WO2021095217A1

WO2021095217A1 - Solar cell panel, solar cell module, method for manufacturing solar cell panel, and method for manufacturing solar cell module

Info

Publication number: WO2021095217A1
Application number: PCT/JP2019/044783
Authority: WO
Inventors: 高好松田
Original assignee: 三菱電機株式会社
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2021-05-20

Abstract

In a solar cell panel (10), a solar cell string (3a), in which a plurality of solar cells (3) are electrically connected, is sealed within a seal layer (6) sandwiched between a light-receiving-side protective member and a back-side covering member (5). The seal layer (6) is provided with: a light-receiving-side seal layer (2) that is formed from a polyolefin-based resin and that covers the entire light-receiving side of the solar cell string (3a); and a back-surface-side seal layer (4) that is formed from an ethylene vinyl acetate copolymer resin, that covers the solar cell string (3a) from the back side of the solar cell string (3a), and that covers the light-receiving-side seal layer (2) from the back side of the light-receiving-side seal layer (2) and from the outer peripheral side of the light-receiving-side seal layer (2).

Description

Solar cell panel, solar cell module, solar cell panel manufacturing method and solar cell module manufacturing method

The present invention relates to a solar cell panel, a solar cell module, a method for manufacturing a solar cell panel, and a method for manufacturing a solar cell module in which a solar cell is sealed with a sealing material made of a resin material.

Conventionally, one of the manufacturing techniques for solar cell panels is to seal the light-receiving surface side made of ethylene-vinyl acetate copolymer (EVA) resin on a light-transmitting substrate made of tempered glass or the like. There is a technique of mounting and laminating a back surface side sealing layer and a back surface side covering member composed of a layer, a solar cell, and EVA.

At the time of manufacturing a solar cell panel, a light transmitting substrate having light transmission, a light receiving surface side sealing layer made of a light transmitting insulating resin, a solar cell, a back surface side sealing layer and a back surface side covering member are sequentially formed. A laminated body is formed. Then, the solar cell is sealed in the sealing layer by performing the laminating process of the laminated body in the laminating device. In the laminating apparatus, the EVA is melted and cured by heating and pressurizing the laminated body, and the solar cell is sealed. The light receiving surface side sealing layer and the back surface side sealing layer are members necessary for ensuring the insulating performance in addition to the sealing performance.

In recent years, olefin resins have been increasingly used as sealing materials for solar cell panels. Patent Document 1 discloses that a polyolefin resin is used as a sealing material. The amount of acid generated in the polyolefin resin over time is smaller than that in EVA. Therefore, by using the polyolefin-based resin as the encapsulant, it is possible to delay the deterioration of the conductive portion sealed in the encapsulant due to the acid generated in the encapsulant. As a result, deterioration of the output of the solar cell panel over time can be suppressed.

Japanese Patent No. 5838321

However, when a polyolefin resin is used as a sealing material as in the solar cell module described in Patent Document 1, there is a concern that the insulating property of the sealing layer may be lowered due to hydrolysis of the polyolefin resin due to long-term use. Will be done.

The present invention has been made in view of the above, and an object of the present invention is to obtain a solar cell panel in which output deterioration and deterioration of the insulating property of the sealing layer due to aged use are suppressed.

In order to solve the above-mentioned problems and achieve the object, in the solar cell panel according to the present invention, the solar cell strings in which a plurality of solar cells are electrically connected are placed on the light receiving surface side of the solar cell strings. The sun sealed in a sealing layer sandwiched between the light-receiving surface side protective member arranged and the light-receiving surface of the solar cell strings and the back surface side covering member arranged on the back surface side facing back. It is a battery panel. The sealing layer is composed of a polyolefin-based resin and a light-receiving surface side sealing layer that covers the entire surface of the solar cell cell strings on the light-receiving surface side, and an ethylene-vinyl acetate copolymer resin. In addition to covering from the back surface side of the cell strings, the back surface side sealing layer that covers the light receiving surface side sealing layer from the back surface side of the light receiving surface side sealing layer and the outer peripheral side of the light receiving surface side sealing layer is provided.

The solar cell panel according to the present invention has the effect of being able to suppress output deterioration and deterioration of the insulating property of the sealing layer due to long-term use.

Schematic cross-sectional view showing the solar cell module according to the first embodiment of the present invention. Schematic plan view showing the solar cell panel of the solar cell module according to the first embodiment of the present invention. Schematic sectional view showing a solar cell panel of the solar cell module according to the first embodiment of the present invention. Schematic cross-sectional view showing a holding frame of the solar cell module according to the first embodiment of the present invention. A flowchart showing a procedure of a method for manufacturing a solar cell module according to a first embodiment of the present invention. An exploded perspective view showing the configuration of the solar cell panel according to the first embodiment of the present invention before laminating. Sectional drawing which shows the structure of the laminated body before laminating in the manufacturing process of the solar cell panel which concerns on Embodiment 1 of this invention. Schematic cross-sectional view showing a solar cell panel manufacturing apparatus used for manufacturing the solar cell panel according to the first embodiment of the present invention. Schematic cross-sectional view showing a solar cell panel manufactured by the method for manufacturing a solar cell panel according to the first embodiment of the present invention. The figure which shows the preparation condition of the sample of Example 1, Comparative Example 1 and Comparative Example 2. The figure which shows the measurement result of the sample of Example 1, Comparative Example 1 and Comparative Example 2.

Hereinafter, the solar cell panel, the solar cell module, the method for manufacturing the solar cell panel, and the method for manufacturing the solar cell module according to the embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment, and can be appropriately modified without departing from the gist of the present invention. Further, in the drawings shown below, the scale of each member may differ from the actual scale for easy understanding.

Embodiment 1.
FIG. 1 is a schematic cross-sectional view showing a solar cell module 50 according to a first embodiment of the present invention. FIG. 2 is a schematic plan view showing the solar cell panel 10 of the solar cell module 50 according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing the solar cell panel 10 of the solar cell module 50 according to the first embodiment of the present invention. FIG. 3 shows a cross section along lines III-III in FIG. FIG. 4 is a schematic cross-sectional view showing a holding frame 20 of the solar cell module 50 according to the first embodiment of the present invention.

The solar cell panel 10 according to the present embodiment has a light receiving surface side sealing layer made of a light transmitting insulating resin on a light transmitting substrate 1 which is a light receiving surface side protective member arranged on the light receiving surface side. 2, a solar cell string 3a to which a plurality of solar cells 3 which are photovoltaic elements are electrically connected, a back surface side sealing layer 4, and a back surface arranged on the back surface side facing the light receiving surface. It has a structure in which the side covering member 5 and the side covering member 5 are sequentially laminated. In the solar cell panel 10, the solar cell strings 3a are arranged on the light-receiving surface side protective member arranged on the light-receiving surface side of the solar cell strings 3a and on the back surface side facing the light-receiving surface of the solar cell strings 3a. It is sealed in a sealing layer 6 sandwiched between the back surface side covering member 5. In the solar cell panel 10, the sunlight L is incident from the surface side of the light transmissive substrate 1.

