JP6528114B2 - Solar cell module - Google Patents

Description

  The present invention relates to a solar cell module.

  Solar cells are expected as a new energy source because they can convert clean and inexhaustible supplied solar energy directly into electrical energy.

  In general, the output per solar cell is about several watts and is fragile. Therefore, when using a solar cell as a power source for a house, a building, etc., the output is increased by electrically connecting a plurality of solar cells, and the solar cell is impacted using glass, a resin filler, etc. A solar cell module configured to protect is used.

  The plurality of solar cells are electrically connected using a conductive wiring material. In general, a wiring material in which a copper core wire is covered with a coating material having conductivity such as solder or silver is used.

  However, since the solar cell module is installed and used outdoors for a long time, copper ions elute from such a wiring material including a core wire made of copper over time. As a result, there is a problem that the eluted copper ions degrade the sealing material disposed around, and the sealing ability of the sealing material is impaired. Therefore, in order to prevent deterioration of the sealing material due to copper ions, it is disclosed to arrange a sheet for preventing diffusion of copper ions between the sealing material and the wiring material containing copper.

JP-A-8-139350

  Here, in the above-mentioned patent documents, the copper diffusion prevention sheet is arranged on the upper surface portion of the wiring material. Usually, the wiring material has a rectangular shape with a flat cross section, and the surface area of the wiring material is large at the top surface and small at the side surface. In order to further extend the life of the solar cell module, diffusion prevention is also required for copper ions eluted from the side surface of the wiring material.

  This invention is made in view of the above, and it aims at providing a solar cell module which reliability improved.

  A solar cell module according to a feature of the present invention is adjacent to a plurality of solar battery cells arranged along the arrangement direction, a plurality of copper wiring members electrically connecting the plurality of solar battery cells, and the copper wiring member A sealing material for sealing a solar battery cell string comprising a copper diffusion preventing sheet, a solar battery cell, a copper wiring material, and a copper diffusion preventing sheet, and a protective member for protecting the surface of the sealing material, Equipped with

  According to the present invention, a solar cell module with improved reliability can be provided.

It is a partial top view of the solar cell module in a 1st embodiment. It is sectional drawing of the AA straight line in FIG. It is sectional drawing of the surface side into which sunlight injects among sectional drawing of the BB straight line in FIG. It is sectional drawing which shows the position of the copper diffusion prevention sheet in the case of arrange | positioning a copper diffusion prevention sheet in the area | region C in FIG. It is a partial top view of the solar cell module in 2nd Embodiment. It is sectional drawing of the CC straight line in FIG. It is sectional drawing of the surface side into which sunlight injects among sectional drawing of the DD straight line in FIG. It is sectional drawing of the DD straight line in FIG. 2, Comprising: It is sectional drawing at the time of applying 3rd Embodiment to a copper diffusion prevention sheet. It is the bird's-eye view from the surface which has the light diffusivity of the copper diffusion prevention sheet in 3rd Embodiment.

  Embodiments according to the present invention will be described using the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios among the drawings are included.

First Embodiment
(Configuration of solar cell module)

  The schematic configuration of the solar cell module 100 according to the first embodiment will be described with reference to FIGS. 1 to 4.

  FIG. 1 is a partial top view of the solar cell module 100 according to the first embodiment. Moreover, FIG. 2 is sectional drawing of the line shown to AA described in FIG.

  According to FIG. 1 and FIG. 2, the solar cell module 100 is provided with a frame 30 made of metal such as aluminum around it. The solar cell module 100 includes a plurality of solar cell strings 9 a formed by connecting a plurality of solar cells 8 using a copper wiring material 3 a electrically connecting adjacent solar cells 8. Furthermore, between the solar cell strings 9a, the copper wiring material 3b which electrically connects between solar cell strings is provided. Furthermore, the solar cell module 100 includes a current extraction tab (not shown) and a terminal box (not shown) electrically connected to the copper wiring member 3b for power extraction.

According to FIG. 2, the solar cell module 100 includes the solar cell string 9a, the sealing materials 6a and 6b for sealing the solar cell strings 9a, and the surface side protective member 10 for further protecting the sealing materials 6a and 6b. The back side protection member 20 is provided. In addition, the arrow shown by S in FIG. 2 shows the surface where sunlight mainly injects, when installing a solar cell module outdoors.

The material of the sealing materials 6a and 6b for sealing the solar cell string 9a from above and below is made of thermoplastic resins including polyolefins, polyethylenes, polyphenylenes and copolymers thereof, or thermosetting resins. It is preferred to select from the group. The sealing materials 6a and 6b are cured by heat and pressure, but at this time, the materials of 6a and 6b may be the same or different, and the combination thereof is not particularly limited. As an example, ethylene vinyl acetate copolymer (EVA) may be used for both 6a and 6b.

