WO2019176646A1 - Solar cell module - Google Patents

Abstract

A solar cell module (100) includes, in order from the light-receiving surface side, the following: a surface protective substrate (20) made of a resin; a gel-like polymer layer (22); a first sealing material layer (26); a photoelectric conversion unit; a second sealing material layer (28); and a backside protective layer (32) provided with a low heat expansion component aligned in one direction. The tensile elastic modulus of the gel-like polymer layer (22) is smaller than the tensile elastic modulus of any of the surface protective substrate (20), the first sealing material layer (26), and the second sealing material layer (28). The heat expansion coefficient of the backside protective layer (32) in one direction is smaller than the heat expansion coefficient of the surface protective substrate (20). The backside protective layer (32) is configured such that the heat expansion coefficient in the one direction and the heat expansion coefficient in another direction which is perpendicular to the one direction are mutually different.

Description

Solar cell module

The present invention relates to a solar cell module.

The solar cell module basically includes a first substrate (surface protective substrate), a first resin layer (sealing material layer), a photoelectric conversion unit, and a second resin layer (sealing material layer). And a second substrate (back surface protection substrate) in this order. That is, the photoelectric conversion unit is protected by covering the front and back surfaces of the photoelectric conversion unit with the first substrate and the first resin layer, and the second resin layer and the second substrate. And in a photoelectric conversion part, a several photovoltaic cell is arranged in matrix form, and adjacent photovoltaic cells are electrically connected by tab wiring. In this manner, for example, the output voltage is increased by electrically connecting the plurality of solar cells with the plurality of tab wirings.

In addition, conventionally, a glass substrate has been generally used as a protective substrate for a solar cell module. However, in recent years, resin substrates have been used instead of glass substrates for weight reduction.

As a manufacturing method of the above-mentioned solar cell module, after laminating a surface protection substrate, a sealing material layer, a photoelectric conversion part, a sealing material layer, and a back surface protection substrate, each layer is formed by pressurizing while heating to 100 ° C or more. A method of bonding is common. However, when the surface protection substrate and the back surface protection substrate are made of resin, when the surface protection substrate and the back surface protection substrate are cooled to room temperature after heating, the surface protection substrate and the back surface protection substrate are greatly contracted. At this time, since the surface protection substrate and the back surface protection substrate are different in material and / or thickness, there is a difference in shrinkage rate, and as a result, there is a problem that the obtained solar cell module warps in a concave shape.

In order to solve such a problem, Patent Document 1 discloses a method of predicting the warpage of the solar cell module and imparting the warpage in the opposite direction to the warpage. Specifically, Patent Document 1 discloses a method of manufacturing a solar cell module by heating and pressing under vacuum in a state where a transparent plate, a sealing material, and solar cells are stacked. . And in the said manufacturing method, it heats and pressurizes in the state which was warped contrary to the curvature of the solar cell module which is set | placed at normal temperature after heating and the generation | occurrence | production of curvature is estimated.

Patent Document 2 discloses a method of suppressing concave warpage by making the thermal expansion coefficients of the front surface protection substrate and the rear surface protection substrate substantially equal. Specifically, in Patent Document 2, a solar cell, a translucent plastic surface material bonded to the light receiving surface side of the solar cell, and a surface material and a thermal expansion coefficient bonded to the back surface side of the solar cell. Discloses a solar cell module composed of a plastic backing material having substantially the same size.

JP 2010-258380 A Japanese Utility Model Publication No. 63-43457

However, in the manufacturing method of Patent Document 1, it is necessary to predict the amount of warpage when the solar cell module reaches room temperature, and to specify the material and shape for canceling the warpage, so that enormous analysis and trial and error are performed. There was a need. Moreover, in the solar cell module of patent document 2, although the curvature resulting from a surface protection board | substrate and a back surface protection board | substrate is suppressed, by receiving the influence of the sealing material and photovoltaic cell which are arrange | positioned inside, it is a concave curvature. There was a risk of occurrence.

The present invention has been made in view of such problems of the conventional technology. And the objective of this invention is providing the solar cell module which can suppress concave curvature by a simple method.

In order to solve the above problems, a solar cell module according to a first aspect of the present invention includes, in order from the light-receiving surface side, a resin-made surface protective substrate, a gel polymer layer, a first sealing material layer, , A photoelectric conversion unit, a second sealing material layer, and a back surface protective layer including a low thermal expansion component oriented in one direction. The tensile elastic modulus of the gel polymer layer is smaller than any tensile elastic modulus of the surface protective substrate, the first sealing material layer, and the second sealing material layer. The back surface protective layer has a unidirectional thermal expansion coefficient smaller than that of the surface protective substrate. In the back surface protective layer, the thermal expansion coefficient in one direction is different from the thermal expansion coefficient in the other direction perpendicular to the one direction.

The moving body according to the second aspect of the present invention includes a solar cell module.

FIG. 1 is a plan view showing the solar cell module according to the first embodiment. FIG. 2 is a schematic view showing a cross section of the solar cell module taken along line II-II in FIG. FIG. 3 is a schematic view showing a cross section of a solar cell module having a form different from that of FIG. Fig.4 (a) is a top view which shows the state which the fiber material extended | stretched to one direction in the back surface protective layer. FIG. 4B is a side view showing a state where the light receiving surface side of the solar cell module is convex. Fig.5 (a) is a top view which shows the state which the fiber material extended | stretched to the vertical direction and the horizontal direction in the back surface protective layer. FIG. 5B is a side view showing a state where the light receiving surface side of the solar cell module is concave. FIG. 6 is a side view showing a solar cell module using a back surface protective layer having slits. FIG. 7 is a plan view showing a back surface protective layer of the solar cell module shown in FIG. FIG. 8 is a plan view showing another example of the back surface protective layer having slits. FIG. 9 is a plan view showing the solar cell module according to the second embodiment. FIG. 10A is a schematic view showing a cross section of the solar cell module taken along line XA-XA in FIG. FIG. 10B is a schematic view showing a cross section of the solar cell module taken along line XB-XB in FIG. FIG. 11 is a plan view showing a solar cell module according to the third embodiment. FIG. 12 is a schematic view showing a cross section of the solar cell module taken along line XII-XII in FIG. FIG. 13A is a schematic view showing a cross section of the solar cell module taken along line XIIIA-XIIIA in FIG. FIG. 13B is a schematic view showing a cross section of the solar cell module taken along line XIIIB-XIIIB in FIG. FIG. 14 is a cross-sectional view showing a mode in which convex ribs are provided in the extending portion of the surface protection substrate. FIG. 15 is a schematic view showing a cross section of the solar cell module according to the third embodiment. FIG. 16 is a schematic view showing a cross section of the solar cell module according to the third embodiment. FIG. 17 is a plan view showing a solar cell module according to the fourth embodiment. FIG. 18A is a schematic view showing a cross section of the solar cell module taken along line XVIIIA-XVIIIA in FIG. FIG. 18B is a schematic view showing a cross section of the solar cell module taken along line XVIIIB-XVIIIB in FIG. FIG. 19 is a plan view showing a state in which a frame member is provided around the surface protection substrate in the solar cell module of FIG. FIG. 20A is a schematic view showing a cross section of the solar cell module taken along line XXA-XXA in FIG. FIG. 20B is a schematic view showing a cross section of the solar cell module taken along line XXB-XXB in FIG. FIG. 21A is a schematic diagram showing a cross section taken along line XVIIIA-XVIIIA in FIG. 17, regarding another example of the solar cell module according to the fourth embodiment. FIG. 21B is a schematic view showing a cross section taken along line XVIIIB-XVIIIB in FIG. 17, regarding another example of the solar cell module according to the fourth embodiment. FIG. 22A is a schematic diagram showing a cross section taken along line XVIIIA-XVIIIA in FIG. 17, regarding another example of the solar cell module according to the fourth embodiment. FIG. 22B is a schematic view showing a cross section taken along line XVIIIB-XVIIIB in FIG. 17, regarding another example of the solar cell module according to the fourth embodiment. FIG. 23A is a schematic view showing a cross section taken along line XVIIIA-XVIIIA in FIG. 17, regarding another example of the solar cell module according to the fourth embodiment. FIG. 23B is a schematic diagram showing a cross section taken along line XVIIIB-XVIIIB in FIG. 17, regarding another example of the solar cell module according to the fourth embodiment. FIG. 24 is a cross-sectional view showing the configuration of the solar cell module according to Example 1-1. FIG. 25 shows the evaluation results of the solar cell module in Example 1-1. Fig.25 (a) is a top view of the back surface protective layer used with the solar cell module. FIG. 25 (b) is a side view showing the result of obtaining the displacement when the solar cell module is cooled along the fiber direction B. FIG. FIG. 25 (c) is a side view showing the result of obtaining the displacement when the solar cell module is cooled along the direction C perpendicular to the fiber direction B. FIG. 25 (d) is a graph showing the relationship between the amount of vertical displacement and temperature at the right end of the solar cell module. FIG. 26 shows the evaluation results of the solar cell module in Example 1-2. Fig.26 (a) is a top view of the back surface protective layer used with the solar cell module. FIG.26 (b) is a perspective view which shows the result of having calculated | required the displacement at the time of cooling a solar cell module. FIG.26 (c) is a graph which shows the relationship between the amount of displacements of the up-down direction in the right end of a solar cell module, and temperature. FIG. 27 shows the evaluation results of the solar cell module in Comparative Example 1. Fig.27 (a) is a top view of the back surface protective layer used with the solar cell module. FIG. 27B is a perspective view showing a result of obtaining a displacement when the solar cell module is cooled. FIG. 27C is a graph showing the relationship between the amount of vertical displacement and temperature at the right end of the solar cell module. FIG. 28 shows the evaluation results of the solar cell module in Example 1-3. FIG. 28A is a side view showing the result of obtaining the displacement when the solar cell module is cooled along the fiber direction B. FIG. FIG. 28B shows an enlarged right end in the case where the solar cell module is cooled and deformed. FIG. 29 is a schematic diagram showing the solar cell modules of Example 2 and Comparative Example 2 used in the simulation. 29A is a plan view showing the solar cell module, FIG. 29B is a view of the solar cell module of FIG. 29A viewed from the right side, and FIG. 29C is FIG. It is the figure which looked at the solar cell module of a) from the lower surface. FIG. 30 is a perspective view showing displacement when the solar cell modules of Example 2 and Comparative Example 2 are cooled in the simulation.

Hereinafter, the solar cell module according to the present embodiment will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

[Solar Cell Module of First Embodiment]
FIG. 1 is a plan view showing a solar cell module 100 according to the first embodiment. As shown in FIG. 1, a rectangular coordinate system composed of an x-axis, a y-axis, and a z-axis is defined. The x axis and the y axis are orthogonal to each other in the plane of the solar cell module 100. The z axis is perpendicular to the x axis and the y axis and extends in the thickness direction of the solar cell module 100. Further, the positive directions of the x-axis, y-axis, and z-axis are each defined in the direction of the arrow in FIG. 1, and the negative direction is defined in the direction opposite to the arrow. Of the two main surfaces forming the solar cell module 100 and parallel to the xy plane, the main plane disposed on the positive side of the z-axis is a “light-receiving surface”. The main plane disposed on the negative direction side of the z-axis is the “back surface”. The “light receiving surface” means a surface on which light is mainly incident, and the “back surface” means a surface opposite to the light receiving surface. Further, the positive direction side of the z-axis may be referred to as “light-receiving surface side”, and the negative direction side of the z-axis may be referred to as “back surface side”.

The solar cell module 100 has a plurality of solar cells 10, a plurality of tab wires 12, and a plurality of connection wires 14. Each of the plurality of solar cells 10 absorbs incident light and generates photovoltaic power. The solar battery cell 10 is formed of a semiconductor material such as crystalline silicon, gallium arsenide (GaAs), or indium phosphide (InP). The structure of the solar battery cell 10 is not particularly limited, but here, as an example, it is assumed that crystalline silicon and amorphous silicon are stacked. Although omitted in FIG. 1, a plurality of finger electrodes extending in the x direction in parallel to each other and a plurality of finger electrodes extending in the y direction so as to be orthogonal to the plurality of finger electrodes are provided on the light receiving surface and the back surface of each solar battery cell 10. For example, two bus bar electrodes are provided. The bus bar electrode connects each of the plurality of finger electrodes.

The plurality of solar cells 10 are arranged in a matrix on the xy plane. Here, four solar cells 10 are arranged in the x direction, and five solar cells 10 are arranged in the y direction. In addition, the number of the photovoltaic cells 10 arranged in the x direction and the number of the photovoltaic cells 10 arranged in the y direction are not limited to these. The five solar cells 10 arranged side by side in the y direction are connected in series by the tab wiring 12 to form one solar cell string 16. Furthermore, as described above, since the four solar cells 10 are arranged in the x direction, four solar cell strings 16 extending in the y direction are arranged in parallel in the x direction. The solar cell string 16 refers to a combination of a plurality of solar cells 10 and a plurality of tab wires 12.

In order to form the solar cell string 16, the tab wiring 12 electrically connects the bus bar electrode on one light receiving surface side of the adjacent solar cells 10 and the bus bar electrode on the other back surface side. That is, the adjacent solar cells 10 are electrically connected to each other by the tab wiring 12. The tab wiring 12 is an elongated metal foil. For example, a copper foil coated with solder or silver is used. Resin is used for connection between the tab wiring 12 and the bus bar electrode. This resin may be either conductive or non-conductive. In the latter case, the tab wiring 12 and the bus bar electrode are electrically connected by direct contact. The tab wiring 12 and the bus bar electrode may be connected by using solder instead of resin.