The solar cell panel 10 has a quadrangular outer shape in the in-plane direction of the solar cell panel 10. In the first embodiment, the solar cell panel 10 has a rectangular outer shape in the in-plane direction of the solar cell panel 10. The direction parallel to the pair of opposite sides in the rectangular shape of the outer shape of the solar cell panel 10 is defined as the first direction. In FIG. 1, the first direction corresponds to the X direction. The direction parallel to the other pair of opposing sides in the rectangular shape of the outer shape of the solar cell panel 10 is defined as the second direction. In FIG. 1, the second direction corresponds to the Y direction.

The light transmissive substrate 1 is fixed to the outer surface of the light receiving surface side sealing layer 2 having a two-layer structure located on the light receiving surface side in the solar cell panel 10 by the adhesive force of the light receiving surface side sealing layer 2. Has been done. Sunlight L is incident on the surface of the light transmissive substrate 1. As the light-transmitting substrate 1, a glass substrate having light-transmitting property and weather resistance is used. Although a glass substrate is used as the light-transmitting substrate 1 here, another member such as a resin plate may be used as long as it is a material having light-transmitting property and weather resistance. However, it is preferable to use a glass substrate when there is a concern that the insulating property may be deteriorated due to hydrolysis of the resin due to long-term use.

The light transmissive substrate 1 has a quadrangular outer shape in the in-plane direction of the light transmissive substrate 1 as well as the outer shape in the in-plane direction of the solar cell panel 10. The in-plane direction of the light transmissive substrate 1 is parallel to the in-plane direction of the solar cell panel 10. In the first embodiment, the light transmissive substrate 1 has a rectangular outer shape in the in-plane direction of the light transmissive substrate 1, similarly to the solar cell panel 10.

Here, in the external dimensions of the light transmissive substrate 1, the dimension in the first direction, that is, the dimension in the X direction is X1, and the dimension in the second direction, that is, the dimension in the Y direction is Y1. The external dimensions of the light transmissive substrate 1 in this case are represented by (X1, Y1).

The light receiving surface side sealing layer 2 is mainly on the light transmitting substrate 1 side of the light receiving surface of the solar cell 3 of the solar cell strings 3a among the sealing layers 6 for sealing the solar cell strings 3a inside. The area where it was placed. Further, the back surface side sealing layer 4 is mainly on the back surface side covering member 5 side of the back surface side of the solar cell 3a of the solar cell strings 3a among the sealing layers 6 for sealing the solar cell strings 3a inside. The area where it was placed. The back surface of the solar cell 3 is a surface facing the light receiving surface of the solar cell 3 in the solar cell 3.

The light-receiving surface side sealing layer 2 is a region of the solar cell panel 10 on the light-transmitting substrate 1 side of the light-receiving surface of the solar cell 3, and a light-transmitting substrate 1 side on the outside of the outer periphery of the solar cell strings 3a. Is arranged in the region of the above, and in the region on the light transmissive substrate 1 side of the gap region between the solar cells 3 in the solar cell strings 3a. The light receiving surface side sealing layer 2 covers the solar cell cell strings 3a from the light receiving surface side and the outer peripheral side of the solar cell cell strings 3a, and seals the solar cell cell strings 3a together with the back surface side sealing layer 4. There is. That is, the light receiving surface side sealing layer 2 covers the entire surface of the solar cell strings 3a on the light receiving surface side. As the light receiving surface side sealing layer 2, a single layer or a laminated body of a thermoplastic resin in which a cross-linking agent is added to a light-transmitting polyolefin resin such as polyethylene and polypropylene is used. Polyolefin-based resins generate relatively less acid than EVA. Further, the light receiving surface side sealing layer 2 improves weather resistance, mechanical strength, adhesiveness to the light transmissive substrate 1, adhesiveness to the solar cell strings 3a, and adhesiveness to the back surface side sealing layer 4. It is preferable that they are cross-linked to allow them to be cross-linked. As a method for cross-linking, a conventionally known method can be used, but a method that generates radicals by heat is effective.

Further, the light receiving surface side sealing layer 2 preferably contains an ultraviolet absorber in order to improve the light resistance. However, since the ultraviolet absorber is contained in the light receiving surface side sealing layer 2, the amount of sunlight L incident on the solar cell 3 is reduced, and the output of the solar cell 3 is reduced. Therefore, it is preferable that the content of the ultraviolet absorber in the light receiving surface side sealing layer 2 is adjusted according to the design life of the solar cell 3.

Further, in the first embodiment, the thickness of the light receiving surface side sealing layer 2 is preferably 0.05 mm or more and 1.0 mm or less. In the first embodiment, the light receiving surface side sealing layer 2 uses a polyolefin resin having a thickness T = 0.05 mm or more and 1.0 mm or less. The melt flow rate (Melt Flow Rate: MFR) of the polyolefin resin used for the light receiving surface side sealing layer 2 is 0.1 g / 10 min or more and 35 g / 10 min or less. By setting the melt flow rate of the polyolefin resin used for the light receiving surface side sealing layer 2 within the above range, it is possible to prevent the solar cell 3 from being damaged by an external force applied to the solar cell 3 during the manufacture of the solar cell panel 10. be able to. MFR means the melt flow rate described in JIS K 7210-1: 2014.

Further, by setting the melt flow rate of the polyolefin resin used for the light receiving surface side sealing layer 2 within the above range, the flow of the polyolefin resin during the manufacture of the solar cell panel 10 is controlled and the light receiving surface side sealing layer is controlled. 2 can be thinned. By thinning the light-receiving surface side sealing layer 2, it is possible to increase the amount of sunlight L transmitted through the light-receiving surface side sealing layer 2 and improve the output of the solar cell 3.

Here, in the external dimensions of the light receiving surface side sealing layer 2, the dimension in the first direction, that is, the dimension in the X direction is X2, and the dimension in the second direction, that is, the dimension in the Y direction is Y2. The external dimensions of the light receiving surface side sealing layer 2 in this case are represented by (X2, Y2). Here, X2 is shorter than X1 and Y2 is shorter than Y1. That is, the external dimensions (X2, Y2) of the light receiving surface side sealing layer 2 are smaller than the external dimensions (X1, Y1) of the light transmissive substrate 1. Therefore, the outer shape of the light receiving surface side sealing layer 2 is smaller than the outer shape of the light transmissive substrate 1.

The solar cell strings 3a are sealed between the light transmissive substrate 1 and the back surface side covering member 5 in the light receiving surface side sealing layer 2 and the back surface side sealing layer 4. In the solar cell strings 3a, a plurality of solar cell cells 3 are arranged in a matrix having a gap region on the same plane. The plurality of solar cells 3 are electrically connected in series by connecting electrodes provided on the front and back surfaces of adjacent solar cells 3.

Here, in the external dimensions of the solar cell strings 3a, the dimension in the first direction, that is, the dimension in the X direction is X3, and the dimension in the second direction, that is, the dimension in the Y direction is Y3. The external dimensions of the solar cell strings 3a in this case are represented by (X3, Y3). Here, X3 is shorter than X2 and Y3 is shorter than Y2. That is, the external dimensions (X3, Y3) of the solar cell strings 3a are smaller than the external dimensions (X2, Y2) of the light receiving surface side sealing layer 2. Therefore, the outer shape of the solar cell strings 3a is smaller than the outer shape of the light receiving surface side sealing layer 2.

