JPH09312408A - Manufacture of solar battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a solar battery module which has a sufficient bond strength between bonded members and has good productivity. SOLUTION: A solar battery 9 is held between a first 2-layer film 7 formed at its one side on a thermoplastic elastomer layer 2 and a second 2-layer film 8 formed at its one side on a thermoplastic elastomer layer 2, heated, melted and softened in a vacuum atmosphere at normal temperature to tightly bond both elastomer layers and solar battery cell, and then the atmosphere is returned to the atmosphere to set and seal the solar battery 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solar cell module mainly used for electric power.

[0002]

2. Description of the Related Art A solar cell, which is a device that directly converts solar energy into electric energy, can extract necessary unit power from its terminals, has environmental resistance to withstand long-term use, and is easy to handle as a unit. Due to needs such as goodness, it is used as a so-called solar cell module in which solar cells are packaged. Among such solar cell modules, super straight type modules are often used for power modules because of their demands for reliability, environmental resistance, and low cost.

Generally, as shown in FIG. 8, the superstrate type solar cell module has EVA (ethylene vinyl acetate), PVB (polyvinyl) below the transparent glass plate 40 disposed on the light receiving surface side. A transparent adhesive resin 41 such as butyral) in which solar cells 42 connected in series or in parallel are encapsulated and bonded, and a moisture-proof sheet 43 for preventing moisture from entering is further bonded to the lower side thereof. Has been done. In the figure, 4
Reference numeral 4 is a frame body attached to the peripheral portion via a rubber seal 45, and 46 is an output lead.

When manufacturing a super straight type solar cell module as described above, generally, an adhesive resin sheet 41a and a solar cell 4 are provided on a glass plate 40.
2, the adhesive resin sheet 41b and the moisture-proof sheet 43 are stacked in this order and heated under a reduced pressure atmosphere to produce the adhesive resin sheet 41.
A and 41b are melt-bonded and bonded together. Then, the glass plate 40 and the adhesive resin sheet 41
Conventionally, a single vacuum method and a double vacuum method have been performed as a method of bonding the bonding member 48 in which a, 41b, the solar cell 42, the moisture-proof sheet 43 and the like are stacked.

The above single vacuum system, as shown in FIG.
After the bonding member 48 is placed in a rubber bag 47 in a stacked state, the entire rubber bag 47 is heated while exhausting the inside to temporarily bond the adhesive resin sheets 41a, 41b, etc., The rubber bag 47 is placed in an autoclave, heated under atmospheric pressure and heated to be permanently bonded.

On the other hand, the double vacuum system uses an apparatus having two vacuum chambers 50 and 51 partitioned by a rubber diaphragm 49 as shown in FIG. The bonding member 48 is loaded, and first, the both vacuum chambers 50 and 51 are evacuated at the same time to bond the bonding member 4
8 is sufficiently evacuated between the members, and the inside of the upper vacuum chamber 51 is returned to the atmospheric pressure while heating the apparatus, so that the bonding member 48 is utilized by utilizing the force of the diaphragm 49 expanding into the lower vacuum chamber 50. Is applied from above to bond.

[0007]

However, although the single vacuum method is simple in terms of equipment, the rubber bag 47 is crushed at atmospheric pressure at the same time as the inside is evacuated, and the exhaust conductance is small. However, it has the drawback that deaeration above a certain level becomes difficult. Therefore, only a degree of vacuum of about tens of thousands Pa is obtained, and exhaust between the respective members of the bonding member 48 is not sufficiently performed. Further, since the stored gas inside the adhesive resin 41 cannot be sufficiently removed, there is a problem that the adhesive strength of the bonded product becomes insufficient.

On the other hand, in the above double vacuum system, a high degree of vacuum of several hundred Pa or less can be obtained, and the adhesive resin 41
Although the stored gas inside can be removed sufficiently and sufficient adhesive strength can be obtained, it becomes complicated in terms of equipment and
A rubber diaphragm 49 must be installed in the vacuum chambers 50 and 51 as a dedicated device for bonding. Therefore, there is a problem that the equipment cost becomes high. Further, since the bonding member 48 is pressed from above by the diaphragm 49 to apply pressure, it is not possible to stack a plurality of bonding members 48 to carry out the bonding process, so that the bonding member 48 can be loaded into the apparatus. The number of the bonding members 48 is limited. Therefore, there is also a problem that the amount of batch processing performed once is small and the productivity is extremely poor.

