JP2013089749A - Frameless solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frameless solar cell module which achieves predetermined performance for a long time, is stably used, and is lightweight and inexpensive.SOLUTION: In a frameless solar cell module, a surface protection layer is provided on the front surface side of a solar cell sub-module which is sealed by an adhesive filler, and a rear surface protection layer is provided on the rear surface side of the solar cell sub-module. Further, a back sheet is provided between the rear surface protection layer and the adhesive filler. Peripheral seals formed by a seal material containing an absorbent are provided at the inner sides of the surface protection layer and the rear surface protection layer and the outer side of the adhesive filler.

Description

  The present invention relates to a frameless type frameless solar cell module without an outer frame, and more particularly to a frameless solar cell module that is lightweight and highly reliable.

  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 things for improving the waterproofness of a solar cell module are made. In addition, a frameless solar cell module has been proposed for cost reduction. Conventionally, peripheral sealing is performed by filling the frame with a sealing material such as silicone resin or butyl rubber. However, the frameless structure exposes the peripheral sealing directly to the outside environment, so it is highly reliable, especially moisture sealing. As for the properties, it is necessary to select a structure and material with sufficient consideration, and various types have been proposed (Patent Documents 1 to 7 and the like).

  Regarding the peripheral seal of the frameless solar cell module, for example, Patent Document 1 discloses a solar cell module in which a plurality of crystalline Si cells are arranged, and the periphery of the back material is inside the surface protection plate, and the weather-resistant film and the seal are sealed. A frameless solar cell module having a peripheral seal structure in which a surface protective material is filled with a stop resin (silicone resin) is disclosed.

In Patent Document 2, a thin-film solar cell layer is formed on one side and an insulator layer side surface of a first light-transmitting substrate in which an insulator layer is provided on the entire surface of the thin-film solar cell layer; Frameless sun with a structure in which a peripheral edge is terminated with a synthetic resin layer or a structure that covers the outside of the peripheral edge. A battery module is disclosed.
Patent Document 3 discloses a frameless solar cell module in which a rear surface protective layer glass is made larger than a surface protective layer glass and arranged on the outside, and a peripheral edge is filled with an encapsulant (EVA).

In Patent Document 4, a solar cell submodule, a cover glass that covers the light receiving surface of the solar cell submodule, and a space between the solar cell submodule and the coverglass are filled, and the solar cell submodule and the coverglass are bonded. A solar cell module having a filler to be held and an adsorbent having hygroscopicity and having an adsorbent installed between the upper surface of the peripheral end portion of the solar cell submodule and the cover glass is disclosed.
Patent Document 5 discloses a sealing structure at the end of a frameless solar cell module, in which the sealing material contains polyisobutylene / butyl rubber and metal hydroxide.

Patent Document 6 discloses a frameless solar cell module that includes a solar cell panel and has a surface protective layer and a back surface protective layer of the same size, and the outer peripheral edge is covered with a hot melt adhesive.
The solar cell panel of Patent Document 6 includes a solar cell element, a surface protection unit that is disposed on the front side of the solar cell element and protects the solar cell element, and a back surface that is disposed on the back side of the solar cell element and protects the solar cell element. A peripheral edge covering portion bonded to the peripheral edge formed by the end surface of the front surface protective portion and the end surface of the back surface protective portion. The peripheral edge covering portion is made of a hot melt adhesive.

Patent Document 7 includes a weather-resistant protective film, an ultraviolet cut film, a gas barrier film, a getter material film, a sealing material, a solar cell element, a sealing material, a getter material film, a gas barrier film, A thin film solar cell is disclosed that includes a back sheet in this order, and further includes a weatherproof protective film 1 and a sealing material that seals the edge of the back sheet. In the thin film solar cell of patent document 7, light is irradiated from the side (downward in the figure) on which the weather-resistant protective film is formed, and the solar cell element generates power.
In Patent Document 7, the getter material film is a film that absorbs moisture and / or oxygen. Some components of the solar cell element are deteriorated by moisture as described above, and some are deteriorated by oxygen. Therefore, by covering the solar cell element with a getter material film, the solar cell element and the like are protected from moisture and / or oxygen, and the power generation capacity is kept high.

Japanese Patent No. 3785263 JP 9-331079 A JP 2008-288547 A JP 2009-188357 A JP 2010-171400 A JP 2010-192748 A JP 2010-21498 A

However, in Patent Document 1, the back surface protective layer and the back sheet at the peripheral edge are covered with a silicone resin, but the sealing property is low (WVTR10 to 50), and the CIS or CIGS solar cell module is insufficient.
In Patent Document 2, the sealing property is low, and a CIS or CIGS solar cell module is insufficient. In Patent Document 3, when the adhesive layer is directly used for the peripheral seal, moisture cannot be sealed because of high moisture permeability (WVTR> 1).
Moreover, in patent document 4, when the tempered glass of 3.2 mm thickness is used as a surface protective layer, it will be 7.5 kg / m < ² > and the weight of a solar cell module will become heavy.
In Patent Document 5, both the front and back protective layers have a glass structure, and as in Patent Document 4, weight reduction cannot be achieved. In Patent Document 6, since there is a peripheral seal on the outer sides of the front and back protective layers, problems related to reliability such as being easily affected by the mechanical strength of the frameless solar cell module and the external environment are likely to occur.
Furthermore, Patent Document 7 also includes a sealing material that seals the edges of the weatherproof protective film and the back sheet, but this sealing material cannot provide a sufficient moisture sealing effect.

  Here, as a characteristic required for a solar cell module having a long-term reliability of 20 to 30 years, it is a matter of course that the photoelectric conversion efficiency of the solar cell itself is high, but weather resistance, heat resistance, flame resistance It is excellent in water resistance, moisture resistance, wind pressure resistance, yield resistance, and other various characteristics. In addition, it is necessary to reduce the construction cost for installing the solar cell module and the panel itself at a lower price. For heavy-duty solar panels and modules that use conventional tempered glass as the surface protective layer, it costs high for reinforcement work to be fixed on ordinary houses and slate roofs, and light weight to reduce overall cost. Realization of a highly reliable frameless solar cell module that does not use an aluminum frame is desired.