As the solar cell 3, for example, a known solar cell such as a crystalline solar cell can be used. Examples of the crystalline solar cell include, but are not limited to, a single crystal silicon solar cell and a polycrystalline silicon solar cell.

The back surface side sealing layer 4 is a region on the back surface side covering member 5 side of the back surface of the solar cell 3 and a region on the back surface side covering member 5 side outside the outer periphery of the solar cell strings 3a in the solar cell panel 10. , The solar cell strings 3a are arranged in the region on the back surface side covering member 5 side of the gap region between the solar cells 3 and the region outside the outer periphery of the light receiving surface side sealing layer 2. The back surface side sealing layer 4 covers the solar cell cell strings 3a from the back surface side and the outer peripheral side of the solar cell cell strings 3a, and seals the solar cell cell strings 3a together with the light receiving surface side sealing layer 2. ..

The back surface side sealing layer 4 covers a region on the back surface of the light receiving surface side sealing layer 2 outside the outer circumference of the solar cell strings 3a from the back surface side. Further, the back surface side sealing layer 4 covers the outer periphery of the light receiving surface side sealing layer 2. That is, the back surface side sealing layer 4 is fixed to the outer peripheral edge portion on the back surface of the light receiving surface side sealing layer 2 and the outer periphery of the light receiving surface side sealing layer 2.

Further, the back surface side sealing layer 4 is the entire circumference of the region outside the light receiving surface side sealing layer 2 on the back surface of the light transmitting substrate 1, that is, the light receiving surface side sealing layer 2 on the back surface of the light transmitting substrate 1. It is in contact with the entire circumference of the outer peripheral edge portion 1a, which is a region on the outer peripheral side that is not covered by. In the in-plane direction of the light transmissive substrate 1, the back surface side sealing layer 4 preferably has a width of 1 mm or more and is in contact with the entire circumference of the outer peripheral edge portion 1a of the back surface of the light transmissive substrate 1.

The back surface side sealing layer 4 is fixed to the back surface of the solar cell strings 3a and the light transmissive substrate 1 by the adhesive force of the back surface side sealing layer 4, and the light receiving surface side sealing layer 2 and the back surface side sealing layer 4 are fixed to each other. It is fixed to the light receiving surface side sealing layer 2 by the adhesive force of 4.

The backside sealing layer 4 has a relatively small decrease in insulating property in an outdoor environment due to accelerated decomposition due to receiving moisture, heat, and light energy, as compared with a polyolefin resin, such as EVA. A polymer resin having insulating properties is used.

Here, in the external dimensions of the back surface side sealing layer 4, the dimension in the first direction, that is, the dimension in the X direction is X4, and the dimension in the second direction, that is, the dimension in the Y direction is Y4. The external dimensions of the back surface side sealing layer 4 in this case are represented by (X4, Y4). Here, X4 has the same dimensions as X1. Further, Y4 has the same dimensions as Y1.

The back surface side covering member 5 is fixed to the outer surface of the back surface side sealing layer 4 located on the back surface side of the solar cell panel 10 by the adhesive force of the back surface side sealing layer 4. The back surface side of the solar cell panel 10 is the installation surface side of the solar cell module 50. The back surface side covering member 5 protects the solar cell strings 3a sealed in the back surface side sealing layer 4.

The back surface side covering member 5 is made of a resin having insulating properties and weather resistance. As the resin used for the back surface side covering member 5, for example, a fluorine-based resin such as polyethylene terephthalate (PET) and polyvinyl fluoride (PVF), and a polymer resin such as olefin and urethane are preferable. Further, the back surface side coating member 5 may be a single layer of any resin of PET, fluororesin, olefin and urethane, and is selected from the group consisting of PET, fluororesin, olefin and urethane. It may be a laminated body in which a plurality of layers made of at least one kind of resin are laminated.

The back surface side covering member 5 is preferably a laminate of PET sheets made of PET having a relatively high insulating property and weather resistance among the above resins. The laminate of PET sheets is composed of a reflective PET sheet, a thick-film PET sheet, and a weather-resistant PET sheet. The reflective PET sheet is a PET sheet for reflecting sunlight L that cannot be directly incident on the solar cell 3 because it is incident between the solar cells 3 in the solar cell strings 3a and causing it to be incident on the solar cell 3. The thick-film PET sheet is a PET sheet having a thickness for ensuring the thickness of the back surface side covering member 5 in order to maintain the insulation distance between the solar cell 3 and the outside of the solar cell panel 10. The weather-resistant PET sheet is a PET sheet having light resistance that does not easily deteriorate with respect to moisture, light and heat received from the atmosphere.

Here, in the external dimensions of the back surface side covering member 5, the dimension in the first direction, that is, the dimension in the X direction is X5, and the dimension in the second direction, that is, the dimension in the Y direction is Y5. The external dimensions of the back surface side covering member 5 in this case are represented by (X5, Y5). Here, X5 has the same dimensions as X1. Further, Y5 has the same dimensions as Y1.

As described above, the size of the external dimensions of each component constituting the solar cell panel 10 is "X1 = X4 = X5> X2> X3" for the dimensions in the first direction, and the second The dimension in the direction is "Y1 = Y4 = Y5> Y2> Y3". Therefore, the size of the outer shape of each component constituting the solar cell panel 10 is determined by "light transmissive substrate 1 = back surface side sealing layer 4 = back surface side covering member 5> light receiving surface side sealing layer 2> sun. Battery cell strings 3a ".

The holding frame 20 surrounds the outer edge of the solar cell panel 10 over the entire circumference of the outer circumference of the solar cell panel 10 and supports the solar cell panel 10 via the outer edge of the solar cell panel 10. The holding frame 20 is a metal frame made of a metal such as aluminum, and an extruded product is used. As shown in FIG. 4, the holding frame 20 includes a holding groove portion 20a in which the outer edge portion of the solar cell panel 10 is housed.

In the solar cell panel 10 configured as described above, the back surface sealing layer 4 covers the solar cell strings 3a from the back surface side of the solar cell strings 3a and the outer peripheral side of the solar cell strings 3a, and receives light. The surface side sealing layer 2 is covered from the back surface side of the light receiving surface side sealing layer 2 and the outer peripheral side of the light receiving surface side sealing layer 2. The back surface side covering member 5 covers the light receiving surface side sealing layer 2 from the back surface side of the light receiving surface side sealing layer 2 via the back surface side sealing layer 4. The back surface side covering member 5 has a relatively small decrease in insulating property due to the outdoor environment as compared with the light receiving surface side sealing layer 2. Further, the light transmissive substrate 1 covers the light receiving surface side sealing layer 2 from the light receiving surface side. The light transmissive substrate 1 has a relatively small decrease in insulating property due to the outdoor environment as compared with the light receiving surface side sealing layer 2.