As the surface side protection member 10 for further protecting the sealing materials 6 a and 6 b after curing, it is desirable to use a material having high transparency and a hard property such as a glass plate or an acrylic resin plate. In the present embodiment, a tempered glass plate is used. In addition, as the back side protection member 20, a hard material having high weather resistance such as glass, a resin sheet having high flexibility, heat resistance and water resistance, or a composite resin having high weather resistance formed by laminating a plurality of materials. It is preferred to use a sheet. It is further preferable that the color is such that light incident from the light incident surface side can be reflected toward the solar battery cell, and in particular, particles such as titanium oxide (TiO2) and zinc oxide (ZnO) which are light scattering substances Containing polyethylene terephthalate (PE) in a white polyethylene (PE) sheet or EVA sheet
It is most preferable to use a composite resin sheet having a structure in which T) sheets are laminated.

(Detailed Description of Structure of Solar Cell String 9a)
Next, the structure of the solar cell string 9a in the first embodiment will be described in detail with reference to FIG.

  The solar cell string 9a includes a plurality of solar cells 8, a copper wiring member 3a electrically connecting the plurality of solar cells 8, and a copper diffusion prevention sheet 1 disposed on the upper surface side of the copper wiring member 3a. Equipped with

The material of the copper diffusion prevention sheet 1 may be selected from the group consisting of PE, PET, nylon, polycarbonate, polypropylene, polyvinyl chloride, acrylic and the like.

  Although the copper wiring material 3a and the collector electrode 5 are electrically connected, the connection method is not particularly limited. For example, the collector electrode 5 and the copper wiring member 3a may be connected using solder.

  The copper diffusion prevention sheet 1 may be temporarily fixed to the copper wiring material 3a in the end portion (area C in FIG. 1) of the solar cell string 9a using an arbitrary adhesive or tape or the like. In addition, in the process of assembling the solar cell module, any tape or the like may be temporarily fixed to the resin sheet or the like of the sealing material 6a or 6b disposed in advance under the solar cell string 9a. .

  The arrangement method of the copper diffusion prevention sheet 1 at this time is as showing in FIG.1 and FIG.2. The upper surface side of the copper wiring material 3a from end to end of the solar cell string 9a is covered with a single long copper diffusion prevention sheet 1. At this time, the width in the short direction of the copper diffusion prevention sheet 1 is designed to be larger than the width in the short direction of the copper wiring member 3a.

  A desired number of solar battery cell strings 9a thus formed are prepared, and are processed into a solar battery module 100 using a general method.

  Of the B-B cross-sectional view of the solar cell module 100, an enlargement of the upper surface side portion of the solar battery cell 8 is shown in FIG. By pressure heating at the time of formation of the solar cell module, the copper diffusion prevention sheet 1 is bent and deformed and fixed so as to cover the side surface of the copper wiring member 3a. In the present embodiment, the sealing material 6a flows into the space between the copper diffusion prevention sheet 1 and the copper wiring material 3a and is filled with the sealing material 6a, but the copper diffusion prevention sheet 1 is directly copper wiring The material 3a may be coated, or air bubbles may be present between the copper diffusion prevention sheet 1 and the copper wiring material 3a.

Further, in the present embodiment, although the copper diffusion preventing sheet 1 covers both side surfaces of the copper wiring member 3a, even when only one of the upper surface and the side surface is coated, it is effective in preventing the diffusion of copper ions. Furthermore, in the present embodiment, the copper diffusion prevention sheet 1 covers the side surface of the copper wiring member 3a to about half of the thickness direction, but the copper diffusion prevention sheet 1 further widens the copper diffusion prevention sheet 1 to prevent copper diffusion. The sheet 1 may cover the entire thickness direction of the side surface of the copper wiring material 3a, and the width of the copper diffusion prevention sheet 1 is narrowed, and the copper diffusion prevention sheet 1 is only above the side surface of the copper wiring material 3a. May be coated.

  The position where the copper diffusion prevention sheet is disposed is not limited between the copper wiring material 3a and the sealing materials 6a and 6b. For example, copper ions are also eluted from the copper wiring material 3b (region C in FIG. 1). Therefore, as shown in FIG. 4, the copper diffusion prevention sheet 1 may be disposed between the copper wiring 3b and the sealing material 6a, and between the copper wiring 3b and the sealing material 6b. Although the copper wiring material 3a at the relevant portion is in contact with the sealing material 6a on the upper surface side and the sealing material 6b on the lower surface side, the diffusion preventing effect of copper ions can be expected even by covering at least one surface.

