JP2012094742A - Solar battery module and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin-film solar battery module, which has high strength of a surface protection layer and is lightweight and low-cost, and a method for producing the same.SOLUTION: A solar battery module is configured with lamination of a water vapor barrier film, a first adhesive filling layer and a surface protection layer on a surface side of a solar battery submodule sealed with an adhesive filling material, and lamination of a second adhesive filling layer and a backside protection layer on a back surface side of the solar battery submodule. A light absorption layer of the solar battery submodule is composed of a CIGS film. At least the surface protection layer among the surface protection film and the back surface protection layer is composed of a plastic sheet. Heat shrinkage rate of this plastic sheet is 0.04% or less.

Description

  The present invention relates to a solar cell module using CIGS for a photoelectric conversion layer and a manufacturing method thereof, and in particular, a solar cell module having a high surface protection layer strength, impact strength, light weight, and low cost, and a manufacturing method thereof. About.

  A solar cell is formed by connecting a number of solar cells in a stacked structure in which a light absorption layer of a semiconductor that generates current by light absorption is sandwiched between a lower electrode (back electrode) and an upper electrode (transparent electrode). It is configured and formed on a substrate. A solar cell having such a configuration is attracting attention as clean energy. Therefore, research on solar cells has been actively conducted, and improvements have been attempted from various viewpoints.

As an example, solar cells are weak in moisture, and when moisture enters, characteristics such as conversion efficiency deteriorate. In particular, CIS (CuInSe ₂ ) having a chalcopyrite structure composed of Ib group, IIIb group, and VIb element, CIGS (Cu (In, Ga) Se ₂ ) obtained by further dissolving Ga in CIS, and the like, absorb light. A chalcopyrite solar cell used as a layer uses a ZnO film or the like as a transparent electrode, so that the transparent electrode is altered by the ingress of moisture. As a result, the resistance value of the transparent electrode is increased, and the conversion efficiency is greatly decreased.
However, as is well known, solar cells are often installed outdoors, such as mounts, roofs or rooftops installed outdoors. Therefore, various proposals for improving the waterproofness of the solar cell module have been made (Patent Documents 1 to 7, etc.).

  In Patent Document 1, a plurality of CIS-based thin-film solar cell device portions laminated in the order of an alkali barrier layer, a metal back electrode layer, a light absorption layer, a buffer layer, and a window layer on a glass substrate are electrically connected by a conductive pattern. Semi-strengthened white plate by using an ethylene vinyl acetate (hereinafter referred to as EVA) resin film (or sheet) cross-linked by heating and causing a polymerization reaction to the connected CIS thin film solar cell circuit (or submodule) A CIS thin film solar cell module having a structure in which a cover glass made of glass or the like is attached is described.

Patent Document 2 discloses a surface protective layer, a filler layer comprising a resin layer having at least transparency, cushioning properties, heat resistance, and excellent non-degradation or non-degradability with respect to the action of heat, solar cell An element, a filler layer, and a back surface protective layer are sequentially laminated, and at least one or more of an antifouling layer, an ultraviolet shielding layer, or a weathering layer is laminated on either the layer or the interlayer. An integrated solar cell module is described.
Patent Document 2 describes that the surface protective layer or the back surface protective layer is made of a vapor deposition film in which a vapor deposition film of an inorganic oxide is provided on a base film.

Patent Document 3 describes a solar cell module including a solar cell submodule that receives sunlight and generates power and a sealing material that seals the entire solar cell submodule. This sealing material is a protective sheet that seals the solar cell sub-module and prevents moisture inflow from the outside. The light-receiving surface side sealing material that covers the light-receiving surface side of the solar cell module is opposite to the light-receiving surface. It consists of the back side sealing material which covers the surface of the side.
The light receiving surface side sealing material and the back surface side sealing material have a plane size larger than the plane size of the solar cell submodule, and can cover the entire plane of the solar cell submodule.
Moreover, the light-receiving surface side sealing material and the back surface side sealing material are made of a fluororesin, and the thickness is about 50 to 200 μm from the viewpoint of realizing durability and weight reduction during use. It is described that it is suitable.

In Patent Document 4, a transparent synthetic resin substrate, a plurality of solar cells arranged on the substrate with a light receiving surface facing the substrate and a gap portion provided on the substrate, and wiring in the gap portion on the substrate In addition, a solar battery panel is described which includes an interconnector for connecting the electrodes of solar battery cells and a synthetic resin coating that covers the back surface of the cells and joins the gaps of the substrate.
Patent Document 4 describes that a polycarbonate resin plate or a methyl methacrylate resin plate, or a laminate plate of a polycarbonate resin and a methyl methacrylate resin is used for the synthetic resin substrate.

  In Patent Document 5, in a solar cell module that seals a filler and a solar cell element by a solar cell element, a surface protective layer and a back surface protective layer for sealing the solar cell element, and spacers on both sides, heat resistance, weather resistance, moisture resistance, etc. In order to satisfy these functions, as a surface protection sheet for solar cell modules, a surface protection sheet in which a resin film such as PET film, acrylic or polycarbonate is laminated on the inner surface of a cyclic olefin copolymer film or a cyclic olefin copolymer film via an adhesive A solar cell module using is described.

Patent Document 6 discloses a solar cell surface protective sheet comprising a laminate in which a polycarbonate film layer is laminated on the vapor deposition thin film layer side of a transparent vapor deposition film layer in which at least a vapor deposition thin film layer of an inorganic oxide is laminated on a transparent film layer. A solar cell module using is described.
In patent document 6, gas barrier property is exhibited by the transparent vapor deposition film layer formed by laminating | stacking the vapor deposition thin film layer of an inorganic oxide.

  Patent Document 7 discloses a back surface protection sheet used for solar cells, the back surface protection sheet being an unstretched transparent polybutylene terephthalate film, an adhesive layer disposed on the unstretched transparent polybutylene terephthalate film, Gas barrier vapor deposition film provided with a vapor deposition layer formed by vapor-depositing an inorganic oxide on the material, using a back protective sheet for solar cells in which the gas barrier vapor deposition film is disposed on the solar cell element side, The solar cell module unitized so that the unstretched polybutylene terephthalate film layer surface of the back surface protection sheet for solar cells becomes an outer side is described.

JP 2007-123725 A JP 2001-196614 A JP 2009-194114 A Japanese Patent Laid-Open No. 10-190034 JP 2006-165434 A JP 2006-120972 A International Publication No. 2006/106844

As described above, Patent Document 1 retains impact strength and waterproofness by providing the most common white plate tempered glass as the surface protective layer. However, the commonly used glass has a thickness of 3 mm. When the thickness is 3 mm, the weight is 7.5 kg / m ² . For this reason, in Patent Document 1, it is difficult to reduce the weight.

On the other hand, in patent documents 2-7, the surface protection layer is comprised with the resin film or the resin sheet as a glass substitute material. In Patent Document 2, polyethylene, polypropylene, fluorine-based, polyolefin, acrylic, and the like are exemplified as resins having transparency, cushioning properties, heat resistance, and the like. However, in these, waterproofing required for CIGS solar cells is realized. Is not.
In patent document 3, although the light-receiving surface side sealing material and the back surface side sealing material use the fluorine-type film of 50-200 micrometers thickness, there exists a problem that mechanical strength and impact strength are weak, and also a water vapor | steam barrier film | membrane Therefore, there is also a problem that long-term reliability cannot be obtained due to lack of moisture resistance with respect to CIGS solar cells.

In Patent Document 4, the surface protective layer is made of a synthetic resin substrate and is made of a laminate of polycarbonate, methacrylate, and both. However, the entire structure does not include a water vapor barrier layer and uses a CIGS film as a light absorption layer ( Hereinafter, there is a problem that long-term reliability cannot be obtained due to lack of moisture resistance. In addition, when the module is manufactured, there is a problem in that the module is warped due to thermal contraction of the synthetic resin substrate in the vacuum laminating process.
Moreover, in patent document 5, although it is the structure which laminated | stacked resin films, such as PET, an acryl, and a polycarbonate, on the inner surface of the cyclic olefin polymer film as a surface protection sheet on the light-receiving side, the surface protection sheet is an olefin polymer film. The impact strength is weak, and a constituent material having a water vapor barrier property is required for CIGS solar cells.

  Patent Document 6 is provided with a transparent vapor deposition film layer in which an inorganic oxide vapor deposition thin film layer is laminated to exhibit gas barrier properties, and Patent Document 7 has a gas barrier vapor deposition film. In a humid environment, there is a problem that separation occurs due to the difference in thermal expansion and contraction of each member, or that some cavities are generated and moisture penetrates into the interior, resulting in significant deterioration in characteristics. .

  Here, as a characteristic required for the solar cell module having a long-term reliability of 20 to 30 years, it is a matter of course that the conversion efficiency of the solar cell itself is high, but weather resistance, heat resistance, flame retardancy, It is excellent in water resistance, moisture resistance, wind pressure resistance, yield resistance, and other characteristics. In addition, it is necessary to reduce the construction cost for installing the solar cell module and the panel itself together with lowering the price. In order to reduce the overall cost of conventional heavy-duty solar cell panels and solar cell modules that use tempered glass as the surface protective layer, it also takes costs such as reinforcement work to fix to ordinary houses or slate roofs, etc. It is desired to realize a solar cell module that is light in weight and excellent in performance.