The present invention has been made in view of the above circumstances, and it is possible to sufficiently evacuate each member such as a solar battery cell to be bonded, to obtain a sufficient adhesive force, and to improve productivity. It is an object of the present invention to provide a good manufacturing method of a solar cell module.

[0010]

In order to achieve the above object, a method of manufacturing a solar cell module according to the present invention comprises a first two-layer film in which a thermoplastic elastomer layer is laminated on one surface of a cover film, A step of preparing a second two-layer film in which a thermoplastic elastomer layer is laminated and formed on one surface of a substrate film, and a step of mounting a solar battery cell on the thermoplastic elastomer layer of the second two-layer film , The thermoplastic elastomer layer of the second two-layer film is melted and softened by heating in a reduced pressure atmosphere to bring the mounted solar battery cells into close contact with each other, and then returned to an atmospheric pressure atmosphere, whereby the solar battery cells are And a thermoplastic elastomer layer, and a step of cooling and solidifying the melt-softened thermoplastic elastomer in a normal temperature atmosphere, Stacking the first two-layer film on the upper surface of the second two-layer film to which the battery cells are adhered so that the thermoplastic elastomer layers of both two-layer films face each other, and heating in a reduced pressure atmosphere After the two thermoplastic elastomer layers are melt-softened with each other to bring the two melt-softened thermoplastic elastomer layers into close contact with each other, and then to return to an atmospheric pressure atmosphere, the both thermoplastic elastomer layers and the both thermoplastic elastomer layers A step of adhering a solar cell sandwiched between these,
And a step of sealing the solar battery cell by cooling and solidifying both the thermoplastic elastomer layers in the melted and softened state under a normal temperature atmosphere.

[0011]

Next, an embodiment of the present invention will be described in detail.

According to the present invention, a first two-layer film is formed by laminating a thermoplastic elastomer layer on one side of a cover film, and a second two-layer film is formed by laminating a thermoplastic elastomer layer on one side of a substrate film. A solar cell module is manufactured using the film.

The solar cell used for the solar cell module is a single solar cell obtained by subjecting a wafer of single crystal silicon, polycrystalline silicon, amorphous silicon or the like to impurity diffusion treatment, electrode formation treatment, or the like.
Alternatively, it is used in the state of so-called cell strings connected in series or in parallel by connecting leads or the like. The specifications such as the connection state when forming the cell strings, the number of cell single products, and the size of the cell single products are appropriately selected according to the required unit power, application, cost, etc., and are not particularly limited. Not a thing. That is, in the present invention, the solar battery cell includes not only a single cell product but also a cell string.

The material of the cover film or the substrate film is not particularly limited as long as it does not melt or change in quality when heated, and various materials can be used. For example, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polycarbonate, cellulose acetate, saturated polyester, polyamide, polyimide, polysulfone, polyarylate, polyether sulfone, polyether ether ketone, polyether Imide, polyphenylene sulfide, TPX polymer, polyparaxylene, polyamide imide, polyester imide, polybenzimidazole, vinyl fluoride, acryl, phenol, polyurethane, epoxy resin, urea resin, melamine resin,
Various materials such as resin materials such as silicone, inorganic materials such as glass, ceramics, metal alkoxide, and metal materials such as aluminum and stainless are used. The cover film or substrate film may be used with a single material, or, like a moisture-proof sheet in which a conventionally used aluminum foil is sandwiched between vinyl fluoride films,
It may be a laminate of a plurality of types of sheets. In the present invention, the substrate film includes not only a flexible sheet-shaped film but also a plate-shaped one that can support a solar battery cell as a module substrate.

At least one of the substrate film and the cover film disposed on the light receiving surface side is required to be transparent in order to irradiate the solar cell with light. Here, in the present invention, “transparent” means JIS R
The value of visible light transmittance measured according to 3106 is 80.
% Or more. The light transmittance of the substrate film or the cover film is desired to be as high as possible in order to improve the photoelectric conversion efficiency, but in practice, it is preferably 85% or more. The other film provided on the opposite side of the light receiving surface of the solar cell module does not necessarily have to be transparent.