  An object of the present invention is to provide a lightweight and inexpensive frameless solar cell module that solves the problems based on the above-described prior art, exhibits predetermined performance over a long period of time, and can be used stably. .

In order to achieve the above object, according to a first aspect of the present invention, a surface protection layer is provided on the surface side of a solar cell submodule sealed with an adhesive filler, and a back surface is provided on the back surface side of the solar cell submodule. A frameless solar cell module provided with a protective layer, wherein a back sheet is provided between the back protective layer and the adhesive filler, and a peripheral seal made of a sealing material containing an adsorbent The present invention provides a frameless solar cell module provided inside a protective layer and the back surface protective layer, and outside the adhesive filler and the back sheet.
For example, a water vapor barrier film is provided between the surface protective layer and the adhesive filler, and the peripheral seal is provided outside the adhesive filler, the water vapor barrier film, and the back sheet.

  According to a second aspect of the present invention, a surface protective layer made of a plastic sheet is provided on the surface side of the solar cell submodule sealed with an adhesive filler, and a back surface protective layer is provided on the back side of the solar cell submodule. A frameless solar cell module, wherein a water vapor barrier film is provided between the surface protective layer and the adhesive filler, and a back sheet is provided between the back surface protective layer and the adhesive filler. And a peripheral seal made of a sealing material containing an adsorbent is provided inside the laminate of the surface protective layer and the water vapor barrier film and the back surface protective layer, and outside the adhesive filler and the back sheet. The present invention provides a frameless solar cell module.

Moreover, it is preferable that the said surface protective layer is comprised with the plastic sheet or the blue plate glass or white plate glass whose thickness is 0.8-2.0 mm.
Furthermore, it is preferable that the said back surface protective layer is comprised with a metal sheet.
Furthermore, in the solar cell submodule, it is preferable that the light absorption layer is composed of a CIS film or a CIGS film.

  ADVANTAGE OF THE INVENTION According to this invention, the highly reliable flameless solar cell module which considered the light weight and low cost, especially water-sealing property is realizable. Thereby, a flameless solar cell module can exhibit predetermined performance over a long period of time and can be used stably.

(A) is typical sectional drawing which shows the frameless solar cell module of the 1st Embodiment of this invention, (b) is each before vacuum lamination of the frameless solar cell module of Fig.1 (a). It is typical sectional drawing which shows the arrangement | positioning state of a member. It is typical sectional drawing which shows an example of the solar cell submodule used for the frameless solar cell module of the 1st Embodiment of this invention. (A) is typical sectional drawing which shows the frameless solar cell module of the 2nd Embodiment of this invention, (b) is each before vacuum lamination of the frameless solar cell module of Fig.3 (a). It is typical sectional drawing which shows the arrangement | positioning state of a member. (A) is typical sectional drawing which shows the frameless solar cell module of the 3rd Embodiment of this invention, (b) is each before vacuum lamination of the frameless solar cell module of Fig.4 (a). It is typical sectional drawing which shows the arrangement | positioning state of a member. 6 is a schematic cross-sectional view showing a frameless solar cell module of Comparative Example 1. FIG. It is typical sectional drawing which shows the conventional 1st frameless solar cell module. It is typical sectional drawing which shows the conventional 2nd frameless solar cell module. It is typical sectional drawing which shows the conventional 3rd frameless solar cell module. It is typical sectional drawing which shows the conventional 4th frameless solar cell module.

Hereinafter, a frameless solar cell module of 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 frameless solar cell module of the 1st Embodiment of this invention, FIG.1 (b) is the vacuum of the frameless solar cell module of Fig.1 (a). It is typical sectional drawing which shows the arrangement | positioning state of each member before lamination.

As shown in FIG. 1A, the frameless solar cell module 10 is a so-called frameless type in which an outer frame made of aluminum or the like is not provided.
In the frameless solar cell module 10 (hereinafter simply referred to as the solar cell module 10), a second adhesive filler 14 is provided on the back surface 12b of the solar cell submodule 12 so as to cover the solar cell submodule 12. ing. A back sheet 16 is provided under the second adhesive filler 14, and a second adhesive layer 18 is provided under the back sheet 16. A back surface protective layer 20 is provided under the second adhesive layer 18. Thus, the back surface protective layer 20 is provided via the second adhesive filling layer 14.
In addition, the back surface 12b of the solar cell submodule 12 is a surface of the solar cell submodule 12 on which the light absorption layer is not formed. The surface 12 a of the solar cell submodule 12 is a surface on the side where the light absorption layer is formed in the solar cell submodule 12.

A first adhesive filler 22 is provided on the surface 12 a of the solar cell submodule 12 so as to cover the solar cell submodule 12. A water vapor barrier film 24 is provided on the first adhesive filler 22.
A first adhesive filling layer 26 is provided on the water vapor barrier film 24, and a surface protective layer 28 is provided on the first adhesive filling layer 26. As described above, the surface protective layer 28 is provided via the first adhesive filling layer 26.
The solar cell submodule 12 is sealed with a first adhesive filler 22 and a second adhesive filler 14.

  Without touching the back surface 28b of the surface protective layer 28 and the surface 20a of the back surface protective layer 20, and without protruding from the surface protective layer 28 and the back surface protective layer 20, the first adhesive filling layer 26, the water vapor barrier film 24, A peripheral seal 30 is provided outside the first adhesive filler 22, the second adhesive filler 14, the back sheet 16, and the second adhesive filler layer 18 so as to surround them.

  The solar cell module 10 of the present embodiment is, for example, using a vacuum laminator having elevating means, buffer plates, and heating means in a state where the respective members are stacked and arranged as shown in FIG. The solar cell module 10 shown in FIG. 1A can be manufactured by vacuum lamination at a temperature of 130 to 150 ° C. under a total of 15 to 30 minutes of vacuum / press / hold.

