JP2014157874A - Solar battery module and method of manufacturing the same - Google Patents

Abstract

A solar cell module capable of preventing deterioration of characteristics due to a PID phenomenon and realizing good laminate sealing.
A solar cell (crystalline silicon solar cell 105) using a crystalline semiconductor substrate having an insulating film formed on the surface on the light receiving surface side is provided between the light receiving surface side protective glass 101 and the back surface side protective member 107. The solar cell module 100 is sealed with the insulating film side facing the light receiving surface side protective glass 101 side, and the light receiving surface is interposed between the light receiving surface side protective glass 101 and the solar cell 105. From the side protective glass 101 side, an ionomer resin layer 102, a transparent resin layer 103 having irregularities on both surfaces, and an ethylene-vinyl acetate copolymer resin layer 104 are laminated in this order.
[Selection] Figure 1

Description

  The present invention relates to a solar cell module and a manufacturing method thereof, and particularly to a solar cell module in which crystalline solar cells are sealed with a weather-resistant member and a manufacturing method thereof.

  In recent years, a large-scale solar power generation system called a mega solar that installs a large number of crystalline silicon solar cell modules on a large site and constructs a solar power generation system for electric power business has been rapidly increasing. In such a large-scale photovoltaic power generation system, in order to simplify wiring work between solar cell modules and reduce costs by reducing the number of wires and connection boxes, a large number of solar cell modules are connected in series, and the maximum system voltage is increased. It is often designed as high as 600V to 1000V. However, in such a crystalline silicon solar power generation system having a high system voltage, a sudden characteristic deterioration phenomenon called PID (Potential Induced Degradation) may occur in the crystalline silicon solar cell module, which is a problem.

  Regarding the PID phenomenon of such a crystalline silicon solar cell module, the cause and generation mechanism have not yet been elucidated. However, the PID phenomenon is likely to occur and progress when a high system voltage is applied to the solar cell module, and when it is in a high temperature and high humidity state, and the characteristics are restored by applying a high voltage in the reverse direction to the solar cell module. It has been reported to do.

  Hereinafter, a mechanism in which the PID phenomenon occurs in a crystalline silicon solar battery module using a crystalline silicon solar battery cell configured using a general P-type wafer will be described. The surface of the crystalline silicon solar cell module is generally covered with a cover glass made of soda lime glass. Here, if there is moisture on the surface of the cover glass, sodium ions (Na + ions) that are metal ions are generated from the soda lime glass. Usually, the cover glass of the crystalline silicon solar cell module is supported by a metal frame, and the metal frame is connected to the ground and has a ground potential.

  When a negative system voltage is applied to the internal wiring of the crystalline silicon solar cell module in such a state, a large potential difference is generated inside and outside the crystalline silicon solar cell module. Na + ions (metal ions) on the surface of the cover glass move in the cover glass or in the sealing filling resin due to this potential difference, and reach the surface of the crystalline silicon solar cell. Under the conditions of high temperature and high humidity, the volume resistance of the cover glass and the sealing filling resin is decreased, the leakage current is increased, and Na + ions (metal ions) are easily moved.

  Usually, the surface of the doped layer (N-type) on the light incident side of the crystalline silicon solar battery cell is covered with an insulating passivation film. This passivation film is polarized by the attachment of charged ions. As a result, a polarity reversal region (P type) is formed in the vicinity of the interface between the doped layer (N type) of the light incident side of the crystalline silicon solar cell and the passivation layer, the movement of photogenerated carriers is prevented, and the cell characteristics are improved. descend.

  As a method for preventing the occurrence of such a PID phenomenon, several methods have been proposed so far. For example, as a method for dealing with solar power generation systems, use an inverter with an insulation transformer and ground the negative electrode of the inverter input so that the inside of the solar cell module does not become negative with respect to the outside. It has been known. However, in recent years, transformer-less has been progressing for higher efficiency and cost reduction of inverters, and it is becoming difficult to cope with such systems.

  On the other hand, as a method for dealing with solar cell modules, for example, Non-Patent Document 1 discloses that PID is suppressed by using ionomer instead of ethylene vinyl acetate (EVA) as a sealing resin. Has been. Further, for example, in Patent Document 1, in a solar cell module in which solar cells are sealed using EVA, in order to prevent water vapor from entering the inside of the solar cell module, the side opposite to the solar cell of EVA resin is disclosed. Discloses a structure in which an ionomer resin layer is provided. According to the sealing structure of the solar cell combining the ionomer and EVA disclosed in Patent Document 1, leakage current from the cover glass and invasion of Na + ions (metal ions) are prevented, and the occurrence of the PID phenomenon is prevented. be able to.

JP 2011-77172 A

P. Hacke, et. Al ”Characterization of Multicrystalline Silicon Modules with System Bias Voltage Applied in Damp Heat”, 25th European Photovoltaic Solar Energy Conference and Exhibition, Valencia, Spain, 2010

  However, the solar cell module having the structure disclosed in Patent Document 1 has the following problems. That is, in order to seal and laminate solar cells, the EVA sheet and the ionomer sheet are overlaid and heated and bonded, but the process temperature conditions (laminating conditions) such as the heating temperature and the presence or absence of curing are used with EVA and ionomer. ) Is different, and the size of thermal expansion and contraction is also different. For this reason, problems such as bubbles are likely to remain at the interface between EVA and ionomer, areas of a mixture of EVA and ionomer are likely to occur, and wrinkles and undulation are likely to occur on the bonding surface of EVA and ionomer. It was extremely difficult to laminate and seal the solar battery cells satisfactorily.

  This invention is made | formed in view of the above, Comprising: It aims at obtaining the solar cell module which can implement | achieve favorable laminate sealing, and its manufacturing method while the characteristic fall by a PID phenomenon is prevented.

