WO2018150893A1

WO2018150893A1 - Solar cell module

Info

Publication number: WO2018150893A1
Application number: PCT/JP2018/003424
Authority: WO
Inventors: 直樹栗副; 善光生駒; 剛士植田; 元彦杉山
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-02-17
Filing date: 2018-02-01
Publication date: 2018-08-23
Also published as: JPWO2018150893A1

Abstract

A solar cell module is provided with a photoelectric conversion unit, resin layers (24, 26) covering at least one surface side of the photoelectric conversion unit, and a surface protective substrate (20) and a rear surface protective substrate (28) between which the photoelectric conversion unit and the resin layers (24, 26) are sandwiched. The surface protective substrate (20) comprises a resin. The photoelectric conversion unit comprises a plurality of solar cells (10) and tab wiring (12) for electrically connecting the plurality of solar cells (10) with each other. A black coating (30) in which L*(SCE) as defined by the CIE 1976 color space is 40 or less is formed on the surface of the tab wiring (12).

Description

Solar cell module

The present invention relates to a solar cell module.

The solar cell module has, as a basic configuration, a first substrate made of a resin or the like, a first resin layer, a photoelectric conversion unit, a second resin layer, a second substrate made of a resin or the like, In this order. That is, the photoelectric conversion unit is protected by covering the front and back surfaces of the photoelectric conversion unit with the first substrate and the first resin layer, and the second resin layer and the second substrate. In such a configuration, in the photoelectric conversion unit, a plurality of solar cells are arranged in a matrix, and adjacent solar cells are electrically connected by tab wiring (see, for example, Patent Document 1). In this manner, the photoelectric conversion unit electrically connects the plurality of photovoltaic cells with the plurality of tab wirings, and increases the output voltage, for example.

JP 2012-134210 A

However, since the tab wiring is made of metal, according to the above configuration, when the solar cell module is used for a long time, metal ions derived from the constituent metal of the tab wiring may diffuse into the first and second resin layers. is there. As a result, there is a problem that the transparency of the resin layer is lowered, the amount of light reaching the solar battery cell is reduced, and the power generation efficiency is lowered. Therefore, for example, when the resin layer is made of ethylene vinyl acetate and the tab wiring is made of copper, when copper ions originating from the tab wiring diffuse into the resin layer, the copper ions promote the decomposition of ethylene vinyl acetate. As a result, the resin layer becomes yellowish. As a result, it causes a decrease in transparency and a decrease in power generation efficiency. Such a problem is remarkable when the 1st board | substrate of a solar cell module is formed with resin.

On the other hand, since the tab wiring has a metallic luster, the incident light on the tab wiring is specularly reflected. Therefore, sunlight incident on the solar cell module is reflected by the tab wiring. Therefore, for example, when a solar cell module is installed, a person who passes nearby may feel dazzling due to sunlight reflected on the solar cell module. Further, the tab wiring is a metal color, the solar battery cell is black, and the two are different in color, so that the tab wiring is conspicuous and there is no sense of unity.

The present invention has been made in view of such problems of the conventional technology. And the objective of this invention is providing the solar cell module which can suppress the fall of the power generation efficiency resulting from the fall of the transparency of the resin layer which covers a photoelectric conversion part, and reflection of sunlight.

The solar cell module according to the first aspect of the present invention includes a photoelectric conversion unit, a resin layer covering at least one surface side of the photoelectric conversion unit, a surface protection substrate and a back surface protection substrate sandwiching the photoelectric conversion unit and the resin layer. And comprising. The surface protection substrate is made of a resin, and the photoelectric conversion unit has a plurality of solar cells and tab wiring that electrically connects the plurality of solar cells. And the black-type film whose L ^* (SCE) prescribed | regulated by the CIE1976 color system is 40 or less is formed on the surface of the tab wiring.

The solar cell module according to the second aspect of the present invention includes a photoelectric conversion unit, a resin layer covering at least one surface side of the photoelectric conversion unit, a surface protection substrate and a back surface protection substrate sandwiching the photoelectric conversion unit and the resin layer. And comprising. The surface protection substrate is made of a resin, and the photoelectric conversion unit has a plurality of solar cells and tab wiring that electrically connects the plurality of solar cells. And the black-type film of L ^* (SCE) whose difference with L ^* (SCE) prescribed | regulated by the CIE1976 colorimetric system of the photovoltaic cell surface is 15 or less is formed on the surface of the tab wiring.