Specifically, the peripheral seal 30 is pasted on the four sides of the peripheral edge of the back surface 28 b of the surface protective layer 28 with the surface protective layer 28 facing down. Next, the first adhesive filling layer 26, the water vapor barrier film 24, the first adhesive filler 22, the solar cell submodule 12, the second adhesive filler 14, the back sheet 16, the first inside the peripheral seal 30. Two adhesive filling layers 18 are laminated, and finally the back surface protective layer 20 is laminated so that the peripheral edge is outside the peripheral seal 30. That is, finally, the back surface protective layer 20 is laminated so that the outer periphery of the peripheral seal 30 and the periphery of the back surface protective layer 20 are aligned and overlapped. In addition, the water vapor | steam barrier film 24 is arrange | positioned so that the water vapor | steam barrier layer 24b may become the solar cell submodule 12 side. In this way, the stacked state shown in FIG. And it laminates with a vacuum laminator.
Next, for example, wiring (not shown) taken out on the back surface of the back surface protective layer 20 is soldered to an electrode of a connection box (not shown). Thereby, the solar cell module 10 shown to Fig.1 (a) is producible.

  In the present embodiment, a fluorine-based transparent resin film, which will be described later, is laminated on the surface 28a of the surface protective layer 28, and vacuum lamination is performed in this state 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 first adhesive filler 22 and the second adhesive filler 14 seal the solar cell submodule 12. Examples of the first adhesive filler 22 and the second adhesive filler 14 include ionomer resin, EVA (ethylene vinyl acetate), PVB (polyvinyl butyral), PE (polyethylene), olefin adhesive, and polyurethane adhesive. Etc. can be used. In addition to this, various kinds of materials used as sealing materials in known solar cell modules can be used. Note that the thermoplastic olefin polymer resin and the thermoplastic polyurethane resin are preferable as the first adhesive filler 22 and the second adhesive filler 14 because of excellent adhesiveness.
In order to improve the adhesiveness, the adhesion between the first adhesive filler 22 and the second adhesive filler 14 can be enhanced by applying a primer to the adherend or applying a corona treatment. it can.

The back sheet 16 protects the solar cell module 10 from the back side by preventing moisture permeation, maintaining insulating properties, mechanical impact, and the like.
For the backsheet 16, for example, a laminated structure in which an aluminum foil is sandwiched between resin films such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and PVF (polyvinyl fluoride) is used. There is no particular limitation.
The back sheet 16 is not limited to a film having a laminated structure in which an aluminum foil is sandwiched between the above-described resin films. In addition, the back sheet 16 may be used as a back sheet 16 in a known solar cell module. Various types are available.

The second adhesive filling layer 18 is for bonding the back sheet 16 and the back surface protective layer 20. As the second adhesive filling layer 18, for example, the same material as the first adhesive filling material 22 and the second adhesive filling material 14 can be used. For this reason, detailed description is omitted.
In the second adhesive filling layer 18 as well, the thermoplastic olefin polymer resin and the thermoplastic polyurethane resin are optimal because they are excellent in adhesiveness.

The back surface protective layer 20 protects the solar cell module 10 from the back side.
For the back surface protective layer 20, for example, a metal plate such as a galvalume steel plate, an aluminum plate, an aluminum alloy plate, a stainless steel plate, a clad steel plate of aluminum and stainless steel, or the like can be used. The thickness of the back surface protective layer 20 is 0.3 to 1.0 mm.
As the back surface protective layer 20, various materials used in known solar cell modules can be used in addition to the above. The back surface protective layer 20 is not a steel sheet for weight reduction, but a rubber sheet, a plastic resin honeycomb structure, or a plastic resin containing a glass fiber material or a carbon fiber material (GFRP (glass fiber composite material). CFRP (carbon fiber composite material)) or the like can also be used.

The water vapor barrier film 24 is for protecting the solar cell submodule 12 from moisture.
As the water vapor barrier film 24, in particular, a water vapor barrier film having a water vapor transmission rate of 1 × 10 ⁻² (g / (m ² · day)) or less is preferably used. By using such a water vapor barrier film 24, deterioration of the solar cell module 10 due to moisture can be prevented more reliably over a long period of time.

The water vapor barrier film 24 is obtained, for example, by forming a water vapor barrier layer 24b on a base material 24a. The water vapor barrier film 24 is disposed with the water vapor barrier layer 24 b facing the solar cell submodule 12.
For the base material 24b, for example, various resin films (plastic films) such as a PET film and a PEN film having a thickness of about 50 to 100 μm are used.
The water vapor barrier layer 24b is composed of, for example, an inorganic compound layer (hereinafter also referred to as an inorganic layer) that exhibits water vapor barrier properties (gas barrier properties).
In addition, in the water vapor barrier film 24, if necessary transparency can be ensured, various functions such as an adhesion layer, a flattening layer, an antireflection layer and the like are exhibited on at least one of the front surface and the back surface of the water vapor barrier film 24. One or more layers may be formed.

In the water vapor barrier film 24, 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.

  In addition, as the water vapor barrier film 24, for example, an organic compound layer (hereinafter also referred to as an organic layer) as an underlayer is formed on a substrate 24a of various resin films such as a PET film and a PEN film. The above-described inorganic layer may be formed on the layer. According to the water vapor barrier film 24 having such a configuration, 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 26 is for bonding the water vapor barrier film 24 and the surface protective layer 28. For example, the first adhesive filling layer 26 may be the same as the first adhesive filler 22 and the second adhesive filler 14. For this reason, detailed description is omitted. In the first adhesive filling layer 26, a thermoplastic polyurethane resin or the like is preferable.