  In order to solve the above-described problems and achieve the object, the solar cell module according to the present invention is provided with a solar cell using a crystalline semiconductor substrate in which an insulating film is formed on the light-receiving surface side. A solar cell module sealed between the glass and the back surface side protective member with the insulating film side facing the light receiving surface side protective glass side, between the light receiving surface side protective glass and the solar battery cell In addition, an ionomer resin layer, a transparent resin layer having irregularities on both surfaces, and an ethylene-vinyl acetate copolymer resin layer are laminated in this order from the light receiving surface side protective glass side.

  According to the present invention, it is possible to obtain a solar cell module that can prevent deterioration in characteristics due to the PID phenomenon and can realize good laminate sealing.

FIG. 1 is a main part sectional view schematically showing a schematic configuration of a crystalline silicon solar cell module according to a first embodiment of the present invention. FIG. 2 is a characteristic diagram showing the relationship between the average surface roughness Ra (μm) of the transparent resin film sheet and the adhesive strength between the ionomer resin. FIG. 3-1 is a plan view of the crystalline silicon solar battery cell according to the first embodiment of the present invention viewed from the light receiving surface side. FIG. 3-2 is a plan view of the crystalline silicon solar battery cell according to the first embodiment of the present invention as viewed from the non-light-receiving surface side (back surface side). 3-3 is principal part sectional drawing which shows the structure of the crystalline silicon solar cell concerning Embodiment 1 of this invention, and is AA sectional drawing in FIGS. FIGS. 3-4 is principal part sectional drawing which shows the string by which the crystalline silicon photovoltaic cell concerning Embodiment 1 of this invention was electrically connected and connected by the connection wiring in series. FIG. 4 is a cross-sectional view of an essential part schematically showing a schematic configuration of a conventional solar cell module. FIG. 5: is principal part sectional drawing which shows typically schematic structure of the crystalline silicon solar cell module concerning Embodiment 3 of this invention.

  Embodiments of a solar cell module according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings.

Embodiment 1 FIG.
FIG. 1 is a main part sectional view schematically showing a schematic configuration of a crystalline silicon solar cell module 100 (hereinafter sometimes referred to as a solar cell module 100) according to a first embodiment of the present invention. As shown in FIG. 1, the solar cell module 100 according to the first embodiment has a light-receiving surface side protective glass 101 that is a weather-resistant member, an ionomer resin layer 102, and irregularities on both surfaces from the incident side of sunlight L. Transparent resin film sheet 103, which is a transparent resin layer, EVA resin layer 104, crystalline silicon solar battery cell 105 (hereinafter sometimes referred to as solar battery cell 105), EVA resin layer 106, and backside protection which is a weather-resistant member The members 107 are laminated in this order, and have a structure integrated by a laminating process. In addition, the crystalline silicon solar cell module 100 in which these members are laminated and integrated is supported by a frame-shaped aluminum frame, which is a metal frame (not shown), and fixed to an electrically grounded frame. ing. That is, the metal frame is set to the installation potential.

  In one crystalline silicon solar cell module 100, 60 crystalline silicon solar cells 105 are electrically connected in series with the electrodes provided on the front and back of each crystalline silicon solar cell 105. It is wired so that it is a string. The open voltage of the crystalline silicon solar cell module 100 in the standard state is about 36 V, and the output is output to a cable (not shown).

In the present embodiment, the light receiving surface side protective glass 101 is a plate glass that covers the light receiving surface side (light incident side) surface of the crystalline silicon solar cell module 100. Such a plate glass is preferably a white plate tempered glass having a high light transmittance and a low iron content, which has sufficient wind pressure resistance and weather resistance strength as a solar cell module, and more preferably its light incident side surface. It is a white plate tempered glass provided with a low refractive index antireflection layer such as porous silica. In addition, as the light-receiving surface side protective glass of the solar cell module for terrestrial power generation, general soda lime glass mainly composed of silicon oxide (SiO ₂ ), sodium oxide (NaO), and calcium oxide (CaO) is used. Expensive borosilicate glass and quartz glass are not used. For this reason, it is difficult to completely eliminate the generation of Na + ions (metal ions) from the light-receiving surface side protective glass.

  In this embodiment, the ionomer resin is a non-crosslinked thermoplastic resin, and zinc (Zn) or sodium (Na) is used between the ethylene-methacrylic acid copolymer and the ethylene-acrylic acid copolymer. A resin having a structure in which molecules are bonded by metal ions, and is supplied as a resin film sheet and laminated with other materials. Specific examples include DuPont's trade name Surlyn (registered trademark) and Mitsui-DuPont Polychemical trade name Himiran (registered trademark).

In the present embodiment, the transparent resin film sheet 103 having irregularities on both surfaces,
A resin film sheet made of a transparent resin such as polyethylene terephthalate (PET). The transparent resin film sheet 103 has appropriate uneven shapes on both surfaces. The average surface roughness Ra at the reference length of concavo-convex on the surface on the side in contact with the ionomer resin in the transparent resin film sheet 103 is preferably in the range of about 2 μm to 20 μm.

  PET has a thermal deformation temperature of about 240 ° C., and even if EVA or ionomer resin is softened by heating in the solar cell sealing step (laminating step), the PET film sheet is not deformed. The heating temperature in the laminating process is about 150 to 170 degrees. Therefore, in the heating in the sealing process, the softened EVA or ionomer resin flows to fill the irregularities on the surface of the PET film sheet, and the PET film sheet and EVA, the PET film sheet, and the ionomer resin are bonded. Thereby, the adhesive strength of the transparent resin film sheet 103 and the ionomer resin layer 102 and the transparent resin film sheet 103 and the EVA resin layer 104 is improved.