  An object of the present invention is to eliminate the problems based on the above prior art, and to provide a thin-film solar cell module and a method for manufacturing the same, in which the strength of the surface protective layer is high and the weight is low.

  In order to achieve the above object, according to a first aspect of the present invention, a water vapor barrier film, a first adhesive filling layer and a surface protective layer are laminated on the surface side of a solar cell submodule sealed with an adhesive filler. A solar cell module in which a second adhesive filling layer and a back surface protective layer are laminated on the back surface side of the solar cell submodule, wherein the solar cell submodule has a light absorption layer as a CIGS film. Of the surface protective layer and the back surface protective layer, at least the surface protective layer is composed of a plastic sheet, and the plastic sheet has a heat shrinkage rate of 0.04% or less. The solar cell module characterized by this is provided.

In this case, the plastic sheet is made of a polycarbonate resin or an acrylic resin, and the thickness of the plastic sheet is preferably 0.5 to 2.5 mm.
Moreover, it is preferable that the intermediate sealing material for water vapor | steam invasion prevention is provided 5-30 mm inside from the peripheral part of the said back surface protective layer.
The frame member further includes a frame member provided at a peripheral portion, and the frame member includes a sealing material provided on the inner side and an outer frame material provided on the outer side, and the sealing material is made of butyl rubber or silicone resin. In addition, the outer frame material is preferably composed of an aluminum frame or a metal foil tape.
Furthermore, it is preferable that the substrate used for the solar cell submodule is aluminum, stainless steel, and a clad material of aluminum, or a clad material of aluminum and stainless steel.
Furthermore, it is preferable that the intermediate sealing material is composed of butyl rubber, polyisoprene or isoprene.
Moreover, it is preferable that the fluorine-type transparent resin film is provided on the said surface protective layer. In this case, the said fluorine-type transparent resin film is comprised by ETFE, PTFE, PFA, or PVDF, for example.

  According to a second aspect of the present invention, a water vapor barrier film, a first adhesive filling layer and a surface protective layer are laminated on the surface side of a solar cell submodule sealed with an adhesive filler, A method of manufacturing a solar cell module in which a second adhesive filling layer and a back surface protective layer are laminated on the back side of the module, wherein the solar cell submodule has a light absorption layer formed of a CIGS film Of the surface protective layer and the back surface protective layer, at least the surface protective layer is made of a plastic sheet, and the plastic sheet is preheated at a temperature of 100 to 140 ° C., and the solar cell sub On the surface side of the module, an adhesive filler, a water vapor barrier film, a first adhesive filling layer, and a heat-treated plastic sheet to be the surface protective layer And stacking and arranging a second adhesive filling layer and a back surface protective layer on the back surface side of the solar cell sub-module, and a vacuum in a state where the plurality of layers are stacked and disposed. And a step of laminating the solar cell module.

In this case, in the step of stacking and arranging, it is preferable to arrange an intermediate sealing material for preventing water vapor intrusion 5 to 30 mm inside from the peripheral edge of the back surface protective layer.
Moreover, it is preferable after the said vacuum lamination process to have the process of providing the frame member in which the sealing material was provided inside, and the outer frame material was provided in the outer side at the peripheral part of the said vacuum lamination.
The plastic sheet is made of polycarbonate resin or acrylic resin, and the thickness of the plastic sheet is preferably 0.5 to 2.5 mm.
Furthermore, it is preferable to arrange | position a fluorine-type transparent resin film on the said plastic sheet in the said process to laminate | stack and arrange | position. In this case, the said fluorine-type transparent resin film is comprised by ETFE, PTFE, PFA, or PVDF, for example.

According to the present invention, by using a plastic sheet having a thermal shrinkage rate of 0.04% or less for the surface protective layer, the mechanical strength such as wind pressure resistance, yield resistance, etc. equal to or higher than that of white sheet tempered glass, It can be impact strength. And if it is the same thickness, since a density is 2.5-g / cm < ³ > of glass and a plastic sheet is 1.1-1.2 g / cm < ³ >, mass can be made 50% or less.
In general, the thickness of the white plate tempered glass is 3 mm. Further, by reducing the thickness of the surface protective layer to 1 to 2 mm, the mass per unit area is 1.2 to 2.4 kg / m. Can be ² . In this case, the weight can be reduced to 16 to 32% of the white plate tempered glass.

  Moisture or water vapor may diffuse from the surface or end face (peripheral part) of the solar cell module and cause defects such as performance deterioration and wiring corrosion. However, a water vapor barrier film is provided on the front side and the end face (peripheral part) is provided. By providing the intermediate sealing material or the frame member, it is possible to more reliably suppress defects such as performance deterioration and wiring corrosion due to moisture or water vapor. Even if moisture enters, it is possible to prevent reaching a transparent electrode such as a solar battery cell.

As described above, according to the present invention, it is possible to realize a solar cell module that can prevent moisture from entering the solar cell module, exhibit stable performance over a long period of time, and can be used stably.
In addition, according to the manufacturing method of the solar cell module of this invention, the solar cell module which has such an outstanding characteristic can be manufactured suitably.
And according to the manufacturing method of the solar cell module of this invention, generation | occurrence | production of the curvature in the process of vacuum laminating is suppressed by heat-processing the plastic sheet which comprises a surface protective layer beforehand at the temperature of 100-140 degreeC. .

(A) is typical sectional drawing which shows the solar cell module of the 1st Embodiment of this invention, (b) is the arrangement | positioning state of each member before the vacuum lamination of the solar cell module of Fig.1 (a) It is a typical sectional view showing. It is a graph which shows the relationship between the thickness in a polycarbonate sheet, the amount of shrinkage, and the amount of curvature. It is typical sectional drawing which shows an example of the solar cell submodule used for the solar cell module of the 1st Embodiment of this invention. It is typical sectional drawing which shows the arrangement | positioning state of each member before the vacuum lamination of the solar cell module of the 2nd Embodiment of this invention. It is typical sectional drawing which shows the arrangement | positioning state of each member before the vacuum lamination of the solar cell module of the 3rd Embodiment of this invention. It is typical sectional drawing which shows the conventional solar cell module. It is typical sectional drawing which shows the other conventional solar cell module.

Hereinafter, a solar cell module and a manufacturing method thereof according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
Fig.1 (a) is typical sectional drawing which shows the solar cell module of the 1st Embodiment of this invention, (b) is each member before the vacuum lamination of the solar cell module of Fig.1 (a). It is a typical sectional view showing an arrangement state.

As shown in FIG. 1A, in the solar cell module 10, the solar cell submodule 12 is sealed with an adhesive filler 20. An intermediate sealing material 18 is provided around the adhesive filler 20. The intermediate sealing material 18 is provided at a position of a distance m from the peripheral edge α of the solar cell module 10, that is, inside the solar cell module 10.
A second adhesive filling layer 14 is provided on the back surface 12 b of the solar cell submodule 12, and a back sheet (back surface protective layer) 16 is provided below the second adhesive filling layer 14.
A water vapor barrier film 22 is provided on the surface 12 a side of the solar cell submodule 12. A first adhesive filling layer 24 is provided on the water vapor barrier film 22, and a surface protective layer 26 is provided on the first adhesive filling layer 24.
In the solar cell module 10, the second adhesive filling layer 14, the back sheet 16, the water vapor barrier film 22, the first adhesive filling layer 24, and the surface protective layer 26 are joined at the peripheral edge α.

In the solar cell module 10, as shown in FIG. 1B, an intermediate sealing material 18 is provided around the solar cell submodule 12, and an adhesive filler 20 is disposed so as to close the opening of the intermediate sealing material 18. The The second adhesive filling layer 14 and the back sheet 16 are laminated and disposed on the back surface 12 b side of the solar cell submodule 12.
On the adhesive filler 20, a water vapor barrier film 22, a first adhesive filler layer 24, and a surface protective layer 26 are laminated.
In this case, the intermediate sealing material 18 is disposed at a distance m, for example, 5 to 30 mm inside from the peripheral edge α of each member.

In a state where the respective members are stacked and arranged as shown in FIG. 1B, for example, using a vacuum laminator having an elevating means, a buffer plate, and a heating means, for example, at a temperature of 130 to 140 ° C., a vacuum / The solar cell module 10 shown in FIG. 1 (a) can be produced by vacuum lamination under conditions of a total of 15 to 30 minutes of pressing / holding.
In this embodiment, a fluorine-based transparent resin film, which will be described later, is laminated on the surface 26a of the surface protective layer 26, and in this state, vacuum lamination is performed to produce a solar cell module. it can.

  In the solar cell module 10 shown in FIG. 1A, the solar cell submodule 12 is an integrated structure of solar cells 40 that are photoelectric conversion elements, as shown in FIG. One solar cell 40 is also included in the solar cell submodule. Specific examples of the solar cell submodule 12 will be described later in detail.