  When the solar cell module 10 is installed outdoors, the surface protective layer 28 may come into contact with rain, hail, hail, snow, stones, etc., but the solar cell sub-module 12 can be protected from external forces, impacts, etc. applied from outside. It is something to protect. The surface protective layer 28 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 28 is composed of, for example, a plastic sheet, and from the above, transparency, weather resistance, heat resistance, flame resistance, water resistance, moisture resistance, wind pressure resistance, yield resistance, It must be excellent in chemical properties and other characteristics. The surface protective layer 28 is made of, for example, polycarbonate resin, acrylic resin or methacrylic resin, or a laminate thereof. In the surface protective layer 28, there are structural deterioration and yellowing due to UV light 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 28 in order to retain scratch resistance.
The thickness of the surface protective layer 28 (the thickness of the plastic sheet) is, for example, 0.5 to 2.5 mm, and preferably 1.0 to 2.0 mm.
When the thickness of the surface protective layer 28 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, if the thickness of the surface protective layer 28 exceeds 2.5 mm, the temperature distribution increases in the vertical direction during vacuum lamination, and the surface protective layer 28 may be warped. Further, it is desirable that the material is thin in view of material cost.

  Further, in order to enhance the heat resistance and flame retardancy of the solar cell module 10, flame retardant ETFE (tetrafluoroethylene / ethylene copolymer), PVDF (polyvinylidene fluoride) is applied to the surface 28 a of the surface protective layer 28. , PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene / hexafluoropropylene copolymer) or other fluorine-based transparent resin film may be used as a composite film. In this case, for example, the fluorinated transparent resin film is provided via an adhesive filling layer. In addition, a fluorine-based transparent resin film may be formed on the plastic sheet constituting the surface protective layer 28 by a coextrusion method or the like. In addition, the fluororesin film has a thickness of 20 to 500 μm, for example.

The peripheral seal 30 suppresses moisture intrusion from the peripheral edge of the solar cell module 10 and prevents a decrease in performance of the solar cell module 10. In particular, in the solar cell submodule 12 using CIS or CIGS or the like as the light absorption layer, the performance is easily deteriorated by moisture, but this can be suppressed.
The peripheral seal 30 contains an adsorbent. The peripheral seal 30 is made of an adhesive material, an adsorbent, a softening material, a vulcanized material, a deterioration preventing agent, a plasticizer, and the like.
Examples of the adhesive material include butyl rubber such as polyisobutylene and butyl rubber, and polyolefin.

As the adsorbent, for example, one that maintains a solid state after adsorption together with moisture adsorption ability is suitable, and a highly water-absorbing polymer, inorganic porous material, alkaline earth metal oxide, sulfate, etc. are used. it can.
Examples of the superabsorbent polymer include vinyl alcohol (CH ₂ CHOH), acrylic acid (CH ₂ CHOOH), sodium acrylate (CH ₂ COO—Na ⁺ ), potassium acrylate (CH ₂ COO—K ⁺ ), methacrylic acid. A polymer, a copolymer, a terpolymer, or the like using an acid (CH ₂ C (CH ₃ ) COOH) or sodium methacrylate (CH ₂ C (CH ₃ ) COO—Na ⁺ ) as a monomer is used.
Examples of the inorganic porous material include zeolite, silica gel, kaolin and the like. As the alkaline earth metal oxide, calcium oxide (CaO), barium oxide (BaO), magnesium oxide (MgO), strontium oxide (SrO), talc, or the like is used.
Examples of the sulfate include lithium sulfate (Li ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), and cobalt sulfate (CoSO ₄ ).

In the peripheral seal 30 containing these adsorbents, the water vapor transmission rate (WVTR) is desirably 0.01 (g / (m ² · day)) or less. Moreover, it is necessary as a highly reliable solar cell module that the adhesiveness with glass, a metal layer, and a plastic sheet is large, and the peripheral seal 30 has an adhesive strength by 90 ° peeling method of 0.5 N / mm or more. Is desirable.

Next, the solar cell submodule 12 of this embodiment will be described in detail with reference to FIG.
As shown in FIG. 2, 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 substrate 52 during the formation of the light absorption layer 34, and the like. 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 CIS film or 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. 2, 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. 2, the first conductive member 42 is, for example, a copper ribbon 42 a covered 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. Alternatively, the first conductive member 42 may be a conductive tape having an embossed structure formed by hot-plating In-Sn on a copper foil, and this conductive tape is connected by being bonded to the lower electrode 32 by pressure bonding with a roller. The

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 that of the first conductive member 42. For example, the copper ribbon 44a is coated with a coating material 44b of indium copper alloy. Similarly to 42, connection may be made by a conductive tape.

  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. Note that the arrows shown in FIG. 2 indicate the direction of current, and the direction of movement of electrons is opposite to the direction of current. For this reason, in the photoelectric conversion unit 48, the leftmost lower electrode 32 in FIG. 2 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 composed of, for example, ZnO to which Al, B, Ga, In, 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, a sputtering method, a CVD 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 an Ib group element, a IIIb group element, and a VIb group 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 perform like a battery.
Hereinafter, an example of the manufacturing method of the solar cell submodule 12 shown in FIG. 2 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. 2, the solar cell submodule 12 in which the plurality of solar cells 40 are electrically connected in series can be manufactured.

Here, schematic sectional views of conventional frameless solar cell submodules are shown in FIGS.
As shown in FIGS. 6 to 9, in the conventional frameless solar cell modules 100 to 100c, the solar cell submodule 110 is sealed with the first adhesive filler 102 and the second adhesive filler 104, A peripheral seal 112 is provided on the inside or outside of the surface protective layer 106 and the back surface protective layer 108 with the same size or a shape in which the back surface protective layer 108 is slightly smaller than the surface protective layer 106.
The surface protective layer 106 and the back surface protective layer 108 are basically composed of tempered glass, blue plate glass, or white plate glass. The peripheral seal 112 may be made of a rubber-based polymer containing an adsorbent, or the same material as the adhesive filling layer. However, in the frameless structure that does not use an aluminum frame and a filling sealant, it is directly outside. Exposed to the environment, the solar cell sub-module 110 is susceptible to performance degradation due to moisture like the CIS or CIGS thin film solar cell sub-module, and contains an adsorbent to maintain long-term reliability over 20 years It is necessary to have a peripheral seal.

