JP3433161B2 - Method of manufacturing solar cell module - Google Patents

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, and more particularly to a technology for manufacturing a solar cell module using a metal plate as a back member.

[0002]

2. Description of the Related Art A solar cell that uses solar energy to generate power is expected to be used in a wide range from general households to large-scale power generation as a clean and non-depleting energy source.

In particular, the use on a building roof is expected as a means for effectively utilizing a limited space. Above all, a building material integrated solar cell module integrated with a building material roof does not require a pedestal and is installed. It is particularly promising because it can significantly reduce construction costs.

[0004] building-integrated photovoltaic module typically copper, aluminum alloy plate, a lead plate, a zinc plate, a titanium plate, stainless steel plate, galvanized steel plate, zinc - aluminum alloy plated steel plate special plated steel plate such as, Laminated / coated steel
A solar cell is manufactured by bonding a solar cell on a back member made of a metal plate such as a plate.

A conventional method of manufacturing a solar cell module will be described with reference to FIGS. 4 and 5.

First, referring to the exploded sectional view shown in FIG.
In the conventional method of manufacturing a solar cell module, heat such as EVA (ethylene vinyl acetate copolymer), EEA (ethylene-acrylate copolymer resin) or PVB (polyvinyl butyral) is placed on the back surface member 1 made of a metal plate. A first encapsulant sheet 2 made of a plastic resin, and a plurality of crystalline semiconductor materials such as single crystal Si or polycrystalline Si or compound semiconductor materials such as GaAs electrically connected by a wiring material (not shown). The solar cell 3, the second sealing material sheet 4 made of a thermoplastic resin, and the surface member 5 made of a light-transmitting material such as glass or a plastic plate.
Are sequentially arranged to form the laminated body 10. Then, using a well-known laminating apparatus, this laminated body is heated to 100 ° C to 15 ° C.
It is heated to a temperature of 0 ° C. and pressure is applied in the laminating direction.

By this laminating step, the first and second sealing material sheets 2 and 4 are softened and integrated as shown in the sectional view of FIG. A plurality of solar cells 3 ... Are sealed and integrated between the back surface member 1 and the front surface member 5 by the sealing layer 6.
Next, the integrated laminated body is held in a thermostatic chamber and heat-treated at a temperature of about 150 ° C. for about 1 hour to crosslink the thermoplastic resin forming the sealing layer 6 to make a solar cell module. Is manufactured.

[0008]

As mentioned above, the solar cell module is manufactured in a heated state. Therefore, when a metal plate is used as the back member, the coefficient of thermal expansion thereof is larger than that of the front member made of glass, plastic, or the like, so that the back member is warped.

FIG. 6 is an enlarged sectional view of an essential part showing an enlarged end portion of the solar cell module after manufacturing. As shown in FIG. 6, the back surface member 1 is warped in a direction in which the front surface member side is convex. , The front surface member 5 and the back surface member 1 at the module end.
The distance between them increases. For this reason, the adhesive strength of the sealing layer 6 is reduced at the end of the module, and in extreme cases, a part 11 where the sealing layer 6 is partially peeled may occur. For this reason, moisture easily enters from the end of the module, which lowers long-term reliability and also causes the sealing layer 6
If some of them peeled off, the appearance was also poor. Further, such a problem is further increased because the warp due to the weight of the metal plate increases as the area of the solar cell module increases.

The present invention has been made in view of such conventional problems, and when a metal plate is used for the back member,
It is intended to provide a manufacturing method capable of manufacturing a solar cell module having improved reliability and a good appearance.

[0011]

In order to solve the above conventional problems, the manufacturing method of the present invention is a method of manufacturing a solar cell module in which a solar cell is sealed between a front surface member and a back surface member. Then, the solar cell and the front surface member are arranged on the back surface member via a sealing material sheet to form a laminated body, and the laminated body is formed by applying pressure in the laminating direction in a heated state to the laminated body. And a cross-linking step of performing a cross-linking reaction of the thermoplastic resin material forming the encapsulant sheet by heat treatment, in the outer peripheral part of the laminate, in the outer peripheral part of the laminate. Holding with a holder for keeping the distance between the front surface member and the back surface member constant, performing the bridging step, and holding a holding portion provided so as to sandwich the outer peripheral portion of the laminated body as the holder. Ingredient or laminated Characterized by using the adhesive tape from the surface member at the outer peripheral portion of the provided across the rear surface member.

