JP2000216422A - Photovoltaic element module and building material using the photovoltaic element module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain constitution of a photovoltaic element module excellent in resistance to corrosion. SOLUTION: This photovoltaic element module is constituted by sealing a photovoltaic element 101 with which one or more bypass diodes 102 are connected, with one or more kinds of sealing material 105. At least the sealing material 105 which is formed to be in contact with the bypass diodes 102 is composed of resin wherein the content of constituent which generates acid by hydrolysis or pyrolysis is made less than or equal 20%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic element module, and more particularly to a photovoltaic element module having improved corrosion resistance and a building material using the photovoltaic element module.

[0002]

In recent years, it is expected to global warming due to the influence of the greenhouse effect due to an increase in CO ₂ occurs, clean energy requirements that do not emit CO ₂ is increasingly. As an energy source that does not emit CO ₂ , there is nuclear power generation, but the problem of radioactive waste has not been solved, and clean energy with higher safety is desired. Under such circumstances, among the clean energies, solar cells, in particular, have attracted much attention because of their cleanliness, safety, and ease of handling. In particular, there is a great expectation for a method of installing it on a roof or wall of a house or a soundproof wall of a highway and using it as a power source.

As conventional solar cells, various types of solar cells such as crystalline solar cells, amorphous solar cells, and compound semiconductor solar cells have been researched and developed. Among these, amorphous silicon solar cells have conversion efficiencies that are not comparable to crystalline solar cells, but crystalline silicon solar cells do not have such features as easy area enlargement, large light absorption coefficient, and operation in thin films. Has excellent features,
It is one of the promising solar cells.

FIG. 2 is a schematic view of a conventional solar cell module.

FIG. 2A is a schematic view of a solar cell module, and FIG. 2B is a schematic view of the solar cell module viewed from a cross-sectional direction.

In FIG. 2, 201, 201 'are solar cell elements (photovoltaic elements), 202 is a bus bar electrode, and 203, 2
03 'is an insulating member, 204 is a metal body, 205 is a current collecting electrode, and 206 is a brazing material such as solder.

FIG. 2A shows a conventional solar cell module.
As shown in FIG. 7, resin sealing is performed between the surface coating material and the back surface coating material, and the solar cell elements 201 and 201 ′ are electrically connected to each other by the solder 206 via the metal member 204.

[0008] These solar cell element modules are shown in FIG.
As shown in (b), the front member 207 and the back member 210
, And a surface sealing material 208 and a back surface sealing material 209 are interposed to bond and seal each other.

As the front surface member 207, a light transmitting glass plate or a fluorine-based film is often used, and as the rear surface member 208, a metal steel plate, a metal seed, a resin film, or the like is often used. Also, the surface sealing material 208
In addition, the back surface sealing material 209 is required to have characteristics such as transparency, weather resistance, and high adhesiveness.
(Ethylene-vinyl acetate copolymer: vinyl acetate content 20 to
30 wt%) is commonly used.

[0010] In addition, in order to ensure insulation between the solar cell module and the back surface member 208, an insulating film such as PET may be provided in the back surface sealing material 209. Such a configuration is disclosed in, for example, JP-A-9-55525.

[0011]

By the way, in many cases, a bypass diode is connected to a solar cell module in order to prevent the destruction of the cell and the decrease in output that occur when a part of the solar cell module is shaded. Can be As such a bypass diode, many systems using bare chip diodes have been disclosed in order to make the entire solar cell module thin.

However, the solar cell module to which such a bypass diode is connected has the following problems when combined with the above-described conventional sealing material.

First, since solar cells are usually installed outdoors, they are susceptible to the climate of the area, and are exposed to a very severe environment, especially in a humid area or an area where the temperature difference between day and night is large. Become. In such an environment,
When the above-mentioned conventional EVA resin is used, usually,
There is almost no barrier to moisture, and the permeability of moisture and water vapor is high. As a result, moisture reaches the bypass diode, and various members used in the bypass diode are corroded. In particular, when the EVA is in direct contact with the bypass diode, moisture easily reaches the bypass diode itself, and corrosion is most severe.

Further, among the members of the bypass diode, the brazing material is most easily corroded, and as a result, the brazing material becomes brittle. Furthermore, among the brazing materials, when a high-temperature solder having a high lead content is used, the higher the lead content, the more remarkable the corrosion, and in the worst case, an OPEN failure may occur. .

