WO2013125877A1 - Backsheet for solar cell module and solar cell module comprising same - Google Patents

Description

Back sheet for solar cell module and solar cell module comprising same

The present invention relates to a solar cell module back sheet and a solar cell module including the same. More particularly, the present invention relates to a solar cell module back sheet having the excellent heat dissipation, which can improve the amount of power generation of a solar cell and to be distributed at a low price, and has excellent adhesive strength.

Recently, solar cells have been developed as next-generation environmentally friendly energy sources and are rapidly being used for residential, industrial, and the like.

The solar cell is composed of a plurality of solar cells (module) is modular. At this time, the plurality of solar cells are packed and fixed to the encapsulation layer, and a back sheet as a sealing member is bonded to the lower surface of the encapsulation layer to be modularized. This will be described with reference to FIG. 1. 1 is a cross-sectional view of a conventional solar cell module according to the related art, in which a back sheet according to the prior art is shown.

Referring to FIG. 1, a solar cell module generally includes transparent tempered glass 3 to which light is incident, an upper encapsulation layer 2a, a plurality of solar cells C, a lower encapsulation layer 2b, and a back sheet 1. ) Has a stacked structure. The plurality of solar cells C are packed and fixed in the encapsulation layers 2a and 2b. That is, as shown in FIG. 1, the plurality of solar cells C are packed and fixed between the upper encapsulation layer 2a and the lower encapsulation layer 2b. In this case, the encapsulation layers 2a and 2b mainly use ethylene vinyl acetate (EVA), which is advantageous for packing (fixing) the solar cell (C). The back sheet 1 is adhered to a lower surface of the solar cell module, that is, the lower surface of the lower encapsulation layer 2b to protect the solar cell C.

The solar cell module is required to have a long life without output degradation over a long time. For this long life, the back sheet 1 should be able to block moisture or oxygen that adversely affects the solar cell C, and to prevent degradation due to ultraviolet rays. In recent years, the cost reduction of the back sheet 1 is strongly demanded. Accordingly, the back sheet 1 should be made of a material having heat resistance and durability (weather resistance) that can withstand high temperature, humidity, ultraviolet rays, etc., to prolong the life of the solar cell module. do.

In general, the solar cell module back sheet 1 has a structure in which a heat resistant polyethylene terephthalate (PET) film and a weather resistant fluorine film are laminated as a base substrate. Specifically, as shown in FIG. 1, the back sheet 1 includes a PET film 1a as a base substrate and a fluorine-based film 1b adhered to the PET film 1a through an adhesive. Republic of Korea Patent No. 10-1022820 and Republic of Korea Patent Publication No. 10-2011-0020227 discloses a technology related to this.

The PET film 1a is useful as a base substrate of the back sheet 1 due to its excellent heat resistance and excellent durability such as mechanical strength. In addition, as the fluorine-based film 1b, films such as polyvinylidene fluoride (PVDF) or polyvinyl fluoride (PVF) are mainly used. The fluorine-based film 1b has an advantage of excellent durability (weather resistance) and the like.

However, the conventional back sheet 1 has a problem in that the price of the constituent material is high and the price is not competitive. Specifically, in constituting the conventional back sheet 1, for durability (weather resistance), a fluorine-based film 1b such as PVDF or PVF molded into a film as described above is applied to the PET film 1a. In this case, the fluorine-based film 1b such as PVDF or PVF has a problem in that the price of the film itself is high and the price of the back sheet 1 cannot be reduced.

In addition, the conventional back sheet 1 is poor in interlayer adhesion of each layer constituting the back sheet 1, adhesive strength for modularization, poor durability, etc., and is not good in terms of barrier properties such as moisture barrier properties. There is a problem. Specifically, although the PET film 1a and the fluorine-based film 1b are adhered through an adhesive, there is a problem in that the interlayer adhesion between the two films 1a and 1b is weak. In addition, the back sheet 1 should be firmly adhered to the lower encapsulation layer 2b of the solar cell module, that is, the EVA sheet, to maintain sealing property. However, the back sheet 1 has a weak adhesive strength between the fluorine-based film 1b and the EVA sheet, resulting in poor durability. There is this. In addition, the fluorine-based film 1b is advantageous in durability and the like, but also has problems of poor barrier properties such as moisture barrier property due to high moisture permeability.

On the other hand, the solar cell generates heat during driving. At this time, the generated heat should be dissipated (discharged) to the outside as much as possible, which is advantageous for the light conversion efficiency (efficiency for converting light into electricity) of the solar cell, that is, the amount of power generation. However, the conventional back sheet 1 has a problem in that there is no heat dissipation for dissipating heat generated from the solar cell or low, and thus the power generation amount (light conversion efficiency) of the solar cell is not improved.

[Preceding technical literature]

(Patent Document 1) Republic of Korea Patent No. 10-1022820

(Patent Document 2) Republic of Korea Patent Publication No. 10-2011-0020227

Accordingly, an object of the present invention is to provide a solar cell module back sheet having excellent durability and heat dissipation and a solar cell module including the same.

In addition, an object of the present invention is to provide a back sheet for a solar cell module having excellent adhesiveness and barrier properties (such as moisture barrier) and a solar cell module including the same.

The present invention to achieve the above object,

materials;

A surface layer formed on one surface of the substrate; And

It is formed on the other side of the substrate and provides a back sheet for a solar cell module comprising a heat dissipation material and a heat dissipation fluorine coating layer containing a fluorine resin.

In this case, the substrate may include at least one selected from a polyester film layer and a metal layer. Moreover, a base material contains a metal layer, and the said metal layer can use what is two or more layers from which a thermal conductivity differs.

In addition, the surface layer may include at least one selected from a polyethylene-based film layer and a fluorine coating layer. In this case, the polyethylene film layer may include a white inorganic material, and the fluorine coating layer may include an ethylene-containing fluorine resin.

In addition, the present invention provides a solar cell module comprising the back sheet according to the present invention.

According to the present invention, it has excellent durability and heat dissipation, including a heat dissipating fluorine coating layer. Accordingly, the lifespan of the solar cell module can be extended, and the heat generated from the solar cell can be efficiently dissipated (discharged) to improve the power generation amount (light conversion efficiency) of the solar cell. In addition, it can be spread at a lower price than the conventional one, and is excellent in adhesiveness and barrier properties (such as moisture barrier property).