  In the frameless solar cell modules 100a and 100b of FIG. 7 and FIG. 8, the reason why the back surface protective layer 108 is smaller than the surface protective layer 106 is to maintain the mechanical strength of the peripheral corner. In the solar cell module 100c of FIG. 9, when the peripheral seal 112 is disposed outside the surface protective layer 106 and the back surface protective layer 108, the mechanical strength is also weak, and when exposed to the external environment for a long time, peeling and weather resistance are caused. The structure is easy to be deteriorated due to deterioration, dirt, etc. Further, in the same sealing sheet and synthetic resin as the inner adhesive filling layer, moisture permeability WVTR> 1.0 is large, and moisture diffusion to the inside is remarkable.

  On the other hand, in the solar cell module 10 shown in FIG. 1A, glass is not used for the surface protective layer 28 as a moisture-proof measure for the solar cell submodule 12, and the water vapor barrier film 24 and the glass / glass are not used. The back sheet 16 is used for back surface protection other than the sandwich type frameless solar cell. Water vapor barrier film 24, back sheet 16, these base materials, 20-200 μm thick polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, fluororesin film such as polyvinyl fluoride (PVF), etc. Used, these organic layer films have a high moisture permeability WVTR of 1 to 60, and when the peripheral edge of these films is exposed to the outside environment, moisture diffusion from the peripheral edge to the inside along the substrate cross section. In the case of a solar cell sub-module, a water vapor barrier layer in a water vapor barrier film and an aluminum metal foil layer in a back sheet cannot prevent moisture diffused through these substrate cross sections. The performance will be degraded. For this reason, as a structure of a highly reliable solar cell module, it is important to seal the periphery of the organic layer film or the substrate with a sealing material.

As a countermeasure against the above-described moisture diffusion, when a plastic sheet is used as the surface protective layer 28 in order to reduce the weight of the solar cell module 10 of this embodiment shown in FIG. A water vapor barrier film 24, a first adhesive filler 22, a second adhesive filler 14, a back sheet 16, and a second adhesive filler layer 18, and a peripheral seal 30 is provided so as to surround them, and A peripheral edge between the front surface protective layer 28 and the back surface protective layer 20 made of a metal layer is filled with the peripheral seal 30. The peripheral seal 30 prevents moisture diffusion to the peripheral edge of the organic film and the cross section of the organic film.
Thus, in this embodiment, it becomes possible to suppress the internal diffusion of moisture through the organic layer described above, and high reliability can be maintained. Thereby, it is possible to realize a highly reliable frameless solar cell module 10 in particular considering moisture sealability.
Furthermore, a plastic sheet is used as the surface protective layer 28, so that the weight can be reduced. Furthermore, since no outer frame is provided, the cost can be reduced.

Next, a second embodiment will be described.
FIG. 3A is a schematic cross-sectional view showing the frameless solar cell module according to the second embodiment of the present invention, and FIG. 3B is a view before vacuum lamination of the frameless solar cell module of FIG. It is typical sectional drawing which shows the arrangement | positioning state of each member of.
In addition, in this embodiment, the same code | symbol is attached | subjected to the same structure as the frameless solar cell module 10 of 1st Embodiment shown to Fig.1 (a) and (b), and the detailed description is abbreviate | omitted. .

  In the frameless solar cell module 10a of the present embodiment shown in FIG. 3A (hereinafter simply referred to as the solar cell module 10a), the surface protective layer 28 is compared to the solar cell module 10 shown in FIG. In that the water vapor barrier film 24 is not provided, and the surface protective layer 28 is provided directly on the first adhesive filler 22, Since it is the structure similar to the solar cell module 10 of 1 embodiment, the detailed description is abbreviate | omitted.

  In the solar cell module 10a of the present embodiment, the surface protective layer 28 is made of blue plate glass, white plate glass, or glass mechanically reinforced by chemically treating the glass surface. The thickness of the blue plate glass or white plate glass constituting the surface protective layer 28 is, for example, 0.8 to 2.0 mm for weight reduction. When the thickness of the glass surface protective layer 28 is less than 0.8 mm, it is difficult to obtain a sufficient surface protection effect. On the other hand, if the glass surface protective layer 28 exceeds 2.0 mm, the effect of reducing the weight is difficult to obtain.

In the present embodiment, the first adhesive filler 22 is made of a sealing material made of an ionomer resin, and is made of a mixture with an ethylene / unsaturated carboxylic acid copolymer. Specifically, the product name High Milan-ES manufactured by Mitsui-Deupon Chemical Co. is a suitable material. The first adhesive filler 22 has a thickness of 100 to 1500 μm, and preferably has a thickness of 400 to 1000 μm.
Like the first adhesive filler 22, the second adhesive filler 14 and the second adhesive filler layer 18 other than the first adhesive filler 22 may be sealing materials made of an ionomer resin. Sealing materials such as EVA (ethylene vinyl acetate), PVB (polyvinyl butyral), PE (polyethylene), olefin-based adhesives and polyurethane-based adhesives can also be used.

In the solar cell module 10a, the first and second surfaces 28b of the front surface protective layer 28 and the front surface 20a of the rear surface protective layer 20 are in contact with each other and do not protrude from the outer edges of the front surface protective layer 28 and the rear surface protective layer 20. A peripheral seal 30 is provided outside the adhesive filler 22, the second adhesive filler 14, the back sheet 16 and the second adhesive filler layer 18 so as to surround them.
Thus, in the present embodiment, the peripheral seal is formed outside the peripheral edges of the first adhesive filler 22, the second adhesive filler 14, the solar cell submodule 12, the back sheet 16, and the second adhesive filler layer 18. 30, and the peripheral seal 30 fills the peripheral portion between the front surface protective layer 28 and the back surface protective layer 20. Thereby, the water | moisture-content spreading | diffusion to the periphery and cross-sectional part of each layer is blocked | prevented.