Furthermore, a plurality of connection wires 14 extend in the x direction on the positive side and the negative side of the y-axis of the solar cell string 16. The connection wiring 14 electrically connects two adjacent solar cell strings 16.

In the above configuration, each of the solar battery cell 10 and the solar battery string 16 may be a “photoelectric converter”, and a combination of the plurality of solar battery strings 16 and the connection wiring 14 is a “photoelectric converter”. Also good. A frame member (not shown) may be attached to the outer edge of the solar cell module 100. The frame member protects the outer edge of the solar cell module 100 and is used when the solar cell module 100 is installed on a roof or the like.

FIG. 2 is a cross-sectional view showing a part of the solar cell module 100 taken along the line II-II in FIG. The solar cell module 100 includes a solar cell string 16 including solar cells 10 and tab wires 12, connection wires 14, a surface protection substrate 20, a gel polymer layer 22, a first sealing material layer 26, and a second seal. A stopper layer 28 and a back surface protective layer 32 are provided. 2 corresponds to the light receiving surface (front surface) side, and the lower side corresponds to the back surface side. Therefore, in the solar cell module 100, in order from the light receiving surface side, the surface protection substrate 20, the gel polymer layer 22, the first sealing material layer 26, and the photoelectric conversion unit (solar cell 10, tab wiring 12, The connection wiring 14), the second sealing material layer 28, and the back surface protective layer 32 are laminated.

2, a back surface protective layer 32 is provided on the back surface of the solar cell module 100. As shown in FIG. 2, since the thickness of the back surface protective layer 32 is thinner than that of the front surface protective substrate 20, the back surface protective layer 32 has small rigidity and is easily deformed. In addition, the one-way thermal expansion coefficient of the back surface protection layer 32 is smaller than the thermal expansion coefficient of the front surface protection substrate 20, and the one-way expansion and contraction of the back surface protection layer 32 due to the temperature change is the expansion and contraction of the front surface protection substrate 20. Smaller than.

On the other hand, the gel-like polymer layer 22 has a lower tensile elastic modulus than any one of the surface protective substrate 20, the first sealing material layer 26, and the second sealing material layer 28, and has a high flexibility. . Therefore, even when the surface protective substrate 20 expands and contracts due to a temperature change, the lower gel-like polymer layer 22 adjacent to the surface protective substrate 20 has a small tensile elastic modulus, and therefore can follow the expansion and contraction of the surface protective substrate 20. it can.

From the above, even if the surface protective substrate 20 expands and contracts due to temperature change, the gel-like polymer layer 22 follows the expansion and contraction, so that the generation of stress due to the expansion and contraction of the surface protective substrate 20 is alleviated. Further, the back surface protective layer 32 has a thermal expansion coefficient in a predetermined direction smaller than that of the front surface protective substrate 20, and is difficult to expand and contract due to a temperature change. Therefore, it is suppressed that either one tends to expand and contract on the front and back of the solar cell module 100, and the balance of stress is maintained. As a result, generation | occurrence | production of curvature and an internal stress can be prevented.

In addition, since the back surface protective layer 32 is thin, it has a small rigidity and is easily deformed, and therefore has excellent followability to a curved surface shape. Furthermore, by reducing the thickness of the back surface protective layer 32, it is possible to reduce the weight as compared with a substrate-like substrate (back surface protective substrate) equivalent to the surface protective substrate 20.

(Surface protection substrate)
The surface protection substrate 20 is a substrate that is located on the sunlight receiving side of the solar cell module 100 and is made of a transparent resin. Examples of the transparent resin constituting the surface protective substrate 20 include polyethylene (PE), polypropylene (PP), cyclic polyolefin, polycarbonate (PC), polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE), and polystyrene (PS). ), At least one selected from the group consisting of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). Among these, it is preferable to use polycarbonate (PC) as the surface protection substrate 20. Polycarbonate (PC) is excellent in impact resistance and translucency, and is suitable for protecting the surface of the solar cell module 100.

Further, the surface protective substrate 20 may include a hard coat layer made of silicone or acrylic urethane on the surface. Furthermore, the surface protective substrate 20 or the hard coat layer may contain an ultraviolet absorber, a gloss adjusting agent, and an antireflection component.

The thickness of the surface protective substrate 20 is not particularly limited, but is preferably 2 mm to 6 mm, and more preferably 3 mm to 5 mm. As will be described later, the thickness of the back surface protective layer 32 is preferably 10% or less of the thickness of the surface protective substrate 20. And the mechanical strength which falls because the thickness of the back surface protective layer 32 is thin is ensured by the surface protective substrate 20 being thick. By setting the thickness of the surface protection substrate 20 in such a range, the solar cell module 100 can be appropriately protected, and incident light can efficiently reach the photoelectric conversion unit (solar cell 10).

The tensile elastic modulus of the surface protective substrate 20 is preferably 1.0 GPa to 10.0 GPa, and more preferably 2.3 GPa to 2.5 GPa. By setting the tensile elastic modulus of the surface protection substrate 20 in such a range, the surface of the solar cell module 100 can be appropriately protected. The tensile modulus in the present specification can be measured, for example, according to JIS K7161-1 (Plastics-Determination of tensile properties-Part 1: General rules) as follows. The tensile modulus is a value when the temperature is 23 ± 2 ° C. and the humidity is 50 ± 10%.
Et = (σ2−σ1) / (ε2−ε1) (1)
In the above formula (1), Et is the tensile modulus (Pa), σ1 is the stress (Pa) at the strain ε1 = 0.0005, and σ2 is the stress (Pa) at the strain ε2 = 0.0025.

The total light transmittance of the surface protective substrate 20 is preferably 80% or more, more preferably 90 to 100%. By setting the total light transmittance of the surface protective substrate 20 within this range, light can efficiently reach the photoelectric conversion unit (solar cell 10). The total light transmittance in this specification can be measured by, for example, JIS K7361-1 (Plastic—Test method for total light transmittance of transparent material—Part 1: Single beam method).

The thermal expansion coefficient (linear expansion coefficient) of the surface protective substrate 20 is not particularly limited, but can be 40 to 110 (× 10 ⁻⁶ K ⁻¹ ). In addition, the thermal expansion coefficient (linear expansion coefficient) in this specification can be measured by JIS K7197: 2012 (linear expansion coefficient test method by thermomechanical analysis of plastics).

(Gel polymer layer)
The gel-like polymer layer 22 is a layer formed of a gel-like polymer rich in flexibility, and is located between the surface protective substrate 20 and the first sealing material layer 26. The gel polymer layer 22 has flexibility, and follows the expansion and contraction when the surface protection substrate 20 expands and contracts. Therefore, it is possible to prevent the stress due to the expansion and contraction of the surface protection substrate 20 from being transmitted to the photoelectric conversion unit. That is, the stress due to the expansion and contraction of the surface protective substrate 20 can be relaxed by the gel-like polymer layer 22.

As the material constituting the gel polymer layer 22, various gels can be used. The gel is not particularly limited, but is classified into a gel containing a solvent and a gel not containing a solvent. As the gel containing a solvent, a hydrogel whose dispersion medium is water or an organogel whose dispersion medium is an organic solvent can be used. Moreover, as a gel containing a solvent, it is possible to use either a polymer gel having a number average molecular weight of 10,000 or more, an oligomer gel having a number average molecular weight of 1,000 or more and less than 10,000, or a low molecular gel having a number average molecular weight of less than 1,000. it can. The gel polymer is preferably composed of at least one selected from the group consisting of silicone resin, urethane resin, acrylic resin and styrene resin.

The gel-like polymer layer 22 preferably has a thickness of 5 to 70% with respect to the thickness of the surface protective substrate 20, and more preferably has a thickness of 10 to 50%. Since the gel-like polymer layer 22 has such a thickness, stress due to expansion / contraction of the surface protective substrate 20 can be sufficiently relieved.

The tensile elastic modulus of the gel polymer layer 22 is preferably 0.1 kPa or more and less than 5 MPa, more preferably 1 kPa or more and 1 MPa or less. When the tensile elastic modulus of the gel polymer layer 22 is in such a range, the stress due to expansion / contraction of the surface protective substrate 20 can be sufficiently relaxed.

The total light transmittance of the gel polymer layer 22 is preferably 80% or more, and preferably 90 to 100%. By setting the total light transmittance of the gel polymer layer 22 within this range, light can efficiently reach the photoelectric conversion portion (solar cell 10).

(First sealing material layer, second sealing material layer)
The 1st sealing material layer 26 and the 2nd sealing material layer 28 seal a photoelectric conversion part. The first sealing material layer 26 is disposed on the negative direction side (lower side) of the z-axis of the surface protection substrate 20, and the second sealing material layer 28 is the positive direction side of the back surface protection layer 32 on the z-axis. (Upper side).

As the first sealing material layer 26, for example, a gel having a tensile modulus of 0.001 MPa to 1 MPa and a loss coefficient of 0.1 to 0.52 is used. As such a gel, for example, at least one selected from the group consisting of silicone gel, acrylic gel, and urethane gel can be used. For silicone gel, the tensile modulus is about 0.022 MPa. The loss coefficient is a ratio G ″ / G ′ between the storage shear modulus (G ′) and the loss shear modulus (G ″) and is represented by tan δ. The loss factor indicates how much energy the material absorbs when the material deforms. The larger the value of tan δ, the more energy is absorbed. This loss factor is measured by a dynamic viscoelasticity measuring device.

The first sealing material layer 26 is formed of a rectangular sheet material having translucency and having a surface with slightly small dimensions in the xy plane of the surface protection substrate 20. The first sealing material layer 26 may be liquid.

On the other hand, as the second sealing material layer 28, for example, a thermoplastic resin such as a resin film such as EVA (ethylene-vinyl acetate copolymer), PVB (polyvinyl butyral), polyimide, or the like is used. As the second sealing material layer 28, a thermosetting resin may be used. As the second sealing material layer 28, EVA is preferably used. For EVA, the tensile modulus is 0.01 to 0.25 GPa and the loss factor is about 0.05.

The second sealing material layer 28 is formed of a rectangular sheet material having translucency and having a surface having a slightly small size in the xy plane of the surface protection substrate 20.

Here, as shown in FIG. 2, the back surface protective layer 32 which is thin and has low rigidity is provided on the back surface of the solar cell module 100. The second sealing material layer 28 located on the back surface protective layer 32 side is easily affected by stress from the back surface protective layer 32, and there is a concern that the tab wiring 12 may be disconnected. Therefore, in the solar cell module 100, the tensile elastic modulus of the second sealing material layer 28 is preferably larger than the tensile elastic modulus of the first sealing material layer 26. Thus, by increasing the tensile elastic modulus of the second sealing material layer 28, that is, making it difficult to deform, the tab wiring 12 becomes difficult to displace, and disconnection of the tab wiring 12 due to stress from the back surface protection layer 32 is prevented. Can be suppressed.

(Middle layer)
The solar cell module 100 includes a surface protection substrate 20, a gel polymer layer 22, a first sealing material layer 26, a photoelectric conversion unit, a second sealing material layer 28, and a back surface protection layer 32. ing. However, the solar cell module 100 includes the intermediate layer 24 between at least one of the gel-like polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. , 30 is preferably included. Moreover, it is preferable that the intermediate layers 24 and 30 are layers whose tensile elastic modulus is larger than any of the first sealing material layer 26 and the second sealing material layer 28.

As described above, in the first embodiment, since the back surface protective layer 32 is relatively thin, it cannot be said that the mechanical strength is high, and there is a concern that the impact resistance on the back surface side is lowered. That is, there is a concern that the solar battery cell 10 may be damaged due to an impact received on the back side when the solar battery module 100 is transported or installed. Therefore, a medium having a relatively large tensile elastic modulus is provided between at least one of the gel-like polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. By providing the layer, impact resistance can be improved.

In FIG. 3, the intermediate layers 24 and 30 are provided both between the gel polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. Is shown. The solar cell module shown in FIG. 3 is different from the configuration shown in FIG. 2 in that the intermediate layers 24 and 30 are provided, but the other configurations are the same. From the viewpoint of improving the strength, it is preferable to provide two intermediate layers 24 and 30 as shown in FIG.

As described above, it is preferable that the intermediate layer 24 has a tensile elastic modulus larger than any of the first sealing material layer 26 and the second sealing material layer 28. Thereby, even when the surface protection substrate 20 expands and contracts, since the intermediate layer 24 does not follow the expansion and contraction of the surface protection substrate 20, it is possible to suppress the transmission of stress to the photoelectric conversion unit.

In the first embodiment, it is preferable that the thermal expansion coefficients of the intermediate layers 24 and 30 are smaller than the thermal expansion coefficients of the first sealing material layer 26 and the second sealing material layer 28. With such a configuration, even when the surface protection substrate 20 expands and contracts due to a temperature change, the intermediate layers 24 and 30 can relieve stress due to the expansion and contraction of the surface protection substrate 20.

The materials constituting the intermediate layers 24 and 30 are polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polycarbonate, polyacetal, acrylic resin, polyamide resin, ABS resin, ACS resin, AES. Examples thereof include resins, ASA resins, and copolymers thereof. The intermediate layers 24 and 30 may be made of fluorine resin such as polyvinyl fluoride (PVF), silicone resin, cellulose, nitrile resin, phenol resin, polyurethane, ionomer, polybutadiene, polybutylene, polymethylpentene, polyvinyl alcohol. , Polyarylate, polyether ether ketone, polyether ketone, polyether sulfone, polyimide and the like. The materials constituting the intermediate layers 24 and 30 may be used alone or in combination of two or more. Especially, as a material which comprises the intermediate | middle layers 24 and 30, a polyethylene terephthalate, a polyethylene naphthalate, a polybutylene terephthalate, a polycarbonate, and an acrylic resin are preferable. Further, the intermediate layers 24 and 30 may be made of the same material or different materials.

