosslinked structure.

The total light transmittance of the sealing layer 14A is preferably high, for example, 80% or more. On the other hand, the total light transmittance of the sealing layer 14B is not particularly limited. When light reception from the back surface side of the solar cell module 10 is not assumed, the sealing layer 14B may contain a coloring material such as a white pigment or a black pigment, and the total light transmittance may be 0%. ..

As described above, the buffer layer 20 is a layer having a lower shear modulus than the sealing layer 14. The buffer layer 20 has a function of alleviating the load applied to the solar cell 11 due to thermal expansion of the first base material 12 and deformation of the first base material 12 due to collision of a falling object, and suppressing damage to the solar cell 11. Have. Further, by providing the buffer layer 20, the stress acting on the wiring material 30 can be reduced and the breakage of the wiring material 30 can be suppressed.

The shear modulus of the buffer layer 20 is preferably 0.1 MPa or less, more preferably 0.001 MPa to 0.1 MPa. When the shear modulus of the buffer layer 20 is within the range, the stress relaxation effect can be obtained while ensuring the mechanical strength, manufacturing characteristics, and the like required for the solar cell module 10. Shear modulus is measured using a rheometer.

The buffer layer 20 is provided between the first base material 12 and the cell group so as to cover the entire cell group. The size of the buffer layer 20 is, for example, the same as the size of the first base material 12 or slightly smaller than that of the first base material 12. The solar cell module 10 has a structure in which the first base material 12, the buffer layer 20, and the sealing layer 14 are laminated in this order from the light receiving surface side, but the arrangement of each layer is not limited to this. For example, a laminated structure may be formed in which the buffer layer 20 is sandwiched between the sealing layers 14.

The cushioning layer 20 is composed of a plurality of cushioning films 21 arranged in the form of one sheet. That is, the buffer layer 20 is divided into a plurality of parts. When the buffer layer is formed by using a buffer film having the same size as that of the first base material 12, it is difficult for the film to follow the curved surface of the first base material 12, and many wrinkles occur in the film. In the solar cell module 10, since the cushioning layer 20 is formed by using a plurality of cushioning films 21, the size per film is smaller than the size of the first base material 12, and the film is made of the first base material 12. It becomes easy to follow the curved surface. Therefore, the wrinkles of the buffer film 21 can be suppressed, and a beautiful buffer layer 20 that follows the curved surface of the first base material 12 is formed.

The cushioning film 21 is preferably made of a transparent and highly flexible resin. The buffer film 21 may be composed of a gel-like resin, a hydrogel containing water, or an organogel containing an organic solvent. The cushioning film 21 is constructed using at least one selected from, for example, acrylic gel, urethane gel, and silicone gel. Above all, it is preferable to use a silicone gel having excellent durability.

The thickness of the cushioning film 21 is not particularly limited, but is preferably 0.1 mm to 10 mm or less, and more preferably 0.2 mm to 1.0 mm or less in consideration of protection of the solar cell 11 and light transmission. The total light transmittance of the buffer film 21 is preferably high, for example, 80% to 100%, or 85% to 95%. The plurality of cushioning films 21 are generally made of the same material and have the same dimensions.

The cushioning film 21 is, for example, a strip-shaped or strip-shaped film, and has a substantially constant width. Although it depends on the size, curvature, etc. of the first base material 12, the cushioning layer 20 is preferably composed of 2 to 10 cushioning films 21, and is preferably composed of 3 to 5 cushioning films 21. Is more preferable. The cushioning film 21 is arranged so that, for example, its longitudinal direction is along the longitudinal direction of the string 33. Each cushioning film 21 has a size that covers one or more rows of strings 33. In the example shown in FIG. 1, each cushioning film 21 is formed in a size that covers two rows of strings 33.

In the present embodiment, there is a gap between the adjacent buffer films 21A and 21B, that is, at the boundary portion 22 of the two cushion films 21A and 21B, and the gap is filled with the sealing layer 14. The cushioning film 21 may be arranged adjacent to each other with the edges of the film abutting each other so that a gap is not formed at the boundary portion 22. When there is a gap at the boundary portion 22, the width of the gap is preferably 1 mm or less. The gap may be present at all the boundary portions 22 of each cushioning film 21, or may be present at a part thereof.

Further, the end portion of the cushioning film 21 is provided at a position where it overlaps the gap between the solar cell 11s and the thickness direction of the module. By providing the end portion of the cushioning film 21 at a position where it does not overlap with the solar cell 11, the end portion can be made inconspicuous and a good appearance can be obtained. Further, it becomes easy to hide the end portion by providing the concealing layer 23 described later. In particular, when a gap is formed at the boundary portion 22 of the two cushioning films 21, it is preferable to provide the boundary portion 22 at a position overlapping the gap between the solar cell 11s. For example, all the boundary portions 22 (gap between the two cushioning films 21A and 21B) are provided at positions corresponding to the gap.

FIG. 3 is a diagram for explaining a suitable length W _{2 in the} X direction of the buffer film 21. The cushioning film 21 has, for example, a substantially rectangular shape in a plan view, and is arranged in the X direction, which is one of the plane directions of the first base material 12. In this case, the suitable length W _{2 in the} X direction of the buffer film 21 is not more than the length W ₁ of the first base material 12. By adjusting the length W ₂ to the length W ₁ or less, it becomes easy to suppress wrinkles in the buffer layer 20.
Here, the length W ₁ is
Arbitrary points arranged in the Y direction of the first base material 12 orthogonal to the X direction are A1, A2,
A line connecting the shortest distance to A1, A2 along the surface of the first substrate 12 alpha, L ₁ the length of the line alpha,
B1, B2, points drawn by drawing a perpendicular line γ of the same length along the surface of the first base material 12 with respect to the line α from A1 and A2,
The line connecting the B1, B2 in the shortest distance along the surface of the first substrate 12 beta, the length of the line beta L _2,
Then, it is the length of the perpendicular line γ when the length L ₂ of the line β is 99.0% or more of the length L ₁ of the line α.