1 is a cross-sectional view of a solar cell module and a back sheet according to the prior art.

2 is a cross-sectional view of a solar cell module back sheet according to a first embodiment of the present invention.

3 is a cross-sectional view of a solar cell module back sheet according to a second embodiment of the present invention.

4 is a cross-sectional view of a solar cell module back sheet according to a third embodiment of the present invention.

5 is a cross-sectional view of a solar cell module back sheet according to a fourth embodiment of the present invention.

6 is a cross-sectional configuration diagram of a solar cell module back sheet according to a fifth embodiment of the present invention.

7 is a cross-sectional view of a solar cell module according to an exemplary embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention. The accompanying drawings show illustrative embodiments depicted in order to facilitate understanding of the present invention. 2 is a cross-sectional view of a solar cell module back sheet according to a first embodiment of the present invention. 3 is a cross-sectional view of a solar cell module back sheet according to a second embodiment of the present invention. 4 is a cross-sectional view of a solar cell module back sheet according to a third embodiment of the present invention. 5 is a cross-sectional configuration diagram of a solar cell module back sheet according to a fourth embodiment of the present invention, and FIG. 6 is a cross-sectional configuration diagram of a solar cell module back sheet according to a fifth embodiment of the present invention.

First, referring to FIG. 2, the solar cell module back sheet (hereinafter, abbreviated as "back sheet") according to the present invention is the base layer 10 and the surface layer 20 formed on one surface of the base 10. ), And a heat dissipating fluorine coating layer 30 formed on the other side of the substrate 10. In this case, the heat dissipating fluorine coating layer 30 may contain a heat dissipation material and a fluorine resin.

The substrate 10 is not limited as long as it has a bearing force. The substrate 10 may further have one or more selected from heat resistance, barrier properties, heat dissipation properties, and the like together with the supporting force. The substrate 10 may be made of one or more materials selected from, for example, a synthetic resin material and a metal material. At this time, when the substrate 10 is made of a synthetic resin material, it may be selected from, for example, polyester, polyolefin, and polyamide. For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT; Polybutyleneterephthalate), polyethylene naphthalate (PEN; Polyethylenenaphthalate), polybutylene naphthalate (PBN; Polybutylenenaphthalate), polyethylene (PE; Ppolyetylene) and poly It may be composed of one or more selected from propylene (PP; Polypropylene) and the like.

According to one embodiment of the invention, the substrate 10 may include one or more selected from the polyester film layer 12 and the metal layer 14. Specifically, the substrate 10 may be composed of a polyester film layer 12 as illustrated in FIG. 2, or may be composed of a metal layer 14 as illustrated in FIGS. 3 and 4. In addition, the substrate 10 may include a polyester film layer 12 and a metal layer 14 formed on the polyester film layer 12 as illustrated in FIG. 5. In this case, the polyester film layer 12 is excellent in heat resistance and barrier properties, and the metal layer 14 is excellent in heat resistance and barrier properties as well as heat dissipation.

2 illustrates a first embodiment of the present invention, which illustrates a state in which the polyester film layer 12 is applied as the substrate 10.

The polyester film layer 12 is not limited as long as it contains a polyester-based resin, for example, by molding a composition containing a polyester-based resin polymerized with a compound having a carboxyl group and a compound having a hydroxyl group in the form of a film Can be used.

In addition, the polyester film layer 12 is a polyester resin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT) and polybutylene naphthalate ( PBN) and the like. More specifically, the polyester film layer 12 may include one or more resins selected from polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and the like having ethylene in the molecule among those listed above. Further, the polyester film layer 12 may be composed of a polyethylene terephthalate film (PET film) or polyethylene naphthalate film (PEN film).

In addition, the polyester film layer 12 is not particularly limited, but may have a thickness of, for example, 50 μm (micrometer) to 1,000 μm. In this case, when the thickness of the polyester film layer 12 is less than 50 μm, barrier properties, heat resistance, mechanical strength (tensile strength, etc.) and dimensional stability may not be good, and when it exceeds 1,000 μm, flexibility or It may not be desirable in terms of cost. In consideration of this point, the polyester film layer 12 may have a thickness of 80 ~ 500㎛, more specifically may have a thickness of 100 ~ 300㎛.

3 illustrates a second embodiment of the present invention, which illustrates the application of the metal layer 14 as the substrate 10.

The metal layer 14 is not limited as long as it includes a thermally conductive metal. The metal layer 14 may be formed of, for example, a metal deposition layer or a metal thin film. The metal layer 14 may be a single layer or a multilayer of two or more layers. In this case, when the metal layer 14 is a metal deposition layer, for example, the metal layer 14 may be formed by being deposited on the surface layer 20 or by being deposited on the polyester film layer 12 as described above.

In the present invention, the metal constituting the metal layer 14 is not limited as long as it is thermally conductive, for example, aluminum (Al), gold (Au), silver (Ag), copper (Cu), nickel (Ni), tin ( Sn), zinc (Zn), tungsten (W) and iron (Fe) may be selected from the group consisting of. Metals in the present invention include those composed of one single metal, a mixture of two or more, or two or more alloys (eg, stainless steel, etc.) selected from the metals listed above. In this case, the metal may be selected from an aluminum (Al) thin film or an aluminum (Al) alloy thin film which is excellent in thermal conductivity and advantageous in weight and price.

The thickness of the metal layer 14 is not limited. The metal layer 14 may have a thickness of 0.01 μm to 1,000 μm. In this case, when the thickness of the metal layer 14 is less than 0.01 μm, heat dissipation and bearing capacity may be insignificant, and when the thickness of the metal layer 14 is more than 1,000 μm, the flexibility of the back sheet 100 may be inferior and may be undesirable in terms of price. In consideration of this point, the metal layer 14 may have a thickness of, for example, 0.1 μm to 500 μm, and more specifically, may have a thickness of 5 μm to 300 μm.

According to another embodiment of the present invention, the metal layer 14 may be a metal corrosion treatment on the surface. That is, the metal layer 14 may include a corrosion protection layer 14b as shown in FIG. 3. Specifically, the metal layer 14 may include a metal base layer 14a and a corrosion preventing layer 14b formed on the surface of the metal base layer 14a. In this case, the metal substrate 14a may be a metal deposition layer or a metal thin film.