  The adhesive filler 20 is for sealing the solar cell submodule 12. For example, EVA (ethylene vinyl acetate), PVB (polyvinyl butyral), PE (polyethylene), an olefin-based adhesive, or the like can be used for the adhesive filler 20. In addition to this, various kinds of materials used as sealing materials in known solar cell modules can be used. In order to improve adhesion, a primer is previously applied to a plastic sheet or an adherend, or the surface of the plastic sheet is subjected to, for example, a corona treatment in which it is exposed to a corona discharge atmosphere. Adhesion can be strengthened.

The intermediate sealing material 18 is for suppressing the penetration of moisture from the adhesive filler 20 into the solar cell submodule 12. The intermediate sealing material 18 is provided at a position of a distance m from the peripheral edge α of the solar cell module 10. This distance m is preferably 5 to 30 mm as a distance that does not reduce manufacturing variations and module efficiency. The width of the intermediate sealing material 18 is preferably 5 to 20 mm.
As the intermediate sealing material 18, for example, butyl rubber, polyisoprene, isoprene or the like exhibiting thermoplasticity is used.

  The second adhesive filling layer 14 is for adhering the back sheet 16. For example, the same adhesive filler 20 as the adhesive filler 20 can be used for the second adhesive filler layer 14. For this reason, detailed description is omitted.

The back sheet 16 protects the solar cell module 10 from the back side.
For example, the back sheet 16 has a structure in which an aluminum foil is sandwiched between resin films such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and PVF (polyvinyl fluoride). It is not particularly limited.
The back sheet 16 is not limited to a film, and a metal plate such as a galvanium steel plate, a stainless steel plate, a clad steel plate of aluminum and stainless steel, or the like can be used. In addition to this, various known solar cell modules that are used as the back sheet 16 or the support can be used. As the back sheet 16, in particular, a plastic sheet or a plastic resin honeycomb structure similar to the surface protective layer 26 described in detail later is used in order to prevent warpage of the rubber sheet and the module, not a steel plate for weight reduction. It is also possible.

The water vapor barrier film 22 is for protecting the solar cell submodule 12 from moisture. The water vapor barrier film 22 is not particularly limited, and various known water vapor barrier films can be used.
As the water vapor barrier film 22, a water vapor barrier film having a water vapor transmission rate of 1 × 10 ⁻² (g / (m ² · day)) or less is particularly preferably used. By using such a water vapor barrier film 22, it is possible to more reliably prevent the solar cell module 10 from being deteriorated by moisture over a long period of time.

A suitable example of the water vapor barrier film 22 is an inorganic compound that exhibits water vapor barrier properties (gas barrier properties) using various resin films (plastic films) such as PET films and PEN films having a thickness of about 50 to 100 μm as substrates. And a water vapor barrier film formed by forming a layer (hereinafter also referred to as an inorganic layer).
In the water vapor barrier film 22, if the required transparency can be ensured, the surface of the gas water vapor barrier film 22 has 1 layer exhibiting various functions such as an adhesion layer, a planarization layer, and an antireflection layer. More than one layer may be formed.

In the water vapor barrier film 22, the inorganic compound exhibiting the water vapor barrier property is, for example, a diamond-like compound, a metal oxide, a metal nitride, a metal carbide, a metal oxynitride, or a metal oxycarbide. The inorganic compound contains, for example, one or more metals selected from diamond-like carbon (DLC), diamond-like carbon containing silicon, Si, Al, In, Sn, Zn, Ti, Cu, Ce, or Ta. Examples thereof include oxides, nitrides, carbides, oxynitrides, and oxide carbides.
Among these, a metal oxide, nitride, or oxynitride selected from Si, Al, In, Sn, Zn, and Ti is preferable. In particular, a metal oxide, nitride, or oxynitride of Si or Al is preferable. preferable.
These inorganic layers are formed by, for example, a plasma CVD method, a sputtering method, or the like.

  As a more preferable example of the water vapor barrier film 22, various resin films such as a PET film and a PEN film are used as a substrate, and an organic compound layer (hereinafter also referred to as an organic layer) is used as a base layer. In addition, a water vapor barrier film formed by forming the above-described inorganic layer may be mentioned. According to this water vapor barrier film 22, higher water vapor barrier properties can be obtained.

In addition, as an organic compound used as an underlayer, acrylic resin, methacrylic resin, epoxy resin, polyester, methacrylic acid-maleic acid copolymer, polystyrene, transparent fluororesin, polyimide, fluorinated polyimide, polyamide, polyamideimide, polyether Examples include imide, cellulose acylate, polyurethane, polyether ketone, polycarbonate, fluorene ring-modified polycarbonate, alicyclic ring-modified polycarbonate, and fluorene ring-modified polyester. Of these, acrylic resins and methacrylic resins are particularly preferable.
Such an organic layer is formed by, for example, a coating method using a known coating means such as a roll coating method or a spray coating method, a flash vapor deposition method, or the like.

  The first adhesive filling layer 24 is for bonding the gas water vapor barrier film 22 and the surface protective layer 26. As the first adhesive filling layer 24, for example, the same one as the adhesive filling material 20 can be used. For this reason, detailed description is omitted.

When the solar cell module 10 is installed outdoors, the surface protective layer 26 may come into contact with rain, hail, hail, snow, stones, and the like. A protective material having high mechanical strength such as wind pressure resistance and drooping resistance, and high impact strength is used.
The surface protective layer 26 protects the solar cell module 10 from dirt and the like, and suppresses a decrease in the amount of incident light on the solar cell submodule 12 due to dirt and the like.

The surface protective layer 26 is composed of a plastic sheet, and has transparency, weather resistance, heat resistance, flame resistance, water resistance, moisture resistance, wind pressure resistance, yield resistance, chemical resistance, and other characteristics. It is necessary to be excellent. The surface protective layer 26 is made of, for example, polycarbonate resin, acrylic resin or methacrylic resin, or a laminate thereof. In the surface protective layer 26, there are structural deterioration due to UV light and yellowing as weather resistance, but it can be improved by mixing a UV absorber with these resins. Furthermore, an inorganic coat layer may be provided as a hard coat layer on the surface of the surface protective layer 26 in order to retain scratch resistance.
In addition, the thickness of the surface protective layer 26 (the thickness of the plastic sheet) is, for example, 0.5 to 2.5 mm, and preferably 1.0 to 2.0 mm.
If the thickness of the surface protective layer 26 is less than 0.5 mm, the solar cell submodule 12 cannot be sufficiently protected from external force applied from the outside, impact, or the like. On the other hand, when the thickness of the surface protective layer 26 exceeds 2.5 mm, the temperature distribution increases in the vertical direction during vacuum lamination, and the surface protective layer 26 may be warped. Further, it is desirable that the material is thin in view of material cost.

In addition, the plastic sheet which comprises the surface protective layer 26 is a plastic sheet which comprises the surface protective layer 26 by heat-processing a plastic sheet beforehand at 100 to 140 degreeC, Preferably it is 120 to 130 degreeC, before vacuum laminating. It is possible to suppress thermal contraction of the sheet, relieve the residual stress of the plastic sheet, and suppress warping during vacuum lamination. In this case, the heat treatment time is, for example, 0.5 to 10 hours, preferably 1 to 3 hours.
Further, the heat treatment suppresses the generation of wrinkles and the like in the surface protective layer 26 due to the thermal contraction that occurs during the vacuum lamination, and the decrease in the amount of light incident on the solar cell submodule 12 can also be suppressed. .

As shown in Table 1 below, the present applicant examined the influence of the amount of warpage of the plastic sheet (surface protective layer 26) by the heat treatment while changing the lamination temperature. The sample size was a 20 cm square shape, the amount of warpage in two orthogonal directions with the center of the sample as the origin was examined, and the larger value was taken as the amount of warpage.
The amount of warpage was the distance from the surface plate to the farthest place in each direction by placing the heat-treated sample on the surface plate.

  Experimental Example 1 shown in the following Table 1 is a polycarbonate sheet having a thickness of 1.0 mm and is not heat-treated. Experimental Example 2 is a polycarbonate sheet having a thickness of 1.0 mm, and heat-treated at 130 ° C. for 3 hours. Experimental Example 3 is a laminated sheet of polycarbonate and PET having a thickness of 1.0 mm and heat-treated at 130 ° C. for 1 hour. Experimental Example 4 is a polycarbonate sheet having a thickness of 1.5 mm and not heat-treated. Experimental Example 5 is a polycarbonate sheet having a thickness of 1.5 mm and heat-treated at 130 ° C. for 3 hours. Experimental Example 6 is a laminated sheet of polycarbonate and PET having a thickness of 1.5 mm and heat-treated at 130 ° C. for 3 hours. Experimental Example 7 is a PET sheet having a thickness of 1.5 mm, and heat-treated at 130 ° C. for 3 hours. Experimental Example 8 is a laminated sheet of polycarbonate and PET having a thickness of 1.5 mm and heat-treated at 140 ° C. for 1 hour.