The solar cell module according to the third aspect of the present invention includes a photoelectric conversion unit, a resin layer covering at least one surface side of the photoelectric conversion unit, a surface protection substrate and a back surface protection substrate sandwiching the photoelectric conversion unit and the resin layer. And comprising. The photoelectric conversion unit includes a plurality of solar cells and a tab wiring that electrically connects the plurality of solar cells, and the surface of the tab wiring has L ^* (SCE) defined by the CIE1976 color system. ) Is 40 or less.

A solar cell module according to a fourth aspect of the present invention includes a photoelectric conversion unit, a resin layer covering at least one surface side of the photoelectric conversion unit, a surface protection substrate and a back surface protection substrate sandwiching the photoelectric conversion unit and the resin layer. And comprising. The photoelectric conversion unit includes a plurality of solar cells and a tab wiring that electrically connects the plurality of solar cells. And the black-type film of L ^* (SCE) whose difference with L ^* (SCE) prescribed | regulated by the CIE1976 colorimetric system of the said photovoltaic cell surface is 10 or less is formed in the surface of a tab wiring.

FIG. 1 is a top view showing a solar cell module according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the solar cell module shown in FIG. FIG. 3 is a cross-sectional view showing a connection state between the solar battery cell and the tab wiring. FIG. 4 is a cross-sectional view of a tab wiring on which a black film is formed. 5A is a top view, FIG. 5B is a front view, and FIG. 5C is a bottom view of the tab wiring in the state shown in FIG. 2. FIG. 6 is a (a) top view, (b) front view, and (c) bottom view of the tab wiring before being connected to the solar battery cell. FIG. 7 is a diagram schematically showing a manufacturing process of a tab wiring having a substantially rectangular cross section. FIG. 8 is a diagram schematically showing a manufacturing process of a tab wiring having a circular cross section.

Hereinafter, the solar cell module according to the present embodiment will be described with reference to the drawings. FIG. 1 is a top view showing a solar cell module 100 according to the present embodiment. As shown in FIG. 1, a rectangular coordinate system composed of an x-axis, a y-axis, and a z-axis is defined. The x axis and the y axis are orthogonal to each other in the plane of the solar cell module 100. The z axis is perpendicular to the x axis and the y axis and extends in the thickness direction of the solar cell module 100. Further, the positive directions of the x-axis, y-axis, and z-axis are each defined in the direction of the arrow in FIG. 1, and the negative direction is defined in the direction opposite to the arrow. Of the two main surfaces forming the solar cell module 100 and parallel to the xy plane, the main plane arranged on the positive side of the z-axis is the “light receiving surface (surface)”. The main plane disposed on the negative direction side of the z-axis is the “back surface”. The “light receiving surface (front surface)” means a surface on which light is mainly incident, and the “back surface” may mean a surface opposite to the light receiving surface. Further, the positive direction side of the z-axis may be referred to as “light-receiving surface side”, and the negative direction side of the z-axis may be referred to as “back surface side”.

In addition, in the description such as “providing the second member on the first member”, the first member and the second member may be provided in direct contact unless otherwise specified. There may also be other members between the second member. “Upper” in the above description may be on the positive side of the z axis or on the negative side of the z axis. Furthermore, “substantially” indicates that they are different within the error range, that is, substantially the same.

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

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

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

Further, a plurality of connection wires 14 extend in the x-axis direction on the positive and negative sides of the y-axis of the solar cell string 16, and the connection wires 14 electrically connect two adjacent solar cell strings 16. Connecting.

In the above configuration, the solar cell module of the present embodiment includes a photoelectric conversion unit, a resin layer covering at least one surface side of the photoelectric conversion unit, a surface protection substrate and a back surface protection substrate that sandwich the photoelectric conversion unit and the resin layer. And comprising. And a photoelectric conversion part has a some photovoltaic cell and tab wiring which connects a plurality of photovoltaic cells electrically. Further, on the surface of the tab wiring, L ^* (SCE) defined by the CIE 1976 color system is 40 or less, and a ^* and b ^* are preferably a ^* of −10 to 20, and b ^* of −20 to Ten black coatings are formed.
Here, L ^* (SCE) means the lightness L ^* measured by the SCE method, which is a method for measuring the color by removing regular reflection light. In the following description, the values are based on the SCE method unless otherwise indicated.