Second, when the EVA resin is in contact with the bypass diode, there is a factor that further speeds up the progress of corrosion. That is, acetic acid residues contained in the EVA resin are hydrolyzed in the presence of water to release acetic acid. The released acetic acid easily comes into contact with the bypass diode, and when acetic acid comes into contact with various members (particularly brazing material) of the bypass diode, corrosion becomes more severe than that pointed out in the first problem described above. Failure life is shortened.

As described above, a study on the peculiar problem in the case of using EVA as the filler is described in, for example,
No. 7-302926. That is,
JP-A-07-302926 discloses a technique in which a copolymer resin of ethylene and an unsaturated fatty acid ester is arranged at least on the light incident surface side of a photovoltaic element.

However, the above publication does not mention at all the corrosion of the bypass diode. Also,
In the above publication, only the acetic acid released from EVA is mentioned, and no consideration is given to other acids released from the resin. Furthermore, the technology disclosed in the above publication is limited to ethylene-based copolymer resins, and is not a study of a material having good anticorrosion properties over the entire resin.

From the above points, the photovoltaic element module according to the present invention and the building material using the photovoltaic element module have completely different purposes and configurations from the technology disclosed in the above publication. It is.

An object of the present invention is to solve the above-mentioned problems of the conventional technology and to provide a configuration of a photovoltaic element module having excellent corrosion resistance. More specifically, an object of the present invention is to propose a resin that contacts a bypass diode.

Another object of the present invention is to provide a building material incorporating such a photovoltaic element module.

[0021]

Means for Solving the Problems As a result of intensive research and development for solving the above problems, the present inventor has found that the following photovoltaic element module is the best.

That is, a photovoltaic element module according to the present invention is a photovoltaic element module in which a photovoltaic element to which one or more bypass diodes are connected is sealed with one or more kinds of sealing materials. At least a sealing material provided in contact with the bypass diode is made of a resin having a content of a component that generates an acid by hydrolysis or thermal decomposition of 20% or less. is there.

With such a configuration, the resin that directly contacts the bypass diode is a resin that does not generate an acid or a resin that generates a small amount of acid even if an acid is generated. The corrosion rate of the member can be reduced. At the same time, the most corrosive brazing material can be protected. In particular, when the content of the component serving as the acid source is 20% or less, the corrosion rate is drastically reduced.

Further, the resin is preferably a copolymer resin of ethylene and an unsaturated fatty acid ester.

By adopting such a structure, the anticorrosion function can be enhanced, and high transparency, weather resistance, adhesion, and other properties required as a sealing material for the photovoltaic element can be obtained.
Heat resistance and low water absorption can be satisfied. Particularly important is that the copolymer resin of ethylene and unsaturated fatty acid ester is more excellent in moisture permeability and low water absorption than EVA,
Moisture hardly reaches the bypass diode part, moisture proof,
It is excellent in corrosion resistance.

Further, it is preferable that the unsaturated fatty acid ester is ethyl acrylate or methyl acrylate.

By adopting such a configuration, economical efficiency such as low cost can be satisfied, and practical availability is high, such as easy availability of materials.

Preferably, the photovoltaic element module is formed on a reinforcing plate.

With such a configuration, the direction in which moisture and corrosive components enter is limited, and the moisture resistance and corrosion resistance can be further improved.

Further, a building material can be constructed by integrally forming the photovoltaic device module or the photovoltaic device module with the reinforcing plate and the building material main body.

With this configuration, the photovoltaic element module can be easily installed outdoors. In addition, a highly reliable photovoltaic element module can be provided even under severe environmental conditions such as acid rain and salt-affected areas.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a photovoltaic element module according to the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic view showing an example of the photovoltaic element module of the present invention, and FIG. 3 is a schematic view showing another example of the photovoltaic element module of the present invention.

In FIG. 1, 101 is a photovoltaic element, 102 is a bypass diode, 103 is a surface member, 104 is a surface sealing material, 105 is a sealing material, 106 is a back surface sealing material, 107
Denotes a back surface insulating material, and 108 denotes a reinforcing plate. Also,
In FIG. 1, the upper direction is the light incident side.

In FIG. 3, reference numeral 301 denotes a photovoltaic element;
02 is a bypass diode, 303 is a reinforcing plate having the function of a surface member, 304 is a surface sealing material, 305 is a sealing material, 306 is a back surface sealing material, and 307 is a back surface insulating material. In FIG. 3, the upper direction is the light incident side.

In the photovoltaic element module of the present invention, the sealing material for sealing the photovoltaic elements 101 and 301 means the sealing materials 105 and 305.

