KR20140060385A - Back sheet for a solarcell having a controlled reflective property and module using the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a solar cell back sheet that effectively controls reflection characteristics and a solar cell module using the same, wherein the solar cell back sheet which controls the reflection characteristics of the present invention has a single layer, A solar cell back sheet formed by stacking films and formed of a base layer of a multilayer structure, wherein each layer is made of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PEN), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene Inorganic compound, and the surface of the substrate layer is formed with convex-shaped fine unevenness having a surface roughness (Ra) of 3 to 50 占 퐉.
The solar cell back sheet of the present invention having the above-described structure can be produced by applying a coating material containing particles on a surface of a base material layer or by transferring the shape of the base material layer to a resin, thereby forming convex fine irregularities of uniform surface roughness , The traveling path of sunlight incident on the solar cell can be efficiently controlled and the amount of light reflected on the back sheet and reaching the back surface of the biphenyl cell is increased. As a result, Controlled solar cell back sheet.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a solar cell back sheet and a solar cell module using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a solar cell back sheet that effectively controls reflection characteristics and a solar cell module using the same, more specifically, Thereby increasing the amount of light reaching the rear surface of the bifacial cell, thereby increasing the power generation efficiency of the solar cell module. In addition, Back sheet and a solar cell module using the same.

In recent years, photovoltaic solar cells have been attracting attention because of energy that does not cause environmental pollution, pollution-free, noiseless, and endless supply energy that overcomes the exhaustion crisis of limited energy resources and is environmentally friendly. This solar cell can convert light energy into electric energy using the photoelectric effect, and it can be divided into silicon system, compound system and organic system in terms of materials that convert light energy into electric energy. Of these, silicon solar cells are the most widely used, and compound systems are in the stage of mass production recently, organic systems are in the development stage and technological development is expected from a long-term perspective. In addition, silicon solar cells currently in common use are classified into crystalline silicon solar cells and amorphous silicon solar cells in more detail. Crystalline silicon solar cells, which are relatively superior in terms of mass productivity, conversion efficiency, and reliability, have.

Such a crystalline silicon solar cell is generally formed by sequentially laminating a reinforced glass, an ethylene vinyl acetate sheet, a cell, an ethylene vinyl acetate sheet, and a back sheet in this order, and it is possible to improve power generation efficiency have.

Therefore, a lot of research has been conducted on a method of improving power generation efficiency by reaching a plurality of solar cells to a cell. For example, Korean Patent Laid-Open Publication No. 2010-0071246 discloses a solar cell, A solar cell module comprising: a solar cell; A glass attached to a front surface of the solar cell; An infrared reflecting film disposed between the solar cell and the glass; And a back sheet having a reflective film attached to the back surface of the solar cell, wherein the glass is formed by forming a plurality of irregularities of a triangular prism structure on one surface of a back sheet for a solar cell, In selecting the material constituting the triangular prism structure, there is a problem in that it is difficult to select an industrial material which satisfies a refractive index characteristic which is important in the side of reflecting sunlight, in addition to a manufacturing method. As another example, Korean Patent Laid-Open Publication No. 2011-0084404 discloses a method for limiting the pitch between protrusions and recesses on the surface of a back sheet of a solar cell and improving the power generation efficiency of a solar cell. And a reflective layer having a refractive index of the reflective layer, wherein the reflective surface has a Gaussian curvature of zero at the reflective surface, and discloses a light-reusable sheet for a solar cell module. However, the above-mentioned irregularities on the surface of the back sheet and the pitch between the projections and depressions are focused on amorphous silicon solar cells, so-called thin film solar cells. For application to crystalline silicon solar cells, It is demanded to reduce the amount of water.

Patent Document 1: Korean Patent Publication No. 2010-0071246 Patent Document 2: Korean Patent Laid-Open Publication No. 2011-0084404

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solar cell backsheet which is free from problems in production technology and other problems, The present invention is to provide a solar cell back sheet capable of effectively controlling the traveling path of sunlight incident on a solar cell by forming convex-like fine concavities and convexities having a uniform surface roughness.