Further, the solar cell module of the present embodiment includes a photoelectric conversion unit, a resin layer covering at least one surface side of the photoelectric conversion unit, a surface protection substrate and a back surface protection substrate sandwiching the photoelectric conversion unit and the resin layer. Prepare. And a photoelectric conversion part has a some photovoltaic cell and tab wiring which connects a plurality of photovoltaic cells electrically. Further, on the surface of the tab wiring, a black film of L ^* (SCE) having a difference of 10 or less from L ^* (SCE) defined by the CIE1976 color system on the surface of the solar battery cell is formed.

Each of the combination of the solar battery cell 10 and the tab wiring 12 and the solar battery string 16 may be a “photoelectric conversion unit”, and the combination of the plurality of solar battery strings 16 and the connection wiring 14 is a “photoelectric conversion unit”. May be. Note that a frame (not shown) may be attached to the edge portion of the solar cell module 100. The frame protects the edge of the solar cell module 100 and is used when the solar cell module 100 is installed on a roof or the like.

FIG. 2 is a cross-sectional view showing the solar cell module 100. The solar cell module 100 includes a solar cell 10, a tab wire 12, a connection wire 14, a solar cell string 16, a surface protection substrate 20, a resin layer 24, a resin layer 26, and a back surface protection substrate 28. The upper side in FIG. 2 corresponds to the back surface side, and the lower side corresponds to the light receiving surface side.

The surface protection substrate 20 protects the surface of the solar cell module 100 and is made of resin. For example, a polycarbonate resin having translucency is used. Moreover, although the surface protection board | substrate 20 is formed in the rectangular plate shape of thickness 1mm, it is not limited to this.

Examples of the transparent resin constituting the surface protection substrate 20 include polyethylene (PE), polypropylene (PP), cyclic polyolefin, polycarbonate (PC), polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE), and polystyrene (PS). ), At least one selected from the group consisting of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). Among these, it is preferable to use polycarbonate (PC) as the substrate 20. This is because polycarbonate (PC) is excellent in impact resistance and translucency and is suitable for protecting the surface of the solar cell module 100. Further, the surface protection substrate 20 may include a hard coat layer made of acrylic urethane or the like on the surface. Furthermore, the surface protective substrate 20 or the hard coat layer may contain an ultraviolet absorber, a gloss adjusting agent, and an antireflection component.

The resin layer 24 is disposed on the negative side of the z-axis of the surface protection substrate 20. As the resin layer 24, for example, a thermoplastic resin such as a resin film such as EVA, PVB (polyvinyl butyral), or polyimide is used. A thermosetting resin may be used. Here, especially EVA is used. The resin layer 24 is formed of a rectangular sheet material having translucency and having a surface having substantially the same dimensions as the xy plane of the surface protection substrate 20.

As described above, the solar cell string 16 is formed by connecting a plurality of solar cells 10 arranged in the y-axis direction by the tab wiring 12. The connection wiring 14 is connected to the positive side end and the negative side end of the y axis of the solar cell string 16. Such connection wiring 14 and solar cell string 16 are arranged on the negative side of the z-axis of the resin layer 24. Each of the plurality of solar cells 10 is formed in a flat plate shape having a light receiving surface and a back surface.

The resin layer 26 is disposed on the negative direction side of the z-axis of the connection wiring 14, the solar cell string 16, and the resin layer 24. Therefore, the connection wiring 14 and the solar cell string 16 are sealed by the resin layer 24 and the resin layer 26. Specifically, the light receiving surface of the solar battery cell 10 is disposed so as to contact the resin layer 24, and the back surface of the solar battery cell 10 is disposed so as to contact the resin layer 26.
The resin layer 26 may be formed of the same material as the resin layer 24, or may be formed of a material different from that of the resin layer 24.

The back surface protection substrate 28 is disposed on the negative direction side of the z axis of the resin layer 26. The back surface protection substrate 28 protects the back surface side of the solar cell module 100 as a back sheet.