  FIG. 2 is a characteristic showing the relationship between the average surface roughness (arithmetic average roughness) Ra (hereinafter sometimes referred to as average surface roughness Ra) (μm) (μm) of the transparent resin film sheet and the bond strength between the ionomer resin layers. FIG. FIG. 2 shows a result of the inventor producing a sample in which a light-receiving surface side protective glass, an ionomer resin layer, and a transparent resin film sheet (PET resin sheet) are laminated, and performing a tensile test based on JIS K6849. .

  In FIG. 2, the horizontal axis represents the average surface roughness Ra (μm) of the PET resin sheet, and the vertical axis represents the relative value of the adhesive strength between the ionomer resin layer and the transparent resin film sheet when the maximum strength is 1.0. . 5 samples each having an average surface roughness of 0 μm, 1 μm, 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, and 35 μm are prepared for each of the transparent resin film sheet (PET resin sheet), and the adhesive strength Was measured. In FIG. 2, the dispersion of the adhesive force at each average surface roughness Ra is indicated by a vertical bar, and the line connecting the average values of the measured adhesive force values at each average surface roughness is indicated by a broken line.

From the results shown in FIG. 2, the present inventor shows that the adhesive strength between the ionomer resin layer and the transparent resin film sheet becomes maximum (maximum strength) when the average surface roughness Ra of the transparent resin film sheet is in the range of about 2 μm to 20 μm. I found this experimentally. In this experiment, when the average surface roughness of the transparent resin film sheet is 0 μm, that is, when the surface of the transparent resin film sheet is not uneven and the surface is smooth, the adhesive force between the ionomer resin layer and the transparent resin film sheet is The value was as low as about 9 N / cm ² .

Although there is no standard for the adhesive strength of a sheet such as a sealing material in the solar cell module certification test, the solar cell module is currently a size that can be manually installed and has an area of about 1.5 m ² and a weight of about 15 kg to 20 kg. The form is the most common. In such a solar cell module, as a case where a large force is applied to the bonding surface of the sealing material or the like, a situation where the solar cell module is suspended only by the cable coming out of the terminal box can be considered. In this situation, a solar cell module by weight about 20 kg, assuming the adhesion area of the terminal box approximately 20 cm ^2, the lamination stack of the adhesive portion of the terminal box, the tensile force is applied for about 10 N / cm ² It will be.

Therefore, in the case where the ionomer resin layer and the transparent resin film sheet have no unevenness on the surface of the transparent resin film sheet described above, the adhesive strength between the transparent resin film sheet and the transparent resin film sheet is about 9 N / cm ² . There is a high risk of the adhesive surface between the ionomer resin layer and the transparent resin film sheet being peeled off and destroyed. However, in general, if the adhesive strength between the ionomer resin layer and the transparent resin film sheet is 20 N / cm ² or more, which is approximately twice this, due to mechanical pulling force that can usually be considered or expansion and contraction due to temperature changes, etc. The adhesive surface between the ionomer resin layer and the transparent resin film sheet does not peel off, and an adhesive strength of 20 N / cm ² or more is considered as a practical adhesive strength.

In the experimental result shown in FIG. 2, the relative adhesive strength when the average surface roughness Ra = 0 of the PET resin sheet is 0.3, and this strength is 9 N / cm ² . In the figure, the range of the average surface roughness Ra at which an adhesive strength of 20 N / cm ² or more that is practical as a solar cell module is obtained is as follows: Adhesive strength 20 N / cm ² = average surface roughness at which the relative adhesive strength is 0.7 or more. The range of Ra, that is, the average surface roughness Ra was found to be in the range of about 2 μm to 20 μm.

  The reason why the adhesive force between the transparent resin film sheet and the ionomer resin layer shows a peak with respect to the average surface roughness Ra of the transparent resin film sheet is considered to be as follows. In the surface of the transparent resin film sheet, in a region having fine irregularities with an average surface roughness Ra <5 μm, sufficient adhesive force cannot be obtained for the following reason. That is, when the unevenness with a small height difference is on the entire surface of the transparent resin film sheet, the surface of the transparent resin film sheet is smoothed by heating and pressurizing at the time of lamination. Fades. In addition, on the surface of the transparent resin film sheet, when uneven portions having a certain level of height difference or more are mixed microscopically in the smooth surface, the adhesive strength with the ionomer resin layer of the smooth surface is low. It is considered that sufficient adhesive strength cannot be obtained due to the influence.

  On the other hand, on the surface of the transparent resin film sheet, in a region having relatively large irregularities with an average surface roughness Ra> 20 μm or more, sufficient adhesive force cannot be obtained for the following reason. That is, for example, when the average surface roughness Ra is increased without changing the shape of the pyramidal shape with an apex angle of 60 degrees, the surface is covered with a large unevenness pattern (pyramid shape, etc.), so The number of concavo-convex patterns decreases. In this case, since the surface area of the adhesion surface between the transparent resin film sheet and the ionomer resin layer does not change and the anchoring effect (anchor effect) is reduced, the adhesive force between the transparent resin film sheet and the ionomer resin layer is reduced. Also, if the height difference is increased without changing the density of the uneven pattern, only the height difference of the finely distributed uneven pattern increases, making it difficult for the high viscosity ionomer to enter and adhere to the deeply uneven surface, It is considered that the adhesive strength is reduced.

  When measuring the average surface roughness Ra, if the measurement is performed under a condition where the reference length is long, the average surface roughness Ra includes a long-period undulation instead of the surface roughness. Therefore, in the present embodiment, the reference length of the average surface roughness Ra is defined as 0.25 mm. For example, when the average surface roughness Ra is measured with a reference length of 8 mm, the surface of the transparent resin film sheet is gently wavy, and when the period is 4 mm and the triangular waveform is 80 μm in height, the average surface roughness Although Ra = 20 μm, the concavo-convex shape has a height of only 1/50 with respect to the lateral length, and an improvement in the adhesive strength cannot be expected.