As shown in Table 1 below, Experimental Examples 1 and 4 that are not heat-treated have a larger amount of warpage than Experimental Examples 2, 3, and 5 to 8 that are heat-treated regardless of the thickness. Thus, it is obvious that the warpage during vacuum lamination can be suppressed by heat treatment.
In addition, since the glass transition point is exceeded when temperature is 145 degreeC or more, it has also confirmed that a wrinkle generate | occur | produces in a plastic sheet.

  Further, by using the same plastic sheet as the surface protective layer 26 for the back sheet 16, the warpage caused by the surface protective layer 26 can be offset, thereby suppressing the warpage that occurs during vacuum lamination. Further, as the first adhesive filling layer 24 provided under the plastic sheet constituting the surface protective layer 26, a hot melt type adhesive resin film having a low melt adhesion temperature, for example, a urethane type adhesive resin film, Warpage that occurs during vacuum lamination can be suppressed.

  In addition, the present applicant examined the relationship between the shrinkage amount and the warpage amount of the plastic sheet constituting the surface protective layer 26. When the plastic sheet is manufactured by an extrusion method, residual strain is generated in the drawing direction (RD direction). When vacuum lamination is performed, warping occurs because residual strain of the plastic sheet is released. On the other hand, the heat shrinkage rate can be reduced to 0.04% or less by previously heat-treating the plastic sheet. As described above, it is possible to suppress the warpage of the solar cell module by reducing the thermal shrinkage rate of the plastic sheet, that is, the shrinkage amount. The warpage amount d of the plastic sheet is approximated by the Stoney's formula shown in the following formula 1.

Note that in the above equation 1, l (el) panel length / 2, R is the radius of curvature, _{E s} is Young's modulus of the plastic sheet, [nu _s is Poisson's ratio of the plastic sheet, _{t F} is the thickness underlayer, _{t s} plastic The thickness of the sheet, ε is the shrinkage, σ is the internal stress, and E is the Young's modulus.

As described above, warpage in the vacuum laminating process can be suppressed by reducing the thermal shrinkage rate, that is, the shrinkage amount.
For the polycarbonate sheet, the amount of warpage was calculated with respect to l (el) = 10 cm while changing the thickness. The result is shown in FIG. As shown in FIG. 2, it can be seen that the amount of warpage of the polycarbonate sheet is suppressed by reducing the shrinkage.
In the present invention, the warp is suppressed by setting the thermal shrinkage rate of the plastic sheet constituting the surface protective layer 26 to 0.04% or less. When the thermal shrinkage rate exceeds 0.04%, for example, the amount of warpage increases as shown in FIG. 2 such that the amount of shrinkage is 0.07%. In particular, when the thickness is small, the amount of warpage increases rapidly. For this reason, in the present invention, the thermal contraction rate of the plastic sheet is set to 0.04% or less.

Further, in order to enhance the heat resistance and flame retardancy of the solar cell module 10, ETFE (tetrafluoroethylene), PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyethylene) is formed on the surface 26 a of the surface protective layer 26. Fluorine-based transparent resin films such as PVDF (polyvinylidene fluoride) may be provided. In this case, for example, the fluorinated transparent resin film is provided via an adhesive filling layer. Further, a fluorine-based transparent resin film may be formed on the plastic sheet constituting the surface protective layer 26 by a coextrusion method or the like.
In addition, the fluororesin film has a thickness of 20 to 100 μm, for example.

Next, the solar cell submodule 12 of this embodiment will be described in detail with reference to FIG.
As shown in FIG. 3, the solar cell submodule 12 has a plurality of solar cells 40 including a lower electrode 32, a light absorption layer 34, a buffer layer 36, and an upper electrode 38 connected in series on a substrate 50. It will be. This solar cell (photoelectric conversion element) 40 uses a CIGS semiconductor compound as the light absorption layer 34. The solar cell submodule 12 has a first conductive member 42 and a second conductive member 44.

In the solar cell submodule 12, the substrate 50 is a flexible substrate including a base material 52, an Al (aluminum) layer 54, and an insulating layer 56.
The base material 52 and the Al layer 54 are integrally formed. The insulating layer 56 is an anodic oxide film having an Al porous structure formed by anodizing the surface of the Al layer 54. The clad substrate in which the base material 52 and the Al layer 54 are laminated and integrated is referred to as a metal substrate 55.

In the solar cell submodule 12 of the present invention, mild steel, heat resistant steel, or stainless steel is used as the (metal) base material 52 constituting the substrate 50.
The thickness of the substrate 52 is not particularly limited, but is preferably 10 to 1000 μm in consideration of the balance between flexibility and strength (rigidity), handling properties, and the like.

The Al layer 54 is a layer mainly composed of Al, and various types of Al and Al alloys can be used. In particular, Al having a purity of 99% by mass or more with few impurities is preferable. As purity, for example, 99.99 mass% Al, 99.96 mass% Al, 99.9 mass% Al, 99.85 mass% Al, 99.7 mass% Al, 99.5 mass% Al, etc. are preferable. .
Moreover, even if it is not high purity Al, industrial Al can also be utilized. Use of industrial Al is advantageous in terms of cost. However, it is important that Si is not precipitated in Al in terms of the insulating property of the insulating layer 56.

The thickness of the Al layer 54 is not particularly limited and can be appropriately selected. In the state where the solar cell submodule 12 is obtained, the thickness of the Al layer 54 is preferably 0.1 μm or more and less than the thickness of the base material 52. .
The Al layer 54 is formed by pretreatment of the Al surface, formation of the insulating layer 56 by anodic oxidation, generation of an intermetallic compound on the surface of the Al layer 54 and the base material 52 when the light absorption layer 34 is formed, The thickness decreases. Therefore, the thickness at the time of forming an Al layer 54 to be described later is Al between the base material 52 and the insulating layer 56 in a state where the solar cell submodule 12 is formed in consideration of thickness reduction due to these. It is important that the thickness be such that layer 54 remains. For this reason, the thickness of the Al layer 54 is required to be 10 to 50 μm in order to form an insulating layer by anodic oxidation.

An insulating layer 56 is formed on the Al layer 54 (on the side opposite to the substrate 52). The insulating layer 56 is an Al anodic oxide film formed by anodizing the surface of the Al layer 54.
Here, various anodic oxide films formed by anodizing Al can be used for the insulating layer 56, but a porous anodic oxide film is preferable. This anodic oxide film is an alumina oxide film having pores of several tens of nanometers. Since the Young's modulus of the film is low, the film is highly resistant to bending and cracking caused by a difference in thermal expansion at high temperatures.

  The thickness of the insulating layer 56 is preferably 2 μm or more, and more preferably 5 μm or more. When the thickness of the insulating layer 56 is excessively large, it is not preferable because flexibility is lowered and cost and time required for forming the insulating layer 56 are required. Actually, the thickness of the insulating layer 56 is 50 μm or less, preferably 30 μm or less at maximum. For this reason, the preferable thickness of the insulating layer 56 is 2 to 50 μm.

Although the solar cell module 10 of this embodiment is a rigid type, a flexible substrate is used for the solar cell submodule 12, and for example, an insulation having a plurality of pores by anodization on a metal substrate 55 having a thickness of 50 to 200 μm. A layer 56 (insulating oxide film) is formed, and high insulation is ensured.
The substrate 50 used in the solar cell submodule 12 of this embodiment may be subjected to a specific sealing process after the Al layer 54 is anodized to form the insulating layer 56. The manufacturing process may include various processes other than the essential processes. For example, a degreasing process for removing the adhering rolling oil, a desmutting process for dissolving the smut on the surface of the Al layer 54, a roughening process for roughening the surface of the Al layer 54, and an anode on the surface of the Al layer 54 The substrate 50 is preferably subjected to an anodizing process for forming an oxide film and a sealing process for sealing the micropores of the anodized film.

In addition, the board | substrate 50 becomes flexible as the board | substrate 50 whole by making all the base material 52, Al layer 54, and the insulating layer 56 have flexibility, ie, a flexible thing. Thereby, for example, an alkali supply layer, a lower electrode, a light absorption layer, an upper electrode, and the like described later can be formed on the insulating layer 56 side of the substrate 50 by a roll-to-roll method.
In the present invention, a solar cell structure may be produced by continuously forming a plurality of layers from one roll unwinding to winding, or roll unwinding, film forming, winding The solar cell structure may be formed by performing the taking step a plurality of times. Further, as will be described later, a solar cell in which a plurality of solar cells 40 are electrically connected in series by adding a scribing process for separating and accumulating elements between the respective film forming processes to the production by the roll-to-roll method. A battery submodule can be fabricated.

In the present invention, the Al layer 54 and the insulating layer 56 are not limited to be formed only on one surface of the base material 52, and the substrate in which the Al layer 54 and the insulating layer 56 are formed on both surfaces of the base material 52 is used. Alternatively, the Al layer may be a single layer, that is, an Al substrate provided with an insulating layer composed of the above-described anodized film.
As the metal substrate, a material in which a metal oxide film formed on the surface of the metal substrate by anodic oxidation is an insulator can be used. Therefore, in addition to aluminum (Al), specifically, zirconium (Zr), titanium (Ti), magnesium (Mg), copper (Cu), niobium (Nb), tantalum (Ta), etc., and their Alloys can be used. Aluminum is most preferable from the viewpoint of cost and characteristics required for the solar cell module.
Further, a so-called clad material may be used in which the metal layer is formed by rolling or hot dipping on a steel plate such as mild steel or stainless steel in order to improve heat resistance.