The above members will be described below. In addition,
The description of the members and the like will be made with reference to FIG. 1 unless otherwise required.

<Photovoltaic Element> An object of the present invention is to provide a bypass diode 10 connected to a photovoltaic element 101.
2, the type of the photovoltaic element 101 used in the photovoltaic element module according to the present invention is not particularly limited, and is single crystal, thin film single crystal, polycrystal, thin film polycrystal. Alternatively, in addition to being applicable to amorphous silicon solar cells, the present invention is also applicable to solar cells using semiconductors other than silicon and Schottky junction type solar cells.

<Bypass Diode> The bypass diode 102 of the present invention has a function of preventing the output of the photovoltaic element 101 from decreasing or being destroyed. The type of the diode 102 can be used without any particular limitation. The present invention relates to a brazing material (solder) mainly used for a semiconductor chip portion of the bypass diode 102 and a metal electrode interface.
This is very effective especially for the by-pass diode 102 having a moldless portion in which the solder portion is exposed, since the effect is very effective for the corrosion of the metal.

In the embodiment shown in FIG. 1, the bypass diode 102 is installed on the non-light-receiving surface side of the photovoltaic element 101, but the installation position of the bypass diode 102 is not particularly limited. It may be installed in such as.

Further, the number of bypass diodes 102 is not limited, and a plurality of bypass diodes 102 may be connected to one photovoltaic element 101 or one photovoltaic element 101 may be connected to one photovoltaic element 101. The bypass diode 102 may be connected.

<Sealing Material> A sealing material 105 for sealing the photovoltaic element 101 is a resin provided in contact with the bypass diode 102, and also includes a front surface sealing material 104 and a back surface sealing. Material 106 and bypass diode 10
2 is also a resin for avoiding contact.

Therefore, in the embodiment shown in FIG. 1, the sealing material 105 is provided on the non-light receiving surface side, but may be provided on the light receiving surface side, for example, depending on the installation position of the bypass diode 102. Alternatively, it may be arranged so as to surround the bypass diode 102.

The size of the sealing material 105 needs to be such that it can be selectively disposed at least in a portion where the bypass diode 102 exists. However, in order to simplify the process, it is more preferable that the size of the sealing material 105 is substantially the same as that of the other sealing materials 105.
In this case, the back surface sealing material 106 does not need to be particularly provided.

The properties of the sealing material 105 are as follows: the content of a component that generates an acid by hydrolysis or thermal decomposition is 2%.
It is necessary that the content be 0 wt% or less. Here, the component that generates an acid is a monomer or an oligomer that may generate an acid by hydrolysis or thermal decomposition, and typical examples of the acid include acetic acid and acrylic acid. For example, in the case of an EVA resin, a vinyl acetate monomer corresponds as a constituent component, and acetic acid is easily formed by a hydrolysis action. In the case of a resin having an acrylic acid monomer in the main chain, acrylic acid is generated by cutting off the end of the main chain.

If the content of such an acid-generating component exceeds 20% by weight, the degree of corrosion becomes severe and the life of the members of the photovoltaic element becomes extremely short. 20w content of acid-generating component
It is necessary to be less than t%.

Further, the sealing material 105 is used for protecting the photovoltaic element 1 from severe external environment such as temperature change, humidity change and impact.
01 is required to have weather resistance, high adhesion, heat resistance, cold resistance, and impact resistance. In addition to the above, the sealing material 105
Is located on the light incident side, high transparency is required.

As a specific example for satisfying these requirements, for example, the content of an acid generating component is 20 wt%.
The following ethylene-vinyl acetate copolymer (EVA),
Ethylene-unsaturated fatty acid copolymer (EEA, EMA, E
BA, EMM, EEM, etc.), polyolefin-based resins such as butyral resin, urethane resin, silicone resin and the like are used as suitable materials. Note that the sealing material 105
Is not limited to these resins, and any resin that satisfies the above requirements can be used.

Further, among these resins, a copolymer resin of ethylene and an unsaturated fatty acid ester having a high waterproof and moisture-proof function with respect to the permeability of moisture and water vapor is preferable. In the case of a copolymer resin of ethylene and an unsaturated fatty acid ester,
Since the acid that may be generated is a very weak acid, the degree of corrosion is extremely reduced, and the anticorrosion function can be further enhanced.

Among these ethylene and unsaturated fatty acid ester copolymers, EMA and EEA are preferable from the viewpoint of availability and economy, and EE and EEA are more preferable from the viewpoint of transparency.
A is most preferred.