In the present embodiment, the intermediate layer 30 positioned between the second sealing material layer 28 and the back surface protective layer 32 preferably has electrical insulation. When a conductive base material such as CFRP is used as the base material of the back surface protective layer 32, the occurrence of leakage current may be a problem. Therefore, the leakage current can be insulated by disposing the intermediate layer 30 having electrical insulation between the second sealing material layer 28 and the back surface protective layer 32. As the material of the intermediate layer 30 used here, it is preferable to use a material having high electrical insulation among the materials of the intermediate layer.

The thickness of the intermediate layers 24 and 30 is preferably 1 μm to 200 μm, and more preferably 10 μm to 100 μm. When the intermediate layer 24 has such a thickness, transmission of stress due to expansion / contraction of the surface protective substrate 20 to the photoelectric conversion unit can be sufficiently suppressed. The thicknesses of the intermediate layers 24 and 30 may be the same or different.

The thermal expansion coefficients of the intermediate layers 24 and 30 are preferably 10 to 50 (× 10 ⁻⁶ K ⁻¹ ), and more preferably 15 to 30 (× 10 ⁻⁶ K ⁻¹ ). When the thermal expansion coefficient of the intermediate layer 24 is within this range, even when the surface protective substrate 20 expands and contracts due to heat, the expansion and contraction of the intermediate layer 24 is smaller than that of the surface protective substrate 20. Therefore, it can suppress that the stress by the expansion / contraction of the surface protection board | substrate 20 is transmitted to a photoelectric conversion part.

The total light transmittance of the intermediate layer 24 is preferably 80% or more, and preferably 90 to 100%. By setting the total light transmittance of the intermediate layer 24 within this range, light can efficiently reach the photoelectric conversion unit (solar cell 10).

Further, the tensile elastic modulus of the intermediate layers 24 and 30 is preferably 1.0 to 10.0 GPa, and more preferably 2 to 5 GPa. When the tensile elastic modulus of the intermediate layer 24 is within such a range, the stress due to expansion and contraction of the surface protective substrate 20 can be sufficiently relaxed.

It is preferable that a film having a water vapor transmission rate of 1.0 g / m ² · day or less is formed on at least one of the front and back surfaces of the intermediate layers 24 and 30. By forming such a film on the intermediate layers 24 and 30, the penetration of water vapor into the first sealing material layer 26 and the second sealing material layer 28 is blocked, and the sealing included in each sealing material layer Hydrolysis of the material can be suppressed. The water vapor transmission rate in this specification is determined by, for example, the infrared sensor method stipulated in Appendix B of JIS K7129: 2008 (Plastics-Films and Sheets-Method of determining water vapor transmission rate (instrument measurement method)). Can do.

A film having an oxygen permeability of 8.0 ml / m ² · day or less is preferably formed on at least one of the front and back surfaces of the intermediate layers 24 and 30. By forming such a film on the intermediate layers 24 and 30, the penetration of oxygen into the first sealing material layer 26 and the second sealing material layer 28 is blocked, and the sealing included in each sealing material layer Oxidation of the material can be suppressed. The oxygen transmission rate in this specification can be determined according to JIS K7126-1 (GC method).

The film provided on the intermediate layers 24 and 30 can be formed by a coating method or a vapor deposition method. The coating provided on the intermediate layers 24 and 30 is preferably composed of an inorganic composite material containing Si and O. Examples of such materials include siloxane compounds, among which polyorganosiloxane is preferable.

(Back protection layer)
In 1st embodiment, in order to protect the back surface side of the solar cell module 100, the back surface protection layer 32 as a back sheet is provided. And the back surface protective layer 32 has the low thermal expansion component orientated only in one direction. Specifically, as shown in FIG. 4A, the back surface protective layer 32 includes a base material 321 and a fiber material 322 that is provided inside the base material 321 and is a low thermal expansion component.

The base material 321 constituting the back protective layer 32 preferably contains a resin, and more preferably consists of a resin. Specifically, the base material 321 includes an epoxy resin, polyimide (PI), cyclic polyolefin, polycarbonate (PC), polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), polystyrene (PS), polyethylene terephthalate (PET). And at least one selected from the group consisting of polyethylene naphthalate (PEN).

The low thermal expansion component constituting the back surface protective layer 32 is preferably a material whose one-way thermal expansion coefficient in the back surface protective layer 32 is smaller than the thermal expansion coefficient of the surface protective substrate 20. Specifically, it is preferable to use a fiber material 322 as the low thermal expansion component of the back surface protective layer 32. Although the fiber material 322 is not particularly limited, at least one of an inorganic fiber made of an inorganic material and an organic fiber made of an organic material can be used. For example, at least one selected from the group consisting of carbon fiber, glass fiber, and aramid fiber Is preferably used.

The back surface protective layer 32 is preferably made of fiber reinforced plastic (FRP) having a base material 321 and a fiber material 322 which are matrix resins. As the fiber reinforced plastic, at least one selected from the group consisting of carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP), and aramid fiber reinforced plastic (AFRP) can be used. In addition, by using a carbon fiber reinforced plastic as the back surface protective layer 32, it is difficult to bend and a lightweight protective layer can be obtained.

In the solar cell module 100, the fiber material 322 which is a low thermal expansion component is oriented only in one direction. Specifically, as illustrated in FIG. 4A, the fiber material 322 included in the base material 321 is oriented along the x direction. Alternatively, the fiber material 322 included in the base material 321 is oriented along the y direction. By using a UD (UniDirection) material in which the fiber material 322 is aligned in one direction as the back surface protection layer 32, it is possible to suppress the solar cell module from warping in a concave shape.

More specifically, in the solar cell module 100, the back surface protective layer 32 has a thermal expansion coefficient in one direction smaller than that of the surface protective substrate 20. That is, when the fiber material 322 is oriented along the x direction, the back surface protective layer 32 has a thermal expansion coefficient in the x direction smaller than that of the surface protective substrate 20. Similarly, when the fiber material 322 is oriented along the y direction, the back surface protective layer 32 has a thermal expansion coefficient in the y direction smaller than that of the surface protective substrate 20.

Furthermore, in the back surface protective layer 32, the thermal expansion coefficient in one direction and the thermal expansion coefficient in the other direction perpendicular to the one direction are different from each other. That is, in the back surface protective layer 32, when the fiber material 322 is oriented along the x direction, the thermal expansion coefficient in the x direction and the thermal expansion coefficient in the y direction perpendicular to the x direction are different from each other. Yes. Similarly, in the back surface protective layer 32, when the fiber material 322 is oriented along the y direction, the thermal expansion coefficient in the y direction and the thermal expansion coefficient in the x direction are different from each other.

When the solar cell module 100 having such a configuration is cooled, the resin surface protection substrate 20 contracts along both the x direction and the y direction. On the other hand, since the back surface protective layer 32 has a thermal expansion coefficient in one direction (x direction or y direction) smaller than that of the surface protective substrate 20, the back surface protective layer 32 is in the one direction. Then, it does not shrink more than the surface protection substrate 20. Further, the back surface protective layer 32 is unlikely to contract in the one direction, but easily contracts in the other direction perpendicular to the one direction. As described above, the front surface protection substrate 20 contracts along both the x direction and the y direction, but the back surface protection layer 32 hardly contracts along the x direction or the y direction. Deformation into a concave shape can be suppressed.

Further, as shown in FIG. 4 (b), the solar cell module 100 of the first embodiment may have a curved surface shape in which the light receiving surface side is convex in a room temperature state. And even when such a convex solar cell module 100 is cooled, the front surface protection substrate 20 shrinks along both the x direction and the y direction, but the back surface protection layer 32 extends along the x direction or the y direction. It is hard to shrink. As a result, the convex solar cell module 100 can be maintained in a convex shape without being deformed into a concave shape.

On the other hand, for example, as shown in FIG. 5A, when the cross member in which the fiber material 322 is alternately oriented vertically and horizontally is used as the back surface protective layer, the solar cell module 100 is deformed into a concave shape. The possibility increases. That is, the cloth material has a small coefficient of thermal expansion in both the x direction and the y direction. Therefore, when the solar cell module using the cloth material as the back surface protection layer is cooled, the surface protection substrate 20 contracts along both the x direction and the y direction, but the back surface protection layer 32 is both in the x direction and the y direction. It is difficult to shrink. As a result, the solar cell module 100a is deformed into a concave shape as shown in FIG.

As described above, the solar cell module 100 includes, in order from the light receiving surface side, the resin surface protection substrate 20, the gel polymer layer 22, the first sealing material layer 26, the photoelectric conversion unit, and the second sealing. It has the stop material layer 28 and the back surface protective layer 32 provided with the low thermal expansion component orientated in one direction. The tensile elastic modulus of the gel polymer layer 22 is smaller than any tensile elastic modulus of the surface protective substrate 20, the first sealing material layer 26, and the second sealing material layer 28. The back surface protective layer 32 has a thermal expansion coefficient in one direction smaller than that of the surface protective substrate 20. In the back surface protective layer 32, the thermal expansion coefficient in one direction and the thermal expansion coefficient in the other direction perpendicular to the one direction are different from each other. As a result, the front surface protective substrate 20 contracts along both the x direction and the y direction, but the back surface protective layer 32 hardly contracts along the x direction or the y direction. Therefore, it is possible to suppress the solar cell module 100 from being deformed into a concave shape.

In addition, in the back surface protective layer 32, the low thermal expansion component does not need to extend along the x direction which is the short direction or the y direction which is the long direction. For example, the low thermal expansion component may be stretched at a predetermined angle from the x direction or the y direction.

Further, the back surface protective layer 32 may improve the reflectance by adding titanium oxide or the like to the base material 321 in order to increase the power generation efficiency on the back surface of the photoelectric conversion unit. Further, the surface of the back surface protective layer 32 may be plated.

In the solar cell module 100, the difference between the thermal expansion coefficient of the surface protective substrate 20 and the thermal expansion coefficient in the other direction perpendicular to the one direction in the back surface protective layer 32 is preferably as small as possible. In this case, the shrinkage rate in the x direction and the y direction of the front surface protection substrate 20 approximates the shrinkage rate in the other direction of the back surface protection layer 32. And as above-mentioned, in a back surface protective layer, since the thermal expansion coefficient of one direction is smaller than the thermal expansion coefficient of a surface protection board | substrate, a shrinkage rate is small. Therefore, when the solar cell module 100 is cooled, not only the front surface protection substrate 20 but also the other direction of the back surface protection layer 32 contracts, so that deformation into a concave shape is suppressed. The difference between the thermal expansion coefficient of the surface protective substrate and the thermal expansion coefficient in the other direction in the back surface protective layer is preferably 30 × 10 ⁻⁶ K ⁻¹ or less, and is preferably 20 × 10 ⁻⁶ K ⁻¹ or less. More preferably, it is 10 × 10 ⁻⁶ K ⁻¹ or less.

In the solar cell module 100, it is preferable that the back surface protection layer 32 includes a base material 321 and a fiber material 322 that is a low thermal expansion component, and the thermal expansion coefficient of the fiber material 322 is smaller than the thermal expansion coefficient of the base material 321. When the thermal expansion coefficient of the fiber material 322 is smaller than the thermal expansion coefficient of the base material 321, the thermal expansion coefficient in one direction and the thermal expansion coefficient in the other direction perpendicular to the one direction may be different from each other. it can. As a result, when the solar cell module 100 is cooled, it is suppressed from being deformed into a concave shape.

Although the thickness of the back surface protective layer 32 is not particularly limited, it is preferably 10% or less of the thickness of the surface protective substrate 20, more preferably 5% or less, and further preferably 3% or less. In addition, the lower limit of the thickness of the back surface protective layer 32 is preferably 0.8% of the thickness of the surface protective substrate 20. In addition, it is preferable that the thickness of the back surface protective layer 32 is 0.5 mm or less. By making the thickness of the back surface protective layer 32 in this way, it is possible to suppress the generation of internal stress in the back surface protective layer 32 and to reduce the weight of the solar cell module 100. Moreover, when the thickness of the back surface protective layer 32 is thin, the outgassing property inside a solar cell module can be improved. For example, when EVA is used as the material of the second sealing material layer 28, acetic acid may be generated due to the decomposition of EVA. However, when the back surface protective layer 32 is thin, the acetic acid is likely to diffuse to the outside.

It is preferable to provide a barrier layer on at least one of the front surface and the back surface of the back surface protective layer 32. That is, in the solar cell module 100 shown in FIG. 2, it is preferable to provide a barrier layer between the second sealing material layer 28 and the back surface protective layer 32. In the solar cell module 100 shown in FIG. 3, it is preferable to provide a barrier layer between the intermediate layer 30 and the back surface protective layer 32. Moreover, it is also preferable to provide a barrier layer on the main surface (back surface) on the negative direction side of the z-axis in the back surface protective layer 32 shown in FIGS. The barrier layer is preferably a layer that suppresses permeation of at least one of oxygen and water vapor. By providing such a barrier layer, it is possible to prevent oxygen and / or water vapor from entering from the back surface of the solar cell module 100 and to prevent deterioration of the sealing material. The barrier layer may be a film having a predetermined thickness or a thin film coating. The barrier layer can be made of the same material as the coating provided on the intermediate layers 24 and 30.