The solar cell module 10 having the above configuration can be manufactured by laminating a group of cells using a first base material 12, a second base material 13, a sealing layer 14, and a plurality of buffer films 21. In the laminating apparatus, the first base material 12, the plurality of buffer films 21 arranged in the form of one sheet, the sealing layer 14A, the cell group, the sealing layer 14B, and the second base material 13 are arranged in this order on the heater. Stacked. The sealing layers 14A and 14B are preferably supplied in the form of a film. This laminate is heated to a temperature at which the resin films constituting the sealing layers 14A and 14B soften or melt, for example, in a vacuum state. After that, heating is continued while pressing each component against the heater side under atmospheric pressure, and each member is thermocompression bonded (laminated). In this way, the solar cell module 10 is obtained.

The plurality of cushioning films 21 are arranged in the form of a single sheet with their ends abutting each other or with a small gap at the boundary portion 22. At this time, it is preferable to arrange the cushioning films 21 so that the boundary portion 22 overlaps the gap between the solar cell 11s to form the laminated body.

As described above, in the solar cell module 10, since the buffer layer 20 is formed by using the plurality of cushioning films 21, the dimension per film is smaller than the dimension of the first base material 12, and each buffering is performed. It becomes easy to make the film 21 follow the curved surface of the first base material 12. Therefore, the wrinkles of the buffer film 21 can be suppressed, and a beautiful buffer layer 20 that follows the curved surface of the first base material 12 is formed. The solar cell module 10 has, for example, a good appearance and excellent sealing performance.

Hereinafter, another example of the embodiment will be described with reference to FIGS. 4 to 6. In the following, the same components as those in the above-described embodiment will be referred to with the same reference numerals, and duplicate description will be omitted.

The form illustrated in FIG. 4 is common to the form illustrated in FIG. 2 in that a gap exists at the boundary portion 22 of the adjacent buffer films 21A and 21B, and the sealing layer 14A is filled in the gap. On the other hand, in the example shown in FIG. 4, the boundary portion 22 is provided at a position where the solar cell 11 and the module overlap in the thickness direction. In this case, in order to make the boundary portion 22 inconspicuous, it may be provided at a position overlapping with the wiring material 30. By arranging the cushioning film 21 so that the wiring material 30 is located on the back side of the boundary portion 22, the boundary portion 22 becomes inconspicuous.

The form illustrated in FIG. 5 is common to the form illustrated in FIG. 2 in that the boundary portion 22 of the buffer films 21A and 21B is provided at a position where it overlaps with the gap between the solar cells 11. On the other hand, in the example shown in FIG. 5, a concealing layer 23 that covers the end portion (boundary portion 22) of the buffer film 21 is provided between the first base material 12 and the buffer layer 20. The concealing layer 23 hides the boundary portion 22 so that it cannot be seen from the first base material 12 side, and improves the appearance of the module.

The concealing layer 23 is formed by an area covering the entire boundary portion 22. Further, it is preferable to provide the concealing layer 23 only in a range that does not overlap with the solar cell 11, that is, a range that overlaps with the gap between the solar cells 11. In this case, it is possible to prevent the light incident on the solar cell 11 from being blocked by the concealing layer 23. The concealing layer 23 is formed in a plane visual band shape along, for example, a gap between the solar cells 11.

The concealing layer 23 may be provided by arranging a film constituting the concealing layer 23 between the first base material 12 and the buffer layer 20, or may be formed on the surface of the buffer layer 20 by printing or the like. It is preferably formed on the back surface of the first base material 12. The constituent material of the concealing layer 23 may be printed on the back surface of the first base material 12, or a film constituting the concealing layer 23 may be attached. Alternatively, the concealing layer 23 may be formed on the back surface of the first base material 12 by vapor deposition, sputtering, or the like. The thickness of the concealing layer 23 is not particularly limited, but an example of a suitable thickness is about 0.5 to 20 μm.

The concealing layer 23 may have a structure in which the coloring material is dispersed in the resin film, or a structure in which the coloring material is bound by a resin binder. The color (hue, color tone), visible light absorption rate, etc. of the concealing layer 23 can be adjusted by appropriately changing the type, density, layer thickness, and the like of the coloring material. The resin constituting the concealing layer 23 is not particularly limited, and a conventionally known resin binder used for printing ink can be used. The color of the concealing layer 23 may be adjusted to the same color as that of the solar cell 11 or the second base material 13. When the concealing layer 23 is black or dark blue, a black pigment such as carbon black, aniline black, titanium black, or magnetite can be used as the coloring material. Further, the concealing layer 23 may contain a yellow pigment, a red pigment, a blue pigment and the like.

The form illustrated in FIG. 6 is different from the form illustrated in FIG. 5 in that a barrier layer 15 is provided between the buffer layer 20 and the sealing layer 14A. Further, in the embodiment illustrated in FIG. 6, the films are arranged adjacent to each other in a state where the ends of the plurality of cushioning films 21 overlap each other in the thickness direction of the module. Since the ends of the two cushioning films 21A and 21B overlap each other, there is no gap at the boundary portion 22. In the embodiment illustrated in FIG. 6, since the barrier layer 15 exists between the buffer layer 20 and the sealing layer 14A, the ends of the buffer films 21 are overlapped with each other so as not to form a gap at the boundary portion 22. It is preferable to do so.

The barrier layer 15 is a layer having a lower oxygen transmittance than the first base material 12, and has a function of suppressing the action of oxygen permeating through the first base material 12 on the solar cell 11. The oxygen permeability of the barrier layer 15 is, for example, ^{200cm 3 / m 2 · 24h ·} atm or less. Oxygen permeability is measured based on JIS K7126. Further, the barrier layer 15 preferably has a lower water vapor permeability than the first base material 12. The barrier layer 15 covers the entire cell group and is provided between the first base material 12 and the cell group.

The barrier layer 15 is composed of a plurality of barrier films 16 arranged in the form of one sheet. That is, the barrier layer 15 is divided into a plurality of layers like the buffer layer 20. In this case, wrinkles of the barrier film 16 can be suppressed, and a beautiful barrier layer 15 that follows the curved surface of the first base material 12 is formed. The barrier layer 15 may have a seam 18 in which the ends of the barrier film 16 are joined to each other. The seam 18 is formed by joining the overlapping ends of two adjacent barrier films 16A and 16B to each other using an adhesive that develops adhesive strength in the laminating step.