Here, an alkali supply layer 58 (an alkali metal supply source to the light absorption layer 34) is formed between the insulating layer 56 (substrate 50) and the lower electrode 32, that is, on the surface 56a of the insulating layer 56.
It is known that when an alkali metal (particularly Na) is diffused into the light absorption layer 34 made of CIGS, the photoelectric conversion efficiency is increased.
The alkali supply layer 58 is a layer for supplying an alkali metal to the light absorption layer 34 and is a layer of a compound containing an alkali metal. In the present invention, such an alkali supply layer 58 is provided between the insulating layer 56 and the lower electrode 32, so that when the light absorption layer 34 is formed, the alkali metal passes through the lower electrode 32 to the light absorption layer 34. It can diffuse and improve the conversion efficiency of the light absorption layer 34.

The alkali supply layer 58 is not limited, and a compound containing an alkali metal (a composition containing an alkali metal compound) such as NaO ₂ , Na ₂ S, Na ₂ Se, NaCl, NaF, or sodium molybdate is a main component. Various things are available. In particular, a compound containing SiO ₂ (silicon oxide) as a main component and NaO ₂ (sodium oxide) is preferable.
The compound of SiO ₂ and NaO ₂ have poor moisture resistance, since tends to carbonate was separated Na component, a metal component with added Ca more oxide that was three components Si-Na-Ca preferable.

In the present invention, the alkali metal supply source to the light absorption layer 34 is not limited to the alkali supply layer 58 alone.
For example, when the insulating layer 56 is the above-described porous anodic oxide film, a compound containing an alkali metal is introduced into the porous layer of the insulating layer 56 in addition to the alkali supply layer 58, so that the light absorption layer 34 may be an alkali metal supply source. Alternatively, the alkali supply layer 58 may not be provided, and a compound containing an alkali metal may be introduced only into the porous layer of the insulating layer 56 to serve as an alkali metal supply source to the light absorption layer 34.
As an example, when the alkali supply layer 58 is formed by sputtering, only the alkali supply layer 58 in which no compound containing an alkali metal exists in the insulating layer 56 can be formed. In addition, the insulating layer 56 is a porous anodic oxide film, and when the alkali supply layer 58 is formed by sol-gel reaction or dehydration drying of a sodium silicate aqueous solution, not only the alkali supply layer 58 but also the insulating layer 56 is formed. By introducing a compound containing an alkali metal into the porous layer, both the insulating layer 56 and the alkali supply layer 58 can serve as an alkali metal supply source to the light absorption layer 34.

In the solar cell submodule 12, the lower electrode 32 is formed on the alkali supply layer 58 so as to be arranged with a predetermined gap 33 from the adjacent lower electrode 32. Further, a light absorption layer 34 is formed on the lower electrode 32 while filling the gaps 33 of the lower electrodes 32. A buffer layer 36 is formed on the surface of the light absorption layer 34.
The light absorption layer 34 and the buffer layer 36 are arranged on the lower electrode 32 with a predetermined gap 37. Note that the gap 33 between the lower electrode 32 and the light absorption layer 34 (buffer layer 36) are formed at different positions in the arrangement direction of the solar cells 40.

Further, an upper electrode 38 is formed on the surface of the buffer layer 36 so as to fill the gap 37 of the light absorption layer 34 (buffer layer 36).
The upper electrode 38, the buffer layer 36 and the light absorption layer 34 are arranged with a predetermined gap 39. The gap 39 is provided at a position different from the gap between the lower electrode 32 and the gap between the light absorption layer 34 (buffer layer 36).
In the solar battery submodule 12, each solar battery cell 40 is electrically connected in series in the longitudinal direction of the substrate 50 (arrow L direction) by the lower electrode 32 and the upper electrode 38.

The lower electrode 32 is composed of, for example, a Mo electrode. The light absorption layer 34 is composed of a semiconductor compound having a photoelectric conversion function, for example, a CIGS film. Further, the buffer layer 36 is made of, for example, CdS, and the upper electrode 38 is made of, for example, ZnO.
The solar battery cell 40 is formed to extend long in the width direction orthogonal to the longitudinal direction L of the substrate 50. For this reason, the lower electrode 32 and the like also extend long in the width direction of the substrate 50.

As shown in FIG. 3, a first conductive member 42 is connected on the lower electrode 32 at the right end. The first conductive member 42 is for taking out an output from a negative electrode to be described later.
The first conductive member 42 is, for example, an elongated belt-like member, extends substantially linearly in the width direction of the substrate 50, and is connected to the lower electrode 32 at the right end. As shown in FIG. 3, the first conductive member 42 is formed, for example, by coating a copper ribbon 42 a with a coating material 42 b made of indium copper alloy. The first conductive member 42 is connected to the lower electrode 32 by, for example, ultrasonic soldering.

On the other hand, a second conductive member 44 is formed on the lower electrode 32 at the left end.
The second conductive member 44 is for taking out the output from the positive electrode, which will be described later, to the outside. Like the first conductive member 42, the second conductive member 44 is a strip-like member that extends substantially linearly in the width direction of the substrate 50. And connected to the lower electrode 32 at the left end.
The second conductive member 44 has the same configuration as the first conductive member 42. For example, a copper ribbon 44a is covered with a coating material 44b of indium copper alloy.

  In addition, the light absorption layer 34 of the photovoltaic cell 40 of this embodiment is comprised by CIGS, and can be manufactured with the manufacturing method of a well-known CIGS type solar cell.

  In the solar cell submodule 12, when light enters the solar cell 40 from the upper electrode 38 side, this light passes through the upper electrode 38 and the buffer layer 36, and an electromotive force is generated in the light absorption layer 34. For example, a current from the upper electrode 38 toward the lower electrode 32 is generated. The arrows shown in FIG. 3 indicate the direction of current, and the direction of electron movement is opposite to the direction of current. For this reason, in the photoelectric conversion unit 48, the leftmost lower electrode 32 in FIG. 3 is a positive electrode (positive electrode), and the rightmost lower electrode 32 is a negative electrode (negative electrode).

In the present embodiment, the electric power generated in the solar cell submodule 12 can be taken out of the solar cell submodule 12 from the first conductive member 42 and the second conductive member 44.
In the present embodiment, the first conductive member 42 is a negative electrode, and the second conductive member 44 is a positive electrode. Further, the first conductive member 42 and the second conductive member 44 may have opposite polarities, and are appropriately changed depending on the configuration of the solar battery cell 40, the solar battery submodule 12 configuration, and the like.
Moreover, in this embodiment, although each photovoltaic cell 40 was formed so that it might be connected in series with the longitudinal direction L of the board | substrate 50 by the lower electrode 32 and the upper electrode 38, it is not limited to this. For example, each solar battery cell 40 may be formed such that each solar battery cell 40 is connected in series in the width direction by the lower electrode 32 and the upper electrode 38.

  In the solar cell 40, the lower electrode 32 and the upper electrode 38 are both for taking out the current generated in the light absorption layer 34. Both the lower electrode 32 and the upper electrode 38 are made of a conductive material. The upper electrode 38 on the light incident side needs to have translucency.

The lower electrode (back electrode) 32 is made of, for example, Mo, Cr, or W, and a combination thereof. The lower electrode 32 may have a single layer structure or a laminated structure such as a two-layer structure. The lower electrode 32 is preferably made of Mo.
The lower electrode 32 preferably has a thickness of 100 nm or more, and more preferably 0.45 to 1.0 μm.
The method for forming the lower electrode 32 is not particularly limited, and can be formed by a vapor phase film forming method such as an electron beam evaporation method or a sputtering method.

The upper electrode (transparent electrode) 38 is made of, for example, ZnO to which Al, B, Ga, Sb or the like is added, ITO (indium tin oxide), SnO ₂ , or a combination thereof. The upper electrode 38 may have a single layer structure or a laminated structure such as a two-layer structure. Further, the thickness of the upper electrode 38 is not particularly limited, and is preferably 0.3 to 1 μm.
The formation method of the upper electrode 38 is not particularly limited, and can be formed by a vapor deposition method such as an electron beam evaporation method or a sputtering method, or a coating method.

The buffer layer 36 is formed to protect the light absorption layer 34 when the upper electrode 38 is formed and to transmit light incident on the upper electrode 38 to the light absorption layer 34.
The buffer layer 36 is made of, for example, CdS, ZnS, ZnO, ZnMgO, ZnS (O, OH), or a combination thereof.
The buffer layer 36 preferably has a thickness of 0.03 to 0.1 μm. The buffer layer 36 is formed by, for example, a CBD (chemical bath) method.

The light absorption layer 34 is a layer that absorbs light that has passed through the upper electrode 38 and the buffer layer 36 and generates a current, and has a photoelectric conversion function. The light absorption layer 34 is composed of a CIGS film, and the CIGS film is made of a semiconductor having a chalcopyrite crystal structure. The composition of the CIGS film is, for example, Cu (In _1-x Ga _x ) Se ₂ (CIGS).