When fiber reinforced plastic of UD material is used for the back surface protection layer 32 and the thickness of the back surface protection layer 32 is reduced, the UD material is partially overlapped as necessary to reinforce a desired location. In the layer 32, it is possible to add strength to the characteristics. In addition, when overlapping UD materials, it is necessary to overlap the fibers of the UD materials in the same direction.

In addition, when the thickness of the back surface protective layer 32 is reduced, the back surface protective layer 32 can be bonded while following the shape of the second seal material layer 28, and between the second seal material layer 28 and the back surface protective layer 32. It is possible to make it difficult for air bubbles to be mixed in. For example, even if the surface protection substrate 20 has a curved shape, the back surface protection layer 32 can be bonded to the shape of the surface protection substrate 20 via the second sealing material layer 28. Therefore, the solar cell module 100 having a curved surface shape can be easily manufactured while suppressing the mixing of bubbles. At this time, if the film module is manufactured with the back surface protective layer 32, the second sealing material layer 28, and the intermediate layer 30 bonded together, the film module itself has flexibility. Bonding to 20 can be facilitated. In addition, since the back surface protective layer 32 has high followability, when a curved solar cell module 100 is manufactured by stacking the layers, for example, a local load is not easily applied to the solar cells 10. Damage to the cell 10 can be suppressed.

Furthermore, when the thickness of the back surface protective layer 32 is reduced, the second sealing material layer 28 can be quickly heated and crosslinked, so that not only the manufacturing time of the solar cell module 100 is shortened, but also the surface protective substrate 20 Thermal deformation can be suppressed.

In the solar cell module 100, the photoelectric conversion unit has one or more solar cells 10 connected by the tab wiring 12, and the fiber material 322 is oriented in the extending direction of the tab wiring 12 in the back surface protection layer 32. Is preferred. Specifically, in the case of the solar cell module 100 shown in FIG. 1, the fiber material 322 is preferably arranged along the y direction that is the extending direction of the tab wiring 12. In this case, since the back surface protection layer 32 is difficult to expand and contract along the y direction, the displacement of the tab wiring 12 is suppressed, and disconnection can be prevented.

As described above, in the solar cell module 100, the photoelectric conversion unit includes one or more solar cells 10 connected by the tab wiring 12. And the back surface protective layer 32 can be set as the structure which has at least 1 notch formed over a part or whole of the direction orthogonal to the extension direction of the tab wiring 12. FIG. As described above, the back surface protective layer 32 is preferably arranged so that the orientation direction of the fiber material 322 is the extending direction of the tab wiring 12. However, if the solar cell module 100 has a curved shape that bends along the extending direction of the tab wiring 12 in the configuration, warping and internal stress may occur in the orientation direction of the fiber material 322. Therefore, by providing a cut in the back surface protection layer 32 over a part or the whole in the direction orthogonal to the extending direction of the tab wiring 12, it is possible to suppress the occurrence of warping and internal stress.

6 and 7 show a form in which the back surface protective layer 32 is provided with cuts in the entire direction perpendicular to the extending direction of the tab wiring 12. That is, the back protective layer 32 shown in FIGS. 6 and 7 is divided into four by providing three cuts. Thus, since the back surface protective layer 32 is divided, the bending stress is cut off at the cut portion, so that generation of warpage and internal stress can be suppressed.

The shape, length, and thickness of the cut provided in the back surface protective layer 32 are not particularly limited as long as the above effects are exhibited. FIG. 8A is a form in which three cuts are provided from one side to the other side of the back surface protective layer 32, and FIG. 8B shows a cut from one side and a cut from the other side on two opposite sides. And three are alternately provided. In addition, in both FIG. 8A and FIG. 8B, the other side has not been cut. In both FIG. 8A and FIG. 8B, a cut is provided in a part of the back surface protective layer 32 in a direction orthogonal to the extending direction of the tab wiring 12. That is, unlike the embodiment shown in FIGS. 6 and 7, the back surface protective layer 32 is not completely divided but integrated. 8A and 8B, since the stress for bending is cut off at the cut portion, the occurrence of warpage and internal stress can be suppressed. In addition, in the back surface protective layer 32, a cut may be provided in a broken line shape.

The solar cell module 100 has one or more solar cells 10 whose photoelectric conversion portions are connected by tab wirings 12, and has a curved surface shape in which the light receiving surface side of the surface protection substrate 20 is convex, and the tab wirings 12 are curved surfaces. It can be set as the structure bent along. In the solar cell module 100, the back surface protective layer 32 has a thermal expansion coefficient in one direction smaller than that of the surface protective substrate 20, and the back surface protective layer 32 is perpendicular to the one direction thermal expansion coefficient. The thermal expansion coefficients in other directions are different from each other. Therefore, even if it is a case where the light-receiving surface side of the solar cell module 100 becomes convex, it becomes possible to suppress that the solar cell module 100 deform | transforms into a concave shape.

[Solar Cell Module of Second Embodiment]
Next, the solar cell module according to the second embodiment will be described in detail based on the drawings. In addition, the same code | symbol is attached | subjected to the same structure as the solar cell module of 1st embodiment, and the overlapping description is abbreviate | omitted.

FIG. 9 is a plan view showing a solar cell module 100A according to the second embodiment. FIG. 10A is a schematic diagram showing a cross section of the solar cell module taken along line XA-XA in FIG. 9, and FIG. 10B is a diagram of the solar cell module taken along line XB-XB in FIG. It is the schematic which shows a cross section. In FIG. 10A and FIG. 10B, the tab wiring 12 and the connection wiring 14 are omitted.

As shown in FIG. 10, the solar cell module 100 </ b> A includes a photovoltaic cell 10, a photoelectric conversion unit having a tab wiring 12 and a connection wiring 14, a surface protection substrate 20, and a first sealing material, as in the first embodiment. The layer 26, the second sealing material layer 28, and the back surface protective layer 32 are provided. Therefore, in the solar cell module 100A, in order from the light receiving surface side, the surface protection substrate 20, the first sealing material layer 26, the photoelectric conversion unit (solar cell 10, tab wiring 12, connection wiring 14), and second The sealing material layer 28 and the back surface protective layer 32 are laminated.

The same photoelectric conversion part, surface protective substrate 20, first sealing material layer 26 and second sealing material layer 28 as those in the first embodiment can be used. Moreover, the back surface protective layer 32 can use the fiber reinforced plastic which has a base material (matrix resin) and the fiber material which is provided in the inside of a base material and is a low thermal expansion component. As the fiber reinforced plastic, a UD (UniDirection) material in which fiber materials are arranged in one direction or a cloth material in which fiber materials are alternately oriented vertically and horizontally can be used. In addition, the base material and fiber material which comprise the back surface protective layer 32 can use the same thing as 1st embodiment.

When manufacturing a solar cell module, first, the surface protection substrate 20, the first sealing material layer 26, the photoelectric conversion unit, the second sealing material layer 28, and the back surface protection layer 32 are arranged in this order. By laminating, a laminate is obtained. Next, each layer is bonded by pressurizing the laminate with heating to 100 ° C. or higher using a mold. At this time, when the area of the first sealing material layer 26 and the second sealing material layer 28 and the area of the back surface protective layer 32 are substantially equal, when the laminate is pressed while heating, the sealing material is heated by heat. The resin may melt and leak from between the front surface protection substrate 20 and the back surface protection layer 32. When the resin of the sealing material leaks from the laminate, the mold is contaminated, which may reduce productivity.

Therefore, in the solar cell module 100A, when the photoelectric conversion unit is viewed in plan, the area of the back surface protection layer 32 is smaller than the area of the surface protection substrate 20, and the area of the first sealing material layer 26 and the second sealing material The area of the layer 28 is preferably larger. The back surface protection layer 32 is directly bonded to the surface protection substrate 20 so as to cover the end portion 26 a of the first sealing material layer 26 and the end portion 28 a of the second sealing material layer 28 at the periphery of the surface protection substrate 20. It is preferable. That is, as shown in FIGS. 10A and 10B, both the end portion 26 a of the first sealing material layer 26 and the end portion 28 a of the second sealing material layer 28 are covered with the back surface protective layer 32. It is preferable that The back surface protection layer 32 covers the end portion 26a of the first sealing material layer 26 and the end portion 28a of the second sealing material layer 28 over the entire circumference of the solar cell module 100A, and the back surface of the front surface protection substrate 20 with respect to the back surface. It is preferable that the joint portion of the protective layer 32 is formed in an annular shape. In this case, the first sealing material layer 26 and the second sealing material layer 28 are entirely wrapped by the front surface protection substrate 20 and the back surface protection layer 32. In addition, the junction part of the surface protection board | substrate 20 and the back surface protection layer 32 may be formed using an adhesive agent, and may be formed by welding of the back surface protection layer 32. FIG.

If the end portion 26a of the first sealing material layer 26 and the end portion 28a of the second sealing material layer 28 are exposed to the outside, the first sealing material layer 26 and the second sealing material layer 28 are heated. When tackiness is exhibited, it is assumed that the manufacturing equipment, the module itself, or the mold is soiled. In addition, the sealing material constituting the first sealing material layer 26 and the second sealing material layer 28 is sealed to protrude outward from between the front surface protection substrate 20 and the rear surface protection layer 32 so as not to interfere with the mold or the like. It is difficult to control the amount of the stop material. For this reason, the protruding shape of the sealing material is not stable, and the appearance of the solar cell module may be deteriorated. Moreover, when it designs so that the 1st sealing material layer 26 and the 2nd sealing material layer 28 may not protrude, we are anxious also about the mounting amount of the photovoltaic cell 10 reducing.

On the other hand, if the back surface protection layer 32 covers the end portion 26a of the first sealing material layer 26 and the end portion 28a of the second sealing material layer 28 as in this embodiment, such a problem is caused. Occurrence can be prevented. Furthermore, since air and moisture hardly act on the first sealing material layer 26 and the second sealing material layer 28, it is possible to suppress deterioration of the first sealing material layer 26 and the second sealing material layer 28. it can.

Thus, in the solar cell module 100A, when the photoelectric conversion unit is viewed in plan, the area of the back surface protection layer 32 is smaller than the area of the surface protection substrate 20, and the area of the first sealing material layer 26 and the second sealing layer It is larger than the area of the stopping material layer 28. The back surface protection layer 32 is directly bonded to the surface protection substrate 20 so as to cover the end portion 26 a of the first sealing material layer 26 and the end portion 28 a of the second sealing material layer 28 at the periphery of the surface protection substrate 20. ing. Thereby, since leakage of resin from between the front surface protection substrate 20 and the back surface protection layer 32 can be suppressed and contamination of the mold can be prevented, the productivity of the solar cell module 100A can be increased.

As described above, the solar cell module 100A includes the surface protection substrate 20, the first sealing material layer 26, the photoelectric conversion unit, the second sealing material layer 28, and the back surface protection layer 32. Yes. However, in the solar cell module 100A, the gel-like polymer layer 22 may be interposed between the surface protective substrate 20 and the first sealing material layer 26 as in the first embodiment. Further, the solar cell module 100A includes an intermediate layer 24 between at least one of the gel-like polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. , 30 may be further included.

As described above, the solar cell module 100A is formed by laminating the surface protective substrate 20, the first sealing material layer 26, the photoelectric conversion unit, the second sealing material layer 28, and the back surface protective layer 32. It can be obtained by applying pressure while heating. In addition, when an excess part exists in the back surface protective layer 32, after manufacturing the solar cell module 100A, the part may be cut and removed.

[Solar Cell Module of Third Embodiment]
Next, the solar cell module according to the third embodiment will be described in detail based on the drawings. In addition, the same code | symbol is attached | subjected to the same structure as the solar cell module of 1st and 2nd embodiment, and the overlapping description is abbreviate | omitted.

FIG. 11 is a plan view showing a solar cell module 100B according to the third embodiment. FIG. 12 is a cross-sectional view showing a part of the solar cell module 100B along the line XII-XII in FIG. Similar to the first embodiment, the solar cell module 100 </ b> B includes a photoelectric conversion unit having a plurality of solar cells 10, a plurality of tab wires 12, and a plurality of connection wires 14. Moreover, the solar cell module 100 </ b> B includes a surface protection substrate 20, a first sealing material layer 26, a second sealing material layer 28, and a back surface protection layer 32 in addition to the photoelectric conversion unit. In addition, the upper side of FIG. 12 corresponds to the light receiving surface (front surface) side, and the lower side corresponds to the back surface side. Therefore, in the solar cell module 100B, the surface protection substrate 20, the first sealing material layer 26, the photoelectric conversion unit, the second sealing material layer 28, and the back surface protection layer 32 are stacked in order from the light receiving surface side. Has been.

(Surface protection substrate)
The surface protection substrate 20 is a substrate that is located on the sunlight receiving side of the solar cell module 100B and is made of a resin material having translucency. As a resin material which comprises the surface protection board | substrate 20, the same thing as what was demonstrated in 1st embodiment can be used.

Similar to the first embodiment, the thickness of the surface protection substrate 20 is preferably 2 mm to 6 mm, and more preferably 3 mm to 5 mm. The tensile elastic modulus of the surface protective substrate 20 is preferably 1.0 GPa to 10.0 GPa, and more preferably 2.3 GPa to 2.5 GPa. The total light transmittance of the surface protective substrate 20 is preferably 80% or more, and more preferably 90 to 100%. The thermal expansion coefficient (linear expansion coefficient) of the surface protective substrate 20 is preferably 40 to 110 (× 10 ⁻⁶ K ⁻¹ ).