Crosslinking is effective for improving the hardness and heat resistance of these resins. The method of crosslinking is not particularly limited, but a method of adding an organic peroxide to a resin in advance and heating the resin is preferred. The organic peroxide is not particularly limited as long as it has high crosslinking efficiency of the resin and has no adverse effect on weather resistance.

Further, additives such as an ultraviolet ray inhibitor, a light stabilizer and a secondary antioxidant may be added to improve the weather resistance, or a coupling agent to improve the adhesive strength may be added. May be.

<Surface Sealing Material> The surface sealing material 104 is required to have high transparency, weather resistance, high adhesion, heat resistance, cold resistance, and impact resistance, and is basically the same as the sealing material 105. Materials can be used.

Since the surface sealing material 104 does not directly contact the bypass diode 102, there is no regulation on the generation of acid, and any material satisfying the above characteristics can be used as appropriate. When the sealing material 105 is provided on the surface, it is not necessary to particularly provide the surface sealing material 104.

<Back Sealing Material> Since the back sealing material 106 is provided on the non-light receiving surface side, transparency is not required. Further, as other characteristics, the surface sealing material 104
It is possible to use exactly the same material as. It is not necessary to use exactly the same material as the front surface sealing material 104 as the back surface sealing material 106, and there is no particular limitation.

<Surface Member> Since the surface member 103 is located on the outermost layer of the solar cell module, it has long-term reliability in outdoor exposure of the solar cell module, including weather resistance, water repellency, stain resistance, and mechanical strength. Performance is required to ensure

As a material preferably used for the surface member 103, an ethylene tetrafluoride-ethylene copolymer (ETF)
E), polyvinyl fluoride resin (PVF), polyvinylidene fluoride resin (PVDF), polytetrafluoroethylene resin (TFE), ethylene tetrafluoride-propylene hexafluoride copolymer (FEP), polytrifluorinated chloride Ethylene resin (C
TFE). From the viewpoint of weather resistance, polyvinylidene fluoride resin is excellent, but ethylene tetrafluoride-ethylene copolymer is excellent in terms of both weather resistance and mechanical strength.

In order to improve the adhesion of the surface sealing material 104 to the resin, the surface member 103 is preferably subjected to a corona treatment or a plasma treatment. It is also possible to use a film in which the surface member 103 has been subjected to a stretching treatment in order to improve the mechanical strength.

Further, as the surface member 103, a known glass plate can be used as the solar cell module. In this case, a reinforcing plate 10 described later is used.
8 also serves as the function.

<Back Insulator> The back insulator 107 is necessary for maintaining electrical insulation between the photovoltaic element module and the outside. As a material of the back surface insulator 107, a material that can secure sufficient electric insulation with the photovoltaic element module, has excellent long-term durability, can withstand thermal expansion and thermal contraction, that is, has flexibility is preferable. As the back insulator 107 preferably used, a film made of nylon or polyethylene terephthalate can be used.

<Reinforcing Plate> The reinforcing plate 108 needs to have a function of completely blocking the permeation of moisture and water vapor, and further has a function of increasing the rigidity of the photovoltaic element module. preferable. Considering the permeability of water vapor, a material using a metal or a glass plate is preferable. For example, a metal foil, a metal steel plate, and a glass plate are preferable.

When the reinforcing plate 108 is formed, the permeation of water from the formed side can be reduced to zero.
The direction of entry of moisture is restricted, and the corrosion life of the photovoltaic element module can be extended.

In the embodiment shown in FIG. 1, the photovoltaic element 1
1 shows an example in which a reinforcing plate 108 is formed on the non-light receiving surface side of No. 01. In this case, as the reinforcing plate 108, a metal laminated film, a metal steel plate, a glass plate, or the like can be used. Further, as the metal steel plate, for example, a stainless steel plate, a plated steel plate, a galvalume steel plate and the like can be used,
It is not limited to this.

The embodiment shown in FIG. 3 shows an example in which a reinforcing plate 303 having the function of a surface member is formed on the light receiving surface side of the photovoltaic element 301. In this case, since the reinforcing plate 303 also serves as a surface member, its physical properties require transparency, and a glass plate is optimal.

<Building Materials> As described above, the photovoltaic element module of the present invention has a structure that is extremely strong against corrosion. Has sufficient durability against external factors that affect the

Therefore, the photovoltaic element module of the present invention can be used as a form bonded to a roof or a form installed on a roof. The metal steel plate can be used as it is as a metal roof for a house roof. in this case,
There is no problem in bending metal steel sheet into a structure suitable for roof installation.