As a CIGS film forming method, 1) a multi-source deposition method, 2) a selenization method, 3) a sputtering method, 4) a hybrid sputtering method, and 5) a mechanochemical process method are known.
Other CIGS film formation methods include screen printing, proximity sublimation, MOCVD, and spray (wet film formation). For example, a fine particle film containing a group Ib element, a group IIIb element, and a group VIb element is formed on a substrate by a screen printing method (wet film forming method) or a spray method (wet film forming method), and then pyrolyzed ( At this time, a crystal having a desired composition can be obtained by performing a thermal decomposition treatment in a VIb group element atmosphere (JP-A-9-74065, JP-A-9-74213, etc.).
Such a film forming method shows good photoelectric conversion efficiency if CIGS is formed on the substrate as long as the temperature is 500 ° C. or higher, but the process time is short in consideration of manufacturing in a roll-to-roll method. Multisource deposition is preferred. In particular, the bilayer method is suitable.

As described above, the solar cell sub-module 12 of the present invention is manufactured by manufacturing the solar cells 40 in series on the substrate 50 described above. What is necessary is just to carry out similarly to a battery.
Hereinafter, an example of the manufacturing method of the solar cell submodule 12 shown in FIG. 3 will be described.

First, the substrate 50 formed as described above is prepared. Next, the alkali supply layer 58 is formed on the surface of the insulating layer 56 of the substrate 50 by, for example, sputtering using soda lime glass as a target or a sol-gel method using an alkoxide containing Si and Na.
Next, a Mo film to be the lower electrode 32 is formed on the surface of the alkali supply layer 58 by sputtering using, for example, a film forming apparatus.
Next, using a laser scribing method, for example, a predetermined position of the Mo film is scribed to form a gap 33 extending in the width direction of the substrate 50. Thereby, the lower electrodes 32 separated from each other by the gap 33 are formed.

Next, a CIGS film is formed as a light absorption layer 34 (p-type semiconductor layer) so as to cover the lower electrode 32 and fill the gap 33. This CIGS film is formed by any of the film forming methods described above.
Next, a CdS layer (n-type semiconductor layer) to be the buffer layer 36 is formed on the light absorption layer 34 (CIGS film) by, for example, a CBD (chemical bath) method. Thereby, a pn junction semiconductor layer is formed.
Next, a gap 37 extending in the width direction of the substrate 50 and reaching the lower electrode 32 is formed by scribing a predetermined position different from the gap 33 in the arrangement direction of the solar cells 40 using, for example, a laser scribing method. To do.

Next, on the buffer layer 36, for example, an ITO layer, a ZnO layer to which Al, B, Ga, Sb, or the like is added is formed by sputtering or coating so as to fill the gap 37. To do.
Next, the gaps 33 and 37 are gaps reaching a lower electrode 32 extending in the width direction of the substrate 50 by scribing a predetermined position different in the arrangement direction of the solar cells 40 using, for example, a laser scribing method. 39 is formed. Thereby, the photovoltaic cell 40 is formed.

Next, the solar cells 40 formed on the lower electrodes 32 at the left and right ends in the longitudinal direction L of the substrate 50 are removed by, for example, laser scribing or mechanical scrub, and the lower electrodes 32 are exposed. Next, the first conductive member 42 is connected to the lower electrode 32 at the right end, and the second conductive member 44 is connected to the lower electrode 32 at the left end using, for example, ultrasonic soldering.
Thereby, as shown in FIG. 3, the solar cell submodule 12 in which the plurality of solar cells 40 are electrically connected in series can be manufactured.

  Here, a schematic cross-sectional view of a conventional solar cell module is shown in FIGS. A conventional solar cell module 100 a shown in FIG. 6 has a water vapor barrier film 106 via an adhesive 104 below the surface protective layer 102, and the adhesive is interposed between the water vapor barrier film 106 and the back surface protective layer 112. A solar cell sub-module 110 surrounded by 108 is provided. The conventional solar cell module 100b of FIG. 7 differs from the solar cell module 100a shown in FIG. 6 in that a sealing material 114 is provided on the side end face 113, and the other configuration is the same as the solar cell module 100a. The same.

  In general, the surface of the solar cell submodule is formed of a transparent conductive film such as an ITO film, a ZnO (Al) film, or a ZnO (B) film. These transparent conductive films are very sensitive to moisture due to their materials. In the case of the solar cell module 100 a configured as shown in FIG. 6, the side end surface 113 of the adhesive 108 surrounding the solar cell submodule 110 is exposed to the outside, and moisture enters the side end surface 113 and the solar cell. It reaches the surface of the sub-module 100 and raises the resistance of the transparent conductive film, or reaches the junction under the transparent conductive film to generate a leakage current, thereby causing a problem of deteriorating the characteristics of the solar cell module. .

  On the other hand, in the case of the solar cell module 100b having the configuration shown in FIG. 7, since the side end face 113 of the adhesive 108 is covered with the sealing material 114, it is possible to prevent moisture from entering from the side end face 113 at first glance. looks like. However, the outer periphery of the solar cell module 100b bends due to the difference in thermal expansion and contraction of the surface protective layer 102, the water vapor barrier film 106, the back surface protective layer 112, the adhesives 104 and 108, etc. in a high temperature and high humidity environment. In addition, the peripheral edge of the sealing material 114 is peeled off, or a part of the cavity is generated and moisture enters the inside thereof. As a result, moisture intrusion from the side end face 113 of the solar cell module 100b is prevented. I can't.

  On the other hand, in the solar cell module 10 shown in FIG. 1A, the intermediate sealing material 18 is disposed on the inner side of the periphery of the back sheet 16, so that the water vapor barrier film 22 and the back sheet 16 are formed on the intermediate sealing material 18. Since it is located inside the solar cell module 10 joined, it is not exposed to the outside, and the intermediate sealing material 18 is not bent or peeled off due to the difference between thermal expansion and thermal contraction. The intermediate sealing material 18 is provided at least from the back surface 12b of the solar cell submodule 12 to the water vapor barrier film 22, and the intermediate sealing material 18 contacts the water vapor barrier film 22 and seals the adhesive filling material 20. It becomes possible to prevent moisture from entering from the 20 side surfaces, and at least moisture entry from the surface 12a side (upper side) of the solar cell submodule 12 can be suppressed. In addition, the solar cell module 10 can reduce the generation of corrosive substances generated by the reaction of moisture and the adhesive constituting the adhesive filler 20, for example, acetic acid, and can exhibit stable performance over a long period of time. can do.

  In the solar cell module 10 shown in FIG. 1A, the intermediate sealing material 18 is provided from the back surface 12b of the solar cell submodule 12 to the water vapor barrier film 22, but the intermediate sealing material 18 is used as a back sheet. 16, the second adhesive layer 14 may be separated by contacting it. With such a configuration, the intermediate sealing material 18 can also suppress moisture intrusion from the second adhesive layer 14, and corrosive substances generated by the reaction between the moisture and the second adhesive layer 14 can be prevented. It becomes possible to reduce more effectively, and it is possible to suppress a decrease in conversion efficiency of the solar cell submodule 12 due to an improvement in resistance due to alteration of the transparent electrode of the solar cell submodule 12 and to exhibit stable performance over a long period of time. The solar cell module 10 can be made.

Moreover, in this embodiment, by using a plastic sheet for the surface protective layer 26, mechanical strength and impact strength such as wind pressure resistance and sag resistance that are equal to or higher than that of white tempered glass can be obtained. Moreover, if the same thickness as the glass for the density of the glass 2.5 g / cm ^3, the plastic sheet can mass so 1.1~1.2g / cm ³ to less than 50%. Here, in general, the thickness of the white plate tempered glass is 3 mm, but by reducing the thickness of the surface protective layer 26 to 1 to 2 mm, the mass per unit area is 1.2 to 2.4 kg. / M ² . Thereby, it can reduce in weight to 16 to 32% compared with the case where white board tempered glass is used.
In addition, the heat treatment suppresses the generation of wrinkles and the like due to the heat shrinkage that occurs during the vacuum lamination, and the decrease in the amount of incident light on the solar cell submodule 12 can also be suppressed.

Next, a second embodiment will be described.
FIG. 4: is typical sectional drawing which shows the arrangement | positioning state of each member before the vacuum lamination of the solar cell module of the 2nd Embodiment of this invention.
In the present embodiment, the same components as those of the solar cell module 10 shown in FIGS. 1A and 1B are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the solar cell module 10a of the present embodiment is provided with an intermediate sealing material 18 as compared to the solar cell module 10 of the first embodiment (see FIGS. 1A and 1B). The difference is that the frame member 60 is provided at the peripheral portion β of the second adhesive filling layer 14, the back sheet 16, the water vapor barrier film 22, the first adhesive filling layer 24, and the surface protective layer 26. The remaining configuration is the same as that of the solar cell module 10 of the first embodiment, and thus detailed description thereof is omitted.