The surface protection substrate 20 is preferably convex toward the light receiving side. FIG. 13A is a schematic diagram showing a cross section of the solar cell module taken along line XIIIA-XIIIA in FIG. 11, and FIG. 13B is a diagram of the solar cell module taken along line XIIIB-XIIIB in FIG. It is the schematic which shows a cross section. In FIGS. 13A and 13B, the tab wiring 12 and the connection wiring 14 are omitted. As shown in FIGS. 13A and 13B, the surface protection substrate 20 is curved so as to be generally convex toward the light receiving side (the positive direction side of the z-axis). preferable. That is, it is preferable that the surface protection substrate 20 is curved so as to be convex toward the light receiving side along the direction of the tab wiring 12 (y direction). Further, the surface protection substrate 20 is preferably curved so as to be convex toward the light receiving side along a direction (x direction) perpendicular to the direction of the tab wiring 12. Thereby, even when the solar cell module 100B is cooled and the surface protection substrate 20 contracts along both the x direction and the y direction, the acting force that the surface protection substrate 20 deforms is dispersed, and the solar cell module 100B is concave. Can be prevented from being deformed.

(First sealing material layer, second sealing material layer)
The first sealing material layer 26 and the second sealing material layer 28 seal the solar battery cell 10. The first sealing material layer 26 is disposed on the negative direction side (lower side) of the z-axis of the surface protection substrate 20, and the second sealing material layer 28 is the positive direction side of the back surface protection layer 32 on the z-axis. (Upper side).

As the first sealing material layer 26, as in the first embodiment, for example, a gel having a tensile modulus of 0.001 MPa to 1 MPa and a loss coefficient of 0.1 to 0.52 can be used. . As the second sealing material layer 28, for example, a thermoplastic resin such as EVA (ethylene-vinyl acetate copolymer), PVB (polyvinyl butyral), polyimide, or the like can be used as in the first embodiment. . As the second sealing material layer 28, a thermosetting resin may be used.

The first sealing material layer 26 and the second sealing material layer 28 may be formed of the same material. Specifically, the first sealing material layer 26 and the second sealing material layer 28 are made of gel having a tensile modulus of 0.001 MPa to 1 MPa and a loss coefficient of 0.1 to 0.52. Also good. The first sealing material layer 26 and the second sealing material layer 28 may use thermoplastic resins such as EVA, PVB, and polyimide. However, as in the first embodiment, in the solar cell module 100 </ b> B, the tensile elastic modulus of the second sealing material layer 28 is preferably larger than the tensile elastic modulus of the first sealing material layer 26.

The first sealing material layer 26 has a light transmitting property and is formed of a rectangular sheet material having a size smaller than that of the surface protection substrate 20 in the xy plane. The second sealing material layer 28 also has translucency, and is formed of a rectangular sheet material having a size smaller than that of the surface protection substrate 20 in the xy plane.

(Back protection layer)
In order to ensure sufficient strength, the back surface protective layer 32 is preferably made of a fiber reinforced plastic having a base material (matrix resin) and a fiber material that is provided inside the base material and is a low thermal expansion component. . As the fiber reinforced plastic, a UD (UniDirection) material in which fiber materials are arranged in one direction or a cloth material in which fiber materials are alternately oriented vertically and horizontally can be used. In addition, when using UD material as the back surface protective layer 32, since the UD material is difficult to expand and contract in the fiber direction, the solar cell 10 is damaged or the tab wiring 12 is cut by adjusting the direction in which the UD material is arranged. Can be suppressed. In addition, the base material and fiber material which comprise the back surface protective layer 32 can use the same thing as 1st embodiment.

The back surface protective layer 32 is preferably convex toward the light receiving side, like the surface protective substrate 20. As shown in FIGS. 13A and 13B, the back surface protective layer 32 is curved so as to be generally convex toward the light receiving side (the positive direction side of the z-axis). preferable. That is, the back surface protection layer 32 is preferably curved so as to be convex toward the light receiving side along the direction of the tab wiring 12 (y direction). The back surface protective layer 32 is preferably curved so as to be convex toward the light receiving side along a direction (x direction) perpendicular to the direction of the tab wiring 12.

Although the thickness of the back surface protective layer 32 is not particularly limited, it is preferably 10% or less, more preferably 5% or less, and more preferably 3% or less of the thickness of the surface protection substrate 20 as in the first embodiment. More preferably it is. In addition, the lower limit of the thickness of the back surface protective layer 32 is preferably 0.8% of the thickness of the surface protective substrate 20. In addition, it is preferable that the thickness of the back surface protective layer 32 is 0.5 mm or less.

Here, in the solar cell module 100 </ b> B, when the solar battery cell 10 is viewed in plan, the end portion 26 a of the first sealing material layer 26 and the second sealing material layer 28 are located inside the end portion 20 a of the surface protection substrate 20. The end portion 28a and the end portion 32a of the back surface protective layer 32 are located. Specifically, as shown in FIGS. 13A and 13B, the end portion 26 a of the first sealing material layer 26, the end portion 28 a of the second sealing material layer 28, and the back surface protective layer 32 are formed. The end portion 32a is located on the inner side than the end portion 20a of the surface protection substrate 20, that is, on the solar cell 10 side. Thereby, an extending portion 20 b is formed on the outer edge of the surface protection substrate 20.

The extending portion 20b formed on the surface protection substrate 20 is formed by extending outward from a joint portion (an end portion 32a of the back surface protection layer 32) with the back surface protection layer 32 in the convex surface protection substrate 20. Has been. And the extension part 20b inclines toward the downward direction (the negative direction side of az axis) from the back surface protective layer 32 in the thickness direction (z direction) of the solar cell module 100B. Further, in the solar cell module 100 </ b> B, the extending portion 20 b is formed over the entire outer edge of the surface protection substrate 20.

Here, when manufacturing the solar cell module 100B, first, the surface protection substrate 20, the first sealing material layer 26, the solar cell 10 that is the photoelectric conversion unit, the tab wiring and the connection wiring, and the second A laminated body is obtained by laminating the sealing material layer 28 and the back surface protective layer 32 in this order. Subsequently, each layer is adhere | attached by pressurizing heating a laminated body to 100 degreeC or more. However, as described above, since the surface protective substrate 20 is made of a transparent resin, the surface protective substrate 20 contracts greatly when cooled to room temperature after heating. At this time, since the surface protection substrate 20 and the back surface protection layer 32 are different in material and / or thickness, the surface protection substrate 20 and the back surface protection layer 32 have a difference in shrinkage. In the present embodiment, since the front surface protection substrate 20 is thicker than the back surface protection layer 32, the front surface protection substrate 20 contracts more than the back surface protection layer 32. At this time, the surface protection substrate 20 contracts toward the apex direction of the convex surface protection substrate 20 as indicated by an arrow A in FIG.

However, in this embodiment, the extending portion 20 b is provided on the outer edge of the surface protection substrate 20. Since the extending portion 20b serves as a frame for holding the outer edge of the surface protective substrate 20, even if the surface protective substrate 20 contracts toward the apex direction, the surface protective substrate 20 warps in a concave shape. Can be suppressed. Further, as shown in FIGS. 13A and 13B, when the extending portion 20b is inclined downward (in the negative z-axis direction) from the back surface protective layer 32 in the thickness direction. The shrinkage force vector tends to be inclined toward the back surface protective layer 32 side. As a result, the entire solar cell module 100B can be maintained in a convex shape without being deformed into a concave shape.

Thus, in the solar cell module 100B, the extending portion 20b is provided on the outer edge of the surface protection substrate 20. Therefore, even if the surface protection substrate 20 is greatly contracted in the cooling process at the time of manufacture, the extended portion 20b serves as a frame for holding the outer edge of the surface protection substrate 20, so that the entire solar cell module 100B is deformed into a concave shape. Can be suppressed. Further, even when the solar cell module 100B is used in an environment where the high temperature state and the low temperature state are repeated, the solar cell module 100B is deformed into a concave shape at the time of use by providing the extending portion 20b on the outer edge of the surface protection substrate 20. Can be prevented.

The length L of the extending portion 20b provided on the outer edge of the surface protective substrate 20 is not particularly limited as long as the entire solar cell module 100B can be prevented from being deformed into a concave shape. However, in the horizontal direction (x direction and y direction), the length L between the end portion 20a of the surface protective substrate 20 and the end portion 32a of the back surface protective layer 32 (the length L of the extending portion 20b) is 1 cm. It is preferably ˜10 cm, more preferably 3 cm to 5 cm. Thereby, since the extension part 20b efficiently holds the outer edge of the surface protection substrate 20, even if the surface protection substrate 20 contracts toward the apex direction of the convex surface protection substrate 20, the surface protection substrate 20 It can suppress that it warps in a concave shape.

In the solar cell module 100B, the extended portion 20b of the surface protection substrate 20 may be provided with a convex rib 20c as shown in FIG. The rib 20c is formed so as to protrude downward (on the negative side of the z axis) from the end 20a of the surface protection substrate 20 in the thickness direction (z direction) of the solar cell module 100B. By providing such a rib 20c, the bending rigidity of the entire solar cell module 100B can be increased, and warping can be further suppressed. The rib 20c is preferably formed on at least a part of the outer edge of the surface protective substrate 20, and more preferably formed over the entire outer edge of the surface protective substrate 20.

The thickness of the rib 20c is preferably equal to the thickness of the surface protection substrate 20 from the viewpoint of productivity. Specifically, the thickness of the rib 20c is preferably 2 mm to 6 mm, and more preferably 3 mm to 5 mm. Further, the height H of the rib 20c is preferably 2 mm to 50 mm, and more preferably 5 mm to 10 mm, from the viewpoint of improving the attachment to a frame member described later.

As described above, each end of the first sealing material layer 26, the second sealing material layer 28, and the back surface protection layer 32 is positioned inside the end portion 20 a of the surface protection substrate 20. It is preferable that the extending portion 20b formed in the above is formed over the entire outer edge of the surface protection substrate. Thereby, since the extension part 20b provided in the whole outer edge of the surface protection board | substrate 20 hold | maintains the outer edge of the surface protection board | substrate 20, it becomes possible to suppress that the whole solar cell module 100B deform | transforms into a concave shape.

In addition, when the photoelectric conversion part is viewed in plan, the shape of the surface protection substrate 20 is preferably a substantially rectangular shape having a long side and a short side shorter than the long side. And it forms in the surface protection board | substrate 20 because each edge part of the 1st sealing material layer 26, the 2nd sealing material layer 28, and the back surface protection layer 32 is located inside the edge part 20a of the surface protection board | substrate 20. The extended portion 20b is preferably formed on the entire long side. That is, when the solar cell module 100B is viewed in a plan view, the extension portion 20b may be formed only on the entire long side or only on the entire short side when it is substantially square. However, it is preferable that the extending portion 20 b is formed on the entire long side of the surface protective substrate 20. Even in this case, since the extending portion 20b plays a role of a frame that holds the outer edge of the surface protection substrate 20, it is possible to suppress the entire solar cell module 100B from being deformed into a concave shape.

The outer shape of the solar cell module 100B is preferably substantially rectangular when viewed from above, and can be, for example, rectangular, square, or trapezoidal. Moreover, the solar cell module 100B may be provided with roundness at the corners. Therefore, the shape of the solar cell module 100B does not need to be an accurate quadrangle when viewed in plan.

In the solar cell module 100B, the linear expansion coefficient of the back surface protection layer 32 is preferably smaller than the linear expansion coefficient of the surface protection substrate 20. When the linear expansion coefficient of the back surface protective layer 32 is smaller than that of the front surface protective substrate 20, the back surface protective layer 32 has a smaller thermal expansion than the front surface protective substrate 20. Therefore, even when the back surface protective layer 32 is heated at the time of manufacture, the thermal expansion of the back surface protective layer 32 is suppressed, so that the shape of the back surface protective layer 32 is stabilized, and the solar cell 10, the tab wiring 12, and the connection wiring 14. Breakage can be suppressed. Moreover, since the thermal expansion of the back surface protective layer 32 is suppressed, it is possible to suppress disconnection of the tab wiring 12 and the connection wiring 14 due to thermal shock. In addition, the linear expansion coefficient of the back surface protective layer 32 can be adjusted with the addition amount and orientation of the fiber material which is a low thermal expansion component.

(Gel polymer layer)
As described above, the solar cell module 100B includes the surface protective substrate 20, the first sealing material layer 26, the solar battery cell 10, the second sealing material layer 28, and the back surface protective layer 32. . However, in the solar cell module, as shown in FIG. 15, the gel polymer layer 22 may be interposed between the surface protective substrate 20 and the first sealing material layer 26 as in the first embodiment. Good. The gel polymer layer 22 has flexibility, and follows the expansion and contraction when the surface protection substrate 20 expands and contracts. Therefore, the stress due to the expansion and contraction of the surface protection substrate 20 can be prevented from being transmitted to the solar battery cell 10.

(Middle layer)
The solar cell module 100B includes intermediate layers 24, 30 between at least one of the gel-like polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. It is preferable to further have. Moreover, it is preferable that the intermediate layers 24 and 30 are layers whose tensile elastic modulus is larger than any of the first sealing material layer 26 and the second sealing material layer 28. An intermediate layer having a relatively large tensile elastic modulus is provided between at least one of the gel-like polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. By providing, impact resistance can be improved.

In FIG. 16, the intermediate layers 24 and 30 are provided both between the gel polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. Is shown. From the viewpoint of improving the strength, it is preferable to provide two intermediate layers 24 and 30 as shown in FIG. The intermediate layers 24 and 30 can be the same as those described in the first embodiment.