FIG. 4 shows an example of a building material according to the present invention, in which (a) is applied to a horizontal roofing material, (b) is applied to a tiled roofing material, and (c) is applied to a flat roofing material.

In the examples shown in FIGS. 4A, 4B and 4C, the building material 400 provided with each photovoltaic element module is:
It is fixed to the installation surface (roof surface) by the fixing member 401. Furthermore, in order to improve the workability on the roof, the photovoltaic element module, the roof member (rafters, a field board, etc.), the heat insulating material and the like may be integrated. The building material 400 of the present invention
In addition to the roof material, a module integrated with various building materials such as wall materials can be configured.

[0069]

The photovoltaic element module according to the present invention will now be described in more detail with reference to specific examples.

<Example 1> First, a procedure for producing an amorphous solar cell module using the photovoltaic element module according to Example 1 will be described with reference to FIG.

FIG. 5 is a schematic view showing the appearance of the photovoltaic element module according to Embodiment 1 of the present invention, and FIG.
Is a plan view of the photovoltaic element module viewed from the light receiving surface side,
FIG. 5B is a plan view of the case where the photovoltaic element modules are connected in series as viewed from the light receiving surface side, and FIG.
FIG. 6 is a sectional view taken along the line XX ′ in FIG.

In FIG. 5A, reference numeral 500 denotes a 300 mm × 280 mm photovoltaic element including a substrate, a lower electrode layer, amorphous silicon having a photovoltaic function, and an upper electrode layer. The substrate is a stainless steel plate having a thickness of 150 μm, and a lower electrode layer is formed immediately above the substrate by sequentially depositing Al and ZnO to a thickness of several thousand そ れ ぞ れ by sputtering. Amorphous silicon is n-type, i-type, p-type, n-type, i-type, p-type,
It is formed by sequentially depositing n-type, i-type, and p-type layers. The upper electrode layer was a transparent electrode film, and In was deposited by a resistance heating method in an O ₂ atmosphere to form an indium oxide thin film having a thickness of about 700 °.

Next, the photovoltaic element 50 thus prepared
On the other hand, in order to prevent the adverse effect of the short circuit between the substrate and the transparent electrode film generated when the outer periphery of the photovoltaic element 500 is cut off from affecting the effective light receiving range, FeC
By applying an etching paste containing l ₃ , AlCl _3, etc. by a screen printing method, and washing after heating,
A part of the transparent electrode film of the photovoltaic element 500 was linearly removed to form an etching line 501.

Thereafter, one side of the back-side edge of the photovoltaic element 500 has a width of 7.5 m as a back-side power extraction member.
m, length 285 mm, thickness 100 μm, soft copper foil 503
Was connected to a conductive substrate by a laser welding method.

Thereafter, a width of 7.5 m is set on one side of the light receiving surface opposite to the back side conductive foil at the end of the photovoltaic element 500.
m, a length of 280 mm, and a thickness of 200 μm of a polyimide base insulating tape 504 were applied. At this time, the insulating tape 504
Was attached so as to slightly protrude so as to cover the edge of the right side of the photovoltaic element 500.

Thereafter, the carbon paste was previously coated with φ100
A carbon coated wire coated on a μm copper wire was formed on the photovoltaic element 500 and the insulating adhesive tape 504 at a pitch of 5.6 mm to form a current collecting electrode 505.

Further, on the insulating adhesive tape 504,
A bus bar electrode 506, which is a further current collecting electrode of the current collecting electrode 505, was formed. This busbar electrode 506 has a width of 5 m.
m, a length of 285 mm, a thickness of 100 μm, and a silver-plated copper foil placed on an insulating tape at 200 ° C., 3 kg /
Under the conditions of cm ² and 180 seconds, the wire electrode is fixed by heating and pressing simultaneously. At this time, as shown in FIG. 5A, one side of a silver-plated copper foil (buzz bar electrode) 506 was extended outward from the photovoltaic element 500.

Next, a silver-plated copper foil (bus bar electrode) 50
A transparent PET tape 507 having a thickness of 7 mm square and a thickness of 130 μm was attached to a part of the portion on the surface 6 that protruded from the photovoltaic element 500.

The photovoltaic element 5 thus manufactured
FIGS. 5 (b) and 5 (c) show an example in which 00 is electrically connected in series.
Is shown in

As shown in FIGS. 5B and 5C, a silver-plated copper foil (bus bar electrode) 506 with a PET tape extending outward from the photovoltaic element 500 is connected to the adjacent photovoltaic element 5.
00, the soft copper foil 503 on the back side
And solder (Pb 37%, Sn 63%). At this time, the PET tape 507 is connected to the adjacent photovoltaic
The connection was made so as to come into contact with the edge portion. Although the figure shows the case of two series, five photovoltaic elements 500 are actually connected in series.