  In the present embodiment, when the surface protective layer 28 is made of glass, the water vapor barrier film 24 can be omitted as compared with a plastic sheet, and the configuration can be simplified. In the present embodiment, the same effect as in the first embodiment can be obtained. Also in the present embodiment, it is possible to realize a highly reliable frameless solar cell module 10a that is light in weight, low in cost, and particularly considering moisture sealability.

For example, the solar cell module 10a according to the present embodiment uses, for example, a vacuum laminator having lifting and lowering means, a buffer plate, and a heating means in a state where the respective members are stacked and arranged as shown in FIG. For example, the solar cell module 10a shown in FIG. 3A can be manufactured by vacuum lamination at a temperature of 130 to 150 ° C. under a total of 15 to 30 minutes of vacuum / press / hold.
Specifically, first, the peripheral seal 30 is pasted on the four sides of the peripheral surface of the back surface 28b of the surface protective layer 28 with the glass surface protective layer 28 facing down. Next, the first adhesive filler 22, the solar cell submodule 12, the second adhesive filler 14, the back sheet 16, and the second adhesive filler layer 18 are sequentially laminated inside the peripheral seal 30, and finally The back surface protective layer 20 is laminated so that the periphery is outside the periphery seal 30. That is, finally, the back surface protective layer 20 is laminated so that the outer periphery of the peripheral seal 30 and the periphery of the back surface protective layer 20 are aligned and overlapped. In this way, the stacked state shown in FIG. And it laminates with a vacuum laminator.
Next, for example, wiring (not shown) taken out on the back surface of the back surface protective layer 20 is soldered to an electrode of a connection box (not shown). Thereby, the solar cell module 10a shown to Fig.3 (a) is producible.

Next, a third embodiment will be described.
FIG. 4A is a schematic cross-sectional view showing a frameless solar cell module according to a third embodiment of the present invention, and FIG. 4B is a view before vacuum lamination of the frameless solar cell module of FIG. It is typical sectional drawing which shows the arrangement | positioning state of each member of.
In addition, in this embodiment, the same code | symbol is attached | subjected to the same structure as the frameless solar cell module 10 of 1st Embodiment shown to Fig.1 (a) and (b), and the detailed description is abbreviate | omitted. .

  In the frameless solar cell module 10b of the present embodiment shown in FIG. 4A (hereinafter simply referred to as the solar cell module 10b), the peripheral seal 30 is compared to the solar cell module 10 shown in FIG. The water vapor barrier film 24 is different in that the water vapor barrier film 24 is provided at the peripheral edge between the lower surface 25 of the water vapor barrier layer 24b and the front surface 20a of the back surface protective layer 20, and other configurations are the same as those of the first embodiment. Since it is the structure similar to the battery module 10, the detailed description is abbreviate | omitted.

  In the solar cell module 10b of the present embodiment, the surface protective layer 28 is formed of a plastic sheet, moisture diffusion from the surface and the periphery is blocked by the peripheral seal 30, and moisture from the periphery on the surface protective layer 28 side. Diffusion is blocked by the water vapor barrier layer 24. Also in this embodiment, the same effect as the solar cell module 10 of the first embodiment can be obtained.

  For example, the solar cell module 10b according to the present embodiment uses, for example, a vacuum laminator having lifting and lowering means, a buffer plate, and a heating means in a state where the respective members are stacked and arranged as shown in FIG. 4B. For example, the solar cell module 10b shown in FIG. 4A can be manufactured by vacuum lamination at a temperature of 130 to 150 ° C. under a total of 15 to 30 minutes of vacuum / press / hold.

Specifically, the first adhesive filling layer 26 and the water vapor barrier film 24 are laminated with the surface protective layer 28 facing down. At this time, the water vapor barrier film 24 uses the surface protective layer 28 side as the base material 24a.
Next, the peripheral seal | sticker 30 is affixed on the water vapor | steam barrier layer 24b of the water vapor | steam barrier film 24, and four sides of a periphery. Next, the first adhesive filler 22, the solar cell submodule 12, the second adhesive filler 14, the back sheet 16, and the second adhesive filler layer 18 are laminated on the inner side of the peripheral seal 30, and finally The back surface protective layer 20 is laminated so that the outer periphery of the peripheral seal 30 and the periphery of the back surface protective layer 20 coincide and overlap. In this way, the stacked state shown in FIG. And it laminates with a vacuum laminator.
Next, for example, wiring (not shown) taken out on the back surface of the back surface protective layer 20 is soldered to an electrode of a connection box (not shown). Thereby, the solar cell module 10b shown to Fig.4 (a) is producible.

  In this embodiment, it can be set as the laminated body α of the water vapor barrier film 24, the first adhesive filling layer 26, and the surface protective layer 28. For this reason, when the solar cell module 10b is formed, the laminate α is formed, and by laminating the members, the lamination of the members can be facilitated, and the laminating process can be simplified.

  Also in the present embodiment, similarly to the first embodiment, the above-described fluorine-based transparent resin film is laminated on the surface 28a of the surface protective layer 28, and in this state, vacuum lamination is performed, An electric battery module can also be produced.

  The present invention is basically configured as described above. The frameless solar cell module of the present invention has been described in detail above. However, the present invention is not limited to the above-described embodiment, and various improvements or modifications may be made without departing from the spirit of the present invention. Of course.

Hereinafter, the frameless solar cell module of the present invention will be described more specifically.
In this example, the frameless solar cell modules of Examples 1 to 3 and Comparative Example 1 shown below were produced and their performance was evaluated.