As the material constituting the back protective substrate 28, glass, fiber reinforced plastic (FRP), polyimide (PI), cyclic polyolefin, polycarbonate (PC), polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), polystyrene ( At least one selected from the group consisting of PS), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN) can be used. Examples of the fiber reinforced plastic (FRP) include glass fiber reinforced plastic (GFRP), carbon fiber reinforced plastic (CFRP), and aramid fiber reinforced plastic (AFRP). In addition, glass epoxy etc. are mentioned as a glass fiber reinforced plastic (GFRP). The material forming the back protective substrate 28 preferably contains at least one selected from the group consisting of fiber reinforced plastic (FRP), polymethyl methacrylate (PMMA), and polyether ether ketone (PEEK). The back surface protection substrate 28 is preferably made of a fiber reinforced resin such as a fiber reinforced plastic in order to sufficiently secure the strength. Further, the fiber-reinforced plastic may be a UD (UniDirection) material in which fibers are arranged in one direction, or may be a woven material woven by fibers that intersect each other. When the UD material is used for the back surface protection substrate 28, it is difficult to expand and contract in the fiber direction. Therefore, depending on the direction in which the UD material is arranged, damage to the solar battery cell 10 and cutting of the tab wiring 12 can be suppressed. In addition, since it is hard to produce bending and it is lightweight, it is preferable that the back surface protection board | substrate 28 is formed with the carbon fiber reinforced plastics. Further, in order to increase the efficiency of power generation on the back surface, the main layer may contain titanium oxide or the like to improve the reflectance. Also, the surface may be plated.

Although the thickness of the back surface protection substrate 28 is not particularly limited, it is preferably 0.01 mm or more and 10 mm or less, more preferably 0.05 mm or more and 5.0 mm or less, and 0.07 mm or more and 1.0 mm or less. More preferably. In particular, in the case of fiber reinforced plastic, it is preferable that the diameter of one fiber is the lower limit of thickness. By setting the thickness of the back surface protection substrate 28 in such a range, the deflection of the back surface protection substrate 28 can be suppressed, and the solar cell module 100 can be further reduced in weight.

In the above configuration, a predetermined black film is formed on the surface of the tab wiring of the solar cell module of the present embodiment. Hereinafter, the tab wiring will be described in detail.

The tab wiring is formed of metal wiring (for example, copper, silver, gold). As described above, the metal ions from this metal wiring are provided for buffering, especially on the light incident side, after long-term use. If it diffuses into the resin layer and its transparency is lowered, the power generation efficiency may be reduced. Further, since the tab wiring has a metallic luster, there is a problem that sunlight is specularly reflected as it is, and the reflected light makes a person feel dazzling. Therefore, in the present embodiment, a black film is formed on the surface of the tab wiring to suppress the diffusion of metal ions and the reflection of sunlight as described above.

In the present embodiment, there are two modes for the black film formed on the surface of the tab wiring. In the first aspect, L ^* (SCE) defined by the CIE 1976 color system is 40 or less, and a ^* and b ^* are preferably a ^* of −10 to 20, and b ^* of −20 to 10. It is a black film. The second aspect is the black color film of ^L * is defined by CIE1976 colorimetric system of the solar cell surface (SCE) difference is 10 or less in the ^L * (SCE) with. In any aspect, the following effects are produced. (1) The diffusion of metal ions derived from the metal of the tab wiring into the resin layer is blocked by the black film formed on the surface of the tab wiring. As a result, coloring of the resin layer due to diffusion of metal ions is suppressed, and a decrease in transparency of the resin layer can be suppressed. As a result, a decrease in power generation efficiency can be suppressed. (2) The black coating formed on the surface of the tab wiring eliminates the specular reflection on the surface of the tab wiring and suppresses the reflection of sunlight. Therefore, the resident near the house where the solar cell module of this embodiment is arranged does not feel dazzling due to the reflection of sunlight. (3) Since both the solar battery cell and the tab wiring are black, the tab wiring does not stand out and a sense of unity in appearance can be obtained.

The black film of the first embodiment has an L ^* (SCE) defined by the CIE 1976 color system of 40 or less, a ^* and b ^* are preferably a ^* of −10 to 20, and b ^* of −20 to 10 black coatings. In other words, “black” includes not only black but also dark blue or green. In particular, if L ^* exceeds 40, the reflection of sunlight cannot be suppressed. The black coating of the first aspect preferably has an L ^* (SCE) of 30 or less from the viewpoint of preventing reflection of sunlight and making the tab wiring inconspicuous, and a ^* is 0 to 15 and b ^* is −10. More preferably, it is ˜5.