  The irregularities on the surface of the transparent resin film sheet 103 are preferably formed almost uniformly over the entire surface. The uneven shape on the surface of the transparent resin film sheet 103 is preferably a cross-sectional shape that hardly causes light scattering and can increase the adhesion surface area. Specifically, examples of the uneven cross-sectional shape of the surface of the transparent resin film sheet 103 include an irregular texture shape, a regular triangular wave shape, and a rectangular wave shape.

  In addition, as a method of forming a concavo-convex shape on the surface of the transparent resin film sheet 103, a method of transferring a concavo-convex shape by pressing a heat roller having a concavo-convex shape on the surface at the time of sheet formation, sand blasting on the surface of the transparent resin film sheet 103 Or a method of mechanically forming irregularities by laser beam irradiation.

  Further, the thickness of the transparent resin film sheet 103 is preferably 20 μm or more on average in order to form moderate irregularities on the surface, and the average thickness in order not to increase the light absorption loss in the transparent resin film sheet 103. It is preferable that it is 200 micrometers or less.

  In the present embodiment, the EVA resin layers 104 and 106 are ethylene-vinyl acetate copolymer resins that are generally used in solar cell modules. When the module is manufactured, the EVA resin layers 104 and 106 and the ionomer resin layer 102 are heated and laminated at the same time. Therefore, it is preferable that the lamination temperature and the curing temperature do not differ greatly.

  In the present embodiment, the crystalline silicon solar battery cell 105 is a single crystal or polycrystalline silicon solar battery cell that forms a PN junction by general impurity diffusion. Here, the configuration of the crystalline silicon solar battery cell 105 will be described. The crystalline silicon solar battery cell 105 is typically a crystalline silicon cell using a polycrystalline silicon substrate or a single crystal silicon substrate having p-type conductivity as a photoelectric conversion layer.

Note that, in the solar cell module 100 according to the present embodiment, the solar cell sealed inside is not limited to this, and is a crystalline silicon cell using an n-type silicon substrate, an amorphous material on the crystalline silicon substrate. It is also possible to use a heterojunction silicon cell in which a silicon layer is formed or a compound cell typified by gallium arsenide (GaAs). Furthermore, it is also possible to use a back electrode type (IBC: Interdigitated Back Contact) cell having a structure in which a metal electrode normally formed on the light receiving surface side of the substrate is formed on the back surface side of the substrate. However, a passivation layer (antireflection layer) of insulating SiN _x , SiO _x or the like is provided on the light incident side of these solar cells.

  Here, as a typical crystalline silicon solar battery cell 105, a crystalline silicon photoelectric conversion cell using a single crystal silicon substrate having p-type conductivity as a photoelectric conversion layer will be described. FIG. 3A is a plan view of the crystalline silicon solar battery cell 105 according to the first embodiment when viewed from the light receiving surface side. FIG. 3-2 is a plan view of the crystalline silicon solar battery 105 according to the first embodiment when viewed from the non-light-receiving surface side (back surface side). FIG. 3-3 is a principal part sectional view showing the configuration of the crystalline silicon solar battery 105 according to the first embodiment, and is a sectional view taken along line AA in FIG. 3-1. 3-4 is a cross-sectional view of a principal part showing a string in which the crystalline silicon solar battery cells 105 according to the first embodiment are electrically connected and connected in series by the connecting wires 21.

  As the crystalline silicon solar cell 105, a single-sided power generation type crystalline solar cell which is a typical super straight type can be used. The crystalline silicon solar battery 105 is a substrate having a photoelectric conversion function and is formed of, for example, a silicon nitride film as an insulating film on the light receiving surface side of the semiconductor substrate 7 having a pn junction, and is used for antireflection and surface passivation. A film 3 is formed. Semiconductor substrate 7 has an impurity diffusion layer (n-type impurity diffusion layer) 2 formed by phosphorous diffusion on the light-receiving surface side of semiconductor substrate 1 made of, for example, p-type single crystal silicon. On the light receiving surface side and the back surface side of the semiconductor substrate 7, a light receiving surface bus electrode 52 and a back surface bus electrode 62 are formed as connection electrodes for bonding to the connection wiring 21. In this solar cell 105, sunlight L enters from the antireflection film 3 side.

  On the light receiving surface side surface of the semiconductor substrate 1 (n-type impurity diffusion layer 2), an inverted pyramid texture structure (not shown) made of, for example, minute pyramids (textures) having an inverted pyramid shape is formed as a texture structure. The inverted pyramid-shaped micro unevenness (texture) increases the area that absorbs light from the outside on the light receiving surface, suppresses the reflectance on the light receiving surface, efficiently confines light in the solar cell 105, and extends the optical path length. Improve output current.

  On the light-receiving surface side of the semiconductor substrate 7, the light-receiving surface electrode 5, which is a metal electrode having a comb shape formed by baking an electrode material containing silver (Ag) and glass, penetrates the antireflection film 3 and diffuses impurities. The layer (n-type impurity diffusion layer) 2 is provided in electrical connection. As the light receiving surface electrode 5, a plurality of long and narrow light receiving surface grid electrodes 51 for collecting photogenerated carriers from the semiconductor substrate 7 are provided side by side in the in-plane direction of the light receiving surface of the semiconductor substrate 7. A light receiving surface bus electrode 52 that is electrically connected to the light receiving surface grid electrode 51 and collects photogenerated carriers from the light receiving surface grid electrode 51 is arranged in the in-plane direction of the light receiving surface of the semiconductor substrate 7. Are provided so as to be substantially orthogonal to each other. The light-receiving surface grid electrode 51 and the light-receiving surface bus electrode 52 are electrically connected to the n-type impurity diffusion layer 2 at the bottom portions.