Example 1
A solar cell module 10 having a substrate structure and including a solar cell submodule 12 using a CIGS film as a light absorption layer was manufactured as shown in FIG.
In Example 1, a three-layer composite plastic of FEP (thickness 100 μm), EVA, polycarbonate (manufactured by Mitsubishi Gas Chemical, with UV absorption layer, sun guard sheet product name L55, thickness 1.0 mm) on the surface protective layer 28 A sheet was used.
The water vapor barrier film 24 has a water vapor permeability (WVTR) of 10 ⁻⁴ to 10 ⁻ in which an organic film and an Al ₂ O ₃ inorganic film are laminated as a water vapor barrier layer 24b on a 100 μm thick PET film (base material 24a). The thing of the performance of ⁵ g / (m < ² > * day) was used.
The solar cell submodule 12 was a flexible CIGS integrated thin film solar cell submodule using an anodized SUS-AL substrate (aluminum-stainless steel clad substrate).
The back sheet 16 was a PVF / AL foil / PVF sheet manufactured by Mitsubishi Aluminum Package. For the back protective layer 20, a galvalume steel plate having a thickness of 0.4 mm was used.
Moreover, an EVA adhesive sheet having a thickness of 400 μm was used for the first adhesive filler 22, the second adhesive filler 14, and the second adhesive filler layer 18. As the first adhesive filling layer 26, a 300 μm thick thermoplastic polyurethane adhesive sheet (Estane PV1000 manufactured by Lubrizol) was used.
A hot melt type sealing material containing a hygroscopic agent is used for the peripheral seal 30, and the peripheral seal 30 has a thickness of 1.0 mm and a width of 10 mm. The sealing material is Helio Seal PVS101 (product name) manufactured by ADCO.

As a production procedure of Example 1, a three-layer composite plastic sheet of the surface protective layer 28 is produced in advance by a thermocompression bonding method, and a laminated member is laid up.
First, the peripheral seal 30 is pasted on the four sides of the peripheral edge of the back surface 28b of the surface protective layer 28 with the surface protective layer 28 facing down. Next, the first adhesive filling layer 26 (300 μm-thick thermoplastic polyurethane adhesive sheet), the water vapor barrier film 24, the first adhesive filler 22 (400 μm-thick EVA adhesive sheet), the sun, and the inner side of the peripheral seal 30 The battery sub-module 12, the second adhesive filler 14 (400 μm thick EVA adhesive sheet), the back sheet 16, and the second adhesive filler layer 18 (400 μm thick EVA adhesive sheet) are laminated, and finally the peripheral edge is a peripheral seal. 30 A back surface protective layer 20 (galvalume steel plate) was laminated so as to be on the outside. That is, finally, the back surface protective layer 20 is laminated so that the outer periphery of the peripheral seal 30 and the periphery of the back surface protective layer 20 are aligned and overlapped. Here, since the number of laminated layers is large, it was temporarily fixed with a Kapton tape so as not to cause a gap between the layers.
In addition, the water vapor | steam barrier film 24 was arrange | positioned so that the water vapor | steam barrier layer 24b might become the solar cell submodule 12 side.
Then, laminating with a vacuum laminator at a temperature of 140 ° C. under a lamination condition of 20 minutes in total of 5 minutes in vacuum, 10 minutes in press, and 5 minutes in hold, and the wiring taken out on the back surface of the back surface protective layer 20 is soldered to the electrode of the connection box Thus, a solar cell module 10 was produced.

(Example 2)
A solar cell module 10a shown in FIG. 3A including a solar cell submodule 12 having a substrate structure and using a CIGS film as a light absorption layer was produced.
As the surface protective layer 28, blue plate glass having a thickness of 1.0 mm was used.
As the first adhesive filler 22 and the second adhesive filler 14, Himiran-ES-7046 (product name) made by Mitsui-Deupon Chemical Co., which is an ionomer resin, was used. The thicknesses of the first adhesive filler 22 and the second adhesive filler 14 were 400 μm.
An EVA adhesive sheet having a thickness of 400 μm was used for the second adhesive filling layer 18.
The back sheet 16 was a PVF / AL foil / PVF sheet manufactured by Mitsubishi Aluminum Package. As the back surface protective layer, a 1.0 mm thick aluminum plate subjected to single-side alumite treatment was used.
A hot melt type sealing material containing a hygroscopic agent is used for the peripheral seal 30, and the peripheral seal 30 has a thickness of 1.0 mm and a width of 10 mm. The sealing material is Helio Seal PVS101 (product name) manufactured by ADCO.

As a manufacturing procedure of Example 2, first, the peripheral seal 30 is pasted on the four sides of the peripheral surface of the back surface 28b of the surface protective layer 28 with the surface protective layer 28 first.
Next, the first adhesive filler 22 (Himira-ES-7046 (product name) having a thickness of 400 μm), the solar cell sub-module 12, and the second adhesive filler 14 (thickness) are provided on the inner side of the peripheral seal. 400 μm High Milan-ES-7046 (product name)), back sheet 16, second adhesive filling layer 18 (400 μm thick EVA adhesive sheet) are laminated in order, and finally the peripheral edge is outside the peripheral seal 30. Thus, the back surface protection layer 20 (the aluminum plate which carried out the single-sided alumite process) was laminated | stacked. That is, finally, the back surface protective layer 20 is laminated so that the outer periphery of the peripheral seal 30 and the periphery of the back surface protective layer 20 are aligned and overlapped. Then, laminating with a vacuum laminator at a temperature of 150 ° C. under a lamination condition of 20 minutes in total of vacuum 5 minutes, press 10 minutes, holding 5 minutes, and solder the wiring taken out on the back surface of the back surface protective layer 20 to the electrodes of the connection box Thus, a solar cell module 10a was produced.

(Example 3)
A solar cell module 10b shown in FIG. 4A including a solar cell submodule 12 having a substrate structure and using a CIGS film as a light absorption layer was produced.
In Example 3, as compared with Example 1 described above, the surface protective layer 28, the first adhesive filling layer 26, and the water vapor barrier film 24 have the same size and the periphery is exposed to the outside environment. Yes. However, since the water vapor barrier layer 24b formed on one surface of the water vapor barrier film 24 is on the solar cell submodule 12 side, moisture intrusion from the outside is prevented. Since the other configuration is the same as that of the first embodiment, detailed description thereof is omitted.

  In Example 3, as a production procedure, the surface protective layer 28 is placed below and sequentially laminated, except that the peripheral seal 30 is attached to the water vapor barrier layer 24b of the water vapor barrier film 24, and other than that, A solar cell module 10b was produced in the same procedure as in Example 1.