The above-mentioned thermoplastic elastomer is not particularly limited as long as it is a material which is transparent, melts and softens in a heated state and adheres to it, and does not deteriorate such as yellowing. For example, styrene type, vinyl chloride type, olefin type, polyester type, polyamide type,
Urethane type can be raised. Among these, in particular,
A non-yellowing type polyurethane elastomer is preferable because it has characteristics that it is melted and softened by heating at a relatively low temperature and adheres to it, and that it has excellent impact resistance. It is also preferable that this thermoplastic elastomer is transparent like the above-mentioned substrate film and cover film.

In the present invention, the above-mentioned solar battery cell, substrate film, cover film and thermoplastic elastomer are used to manufacture a solar battery module as follows.

First, as shown in FIG. 1, a thermoplastic elastomer layer 1 is previously laminated on one surface of the cover film 3 to form a first two-layer film 7. The method for laminating and forming the thermoplastic elastomer layer 1 is not particularly limited, and a thermo roll laminating method in which the thermoplastic elastomer layer 1 formed in a sheet shape in advance is laminated on one surface of the cover film and joined by a thermo roll, A cover film 3 that pushes out a molten film of a thermoplastic elastomer from a slit of an extruder and sends it from the front side.
Various methods such as an extrusion laminating method of laminating on top and cooling and solidifying, a dry laminating method of applying an adhesive on the cover film 3 and laminating and adhering the sheet-shaped thermoplastic elastomer layer 1 are performed. Here, the thickness of the thermoplastic elastomer layer 1 varies depending on the material of the thermoplastic elastomer, the thickness of the solar battery cell 9, and the like, but the solar battery cell 9 is completely sealed, and the durability against the impact from the outside is high. From the viewpoint of maintaining and not impairing the light transmittance, it is preferably set in the range of 100 to 1000 μm, and more preferably 200 to 500 μm.

Further, as shown in FIG. 2, the thermoplastic elastomer layer 2 is preliminarily laminated and formed on the substrate film 4 by various methods as described above to form the second two-layer film 8.

Then, as shown in FIG. 3, a second film 2 composed of the substrate film 4 and the thermoplastic elastomer layer 2 is formed.
The solar battery cell 9 is mounted on the thermoplastic elastomer layer 2 of the layer film 8. In the figure, 5 is a connection lead.

Then, the second two-layer film 8 on which the solar battery cells 9 are mounted is loaded into a vacuum heating device and evacuated. The degree of vacuum at this time is such that the air in the gap between the solar battery cell 9 and the thermoplastic elastomer layer 2 is sufficiently discharged, and the stored gas is discharged from the thermoplastic elastomer layer 2 or the like to improve the adhesiveness. Therefore, it is desirable to be as high as possible, but in practice, it is 100-500.
It is set to about Pa, more preferably about 100 to 200 Pa.

Next, after reaching a predetermined degree of vacuum, the inside of the vacuum heating device is heated to melt and soften the thermoplastic elastomer layer 2 and, as shown in FIG. The solar battery cells 9 mounted on the two-layer film 8 of No. 2 are brought into close contact with each other. The heating temperature and heating time at this time vary depending on the material of the thermoplastic elastomer layer 2 and the like, but the thermoplastic elastomer layer 2 is melted and softened so that the thermoplastic elastomer layer 2 and the solar cell 9 are sufficiently adhered to each other without leaving a gap. Can be set to temperature and time. In the figure, 6 is a vacuum heating device.

Next, after the thermoplastic elastomer layer 2 is sufficiently melted and softened so that the solar battery cells 9 and the thermoplastic elastomer layer 2 are sufficiently adhered to each other, air is introduced into the vacuum heating device 6 to change from vacuum to atmospheric pressure. The solar cell 9 and the thermoplastic elastomer layer 2 are utilized by utilizing the pressurizing action by the pulling pressure when returning.
And glue.