The barrier film 16 may be composed of only a transparent resin film having a low oxygen permeability, and the resin film and an inorganic substance such as silicon oxide (silica) and aluminum oxide (alumina) formed on one side of the resin film. It may be composed of a compound layer. Examples of suitable resin films include fluororesin films such as polyvinyl fluoride (PVF) and ethylene-tetrafluoroethylene copolymer (ETFE), and polyester films such as polyethylene terephthalate (PET). The barrier film 16 is, for example, a PET film in which a vapor-deposited layer such as silica is formed on one side.

In the embodiment illustrated in FIG. 6, the concealing layer 23 is provided on the back surface of the first base material 12 at a position where the seam 18 of the barrier layer 15 and the boundary portion 22 of the buffer layer 20 overlap each other in the thickness direction of the module. Therefore, the seam 18 and the boundary portion 22 are concealed, and a good module appearance can be obtained.

Hereinafter, other embodiments of the solar cell module according to the present disclosure will be described in more detail with reference to FIGS. 7 to 14.

In the following description and description of the drawings, the X direction is the arrangement direction of the plurality of strings 33 described below, and is the first curve direction which is the extending direction of the first curve convex to the light receiving side. Further, the Y direction is the extending direction of the string 33, which is the extending direction of the second curve that intersects the first curve and is convex toward the light receiving side. The Z direction is the thickness direction of the solar cell modules 50, 110, 210. The solar cell modules 50, 110, 210 have a curved shape. Therefore, the X direction, the Y direction, and the Z direction are determined for each point in the three-dimensional coordinates of the solar cell modules 50, 110, 210. For example, the X direction of each point on the surface of the solar cell 11 is a tangential direction parallel to the arrangement direction of the strings 33 at that point, and the Y direction is parallel to the extending direction of the strings 33 at that point. It becomes the tangential direction. Further, the Z direction is the normal direction at that point. At each point of the three-dimensional coordinates on the surface of the solar cell 11, the X, Y, and Z directions are orthogonal to each other. The X, Y, and Z directions of the surface of the first base material 12 and the X, Y, and Z directions of the back surface of the second base material 13 are also the X directions on the surface of the solar cell 11. It can be determined by the same method as the determination direction in the Y direction and the Z direction. Further, the X direction, the Y direction, and the Z direction at each point of the three-dimensional coordinates of the other solar cell modules 50, 110, 210 are viewed from, for example, the Z direction (Z direction of the surface of the first base material 12). At that time, it can be determined as the same X direction, Y direction, and Z direction as the location on the surface of the first base material 12 that overlaps the point.

Like the solar cell module 10, the solar cell module 50 illustrated in FIG. 7 has a curved shape that is convex toward the light receiving side, and is curved in the X direction and also in the Y direction. The solar cell module 50 has a substantially rectangular shape in a plan view. The solar cell module 50 includes a terminal box 34 on one side and the back side in the Y direction. Further, as shown in FIG. 8, the solar cell module 50 includes a plurality of solar cell cells 11, a first base material 12, a second base material 13, a wiring material 30, a sealing layer 14, a barrier film 6, and a low elastic resin. The layer 7 is provided. The same configurations as those in the above-described embodiment can be applied to the solar cell 11, the first base material 12, the second base material 13, the wiring material 30, and the sealing layer 14.

The barrier film 6 is arranged on the light receiving side of the sealing layer 14, and has a coefficient of linear expansion smaller than that of the first base material 12. The barrier film 6 may have any thickness. However, the barrier film 6 preferably has a thickness of 110 μm or less, more preferably 30 μm or less, further preferably 25 μm or less, and most preferably 20 μm or less. On the surface 61 on the light receiving side of the barrier film 6, for example, a substantially circular cylindrical or truncated cone-shaped projecting portion 63 is provided so that the surface density is substantially uniform, and unevenness is provided. Further, the back surface 62 on the back side of the barrier film 6 is also provided with, for example, a substantially circular cylindrical or truncated cone-shaped projecting portion 64 in a plan view so that the surface density is substantially uniform, and unevenness is provided. However, the protrusions provided on the front surface on the light receiving side of the film and the back surface on the back side of the film may have an elliptical shape or a polygonal shape in a plan view, and may have any other shape in a plan view. May be good. Further, when viewed from the thickness direction of the barrier film 6, the concave portion 67 of the front surface 61 of the barrier film 6 may overlap the protruding portion 64 which is a convex portion of the back surface 62 of the barrier film 6, and the back surface of the barrier film 6 may be overlapped with the protruding portion 64. The recess 68 of the 62 may overlap the protrusion 63, which is a convex portion of the surface 61 of the barrier film 6. The recesses 67 and 68 have, for example, a substantially circular bottomed cylindrical hole or a truncated cone-shaped hole shape in a plan view. However, the recesses provided on the front surface on the light receiving side of the film and the back surface on the back side of the film are not limited to the shape thereof, and may have an elliptical shape or a polygonal shape in a plan view, and other than that in a plan view. It may have any shape, and may have any shape other than a cylinder or a truncated cone. Further, small irregularities such as wavy may be present on the outer peripheral surface and the tip surface of the protrusion provided on the front surface on the light receiving side of the film and the back surface on the back side of the film, and even if there are no small irregularities such as wavy. Good. Similarly, small irregularities such as wavy may be present on the inner peripheral surface and the bottom surface of the recesses provided on the front surface on the light receiving side of the film and the back surface on the back side of the film, and there are no small irregularities such as wavy. You may. Further, the unevenness may be provided uniformly on the surface of the film on the light receiving side, or may be provided randomly. Further, the unevenness may be uniformly provided on the back surface of the back side of the film, or may be provided randomly. The barrier film 6 is formed, for example, by embossing a flat film base material having a constant thickness, and by partially pushing up and floating the back surface of the film base material. FIG. 9 is a cross-sectional view showing a part of the CC line cross-sectional view of FIG. 7, which includes a part of the YZ cross section including the Y direction and the Z direction and does not pass through both the solar cell 11 and the wiring material 30. It is a figure. As shown in FIG. 9, the barrier film 6 has irregularities in a portion that does not overlap with both the solar cell 11 and the wiring material 30 when viewed from the thickness direction of the barrier film 6. That is, the unevenness of the barrier film 6 is provided, for example, at a position corresponding to a gap between adjacent strings 33 (a portion overlapping the gap in the thickness direction of the module). The barrier film 6 preferably has irregularities in a portion between two adjacent strings 33 in the first curve direction.