  On the other hand, the back surface aluminum electrode 61 formed by baking an electrode material containing aluminum (Al) and glass on the back surface (surface opposite to the light receiving surface) of the semiconductor substrate 7 except for a part of the outer edge region. It is provided throughout. Further, a back surface bus electrode 62 formed by firing an electrode material containing silver (Ag) and glass is provided so as to extend in substantially the same direction as the light receiving surface bus electrode 52. The back surface electrode 6 is constituted by the back surface aluminum electrode 61 and the back surface bus electrode 62.

  On the light receiving surface side of the semiconductor substrate 7, the amount of light incident on the semiconductor substrate 7 is reduced by the light reflection of the metal electrode, so that the light receiving surface electrode 5 needs to be processed into a thin line shape. On the other hand, on the back surface side of the semiconductor substrate 7, such light reflection of the metal electrode is not a problem, and the electrode shape is arbitrary. When these metal electrodes are formed in a thin line shape, printing methods, plating methods, etc. are used. Can also be used. Note that aluminum (Al) or silver (Ag) is often used as the material for the light-receiving surface electrode 5 and the back surface electrode 6, but is not particularly limited and may be appropriately selected from known materials. it can.

  Further, the lower region of the back surface aluminum electrode 61 in the surface layer portion on the back surface (surface opposite to the light receiving surface) side of the semiconductor substrate 7 contains p-type impurities at a higher concentration than the semiconductor substrate 1 and has a p-type conductivity type. A p + layer (BSF (Back Surface Field)) 4 having a higher conductivity than that of the semiconductor substrate 1 is formed. The p + layer (BSF) 4 provides an effect called BSF (Back Surface Field) that returns the light-generated minority carriers to the light incident surface side through the potential barrier.

  In the crystalline silicon solar battery 105 configured as described above, when sunlight L is irradiated onto the semiconductor substrate 7 from the light receiving surface side of the crystalline silicon solar battery 105, holes and electrons are generated. The generated electrons move toward the n-type impurity diffusion layer 2 by the electric field of the pn junction (the junction surface between the semiconductor substrate 1 made of p-type single crystal silicon and the n-type impurity diffusion layer 2), and the holes are formed in the semiconductor substrate. Move towards 1. As a result, the number of electrons in the n-type impurity diffusion layer 2 becomes excessive and the number of holes in the semiconductor substrate 1 becomes excessive. As a result, a photovoltaic force is generated. This photovoltaic power is generated in the direction of biasing the pn junction in the forward direction, the light-receiving surface electrode 5 connected to the n-type impurity diffusion layer 2 becomes a negative pole, and the back electrode 6 connected to the p + layer 4 becomes a positive pole. A current flows through an external circuit (not shown).

  In the present embodiment, the back surface side protective member 107 is disposed on the opposite side (back surface side) to the light receiving surface of the crystalline silicon solar cell 105 to protect the back surface side of the crystalline silicon solar cell 105. A resin back sheet is used as the back surface side protection member 107, and is a hydrolysis-resistant polyethylene terephthalate (PET) resin sheet, a polyvinyl fluoride (PVF) resin sheet, or the like, which is generally used in crystalline solar cell modules. A laminated resin sheet obtained by bonding together can be used. Moreover, what laminated | stacked oxide vapor deposition films, such as a silica and an alumina, on the surface of a resin sheet can also be used.

  Below, an example of the manufacturing method of the solar cell module 100 concerning Embodiment 1 comprised as mentioned above is demonstrated.

First, the several photovoltaic cell 105 is produced by a well-known method. For example, an inverted pyramid texture structure composed of minute irregularities (texture) is formed on the light-receiving surface side of the p-type single crystal silicon substrate by anisotropic etching using an alkaline aqueous solution. Next, the p-type single crystal silicon substrate is put into a thermal diffusion furnace and heated in the presence of phosphorus oxychloride (POCl ₃ ) vapor to form phosphorus glass on the surface of the p-type single crystal silicon substrate. Phosphorus is diffused into the single crystal silicon substrate, and an n-type impurity diffusion layer 2 is formed on the surface layer of the p-type single crystal silicon substrate. Thereby, the semiconductor substrate 7 having a pn junction is formed.

  Next, after removing the phosphorus glass layer of the p-type single crystal silicon substrate in a hydrofluoric acid solution, the silicon nitride film (SiN film) is formed as the antireflection film 3 by, for example, plasma enhanced chemical vapor deposition (PECVD). Is formed on the n-type impurity diffusion layer 2.

  Next, the electrode paste mixed with silver is printed on the light receiving surface of the semiconductor substrate 7 in a comb shape by screen printing, and the electrode paste mixed with aluminum is printed on the entire back surface of the semiconductor substrate 7 by screen printing. Thereafter, the electrode paste on the front and back surfaces of the semiconductor substrate 7 is baked to form the light receiving surface electrode 5 and the back surface electrode 6. As described above, the solar battery cell 105 shown in FIGS. 3-1 to 3-3 is manufactured.

  Next, the solar cells 105 produced as described above are electrically directly connected to form a string. The string is produced by electrically connecting a plurality of solar cells 105 produced as described above in series with the electrodes of the solar cells 105 through the connection wiring 21. At this time, the plurality of solar cells 105 are regularly arranged on substantially the same plane separated by a predetermined distance in a predetermined arrangement direction. As described above, a string in which the solar cells 105 as shown in FIG. 3-4 are electrically connected in series by the connection wiring 21 is produced.