Second Embodiment
The schematic configuration of the solar cell module 110 according to the second embodiment will be described with reference to FIGS. 5 to 7. In addition, since the structure of the solar cell module in 2nd Embodiment is the same as 1st Embodiment except one part, a different part from 1st Embodiment is demonstrated in detail here.

(Structure of solar cell module)
FIG. 5 is a partial top view of the solar cell module 110 according to the second embodiment. In this figure, the copper diffusion prevention sheet 1 which covers the copper wiring material 3 a is divided into the same length as one solar battery cell 8 and arranged. Therefore, as shown in FIG. 5, there is an area between the two solar cells 8 where the copper wiring member 3 a can be visually confirmed when the solar cell module 110 is viewed from the top side.

(Detailed Description of Structure of Solar Cell String 9b)
FIG. 6 is a cross-sectional view taken along line C-C in FIG. The example which divided the copper diffusion prevention sheet 1 into the length for every 1 sheet of the photovoltaic cell 8, and has arrange | positioned is shown. The arrangement of the sealing materials 6a and 6b, the front surface side protective member 10, and the rear surface side protective member 20 is the same as that of the first embodiment.

  FIG. 7 is a cross-sectional view showing only the upper surface side of the solar battery cell 8 among the cross-sectional views taken along line D-D in FIG. The copper diffusion prevention sheet 1 is disposed on the copper wiring member 3 a via the first adhesive 2. Further, the copper wiring member 3 a is fixed on the collector electrode 5 formed on the solar battery cell 8 via the second adhesive 4.

The first adhesive 2 for fixing the copper diffusion prevention sheet 1 to the copper wiring member 3a may be made of a material usually used for sealing a solar cell module, such as EVA or PE, for example, acrylic resin, urethane resin Or the like may be used. In the present embodiment, EVA is used. In the present embodiment, although the first adhesive 2 is used in which the first adhesive 2 is applied in advance on one side of the copper diffusion preventing sheet 1, the first adhesive 2 is copper diffused. You may apply | coat, when arrange | positioning the prevention sheet 1 on copper wiring material 3a. In any case, the width of the first adhesive 2 in the short direction is designed to be equal to or shorter than the width of the copper diffusion prevention sheet 1 in the short direction.

  The second adhesive 4 for fixing the copper wiring material 3 a on the collector electrode 5 may or may not contain conductive particles. In the present embodiment, a sheet of resin containing conductive particles is used. When the conductive particles are contained, the copper wiring member 3a and the collector electrode 5 are electrically connected indirectly via the conductive particles. When the conductive particles are not contained, the copper wiring member 3a and the collector electrode 5 are directly electrically connected.

  At the time of forming the solar cell string 9b, when bonding the copper wiring material 3a onto the collecting electrode 5, first, the second adhesive 4 is arranged on the collecting electrode 5, and the copper wiring material 3a is further arranged. Perform thermocompression bonding. Then, the second adhesive 4 is softened, the copper wiring material 3 a is pushed into the second adhesive 4, and a part of the side surface of the copper wiring material 3 a is covered with the second adhesive 4. At this time, the resin sheet of the second adhesive 4 is preferably thicker than the collector electrode 5 and is preferably wider than the copper wiring member 3a. When the second adhesive 4 is not formed in a sheet shape, for example, the second adhesive 4 may be applied so as to be thicker than the collector electrode 5 and wider than the copper wiring member 3a. By doing this, as described above, the second adhesive 4 reliably covers a part of the side surface of the copper wiring 3a.

  Simultaneously with or electrically connecting the collector electrode 5 and the copper wiring member 3a, the copper diffusion prevention sheet 1 is disposed on the copper wiring member 3a. At this time, the first adhesive 2 is applied in advance to the surface of the copper diffusion prevention sheet 1 disposed on the copper wiring material 3a, which is the side facing the copper wiring material 3a. Therefore, the copper diffusion prevention sheet 1 can be fixed on the copper wiring material 3a by performing thermocompression bonding simultaneously with or after arranging on the copper wiring material 3a.

  In the manufacturing process of the solar cell module, the copper diffusion prevention sheet 1 and the first adhesive 2 are bent by heating and curing the sealing materials 6a and 6b, and the copper diffusion prevention sheet 1 or the first adhesive At least one of 2 is deformed and fixed so as to cover the side surface of the copper wiring member 3a.

  The copper wiring material 3b in the portion corresponding to the area C in FIG. 5 may also be covered with the copper diffusion prevention sheet 1 as in the first embodiment.