Next, as shown in FIG. 5C, a bypass diode 508 in which a PN chip diode is only electrically connected between two copper foils by high-temperature solder is provided on the back side of the photovoltaic element 500. And the external connection terminal connected to the P side of the bypass diode 508 is connected to the backside soft copper foil 503.
And an external connection terminal connected to the N side of the bypass diode 508 is soldered to the bus bar electrode 506 (Pb95
%, Sn 5%) to secure electrical continuity. One bypass diode 508 was connected to one photovoltaic element.

Next, these five series photovoltaic element modules 500 were coated with a resin (lamination) in a configuration as shown in FIG. The procedure is described below.

First, as shown in FIG.
3, surface sealing material 604, sealing material 605, back surface sealing material 60
6, a back insulator 607 and a reinforcing plate 608 were prepared. In FIG. 6, reference numeral 601 denotes a photovoltaic element, and 602 denotes a bypass diode. Specific materials are shown below.

<Surface Member> The surface member 603 has a thickness of 50%.
A ETFE film having a thickness of μm was formed, and the surface to be bonded to the surface sealing material 604 was subjected to plasma treatment in advance.

<Surface Sealant> The surface sealant 604 is made of EV.
A (vinyl acetate content: 33 wt%): 100 wt%, t-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent: 1.5 wt%, 2-hydroxy-4-n-octoxybenzophenone as an ultraviolet absorber: 0 wt% .3w
0.2% by weight of tris (mono-nonylphenyl) phosphite as an antioxidant, and 0.1% by weight of (2,2,6,6-tetramethyl-4-piperidyl) sebacate as a light stabilizer. The mixture was mixed and formed into a sheet having a thickness of 230 μm using a T-table and an extruder, and further embossed with a thickness of 15 μm using an emboss roll.

<Sealant> The sealant 605 used was the same as the surface sealant 604 except that the vinyl acetate content was 15 wt%. In addition, five sheets were prepared so as to completely cover the bypass diode 602.

<Back Sealing Material> As the back sealing material 606, the same material as the front sealing material 604 was used.

<Back Insulator> A back insulator 607 is a biaxially stretched PET film (thickness 10
0 μm), and a surface sealing material 604 is provided on the reinforcing plate 608 side.
The same resin having a thickness of 200 μm was laminated.

<Reinforcing Plate> As the reinforcing plate 608, a galvanized steel plate having a thickness of 0.4 mm was prepared.

The above materials were laminated as shown in FIG. 6, and a stainless steel mesh (40 × 40 mesh, wire diameter 0.15 mm) was placed on the outside of the ETFE through a Teflon film (thickness: 50 μm) for release. The solar cell module was obtained by heating and pressing at 150 ° C. for 30 minutes while pressurizing and degassing the laminate using a vacuum laminating apparatus. On the surface of the surface member 603, a maximum of 30 μm
The unevenness of the height difference was formed.

<Solar Cell Module> This solar cell module will be described with reference to FIG.

FIG. 7 is a perspective view of a solar cell module using the photovoltaic element module of the present invention.

As shown in FIG. 7, the solar cell module 7
The output terminal No. 00 was previously turned on the back surface of the photovoltaic element 601 so that after lamination, the output could be taken out from the terminal outlet previously opened in the galvalume steel plate 702.

Further, in the solar cell module 700, a portion of the reinforcing plate 702 extending outside the photovoltaic element 701 is bent by a roller former, and the reinforcing plate 702 is directly used as a roof material. It is a "roof material integrated solar cell module" that performs its function.

In this manner, a roof material-integrated solar cell module A was produced using the photovoltaic element module of Example 1.

<Example 2> In Example 2, a roof material-integrated solar cell module B was produced using a photovoltaic element module.

In the photovoltaic element module according to the second embodiment, the sealing material 605 is made of E having a vinyl acetate content of 18 wt%.
Example 2 was different from Example 1 in that VA was used, and was otherwise identical to the photovoltaic element module of Example 1.

Example 3 In Example 3, a roof material-integrated solar cell module C was produced using a photovoltaic element module.