Thus, the solar cell module 100B is provided on the photoelectric conversion unit including the plurality of solar cells 10 and the light receiving side where light enters the solar cells 10, and has a light-transmitting first sealing material. Layer 26. The solar cell module is further provided on the light receiving side with respect to the first sealing material layer 26, is made of a translucent resin material, and is further convex toward the light receiving side, A second sealing material layer provided on the side opposite to the light receiving side of the battery cell. The solar cell module 100B further includes a back surface protective layer 32 provided on the second sealing material layer 28 on the side opposite to the solar cells 10. When the photoelectric conversion unit is viewed in plan, the end portions of the first sealing material layer 26, the second sealing material layer 28, and the back surface protection layer 32 are located inside the end portion 20 a of the surface protection substrate 20. . Therefore, even if the surface protection substrate 20 is greatly contracted in the cooling process at the time of manufacture, the extended portion 20b serves as a frame for holding the outer edge of the surface protection substrate 20, and the entire solar cell module 100B is deformed into a concave shape. This can be suppressed. Moreover, even if the solar cell module 100B is used in an environment in which a high temperature state and a low temperature state are repeated, the extended portion 20b prevents the solar cell module 100B from being deformed into a concave shape during use. Is possible.

A frame member (not shown) may be attached to the outer edge of the solar cell module 100B. The frame member protects the end 20a of the surface protection substrate 20 in the solar cell module 100B and is used when the solar cell module 100B is installed on a roof or the like.

Further, in the solar cell module 100B, by providing the extended portion 20b on the surface protective substrate 20, the surface protective substrate 20 and a frame member such as a moving body to be described later can be joined via the extended portion 20b. it can. Therefore, the extension part 20b provided in the surface protection substrate 20 can function as a connection part with another member.

[Solar Cell Module of Fourth Embodiment]
Next, the solar cell module according to the fourth embodiment will be described in detail based on the drawings. In addition, the same code | symbol is attached | subjected to the same structure as the solar cell module of 1st thru | or 3rd embodiment, and the overlapping description is abbreviate | omitted.

FIG. 17 is a plan view showing a solar cell module 100C according to the fourth embodiment. As in the third embodiment, the solar cell module 100C includes the photovoltaic cell 10, the photoelectric conversion part having the tab wiring 12 and the connection wiring 14, the surface protection substrate 20, the first sealing material layer 26, and the second sealing. A material layer 28 and a back surface protective layer 32 are provided. Therefore, in the solar cell module 100C, in order from the light receiving surface side, the surface protection substrate 20, the first sealing material layer 26, the photoelectric conversion unit (solar cell 10, tab wiring 12, connection wiring 14), and second The sealing material layer 28 and the back surface protective layer 32 are laminated.

(Surface protection substrate)
Similar to the third embodiment, the surface protective substrate 20 is a substrate that is located on the sunlight receiving side of the solar cell module 100C and is made of a resin material having translucency. And like 3rd embodiment, it is preferable that the surface protection board | substrate 20 is convex toward the light-receiving side.

18A is a schematic view showing a cross section of the solar cell module taken along line XVIIIA-XVIIIA in FIG. 17, and FIG. 18B is a diagram of the solar cell module taken along line XVIIIB-XVIIIB in FIG. It is the schematic which shows a cross section. In FIGS. 18A and 18B, the tab wiring 12 and the connection wiring 14 are omitted. As shown in FIGS. 18A and 18B, the surface protection substrate 20 is curved so as to be generally convex toward the light receiving side (the positive direction side of the z-axis). preferable. That is, the surface protection substrate 20 is preferably curved so as to be convex toward the light receiving side along the extending direction (y direction) of the tab wiring 12. Further, the surface protection substrate 20 is preferably curved so as to be convex toward the light receiving side along the direction (x direction) perpendicular to the extending direction of the tab wiring 12. Thereby, even when the solar cell module 100C is cooled and the surface protection substrate 20 contracts along both the x direction and the y direction, the acting force that the surface protection substrate 20 deforms is dispersed, and the solar cell module 100C has a concave shape. Can be prevented from being deformed.

(First sealing material layer, second sealing material layer)
The 1st sealing material layer 26 and the 2nd sealing material layer 28 seal the photovoltaic cell 10 similarly to 3rd embodiment. The first sealing material layer 26 is disposed on the negative direction side (lower side) of the z-axis of the surface protection substrate 20, and the second sealing material layer 28 is the positive direction side of the back surface protection layer 32 on the z-axis. (Upper side).

(Back protection layer)
In the present embodiment, as in the third embodiment, a back surface protective layer 32 as a back sheet is provided to protect the back surface side of the solar cell module 100C. Similarly to the surface protection substrate 20, the back surface protection layer 32 is preferably convex toward the light receiving side. As shown in FIGS. 18A and 18B, the back surface protection layer 32 is curved so as to be generally convex toward the light receiving side (the positive direction side of the z-axis). preferable. That is, the back surface protective layer 32 is preferably curved so as to be convex toward the light receiving side along the extending direction (y direction) of the tab wiring 12. Further, the back surface protective layer 32 is preferably curved so as to be convex toward the light receiving side along a direction (x direction) perpendicular to the extending direction of the tab wiring 12. In addition, the back surface protective layer 32 can use the same thing as 3rd embodiment.

In the solar cell module 100C, when the solar battery cell 10 is viewed in plan, the end portion 26a of the first sealing material layer 26 and the end portions of the second sealing material layer 28 are located inside the end portion 20a of the surface protection substrate 20. 28a and the end portion 32a of the back surface protective layer 32 are located. Specifically, as shown in FIGS. 18A and 18B, the end portion 26 a of the first sealing material layer 26, the end portion 28 a of the second sealing material layer 28, and the back surface protective layer 32 are formed. The end portion 32a is located inside the end portion 20a of the surface protection substrate 20, that is, on the solar cell 10 side. Thereby, an extending portion 20 b is formed on the outer edge of the surface protection substrate 20.

The extending portion 20b formed on the surface protection substrate 20 is formed by extending outward from a joint portion (an end portion 32a of the back surface protection layer 32) with the back surface protection layer 32 in the surface protection substrate 20. . And the extension part 20b inclines toward the downward direction (negative direction side of az axis) from the back surface protective layer 32 in the thickness direction (z direction) of the solar cell module 100C. In the solar cell module 100 </ b> C, the extending portion 20 b is formed over the entire outer edge of the surface protection substrate 20.

Here, the extension formed on the surface protection substrate by the end portions of the first sealing material layer, the second sealing material layer, and the back surface protection layer being located inside the end portion 20a of the surface protection substrate 20. It is preferable that a reinforcing member 21 having a bending strength greater than that of the surface protection substrate is disposed in the existing portion 20b. Specifically, as shown in FIG. 17, the reinforcing member 21 is disposed over the entire extending portion 20 b of the surface protection substrate 20, and has a substantially rectangular frame when viewed in plan. Further, as shown in FIG. 18, a protruding portion 20 d that protrudes downward from the back surface protective layer 32 is formed on the extending portion 20 b of the surface protective substrate 20. The protrusion 20d forms an end 20a and an inner surface 20e parallel to the z-axis, and a flat surface 20f parallel to the xy plane. And the reinforcement member 21 is embed | buried under the inside of the protrusion part 20d, and the cross section of the reinforcement member 21 is a substantially rectangular shape.

As shown in FIGS. 17 and 18, the reinforcing member 21 is disposed outside the solar battery cell 10, that is, on the end 20 a side of the surface protection substrate 20 in a plan view. Further, when viewed in plan, the reinforcing member 21 is located on the outer side of the bonding portion (the end portion 32a of the back surface protective layer 32) with the back surface protective layer 32 in the front surface protective substrate 20, that is, on the end portion 20a side of the front surface protective substrate 20. It is preferable that they are arranged.

The reinforcing member 21 preferably has a higher bending strength than the surface protection substrate 20. That is, the material constituting the reinforcing member 21 preferably has a higher bending strength than the material constituting the surface protection substrate 20. By providing such a highly rigid reinforcing member 21 in the extending portion 20b of the surface protection substrate 20, it is possible to suppress warping caused by a temperature change of the solar cell module 100C, as will be described later. In the present specification, the bending strength of the surface protective substrate 20 and the reinforcing member 21 can be determined according to JIS K7171: 2016 (Plastics—How to determine bending characteristics).

As the material constituting the reinforcing member 21, it is preferable to use a material capable of increasing the bending strength as compared with the surface protection substrate 20. For example, at least one of resin and metal can be used as the material constituting the reinforcing member 21. Although resin which comprises the reinforcement member 21 is not specifically limited, For example, the same resin as the resin which comprises the above-mentioned back surface protective layer 32 can be used. Although the metal which comprises the reinforcement member 21 is not specifically limited, For example, aluminum or aluminum alloy can be used. As a material constituting the reinforcing member 21, it is also preferable to use fiber reinforced plastic. As the fiber reinforced plastic constituting the reinforcing member 21, the same fiber reinforced plastic as that constituting the back surface protective layer 32 described above can be used.

Here, when manufacturing the solar cell module 100C, first, the surface protection substrate 20, the first sealing material layer 26, the solar cell 10 as the photoelectric conversion unit, the tab wiring and the connection wiring, and the second A laminated body is obtained by laminating the sealing material layer 28 and the back surface protective layer 32 in this order. Subsequently, each layer is adhere | attached by pressurizing heating a laminated body to 100 degreeC or more. However, as described above, since the surface protective substrate 20 is made of a transparent resin, the surface protective substrate 20 contracts greatly when cooled to room temperature after heating. At this time, since the surface protection substrate 20 and the back surface protection layer 32 are different in material and / or thickness, the surface protection substrate 20 and the back surface protection layer 32 have a difference in shrinkage. In the present embodiment, since the front surface protection substrate 20 is thicker than the back surface protection layer 32, the front surface protection substrate 20 contracts more than the back surface protection layer 32. At this time, the surface protective substrate 20 contracts toward the apex direction of the convex surface protective substrate 20 as indicated by an arrow A in FIG.

However, in this embodiment, the extending portion 20b is provided on the outer edge of the surface protection substrate 20, and the reinforcing member 21 having a high bending strength is disposed on the extending portion 20b. Therefore, since the reinforcing member 21 serves as a frame for holding the outer edge of the surface protection substrate 20, even if the surface protection substrate 20 contracts toward the apex direction, the surface protection substrate 20 warps in a concave shape. Can be suppressed. Furthermore, as shown in FIGS. 18A and 18B, when the reinforcing member 21 protrudes downward (in the negative direction of the z axis) from the back surface protective layer 32 in the thickness direction, The shrinkage force vector tends to tilt toward the back surface protective layer 32 side. As a result, the entire solar cell module 100C can be maintained in a convex shape without being deformed into a concave shape.

Thus, in the solar cell module 100C, the reinforcing member 21 is provided on the outer edge of the surface protection substrate 20. Therefore, even if the surface protection substrate 20 is greatly contracted in the cooling process at the time of manufacture, since the reinforcing member 21 serves as a frame for holding the outer edge of the surface protection substrate 20, the entire solar cell module 100C is deformed into a concave shape. This can be suppressed. Further, even when the solar cell module 100C is used in an environment where the high temperature state and the low temperature state are repeated, by providing the reinforcing member 21 on the outer edge of the surface protection substrate 20, the solar cell module 100C is deformed into a concave shape at the time of use. Can be prevented.

In addition, in the thickness direction (z direction) of the surface protection substrate 20, the thickness of the extended portion 20 b in the state where the reinforcing member 21 is embedded may be larger than the thickness of the portion other than the extended portion 20 b in the surface protective substrate 20. preferable. Even in this case, since the extended portion 20b serves as a frame for holding the outer edge of the surface protection substrate 20, even if the surface protection substrate 20 contracts toward the apex direction, the surface protection substrate 20 warps in a concave shape. Can be suppressed.

As described above, in the solar cell module 100C, the reinforcing member 21 is disposed on the extending portion 20b of the surface protection substrate 20. And as shown in FIG. 18, it is preferable that the reinforcement member 21 is embed | buried under the extension part 20b of the surface protection board | substrate 20. As shown in FIG. That is, it is preferable that the entire surface of the reinforcing member 21 is covered with the resin constituting the surface protection substrate 20 and fixed inside the extending portion 20b. Since the reinforcing member 21 is embedded in the extending portion 20b, when the reinforcing member 21 is made of metal, deterioration of the reinforcing member 21 such as rust is suppressed, and deformation of the solar cell module 100C is prevented over a long period of time. Is possible. In addition, since the reinforcing member 21 is embedded in the extending portion 20b, it is possible to suppress the reinforcing member 21 from dropping from the surface protection substrate 20 due to poor adhesion. Furthermore, since the reinforcing member 21 is embedded, the number of parts to be assembled at the time of manufacturing the solar cell module 100C is reduced, and thus the manufacturing cost can be suppressed.

As described above, in the solar cell module 100C, the reinforcing member 21 is disposed on at least a part of the extending portion 20b of the surface protection substrate 20. However, it is preferable that the reinforcing member 21 is disposed over the entire extending portion 20 b of the surface protection substrate 20. Thereby, since the reinforcement member 21 provided in the whole extension part 20b hold | maintains the outer edge of the surface protection board | substrate 20 firmly, it becomes possible to suppress that the solar cell module 100C whole deform | transforms into a concave shape.