Another object of the present invention is to provide a solar cell module using the solar cell back sheet having the above-mentioned excellent characteristics.

It is still another object of the present invention to provide a method for easily manufacturing a solar cell back sheet having the above-described excellent characteristics.

The present invention may also be directed to accomplishing other objects that can be easily derived by those skilled in the art from the overall description of the present specification, other than the above-described and obvious objects.

In order to accomplish the above object, the present invention provides a solar cell backsheet,

In a solar cell back sheet formed by a single layer or a multi-layered base layer laminated with an electric insulating layer, a barrier layer and a weather resistant film,

Each of the layers may be formed of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyvinyl fluoride Wherein the surface layer is selected from the group consisting of polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE) Ra) of 3 to 50 mu m is formed on the surface of the substrate.

According to another aspect of the present invention, the convex-shaped fine irregularities are formed by coating a thermosetting binder resin, a curing agent, a solvent, and a coating material containing particles of two or more particles within a range of 3 to 50 mu m in particle diameter.

According to another aspect of the present invention, the convex-shaped fine unevenness is formed by applying a coating material containing a UV curable binder resin, a UV curing initiator, a solvent and at least two particles within a particle diameter of 3 to 50 μm do.

According to another aspect of the present invention, the two or more kinds of particles are characterized by being two types of particles: large diameter particles having a particle diameter in the range of 20 to 50 mu m and small diameter particles in the range of 3 to 20 mu m.

According to another embodiment of the present invention, the particles are selected from the group consisting of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE) And is formed of fluoroethylene (ECTFE).

According to another aspect of the present invention, the particle has a refractive index of 1.10 to 1.40.

According to another aspect of the present invention, the particles are spherical or spheroidal.

According to another aspect of the present invention, the fine unevenness is formed by transferring a shape to a resin using a frame capable of forming a spherical or elliptic convex shape having a surface roughness (Ra) of 3 to 50 탆 .

According to another embodiment of the present invention, the resin is selected from the group consisting of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE) And is formed of fluoroethylene (ECTFE).

According to another embodiment of the present invention, the resin has a refractive index of 1.10 to 1.40.

According to another aspect of the present invention, there is provided a method of manufacturing a solar cell back sheet,

(PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyvinyl fluoride (PVF), polyvinylidene fluoride Forming a monolayer or multi-layered substrate layer selected from the group consisting of ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE), or an inorganic compound; And

And forming convex convex-shaped concave and convex portions having a surface roughness (Ra) of 3 to 50 占 퐉 on one surface of the substrate layer.

According to another aspect of the present invention, the formation of the fine irregularities comprises:

A method of applying a coating material comprising a thermosetting binder resin, a curing agent, a solvent and at least two particles within a particle diameter of 3 to 50 mu m;

A method of applying a coating material comprising a UV curable binder resin, a UV curing initiator, a solvent and at least two particles within a particle diameter of 3 to 50 mu m; or

A method of transferring a block shape having a surface roughness in the range of 3 to 50 mu m to a resin by using a shape frame is formed.

According to another aspect of the present invention, there is provided a solar cell module comprising:

A solar cell module comprising a solar cell back sheet formed by a single layer or a multi-layered base layer laminated with an electrical insulating layer, a barrier layer and a weather resistant film, and a bi-facial cell, wherein each layer of the solar cell back sheet comprises polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyvinyl fluoride (PVF), polyvinylidene fluoride (Ra) is selected from the group consisting of tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE) or an inorganic compound, Shaped convexo-concave and convexo-concave concave and convexo-concave concave and convexo-concave.