That is, in the solar cell panel 10, the light receiving surface side sealing layer 2 has a light transmissive substrate 1 and a back surface side sealing in which the reduction in insulation deterioration due to the outdoor environment is relatively small as compared with the light receiving surface side sealing layer 2. It is surrounded by the layer 4 and the back surface side covering member 5. As a result, the solar cell panel 10 is made of an olefin resin, and the influence of insulation deterioration due to the outdoor environment is relatively large on the light receiving surface side as compared with the light transmitting substrate 1, the back surface side sealing layer 4, and the back surface side covering member 5. The influence of the outdoor environment on the sealing layer 2 can be suppressed, and the decrease in insulation deterioration due to the outdoor environment can be suppressed.

In order to obtain the above-mentioned effects, in the solar cell panel 10, the outer shape of the light receiving surface side sealing layer 2 needs to be smaller than the outer shape of the light transmissive substrate 1. Further, the outer shape of the light receiving surface side sealing layer 2 needs to be larger than the outer shape of the solar cell 3 and the conductive portion connected to the solar cell 3, that is, larger than the outer shape of the solar cell strings 3a.

The polyolefin-based resin such as polyethylene used for the light-receiving surface side sealing layer 2 generates a relatively small amount of acid as the solar cell panel 10 is used over time as compared with EVA, and the solar cell 3 and the sun Deterioration of the conductive portion connected to the battery cell 3 is delayed. That is, the polyolefin-based resin such as polyethylene used for the light-receiving surface side sealing layer 2 does not have a functional group such as a carboxyl group that can be an acid, and does not generate an acid such as acetic acid even when hydrolyzed. Therefore, by using a polyolefin resin for the light receiving surface side sealing layer 2 in contact with the solar cell 3, it is used for the electrode of the solar cell 3 due to the aged use of the light receiving surface side sealing layer 2. Since the metal material such as silver (Ag) is less likely to be oxidized, the moisture resistance deterioration of the solar cell 3 due to the light receiving surface side sealing layer 2 is less likely to occur.

When a nitride film such as silicon nitride (SiN) is provided on the light receiving surface side of the solar cell 3 as an antireflection film or the like, a polyolefin resin is provided on the light receiving surface side sealing layer 2 in contact with the solar cell 3. By using the above, the deterioration of the nitride film due to the aged use of the light receiving surface side sealing layer 2 is unlikely to occur, so that the moisture resistance deterioration of the solar cell 3 due to the light receiving surface side sealing layer 2 is unlikely to occur.

On the other hand, since EVA resin has a functional group such as a carboxyl group that can be an acid, it generates an acid such as acetic acid when it is hydrolyzed by long-term use. Therefore, when EVA is used for the light receiving surface side sealing layer 2 in contact with the solar cell 3, the light receiving surface side sealing layer 2 becomes the light receiving surface side sealing layer 2 due to the generation of acid due to the aged use of the light receiving surface side sealing layer 2. Oxidation of a metal material such as Ag used for the electrodes of the solar cell 3 in contact occurs, and the moisture resistance deterioration of the solar cell 3 caused by the light receiving surface side sealing layer 2 occurs.

Further, when a nitride film is provided as an antireflection film or the like on the light receiving surface side of the solar cell 3, and EVA is used for the light receiving surface side sealing layer 2 in contact with the solar cell 3, the light receiving surface side sealing layer is used. Due to the generation of acid due to the aged use of 2, the nitride film in contact with the light receiving surface side sealing layer 2 is deteriorated, and the moisture resistance of the solar cell 3 is deteriorated due to the light receiving surface side sealing layer 2.

Therefore, in the solar cell panel 10, by using a polyolefin resin for the light receiving surface side sealing layer 2, the solar cell 3 and the solar cell 3 are compared with the case where EVA is used for the light receiving surface side sealing layer 2. Deterioration of the connected conductive portion can be slowed down. As a result, the solar cell panel 10 can suppress the deterioration of the output of the solar cell 3 and the solar cell strings 3a over time, and the effect of holding the output of the solar cell panel 10 can be obtained.

However, there is a concern that polyolefin-based resins such as polyethylene may lose their insulating properties in the outdoor environment due to the accelerated decomposition due to the energy of moisture, heat and light. Therefore, in the solar panel 10, the deterioration of the insulating property in the outdoor environment due to the acceleration of decomposition by receiving the energy of moisture, heat and light is relatively small as compared with the polyolefin resin, EVA and the like. The polymer resin having the insulating property of is used for the back surface side sealing layer 4. Then, in the solar cell panel 10, the back surface side sealing layer 4 covers the light receiving surface side sealing layer 2 from the back surface side and the outer peripheral side of the light receiving surface side sealing layer 2. As a result, the solar cell panel 10 is made of an olefin resin, and the influence of the insulation deterioration due to the outdoor environment is relatively larger than that of EVA. The influence of the outdoor environment on the light receiving surface side sealing layer 2 is suppressed, and the light is received by the outdoor environment. It is possible to suppress a decrease in the insulating property of the surface-side sealing layer 2, and it is possible to suppress a decrease in the insulating property of the sealing layer 6.

Further, in the solar cell panel 10, a glass substrate is used, in which the deterioration of the insulating property in the outdoor environment due to the acceleration of decomposition by receiving the energy of moisture, heat and light is relatively small as compared with the polyolefin resin. Used for the light transmissive substrate 1. The light transmissive substrate 1 covers the light receiving surface side sealing layer 2 from the light receiving surface side of the light receiving surface side sealing layer 2. As a result, the solar cell panel 10 is made of an olefin resin, and the influence of the insulation deterioration due to the outdoor environment is relatively larger than that of EVA. The influence of the outdoor environment on the light receiving surface side sealing layer 2 is suppressed, and the light is received by the outdoor environment. It is possible to suppress a decrease in the insulating property of the surface-side sealing layer 2, and it is possible to suppress a decrease in the insulating property of the sealing layer 6.

Therefore, in the solar cell panel 10, by using a polyolefin resin for the light receiving surface side sealing layer 2, the light receiving surface side in the outdoor environment is suppressed while suppressing the aged output deterioration of the solar cell 3 and the solar cell strings 3a. It is possible to suppress a decrease in the insulating property of the sealing layer 2, and the safety and long-term reliability are improved. In order to surely obtain such an effect, in the solar cell panel 10, the back surface side sealing layer 4 covers the light receiving surface side sealing layer 2 from the back surface side covering member 5 side and the surface of the light transmissive substrate 1. In the inward direction, it is in contact with the outer peripheral edge portion 1a of the back surface of the light transmissive substrate 1 with a width of 1 mm or more over the entire circumference of the outer periphery of the light transmissive substrate 1.

In addition, the polyolefin-based resin has fine pores inside the resin due to hydrolysis. When a polyolefin resin is used for the light receiving surface side sealing layer 2, when fine pores are generated inside the polyolefin resin due to hydrolysis, the light receiving surface side sealing layer 2 is outside the light receiving surface side sealing layer 2. The amount of water absorbed increases, and the insulating property of the light receiving surface side sealing layer 2 tends to decrease. Further, the adhesiveness between the light receiving surface side sealing layer 2 and the light transmissive substrate 1 is lowered. Further, if the light receiving surface side sealing layer 2 comes into contact with the back surface side covering member 5, the adhesiveness between the light receiving surface side sealing layer 2 and the back surface side covering member 5 is lowered.