  In the present embodiment, an example is shown in which resin is used for both i) between the copper diffusion preventing sheet 1 and the copper wiring member 3a, and ii) between the collector electrode 5 and the copper wiring member 3a. There is. However, the resin adhesion method may be applied to either i) or ii), and the other may be the same as in the first embodiment.

Third Embodiment
In the third embodiment, the configuration of the solar cell module may be any combination of the solar cell modules 100 or 110 and the solar cell strings 9a or 9b. Here, the third embodiment will be described as the configuration of the entire solar cell module conforms to the second embodiment.

(Cross-sectional structure of solar cell string)
The cross-sectional structure of the solar cell string 9c in the third embodiment is shown in FIG. The copper diffusion prevention sheet 1 is disposed on the copper wiring member 3 a via the first adhesive 2. Further, the copper wiring member 3 a is fixed on the collector electrode 5 formed on the solar battery cell 8 via the second adhesive 4. Such a configuration is the same as that of the second embodiment.

  Here, the surface state and the cross-sectional shape of the copper diffusion prevention sheet 1 will be described. First, the copper diffusion prevention sheet 1 is provided with the first adhesive 2 on one side, and metal is vapor-deposited on the surface on the side opposite to the side provided with the first adhesive 2 and has light diffusing ability. That is, when arranging the copper diffusion prevention sheet 1, the surface having light reflectivity is arranged toward the incident surface side of sunlight.

The cross-sectional shape of the surface having light reflectivity is reflected so that the direction of light incident from the upper vertical direction on the copper diffusion prevention sheet 1 is changed, and between the sealing material 6 a and the surface side protection member 10 or There is no limitation as long as it is a shape that can partially return incident light into the solar cell module by re-reflection between the side protection member 10 and the atmosphere. As shown in FIG. 9, it is preferable that a plurality of protrusions 7 having light diffusion ability be provided along the longitudinal direction of the copper diffusion prevention sheet 1. The number and shape of the plurality of protrusions 7 is not particularly limited, but it is preferably a plurality of continuous rectangles or a plurality of continuous semicircles, and most preferably a plurality of continuous triangles. The copper diffusion prevention sheet 1 and the projections 7 may be integrally molded, or may be formed by laminating the portions of the projections 7 after the copper diffusion prevention sheet 1 is formed.

  Although the embodiments according to the present invention have been described above in detail based on the drawings, the scope of the present invention is limited only by the claims described in the appended claims, and the embodiment described Is just an example. It should be understood that those skilled in the art can implement various modifications without departing from the spirit and scope of the present invention.

  For example, as the copper wiring members 3a and 3b, a copper core wire coated with a conductive material such as solder or silver is mainly used, but a wiring member consisting only of uncoated copper is used May be Even if a copper core wire is coated with a conductive material such as solder or silver, copper ions diffuse in the coating material and elute into the sealing material, so the embodiment of the present invention takes copper. Elution of ions can be suppressed. In the case of the wiring material consisting only of copper which is not coated, the effect is further enhanced because the elution of copper ions is severer compared to the coated copper wiring materials 3a and 3b.

  In the present embodiment, the copper diffusion prevention sheet 1 is used only on the copper wiring member 3a on the surface on which sunlight is incident, but in the double-sided power generation type solar cell module, the light incident surface is used. You may apply on the copper wiring material 3a arrange | positioned on the surface opposite to a side.

  1: Copper diffusion prevention sheet, 2: first adhesive, 3a, 3b: copper wiring material, 4: second adhesive, 5: collecting electrode, 6a, 6b: sealing material, 7: projection, 8: Solar cell, 9a, 9b, 9c: solar cell string, 10: front side protective member, 20: rear side protective member, 30: frame, 100, 110: solar cell module

Claims (2)

A first solar cell,
A second solar cell adjacent to the first solar cell;
A first copper wiring member for electrically connecting the light receiving surface of the first solar cell and the back surface of the second solar cell;
A second copper wiring member electrically connected to the light receiving surface of the second solar battery cell;
A sealing material for sealing the first solar battery cell, the second solar battery cell, the first copper wiring member, and the second copper wiring member;
And a copper diffusion prevention sheet disposed on the light receiving surface side of the first solar battery cell and the second solar battery cell and covering upper surfaces and side surfaces of the first copper wiring material and the second copper wiring material,
The said copper diffusion prevention sheet is a solar cell module arrange | positioned across the light receiving surface of a said 1st photovoltaic cell, and the light receiving surface of a said 2nd photovoltaic cell. The solar cell module according to claim 1 , wherein the copper diffusion preventing sheet has a light diffusing ability on at least one surface.

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