The solar cell backsheet having the above-described reflection characteristics of the present invention, which has the above-described reflection characteristics, has a surface roughness of 3 to 50 占 퐉 It is possible to efficiently control the path of the sunlight incident on the solar cell and to increase the amount of light reflected on the back sheet and reaching the rear surface of the bifacial cell, A solar cell back sheet in which reflection characteristics are controlled so as to increase power generation efficiency of a module, and a solar cell including the back sheet, thereby solving the problems of the prior art.

1 is a cross-sectional view showing a schematic cross-section of a solar cell module according to an embodiment of the present invention,
2 is an explanatory diagram schematically illustrating the total reflection effect obtained by the present invention,
3 is an explanatory diagram schematically illustrating the light diffusion effect obtained by the present invention,
4 and 5 are cross-sectional views showing a schematic cross-section of a solar cell module according to another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail by way of preferred embodiments with reference to the accompanying drawings. However, it is needless to say that the present invention is not limited to the following embodiments, but can be modified into various forms within the scope of the gist of the present invention.

1 is a cross-sectional view showing a schematic cross section of a solar cell module according to a preferred embodiment of the present invention.

As shown in the figure, a solar cell module according to a preferred embodiment of the present invention is composed of a surface glass 1, a sealing material 2, a biaxial cell 3 and a back sheet layer 4. The back sheet layer 4 has a structure in which the reflective layer formed by fixing the large diameter particles 11 and the small diameter particles 12 to the polyethylene terephthalate layer 14 through the binder 13 is bonded to the white poly The other side of the white polypropylene layer 16 is bonded to one side of the propylene layer 16 and the other side of the white polypropylene layer 16 is bonded to the side of the hydrophilic polyethyleneterephthalate layer 17 in which the ultraviolet blocking layer 18 is formed through the adhesive layer 15 ).

Usually, the solar cell back sheet layer 4 is located on the back surface of the solar cell module. Among the solar light incident through the surface glass 1, light that has passed between the cell and the cell reaches the back sheet layer 4. At this time, it can be an effective means to improve the power generation efficiency of the solar cell module by controlling the reflection path of the light reaching the back sheet layer 4 to reach the rear surface of the biphenyl cell 3 Will be described in detail.

Figs. 2 and 3 are explanatory views showing an exemplary reflecting mirror according to the present invention. Fig. Fig. 2 shows a movement path in which light having passed between the cell and the cell is reflected to the rear surface of the bifacial cell through the total reflection phenomenon between the sealing material and the concave-convex micro concavo-convex due to the refractive index difference. In FIG. 3, light passing through the encapsulant is transmitted through the convex-shaped fine concavities and convexities, and reflected by the white polypropylene to reach the convex-shaped concavities and convexities again. In the convex-shaped micro concavo-convexes, since the light diffusion effect is realized, uniform light reaches the back surface of the bifacial cell. In the present invention, the above two effects are simultaneously implemented.

It is preferable that the convex-shaped fine unevenness has a surface roughness (Ra) of 3 to 50 mu m. When the surface roughness Ra is 3 탆 or less, light reaching the convex-shaped fine concavo-convex surface increases in a direction perpendicular to the surface of the convex-shaped concavo-convex surface, The amount of light that can reach the rear surface of the biphenyl cell decreases and the sufficient efficiency improvement of the solar cell module can not be obtained. When the surface roughness (Ra) is 50 탆 or more, the light diffusion effect is lowered, so that the light reflected from the white polypropylene can not reach the back surface of the bipyaxial cell at a uniform concentration.

It is preferable to use two or more kinds of particles within the range of 3 to 50 mu m in particle diameter. If the particle diameter is out of the range of 3 to 50 mu m, a preferable surface roughness (Ra) can not be obtained. Using only a single particle of a single size limits the variety of light travel paths, so that only limited light reaches the back surface of the bifacial cell and sufficient efficiency improvement can not be obtained.