In the photovoltaic element module according to the third embodiment, the sealing material 605 was made of E having a vinyl acetate content of 20 wt%.
The difference from the photovoltaic element module of Example 1 was that VA was used, and the rest was made exactly the same as the photovoltaic element module of Example 1.

Comparative Example 1 A roof material-integrated solar cell using the photovoltaic element module of Comparative Example 1 was compared with the solar cell module using the photovoltaic element modules of Examples 1 to 3 described above. Module D was created.

In the photovoltaic element module of Comparative Example 1, the sealing material 605 was made of E having a vinyl acetate content of 23 wt%.
The difference from the photovoltaic element module of Example 1 was that VA was used, and the rest was made exactly the same as the photovoltaic element module of Example 1.

<Comparative Example 2> A roof material-integrated solar cell using the photovoltaic element module of Comparative Example 2 was compared with the solar cell module using the photovoltaic element modules according to Examples 1 to 3 described above. Battery module E was created.

In the photovoltaic element module of Comparative Example 2, the sealing material 605 was made of E having a vinyl acetate content of 33 wt%.
The difference from the photovoltaic element module of Example 1 was that VA was used, and the rest was made exactly the same as the photovoltaic element module of Example 1.

Example 4 In Example 4, a roof material-integrated solar cell module F was manufactured using a photovoltaic element module.

As shown in FIG. 8, the photovoltaic element module of Example 4 is provided with a sealing material 805 as a single sheet, and is set larger than the photovoltaic element module. This is different from the photovoltaic element module of Example 1 in that it was not provided.
Was produced in exactly the same manner as the photovoltaic element module of (1).

In FIG. 8, reference numeral 801 denotes a photovoltaic element;
02 is a bypass diode, 803 is a surface member, 804
Is a surface sealing material, 805 is a sealing material, 807 is a back surface insulating material,
Reference numeral 808 indicates a reinforcing plate. In FIG. 8, the upper direction is the light incident side.

Example 5 In Example 5, a roof material-integrated solar cell module G was produced using a photovoltaic element module.

The photovoltaic element module of Example 5 is different from Example 1 in that EEA (ethyl acrylate 20 wt%, thickness 200 μm) was used instead of EVA as a sealing material.
The photovoltaic element module of Example 1 was different from the photovoltaic element module of Example 1 except for that.

Example 6 In Example 6, a roof material-integrated solar cell module H was manufactured using a photovoltaic element module.

The photovoltaic element module of the fifth embodiment is different from the photovoltaic element module of the fifth embodiment in that the encapsulant is provided as a single sheet larger than the module and the back encapsulant is not provided. The photovoltaic device module was different from the photovoltaic device module of Example 5 except for the device module.

<Example 7> In Example 7, a roof material-integrated solar cell module I was manufactured using a photovoltaic element module.

The photovoltaic element module according to the seventh embodiment differs from the photovoltaic element module according to the first embodiment in that no reinforcing plate is provided and no EVA is provided on the reinforcing plate side of the back surface insulator. The photovoltaic element module of Example 1 was manufactured in exactly the same manner as the photovoltaic element module of Example 1 except for the above. In the photovoltaic element module of Example 7, no bending was performed because no reinforcing plate was provided.

Example 8 In Example 8, a roof material-integrated solar cell module J was produced using a photovoltaic element module.

The photovoltaic element module of Example 8 differs from the photovoltaic element module of Example 7 in that a glass plate having a thickness of 2.5 mm is used instead of ETFE as a surface member. Except for this, the module was manufactured in exactly the same manner as the photovoltaic element module of Example 7.

<Comparative Experiment 1> The above-mentioned roof-integrated solar cell modules A to J were installed on the same installation table as the actual roof, and the following outdoor environment conditions were assumed. An experiment was performed.

Note that the module I was installed by simple stationary installation because there was no reinforcing plate. The test (1) is a test assuming the intrusion of moisture outdoors, and the test (2) is a test assuming corrosion when a solar cell is installed in a salt-affected area.

(1) High-temperature and high-humidity test In the high-temperature and high-humidity test, a high-temperature and high-humidity test (temperature: 85 ° C., humidity: 85%) conforming to the IEEE standard draft9 is 8000.
Time went. Then, every 500 hours, the efficiency of the solar cell was measured and the failure of the bypass diode was confirmed. After the test, the module was disassembled and the appearance of the bypass diode was observed.

(2) Salt Spray Test In the salt spray test, 100 cycles of a salt water corrosion test based on JASO M609 were performed. In this test, as in the high-temperature high-humidity test, the efficiency of the solar cell was measured and the failure of the bypass diode was checked every 10 cycles. After the test, the module was disassembled and the appearance of the bypass diode was observed.