The anti-corrosion layer 14b may be formed on one side or both sides of the metal substrate 14a, which is not limited as long as it is for preventing corrosion of the metal, that is, for preventing corrosion of the metal substrate 14a. . The corrosion protection layer 14b may be formed by a method used in the general metal field for preventing corrosion of a metal, for example, plating or coating of a corrosion inhibitor. The corrosion preventing layer 14b may be formed by coating one or more selected from corrosion inhibitors such as, for example, phosphoric acid (phosphate) and chromium (chromic acid). As another example, the anti-corrosion layer 14b is an organic material, for example, a silane compound that forms a siloxane bond (Si-O-Si) with a metal, or a thiol group (-SH) that forms a metal-sulfur (S) covalent bond. ) Alkanethiol-based compound and the like may be formed by coating a corrosion inhibitor.

In addition, the corrosion protection layer 14b is not particularly limited, but may have a thickness of, for example, 0.001 μm to 30 μm. At this time, if the thickness of the anti-corrosion layer 14b is less than 0.001 μm, the anti-corrosion effect may be insignificant. If the thickness of the anti-corrosion layer 14b is over 30 μm, it may not be desirable in terms of price. In consideration of this point, the corrosion preventing layer 14b may have a thickness of, for example, 0.01 to 20 μm, and more specifically, a thickness of 0.5 to 10 μm.

In addition, according to one embodiment of the present invention, the metal layer 14 may be composed of two or more layers having different thermal conductivity. Specifically, the metal layer 14 may have a multilayer structure of two or more layers, and each layer may be configured to have different thermal conductivity. In addition, the metal layer 14 may be formed of two or more layers, and may be made of metal having a different material from the adjacent layer. This will be described with reference to FIG. 4.

Figure 4 shows a third embodiment of the present invention, which illustrates a metal layer 14 is applied as a base material 10, but the metal layer 14 is formed in a multi-layer structure.

Referring to FIG. 4, the metal layer 14 may be formed of at least two layers, and the metal constituting each layer may be formed of a metal different from an adjacent layer. That is, the metal layer 14 may be laminated or laminated with two or more metal thin films to have a multilayer structure of two or more layers, but may be formed of metal thin films of different materials from adjacent layers.

At this time, the metal layer 14 of the multilayer structure is not particularly limited, but may have a multilayer structure of 2 to 10 layers, more specifically, 2 to 5 layers. In this case, at least one layer of the multilayer may include an aluminum (Al) thin film, which is advantageous in price, weight, strength, and thermal conductivity. In addition, at least one layer of the multilayer may further include a copper (Cu) thin film that is advantageous in thermal conductivity.

In FIG. 4, a metal layer 14 composed of two layers includes a first metal layer 14-1 and a second metal layer 14-2 laminated and laminated under the first metal layer 14-1. 14) is illustrated. At this time, the metals constituting the first metal layer 14-1 and the second metal layer 14-2 are different from each other. That is, the kind of metal which comprises the metal thin film of each layer differs. For example, the first metal layer 14-1 is composed of an aluminum (Al) thin film, the second metal layer 14-2 is composed of a copper (Cu) thin film, and the metal layer 14 is formed of Al // Cu. It can be a two-layer structure. Each of these metal layers 14-1 and 14-2 may be corrosion-protected as described above. That is, each of the metal layers 14-1 and 14-2 may have a corrosion preventing layer 14b formed on at least one surface thereof.

For another example, the metal layer 14 may include a first metal layer 14-1, a second metal layer 14-2 laminated and laminated under the first metal layer 14-1, and the second metal layer ( 14-2) may have a three-layer structure consisting of a third metal layer (not shown) laminated and laminated. At this time, the metals constituting the first metal layer 14-1, the second metal layer 14-2, and the third metal layer are formed of different metals between adjacent layers. For example, the first metal layer 14-1 is composed of an aluminum (Al) thin film, the second metal layer 14-2 is composed of a copper (Cu) thin film, and the third metal layer is formed of an aluminum (Al) thin film. The metal layer 14 may have a three-layer structure of Al // Cu // Al. In this way, different metals are adjacent to each other. As another example of the three-layer structure, the metal layer 14 may be a three-layer structure composed of Cu // Al // Cu. As another example, all three layers may be different metals and may have a three-layer structure composed of Al // Cu // Ni or a three-layer structure composed of an alloy of Cu // Al // Cu + Zn. have.

The same applies to the fourth and fifth floors. For example, the four layers may have a lamination structure of Al // Cu // Al // Cu, or Al // Cu // stainless steel // Al. That is, the metal layer 14 is formed by stacking two or more kinds of metal thin films, and different metal thin films are adjacent to each other.

In addition, the layers constituting the metal layer 14 may be laminated by one or more means selected from heat and pressure. That is, in bonding each layer, the metal thin films constituting each layer are alternately laminated so that the same metal thin films are not adjacent to each other, and then heat and / or pressure are applied without using any adhesive material such as an adhesive. It is good to add and bond. Preferably, both heat and pressure are applied to be laminated. For example, it may be pressed and laminated through a pressure roller maintaining a predetermined temperature.

As described above, the metal layer 14 may be formed of two or more layers, and each layer may have an excellent heat dissipation property when the metal layer 14 is formed of a different metal from the adjacent layer. For example, when it consists of two layers of Al and Cu as a heterogeneous metal, it has the outstanding heat dissipation property rather than a single layer of Al or Cu.

The back sheet 100 should quickly absorb heat generated from the solar cell and quickly release it to the outside so that the power generation amount (photo conversion efficiency) of the solar cell is improved. That is, the back sheet 100 should have good thermal conductivity and thermal diffusivity as well as heat dissipation efficiency to the outside. Metals generally have the property of having heat, no matter how excellent the thermal conductivity is. Accordingly, when the metal is first heated, heat is rapidly transferred and spreads evenly, and after a certain threshold, the heat of the metal itself is raised. That is, no matter how excellent the thermal conductivity of the metal, even after a certain time, the efficiency of heat release to the outside falls for the same reason.

Taking Al and Cu as an example, Cu has a higher thermal conductivity than Al. At this time, when only Cu is used as the metal layer 10 for heat dissipation, Cu has a high thermal conductivity and can quickly absorb heat from the solar cell. However, Cu has a great tendency to have heat, so the heat release efficiency (heat transfer effect) to the outside is lower than that of Al. In addition, Al has good heat dissipation efficiency to the outside as opposed to Cu, but has a lower heat absorption capacity from Cu than Cu.