The black coating of the second aspect is a black coating of L ^* (SCE) having a difference of 15 or less from L ^* (SCE) defined by the CIE 1976 color system on the solar cell surface. Although the color of the surface of the solar battery cell is black, the reflection of sunlight can be suppressed and the tab wiring becomes inconspicuous if the surface of the black film is black as much as the surface of the solar battery cell. The solar cell L ^* (SCE) is usually about 0-30. Therefore, the difference in L ^* (SCE) defined by the CIE1976 color system on the surface of both the solar battery cell and the black coating is defined as 15 or less. When the difference exceeds 10, reflection of sunlight is not suppressed, and tab wiring becomes conspicuous. The difference of L ^* (SCE) is preferably 10 or less.

The following content is common to both the black and white coatings of the first and second aspects.

The black film is not particularly limited as long as it is a material from which a black film having the above L ^* a ^* b ^* value or L ^* value can be obtained. Examples thereof include a coating made of a black material such as black chrome, black chrome, black nickel, or black alumite, and a resin coating using a black pigment. Especially, it is preferable to consist of at least 1 selected from the group which consists of black-type chromium, black-type chromate, black-type nickel, and black-type alumite. By selecting these materials, a black film having the above L ^* a ^* b ^* value or L ^* value can be obtained.

Moreover, it is preferable that the surface of the tab wiring has a region where no black film is formed on at least the surface on the solar cell side. As shown in FIG. 3, the surface of the tab wiring 12 on the solar battery cell 10 side is connected to the solar battery cell 10 via the silver electrode 34. Therefore, it is preferable not to form a black film in the adhesion region between the tab wiring 12 and the silver electrode 34 in order to ensure sufficient adhesion.

Further, as shown in FIG. 4, the tab wiring 12 is formed with the black coating 30 from the upper surface to the side surface, and is not formed with the black coating 30 in the vicinity of the adhesion region with the silver electrode 34. An uncoated region 36 is provided. As described above, the area of the region where the black coating 30 is formed on the surface of the tab wiring 12 is configured to be larger than the area of the region where the black coating 30 is not formed (the coating non-forming region 36). It is preferable to do. By adopting such a configuration, the area directly contacting the resin layer on the side surface of the tab wiring 12 is reduced, and diffusion of metal ions into the resin layer can be sufficiently suppressed. In FIG. 3, the tab wiring 12 and the silver electrode 34 are bonded by the conductive connection body 32. As the conductive connection body 32, for example, a conductive adhesive paste, a conductive adhesive film, an anisotropic conductive adhesive, solder plating, or the like can be used.

FIG. 5 is a (A) top view, (B) front view, and (C) bottom view of one tab wiring 12 in FIG. As shown in FIG. 5, it can be seen that the black film 30 and the film non-formation region 36 are alternately formed on the front and back of the tab wiring 12. That is, in order to directly connect the plurality of solar cells 10, the tab wiring 12 is alternately connected to the upper surface of the solar cell 10 and then to the lower surface of the adjacent solar cell 10. Therefore, the black coating 30 and the coating non-formation region 36 are alternately formed on the upper and lower surfaces of the tab wiring 12.

The film thickness of the black coating is preferably from 0.01 to 100 μm, more preferably from 0.1 to 10 μm, from the viewpoint of preventing diffusion of metal ions in the tab wiring into the resin layer.

On the other hand, when many tab wirings 12 are manufactured, it is efficient to carry out as follows. That is, as shown in FIG. 6, wires having a length corresponding to the number of tab wires to be manufactured are prepared, and the black coating 30 and the coating non-formation regions 36 are alternately arranged on the front and back surfaces thereof. Then, a black coating 30 is formed, and finally cut at a predetermined portion to obtain a tab wiring. Specifically, as shown in FIG. 7, first, a long wiring that is the basis of the tab wiring 12 is prepared (FIG. 7A). Next, a mask 40 is provided in a portion intended to be a non-coating region 36 (FIG. 7B), and in this state, a black coating 30 is formed by plating (FIG. 7C). Finally, the mask 40 is removed (FIG. 7D), and the tab wiring 12 having the black coating 30 and the non-coating region 36 shown in FIG. Complete.