Table 1 shows the results of the comparative experiment.

The meanings of the symbols of the visual inspection in Table 1 are as follows.
It is as follows. ：: No particular corrosion is seen on the metal part (solder part) on the appearance. ：: A case where a little corrosion was observed in appearance, but it seemed to have little effect. Δ: Corrosion has progressed to some extent. X: When corrosion is severe.

[0121]

[Table 1]

As is clear from Table 1, the solar cell modules A (Example 1), B (Example 2), C (Example 3), D (Comparative Example 1), and E (Comparative Example 2) Although the amount of vinyl acetate was changed, in both the high-temperature and high-humidity test and the salt spray test, when the amount of vinyl acetate was 20 wt% or less, there was no failure of the bypass diode. did.

Further, in terms of appearance, the amount of vinyl acetate is 20w.
When the amount exceeds t%, the corrosion was severe, and blue rust was generated in the copper portion and white rust was generated in the solder portion. From these comparison results, it is clear that the corrosion resistance is significantly improved when the amount of vinyl acetate is 20% by weight or less. In addition, no failure occurred in any of the configurations of the solar cells.

Next, a solar cell module G (Example 5)
And H (Example 6), EEA instead of EVA
Although no corrosion occurred at all, it can be seen that the use of EEA further excels in corrosion protection.

Further, the case where a galvalume steel plate or a glass plate as a reinforcing plate is provided or not (the solar cell module I
(Example 7), there is a clear difference in failure life and appearance, and it is found that a certain case is more effective.

From the above results, it can be considered that the photovoltaic element module of the present invention has improved corrosion resistance as compared with the conventional one.

[0127]

Since the photovoltaic element module of the present invention has the above-described structure, it can have excellent corrosion resistance. Therefore, especially in a humid region or a region where the temperature difference between day and night is large, the failure life of the solar cell module using the photovoltaic element module can be extended and the reliability can be improved.

Further, in a building material integrally using the photovoltaic element module of the present invention, corrosion resistance can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a photovoltaic element module according to an embodiment of the present invention.

FIG. 2 is a schematic view of an example of a conventional solar cell module.

FIG. 3 is a schematic view of a photovoltaic element module according to another embodiment of the present invention.

FIG. 4 is a perspective view of a building material using the photovoltaic element module of the present invention.

FIG. 5 is a schematic configuration diagram showing an appearance of a photovoltaic element module of the present invention.

FIG. 6 is a schematic diagram of a photovoltaic element module according to Embodiment 1 of the present invention.

FIG. 7 is a perspective view of a solar cell module using the photovoltaic element module of the present invention.

FIG. 8 is a schematic view of a photovoltaic element module according to Embodiment 4 of the present invention.

[Explanation of symbols]

101,201,301,500,601,701,8
01 Photovoltaic element 103, 207, 603, 803 Surface member 105, 305, 605, 805 Sealant 106, 306, 606 Backside sealant 107, 307, 607, 807 Backside insulator 108, 303, 702, 608 , 808 Reinforcement plate 202, 506 Busbar electrode 203, 507 Insulating tape 204 Metal body 205, 505 Current collecting electrode 206 Solder 104, 208, 304, 604, 804 Surface sealant 209 Backside sealant 210 Backside member 400 Building material 401 Fixed Member 501 Etching line 503 Electrode 504 Insulating member 102, 302, 508, 602, 802 Bypass diode

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshifumi Takeyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tsutomu Murakami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Takeshi Yoshino 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc. 2E162 CA24 CB02 CB07 CB21 CD04 5F051 BA18 JA04 JA06 JA07 JA08 JA09

Claims (5)

[Claims] 1. A photovoltaic element module having one or more bypass diodes connected thereto and sealed with one or more kinds of sealing materials, wherein the photovoltaic element module is provided in contact with at least the bypass diode. The encapsulant is made of a resin having a content of a component that generates an acid by hydrolysis or thermal decomposition of 20% or less. 2. The resin according to claim 1, wherein the resin is a copolymer resin of ethylene and an unsaturated fatty acid ester.
Or the photovoltaic element module according to 2. 3. The photovoltaic element module according to claim 2, wherein said unsaturated fatty acid ester is ethyl acrylate or methyl acrylate. 4. The photovoltaic element module according to claim 1, wherein the photovoltaic element module is formed on a reinforcing plate. 5. A building material, wherein the photovoltaic element module according to claim 1 and a building material main body have an integral structure.