After that, the heater (not shown) of the vacuum heating device 6 is turned off, or the second two-layer film 8 to which the solar battery cells 9 are adhered is taken out from the vacuum heating device 6 or the like. By cooling at room temperature, the melted and softened thermoplastic elastomer layer 2 is cooled and solidified.

Then, as shown in FIG. 5, the second two-layer film 8 to which the solar battery cells 9 are adhered by the steps up to the above is carried out.
On top of which a cover film 3 and a thermoplastic elastomer layer 1
The first two-layer film 7 composed of and is laminated so that the thermoplastic elastomer layers 1 and 2 of the two two-layer films 7 and 8 face each other. As a result, the solar battery cell 9 is sandwiched between the two thermoplastic elastomer layers 1 and 2.

Then, the two laminated two-layer films 7 and 8 are loaded again into the vacuum heating device 6 and evacuated. Also in this evacuation, as in the case described above, air in the gap between the thermoplastic elastomer layer 1 of the first two-layer film 7 and the solar battery cells 9 is sufficiently exhausted, and at the same time, from within the thermoplastic elastomer layer 2 or the like. In order to discharge the occluded gas and improve the adhesiveness, vacuuming is performed up to a predetermined vacuum degree.

Next, after reaching a predetermined degree of vacuum, the inside of the vacuum heating device 6 is heated to melt and soften the both thermoplastic elastomer layers 1 and 2, and as shown in FIG.
The thermoplastic elastomer layer 1 of the layer film 7 and the thermoplastic elastomer layer 2 of the second two-layer film 8 are brought into close contact with each other. The heating temperature and the heating time at this time are set to a temperature and a time at which both the thermoplastic elastomer layers 1 and 2 are sufficiently melted and softened and the two thermoplastic elastomer layers 1 and 2 are adhered to each other so that no gap is left between them. To do.

Next, both thermoplastic elastomer layers 1, 2
Are sufficiently melted and softened and brought into close contact with each other, then air is introduced into the vacuum heating device 6 to return to atmospheric pressure. As shown in FIG. 7, the first two-layer film 7 and the first two-layer film 8 are utilized by utilizing the suction pressure when returning from the vacuum to the atmospheric pressure.
Is pressed to bond the two thermoplastic elastomer layers 1 and 2 to each other so as to be integrated with each other, and the both thermoplastic elastomer layers 1 and 2 and the solar battery cell 9 sandwiched therebetween are bonded to each other and integrated. The solar battery cell 9 is enclosed in the thermoplastic elastomer layer 10.

After that, the heater of the vacuum heating device 6 is turned off, or the two two-layer films 7 and 8 adhered to each other are removed from the vacuum heating device 6.
By taking it out from the inside and cooling it at room temperature,
The melted and softened thermoplastic elastomer layers 1 and 2 (that is, the integrated thermoplastic elastomer layer 10) are cooled and solidified, and the solar cell 9 sandwiched between them is sealed with the thermoplastic elastomer layer 10. .

A solar cell module can be manufactured by the series of steps described above. In the above description, the case where one solar cell module is attached in the vacuum heating device 6 has been described. However, the present invention is not limited to this. You may make it bond several solar cell modules by the batch process of. By doing so, the productivity can be extremely improved.

[0031]

As described above, in the method for manufacturing the solar cell module of the present invention, first, the second two-layer film having the solar cells mounted thereon is heated in a reduced pressure atmosphere to melt and soften the thermoplastic elastomer layer. The solar cells are brought into close contact with each other, and the solar cells are adhered by utilizing the pulling pressure when returning to atmospheric pressure. Then, the first two-layer film is laminated on the second two-layer film to which the solar cell is adhered, heated under a reduced pressure atmosphere, and then returned to atmospheric pressure, so that the sun sandwiched between the two thermoplastic elastomer layers. Seal the battery cells. For this reason, the gaps between the solar cell and the two-layer films and between the two-layer films can be sufficiently exhausted and bonded. Therefore, unlike the conventional single-vacuum system, the degree of vacuum is not insufficient and the adhesive strength is not insufficient, and high adhesive strength can be obtained. Further, various general-purpose devices can be used as long as they can heat the respective members to be bonded in a reduced pressure atmosphere.
Therefore, compared to the conventional double vacuum system, the equipment is simple and the equipment cost is low. In addition, since the pressure bonding is performed by utilizing the pulling pressure when returning from the reduced pressure atmosphere to the atmospheric pressure and the diaphragm is not used, it is possible to perform the bonding process in a state in which a plurality of layers are stacked in the apparatus.
Therefore, the amount of batch processing performed once increases, and the productivity is dramatically improved.