[0012]

[0013]

[0014]

Further, according to the present invention, the back member has a flat plate portion, and a rising portion and a falling portion provided on each of a pair of opposite sides of the flat plate portion, and the rising portion of the back surface member. The cross-linking step is performed in a state in which the holder is attached to a side that does not include a portion and a falling portion.

Furthermore, the distance between the front surface member and the back surface member at the outer peripheral portion of the laminated body is ± 0.5 of the thickness of the laminated body before the laminating step by the holding tool.
It is characterized in that it is kept within mm.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described with reference to FIG.
In the figure, the same parts as those in FIG.

First, similarly to FIG. 4, a first sealing material sheet 2 made of EVA is formed on a back surface member 1 made of a metal plate.
Single crystal S electrically connected by wiring material not shown
a plurality of solar cells 3 made of i ..., a second made of EVA
The sealing material sheet 4 and the surface member 5 made of a glass plate are sequentially arranged to form a laminated body 10.

Next, as shown in FIG. 1, the holder 21 is attached to the outer peripheral portion of the laminated body 10. The holder 21 has a U-shaped cross section, and by sandwiching the back surface member 1 and the front surface member 5 in the outer peripheral portion of the laminated body 10 by the holding portion 21A, the back surface member 1 and the front surface member 5 in the laminated body 10 are sandwiched.
The distance between them is maintained at the inner height of the sandwiching portion 21A. Then, in this state, the laminated body is heated to a temperature of 100 ° C. to 150 ° C. and pressure is applied in the laminating direction. The holder 21 is preferably attached to four sides of the laminated body 10, but may be attached to at least two opposite sides.

By the laminating process, the first and second encapsulating material sheets 2 and 4 are softened and integrated as shown in FIG. 2, and the encapsulating material comprising EVA forming the encapsulating material sheets 2 and 4 is sealed. A plurality of solar cells 3 ... Are sealed and integrated between the back surface member 1 and the front surface member 5 by the layer 6.

Next, the integrated laminate is held in a constant temperature bath and heat-treated at a temperature of about 150 ° C. for about 1 hour to crosslink the EVA constituting the encapsulating layer 6 and to make a solar cell. The module is manufactured.

In the present invention, as described above, the laminated body 1
By sandwiching the outer peripheral portion of 0 with the sandwiching portion 21A of the holder 21, the distance between the back surface member 1 and the front surface member 5 is kept constant during the laminating step and the bridging step. Therefore,
According to the present invention, it is possible to reduce the warp of the back surface member 1 that occurs after the module is manufactured, and it is possible to suppress the decrease in the adhesive force or the peeling of the encapsulating material 6 that have been conventionally generated, and thus the excellent reliability is obtained. Thus, it becomes possible to manufacture a solar cell module having a good appearance.

In the present invention, the holder 21 is preferably made of a material having a small heat capacity, and is preferably made of metal, for example.

In the above embodiment, the holder 21 was attached to the laminate 10 during the laminating step, but since the transition from the laminating step to the crosslinking step is carried out quickly, the temperature change during this period is small, and the back surface is also small. The warpage of the member occurs when the temperature falls from the high temperature state to the room temperature state. Therefore, the effect of the present invention can be obtained by performing at least the crosslinking step with the holder attached.

(Embodiment 1) Next, an embodiment of the present invention will be described.

In this embodiment, the size of the back member is 13
Using steel plate having a thickness of 0.5mm at 300 mm × 250 mm,
A first EVA sheet, a plurality of solar cells made of single crystal Si, a second EVA sheet, and a surface member made of a glass plate were arranged on the back surface member to form a laminated body. In addition, the thickness of the whole laminated body at this time is about 4.7 mm.