Therefore, as the metal layer 14 for heat dissipation, the thermal conductivity (heat absorption capacity from the solar cell) and the heat release efficiency (heat transfer effect) to the outside are achieved by the laminated composite of two or more different metals, for example, Al and Cu. Complementary to each other has excellent heat dissipation. That is, for example, Cu mainly plays a role of quickly absorbing heat from the solar cell, and Al mainly plays a role of quickly dissipating the transferred heat to the outside, thereby achieving excellent heat dissipation. In addition, in the case of Al, it is not only lightweight but also excellent in mechanical strength such as tensile strength, which is useful as a base material for the back sheet 100. In this case, although Al and Cu have been described as an example, in the present invention, the metal layer 10 includes at least two or more kinds of metals different from each other, more specifically, at least two or more kinds of metal thin films having different thermal conductivity are not adjacent to each other. It is not restrict | limited if it has laminated | stacked laminated alternately so that it may have a multilayer structure of two or more layers.

In addition, in laminating each of the two or more layers, in the case of adhering an adhesive material, such as an adhesive, between the layers, the adhesive material may act as an interlayer heat transfer inhibiting element, thereby reducing heat dissipation. In view of this, as described above, each layer is desirable in heat dissipation when laminated via heat and / or pressure. That is, when the adhesive material does not exist between the layers, and the layers are adhered / laminated in a clad manner using heat and pressure, heat dissipation is maximized due to the excellent heat transfer effect between the layers. Accordingly, the metal layer 14 efficiently emits heat generated in the solar cell C (see FIG. 7) to improve the power generation amount (light conversion efficiency) of the solar cell.

FIG. 5 illustrates a fourth embodiment of the present invention, which illustrates a state in which a polyester film layer 12 and a metal layer 14 are applied as a substrate 10.

Referring to FIG. 5, the substrate 10 may include a polyester film layer 12 and a metal layer 14 formed on the polyester film layer 12 as described above. In this case, the metal layer 14 may be formed of a metal deposition layer formed by depositing on the surface of the polyester film layer 12, or may be formed by bonding a metal thin film through heat fusion or an adhesive, and the like. It may have a structure.

In addition, when the base material 10 includes the polyester film layer 12 and the metal layer 14 as described above, as shown in FIG. 5, the metal layer 14 is directly in contact with the heat dissipating fluorine coating layer 30 in terms of heat dissipation. I can come in contact. Specifically, as shown in FIG. 5, the back sheet 100 may have a structure in which the surface layer 20, the polyester film layer 12, the metal layer 14, and the heat dissipating fluorine paint coating layer 30 are sequentially stacked. Can be. At this time, the heat dissipation may be maximized by the adjacent metal layer 14 and the heat dissipating fluorine coating layer 30.

On the other hand, the surface layer 20 is formed on the substrate 10, which may be bonded to the encapsulation layer 220 (see FIG. 7) of the solar cell module. Specifically, the surface layer 20 constitutes the outermost layer of the back sheet 100 according to the present invention, which may be adhered to the lower encapsulation layer 222 (see FIG. 7) of the solar cell module. The surface layer 20 may have heat resistance, durability, and electrolyte resistance. In addition, the surface layer 20 may have an excellent adhesive strength that can be adhered to the encapsulation layer 220 well.

According to one embodiment of the present invention, the surface layer 20 may include at least one selected from a polyethylene film layer 22 and a fluorine coating layer 24. The surface layer 20 may be specifically composed of a polyethylene film layer 22 or a fluorine coating layer 24. In addition, the surface layer 20 may have a structure including both the polyethylene film layer 22 and the fluorine coating layer 24.

The polyethylene-based film layer 22 may be formed by coating a resin composition including polyethylene-based resin, or by molding a film formed from the resin composition by heat fusion or an adhesive. The adhesive is not particularly limited, and for example, one or more adhesives selected from acrylic, urethane and epoxy resins can be used.

The polyethylene resin constituting the polyethylene film layer 22 is not limited as long as it contains ethylene in the molecule. The polyethylene resin may be selected, for example, from homopolymers or ethylene containing copolymers of ethylene monomers. Examples of the copolymer include ethylene monomers and copolymers such as propylene or butylene monomers. As the polyethylene-based resin, for example, one or more selected from polyethylene (PE), ethylene-propylene copolymer, ethylene-butylene copolymer and the like can be used.

According to the present invention, when the above polyethylene-based film layer 22 is applied as the surface layer 20, it has excellent durability and the like, and promotes excellent price competitiveness compared to the conventional back sheet. Specifically, the polyethylene-based film layer 24 is significantly cheaper than the conventional fluorine-based film (1b, see Fig. 1), such as PVDF and PVF, while having a durable price or the like, the back sheet 100 is inexpensive It can be made available at a price.

In addition, the surface layer 20 is bonded to the encapsulation layer 220 of the solar cell module, wherein the surface layer 20 has excellent adhesion when the polyethylene-based film layer 22 as described above. That is, the polyethylene film layer 22 achieves excellent adhesion between the back sheet 100 and the encapsulation layer 220. More specifically, the encapsulation layer 220 of the solar cell module may be generally composed of an ethylene vinyl acetate (EVA) sheet, wherein the polyethylene film layer 22 is homogeneous constituting the ethylene vinyl acetate (EVA) sheet. Including ethylene as a monomer of the has a good adhesion with the encapsulation layer 220.

In addition, in the present invention, the substrate 10 may include a polyester film layer 12 as described above, wherein the surface layer 20 is excellent with the substrate 10 when the surface layer 20 is composed of a polyethylene-based film layer 22. Has interlayer adhesion. That is, the polyester film layer 12 as the base material 10 is preferably composed of a polyethylene terephthalate film (PET film) or polyethylene naphthalate film (PEN film), wherein the polyethylene-based film layer 22 is polyethylene tere Containing ethylene as the homogeneous monomer constituting the phthalate film (PET film) or polyethylene naphthalate film (PEN film), it has excellent interlayer adhesion with the polyester film layer 12. In addition, the polyethylene film layer 22 may improve barrier properties. That is, the polyethylene-based resin constituting the polyethylene-based film layer 22 is excellent in impermeability of gas or liquid, and can improve durability by improving barrier properties such as moisture barrier property to the back sheet 100.