As the material of the barrier film 6, for example, the same material as the material of the existing gas barrier film that suppresses the passage of oxygen and water vapor can be adopted. The barrier film 6 may be made of the same film as the barrier film 16. The film may include, for example, a base film and a barrier laminate formed on the base film, and is formed by alternately providing organic layers and inorganic barrier layers on the base film. You may. For example, an organic layer, an inorganic barrier layer, an organic layer, and an inorganic barrier layer may be provided on one side of the base film in this order so that their surfaces are adjacent to each other. In the film, the barrier laminate may be provided on only one side of the base film, or may be provided on both sides. Further, the barrier laminate may be configured by laminating the inorganic barrier layer and the organic layer in this order from the base film side, or may be configured by laminating the organic layer and the inorganic barrier layer in this order. The film may have components other than the barrier laminate and the base film (for example, a functional layer such as an easy-adhesion layer). The functional layer may be arranged on the barrier laminate, between the barrier laminate and the base film, or on the side of the substrate film on which the barrier laminate is not installed.

It is preferable to use a plastic film as the base film. The plastic film is not particularly limited in material, thickness and the like as long as it can hold a laminated body such as an organic layer and an inorganic barrier layer, and can be appropriately selected depending on the purpose of use and the like. Specific examples of the resin constituting the plastic film include polyester resin, methacrylic resin, methacrylic acid-maleic acid copolymer, polystyrene resin, transparent fluororesin, polyimide, fluorinated polyimide resin, polyamide resin, and polyamideimide resin. Polyetherimide resin, cellulose acylate resin, polyurethane resin, polyether ether ketone resin, polycarbonate resin, alicyclic polyolefin resin, polyarylate resin, polyether sulfone resin, polysulfone resin, cycloolefilne copolymer, fluorene ring-modified polycarbonate resin , Alicyclic-modified polycarbonate resin, fluorene ring-modified polyester resin, and thermoplastic resins such as acryloyl compounds.

The low elasticity resin layer 7 is arranged between the first base material 12 and the barrier film 6. The low elastic resin layer 7 preferably has a tensile elastic modulus lower than that of the first base material 12, and has a tensile elastic modulus lower than that of any of the first base material 12, the second base material 13, and the sealing layer 14. It is more preferable if there is. Further, it is most preferable that the low elastic resin layer 7 has a tensile elastic modulus lower than that of any of the first base material 12, the second base material 13, the sealing layer 14, and the barrier film 6. However, the low elastic resin layer 7 may have a tensile elastic modulus similar to that of the first base material 12, or may have a tensile elastic modulus larger than that of the first base material 12. The low elastic resin layer 7 is preferably made of a gel-like translucent resin material (hereinafter, simply referred to as gel), and the gel may or may not contain a solvent. Examples of the solvent-containing gel include hydrogel in which the dispersion medium is a water gel, and organogel in which the dispersion medium is an organic solvent gel. Examples of gels containing a solvent include high molecular weight gels having a number average molecular weight of 10,000 or more, oligomer gels having a number average molecular weight of 1,000 or more and less than 10,000, and low molecular weight gels having a number average molecular weight of less than 1000. The low elasticity resin layer 7 may be made of the same material as the buffer layer 20.

However, it is preferable to use a polymer gel containing a solvent or a gel not containing a solvent because the movement of the plurality of solar cells 11 can be suppressed and the damage to the wiring material 30 due to the movement can be suppressed. Further, among the solvent-containing polymer gel or the solvent-free gel, it is preferable to contain at least one selected from the group consisting of silicone gel, acrylic gel, and urethane gel. These gels have a small tensile elastic modulus and easily relieve the thermal stress and local load of the first base material 12 due to temperature changes. Therefore, damage to the wiring material 30 can be effectively suppressed. In addition, the silicone gel has flexibility that can absorb an external impact, and it is easy to improve the adhesion to the substrate material and the resin material constituting the frame, and it is also excellent in moisture resistance and water resistance. Therefore, it is most preferable that the low elasticity resin layer 7 is composed of a silicone gel.

The tensile elastic modulus of the low elastic resin layer 7 is not particularly limited, but is preferably 0.1 kPa or more and less than 5 MPa, and more preferably 1 kPa or more and 1 MPa or less. By setting the lower limit of the tensile elastic modulus of the low elastic resin layer 7 to such a value, it becomes easy to fix the solar cell 11, and damage to the wiring material 30 due to the movement of the solar cell 11 can be suppressed. Further, by setting the upper limit of the tensile elastic modulus of the low elastic resin layer 7 to such a value, the thermal stress and the local load of the first base material 12 due to the temperature change can be efficiently relaxed.

The first base material 12, the low elasticity resin layer 7, the barrier film 6, the sealing layer 14, the solar cell 11, the wiring material 30, and the second base material 13 have a temperature of, for example, about 100 to 160 ° C. under high vacuum. It is bonded and integrated by the vacuum laminating process performed in. FIG. 10 is a diagram illustrating a method of manufacturing the solar cell module 50. Hereinafter, the outline of the vacuum laminating process will be described with reference to FIG.

When vacuum laminating, first, the curved front base material 19 which is the base material of the first base material 12 and the base material of the second base material 13 substantially correspond to the curved shape of the product. A back side base material 25 having a curved shape is prepared. The rigidity of the front base material 19 is smaller than or substantially the same as the rigidity of the back base material 25. Further, each of the front side and the back side original base materials 19, 25 has a curved shape in which all of the front side is convex toward the light receiving side, and the radius of curvature of the back surface of the front side original base material 19 is the surface 26 of the back side original base material 25. It is preferable that it is larger than the radius of curvature of. However, each of the front side and back side original base materials 19, 25 may have a curved shape that is convex toward the light receiving side as a whole, a part may have a flat plate shape, and a part may have a concave shape toward the light receiving side. It may be. Further, the thickness of the front base material 19 is preferably thinner in the central portion than in the peripheral portion. Each of the front side base material 19 and the back side base material 25 is formed by, for example, injection molding.