Next, holders were attached to the four sides of this laminate. As the holder, a holder having a U-shaped cross-section and having an inner height of the sandwiching portion of 4.7 mm, which is the same as the thickness of the entire laminate, was used. Then, a solar cell module was manufactured by performing a laminating step and a cross-linking step with the holder attached, and this module was designated as Sample 1. In addition, a laminating step was performed in a state where the holder was not attached, and then the above-mentioned holder was attached and a crosslinking step was performed to manufacture a solar cell module, and this module was used as Sample 2. Furthermore, a solar cell module is manufactured by performing a laminating step and a crosslinking step without attaching a holder,
This module was used as a comparative sample. Then, as a result of visually observing the outer peripheral portions of the samples 1 and 2 and the comparative sample, a large number of locations where EVA was peeled off were present in the outer peripheral portion of the comparative sample. On the other hand, in the module of sample 1, no peeled off parts of EVA were observed, and in the module of sample 2, EV was not found at the four corners.
Only the part where A was peeled off was observed. Therefore, according to the present invention, it has been found that a solar cell module having excellent reliability and good appearance can be manufactured.

(Embodiment 2) Next, as the above-mentioned holder, it has a U-shaped cross-section as in Embodiment 1, and the inner heights of the holding portions are 4.2 mm, 4.0 mm and 5.2 mm, respectively. And 5.
Four types of holders having a length of 4 mm were used, and these holders were attached to the outer peripheral portion of the laminate to perform a laminating step and a crosslinking step, thereby manufacturing four types of solar cell modules. These modules were respectively sample 4 (the inner height of the clamping portion is 4.2 mm), sample 5 (the inner height of the retaining portion is 4.0 mm), sample 6 (the inner height of the retaining portion is 5.2 m).
m), and sample 7 (inside dimension height of the clamping portion 5.4 mm)
Then, as a result of visually observing the outer peripheral portion of each sample, in the samples 4 and 6, as in the case of the above-described sample 1, no peeled-off portion of EVA was observed.

However, in Sample 5, since the inner height of the holding portion (4.0 mm) in the holder used was considerably smaller than the thickness of the entire outer peripheral portion (4.7 mm), the outer peripheral portion of the laminate was It could not be completely inserted into the holder, creating a gap. Therefore, an extra external force is applied to the outer peripheral portion of the laminate, which rather promotes the outflow of EVA. For this reason, during the laminating step and the crosslinking step, EVA having a softened state and having a reduced viscosity flows out to the outside of the laminate, and a portion where EVA does not exist is generated.

On the contrary, with respect to the sample 7, the inner height (5.4 m) of the holding part in the holder used was 5.4 m.
Since m) was too large than the thickness of the laminate (4.7 mm), the warp of the back surface member could not be suppressed, and the EVA peeled off portion was generated.

From the above results, it was found that the holder for keeping the distance between the back surface member and the surface member constant is preferably the holder for keeping the thickness within ± 0.5 mm of the thickness of the laminate before lamination.

(Second Embodiment) In the above-described embodiments, the solar cell module using the flat plate-shaped back surface member has been described, but in this embodiment, the rising portion and the falling portion are used. A solar cell module using a back surface member having is described.

FIG. 3 is a perspective view showing the appearance of the solar cell module according to this embodiment. As shown in the figure, the back surface member 1 has a flat plate portion 1A, a rising portion 1B provided at the upper portion of the flat plate portion 1A, and a falling portion 1C provided at the lower portion thereof. Downlink 1C
An engaging portion that engages with each other is formed at the tip of the.

In the back member 1, the side on which the rising portion 1B and the falling portion 1C are formed is stronger in strength than other sides due to the existence of the rising portion 1B and the falling portion 1C, and is thermally deformed. It has a difficult structure. Therefore, when such a back surface member 1 is used, as shown in FIG. 3, by providing the holders 21 only on two sides where the rising portions 1B and the falling portions 1C are not formed, it is possible to realize the first embodiment. The same effect can be achieved.