  Next, the solar cell module 100 is produced using the string produced as described above. First, the solar cells 105 (strings) electrically connected and connected in series via the EVA resin layer 106 are installed on the back surface side protection member 107. Then, the EVA resin layer 104, the transparent resin film sheet 103, and the ionomer resin layer 102 are laminated in this order on the solar battery cell 105 (string), and the light-receiving surface side protective glass 101 is disposed thereon to form a laminate. Configure. Thereafter, these laminates are laminated by a laminate sealing process using a known vacuum heating laminator or autoclave to seal the solar battery cell 105 (string). Thereby, said each member is laminated and integrated, and the solar cell module 100 is obtained. Thereafter, a frame-shaped aluminum frame, which is a metal frame, is attached to the solar cell module 100.

  In the solar cell module 100 according to the first embodiment as described above, when a high voltage is applied between the internal wiring in the solar cell module 100 and the aluminum frame (metal frame) in a high-temperature and high-humidity state, PID The main leakage current paths that cause the phenomenon are: an aluminum frame (metal frame) having a ground potential, a light-receiving surface side protective glass 101, an ionomer resin layer 102, and a transparent resin film sheet 103 having an uneven surface, an EVA resin layer 104, A crystalline silicon solar battery cell 105 is formed.

  However, in this path, the ionomer resin layer 102 with high resistance and low water vapor transmission maintains a very high resistance as compared with the light-receiving surface side protective glass 101 and the EVA resin layer 104 even in an atmosphere of high temperature and high humidity. Is suppressed, Na + ions from the light-receiving surface side protective glass 101 are prevented from moving to the surface of the crystalline silicon solar battery cell 105, and the occurrence of the PID phenomenon can be prevented.

  The ionomer resin adheres well to glass, but it is difficult to adhere to a resin sheet such as PET. The ionomer resin adheres to the EVA resin, but tends to cause defects such as wrinkles, large undulations, residual bubbles, and a mixture layer at the interface.

  However, in the solar cell module 100 according to the first embodiment, the ionomer resin layer 102 and the EVA resin layer 104 are bonded to the transparent resin film sheet 103 having an uneven shape on the surface. For this reason, in the heating in the sealing process, the softened EVA resin layer 104 and the ionomer resin layer 102 flow to fill the irregularities on the surface of the transparent resin film sheet 103, so that the transparent resin film sheet 103, the EVA resin layer 104, and the transparent The resin film sheet 103 and the ionomer resin layer 102 are bonded. As a result, the adhesive strength between the ionomer resin layer 102 and the transparent resin film sheet 103 and the adhesive strength between the EVA resin layer 104 and the transparent resin film sheet 103 are improved, and as a whole, between the ionomer resin layer 102 and the EVA resin layer 104. This improves the adhesive strength.

  Moreover, in the solar cell module 100 according to the first embodiment, the uneven shape on the surface of the transparent resin film sheet 103 is different between different resins, that is, between the ionomer resin layer 102 and the transparent resin film sheet 103, and EVA resin. The difference in thermal expansion and contraction between the layer 104 and the transparent resin film sheet 103 can be alleviated, and generation of wrinkles and undulations and bubbles at the interface between different types of resins can be prevented.

  In other words, in the solar cell module 100 according to the first embodiment, the ionomer resin is obtained by inserting the transparent resin film sheet 103 having a moderately uneven surface between the ionomer resin layer 102 and the EVA resin layer 104. The adhesiveness at the interface between the layer 102 and the EVA resin layer 104 is enhanced, the formation of the mixture layer is prevented, and the uneven shape on the surface of the transparent resin film sheet 103 absorbs the difference in thermal expansion and contraction between the abutting resins. Therefore, it is possible to prevent wrinkles and large undulations and to perform laminate sealing without causing defects.

  Therefore, according to the first embodiment, it is possible to obtain a solar cell module that can prevent deterioration in characteristics due to the PID phenomenon in the solar cell system and can realize good laminate sealing.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to a following example, unless the meaning is exceeded.

Example 1
In Example 1, the solar cell module according to Embodiment 1 described above was manufactured. An ionomer resin in which a 3.2 mm thick white reinforced glass plate as the light-receiving surface side protective glass 101 and an 0.2 mm thick ethylene-methacrylic acid copolymer molecule as an ionomer resin layer 102 are intermolecularly bonded with Zn ions. Sheet, transparent PET resin film sheet with an average thickness of 75 μm as the transparent resin film sheet 103 having irregularities on the surface and an average surface roughness of 10 μm with a reference length of 0.25 mm on both sides, EVA resin layer 104 0.4 mm thick EVA resin sheet for solar cell, 156 mm square single crystal silicon solar cell having SiN _x passivation layer on the surface as crystalline silicon solar cell 105, 0 thickness as EVA resin layer 106 Hydrolysis resistance as a 4 mm solar cell EVA resin sheet and a back side protective member 107 Laminated ET resin backsheet, in this order, sealed and integrated by a known vacuum heat laminator.

  60 single-crystal silicon solar cells were electrically connected in series in advance, and power was output to the cable via the terminal box. The end face of the integrated laminate was supported by an aluminum frame to be protected.

In the production of a single crystal silicon solar cell, phosphorus is thermally diffused on the surface of a p-type single crystal silicon wafer by a known thermal diffusion method to form an n-type impurity diffusion layer, and a known plasma CVD is formed thereon. A passivation layer (antireflection layer) made of SiN _x was deposited by a thickness of about 75 nm by the method. Next, a grid electrode having a width of 100 μm was printed on the front surface of the p-type single crystal silicon wafer at a pitch of 2.2 mm by a silver paste screen printing method, and baked. Also, an aluminum paste was printed on the entire back surface of the p-type single crystal silicon wafer by screen printing, and thermal diffusion was performed to form a p + layer. Further, bus bar electrodes were printed on the front and back surfaces of the p-type single crystal silicon wafer by screen printing of silver paste, and baked.