According to one embodiment of the invention, the polyethylene film layer 22 may include a white inorganic material. Specifically, the polyethylene film layer 22 may be made of polyethylene-based resin as a main material, and further include a white inorganic material.

The white inorganic material is not limited as long as it is a white inorganic particle. The white inorganic material may be at least one selected from titanium dioxide (TiO ₂ ), calcium oxide (CaO), magnesium oxide (MgO), and the like. The white inorganic material may include titanium dioxide (TiO ₂ ). That is, a white inorganic material may be a mixture further comprising at least one selected from titanium dioxide (TiO ₂₎ or a structure, titanium dioxide (TiO _2), calcium (CaO) and magnesium oxide (MgO), such as the oxidation.

As described above, when the polyethylene film layer 22 as the surface layer 20 further includes a white inorganic material, mechanical strength may be improved and light conversion efficiency of the solar cell may be improved. That is, the white inorganic material improves the mechanical strength of the polyethylene film layer 22 to increase the durability of the back sheet 100. In addition, the white inorganic material imparts a reflecting ability to the polyethylene-based film layer 22 to reflect the incident sunlight toward the solar cell C. As a result, the amount of light received (the amount of light received) of the solar cell C is increased to improve the light conversion efficiency (the rate at which light is converted to electricity). In this case, as described above, the white inorganic material may include titanium dioxide (TiO ₂ ), and the titanium dioxide (TiO ₂ ) has an excellent effect of improving the reflectance (light conversion efficiency) of sunlight.

In addition, when the polyethylene-based film layer 22 includes a white inorganic material, it may include 2 to 20 parts by weight of a white inorganic material based on 100 parts by weight of polyethylene-based resin. At this time, when the content of the white inorganic material is less than 2 parts by weight, the improvement effect such as mechanical strength and the reflectance of the sunlight (light conversion efficiency) according to the content of the white inorganic material may be insignificant. And when the content of the white inorganic material exceeds 20 parts by weight, the adhesion may be lowered. That is, when the content of the white inorganic material is too much exceeding 20 parts by weight, the content of the polyethylene-based resin is relatively small, the adhesion between the polyethylene film layer 22 and the encapsulation layer 220, and the polyethylene film layer 22 And the interlayer adhesion between the substrate and the substrate 10 may be lowered. In consideration of mechanical strength, reflectivity and adhesion of sunlight, the white inorganic material may be included in an amount of 5 to 15 parts by weight based on 100 parts by weight of polyethylene-based resin.

In addition, the white inorganic material such as titanium dioxide (TiO ₂ ) may have a particle size of 30 μm or less. The white inorganic material may have a particle size of, for example, 0.05-30 μm. In this case, when the particle size of the white inorganic material is less than 0.05 μm, the solar light reflecting effect may be insignificant, and when the particle size of the white inorganic material exceeds 30 μm, the adhesion of the polyethylene resin may be inhibited. The white inorganic material may more specifically have a particle size of 0.1 to 10 μm.

In addition, the polyethylene film layer 22 may have a thickness of 10 ~ 500㎛. At this time, if the thickness of the polyethylene-based film layer 22 is less than 10 ㎛ is too thin, the improvement effect such as durability, adhesive force, mechanical strength and the reflectance of sunlight can be insignificant. If the thickness is too thick, the thickness and the heat dissipation performance of the back sheet 100 may be impaired, which may be undesirable in terms of price. In consideration of this point, the polyethylene-based film layer 22 may include a white inorganic material, and may have a thickness of about 50 μm to about 300 μm.

In addition, the surface layer 20 may include a fluorine coating layer 24 in terms of cost competitiveness and durability (ultraviolet ray shielding, heat resistance, dimensional stability, etc.).

The fluorine coating layer 24 is formed by coating a fluorine resin composition on the substrate 10. That is, in the present invention, the fluorine coating layer 24 is formed by coating and fixing (curing) the liquid fluorine resin composition without bonding the fluorine-based film 1b (see FIG. 1) on the film through an adhesive as in the related art. . Accordingly, according to the present invention, it is possible to reduce the price of the back sheet 100 and to improve the interlayer adhesion. Specifically, the back sheet 100 may be formed by coating a low-cost liquid fluorine resin composition and forming a durable fluorine coating layer 24 without bonding the fluorine-based film 1b such as PVDF, which has a high price of the film itself as in the related art. ) Can be lowered. In addition, the base material 10 and the fluorine coating layer 24 have favorable interlayer adhesion force by coating and hardening of a fluororesin composition.

In addition, the fluorine coating layer 24 may have a thickness of 5 ~ 30㎛. At this time, when the thickness of the fluorine coating layer 24 is less than 5㎛, effects such as durability due to its coating may be insignificant. When the thickness of the fluorine coating layer 24 exceeds 30 µm, the curing time may be long, and it may be difficult to lower the price. As described above, in the case of coating and forming the fluorine coating layer 24 to a thickness of 5 to 30 µm, for example, the price of the fluorine coating layer 24 can be reduced by two times or more than in the case of using a fluorine-based film 1b such as PVDF. . In consideration of durability and price, the fluorine coating layer 24 may have a thickness of 10 to 20 μm.

The fluorine coating layer 24 is formed by coating a fluorine resin composition as described above, wherein the fluorine resin composition includes at least a fluorine resin, and may further include a solvent as a diluent for coating property of the fluorine resin. . In this case, the solvent is not limited as long as the solvent is diluted with a fluorine resin to have a viscosity such that coating is possible. As the solvent, for example, one or more organic solvents selected from alcohols, glycols, ketones, formamides and the like can be used. For example, the solvent may use one or more selected from methanol, ethanol, isopropanol, methylene glycol, ethylene glycol, methyl ethyl ketone (MEK), dimethylformamide (DMF), and the like.

In addition, although the said fluororesin composition is not specifically limited, 50-300 weight part of solvents may be included with respect to 100 weight part of fluororesins. At this time, when the content of the solvent is less than 50 parts by weight, the viscosity may be high and coating workability may be lowered. When the content of the solvent exceeds 300 parts by weight, curing (drying) may take a long time, which may be undesirable.