In the solar cell panel 10, the back surface side sealing layer 4 made of a resin such as EVA and PET, which has a relatively high deterioration resistance to hydrolysis as compared with the polyolefin resin, is the back surface side of the light receiving surface side sealing layer 2. And the light receiving surface side sealing layer 2 is covered from the outer peripheral side to shield the light receiving surface side sealing layer 2 from the outside air. As a result, in the solar cell panel 10, the light receiving surface side sealing layer 2 made of the polyolefin resin is prevented from being hydrolyzed by absorbing the moisture of the outside air, and the light receiving surface side sealing caused by the hydrolysis is prevented. It is possible to prevent a decrease in the insulating property and a decrease in the adhesiveness of the layer 2.

Therefore, in the solar cell panel 10 having the above configuration, a polyolefin resin such as polyethylene, which generates a relatively small amount of acid with aging, is used for the light receiving surface side sealing layer 2. ing. Further, in the solar cell panel 10, a resin such as EVA, which has relatively high deterioration resistance and insulating property against hydrolysis as compared with the polyolefin-based resin, is used for the back surface side sealing layer 4, and the back surface side sealing layer 4 is used. The light receiving surface side sealing layer 2 is shielded from the outside air. As a result, the solar cell panel 10 is realized in which the output deterioration over time and the deterioration of the insulating property of the sealing layer 6 are suppressed, and the long-term reliability and safety are improved.

Next, an example of a manufacturing method of the solar cell module 50 configured as described above will be described. FIG. 5 is a flowchart showing a procedure of a method for manufacturing the solar cell module 50 according to the first embodiment of the present invention. FIG. 6 is an exploded perspective view showing the configuration of the solar cell panel 10 according to the first embodiment of the present invention before laminating. FIG. 7 is a cross-sectional view showing the configuration of the laminated body 10a before laminating in the manufacturing process of the solar cell panel 10 according to the first embodiment of the present invention. FIG. 6 shows a case where the solar cell strings 3a in which 24 solar cells 3 are electrically connected in series are used.

First, in step S10, the first step, the laminating step, is performed. In the laminating step, the light receiving surface side sealing layer sheet 2a, the solar cell strings 3a, the back surface side sealing layer sheet 4a, and the back surface side are placed on the light transmissive substrate 1 in the positional relationship as shown in FIG. The covering member sheet 5a and the covering member sheet 5a are laminated in this order to form a laminated body 10a as shown in FIG. 7.

The light receiving surface side sealing layer sheet 2a is a resin sheet made of a polyolefin resin and becomes the light receiving surface side sealing layer 2 after the laminating step. The backside sealing layer sheet 4a has a relatively small decrease in insulating property in an outdoor environment due to accelerated decomposition due to receiving moisture, heat, and light energy, as compared with a polyolefin resin, such as EVA. It is a resin sheet made of an insulating resin and which becomes the back surface side sealing layer 4 after the laminating step. The back surface side covering member sheet 5a is a resin sheet that becomes the back surface side covering member 5 after the laminating step. The solar cell strings 3a are formed by connecting a plurality of solar cells 3 manufactured by a known method to each other using lead wires.

Here, the external dimensions of each component constituting the laminated body 10a will be described.

The external dimensions of the light transmissive substrate 1 are represented by (X1, Y1) as described above.

In the external dimensions of the light receiving surface side sealing layer sheet 2a, the dimension in the first direction, that is, the dimension in the X direction is X2s, and the dimension in the second direction, that is, the dimension in the Y direction is Y2s. The external dimensions of the light receiving surface side sealing layer sheet 2a in this case are represented by (X2s, Y2s). Here, X2s is shorter than X1 and Y2s is shorter than Y1. That is, the external dimensions (X2s, Y2s) of the light receiving surface side sealing layer sheet 2a are smaller than the external dimensions (X1, Y1) of the light transmissive substrate 1.

The external dimensions of the solar cell strings 3a are represented as (X3, Y3) as described above. Here, X3 is shorter than X2s and Y3 is shorter than Y2s. That is, the external dimensions (X3, Y3) of the solar cell strings 3a are smaller than the external dimensions (X2s, Y2s) of the light receiving surface side sealing layer sheet 2a.

In the external dimensions of the back surface side sealing layer sheet 4a, the dimension in the first direction, that is, the dimension in the X direction is X4s, and the dimension in the second direction, that is, the dimension in the Y direction is Y4s. The external dimensions of the back surface side sealing layer sheet 4a in this case are represented as (X4s, Y4s). Here, X4s is longer than X1. Also, Y4s is longer than Y1. That is, the external dimensions (X4s, Y4s) of the back surface side sealing layer sheet 4a are larger than the external dimensions (X1, Y1) of the light transmissive substrate 1.

In the external dimensions of the back surface side covering member sheet 5a, the dimension in the first direction, that is, the dimension in the X direction is X5s, and the dimension in the second direction, that is, the dimension in the Y direction is Y5s. The external dimensions of the back surface side covering member sheet 5a in this case are represented as (X5s, Y5s). Here, X5s is longer than X4. Also, Y5s is longer than Y4. That is, the external dimensions (X5s, Y5s) of the back surface side covering member sheet 5a are larger than the external dimensions (X4s, Y4s) of the back surface side sealing layer sheet 4a.

As described above, the size of the external dimensions of each component constituting the laminated body 10a is "X5s> X4s> X1> X2s> X3" for the dimensions in the first direction, and the second direction. The dimensions of are "Y5s> Y4s> Y1> Y2s> Y3". Therefore, the size of the outer shape of each component constituting the laminated body 10a is determined by "back surface side covering member sheet 5a> back surface side sealing layer sheet 4a> light transmissive substrate 1> light receiving surface side sealing layer sheet 2a. > Solar cell strings 3a ”.

Next, in step S20, the laminating step, which is the second step, is performed. FIG. 8 is a schematic cross-sectional view showing a solar cell panel manufacturing apparatus 100 used for manufacturing the solar cell panel 10 according to the first embodiment of the present invention. The solar cell panel manufacturing device 100 is a known resin sealing device generally used for manufacturing a solar cell panel, that is, a vacuum heating laminating device.

The solar cell panel manufacturing apparatus 100 includes a main body 101 and a cooling conveyor 103. The main body 101 conveys the first member 101a arranged below, the second member 101b having a function of pressing after melting the sealing material and arranged above the first member 101a, and the laminated body 10a. An annular transport sheet 101c for the purpose is provided. Further, the first member 101a includes a heater 101H for heating the laminated body 10a. Although the case where the laminating step is performed in the atmosphere has been shown, the solar cell panel manufacturing apparatus 100 may be configured to laminate the laminated body 10a in a vacuum.

The cooling conveyor 103 is arranged on the downstream side of the main body 101. The cooling conveyor 103 has a function of cooling the laminated body 10a discharged from the main body 101 after being melted and pressurized by air cooling, and a function of transporting the laminated body 10a. The cooling conveyor 103 is configured by arranging a plurality of rollers in parallel, but may be configured by a known transfer sheet and transfer chain.