In addition, when the photoelectric conversion part is viewed in plan, the shape of the surface protection substrate 20 is preferably a substantially rectangular shape having a long side and a short side shorter than the long side. And it is preferable that the reinforcement member 21 is arrange | positioned at the whole long side. That is, when the solar cell module 100C is substantially rectangular when viewed in plan, the reinforcing member 21 may be disposed only on the entire long side or may be disposed only on the entire short side. However, the reinforcing member 21 is preferably disposed over the entire long side of the surface protection substrate 20. Even in this case, since the reinforcing member 21 serves as a frame for holding the outer edge of the surface protection substrate 20, it is possible to suppress the entire solar cell module 100C from being deformed into a concave shape. Further, by disposing the reinforcing member 21 only on the long side of the surface protection substrate 20, it is possible to suppress the deformation to the concave shape with the minimum amount of the reinforcing member 21, and to further reduce the weight and cost. .

The outer shape of the solar cell module 100C is preferably substantially rectangular when viewed from above, and can be, for example, rectangular, square, or trapezoidal. Further, the solar cell module 100C may be provided with rounded corners. Therefore, the shape of the solar cell module 100C does not need to be an accurate quadrangle when viewed in plan.

A frame member may be attached to the outer edge of the surface protection substrate 20 in the solar cell module 100C. The frame member protects the outer edge of the surface protection substrate 20 in the solar cell module, and is used when the solar cell module is installed on a roof or the like. Moreover, in the solar cell module, by providing the extended portion 20b on the surface protective substrate 20, the surface protective substrate 20 and a frame member such as a moving body to be described later can be joined via the extended portion 20b. . Therefore, the extension part 20b provided in the surface protection substrate 20 can function as a connection part with another member.

More specifically, as shown in FIGS. 19 and 20, the solar cell module 100D includes a frame member 40 having a substantially rectangular shape when viewed from above. The frame member 40 is attached to the extending portion 20b of the surface protection substrate 20, and surrounds the end 20a and the flat surface 20f of the surface protection substrate 20. The frame member 40 is attached to the extending portion 20b using attachment means such as an adhesive.

20A and 20B, the frame member 40 has an L-shaped cross section. That is, the frame member 40 includes a side covering portion 40a that extends in the z direction and covers the end portion 20a of the extending portion 20b, and a positioning portion 40b that protrudes in the x direction or the y direction.

As a material constituting the frame member 40, for example, a thermoplastic resin such as polycarbonate, vinyl chloride resin, polyester, or ABS resin, a thermosetting resin such as phenol resin or polyurethane, or a rubber material such as nitrile rubber is used. it can. Moreover, as a material which comprises the frame member 40, metal materials, such as aluminum and steel materials, can also be used.

The adhesive layer 41 as an attachment means is interposed between the end portion 20a of the surface protection substrate 20 and the side cover portion 40a, and between the flat surface 20f of the surface protection substrate 20 and the positioning portion 40b, thereby protecting the surface. The substrate 20 and the frame member 40 are fixed. The adhesive layer 41 can include, for example, at least one selected from the group consisting of an epoxy resin, an acrylic resin, a urethane resin, and a silicone resin. Moreover, it is preferable that the adhesive layer 41 is comprised with resin made into paste form, for example by mixing a solid component with the epoxy resin which added the hardening | curing agent. However, as the adhesive layer 41, any resin material that is disposed between the extending portion 20b of the surface protection substrate 20 and the frame member 40 and can bond the extending portion 20b and the frame member 40 can be used. Anything can be used.

As in the solar cell module 100D, the frame member 40 can be installed on the outer periphery of the surface protection substrate 20 by utilizing the extending portion 20b of the surface protection substrate 20. Further, by interposing an attachment means such as an adhesive layer 41 between the extended portion 20b of the surface protection substrate 20 and the frame member 40, the sealing property on the back surface side of the back surface protection layer 32 in the solar cell module is enhanced. , Foreign matter can be prevented from entering the back side.

In the solar cell module 100C, as shown in FIG. 18, the reinforcing member 21 is disposed in the extending portion 20b of the surface protection substrate 20, and the reinforcing member 21 is embedded in the extending portion 20b. . However, the present embodiment is not limited to such an aspect, and the solar cell module 100C can be prevented from warping in a concave shape by disposing the reinforcing member 21 in the extending portion 20b of the surface protection substrate 20. . Therefore, the reinforcing member 21 may be disposed on the extended portion 20 b of the surface protection substrate 20 in a state exposed to the outside of the surface protection substrate 20.

As shown in FIG. 21, the extending portion 20 b of the surface protection substrate 20 extends outward from a joint portion (an end portion 32 a of the back surface protection layer 32) with the back surface protection layer 32 in the surface protection substrate 20. Is formed. And the reinforcement member 21 may be fixed to the back surface on the opposite side to the light-receiving surface (front surface) in the extension part 20b. Further, the reinforcing member 21 may be provided so as to protrude downward (in the negative z-axis direction) from the back surface protective layer 32 in the thickness direction (z direction) of the solar cell module 100C. Furthermore, as shown in FIG. 22, the reinforcing member 21 may be fixed to the light receiving surface (surface) in the extending portion 20b. Further, the reinforcing member 21 may be provided so as to protrude toward the upper side of the surface protection substrate 20 (the positive side of the z axis) in the thickness direction (z direction) of the solar cell module 100C.

As shown in FIGS. 21 and 22, the reinforcing member 21 is disposed on the extending portion 20 b of the surface protection substrate 20, and further on the outer edge side than the joint portion with the back surface protection layer 32 in the surface protection substrate 20. It is preferable that the reinforcing member 21 is in contact. Thus, by providing the reinforcing member 21 on the outer edge side with respect to the back surface protection layer 32 functioning as the installation surface of the solar battery cell 10, the outer edge of the surface protection substrate 20 is firmly held and warped in a concave shape. Can be suppressed.

Here, the reinforcing member 21 may be provided on the back surface of the front surface protection substrate 20 so as to straddle the joint portion (the end portion 32a of the back surface protection layer 32) with the back surface protection layer 32 in the front surface protection substrate 20. Specifically, as shown in FIG. 23, a part of the reinforcing member 21 is located on the outer edge side of the joint part, and the other part of the reinforcing member 21 is inside the joint part, that is, a solar battery cell. It may be located on the 10 side. At this time, the reinforcing member 21 is preferably plate-shaped. Thus, even when the reinforcing member 21 is provided on the back surface of the front surface protection substrate 20 so as to straddle the joint between the front surface protection substrate 20 and the back surface protection layer 32, the extending portion 20 b of the front surface protection substrate 20. It becomes possible to suppress warping in a concave shape.

As described above, the solar cell module 100 </ b> C includes the surface protection substrate 20, the first sealing material layer 26, the solar battery cell 10, the second sealing material layer 28, and the back surface protection layer 32. . However, in the solar cell module 100C, the gel-like polymer layer 22 may be interposed between the surface protective substrate 20 and the first sealing material layer 26 as in the third embodiment. Further, the solar cell module 100C includes the intermediate layer 24 between at least one of the gel-like polymer layer 22 and the first sealing material layer 26 and between the second sealing material layer 28 and the back surface protective layer 32. , 30 may be further included.

As described above, the solar cell modules 100C and 100D are provided on the light receiving side on which light is incident on the solar cells 10 and the first sealing material layer 26 having translucency. Is provided. The solar cell modules 100 </ b> C and 100 </ b> D are further provided on the light receiving side with respect to the first sealing material layer 26, and the light receiving side in the solar cell 10 and the surface protection substrate 20 made of a translucent resin material And a second sealing material layer 28 provided on the opposite side. The solar cell modules 100C and 100D further include a back surface protective layer 32 provided on the opposite side of the second sealing material layer 28 from the solar cells 10. A reinforcing member 21 having a bending strength greater than that of the surface protective substrate 20 is disposed on the extended portion 20 b of the surface protective substrate 20. Therefore, even if the surface protection substrate 20 is greatly contracted in the cooling process at the time of manufacture, the reinforcing member 21 provided on the extending portion 20b serves as a frame for holding the outer edge of the surface protection substrate 20, and the entire solar cell module. Can be prevented from being deformed into a concave shape. Moreover, even if the solar cell module 100C is used in an environment in which a high temperature state and a low temperature state are repeated, the solar cell module 100C is deformed into a concave shape during use because the reinforcing member 21 is provided in the extending portion 20b. It becomes possible to prevent this. Further, by using a lightweight material for the reinforcing member 21, it is possible to suppress the warpage of the solar cell module 100C while reducing the weight of the surface protection substrate 20.

In addition, as described above, the solar cell modules 100C and 100D include the solar cell 10, the surface protection substrate 20, the first sealing material layer 26, the second sealing material layer 28, and the back surface protection layer 32 as a whole on the light receiving side. It is preferable that it is convex toward the surface. However, the solar cell module of the present embodiment is not limited to such a shape, and the solar cell 10, the surface protection substrate 20, the first sealing material layer 26, the second sealing material layer 28, and the back surface protection layer 32 are provided. It may be flat as a whole. That is, the solar battery cell 10, the surface protection substrate 20, the first sealing material layer 26, the second sealing material layer 28, and the back surface protection layer 32 may be parallel to the xy plane as a whole.

[Moving object]
The moving body of the present embodiment is a moving body that includes the above-described solar cell module. Examples of the moving body include vehicles such as automobiles, trains, ships, and the like. When the solar cell module of the present embodiment is mounted on an automobile, it is preferably installed on the upper surface portion of the automobile body such as a bonnet or a roof panel. In any of the moving bodies, a current obtained by generating power using the solar cell module of the present embodiment is supplied to an electric device such as a fan or a motor, and is used for driving and controlling the electric device.

Hereinafter, although the solar cell module of the first embodiment will be described in more detail with reference to Example 1, the solar cell module of the first embodiment is not limited thereto.

[Example 1-1]
As shown in FIG. 24, in order from the light receiving surface side, the surface protective substrate 20, the gel polymer layer 22, the first sealing material layer 26, the solar battery cell 10, the second sealing material layer 28, and the back surface protective layer. About the solar cell module which laminated | stacked 32, it evaluated by simulation.

The surface protective substrate 20 was a polycarbonate plate and had a thickness of 2 mm. The gel-like polymer layer 22 was made of silicone gel and had a thickness of 1 mm. For the first sealing material layer 26 and the second sealing material layer 28, ethylene-vinyl acetate copolymer (EVA) was used, and each thickness was 0.6 mm. Solar cell 10 had a thickness of 0.12 mm. The back surface protective layer 32 is made of carbon fiber reinforced plastic (UD material) in which carbon fibers are oriented in one direction and has a thickness of 0.2 mm.

Here, regarding the back surface protective layer 32 used, Table 1 shows the thermal expansion coefficient and the tensile elastic modulus in the fiber direction B of the carbon fiber and the direction C perpendicular to the fiber direction B shown in FIG. As shown in Table 1, since the thermal expansion coefficient in the fiber direction B of the back surface protective layer 32 is smaller than the vertical direction C, the back surface protective layer 32 is a layer that hardly stretches along the fiber direction B. Further, since a polycarbonate plate is used as the surface protection substrate 20, the thermal expansion coefficient in the fiber direction of the back surface protection layer 32 is smaller than the thermal expansion coefficient of the surface protection substrate 20.

The two-dimensional displacement when such a solar cell module was cooled was analyzed by simulation. As analysis software, Femtet (registered trademark) manufactured by Murata Software Co., Ltd. was used. The analysis conditions were set as follows.
・ 2D model 1/2 symmetry ・ Solver: Stress analysis, static analysis ・ Model size: 280mm
・ Mesh shape: Tetra secondary element ・ Boundary condition: Not fixed ・ Heat load: 25 ℃ to -40 ℃

The simulation results are shown in FIGS. 25 (b), 25 (c), and 25 (d). FIG. 25 (b) shows the result of obtaining the displacement along the fiber direction B when the solar cell module is cooled. FIG. 25 (c) shows the result of obtaining the displacement when the solar cell module is cooled along the direction C perpendicular to the fiber direction B. In addition, in FIG.25 (b) and FIG.25 (c), the displacement of the right end at the time of fixing the left end of a solar cell module is calculated | required. In FIGS. 25B and 25C, the solar cell module at 25 ° C. is indicated by a solid line, and the solar cell module at −40 ° C. is indicated by a two-dot chain line. The graph of FIG. 25D shows the relationship between the amount of displacement in the vertical direction (z direction) and the temperature at the right end of the solar cell module.

As shown in FIG. 25 (b), when the solar cell module is cooled, it can be seen that in the fiber direction B, the right end of the solar cell module is displaced upward. Further, as shown in FIG. 25 (d), it is understood that the right end of the solar cell module is warped upward by about 5 mm when cooled from 25 ° C. to −40 ° C. On the other hand, as shown in FIG. 25C, when the solar cell module is cooled, it can be seen that the right end of the solar cell module is displaced downward in the direction C perpendicular to the fiber direction B. Further, as shown in FIG. 25 (d), it can be seen that when the solar cell module is cooled from 25 ° C. to −40 ° C., the right end of the solar cell module is warped downward by about 2.5 mm.

That is, in the fiber direction B, the surface protection substrate 20 is contracted, but the back surface protection layer 32 is difficult to contract, and thus the solar cell module is warped upward as a whole. On the other hand, in the direction C perpendicular to the fiber direction B, the back surface protective layer 32 contracts when the surface protective substrate 20 contracts, so that the solar cell module is warped downward as a whole. .