Next, examples will be described.

[0033]

Example The following materials were prepared and a solar cell module was manufactured according to the manufacturing process described above. The various conditions in the manufacturing process are shown below. [Various materials] Cover film: Material PVF size Thickness 0.050 mm x 100 mm x 120 mm Substrate film: Material PET size Thickness 0.175 mm x 100 mm x 120 mm Thermoplastic elastomer: Material Yellowing type transparent polyurethane elastomer Thickness 300 μm Visible light transmittance 88.8% Haze 1.7% Gloss 137% Solar cell: Polycrystalline silicon solar cell Dimensions 0.5mm × 97.5mm × 25.0mm Number of sheets 3 pieces Device connection 3 sheets in series Vacuum heating device: Vacuum oven: VAC, manufactured by Tabai Espec Co., Ltd. Internal dimensions 600 mm × 600 mm × 600 mm [Production conditions] Vacuum degree: 100 Pa for each heating temperature: 150 ° C. for each heating time: 60 minutes each Batch processing amount: 60 modules

By manufacturing the solar cell module as described above, it was possible to sufficiently evacuate the bonding members and to prevent defective adhesion. Also, 60 modules could be collectively processed in one batch processing, and the productivity was also good.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first two-layer film.

FIG. 2 is a sectional view showing a second two-layer film.

FIG. 3 is a cross-sectional view showing a state in which solar cells are mounted on a second two-layer film.

FIG. 4 is an explanatory view showing a state in which the second two-layer film on which the solar cells are mounted is subjected to vacuum heat treatment.

FIG. 5 is a cross-sectional view showing a state in which a first two-layer film is laminated on a second two-layer film to which solar cells are adhered.

FIG. 6 is an explanatory diagram showing a state in which the two laminated two-layer films are heat-treated under vacuum.

FIG. 7 is an explanatory diagram showing a state in which the atmospheric pressure is restored after the vacuum heat treatment.

FIG. 8 is a cross-sectional view showing a conventional solar cell module.

FIG. 9 is a cross-sectional view showing a step of attaching a conventional solar cell module.

FIG. 10 is a cross-sectional view showing another bonding step of the conventional solar cell module.

[Explanation of symbols]

 1, 2 thermoplastic elastomer layer 3 cover film 4 substrate film 7 first two-layer film 8 second two-layer film 9 solar cell

Claims (1)

[Claims] 1. A first two-layer film in which a thermoplastic elastomer layer is laminated on one surface of a cover film,
A step of preparing a second two-layer film in which a thermoplastic elastomer layer is laminated on one surface of the substrate film;
The step of mounting a solar battery cell on the thermoplastic elastomer layer of the second two-layer film, and the thermoplastic elastomer layer of the second two-layer film is melted and softened by heating in a reduced pressure atmosphere to mount the solar cell. After adhering the solar cells adhered to each other, a step of adhering the solar cells and the thermoplastic elastomer layer by returning to the atmospheric pressure atmosphere, and cooling and solidifying the thermoplastic elastomer in the melt-softened state under normal temperature atmosphere And the first two layers on the upper surface of the second two-layer film to which the solar cell is adhered.
A step of laminating the two-layer film so that the thermoplastic elastomer layers of the two-layer films face each other, and the two thermoplastic elastomer layers are melt-softened by heating in a reduced pressure atmosphere to melt and soften the two thermoplastic elastomer layers. After bringing them into close contact with each other, a step of adhering the both thermoplastic elastomer layers and the both thermoplastic elastomer layers and the solar battery cells sandwiched between them by returning to the atmospheric pressure atmosphere, and the melting and softening under normal temperature atmosphere And a step of sealing the solar battery cells by cooling and solidifying both the thermoplastic elastomer layers in the state, and a method for manufacturing a solar battery module.