In the present invention, the fluorine resin is not limited as long as it contains fluorine (F) in the molecule. The fluorine resin may be one having durability and hydrolysis resistance. The fluorine resin is not limited as long as it contains fluorine (F) in the molecule. The fluororesin is, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) consisting of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, tetrafluoroethylene and hexafluoropropylene. At least one selected from polymers of tetrafluoroethylene and copolymers of ethylene or propylene, polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and the like. .

According to another embodiment of the present invention, the fluorine resin may use an ethylene-containing fluorine resin including ethylene together with fluorine in a molecule. The fluororesin is, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) consisting of a copolymer of tetrafluoroethylene and perfluoroalkylvinyl ether, tetrafluoroethylene and hexa One or more ethylene containing fluorine resins selected from polymers of fluoropropylene, copolymers of tetrafluoroethylene and ethylene or propylene, polychlorotrifluoroethylene (PCTFE) and the like can be used.

The ethylene-containing fluorine resins as listed above contain ethylene together with fluorine in the molecule, which is advantageous for improving adhesion with durability and hydrolysis resistance. Specifically, as described above, the encapsulation layer 220 (see FIG. 7) of the solar cell module may be composed of an ethylene vinyl acetate (EVA) sheet, wherein the ethylene-containing fluorine resin constitutes an ethylene vinyl acetate (EVA) sheet. Adhesion is improved by including ethylene as the homogeneous monomer. That is, the fluorine coating layer 24 is a surface layer 20, which is bonded to the encapsulation layer 220, wherein the fluorine coating layer 24 includes the encapsulation layer 220 when the fluorine coating layer 24 includes an ethylene-containing fluorine resin as listed above. It is bonded with high strength.

In addition, the ethylene-containing fluororesin may improve the adhesion between the substrate 10 and the layer. Specifically, the substrate 10 may include the polyester film layer 12 as described above. At this time, when the fluorine coating layer 24 as the surface layer 20 consists of ethylene-containing fluorine resin, it has the outstanding interlayer adhesiveness with the base material 10 comprised by the polyethylene type film layer 22. That is, the polyester film layer 12 as the substrate 10 may be composed of a polyethylene terephthalate film (PET film) or a polyethylene naphthalate film (PEN film). In this case, when the fluorine coating layer 24 is composed of an ethylene-containing fluorine resin, the polyester film layer 12 including ethylene as a homogeneous monomer constituting a polyethylene terephthalate film (PET film) or polyethylene naphthalate film (PEN film) ) And good interlayer adhesion.

In addition, the coating method and the number of times of coating of the fluororesin composition for forming the fluorine coating layer 24 are not limited. Fluorine resin compositions are, for example, spin coating, dip coating, bar coating, spray coating, ink-jet printing, gravure and The coating may be performed one or more times by one or more coating methods selected from screen-printing and the like.

According to another embodiment, when the surface layer 20 includes the fluorine coating layer 24, a primer layer 26 may be further formed on the fluorine coating layer 24.

FIG. 6 illustrates a fifth embodiment of the present invention, which illustrates the application of the surface layer 20 including the primer layer 26.

Specifically, referring to FIG. 6, the surface layer 20 may include a fluorine coating layer 24 formed on the substrate 10 and a primer layer 26 formed on the fluorine coating layer 24.

In this case, the primer layer 26 is to improve the adhesion between the fluorine coating layer 24 and the encapsulation layer 220, which is formed by coating a thin adhesive resin. Although the primer layer 26 is not specifically limited, it may have a thickness of 10 micrometers or less, for example, the thickness of 2-5 micrometers. The primer layer 26 may be formed by coating one or more adhesive resins selected from, for example, polyethylene, ethylene vinyl acetate (EVA), acrylic, urethane, and epoxy resins.

On the other hand, the heat dissipating fluorine paint coating layer 30 is formed on the other side of the substrate 10, which increases heat dissipation and at the same time improves durability. The heat dissipating fluorine paint coating layer 30 contains a heat dissipating material and a fluorine resin. Specifically, the heat dissipating fluorine coating layer 30 is formed by coating a coating composition containing a heat dissipating material and a fluorine resin on the substrate 10. At this time, the heat dissipating material may use a particulate, which acts as a heat conductive effective material for heat dissipation. And while the said fluororesin aims at durability, it also aims at the bonding force between particulate heat dissipation materials, and the adhesive force between a heat dissipation material, and the base material 10.

In the present invention, the heat radiating material may be one having thermal conductivity. The heat dissipating material may be one or more selected from, for example, carbon materials and metal particles.

At this time, the carbon material is not limited as long as it is a thermally conductive carbon body, for example, graphite (graphite), graphene (graphene), carbon nanotubes (CNT, carbon nano tube) and carbon nano fibers (CNF, carbon nano fiber) It may be used one or more selected from the group consisting of. Although this carbon material is not specifically limited, What has a particle size (diameter or length) of 200 micrometers or less, specifically, 0.1 nm (nanometer)-200 micrometers can be used.

In addition, the metal particles are not limited as long as they are thermally conductive metals, for example, aluminum (Al), gold (Au), silver (Ag), copper (Cu), nickel (Ni), tin (Sn), zinc ( Zn), one or more selected from the group consisting of tungsten (W) and iron (Fe) can be used. The metal particles may specifically use one single metal, two or more mixtures or two or more alloys (eg, stainless steel, etc.) selected from the metals listed above. Such metal particles are not particularly limited, but they may also be used having a particle size (diameter) of 200 μm or less, specifically, 0.1 nm (nanometer) to 200 μm.

In addition, the fluorine resin constituting the heat dissipating fluorine coating layer 30 is not limited as long as it has fluorine (F) in the molecule, which can be used, for example, as illustrated above. Specifically, the fluororesin is, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) consisting of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, tetrafluoroethylene and hexafluoro At least one selected from polymers of propylene, copolymers of tetrafluoroethylene and ethylene or propylene, polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF) Can be.

In addition, the heat dissipating fluorine paint coating layer 30 may be formed by coating a liquid or paste-like coating composition containing 5 to 70 parts by weight of the heat dissipation material with respect to 100 parts by weight of the fluorine resin. At this time, if the content of the heat dissipation material is less than 5 parts by weight, the thermal conductivity may be low because the thermal conductivity is too small. If the content is more than 70 parts by weight, the coating property is inferior and the content of the fluorine resin is relatively low. It may not be desirable.