  A plurality of single crystal silicon solar cells were electrically connected in series by soldering a solder-plated copper ribbon as the connection wiring 21 to the bus bar electrodes of the single crystal silicon solar cells.

  The following test was performed on the solar cell module thus manufactured to evaluate the characteristics.

(PID test)
The produced solar cell module was placed in an environmental testing machine under conditions of a temperature of 60 ° C. and a humidity of 85% RH with the light-receiving surface side protective glass facing upward. Then, water is spread on the light-receiving surface side protective glass, and a voltage of 1000 V is applied between the aluminum frame and the internal wiring of the solar cell module so that the internal wiring is in the negative direction from the external DC power supply and left for 96 hours. did. The output of the solar cell module in the standard state (natural atmosphere) after the test was measured and compared with the output of the solar cell module in the standard state (natural atmosphere) before the test.

  As a result, the measured output value of the solar cell module before and after the test hardly changed within a range of ± 0.5%, and the occurrence of the PID phenomenon was not recognized. From this, it was recognized that the solar cell module according to Embodiment 1 has an effect of preventing the PID phenomenon.

(Output test)
For comparison, the conventional solar cell module is similar to the solar cell module according to the first embodiment except that a transparent resin film sheet having irregularities on the surface is not provided between the ionomer resin and the EVA resin. Produced.

  FIG. 4 is a cross-sectional view of an essential part schematically showing a schematic configuration of a conventional solar cell module. In a conventional solar cell module, a light-receiving surface side protective glass 201, an ionomer resin 202, an EVA resin layer 204, a crystalline silicon solar cell 205, an EVA resin layer 206, and a back surface side protective member 207 are laminated in this order, and integrated by a laminating process. It has a structured structure. In the conventional solar cell module, there is a defect generation region 209 at the interface between the ionomer resin and the EVA resin, which is generated during the laminating process.

  The output of the solar cell module according to Embodiment 1 in the standard state (natural atmosphere) before the PID test showed a value of 103% of the initial output of the conventional solar cell module. In the conventional solar cell module, there are wrinkles and bubbles at the interface between the ionomer resin and the EVA resin, and the incident light is blocked and the output of the solar cell is reduced. On the other hand, in the solar cell module according to Embodiment 1, no defect occurred at the interface between the ionomer resin and the transparent resin film sheet and at the interface between the EVA resin and the transparent resin film sheet. For this reason, in the solar cell module concerning Embodiment 1, the fall of the output of the photovoltaic cell resulting from the defect of an interface was prevented, and it is thought that the favorable output was obtained.

(Adhesive strength test)
Furthermore, the light-receiving surface side protective glass of the solar cell module according to Embodiment 1 was fixed to a base, and a tensile metal fitting was firmly bonded to the back surface side protective member, and a tensile strength test based on JIS K6849 was performed. As a result, it was confirmed that the solar cell module according to Embodiment 1 did not peel off the adhesive surface even when a tensile strength of 20 N / cm ² was applied, and had sufficient adhesive strength as a solar cell module. When the film was further pulled with a strong force, it was peeled from the ionomer resin and the transparent resin film sheet at a tensile strength of 30 N / cm ² , and the adhesive strength was about 30 N / cm ² . Therefore, it can be said that the solar cell module according to Embodiment 1 sufficiently secures an adhesive strength of 20 N / cm ² or more, which is considered to be a practical adhesive strength in the module structure.

Embodiment 2. FIG.
In Embodiment 1, in the transparent resin film sheet 103 having unevenness on both surfaces, the surface in contact with the ionomer resin layer 102 and the surface in contact with the EVA resin layer 104 have the same surface roughness. The adhesive strength between the transparent resin such as PET and the EVA resin is larger than the adhesive strength between the transparent resin such as PET and the ionomer resin. For this reason, the surface roughness of the transparent resin film sheet 103 having irregularities on both surfaces can be increased on the surface in contact with the ionomer resin layer 102 and decreased on the surface in contact with the EVA resin layer 104.

  Therefore, in the crystalline silicon solar cell module according to Embodiment 2, the average surface roughness of the surface in contact with the ionomer resin layer 102 in the transparent resin film sheet 103 having irregularities on both surfaces is the average of the surface in contact with the EVA resin layer 104. Make it larger than the surface roughness. Moreover, the solar cell module concerning Embodiment 2 is the same structure as the solar cell module concerning Embodiment 1 except the average surface roughness of the surface in the transparent resin film sheet 103 which has an unevenness | corrugation in both surfaces.

  As shown in FIG. 2, the average surface roughness of the surface in contact with the ionomer resin layer 102 in the transparent resin film sheet 103 having irregularities on both surfaces is preferably in the range of 2 μm to 20 μm, and the surface in contact with the EVA resin layer 104 The average surface roughness Ra is made smaller than this. In addition, the lower limit of the average surface roughness Ra of the surface in contact with the EVA resin layer 104 is larger than that of the ionomer in terms of the adhesive strength with EVA, and can be adhered even on a smooth surface. If the opposite surface is uneven, the surface is naturally uneven, so that the surface in contact with the EVA resin preferably has some unevenness, and is about 0.5 μm.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to a following example, unless the meaning is exceeded.

(Example 2)
In Example 2, the solar cell module according to Embodiment 2 described above was produced. The solar cell module of Example 2 has an average surface roughness of 2 μm at a reference length of 0.25 mm on the surface in contact with the ionomer resin layer 102 in the transparent PET resin film sheet as the transparent resin film sheet 103 having irregularities on the surface. It was produced in the same manner as in Example 1 except that it was changed in the range of ˜20 μm.