In the laminating step, in the solar cell panel manufacturing apparatus 100, the laminated body 10a is placed on the first member 101a in a state of being placed on the transport sheet 101c. Then, the periphery of the laminated body 10a is evacuated, heat treatment is performed on the laminated body 10a using the heater 101H, and the light receiving surface side sealing layer sheet 2a and the back surface side sealing layer sheet 4a are melted. The melt pressurization process, which is a laminate sealing process of pressurizing the laminate 10a by the second member 101b, is performed. The laminate 10a is heated to a temperature of about 70 ° C. or higher and 180 ° C. or lower. Further, the laminated body 10a is pressurized at a pressure of about 0.05 MPa or more and 2.00 MPa or less for a heating time of 1 min or more and 120 min or less. As a result, the solar cell strings 3a are sealed inside the sealing layer 6 formed by integrating the light receiving surface side sealing layer sheet 2a and the back surface side sealing layer sheet 4a.

After the melt pressurization treatment, the laminated body 10a integrated and discharged from the main body 101 is transferred to the cooling conveyor 103 and cooled. As a result, the melted light-receiving surface side sealing layer sheet 2a and the back surface side sealing layer sheet 4a are cured. After the laminating step, the resin protruding from the end face of the light transmissive substrate 1 is cut off, and the external dimensions are adjusted to the same size as the external dimensions of the light transmissive substrate 1 before laminating. Through the above steps, a solar cell panel 10 having a cross section as shown in FIG. 9 can be obtained. FIG. 9 is a schematic cross-sectional view showing a solar cell panel 10 manufactured by the method for manufacturing a solar cell panel according to the first embodiment of the present invention.

By setting the temperature of the laminated body 10a when the laminated body 10a is pressed higher than the melting point of the light receiving surface side sealing layer sheet 2a and the melting point of the back surface side sealing layer sheet 4a, the light receiving surface side sealing layer is formed. To produce a uniform solar cell panel 10 in which there are no air bubbles inside the sheet 2a and the back surface side sealing layer sheet 4a, and there is no peeling of the light receiving surface side sealing layer sheet 2a and the back surface side sealing layer sheet 4a. Is possible.

Next, in step S30, the holding frame attaching step, which is the third step, is performed. In the holding frame attaching step, the holding frame 20 is attached and fixed to the outer edge of the solar cell panel 10 over the entire circumference of the outer circumference of the solar cell panel 10. By going through the above steps, the solar cell module 50 can be obtained.

As described above, in the solar cell panel 10 according to the first embodiment, a polyolefin-based resin in which the amount of acid generated with aging is relatively smaller than that of EVA is applied to the light receiving surface side sealing layer 2. I'm using it. Further, in the solar cell panel 10, a resin such as EVA, which has relatively high deterioration resistance and insulating property against hydrolysis as compared with the polyolefin-based resin, is used for the back surface side sealing layer 4, and the back surface side sealing layer 4 is used. The light receiving surface side sealing layer 2 is shielded from the outside air. As a result, the solar cell panel 10 can suppress deterioration of output over time and deterioration of the insulating property of the sealing layer 6, and can realize the solar cell panel 10 with improved long-term reliability and safety.

Hereinafter, the solar cell panel 10 according to the first embodiment will be described based on a specific embodiment. Samples of the solar cell panels of Example 1, Comparative Example 1 and Comparative Example 2 were prepared and evaluated. FIG. 10 is a diagram showing preparation conditions for samples of Example 1, Comparative Example 1 and Comparative Example 2. In FIG. 10, solar cell strings are referred to as cell strings, and solar cells are referred to as cells.

Example 1.
Following the manufacturing method of the solar cell module 50 described above, the light transmitting substrate 1, the light receiving surface side sealing layer sheet 2a serving as the light receiving surface side sealing layer 2, the solar cell strings 3a, and the back surface side sealing layer 4 The back surface side sealing layer sheet 4a and the back surface side covering member sheet 5a serving as the back surface side covering member 5 were sequentially laminated to form a laminated body.

For the light transmissive substrate 1, a white plate glass having a size of first direction: 600 mm × second direction: 450 mm × thickness: 3.2 mm was used. As the light receiving surface side sealing layer sheet 2a, a polyethylene resin sheet having a size of 1st direction: 590 mm × 2nd direction: 440 mm × thickness: 0.6 mm was used.

As the solar cell strings 3a, the solar cell strings 3a having a size of the first direction: 580 mm or less × the second direction: 430 mm or less were used. In the solar cell strings 3a, two cell sets in which three solar cells 3 are connected in series by wiring are arranged in parallel, and the solar cells 3 are arranged in two rows and three columns to form six suns. The battery cells 3 are connected in series.

For the back surface side sealing layer sheet 4a, an EVA resin sheet having a size of 1st direction: 610 mm × 2nd direction: 460 mm × thickness: 0.4 mm was used. For the back surface side covering member sheet 5a, a PET sheet having a size of 620 mm × second direction: 470 mm × thickness: 0.1 mm in which a PET film was laminated was used.

The back surface side sealing layer sheet 4a and the back surface side covering member sheet 5a are provided with notches so that the output terminals can be taken out from the back surface side of the solar cell panel. In addition, wiring was attached to the solar cell 3 of the solar cell strings 3a so that an image of EL emission (Electro-Luminescence) when the solar cell 3 was energized could be confirmed.

Next, the solar cell panel manufacturing apparatus 100 shown in FIG. 8 was configured so that it could be laminated in a vacuum, and the laminated body was laminated. The laminating process was carried out under the conditions that the laminated body was heated to 160 ° C., evacuated for 5 minutes, the pressing pressure was 50 KPa, and the pressing time was 30 minutes.

After the laminating process, the resin protruding from the end face of the light transmissive substrate 1 is cut off with a cutter knife, and the external dimensions are adjusted to the same external dimensions as the external dimensions of the light transmissive substrate 1 before the laminating process. A solar cell panel having an appearance and a cross-sectional shape similar to that in FIG. 3 was produced. The sample of the solar cell panel produced as described above was used as the sample of Example 1.

The reason why the outer dimensions of the back surface side covering member sheet 5a are larger than the outer dimensions of the back surface side sealing layer sheet 4a is that the back surface side sealing layer sheet 4a serves as the top plate of the solar cell panel manufacturing apparatus 100 during the laminating process. This is because there is a possibility of adhering to the second member 101b and contaminating the solar cell panel manufacturing apparatus 100.

Comparative example 1.
The size of the light receiving surface side sealing layer sheet 2a is the first in place of the polyethylene resin sheet having the size of the first direction: 590 mm × the second direction: 440 mm × the thickness: 0.6 mm used in the first embodiment. A solar cell panel was produced in the same manner as in Example 1 except that a polyethylene resin sheet having a direction of 610 mm × second direction: 460 mm × thickness: 0.6 mm was used. The sample of the solar cell panel produced as described above was used as the sample of Comparative Example 1.