It is particularly preferable that the particles use two kinds of particles of large diameter in the range of 20 to 50 mu m and small particles in the range of 3 to 20 mu m. When the diameter of the large diameter particles is 20 mu m or less, the amount of light transmitted perpendicularly to the convex-shaped fine concavities and convexities increases, so that sufficient efficiency improvement of the solar cell module can not be obtained. When the particle size of the small diameter particles is 20 m or more, the physical bonding force with the sealing material is deteriorated, so that the long-term reliability of the solar cell module can not be secured.

The large-diameter particles and the small-diameter particles preferably have a refractive index of 1.10 to 1.40. In general, ethylene vinyl acetate is used as an encapsulating material, and its refractive index is about 1.48. Reflection and transmission of light occur at the interface between ethylene vinyl acetate and large-diameter particles, ethylene vinyl acetate and small-diameter particles. Since light is totally reflected only at the interface between a high refractive index medium and a low refractive index medium, The total reflection effect can be obtained only when the refractive index is less than 1.48. In general, a material having a refractive index of 1.10 or less is not used for industrial use, and it is not preferable because material selection and supply and demand are difficult. When the refractive index is 1.40 or more, a difference in refractive index with ethylene vinyl acetate is not large, and thus the total reflection effect can not be sufficiently obtained.

The large diameter particles and the small diameter particles may be made of at least one selected from the group consisting of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene ). The resin has a refractive index of about 1.35, which is advantageous in that it can be easily supplied and received.

The large diameter particles and the small diameter particles are preferably spherical or ellipsoidal. In such a case, the total reflection effect and the light diffusion effect can be realized at the same time, which is preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but it goes without saying that the scope of the present invention is not limited to these Examples.

Example 1

A coating liquid having the following composition was applied on the surface of a PET base film (Toray Advanced Material Co., Ltd. XU42, 125 mu m) using a gravure coater so as to have a coating amount of 15 g / m 2 to form convex-shaped fine irregularities.

Composition of coating liquid for formation of fine unevenness of convex shape

- Binder resin (Aekyung A811): 29.0 wt%

- Thermal reaction curing agent (Aekyung DN980S): 3.0 wt%

ETFE particles having an average diameter of 30 占 퐉: 6.0 wt%

ETFE particles having an average diameter of 7 占 퐉: 6.0 wt%

- methyl ethyl ketone: 28.0 wt%

- Toluene: 28.0 wt%

The adhesive was coated on the other side of the PET base film by a gravure coater using an adhesive for dry lamination (DIC, subject: TSB-710, curing agent: TSB-900) B011W, 100 mu m).

A coating liquid having a composition characterized in that an ultraviolet absorber and a light stabilizer (HALS) were crosslinked on the surface of another PET base film (Doresay X10S, 75 탆) was applied to the acrylic polyol resin using a gravure coater so as to have a coating amount of 7 g / To give ultraviolet shielding properties.

Composition of coating liquid for imparting ultraviolet shielding property

- Theme (BK1, manufactured by Nippon Shokubai Chemical Co., Ltd.): 45.0 wt%

- Curing agent (Sumika Bayer Urethane N3200): 4.5 wt%

- ethyl acetate: 50.5 wt%

On the other side of the PP film, an adhesive for dry lamination (DIC, subject: TSB-710, curing agent: TSB-900) was applied by a gravure coater to a thickness of 5 μm and the ultraviolet- . Thereby forming a solar cell back sheet having a PET / PP / PET structure.

Then, a solar cell module was fabricated using a glass laminator in the order of tempered glass, ethylene vinyl acetate, bifacial cell, ethylene vinyl acetate, and the solar cell back sheet.

Example 2

On the surface of the PP film (Toray advanced Film Company B011W, 100 mu m), a coating liquid having the following composition was applied using a gravure coater so as to have a coating amount of 15 g / m 2 to form convex-shaped fine irregularities.