Also, as described above, when a black film is formed using a mask, the end of the black film protrudes when the mask is removed (see FIG. 4). In this state, when the tab wiring is bonded to the silver electrode on the solar battery cell, the conductive connector used for bonding is easily joined to the end of the black film, and the diffusion of Cu ions to the resin layer is suppressed. be able to. In order to obtain such a configuration, it is preferable that the cross-sectional shape of the tab wiring is a circular shape or a rectangular shape with a corner removed or a rounded shape. FIG. 8 shows a manufacturing process of a tab wiring having a circular cross section. (A) to (D) in FIG. 8 are the same as the steps (A) to (D) in FIG.

As described above, in the solar cell module of the present embodiment, the black coating 30 is formed on the surface of the tab wiring 12. Therefore, it is possible to suppress the metal ions from the tab wiring 12 from diffusing into the resin layers 24 and 26 provided for buffering the solar battery cell 10, particularly the resin layer 24 on the light incident side. As a result, a decrease in transparency of the resin layers 24 and 26 is suppressed, and a decrease in power generation efficiency can be suppressed.

The solar battery cell 10 appears to be black because it absorbs visible light (converts it into electricity), but when the black coating 30 is formed on the surface of the tab wiring 12, the solar battery 10 and the tab wiring 12 have the same color. It becomes. Therefore, the tab wiring 12 is not conspicuous, and the sense of unity in appearance as the solar cell module 100 is also increased.

Further, when the black coating 30 is not formed on the surface of the tab wiring 12, as described above, the surface of the tab wiring 12 acts as a reflecting surface and reflects sunlight. On the other hand, when the black coating 30 is formed on the surface of the tab wiring 12, the temperature is slightly increased and expanded because the light is absorbed. The behavior is similar to the behavior in which the solar cell 10 expands as the temperature rises, and thus leads to the reduction of stress at the connection point between the solar cell 10 and the tab wiring 12. Also in that respect, the solar cell module 100 is stabilized in the long term.

Next, a method for manufacturing the solar cell module 100 will be described.
The solar cell module 100 is manufactured by laminating the solar cell string 16 with the surface protection substrate 20, the resin layer 24, the resin layer 26, and the back surface protection substrate 28. In the laminating apparatus, for example, the surface protection substrate 20, the resin sheet constituting the resin layer 24, the strings of the solar battery cells 10, the resin sheet constituting the resin layer 26, and the back surface protection substrate 28 are sequentially laminated on the heater. This laminated body is heated to about 150 ° C. in a vacuum state, for example. Thereafter, heating is continued while pressing each component member on the heater side under atmospheric pressure to crosslink the resin component of the resin sheet.

Hereinafter, the present embodiment will be described in more detail by way of examples, but the present embodiment is not limited to these.

[Example 1]
(Production of tab wiring)
As shown in FIG. 5, a black coating was formed by applying black nickel plating to a predetermined position on the front and back sides of a foil-like wiring made of copper. When measured using a spectrocolorimeter CM-600d manufactured by Konica Minolta, L ^* (SCE) defined by the CIE 1976 color system of this black film is 7.9, a ^* is 1.0, b ^* Was -1.1.

(Production of photoelectric conversion part)
Adjacent solar cells were connected to each other by using the tab wiring obtained as described above for a plurality of solar cells arranged in a matrix. In addition, L ^* of the photovoltaic cell was 19 when measured similarly to the black film of the tab wiring. In other words, the difference between L ^* of the black coating of the tab wiring and L ^* of the solar battery cell was 11.1.

(Assembly of solar cell module)
A resin layer (layer thickness: 500 μm) made of an ethylene-vinyl acetate copolymer by a vacuum laminator on both sides of the photoelectric conversion part obtained as described above, and a surface protection substrate and a back protection substrate made of resin on both sides The laminate obtained by arranging was heated to 150 ° C. in a vacuum state. Thereafter, heating was continued while pressing each component member on the heater side under atmospheric pressure to crosslink the resin component of the resin layer. The solar cell module of Example 1 was obtained as described above.

[Comparative Example 1]
A solar cell module was produced in the same manner as in Example 1 except that the black film was not formed on the tab wiring.