Next, for example, the back side original base material 25, the back side sheet material 41 forming the back side portion of the sealing layer 14 with respect to the solar cell 11, the solar cell 11 and the wiring material 30 (not shown in FIG. 10), and sealing. The front side sheet material 42 that constitutes the front side portion of the solar cell 11 in the stop layer 14, the film base material 43 that is the base material of the barrier film 6, the low elasticity resin base material 45 that is the base material of the low elasticity resin layer 7, and A laminated structure in which the front base material 19 is laminated in this order is arranged between a pair of silicone rubbers (diaphragms) of a vacuum laminating apparatus. As shown in the lower view of FIG. 10, that is, an enlarged view of a part of the film base material 43, the front surface and the back surface of the film base material 43 each have irregularities formed by embossing or the like.

Subsequently, one or both silicone rubbers are inflated by compressed air while exhausting the air between the laminated structures to the outside by evacuation, and the front side base material 19 is transferred to the back side base base material 25 until it becomes immovable. Bring it closer and pressurize the laminated structure in its thickness direction. In this process, as shown by the arrow C in FIG. 10, the film base material 43 is deformed from a flat shape to a curved shape. Further, in addition to the evacuation and pressurization, the laminated structure is heated at a temperature of, for example, about 100 to 160 ° C. by the heater of the vacuum laminating apparatus.

By the pressurization at this high temperature, the back surface of the front side base material 19, which has lower rigidity than the back side base material 25, is curved into a shape corresponding to the surface 26 of the back side base material 25. Then, the front base material 19 and the low elasticity resin base material 45 are brought into contact with each other without gaps, and the low elasticity resin base material 45 and the film base material 43 are brought into contact with each other without gaps. Further, the front side sheet material 42 and the back side sheet material 41 are fused so as to seal the solar cell 11 and the wiring material 30 (not shown in FIG. 10), and the front side sheet material 42 and the film base material 43 are bonded together. Glue. Further, the back side sheet material 41 and the back side original base material 25 are adhered to each other. By these fusions and the like, the front side base material 19 and the back side base base material 25 are bonded together, and the laminated structure is integrated in a shape corresponding to the product. In this way, the first base material 12 is formed from the front side base material 19, and the second base material 13 is formed from the back side base base material 25. Finally, for example, a frame is attached to the peripheral portion of the laminated structure to prevent the gel-like low elasticity resin layer 7 from flowing to the outside, and to form the solar cell module 50.

The case where the barrier film 6 is formed with irregularities by preliminarily forming irregularities on the film base material 43, which is the original material of the barrier film 6, by embossing or the like has been described. However, unevenness may be formed on the film by forming unevenness on the film original material which is the original material of the film at the time of laminating. Further, the radius of curvature of the back surface of the front side base material 19 is larger than the radius of curvature of the surface 26 of the back side base material 25, and the rigidity of the front side base material 19 is smaller than or substantially the same as the rigidity of the back side base material 25. The case was explained. Then, the case where the back surface of the front side original base material 19 is deformed along the surface 26 of the back side original base material 25 has been described. However, the back surface of the front base material may be flat and the surface of the back base material may be curved. Then, the back surface of the front base material may be curved along the surface of the back side base material. Further, the rigidity of the front base material is substantially the same as or higher than that of the back base material, and the radius of curvature of the back surface of the front base material is smaller than the radius of curvature of the surface of the back side base material. May be good. Alternatively, the rigidity of the front base material is substantially the same as or higher than that of the back base material, and the back surface of the front base material is a curved surface, while the surface of the back side base material is flat. You may. Then, the front surface of the back side base material may be deformed along the back surface of the side base material.

Further, the case where the thickness of the front base material 19 is thinner in the central portion than in the peripheral portion has been described. However, the thickness of the front base material to be deformed may be substantially constant. Further, a case where a pair of silicone rubbers are inflated with compressed air to pressurize the laminated structure in the thickness direction in the vacuum laminating process has been described. However, the pair of rubber plates may be moved by a pressure using flood control or the like so that the distance between the pair of rubber plates is reduced to compress the laminated structure arranged between the pair of rubber plates. Further, a case where the solar cell module includes a frame has been described. However, for example, a portion to be a side portion of the solar cell module is provided on one of the front side base material and the back side base material, and after vacuum laminating, a low elasticity resin layer is formed on this side portion. It may be sealed to prevent the low elasticity resin layer from flowing to the outside. Alternatively, the thickness of the solar cell module may be reduced from the central portion to the peripheral portion, and the first base material and the second base material may be adhered at the edge portion of the solar cell module. By adopting these structures, the solar cell module may not have a frame.

Again, referring to FIG. 7, the plurality of solar cell cells 11 are arranged in a matrix in the solar cell module 50. Two or more solar cells 11 arranged on the same straight line along the Y direction are connected in series by the wiring material 30. The string 33 is formed by the two or more solar cell 11s and the wiring material 30 connecting the two or more solar cells 11 in series.

In the example shown in FIG. 7, in two strings 33 adjacent to each other in the X direction, the solar cells 11 at one end in the Y direction are connected in series by relay wiring, and all the solar cells 11 are connected in series. .. As a result, the solar cell 11A arranged on the most terminal box 34 side in the Y direction and on the rightmost side on the paper surface is arranged on the highest potential side, and is arranged on the most terminal box 34 side in the Y direction and on the leftmost side on the paper surface. The solar cell 11B to be installed is arranged on the lowest potential side. Unlike the present embodiment, the solar cells arranged on the most terminal box side in the Y direction and on the rightmost side on the paper surface are arranged on the lowest potential side, and are arranged on the most terminal box side in the Y direction and on the paper surface. The solar cell arranged on the left side may be arranged on the highest potential side.