  In the solar cell module 10a of the present embodiment, the frame member 60 is for improving the mechanical resistance of the solar cell module 10a and improving the moisture diffusion resistance and moisture resistance from the peripheral edge β. The frame member 60 includes an outer edge sealing material 62 and an outer frame material 64, the outer edge sealing material 62 is provided on the inner side, and the outer frame material 64 is provided on the outer side.

For the outer edge sealing material 62, for example, butyl rubber, polyisoprene, or isoprene exhibiting thermoplasticity is used.
The outer frame member 64 may be formed of a foil shape or a frame shape. The outer frame material 64 can be formed using, for example, aluminum, an aluminum alloy, copper, or a copper alloy. For example, when a metal foil is used as the outer frame member 64, aluminum, an aluminum alloy, copper, or a copper alloy can be used. The thickness of the metal foil is, for example, 50 to 300 μm. The metal foil may be provided with an adhesive material in advance.

The outer frame member 64 may be a metal foil tape in which a black PET film is bonded to a metal foil from the viewpoint of aesthetics and design of the solar cell module 10a.
When further moisture resistance is required, for example, butyl rubber is used for the outer edge sealing material 62, and an L-shaped aluminum frame is used for the outer frame material 64.
Also in the solar cell module 10a of the present embodiment, the above-described fluorine-based transparent resin film can be provided on the surface 26a of the surface protective layer 26 as in the first embodiment.

The solar cell module 10a of this embodiment can be produced as follows. First, the second adhesive filling layer 14 and the back sheet 16 are laminated and disposed on the back surface 12b side of the solar cell submodule 12 as in the first embodiment. Next, as in the first embodiment, the adhesive filler 20, the water vapor barrier film 22, the first adhesive filler layer 24, and the surface protective layer 26 are laminated and disposed on the surface 12a side of the solar cell submodule 12. To do. Thereby, as shown in FIG. 4, it will be in the state by which each member was laminated | stacked and arrange | positioned. Thereafter, in a state where the respective members are stacked and arranged, similarly to the first embodiment, for example, vacuum lamination is performed at a temperature of 130 to 140 ° C. under conditions of vacuum / press / hold for a total of 15 to 30 minutes.
Thereafter, the outer edge sealing material 62 of the frame member 60 is provided so as to cover the peripheral edge β, part of the surface protective layer 26 surface and part of the surface of the backsheet 16. Thereafter, the outer frame material 64 is bonded onto the outer edge sealing material 62. Thereby, the solar cell module 10a of this embodiment is formed.
In addition, also in this embodiment, when producing the solar cell module 10a, similarly to the first embodiment, on the surface 26a of the surface protective layer 26, the above-described fluorine-based transparent resin film is laminated and disposed. In this state, the solar cell module can be manufactured by vacuum lamination.
In the solar cell module 10a of the present embodiment, the same effect as that of the solar cell module 10 of the first embodiment can be obtained.

Next, a third embodiment will be described.
FIG. 5: is typical sectional drawing which shows the arrangement | positioning state of each member before the vacuum lamination of the solar cell module of the 3rd Embodiment of this invention.
In the present embodiment, the same components as those of the solar cell module 10 shown in FIGS. 1A and 1B are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the solar cell module 10b of the present embodiment has a peripheral edge of the solar cell module 10 as compared to the solar cell module 10 of the first embodiment (see FIGS. 1A and 1B). The point that the frame member 60 is provided in the part α is different, and the other configuration is the same as that of the solar cell module 10 of the first embodiment, and thus detailed description thereof is omitted.

In the solar cell module 10b of the present embodiment, the frame member 60 is for improving mechanical resistance and improving moisture diffusion resistance and moisture resistance from the peripheral portion α.
In addition, since the frame member 60 is the structure similar to the solar cell module 10a of 2nd Embodiment, the detailed description is abbreviate | omitted.
Also in the solar cell module 10b of this embodiment, the above-mentioned fluorine-based transparent resin film can be provided on the surface 26a of the surface protective layer 26 as in the first embodiment.

The solar cell module 10b of this embodiment can be manufactured as follows. First, as in the first embodiment, as shown in FIG. 1B, the second adhesive filling layer 14 and the back sheet 16 are arranged on the back surface 12 b side of the solar cell submodule 12, and the solar cell sub An adhesive filler 20, a water vapor barrier film 22, a first adhesive filler layer 24, and a surface protective layer 26 are disposed on the surface 12a side of the module 12. Thereby, as shown in FIG. 5, it will be in the state which each member laminated | stacked. Thereafter, as in the first embodiment, for example, vacuum lamination is performed at a temperature of 130 to 140 ° C. under a total of 15 to 30 minutes of vacuum / press / hold.
Thereafter, the outer edge sealing material 62 of the frame member 60 is provided so as to cover the peripheral edge portion α, part of the surface of the surface protective layer 26 and part of the surface of the back sheet 16. Thereafter, the outer frame material 64 is bonded onto the outer edge sealing material 62. Thereby, the solar cell module 10b of this embodiment is formed.
In the present embodiment, when the solar cell module 10b is manufactured, the above-described fluorine-based transparent resin film is laminated on the surface 26a of the surface protective layer 26, as in the first embodiment, In this state, the solar cell module can be manufactured by vacuum lamination.
In the solar cell module 10b of the present embodiment, the same effect as that of the solar cell module 10 of the first embodiment can be obtained, and further, mechanical resistance, moisture diffusion resistance, and moisture resistance can be improved. .

  The present invention is basically configured as described above. As mentioned above, although the solar cell module of this invention and its manufacturing method were demonstrated in detail, this invention is not limited to the said embodiment, In the range which does not deviate from the main point of this invention, you may make a various improvement or change. Of course.

Hereinafter, the solar cell module of the present invention will be described more specifically.
In this example, the solar cell modules of Examples 1 to 5 and Comparative Example 1 shown below were produced and their performance was evaluated.

Example 1
A solar cell module 10 shown in FIG. 1 including a solar cell submodule 12 having a substrate structure and using a CIGS film as a light absorption layer was produced.
As the water vapor barrier film 22, a film obtained by laminating an organic film and an inorganic film using a PET film as a base material was used.
Mitsui Chemicals Fabro Solar Eva (EVA) was used for the adhesive filler 20, the first adhesive filler layer 24, and the second adhesive filler layer 14.
For the surface protective layer 26, a polycarbonate sheet having a thickness of 1.5 mm subjected to heat treatment described later was used. The polycarbonate sheet used as the surface protective layer 26 was heat-treated in air at 130 ° C. for 3 hours in advance in order to suppress warpage due to thermal shrinkage in the vacuum laminating process. The heat shrinkage rate of the polycarbonate sheet after the heat treatment is 0.01%.

Furthermore, for the back sheet 16, a repnea TFB MD manufactured by Lintec Corporation was used.
Moreover, as the intermediate sealing material 18, a sheet material of hot melt butyl rubber (M-155) manufactured by Yokohama Rubber Co., Ltd. is used, cut into a mouth shape, the width of the intermediate sealing material 18 is 5 mm, the outer periphery of the intermediate sealing material 18 and the sun. The distance from the periphery of the battery module 10 was 10 mm.
In the production of Example 1, a total of 20 vacuums / presses / holds at a temperature of 140 ° C. using a vacuum laminator having lifting and lowering means, buffer plates, and heating means in a state where such materials are laminated and arranged. The solar cell module 10 was produced under the lamination conditions for 1 minute.

(Example 2)
The solar cell module 10a shown in FIG. 3 was produced. In addition, the same thing as Example 1 was used except the frame member 60. FIG.
For the frame member 60, butyl rubber was used as the outer edge sealing material 62, and Al foil tape was used for the outer frame material 64. In addition, Yokohama rubber M-155P was used for the butyl rubber.
In the production of Example 2, the second adhesive filling layer 14 and the back sheet 16 are disposed on the back surface 12b side of the solar cell submodule 12, and the adhesive filler 20 and water vapor are disposed on the surface 12a side of the solar cell submodule 12. After disposing the barrier film 22, the first adhesive filling layer 24, and the surface protective layer 26, vacuum lamination is performed at a temperature of 140 ° C. under lamination conditions of vacuum / press / hold for a total of 20 minutes. Then, butyl rubber was melted at 150 to 190 ° C., and the laminated side was coated with butyl rubber melted at a width of 5 to 10 mm from the peripheral edge to the peripheral edge of the four sides, and the surface of the surface protective layer and the surface of the back protective layer, and cooled and cured. Later, the AL foil tape was attached so as to surround the butyl rubber, and the frame member 60 was provided to produce the solar cell module 10a.

(Example 3)
The solar cell module 10a shown in FIG. 3 was produced. In addition, the same thing as Example 1 was used except the frame member 60. FIG. A silicone seal material is used for the frame member 60 as the outer edge seal material 62. The RTV sealing material KE-45 of Shin-Etsu Chemical Co., Ltd. was used for the silicone sealing material. Further, an L-shaped aluminum frame was used for the outer frame member 64.
In the production of Example 3, a laminated material was produced in the same manner as in Example 2, and then a silicone sealant was applied and embedded in the L-shaped aluminum frame groove in advance, and the four sides of the laminated material were The aluminum frame was fixed by screwing it in the groove of the aluminum frame. Thereafter, the frame was formed by allowing the silicone sealing material to harden for 7 days at room temperature, thereby providing a solar cell module 10a.