In the sample of Comparative Example 1, the surface of the solar cell 3 is covered with a light receiving surface side sealing layer 2 made of polyethylene and a back surface side sealing layer 4 made of EVA. That is, the sample of Comparative Example 1 includes a region on the surface and outer periphery of the solar cell 3 on the light receiving surface side on the light transmitting substrate 1 side and a region on the light transmitting substrate 1 side in the gap region between the solar cells 3. Is covered with a light receiving surface side sealing layer 2 made of polyethylene. Further, in the sample of Comparative Example 1, the region on the back surface side of the solar cell 3 and the region on the back surface side covering member 5 on the outer circumference and the region on the back surface side covering member 5 side in the gap region between the solar cells 3 are formed. , EVA is covered with a backside sealing layer 4. The light receiving surface side sealing layer 2 is arranged on the entire back surface of the light transmissive substrate 1. Further, the back surface side sealing layer 4 covers the light receiving surface side sealing layer 2 from the back surface side of the light receiving surface side sealing layer 2, but does not cover the outer peripheral side of the light receiving surface side sealing layer 2. .. Therefore, in the sample of Comparative Example 1, the light receiving surface side sealing layer 2 made of polyethylene is exposed on the end surface of the solar cell panel 10.

Comparative example 2.
The size of the light-receiving surface-side sealing layer sheet 2a is first, instead of the polyethylene resin sheet having a size of 590 mm × second direction: 440 mm × thickness: 0.6 mm used in Example 1. A solar cell panel was produced in the same manner as in Example 1 except that an EVA resin sheet having a direction of 610 mm × second direction: 460 mm × thickness: 0.6 mm was used. The sample of the solar cell panel produced as described above was used as the sample of Comparative Example 2.

In the sample of Comparative Example 2, the front surface of the solar cell 3 is covered with a light receiving surface side sealing layer 2 made of EVA and a back surface side sealing layer 4 made of EVA. The light receiving surface side sealing layer 2 is arranged on the entire back surface of the light transmissive substrate 1.

The IV characteristics, EL images, and insulating properties of the samples of Example 1, Comparative Example 1 and Comparative Example 2 prepared as described above were measured. The IV characteristic is the electrical characteristic of the solar cell panel, and is a value such as the output of the solar cell panel when the solar cell panel is irradiated with the light of the irradiance specified in JIS C 8990, and is the current I and the voltage V. It is obtained from the measurement result of. The IV characteristics include maximum output Pm, short-circuit current Isc, and curve factor F. F, series resistance Rs was obtained.

The EL image is an image visualized by capturing an infrared ray (Infrared: IR) generated by forcibly energizing a solar cell with an electric current with an infrared camera. Since the portion of the solar cell having a defect such as cracking is not energized, infrared rays are not generated and the portion remains dark, and a dark portion is generated in the EL image. Therefore, by checking the EL image, it is possible to confirm the malfunction of the solar cell panel due to the malfunction of the solar cell.

Next, the samples of Example 1, Comparative Example 1 and Comparative Example 2 were stored for 4000 hours in a high temperature and high humidity (Damp-Heat: DH, temperature: 85 ° C., humidity: 85%) environment. Then, the IV characteristics, EL images, and insulating properties of the samples of Example 1, Comparative Example 1, and Comparative Example 2 were measured again. The result is shown in FIG. FIG. 11 is a diagram showing the measurement results of the samples of Example 1, Comparative Example 1 and Comparative Example 2. In FIG. 11, the Pm retention rate and the Rs retention rate are expressed as percentages based on the measured values before storage in a high temperature and high humidity environment for 4000 hours.

As is clear from FIG. 11, in Comparative Example 1, since the surface of the solar cell 3 on the light receiving surface side is coated with polyethylene, there is almost no deterioration in moisture resistance at the maximum output Pm. In Comparative Example 1, by using the polyolefin resin for the light receiving surface side sealing layer 2, acid is not generated in the light receiving surface side sealing layer 2 due to aged use. Therefore, in Comparative Example 1, oxidation due to the light receiving surface side sealing layer 2 of the metal material such as silver (Ag) used for the electrode of the solar cell 3 is unlikely to occur, and the light receiving surface side sealing layer 2 is unlikely to occur. It is considered that the fact that the moisture resistance deterioration of the solar cell 3 due to the above is less likely to occur contributes to the suppression of the moisture resistance deterioration of the maximum output Pm. However, in the sample of Comparative Example 1, since the outer peripheral side of the light receiving surface side sealing layer 2 is not covered with the back surface side sealing layer 4 made of EVA, the end face of the solar cell panel 10 is sealed on the light receiving surface side made of polyethylene. Since the layer 2 is exposed, the insulating property of the sealing layer 6 is lowered, and the insulation resistance value is lowered.

Further, since the sample of Comparative Example 2 uses EVA for the light receiving surface side sealing layer 2, the moisture resistance deterioration of the maximum output Pm is large. That is, the EVA used for the light receiving surface side sealing layer 2 has a functional group such as a carboxyl group that can be an acid, and an acid such as acetic acid is generated by hydrolysis with aging. Therefore, it is considered that the sample of Comparative Example 2 has a larger moisture resistance deterioration of the maximum output Pm than that of Example 1 and Comparative Example 1. However, in the sample of Comparative Example 1, since the solar cell panel 10 is entirely covered with EVA, the insulating property of the sealing layer 6 is high.

When the light receiving surface side sealing layer 2 is EVA, Ag or the like formed on the light receiving surface of the solar cell 3 due to the acid generated by the hydrolysis of the light receiving surface side sealing layer 2 with aging. A phenomenon occurs in which the electrodes of the above are oxidized and cannot collect electricity. In the sample of Comparative Example 2, since the light receiving surface side sealing layer 2 is EVA, the electrodes formed on the light receiving surface of the solar cell 3 are oxidized and electricity cannot be collected, EL light emission is not confirmed, and the dark part is dark. The dark part generation phenomenon occurs, and as shown in FIG. 11, the result is that the dark part is generated.

On the other hand, in the samples of Example 1 and Comparative Example 1, since the light-receiving surface side sealing layer 2 is made of polyethylene, the electrode formed on the light-receiving surface of the solar cell 3 has a light-receiving surface as described above over time. It does not deteriorate due to the acid generated from the side sealing layer 2. Therefore, in the samples of Example 1 and Comparative Example 1, since the electrode formed on the light receiving surface of the solar cell 3 is less likely to be oxidized, the dark part generation phenomenon is less likely to occur, and as shown in FIG. 11, it is said that no dark part is generated. The result is.

When the light receiving surface side sealing layer 2 is EVA, Ag or the like formed on the light receiving surface of the solar cell 3 due to the acid generated by the hydrolysis of the light receiving surface side sealing layer 2 with aging. The phenomenon that the electrode of the above is oxidized and the resistance value of the electrode rises occurs. In the sample of Comparative Example 2, since the light receiving surface side sealing layer 2 is EVA, a phenomenon occurs in which the electrode formed on the light receiving surface of the solar cell 3 is oxidized by the acid and the resistance value of the electrode increases. However, as shown in FIG. 11, the result is that the Rs retention rate increases. Therefore, in the sample of Comparative Example 2, the maximum output Pm is lowered, resulting in a decrease in the power generation capacity.