[Example 1-2]
Three-dimensional evaluation was performed by simulation using the same solar cell module as in Example 1-1. Specifically, the three-dimensional displacement when the solar cell module was cooled was analyzed by simulation. The same analysis software as in Example 1-1 was used. The analysis conditions were set as follows.
・ 3D model 1/4 symmetry ・ Stress: Static analysis ・ Model size: 1m × 1m
-Model shape: Convex shape curved in two axes of R6000-Mesh shape: Tetra secondary element-Boundary condition: Unfixed-Thermal load: 25 ° C to -40 ° C

In the solar cell module of this example, as shown in FIG. 26A, a UD material in which carbon fibers are oriented in one direction inside the matrix resin was used as the back surface protective layer. And in FIG.26 (b) and FIG.26 (c), the result of the simulation of such a solar cell module is shown. In addition, in FIG.26 (b), the displacement of the right end at the time of fixing the left end of a solar cell module is calculated | required. In FIG. 26B, the solar cell module at 25 ° C. is indicated by a solid line, and the solar cell module at −40 ° C. is indicated by a two-dot chain line. The graph in FIG. 26C shows the relationship between the amount of displacement in the vertical direction (z direction) and the temperature at the right end of the solar cell module.

As shown in FIG. 26 (b), it is understood that when the solar cell module is cooled, the right end of the solar cell module is displaced downward. Further, as shown in FIG. 26 (c), when cooled from 25 ° C. to −40 ° C., the right end of the solar cell module is warped by 7 mm or more downward. That is, in the solar cell module of Example 1-2, when the front surface protection substrate 20 contracts, the solar cell module warps downward as a whole because the back surface protective layer 32 also contracts in the direction perpendicular to the carbon fibers. It turns out that it will be in a state.

[Comparative Example 1]
Three-dimensional evaluation was performed by simulation in the same manner as in Example 1-2, except that the back surface protective layer 32 in the solar cell module of Example 1-2 was changed from the UD material to the cloth material. Specifically, in the solar cell module of this example, as shown in FIG. 27 (a), as the back surface protective layer, a cloth material in which carbon fibers are alternately oriented vertically and horizontally inside the matrix resin is used. did. Note that the back surface protective layer made of a cloth material has a thermal expansion coefficient of 1 × 10 ⁻⁶ K ⁻¹ and a tensile elastic modulus of 120 GPa in both the x and y directions. Further, since a polycarbonate plate is used as the surface protection substrate 20, the thermal expansion coefficients in the x direction and the y direction in the back surface protection layer are smaller than the thermal expansion coefficient of the surface protection substrate 20. In this example, analysis software and analysis conditions were the same as those in Example 1-2.

27 (b) and 27 (c) show the results of simulation of such a solar cell module. In addition, in FIG.27 (b), the displacement of the right end at the time of fixing the left end of a solar cell module is calculated | required. In FIG. 27B, the solar cell module at 25 ° C. is indicated by a solid line, and the solar cell module at −40 ° C. is indicated by a two-dot chain line. The graph of FIG. 27C shows the relationship between the amount of displacement in the vertical direction (z direction) and the temperature at the right end of the solar cell module.

As shown in FIG. 27 (b), when the solar cell module is cooled, it can be seen that the right end of the solar cell module is displaced upward. In addition, as shown in FIG. 27 (c), when cooled from 25 ° C. to −40 ° C., the right end of the solar cell module is warped upward by about 10 mm or more. That is, in the solar cell module of Comparative Example 1, the front surface protection substrate 20 contracts, but the back surface protection layer hardly contracts in both the x direction and the y direction, so that the solar cell module may be warped upward as a whole. I understand.

[Example 1-3]
Using the same solar cell module as in Example 1-1, the followability of the gel polymer layer was evaluated by simulation. Specifically, the displacement of the gel polymer layer when the solar cell module was cooled was analyzed by simulation. The analysis software was the same as in Example 1-1, and the analysis conditions were the same as in Example 1-1.

FIG. 28 (a) shows the result of obtaining the displacement when the solar cell module 100 is cooled along the fiber direction B of FIG. 25 (a). FIG. 28B shows an enlarged right end of FIG. 28A when the solar cell module 100 is cooled and deformed. In FIGS. 28A and 28B, the solar cell module at 25 ° C. is represented by a solid line, and the solar cell module at −40 ° C. is represented by a two-dot chain line.

As shown in FIG. 28A, when the solar cell module 100 is cooled, in the fiber direction B, the front surface protection substrate 20 is contracted, but the back surface protection layer 32 is difficult to contract. As shown in FIG. And as shown in FIG.28 (b), even when the surface protection board | substrate 20 shrink | contracts, since the lower gel-like polymer layer 22 has a small tensile elasticity modulus, it turns out that it can follow the shrinkage | contraction of the surface protection board | substrate 20. FIG. Therefore, it can be understood that stress due to expansion and contraction of the surface protection substrate 20 can be prevented from being transmitted to the photoelectric conversion unit, and further, warpage (deformation) of the entire solar cell module can be suppressed.

Hereinafter, the solar cell module of the third embodiment will be described in more detail with reference to Example 2, but the solar cell module of the third embodiment is not limited thereto.

The solar cell module in which the surface protective substrate, the first sealing material layer, the solar battery cell, the second sealing material layer, and the back surface protective layer were laminated in order from the light receiving surface side was evaluated by simulation. At this time, a polycarbonate plate was used as the surface protection substrate, and the thickness was 3 mm. For the first sealing material layer and the second sealing material layer, ethylene-vinyl acetate copolymer (EVA) was used, and the thickness was 0.6 mm. The solar battery cell had a thickness of 0.12 mm. The back protective layer used was a polyethylene terephthalate sheet and the thickness was 0.1 mm.

And in the solar cell module of Example 2, the extending portion having a length L of 50 mm was formed over the entire outer edge of the surface protective substrate. On the other hand, in the solar cell module of Comparative Example 2, no extending portion was formed.

Next, the three-dimensional displacement when the solar cell modules of Example 2 and Comparative Example 2 were cooled was analyzed by simulation. As analysis software, Femtet (registered trademark) manufactured by Murata Software Co., Ltd. was used. The analysis conditions were set as follows.
・ 3D model 1/4 symmetry ・ Stress: Static analysis ・ Model size: 1.1 m × 1.1 m (see FIG. 29)
Model shape: convex shape curved in two axes, R3000 and R5000 (see FIG. 29)
・ Mesh shape: Tetra secondary element ・ Boundary condition: Not fixed ・ Heat load: 25 ℃ to -40 ℃

FIG. 29 schematically shows the solar cell modules of Example 2 and Comparative Example 2. From FIG. 29, the solar cell modules of Example 2 and Comparative Example 2 have a convex shape curved in two axes, and are convex toward the light receiving side.

FIG. 30 shows the results of simulation in the solar cell modules of Example 2 and Comparative Example 2. FIG. 30 is a ¼-symmetrical diagram showing the displacement of the end when the center of the solar cell module is fixed. In FIG. 30, the solar cell module at 25 ° C. is indicated by a solid line, and the solar cell module at −40 ° C. is indicated by a two-dot chain line.

As shown in FIG. 30, when the solar cell module is cooled, it can be seen that the end of the solar cell module is displaced upward. That is, in the solar cell modules of Example 2 and Comparative Example 2, a polycarbonate plate having a thickness of 3 mm is used as the surface protective substrate, and a polyethylene terephthalate plate having a thickness of 0.1 mm is used as the back surface protective layer. Therefore, it can be seen that the surface protective substrate having a large thickness contracts greatly as the temperature decreases, and the solar cell module warps upward as a whole.

As a result of the simulation, when the solar cell module of Example 2 was cooled from 25 ° C. to −40 ° C., the end portion of the solar cell module warped upward by 50 mm. On the other hand, in the solar cell module of Comparative Example 2, when cooled from 25 ° C. to −40 ° C., the end of the solar cell module warped upward by 145 mm.

As described above, by providing the extending portion on the outer edge of the surface protective substrate, the amount of upward displacement of the solar cell module can be suppressed even when the surface protective substrate is greatly contracted. Therefore, it turns out that it can suppress that the whole solar cell module deform | transforms into a concave shape.

As described above, the contents of the present embodiment have been described according to the examples. However, the present embodiment is not limited to these descriptions, and it is obvious to those skilled in the art that various modifications and improvements are possible. is there.

The entire contents of Japanese Patent Application No. 2018-045106 (filing date: March 13, 2018) are incorporated herein by reference.

According to the present disclosure, a solar cell module capable of suppressing concave warpage can be obtained by a simple method.

DESCRIPTION OF SYMBOLS 10 Solar cell 12 Tab wiring 20 Surface protection board 20a End part of surface protection board 20b Extension part 21 Reinforcement member 22 Gel-like polymer layer 24 Intermediate | middle layer 26 1st sealing material layer 26a End of 1st sealing material layer Part 28 Second sealing material layer 28a End part of second sealing material layer 30 Intermediate layer 32 Back surface protective layer 32a End part of back surface protective layer 100, 100A, 100B, 100C, 100D Solar cell module 321 Base material 322 Fiber material

Claims (20)

1. In order from the light receiving surface side, a resin surface protective substrate, a gel polymer layer, a first sealing material layer, a photoelectric conversion part, a second sealing material layer, and a low thermal expansion component oriented in one direction. A back surface protective layer comprising:
   The tensile elastic modulus of the gel polymer layer is smaller than any tensile elastic modulus of the surface protective substrate, the first sealing material layer, and the second sealing material layer,
   The back protective layer has a thermal expansion coefficient in one direction smaller than that of the surface protective substrate,
   The solar cell module in which the thermal expansion coefficient in the one direction and the thermal expansion coefficient in the other direction perpendicular to the one direction are different from each other in the back surface protective layer.
2. 2. The solar cell module according to claim 1, wherein a difference between a thermal expansion coefficient of the surface protective substrate and a thermal expansion coefficient in the other direction of the back surface protective layer is 30 × 10 ⁻⁶ K ⁻¹ or less.
3. The back surface protective layer has a base material and a fiber material that is the low thermal expansion component,
   The thermal expansion coefficient of the fiber material is smaller than the thermal expansion coefficient of the base material,
   The solar cell module of Claim 1 or 2 whose thickness of the said back surface protective layer is 0.5 mm or less.
4. The photoelectric conversion unit has one or more solar cells connected by tab wiring,
   The solar cell module according to claim 3, wherein in the back surface protective layer, the fiber material is oriented in an extending direction of the tab wiring.
5. The first sealing material layer has a tensile modulus of elasticity between at least one of the gel-like polymer layer and the first sealing material layer and between the second sealing material layer and the back surface protective layer. And the solar cell module as described in any one of Claims 1 thru | or 4 which further has an intermediate | middle layer larger than any tensile elasticity modulus of a said 2nd sealing material layer.
6. The solar cell module according to claim 5, wherein a thermal expansion coefficient of the intermediate layer is smaller than a thermal expansion coefficient of either the first sealing material layer or the second sealing material layer.
7. The solar cell module according to claim 5 or 6, wherein the intermediate layer located between the second sealing material layer and the back surface protective layer has electrical insulation.
8. The photoelectric conversion unit has one or more solar cells connected by tab wiring,
   The solar cell module according to any one of claims 1 to 7, wherein the back surface protective layer has at least one cut formed in a part or the whole of a direction orthogonal to the extending direction of the tab wiring. .
9. The photoelectric conversion unit has one or more solar cells connected by tab wiring,
   The solar cell module according to any one of claims 1 to 8, wherein the light-receiving surface side of the surface protection substrate has a curved surface shape that is convex, and the tab wiring is bent along the curved surface shape.
10. The said back surface protective layer covers the edge part of the 1st sealing material layer and the edge part of the 2nd sealing material layer in the peripheral edge of the surface protection board, and is directly joined to the surface protection board. The solar cell module according to any one of 1 to 9.
11. When the photoelectric conversion unit is viewed in plan, the area of the back surface protective layer is smaller than the area of the surface protective substrate, and larger than the areas of the first sealing material layer and the second sealing material layer, The solar cell module as described in any one of Claims 1 thru | or 10.
12. When the photoelectric conversion unit is viewed in plan, the respective end portions of the first sealing material layer, the second sealing material layer, and the back surface protection layer are located inside the end portion of the surface protection substrate. The solar cell module according to claim 1.
13. An extension formed on the surface protection substrate by positioning each end of the first sealing material layer, the second sealing material layer, and the back surface protection layer inside the edge of the surface protection substrate. The solar cell module according to claim 12, wherein the existing portion is formed over the entire outer edge of the surface protection substrate.
14. When the photoelectric conversion unit is viewed in plan, the shape of the surface protection substrate is a substantially quadrilateral having a long side and a short side shorter than the long side,
    An extension formed on the surface protection substrate by positioning each end of the first sealing material layer, the second sealing material layer, and the back surface protection layer inside the edge of the surface protection substrate. The solar cell module according to claim 12, wherein the existing portion is formed over the entire long side.
15. An extension formed on the surface protection substrate by positioning each end of the first sealing material layer, the second sealing material layer, and the back surface protection layer inside the edge of the surface protection substrate. The solar cell module according to claim 12, wherein a reinforcing member having a bending strength greater than that of the surface protection substrate is disposed in the existing portion.
16. The solar cell module according to claim 15, wherein the reinforcing member is in contact with an outer edge side of a joint portion of the front surface protective substrate with the back surface protective layer.
17. The solar cell module according to claim 15 or 16, wherein the reinforcing member is embedded in an extending portion of the surface protection substrate.
18. The solar cell module according to any one of claims 15 to 17, wherein the reinforcing member is disposed over the entire extending portion of the surface protection substrate.
19. When the photoelectric conversion unit is viewed in plan, the shape of the surface protection substrate is a substantially quadrilateral having a long side and a short side shorter than the long side,
    The solar cell module according to any one of claims 15 to 18, wherein the reinforcing member is disposed over the entire long side.
20. A moving body comprising the solar cell module according to any one of claims 1 to 19.

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