The coating composition for forming the heat dissipating fluorine coating layer 30 may include a solvent for coating property in addition to the heat dissipating material and the fluorine resin. And as an additive may further include one or more selected from dispersants, antioxidants, sunscreens and antifoaming agents. In addition, the coating composition may further include a binder resin as necessary. Such a binder resin is for adhesion, and it may be selected from natural resins and synthetic resins. As the binder resin, at least one selected from resins such as polyesters, acrylics, epoxys, urethanes, ureas, and polyolefins (polyethylene, polypropylene, etc.) may be used.

In addition, the coating method and the number of times of coating of the coating composition for forming the heat dissipating fluorine coating layer 30 is not limited. The heat dissipating fluorine coating layer 30 may include, for example, spin coating, dip coating, bar coating, spray coating, ink-jet printing. One or more coatings selected from gravure, screen-printing, meyer bar coating, slot die coating, reverse coating and offset, etc. It may be formed by coating one or more times or two or more times.

In addition, the heat dissipating fluorine coating layer 30 is not particularly limited but may have a thickness of several tens of nanometers (nm) to 500 μm. At this time, if the thickness of the heat dissipating fluorine coating layer 30 is too low, the heat dissipation and durability improvement effect is insignificant, and partial heat dissipation may occur due to the surface scratching phenomenon caused by external impact. And when it exceeds 500㎛ may reduce the flexibility (flexible) of the back sheet 100 and may be undesirable in terms of price. In consideration of this point, the heat dissipating fluorine coating layer 30 may have a thickness of 0.1 μm to 300 μm, and more specifically, may have a thickness of 1.0 μm to 100 μm.

In addition, according to another embodiment, a primer layer may be further formed between the heat dissipating fluorine paint coating layer 30 and the substrate 10. The primer layer is for improving the adhesion between the heat dissipating fluorine paint coating layer 30 and the substrate 10, which is formed by a thin coating of the adhesive resin as described above. This primer layer is not particularly limited, but may have a thickness of 10 μm or less, for example, a thickness of 2 to 5 μm. As described above, the primer layer may be formed by coating one or more adhesive resins selected from polyethylene, ethylene vinyl acetate (EVA), acrylic, urethane, and epoxy resins.

In addition, according to another embodiment of the present invention, a separate layer may be further formed below the heat dissipating fluorine coating layer 30. For example, a protective layer for scratch resistance or the like may be further formed below the heat dissipating fluorine paint coating layer 30, and the protective layer may be selected from, for example, a polyester film.

Meanwhile, the solar cell module according to the present invention may include the back sheet 100 of the present invention as described above. 7 is a cross-sectional view showing an exemplary form of a solar cell module according to the present invention.

Referring to FIG. 7, the solar cell module according to the present invention may include the transparent member 210, the encapsulation layer 220, the solar cell C, and the back sheet 100 of the present invention as described above. have.

In this case, the transparent member 210 is to protect the upper side of the solar cell (C), which may be used for tempered glass, etc., which is advantageous for the incident light with the protection of the solar cell (C). In addition, the encapsulation layer 220 is capable of packing and fixing a plurality of electrically connected solar cells (C), which is illustrated in FIG. 7, which includes an upper encapsulation layer 221 and a lower encapsulation layer 222. It can be divided into. The encapsulation layer 220 may be composed of ethylene vinyl acetate (EVA) sheet.

In addition, the back sheet 100 is adhered to the lower portion of the encapsulation layer 220. More specifically, the surface layer 20 of the back sheet 100 is adhered to the lower surface of the lower encapsulation layer 222. In this case, the surface layer 20 and the lower encapsulation layer 222 may be bonded through heat fusion or an adhesive. The adhesive is not particularly limited, and for example, one or more adhesives selected from acrylic, urethane and epoxy resins can be used. The surface layer 20 and the lower encapsulation layer 222 may be preferably bonded by heat fusion.

As described above, according to the present invention, the heat dissipation fluorine paint coating layer 30 is included to have excellent durability and heat dissipation. Accordingly, the lifespan of the solar cell module can be extended, and the heat generated from the solar cell can be efficiently dissipated (discharged) to improve the power generation amount (light conversion efficiency) of the solar cell. In addition, according to the embodiment of the present invention, when the substrate 10 includes the metal layer 14, heat dissipation is further improved along with durability. In addition, when the surface layer 20 includes a polyethylene-based film layer 22 and / or a fluorine coating layer 24, it can be spread at a lower price than the conventional, adhesive and barrier properties (moisture barrier, etc.) This is excellent.

Hereinafter, the Example and comparative example of this invention are illustrated. The following examples are merely provided to aid the understanding of the present invention, whereby the technical scope of the present invention is not limited.

Example 1

10 parts by weight of titanium dioxide (TiO ₂ ) having an average particle size of 3 μm is mixed with respect to 100 parts by weight of polyethylene (PE), and then biaxially stretched by a conventional film forming method to obtain a white PE film having a thickness of 150 μm (hereinafter, ' W-PE film '. Then, both surfaces of the aluminum (Al) thin film of 80 μm were subjected to the anti-corrosion treatment, and then the W-PE film (PE + TiO ₂ ) prepared above was attached to one side thereof with an acrylic adhesive. Further, on the other side of the aluminum (Al) thin film, a heat-dissipating fluorine paint was gravure coated / coated to a thickness of 25 μm to prepare a back sheet having a laminated structure of a W-PE film / Al thin film / heat-resistant fluorine paint.

At this time, the anti-corrosion treatment was performed by treating the aluminum (Al) thin film with chromic acid at a thickness of about 1 μm, respectively. The heat dissipating fluorine paint used was a liquid coating composition containing tetrafluoroethylene (PTFE) and graphite powder in a weight ratio of 100: 50.

Example 2

A back sheet was manufactured in the same manner as in Example 1 except that a fluorine coating layer was formed instead of the W-PE film. That is, tetrafluoroethylene (PTFE) was coated on the surface of the corrosion protection layer formed on the Al thin film to have a thickness of 15 μm to prepare a back sheet having a laminated structure of fluorine coated / Al thin film / heat-resistant fluorine paint.