On the other hand, in the sample of Example 1, since polyethylene is used for the light receiving surface side sealing layer 2, the light receiving surface side sealing layer 2 is more than that of Comparative Example 2 in which EVA resin is used for the light receiving surface side sealing layer 2. The generation of acid inside is suppressed, and there is almost no deterioration in moisture resistance at the maximum output Pm. Further, in the sample of Example 1, since the light receiving surface side sealing layer 2 is made of polyethylene, the electrode formed on the light receiving surface of the solar cell 3 is oxidized by the acid, and the resistance value of the electrode increases. Is not generated, and as shown in FIG. 11, the Rs retention rate is well maintained. Therefore, in the sample of Example 1, the maximum output Pm is well maintained and the power generation capacity is well maintained even after being stored at high temperature and high voltage for 4000 hours.

Further, in the sample of Example 1, the back surface side sealing layer 4 made of EVA is an outer peripheral edge portion 1a which is an outer peripheral side region which is not covered by the light receiving surface side sealing layer 2 on the back surface of the light transmissive substrate 1. It was confirmed that there was no deterioration in the insulating property because it was in contact with the entire circumference of the. That is, in the sample of Example 1, it was confirmed that the insulating property was not deteriorated because the light receiving surface side sealing layer 2 made of polyethylene was not exposed on the end surface of the solar cell panel 10.

Based on the above results, the method for manufacturing a solar cell panel according to the first embodiment suppresses aged deterioration of output and deterioration of the insulating property of the sealing layer 6, and improves long-term reliability and safety. It was confirmed that the panel 10 can be produced stably.

The configuration shown in the above-described embodiment shows an example of the content of the present invention, can be combined with another known technique, and is one of the configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

1 Light transmissive substrate, 1a Outer peripheral edge, 2 Light receiving surface side sealing layer, 2a Light receiving surface side sealing layer sheet, 3 Solar cell, 3a Solar cell strings, 4 Back side sealing layer, 4a Back side sealing Stop layer sheet, 5 Back side covering member, 5a Back side covering member sheet, 6 Sealing layer, 10 Solar cell panel, 10a Laminated body, 20 Holding frame, 20a Holding groove, 50 Solar cell module, 100 Solar cell panel manufacturing equipment , 101 main body, 101H heater, 101a first member, 101b second member, 101c transfer sheet, 103 cooling conveyor, L sunlight.

Claims

A solar cell string in which a plurality of solar cells are electrically connected is a back surface facing a light receiving surface side protective member arranged on the light receiving surface side of the solar cell strings and a light receiving surface of the solar cell strings. A solar cell panel sealed in a sealing layer sandwiched between a back surface side covering member arranged on the side.
The sealing layer is
A light-receiving surface-side sealing layer composed of a polyolefin resin and covering the entire surface of the light-receiving surface side of the solar cell strings,
It is composed of an ethylene-vinyl acetate copolymer resin, and the solar cell strings are coated from the back surface side of the solar cell strings, and the light receiving surface side sealing layer is coated on the back surface side of the light receiving surface side sealing layer and the light receiving light. The backside sealing layer that covers from the outer peripheral side of the front side sealing layer,
A solar cell panel characterized by being equipped with.
The outer shape of the solar cell panel in the in-plane direction of the light receiving surface side protective member is rectangular.
When the direction parallel to the pair of opposing sides in the rectangular shape is the first direction and the direction parallel to the other pair of opposite sides in the rectangular shape is the second direction,
The light receiving surface side sealing layer has both the dimensions in the first direction and the dimensions in the second direction smaller than the light receiving surface side protective member, and the dimensions in the first direction and the second direction. Both dimensions in the direction of are larger than the solar cell strings,
The back surface side sealing layer has a larger dimension in both the first direction and the second direction than the light receiving surface side sealing layer.
The solar cell panel according to claim 1.
The back surface side sealing layer is in contact with the entire circumference of the outer peripheral edge portion outside the outer circumference of the solar cell strings on the back surface of the light receiving surface side protective member.
The solar cell panel according to claim 1 or 2.
The back surface sealing layer is at least one selected from the group consisting of a single layer of polyethylene terephthalate, a fluororesin, an olefin and a urethane resin, or a group consisting of polyethylene terephthalate, a fluororesin, an olefin and urethane. Being a laminated body in which a plurality of layers made of resin are laminated,
The solar cell panel according to any one of claims 1 to 3.
The solar cell panel according to any one of claims 1 to 4.
A holding frame that is attached to the entire circumference of the outer circumference of the solar cell panel and holds the solar cell panel,
A solar cell module characterized by being equipped with.
On the light receiving surface side protective member, a light receiving surface side sealing layer sheet composed of a polyolefin resin and serving as a light receiving surface side sealing layer, a solar cell string in which a plurality of solar cells are electrically connected, and a solar cell string. The first step of sequentially laminating the back surface side sealing layer sheet to be the back surface side sealing layer and the back surface side covering member to form a laminated body.
The second step of forming a solar cell panel by integrating the laminated bodies by heating and pressurizing the laminated body, and
Including
In the second step,
The light-receiving surface-side sealing layer sheet covers the entire surface of the solar cell strings on the light-receiving surface side.
The back surface side sealing layer sheet covers the solar cell strings from the back surface side of the solar cell strings facing the light receiving surface, and the light receiving surface side sealing layer is covered with the light receiving surface side sealing layer. Covering from the back surface side and the outer peripheral side of the light receiving surface side sealing layer,
The solar cell strings are sealed inside the sealing layer formed by integrating the light receiving surface side sealing layer sheet and the back surface side sealing layer sheet.
A method for manufacturing a solar cell panel.
In the second step, the back surface side sealing layer sheet comes into contact with the entire circumference of the outer peripheral edge portion outside the outer circumference of the solar cell strings on the back surface of the light receiving surface side protective member.
The method for manufacturing a solar cell panel according to claim 6.
In the second step, the laminate is pressurized in a state of being heated to a temperature equal to or higher than the melting point of the light receiving surface side sealing layer sheet and the back surface side sealing layer sheet.
The method for manufacturing a solar cell panel according to claim 6 or 7.
On the light receiving surface side protective member, a light receiving surface side sealing layer sheet composed of a polyolefin resin and serving as a light receiving surface side sealing layer, a solar cell string in which a plurality of solar cells are electrically connected, and a solar cell string. The first step of sequentially laminating the back surface side sealing layer sheet to be the back surface side sealing layer and the back surface side covering member to form a laminated body.
The second step of forming a solar cell panel by integrating the laminated bodies by heating and pressurizing the laminated body, and
The third step of attaching the holding frame for holding the solar cell panel to the entire circumference of the outer circumference of the solar cell panel, and
Including
In the second step,
The light-receiving surface side sealing layer sheet covers the light-receiving surface side of the solar cell strings.
The back surface side sealing layer sheet covers the solar cell strings from the back surface side of the solar cell strings facing the light receiving surface, and the light receiving surface side sealing layer is covered with the light receiving surface side sealing layer. Covering from the back surface side and the outer peripheral side of the light receiving surface side sealing layer,
The solar cell strings are sealed inside the sealing layer formed by integrating the light receiving surface side sealing layer sheet and the back surface side sealing layer sheet.
A method for manufacturing a solar cell module.