Example 4
A solar cell module 10b shown in FIG. 5 was produced. In addition, the same thing as Example 1 was used except the frame member 60. FIG.
In the frame member 60, butyl rubber was used for the outer edge sealing material 62, and an L-shaped aluminum frame was used for the outer frame material 64. In addition, Yokohama rubber M-155P was used for the butyl rubber.
When producing Example 4, a solar cell module was produced by vacuum lamination as shown in Example 1. Thereafter, butyl rubber is melted at 150 to 190 ° C., applied to and embedded in an L-shaped aluminum frame groove, and the peripheral edges of the four sides of the solar cell module are sandwiched in the aluminum frame groove, and then at 90 ° C. for 30 minutes in a thermostatic bath. Baking and bonding were performed, and the aluminum frame was screwed and fixed, and the frame member 60 was attached, thereby producing the solar cell module 10b.

(Example 5)
The solar cell module 10 shown in FIG. 1 was produced. In addition, the solar cell module 10 was produced on the same manufacturing conditions as Example 1 using the same thing as Example 1 except having used the acrylic resin sheet | seat with a thickness of 1.5 mm for the surface protective layer 26. FIG.

(Example 6)
The solar cell module 10 shown in FIG. 1 was produced. A polycarbonate sheet having a thickness of 1.5 mm was used for the surface protective layer 26, and the surface of this polycarbonate sheet was subjected to corona treatment under conditions of 150 W and 0.5 m / min to make the surface hydrophilic. Then, Example 1 except having laminated | stacked the 25-micrometer-thick ETFE film on the surface of the polycarbonate sheet through the adhesion filling layer (Solar EVA (EVA) by Mitsui Chemicals Fabro Co., Ltd.) as a fluorine-type transparent resin film. The solar cell module 10 was manufactured under the same manufacturing conditions as in Example 1 using the same as the above.

(Comparative Example 1)
The solar cell module 10 shown in FIG. 1 was produced. In addition, the solar cell module 10 was produced on the same manufacturing conditions as Example 1 using the same thing as Example 1 except having used the FluonETFE film by Asahi Glass Co., Ltd. whose thickness is 25 micrometers for the surface protective layer 26. FIG.

(Comparative Example 2)
The solar cell module 10 shown in FIG. 1 was produced. For the surface protective layer 26, a polycarbonate sheet having a thickness of 1.5 mm was used. The polycarbonate sheet used as the surface protective layer 26 is not subjected to a pre-heat treatment, and the thermal shrinkage of this polycarbonate sheet is 0.07%. Except this, the same thing as Example 1 was used, and the solar cell module 10 was produced on the same manufacturing conditions as Example 1. FIG.

  About the produced 6 types of solar cell modules, the conversion efficiency after a descending test and a dump heat test (left in an environment of a temperature of 85 ° C. and a humidity of 85 RH for 1000 hours) was measured. The results are shown in Table 2 below. Here, the yield test was conducted based on the evaluation standard of the international standard IEC-61646 10.17 for thin film solar cells. Moreover, the falling test and the dump heat test were performed continuously.

  In the dump heat test, when the conversion efficiency of the solar cell module maintained 90% or more of the initial value, it was evaluated as ◎, and the conversion efficiency of the solar cell module was 80% or more and less than 90% of the initial value. The case where the conversion efficiency of the solar cell module was 60% or more and less than 80% of the initial value was evaluated as △, and the case where the conversion efficiency of the solar cell module was less than 60 of the initial value was evaluated as x. evaluated.

  As shown in Table 2 above, Examples 1, 4, 5, and 6 have a structure in which an intermediate sealing material is provided on the inner side of the peripheral edge, and Examples 2 and 3 have no intermediate sealing material. The frame member is provided. In any of Examples 1 to 6, the mechanical strength of the surface protective layer is increased, and the conversion efficiency of the solar cell module is deteriorated by suppressing the separation of the peripheral portion and the generation of cavities and suppressing the diffusion of moisture from the peripheral portion. Was able to be suppressed.

On the other hand, in Comparative Example 1, the film of the surface protective layer was thin and the impact strength was weak, so that a good result was not obtained in the yield test. Moreover, the solar cell sub-module itself, the barrier film or the anodized layer that is the insulating layer of the substrate cracked due to the falling test, and current leakage to the substrate occurred, or the dump heat test after the falling test caused moisture Is intruded from the crack generation part of the barrier film, the transparent electrode of the solar cell submodule is altered, the series resistance is increased, and the conversion efficiency of the solar cell module is considered to be lowered.
In Comparative Example 2, when the solar cell module was produced, an upwardly concave warp occurred. In Comparative Example 2, it was considered that good results were not obtained for the yield test because of the occurrence of warpage of the top and bottom. In addition, the dump heat test after the falling test invaded the moisture from the part where the warp occurred, the transparent electrode of the solar cell sub-module was altered, the series resistance was increased, and the conversion efficiency of the solar cell module was reduced. Conceivable.

10, 10a, 10b Solar cell module 12 Solar cell sub-module 14 Adhesive filling layer 16 Back sheet 18 Intermediate sealing material 20 Adhesive filling material 22 Barrier film 24 First adhesive filling layer 24
26 Surface Protection Layer 40 Solar Cell 50 Substrate 60 Frame Member 62 Outer Edge Seal Material 64 Outer Frame Material

Claims (14)

A water vapor barrier film, a first adhesive filling layer and a surface protective layer are laminated on the surface side of the solar cell submodule sealed with the adhesive filler, and a second adhesion is provided on the back side of the solar cell submodule. A solar cell module provided by laminating a filling layer and a back surface protective layer,
The solar cell submodule has a light absorption layer composed of a CIGS film,
Of the surface protective layer and the back surface protective layer, at least the surface protective layer is made of a plastic sheet, and the plastic sheet has a thermal shrinkage rate of 0.04% or less. .   The solar cell module according to claim 1, wherein the plastic sheet is made of a polycarbonate resin or an acrylic resin, and the plastic sheet has a thickness of 0.5 to 2.5 mm.   The solar cell module according to claim 1 or 2, wherein an intermediate sealing material for preventing water vapor intrusion is provided 5 to 30 mm inside from the peripheral edge of the back surface protective layer.   A frame member provided at a peripheral edge, the frame member includes a sealing material provided on an inner side and an outer frame material provided on an outer side, and the sealing material is made of butyl rubber or silicone resin; The solar cell module according to any one of claims 1 to 3, wherein the outer frame member is made of an aluminum frame or a metal foil tape.   The solar cell module according to any one of claims 1 to 4, wherein the substrate used in the solar cell submodule is aluminum, stainless steel, and a clad material of aluminum, or a clad material of aluminum and stainless steel.   The solar cell module according to any one of claims 3 to 5, wherein the intermediate sealing material is made of butyl rubber, polyisoprene or isoprene.   The solar cell module of any one of Claims 1-6 by which the fluorine-type transparent resin film is provided on the said surface protective layer.   The solar cell module according to claim 7, wherein the fluorine-based transparent resin film is composed of ETFE, PTFE, PFA, or PVDF. A water vapor barrier film, a first adhesive filling layer and a surface protective layer are laminated on the surface side of the solar cell submodule sealed with the adhesive filler, and a second adhesion is provided on the back side of the solar cell submodule. A method for producing a solar cell module in which a filling layer and a back surface protective layer are laminated,
The solar cell submodule has a light absorption layer composed of a CIGS film,
Of the surface protective layer and the back surface protective layer, at least the surface protective layer is composed of a plastic sheet,
Heat treating the plastic sheet at a temperature of 100 to 140 ° C. in advance;
On the surface side of the solar cell submodule, an adhesive filler, a water vapor barrier film, a first adhesive filler layer, and a heat-treated plastic sheet to be the surface protective layer are laminated and disposed, and the solar cell submodule A step of laminating and arranging the second adhesive filling layer and the back surface protective layer on the back surface side;
And a step of vacuum laminating in a state where the plurality of layers are stacked and disposed.   Furthermore, the manufacturing method of the solar cell module of Claim 9 which arrange | positions the intermediate | middle sealing material for water vapor | steam invasion inside 5-30 mm inside from the peripheral part of the said back surface protective layer in the process arrange | positioned in the said lamination | stacking.   11. The solar cell module according to claim 9, further comprising a step of providing, after the vacuum laminating step, a frame member provided with a sealing material on an inner side and an outer frame material on an outer side at a peripheral portion of the vacuum laminated material. Production method.   The said plastic sheet is comprised with the polycarbonate resin or the acrylic resin, and the thickness of the said plastic sheet is 0.5-2.5 mm, The manufacture of the solar cell module of any one of Claims 9-11 Method.   Furthermore, the manufacturing method of the solar cell module of any one of Claims 9-12 which arrange | positions a fluorine-type transparent resin film on the said plastic sheet in the process arrange | positioned in the said lamination | stacking.   The method for manufacturing a solar cell module according to claim 13, wherein the fluorine-based transparent resin film is made of ETFE, PTFE, PFA, or PVDF.