The solar cell module 50 is provided with four output wirings 32A, 32B, 32C, 32D for electrically connecting to the terminals of the terminal box 34 on the terminal box 34 side in the Y direction. The outer peripheral surfaces of the output wirings 32A, 32B, 32C, and 32D are covered with an insulating member such as an insulating film. Two of the four output wires 32A, 32B, 32C, 32D, the two output wires 32B, 32C also have a function of connecting two adjacent strings 33 in series. The output wiring 32A is arranged on the rightmost side in the X direction and is electrically connected to the high potential side of the string 33 on the highest potential side. Further, the output wiring 32B is arranged in the second row from the right in the X direction, and is arranged in the solar cell 11 on the lowest potential side of the string 33 having the second highest potential and in the third row from the right in the X direction. It is installed and electrically connects to the solar cell 11 on the highest potential side of the third highest potential string 33. Further, the output wiring 32C is arranged in the fourth row from the right in the X direction, and is arranged in the solar cell 11 on the lowest potential side of the fourth highest potential string 33 and in the fifth row from the right in the X direction. It is electrically connected to the solar cell 11 on the highest potential side of the fifth highest potential string 33. Further, the output wiring 32D is arranged in the sixth row from the right in the X direction and is electrically connected to the lowest potential side of the string 33 having the lowest potential.

The second base material 13 has a plurality of through holes (not shown). Each output wiring 32A, 32B, 32C, 32D is electrically connected to a predetermined terminal of the terminal box 34 after passing through any of the through holes. Although not described in detail, a bypass diode for preventing backflow is provided between the terminals in the terminal box 34. If a light-shielding object such as fallen leaves covers a specific solar cell 11, the amount of power generated by the solar cell 11 may decrease and heat may be generated. The two strings 33 connected in series including the solar cell 11 whose power generation amount is reduced by providing the bypass diode are substantially short-circuited by the bypass diode. As a result, no current flows through the two strings 33, and damage to the solar cell 11 due to heat generation is suppressed. The electric power from the solar cell module 50 is taken out by two electric power supply wirings (not shown) electrically connected to the terminals of the terminal box 34. In the example shown in FIG. 7, the solar cell module 50 has strings 33 arranged in 6 rows, but the solar cell module may have strings arranged in a plurality of rows other than the 6 rows.

As described above, the solar cell module 50 is a solar cell module having a convex curved shape on the light receiving side where light is mainly incident. Further, the solar cell module 50 includes a plurality of strings 33 arranged at intervals in the first curve direction (X direction), which is the extending direction of the first curve convex on the light receiving side. Further, each string 33 intersects the first curve and is arranged at intervals in the second curve direction (Y direction), which is the extending direction of the second curve convex on the light receiving side. , And a plurality of wiring materials 30 for electrically connecting the plurality of solar cells 11. Further, the solar cell module 50 includes a first base material 12 which is provided on the light receiving side with respect to the string 33, has a convex curved shape on the light receiving side, and is made of a translucent resin material. Further, the solar cell module 50 is provided on the back side opposite to the light receiving side with respect to the string 33, and seals the second base material 13 having a convex curved shape on the light receiving side and the plurality of strings 33. The sealing layer 14 is arranged in. Further, the solar cell module 50 has a low elasticity resin layer (filler layer) 7 arranged between the barrier film 6 arranged on the light receiving side of the sealing layer 14 and the first base material 12 and the barrier film 6. To be equipped. The linear expansion coefficient of the barrier film 6 is smaller than that of the first base material 12. Further, as described with reference to FIG. 9, the barrier film 6 has irregularities on a portion that does not overlap with both the solar cell 11 and the wiring material 30 when viewed from the thickness direction of the barrier film 6. Here, two or more solar cell 11s arranged on the same straight line along the Y direction and a wiring material 30 connecting the two or more solar cells 11 in series form a string 33. Therefore, the barrier film 6 has irregularities in the portion between the two adjacent strings 33 in the X direction.

According to the above configuration, the barrier film 6 has irregularities, and the film base material 43, which is the base material of the barrier film 6, has irregularities. Therefore, the film base material 43 is less likely to wrinkle during the laminating process, and as a result, the barrier film 6 in the finished product is also less likely to wrinkle, and as a result, the solar cell module 50 looks good and is less likely to peel off. Can be manufactured. Next, this will be described by comparing with the solar cell module 310 of the reference example. FIG. 11 is a diagram corresponding to FIG. 10 in the solar cell module 310 of the first reference example, and is a diagram for explaining a problem when a flat film base material 343 having no unevenness is used. In FIG. 11, the same configuration as in FIG. 10 is designated by the same reference number as in FIG. 10, and the description thereof will be omitted.

With reference to FIG. 11, when a flat film base material 343 is used as the film base material, the film base material 343 has a shape that does not easily absorb irregularities. Therefore, when the film base material 343 is curved during the laminating process indicated by the arrow D, the film base material 343 shrinks due to the unevenness generated on the surface of the front side sheet material 42 due to the shrinkage of the front side sheet material 42. It becomes difficult to follow smoothly. Therefore, wrinkles (too much) 380 are likely to be formed on the film base material 343, and these wrinkles 380 deteriorate the appearance of the solar cell module. In addition, the wrinkles 380 can serve as a starting point for peeling, can also serve as an infiltration route for water, and can serve as a hotbed for deterioration. Depending on the specifications, a film having a thin thickness may be desired, and a film having a thickness of 25 μm or less or a film having a thickness of 20 μm or less may be desired. However, in such a case, since the rigidity of the film is small and the film is weakened, it becomes more difficult for the film to follow the shrinkage of the front sheet material, and the possibility of wrinkles increases.

On the other hand, in the case of the present embodiment shown in FIG. 10, since the barrier film 6 has unevenness and the film base material 43 which is the base material of the barrier film 6 has unevenness, the film base material 43 is caused by the unevenness. It has a springy property. Therefore, the unevenness of the front side sheet material 42 caused by the shrinkage of the front side sheet material 42 can be absorbed by its spring property, and the force applied from the front side sheet material 42 by the spring property of the film base material 43 is applied to the film base material 43. It becomes easy to disperse globally and uniformly. Therefore, the film base material 43 tends to shrink uniformly during the laminating process, and wrinkles are less likely to be formed on the film base material 43. As a result, the solar cell module 50 can be made to look good and to be less likely to be peeled off or deteriorated.

Further, the filler layer provided between the first base material 12 and the barrier film 6 may be a low elasticity resin layer 7 having a tensile elastic modulus lower than that of the first base material 12.