As described above, according to the present invention, the laminated body is formed on the outer surface of the laminated body formed by disposing the solar cell and the front surface member on the back member with the encapsulating material sheet interposed therebetween. Since the bridging step is performed in a state where the holder for keeping the distance between the front surface member and the rear surface member in the outer peripheral portion constant, is attached, it is possible to suppress the warpage of the rear surface member made of a metal plate, which is excellent in reliability and appearance. A good solar cell module can be manufactured.

In the above embodiment, an example using a solar cell made of a crystalline semiconductor has been described.
Needless to say, the present invention can be applied not only to this but also to the case where a solar cell made of an amorphous semiconductor is used.

Further, the holder is not limited to the one having the above-described U-shaped cross-section, and any holder may be used as long as the distance between the front surface member and the rear surface member can be kept constant. . For example, the outer peripheral portion of the product layer body by sticking an adhesive tape over the surface member from the back member, the distance between the surface member and the back member in the crosslinking process may be kept constant. In this case, the adhesive tape corresponds to the holder of the present invention. The adhesive tape in this case may be made of any material as long as it can withstand a thermal process at 150 ° C. for about 1 hour.

[0038]

As described above, according to the present invention, it is possible to manufacture a solar cell module having excellent reliability and good appearance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view before a laminating step in a manufacturing method according to the present invention.

FIG. 2 is a cross-sectional view after a laminating step in the manufacturing method according to the present invention.

FIG. 3 is a perspective view for explaining the manufacturing method according to the second embodiment of the present invention.

FIG. 4 is an exploded cross-sectional view for explaining the method for manufacturing the solar cell module.

FIG. 5 is a cross-sectional view for explaining the method for manufacturing the solar cell module.

FIG. 6 is an enlarged sectional view of an essential part for explaining a conventional problem.

[Explanation of symbols]

1 ... Back surface member, 2, 4 ... Encapsulating material sheet, 3 ... Solar cell,
5 ... Surface member, 6 ... Sealing layer, 21 ... Holder, 21A ...

Claims (4)

(57) [Claims] 1. A method of manufacturing a solar cell module, in which a solar cell is sealed between a front surface member and a back surface member, wherein the solar cell and the front surface are provided on the back surface member via a sealing material sheet. Laminating step in which members are arranged to form a laminated body, and the laminated body is integrated by applying pressure to the laminated body in a laminating direction in a heated state; and thermoplasticity that constitutes the encapsulant sheet by heat treatment. A cross-linking step of performing a cross-linking reaction of the resin material, and, in a state where a holder for keeping a constant distance between the front surface member and the back surface member in the outer peripheral portion of the laminate is attached to the outer peripheral portion of the laminate, performs the crosslinking process, as the holder, the method for manufacturing the solar cell module, which comprises using a holder having a clamping portion provided so as to sandwich the outer peripheral portion of the laminate. 2. A solar cell is provided between the front surface member and the back surface member.
A method of manufacturing a solar cell module obtained by encapsulating, wherein the solar cell is provided on the back surface member via an encapsulating material sheet.
And the surface member are arranged to form a laminated body, and the laminated body is applied.
By applying pressure in the stacking direction in the heat state,
Thermoplastic resin that constitutes the encapsulant sheet by a laminating step of integration and heat treatment
Has a cross-linking step for cross-linking reaction of the material, and the outer peripheral portion of the laminate, the table in the outer peripheral portion of the laminate
Mounts a holder that keeps the distance between the front and back members constant.
While performing the crosslinking step in a state of being welded, as the holder, the front surface in the outer peripheral portion of the laminate.
Use an adhesive tape that extends from the face member to the back member
A method for manufacturing a solar cell module, which is characterized in that 3. The flat plate part and the flat plate part
In each of a pair of opposing sides in
And a falling portion, and in the back member
Attach the holder to the side that does not have a rising portion and a falling portion.
The method for manufacturing a solar cell module according to claim 1 or 2 , wherein the cross-linking step is performed in the attached state . 4. The outer peripheral portion of the laminate by the holder.
The distance between the front surface member and the back surface member in
Within ± 0.5 mm of the thickness of the laminate before the process
The method according to any one of claims 1 to 3, characterized in that
Method for manufacturing the mounted solar cell module.