Convex  Composition of coating liquid for fine unevenness formation

- Binder resin (Aekyung A811): 29.0 wt%

- Thermal reaction curing agent (Aekyung DN980S): 3.0 wt%

ETFE particles having an average diameter of 30 占 퐉: 6.0 wt%

ETFE particles having an average diameter of 7 占 퐉: 6.0 wt%

- methyl ethyl ketone: 28.0 wt%

- Toluene: 28.0 wt%

A coating liquid having a composition characterized in that an ultraviolet absorber and a light stabilizer (HALS) were crosslinked to the acrylic polyol resin on the surface of another PET base film (Doresay X10S, 75 탆) was coated with a gravure coater so as to have a coating amount of 8 g / To give ultraviolet shielding properties.

Composition of coating liquid for imparting ultraviolet shielding property

- Theme (BK1, manufactured by Nippon Shokubai Chemical Co., Ltd.): 45.0 wt%

- Curing agent (Sumika Bayer Urethane N3200): 4.5 wt%

- ethyl acetate: 50.5 wt%

On the other side of the PP film, an adhesive for dry lamination (DIC, subject: TSB-710, curing agent: TSB-900) was applied by a gravure coater to a thickness of 5 μm and the ultraviolet- . Thereby forming a solar cell back sheet having a PP / PET structure.

Then, using a glass laminator, a solar cell module was fabricated in the order of tempered glass, ethylene vinyl acetate, bifacial cell, ethylene vinyl acetate, and the above solar cell back sheet.

Example 3

A coating liquid having the following composition was applied on the surface of a PET film (Toray Films Europe Corp. XTRMPVW, 250 m) having hydrolysis resistance and ultraviolet shielding properties so as to have a coating amount of 15 g / m 2 using a gravure coater to obtain convex- Thereby forming a solar cell back sheet having the formed PET monolayer structure.

Convex  Composition of coating liquid for fine unevenness formation

- Binder resin (Aekyung A811): 29.0 wt%

- Thermal reaction curing agent (Aekyung DN980S): 3.0 wt%

ETFE particles having an average diameter of 30 占 퐉: 6.0 wt%

ETFE particles having an average diameter of 7 占 퐉: 6.0 wt%

- methyl ethyl ketone: 28.0 wt%

- Toluene: 28.0 wt%

Then, a solar cell module was fabricated using a glass laminator in the order of tempered glass, ethylene vinyl acetate, bifacial cell, ethylene vinyl acetate, and the solar cell back sheet.

Comparative Example 1

A solar cell back sheet excluding the use of a PET base film having convex-shaped fine concavities and convexities was produced in the same manner as in Example 1, and a solar cell module to which the solar cell back sheet was applied was fabricated.

Comparative Example 2

A solar cell back sheet using a PP film having no convex-shaped fine irregularities was produced in the same manner as in Example 2, and a solar cell module to which the solar cell back sheet was applied was fabricated.

Comparative Example 3

A solar cell module was manufactured in the same manner as in Example 3 except that a PET film having no irregularities and no hydrolysis resistance and ultraviolet light blocking properties was applied as a solar cell back sheet.

Experimental Example 1

The current-voltage characteristics of the solar cells fabricated in each of the Examples and Comparative Examples were measured using a solar simulator (light intensity: 1 kW / m 2, spectrum: AM 1.5 global) in an atmosphere of 25 ° C.

Maximum output
(W) Maximum operating voltage
(V) Maximum operating current
(A) Module efficiency
(%) Example 1 262 32.0 8.2 16.2 Example 2 258 31.9 8.1 15.9 Example 3 250 31.3 8.0 15.7 Comparative Example 1 258 31.8 8.1 15.6 Comparative Example 2 254 31.7 8.0 15.2 Comparative Example 3 246 31.1 7.9 15.0

From the results shown in Table 1, it can be seen that, when convex fine irregularities are formed on the back sheet surface, the contrast module efficiency increases when the convex fine irregularities are not formed. That is, by forming convex fine concavities and convexities on the surface of the back sheet, the amount of light reaching the back surface of the bifacial cell is increased, and convex-like fine irregularities are formed in the back sheet of the present invention, The ability to efficiently control the path reflected from the sheet proved to be valid.