According to this configuration, the low elastic resin layer 7 having a low tensile elastic modulus is provided between the first base material 12 and the barrier film 6. Therefore, even if the first base material 12 is a resin base material having a high coefficient of linear expansion, the low elasticity resin layer 7 can mitigate the influence of heat shrinkage of the first base material 12. Therefore, the influence of the heat shrinkage of the first base material 12 is less likely to be transmitted to the wiring material 30, and damage to the wiring material 30 can be suppressed.

Further, the unevenness may be provided on both the front surface 61 on the light receiving side of the barrier film 6 and the back surface 62 on the back side of the barrier film 6. Further, when viewed from the thickness direction of the barrier film 6, the concave portion 67 of the front surface 61 of the barrier film 6 overlaps the protruding portion (convex portion) 64 of the back surface 62 of the barrier film 6, and the concave portion of the back surface 62 of the barrier film 6 68 may overlap the protruding portion (convex portion) 63 of the surface 61 of the barrier film 6.

According to this configuration, a portion having a large thickness and a large rigidity and a portion having a small thickness and a small rigidity are less likely to occur unbalanced in the barrier film 6. Therefore, the springiness of the barrier film 6 can be increased, and the effect of suppressing the occurrence of wrinkles can be increased.

Further, the thickness of the barrier film 6 may be 110 μm or less.

As described above, when the thickness of the barrier film 6 is 110 μm or less, the rigidity of the barrier film 6 becomes small, wrinkles are more likely to occur in the barrier film 6, and when the thickness of the barrier film 6 is 25 μm or less, further. Wrinkles are more likely to occur on the barrier film 6. Therefore, when the thickness of the barrier film 6 is 110 μm or less, the effect of suppressing the formation of wrinkles on the barrier film 6 can be increased by providing the barrier film 6 with irregularities. Further, when the thickness of the barrier film 6 is 25 μm or less, the effect of suppressing the formation of wrinkles on the barrier film 6 can be remarkable by providing the barrier film 6 with irregularities.

Further, the unevenness may be formed on the barrier film 6 by embossing.

According to this configuration, unevenness can be easily and inexpensively formed on the barrier film 6.

The present disclosure is not limited to the above-described embodiment and its modifications, and various improvements and changes can be made within the scope of the claims of the present application and the equivalent scope thereof.

For example, in the above embodiment, the case where the first base material 12 to the second base material 13 are integrated at once and the solar cell module 50 is integrally formed by vacuum laminating has been described. However, as shown in FIG. 12, that is, the figure illustrating the method for manufacturing the solar cell module 110, the solar cell module 110 may be formed by the separation molding described below.

Specifically, the back side original base material 25 which is the base material of the second base material 103, the back side sheet material 41 constituting the back side portion of the sealing layer 105 with respect to the solar cell 11, the solar cell 11 and the wiring material (in FIG. 12). A pair of vacuum laminating devices is formed by laminating a laminated structure 180 in which a front sheet material 42 constituting a front side portion of the sealing layer 105 with respect to the solar cell 11 and a film base material 43 provided with irregularities are laminated in this order. After arranging between the silicone rubbers (diaphragms) of the above, vacuum lamination may be performed at a high temperature to form an integral laminated structure 190 that does not include the first base material 102. Then, after that, the first base material 102 is bonded to the film 106 side in the thickness direction of the laminated structure 190 at room temperature via the gel-like low elasticity resin layer 107 to form the solar cell module 110. You may. Further, the bonding may be performed at about 130 ° C. As a result, the adhesion between the first base material 102 and the low elasticity resin layer 107, and the adhesion between the low elasticity resin layer 107 and the film base material 43 is improved.

More specifically, the method for manufacturing the solar cell module 110 includes a plurality of solar cells 11, a first base material 102 arranged on a light receiving side in which light is mainly incident on the plurality of solar cells 11, and a plurality of suns. Even in the method for manufacturing a solar cell module, the method includes a second base material 103 provided on the back side of the battery cell 11 opposite to the light receiving side, and a sealing layer 105 for sealing a plurality of solar cell cells 11. Good. Further, in the method of manufacturing the solar cell module 110, a plurality of front side sheet materials (light receiving side sheet materials) 42, which are the original materials of the light receiving side sealing layer located on the light receiving side of the solar cell 11 in the sealing layer 105. The back side sheet material 41 which is the base material of the back side sealing layer located on the back side of the solar cell 11 and the sealing layer 105 and the back side base material 25 which is the base material of the second base material 103. May be laminated in this order. Then, after that, the front side sheet material 42 and the back side sheet material 41 are melted, and the front side sheet material 42 and the back side sheet material 41 are fused with the plurality of solar cell 11 sandwiched between them, and the back side sheet material 41 and the back side are fused. By adhering the original base material 25, a laminated structure 190 in which a plurality of solar cell 11, the sealing layer 105, and the second base material 103 are integrated may be formed. Then, after that, the first base material 102 may be bonded to the laminated structure 190 on the side opposite to the second base material 103 in the thickness direction via a material having adhesiveness. Further, the solar cell module 110 may include a film 106 between the first base material 102 and the sealing layer 105. Then, after arranging the film base material 43 which is the base material of the film 106 on the side opposite to the solar cell 11 of the front side sheet material 42, the front side sheet material 42 and the back side sheet material 41 may be melted. In this way, the laminated structure 190 having the film 106 on the opposite side of the sealing layer 105 from the second base material 103 may be formed. Further, the film 106 of the solar cell module 110 may have a tensile elastic modulus lower than that of the first base material 102. Further, the film base material 43 may have irregularities.

Next, the superiority of the manufacturing method of the solar cell module 110 of the modified example will be described by comparing it with the manufacturing method of the solar cell module 410 of the second reference example. FIG. 13 is a diagram illustrating a method of manufacturing the solar cell module 410 of the second reference example. As shown in FIG. 13, when the front base material 415 to the back side base base material 425 are integrated at once by high temperature laminating processing, the first base material is affected by the deformation of the back side layer during the laminating process. The 402 may be deformed so that its surface 420 is wavy. In particular, when the sealing layer is made of a resin material in which polymers are linked by cross-linking, the cross-linking temperature of the sealing resin tends to be higher than the heat resistant temperature of the front base material 415. Therefore, the first base material 402 is easily affected by heat during the laminating process, and the surface 420 of the first base material 402 is easily deformed in a wavy manner.