(Comparative Example 1)
A solar cell module 120 shown in FIG. 5 including the solar cell submodule 12 having a substrate structure and using a CIGS film as a light absorption layer was produced.
Comparative Example 1 (solar cell module 120 shown in FIG. 5) is different from the above-described Example 1 (solar cell module 10 shown in FIG. 1A) in the back sheet 16, the second adhesive filling layer 18 and The configuration is the same as that of Example 1 described above except that the periphery of the back surface protective layer 20 is exposed to the outside environment.
A peripheral seal 30 is provided between the back surface 28b of the surface protective layer 28 and the surface 16a of the back sheet 16, and the first adhesive filling layer 26, the water vapor barrier film 24, the first adhesive filling material 22, the solar cell submodule 12, and It is arranged on the periphery of the second adhesive filler 14.
A PVF / AL foil / PVF sheet (manufactured by Mitsubishi Aluminum Package) is used for the backsheet 18. For this reason, there is a PVF layer (organic layer) on the solar cell module 12 side from the structure of the back sheet 18, and moisture enters inside through the PVF layer from the periphery.
In Comparative Example 1, the members used are the same as in Example 1 except for those described above. For this reason, the detailed description is abbreviate | omitted.

In Comparative Example 1, as a preparation procedure, a three-layer composite plastic sheet of the surface protective layer 28 is prepared in advance by a thermocompression bonding method, and a laminated member is laid up.
First, the peripheral seal 30 is pasted on the four sides of the periphery first with the surface protective layer 28 facing down. Next, the first adhesive filling layer 26 (400 μm thick EVA adhesive sheet), the water vapor barrier film 24, the first adhesive filler 22 (400 μm thick EVA adhesive sheet), and the solar cell sub are provided inside the peripheral seal 30. The module 12 and the second adhesive filler 14 (400 μm thick EVA adhesive sheet) are laminated. In addition, the water vapor | steam barrier film 24 was arrange | positioned so that the water vapor | steam barrier layer 24b might become the solar cell submodule 12 side.
Next, the back sheet 16, the second adhesive filling layer 18 (400 μm thick EVA adhesive sheet), and the back surface protective layer 20 (galvalume steel plate) were laminated so that the peripheral edge was outside the peripheral seal 30. Here, since the number of laminated layers is large, it was temporarily fixed with a Kapton tape so as not to cause a gap between the layers.
In this laminated state, lamination was performed under the same lamination conditions as in Example 1, and the wiring taken out on the back surface of the back surface protective layer 20 was soldered to the electrode of the connection box to produce a solar cell module 120.

In order to evaluate the performance deterioration due to moisture intrusion of the solar cell modules manufactured as described above in Examples 1 to 3 and Comparative Example 1 in total, the high temperature and high humidity test was performed under the conditions of a temperature of 85 ° C. and a humidity of 85% RH. Was performed for 2000 hours, and then the photoelectric conversion efficiency was measured by IV measurement under light irradiation. The results are shown in Table 1 below.
Here, the photoelectric conversion efficiency was calculated by irradiating each solar cell module of Examples 1 to 3 and Comparative Example 1 with 100 mW / cm ² of light using an AM1.5 solar simulator and performing IV measurement. is there.

As shown in Table 1, the reduction in conversion efficiency with respect to the initial value is 2 to 6 due to the sealing structure by the peripheral seals of Examples 1 to 3 with respect to Comparative Example 1 in which the peripheral seal does not cover the peripheral edge of the backsheet. % And within 10%. On the other hand, in Comparative Example 1, the decrease rate was 10%.
As the conversion efficiency deteriorates, the series resistance Rs increases, and the fill factor F.R. F. This is thought to be because the sheet resistance of the transparent electrode layer of the CIGS integrated solar cell submodule was increased due to moisture intrusion. From the above results, the effects of the present invention are clear.

10, 10a, 10b Solar cell module 12 Solar cell sub-module 14 Second adhesive filler 16 Back sheet 18 Second adhesive filler layer 20 Back surface protective layer 22 First adhesive filler 24 Water vapor barrier film 24a Base material 24b Water vapor Barrier layer 26 First adhesive filling layer 28 Surface protective layer 30 Perimeter seal 40 Solar cell 50 Substrate

Claims (6)

A frameless solar cell module in which a surface protection layer is provided on the front surface side of the solar cell submodule sealed with an adhesive filler, and a back surface protection layer is provided on the back surface side of the solar cell submodule,
A back sheet is provided between the back protective layer and the adhesive filler,
A frameless solar cell module characterized in that a peripheral seal made of a sealing material containing an adsorbent is provided inside the surface protective layer and the back surface protective layer, and outside the adhesive filler and the back sheet. . A water vapor barrier film is provided between the surface protective layer and the adhesive filler,
The frameless solar cell module according to claim 1, wherein the peripheral seal is provided outside the adhesive filler, the water vapor barrier film, and the back sheet. A frameless solar cell module in which a surface protective layer made of a plastic sheet is provided on the surface side of the solar cell submodule sealed with an adhesive filler, and a back surface protective layer is provided on the back side of the solar cell submodule. And
A water vapor barrier film is provided between the surface protective layer and the adhesive filler, and a back sheet is provided between the back surface protective layer and the adhesive filler,
A peripheral seal made of a sealing material containing an adsorbent is provided inside the laminate of the surface protective layer and the water vapor barrier film and the back protective layer, and outside the adhesive filler and the back sheet. A frameless solar cell module.   3. The frameless solar cell module according to claim 1, wherein the surface protective layer is made of a plastic sheet, or blue plate glass or white plate glass having a thickness of 0.8 to 2.0 mm.   The frameless solar cell module according to any one of claims 1 to 4, wherein the back surface protective layer is formed of a metal sheet.   The frameless solar cell module according to any one of claims 1 to 5, wherein the solar cell submodule has a light absorption layer formed of a CIS film or a CIGS film.

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