1 --- Surface glass 2 --- Encapsulant
3 --- Biphasic cell 4 --- Back sheet layer
5 --- back sheet layer 6 --- back sheet layer
11 --- Large diameter particle
12 --- Small particle
13 --- Binder Resin
14 --- Polyethylene terephthalate layer
15 --- Adhesive layer
16 --- white polypropylene layer
17 --- The hydrolyzable polyethylene terephthalate layer
18 --- UV barrier layer
19 --- The hydrolyzable polyethylene terephthalate layer

Claims (13)

In a solar cell back sheet formed by a single layer or a multi-layered base layer laminated with an electric insulating layer, a barrier layer and a weather resistant film,
Each of the layers may be formed of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyvinyl fluoride (PVF), polyvinylidene fluoride Wherein the surface layer is selected from the group consisting of polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE) Ra) of 3 to 50 占 퐉 is formed on the back surface of the solar cell back sheet.
The method according to claim 1, wherein the convex-shaped fine unevenness is formed by applying a coating material comprising a thermosetting binder resin, a curing agent, a solvent, and at least two particles within a particle diameter range of 3 to 50 mu m A solar cell back sheet.
The reflective film according to claim 1, wherein the convex-shaped fine irregularities are formed by applying a coating material containing a UV curable binder resin, a UV curing initiator, a solvent and at least two particles within a particle diameter range of 3 to 50 mu m The solar cell back sheet.
The method according to claim 2 or 3, wherein the two or more kinds of particles are two types of particles: large-diameter particles having a particle diameter in the range of 20 to 50 μm and small-diameter particles in the range of 3 to 20 μm Battery back sheet.
4. The method of claim 2 or 3, wherein the particles are selected from the group consisting of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE) (ECTFE). The solar cell backsheet according to any one of claims 1 to 3,
The solar cell backsheet according to claim 2 or 3, wherein the particles have a refractive index of 1.10 to 1.40.
The solar cell back sheet according to claim 2 or 3, wherein the particles are spherical or ellipsoidal in shape.
[2] The method according to claim 1, wherein the fine unevenness is formed by transferring a shape to a resin using a mold capable of forming a spherical or elliptical convex shape having a surface roughness (Ra) of 3 to 50 占 퐉 Solar cell back sheet that controls reflection characteristics.
The method of claim 8 wherein the resin is selected from the group consisting of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE) of the solar cell.
The solar cell back sheet according to claim 8, wherein the resin has a refractive index of 1.10 to 1.40.
(PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyvinyl fluoride (PVF), polyvinylidene fluoride Forming a monolayer or multi-layered substrate layer selected from the group consisting of ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE), or an inorganic compound; And
And forming convex convexo-concave portions having a surface roughness (Ra) of 3 to 50 占 퐉 on one surface of the base layer.
12. The method according to claim 11, wherein the formation of the fine irregularities comprises:
A method of applying a coating composition comprising a thermosetting binder resin, a curing agent, a solvent and at least two particles within a particle diameter of 3 to 50 mu m;
A method of applying a coating material comprising a UV curable binder resin, a UV curing initiator, a solvent and at least two particles within a particle diameter of 3 to 50 mu m; or
And transferring a block shape having a surface roughness in the range of 3 to 50 占 퐉 to the resin using a shape frame. The method for manufacturing a solar cell back sheet according to claim 1,
A solar cell module comprising a solar cell back sheet formed by a single layer or a multi-layered base layer laminated with an electrical insulating layer, a barrier layer and a weather resistant film, and a bi-facial cell, wherein each layer of the solar cell back sheet comprises polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyvinyl fluoride (PVF), polyvinylidene fluoride (Ra) is selected from the group consisting of tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE) or an inorganic compound, Wherein the convex-shaped concave and convex portions of the concave and convex-shaped concave and convex portions are formed.

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