Example 3

A back sheet was manufactured in the same manner as in Example 2 except that two metal thin films were used. That is, the Al thin film having a thickness of 80 μm and the Cu thin film having a thickness of 50 μm were subjected to corrosion protection, and these were laminated with heat and pressure. Then, tetrafluoroethylene (PTFE) and a heat-dissipating fluorine coating composition were coated on both surfaces of the laminated metal thin film (Al / Cu thin film) in the same manner as in Example 2, whereby fluorine coating / Al thin film / Cu thin film / heat dissipation was applied. A back sheet having a laminated structure of fluorine paint was prepared.

[Comparative Example]

As a conventional back sheet, a back sheet having a laminated structure of a PVDF film / PET film / PVDF film by bonding a PVDF film (thickness 30 μm) to an acrylic adhesive on both sides of a PET film (thickness 250 μm) is used. It was used as a specimen.

For the back sheet specimens according to the above Examples and Comparative Examples, the durability, adhesion to EVA, moisture permeability, exothermic performance and the amount of power generation (%) were evaluated, and the results are shown in the following [Table 1].

(1) durability

For the back sheet specimens according to the examples and comparative examples, using a durability tester (Xenon Weather-Ometer, ATLAS Ci3000 +) using Xenon arc, at a constant temperature and humidity (80 ℃, 80% RH) 3000hr conditions The durability was evaluated according to the phosphorus method, and it was shown as excellent: (◎), good: (circle), and dissatisfaction: (triangle | delta).

(2) adhesion with EVA

The back sheet specimens according to the Examples and Comparative Examples were thermally bonded to the EVA sheet. At this time, each back sheet specimen was cut into A4 size, the EVA sheet was cut into a smaller size than the back sheet specimen, and superimposed and put into a hot air oven for 15 minutes at 150 ° C. for adhesion. And after taking out of the oven and cooling, it cut into 15 mm x 15 mm (width x length) size, and measured the peeling strength (adhesive force with EVA) between an EVA sheet and a back sheet.

(3) moisture permeability

The back sheet specimens according to each example and the comparative example were cut to a size of 15 mm x 15 mm (width x length) using a cutter bar, and then measured using a conventional moisture permeability meter.

(4) heating performance

Using an aluminum plate provided with a heat source (LED lamp) as a test object, a back sheet test piece according to each of Examples and Comparative Examples was attached to a test object set at an initial stage of 100 ?, and the test object temperature after 1 hour was measured and shown.

(5) Power generation amount (%)

The amount of solar cell power generation before the back sheet attachment was 100%, and the amount of power generation after the attachment was evaluated and expressed as a relative ratio before attachment.

Table 1 <Property Evaluation Results> Remarks Comparative example Example 1 Example 2 Example 3 Back sheet laminated structure PVDF Film / PET Film / PVDF Film W-PE / Al Thin Film / Heat Resistant Fluorine Paint Fluorine coating / Al thin film / Anti-heat fluorine paint Fluoride coating / Al thin film / Cu thin film / heat resistant fluorine paint durability ◎ ◎ ◎ ◎ EVA and adhesive force (kgf / 15㎜) Inability to peel Inability to peel Inability to peel Inability to peel Water vapor permeability (g / ㎡ · day) 2.4 0 0 0 Heat dissipation performance 100 ℃ 82 ℃ 84 ℃ 78 ℃ Generation amount (%) 100 115 113 118

As shown in Table 1, it is understood that the back sheet according to Examples 1 to 3 of the present invention has excellent durability as well as excellent adhesion to the EVA sheet as compared with the conventional comparative example. Could. In particular, compared with the conventional comparative example, it was found that the heat dissipation performance and the generation amount is very excellent. And as in Example 3, it can be seen that when using two metal thin films (Al / Cu thin film) having different thermal conductivity, the heat dissipation performance and the power generation is further improved.

[Description of the code]

10: base material 12: polyester film layer

14 metal layer 20 surface layer

22 polyethylene film layer 24 fluorine coating layer

30: heat dissipation fluorine coating layer 100: back sheet

210: transparent member 220: encapsulation layer

C: solar cell

Claims (16)

materials; A surface layer formed on one surface of the substrate; And It is formed on the other side of the said base material, The solar cell module back sheet containing the heat-dissipation fluorine-containing coating layer containing a heat dissipation material and a fluororesin. The method of claim 1, The substrate is a back sheet for a solar cell module, characterized in that it comprises at least one selected from a polyester film layer and a metal layer. The method of claim 1, The substrate is a back sheet for a solar cell module comprising a polyester film layer and a metal layer formed on the polyester film layer. The method of claim 1, The substrate comprises a metal layer, the metal layer is a solar cell module back sheet, characterized in that the two or more layers of different thermal conductivity. The method of claim 1, The substrate includes a metal layer, the metal layer is two or more layers, the metal constituting each layer is a back sheet for a solar cell module, characterized in that composed of a metal different from the adjacent layer. The method of claim 1, The surface layer is a solar cell module back sheet comprising a polyethylene film layer. The method of claim 6, The polyethylene film layer is a solar cell module back sheet, characterized in that it comprises a white inorganic material. The method of claim 1, The surface layer is a solar cell module back sheet comprising a fluorine coating layer. The method of claim 8, The fluorine coating layer is a solar cell module back sheet, comprising an ethylene-containing fluorine resin. The method of claim 8, The surface layer of the solar cell module back sheet further comprises a primer layer formed on the fluorine coating layer. The method of claim 1, The heat dissipating fluorine coating layer is a solar cell module back sheet, characterized in that it contains 5 to 70 parts by weight of heat dissipating material with respect to 100 parts by weight of fluorine resin. The method of claim 1, The heat dissipating material is at least one selected from a carbon material and metal particles. The method of claim 12, The carbon material is a solar cell module back sheet, characterized in that at least one selected from graphite, graphene, carbon nanotubes and carbon nanofibers. The method of claim 12, The metal particles are made of aluminum (Al), gold (Au), silver (Ag), copper (Cu), nickel (Ni), tin (Sn), zinc (Zn), tungsten (W) and iron (Fe). Solar cell module back sheet, characterized in that at least one selected from the group. The method of claim 1, The heat dissipating fluorine paint coating layer is a solar cell module back sheet, characterized in that it has a thickness of 0.1㎛ ~ 300㎛. A solar cell module comprising a back sheet according to any one of claims 1 to 15.

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