<Evaluation>
1. Discoloration The solar cell module produced in each Example / Comparative Example was subjected to a heat resistance test of JISC8917, and the discoloration of the resin on the tab was visually evaluated. 1. Evaluation was made with x indicating discoloration and ◯ indicating no discoloration. Reflection of sunlight Sunlight was incident on the solar cell module from various angles, and whether or not sunlight was reflected was visually observed. Then, the case where there was almost no reflection of sunlight was evaluated as ◯, and the case where glare was felt due to the reflection of sunlight was evaluated as ×.
3. Appearance It was evaluated whether or not the tab wiring was visible from the surface of the solar cell module. The case where the tab wiring was hardly visible was evaluated as ○, and the case where the tab wiring was easily visible was evaluated as ×.

From Table 1, in Examples 1 to 5, excellent results were obtained in any evaluation. In contrast, Comparative Example 1 was inferior to the Examples in all evaluations. From the comparison of the above examples and comparative examples, by forming a black coating on the tab wiring, diffusion of metal ions to the resin layer and reflection of sunlight are suppressed, and the tab wiring cannot be visually recognized. It can be seen that the above sense of unity was obtained.

The surface protection substrate 20 may be made of glass.

The entire contents of Japanese Patent Application No. 2017-027903 (application date: February 17, 2017) and Japanese Patent Application No. 2017-210598 (application date: October 31, 2017) are incorporated herein by reference.

According to the present invention, it is possible to provide a solar cell module capable of suppressing a decrease in power generation efficiency due to a decrease in transparency of a resin layer covering a photoelectric conversion unit and a reflection of sunlight.

10 Solar cell (photoelectric conversion part)
12 Tab wiring 14 Connection wiring 16 Solar cell string (photoelectric conversion part)
DESCRIPTION OF SYMBOLS 20 Surface protective substrate 24 Resin layer 26 Resin layer 28 Back surface protective substrate 30 Black-type coating film 32 Conductive connection body 34 Silver electrode 36 Film non-formation area 40 Mask 100 Solar cell module

Claims

A photoelectric conversion unit;
A resin layer covering at least one surface side of the photoelectric conversion unit;
A surface protection substrate and a back surface protection substrate that sandwich the photoelectric conversion part and the resin layer,
The surface protection substrate is made of resin,
The photoelectric conversion unit includes a plurality of solar cells and a tab wiring that electrically connects the plurality of solar cells,
A solar cell module in which a black film having an L * (SCE) defined by the CIE1976 color system of 40 or less is formed on the surface of the tab wiring.
A photoelectric conversion unit;
A resin layer covering at least one surface side of the photoelectric conversion unit;
A surface protection substrate and a back surface protection substrate that sandwich the photoelectric conversion part and the resin layer,
The surface protection substrate is made of resin,
The photoelectric conversion unit includes a plurality of solar cells and a tab wiring that electrically connects the plurality of solar cells,
On the surface of the tub wiring, solar cell module blackish film is formed of defined by CIE1976 colorimetric system of the solar cell surface L * (SCE) difference is 15 or less in the L * a (SCE) .
3. The solar cell module according to claim 1, wherein the surface of the tab wiring has a region where the black film is not formed on at least the surface on the solar cell side.
4. The solar cell module according to claim 3, wherein an area of the region where the black coating is formed on the surface of the tab wiring is larger than an area of the region where the black coating is not formed.
The black film according to any one of claims 1 to 4, wherein the black film is a film formed of at least one selected from the group consisting of black chromium, black chromate, black nickel, and black alumite. The solar cell module described.
A photoelectric conversion unit;
A resin layer covering at least one surface side of the photoelectric conversion unit;
A surface protection substrate and a back surface protection substrate that sandwich the photoelectric conversion part and the resin layer,
The photoelectric conversion unit includes a plurality of solar cells and a tab wiring that electrically connects the plurality of solar cells,
A solar cell module in which a black film having an L * (SCE) defined by the CIE1976 color system of 40 or less is formed on the surface of the tab wiring.
A photoelectric conversion unit;
A resin layer covering at least one surface side of the photoelectric conversion unit;
A surface protection substrate and a back surface protection substrate that sandwich the photoelectric conversion part and the resin layer,
The photoelectric conversion unit includes a plurality of solar cells and a tab wiring that electrically connects the plurality of solar cells,
On the surface of the tub wiring, solar cell module blackish film is formed of defined by CIE1976 colorimetric system of the solar cell surface L * (SCE) difference is 15 or less in the L * a (SCE) .