On the other hand, in the method of manufacturing the solar cell module 110 shown in FIG. 12, since the first base material 102 is bonded to the laminated structure 190 via the low elasticity resin layer 107 at room temperature, the first base material 102 is laminated. Not affected by processing. Therefore, it is possible to suppress or prevent the surface of the first base material 102 from being deformed in a wavy manner.

Needless to say, the method for manufacturing the solar cell module 110 described with reference to FIG. 12 can be applied to the method for manufacturing the solar cell module including a film having no unevenness. Further, the method for manufacturing the solar cell module 110 described with reference to FIG. 12 can also be applied to the method for manufacturing the solar cell module 210 that does not include a film.

FIG. 14 is a diagram illustrating the application of the method for manufacturing the solar cell module 110 shown in FIG. 12 to the manufacturing of the solar cell module 210 that does not include a film.

As shown in FIG. 14, in this manufacturing method, the back side original base material 225, which is the base material of the second base material 203, the back side sheet material 241 forming the back side portion of the sealing layer 205 with respect to the solar cell 11, and the solar cell. Cell 11 and wiring material (not shown in FIG. 14), front side sheet material (light receiving side sheet material) 242 constituting the front side portion of the sealing layer 205 with respect to the solar cell 11, and a sheet member having a non-adhesive coating applied to the outer surface. A laminated structure 280 in which 249 is laminated in this order is arranged between a pair of silicone rubbers (diaphragms) of a vacuum laminating apparatus, and then vacuum laminating is performed at a high temperature to achieve an integral structure that does not include the first base material 202. A laminated structure 290 is formed. Then, after the sheet member 249 is peeled off, the first base material 202 is placed on the side opposite to the second base material 203 side in the thickness direction of the laminated structure 290 at room temperature, and the gel-like low elasticity resin layer 207 is placed. The solar cell module 210 is formed by bonding the solar cell modules 210 together.

According to the manufacturing method of this modification, the front side sheet material 242 and the back side sheet material 241 are placed in a state where the sheet member 249 is arranged on the side opposite to the solar cell 11 side of the front side sheet material (light receiving side sheet material) 242. Melt. Therefore, in the sheet member 249, it is possible to suppress or prevent the surface of the front side sheet material 242 from being deformed in a wavy manner by laminating. Therefore, as in the method shown in FIG. 12, the first base material 202 is not affected by the laminating process performed at high temperature and high pressure, and deformation of the surface of the first base material 202 can be suppressed or prevented. ..

10 Solar cell module, 11 Solar cell, 12 1st base material, 13 2nd base material, 14, 14A, 14B sealing layer, 15 barrier layer, 16, 16A, 16B barrier film, 18 seams, 20 buffer layers, 21,21A, 21B cushioning film, 22 boundaries, 23 concealing layers, 30 wiring materials, 31,32 crossover wiring materials, 33 strings, 34 terminal boxes

Claims (11)

With multiple solar cells
A first base material made of resin, which is provided on the first surface side of the plurality of solar cells and has a curved shape convex in the direction opposite to the plurality of solar cells.
A second base material provided on the second surface side of the solar cell and having a curved shape convex in the direction of the first base material,
A sealing layer filled between the first base material and the second base material,
A buffer layer provided between the first base material and the plurality of solar cells and having a lower shear modulus than the sealing layer,
With
The solar cell module is composed of a plurality of buffer films arranged in a sheet shape. There is a gap between the adjacent cushioning films,
The solar cell module according to claim 1, wherein the gap is filled with the sealing layer. The solar cell module according to claim 1, wherein the plurality of cushioning films are arranged adjacent to each other with their ends overlapping each other in the thickness direction of the module. The solar cell module according to any one of claims 1 to 3, wherein at least one of the end portions of the cushioning film is provided at a position where the gap between the solar cell cells overlaps with the thickness direction of the module. The solar cell module according to any one of claims 1 to 4, further comprising a concealing layer covering an end portion of the cushioning film between the first base material and the cushioning layer. The plurality of cushioning films are arranged in the X direction, which is one of the surface directions of the first base material.
The solar cell module according to any one of claims 1 to 5, wherein the length W ₂ in the X direction of the plurality of buffer films is the following length W ₁ or less of the first base material.
Here, the length W ₁ is
Arbitrary points aligned in the Y direction of the first base material orthogonal to the X direction are A1, A2,
L ₁ the length of a line connecting the shortest distance to A1, A2 along the surface of the first substrate alpha, linear alpha,
B1, B2, points drawn by drawing a perpendicular line γ of the same length along the surface of the first base material with respect to the line α from A1 and A2.
Along said surface of the first substrate a line connecting the B1, B2 in the shortest distance beta, the length of the line beta L _2,
Then, it is the length of the perpendicular line γ when the length L ₂ of the line β is 99.0% or more of the length L ₁ of the line α. The solar cell module according to any one of claims 1 to 6, wherein the plurality of cushioning films have a shear modulus of 0.1 MPa or less. The solar cell module according to any one of claims 1 to 7, further comprising a barrier layer having a lower oxygen transmittance than that of the first base material between the buffer layer and the plurality of solar cell cells. A plurality of strings including the plurality of solar cells, which are arranged at intervals in the direction of the first curve, which is the extending direction of the first curve convex on the light receiving side, and
A barrier film provided between the first base material and the plurality of solar cells and having a coefficient of linear expansion smaller than that of the first base material.
With more
The solar cell module according to any one of claims 1 to 8, wherein the barrier film has irregularities in a portion between two adjacent strings in the first curve direction. The unevenness is provided on both the front surface of the barrier film on the light receiving side and the back surface of the back side of the film.
When viewed from the thickness direction of the barrier film, the concave portion on the front surface of the barrier film overlaps the convex portion on the back surface of the barrier film, and the concave portion on the back surface of the barrier film is the front surface of the barrier film. The solar cell module according to claim 9, which overlaps the convex portion of the film. The solar cell module according to claim 9 or 10, wherein the thickness of the barrier film is 110 μm or less.

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