  That is, five types of transparent PET resin sheets having an average surface roughness of 2 μm, 5 μm, 10 μm, 15 μm, and 20 μm at a reference length of 0.25 mm on the surface in contact with the ionomer resin layer 102 are prepared. Was made. Moreover, the average surface roughness of the surface in contact with the EVA resin layer 104 in the transparent PET resin film sheet was smaller than the average surface roughness of the surface in contact with the ionomer resin layer 102, and was 1 μm.

  The following test was performed on the solar cell module thus manufactured to evaluate the characteristics.

(PID test)
The five types of solar cell modules thus produced were placed in an environmental testing machine under conditions of a temperature of 60 ° C. and a humidity of 85% RH with the light-receiving surface side protective glass facing upward. Then, water is spread on the light-receiving surface side protective glass, and a voltage of 1000 V is applied between the aluminum frame and the internal wiring of the solar cell module so that the internal wiring is in the negative direction from the external DC power supply and left for 96 hours. did. The output of the solar cell module in the standard state (natural atmosphere) after the test was measured and compared with the output of the solar cell module in the standard state (natural atmosphere) before the test.

  As a result, the measured output value of the solar cell module before and after the test hardly changed within a range of ± 0.5%, and the occurrence of the PID phenomenon was not recognized. From this, it was recognized that the solar cell module according to Embodiment 2 has an effect of preventing the PID phenomenon.

(Output test)
Moreover, the solar cell of Example 1 using the transparent PET resin film sheet which made the surface roughness of both surfaces 10 m into the output in the standard state (natural atmosphere) before the PID test of five types of produced solar cell modules. Compared with the initial output of the module.

  As a result, the output in the standard state (natural atmosphere) before the PID test of the five types of solar cell modules is 99.3% to when the initial output of the solar cell module of Example 1 is 100.0%. A good value of 100.3% was shown.

(Adhesive strength test)
Furthermore, the light-receiving surface side protective glass of the five types of solar cell modules according to the second embodiment was fixed to the base, the tensile metal fitting was firmly bonded to the back surface side protective member, and the tensile strength test based on JIS K6849 was performed. . As a result, it was confirmed that the five types of solar cell modules according to the second embodiment did not peel off the adhesive surface even when a tensile strength of 20 N / cm ² was applied, and had sufficient adhesive strength as a solar cell module. . Was further pulled with a strong force, and detached from between the tensile strength ^24N / cm 2 ~ ionomer resin 30 N / cm ² and the transparent resin film sheet, the adhesive strength was about ^24N / cm ^{2 ~30N} / cm 2 .

Therefore, it can be said that the solar cell module according to Embodiment 2 sufficiently secures an adhesive strength of 20 N / cm ² or more, which is considered to be a practical adhesive strength in the module structure. That is, the average surface roughness at the reference length of 0.25 mm on the surface in contact with the ionomer resin layer of the transparent PET resin sheet is 2 μm to 20 μm, and the average surface roughness of the surface in contact with the EVA resin layer in the transparent PET resin film sheet Even if it is smaller than the average surface roughness of the surface in contact with the ionomer resin layer, it can be said that the adhesive strength of 20 N / cm ² or more, which is considered to be a practical adhesive strength in the module structure, is secured.

Embodiment 3 FIG.
FIG. 5: is principal part sectional drawing which shows typically schematic structure of the crystalline silicon solar cell module concerning Embodiment 3 of this invention. The crystalline silicon solar cell module according to Embodiment 3 is the same as that of Embodiment 1 except that the corona treatment modified layers 108 are provided on both surfaces of the transparent resin film sheet 103 having irregularities on both surfaces. It has the same structure as the battery module.

  In the solar cell module according to Embodiment 3 as described above, when a high voltage is applied between the internal wiring in the solar cell module and the aluminum frame (metal frame) in a high temperature and high humidity state, the PID phenomenon occurs. The main leakage current path is caused by the ground potential aluminum frame (metal frame), the light receiving surface side protective glass 101, the ionomer resin layer 102, the transparent resin film sheet 103 having unevenness on the surface, the EVA resin layer 104, and the crystalline silicon. The solar battery cell 105 is obtained.

  However, in this path, the ionomer resin layer 102 with high resistance and low water vapor transmission maintains a very high resistance as compared with the light-receiving surface side protective glass 101 and the EVA resin layer 104 even in an atmosphere of high temperature and high humidity. Is suppressed, Na + ions from the light-receiving surface side protective glass 101 are prevented from moving to the surface of the crystalline silicon solar battery cell 105, and the occurrence of the PID phenomenon can be prevented.

  In the solar cell module according to the third embodiment, the ionomer resin layer 102 and the EVA resin layer 104 are bonded to the transparent resin film sheet 103 having an uneven shape on the surface. For this reason, in the heating in the sealing process, the softened EVA resin layer 104 and the ionomer resin layer 102 flow to fill the irregularities on the surface of the transparent resin film sheet 103, so that the transparent resin film sheet 103, the EVA resin layer 104, and the transparent The resin film sheet 103 and the ionomer resin layer 102 are bonded. As a result, the adhesive strength between the ionomer resin layer 102 and the transparent resin film sheet 103 and the adhesive strength between the EVA resin layer 104 and the transparent resin film sheet 103 are improved, and as a whole, between the ionomer resin layer 102 and the EVA resin layer 104. This improves the adhesive strength.

  And since both surfaces of the transparent resin film sheet 103 having a concavo-convex shape are provided with a corona treatment modified layer 108 having excellent adhesion, the adhesive strength between the ionomer resin layer 102 and the transparent resin film sheet 103 and The adhesive strength between the EVA resin layer 104 and the transparent resin film sheet 103 is further improved, and the adhesive strength between the ionomer resin layer 102 and the EVA resin layer 104 is further improved as a whole. Therefore, even when the surface roughness of the irregularities on both surfaces of the transparent resin film sheet 103 is small, good laminate sealing can be realized. In addition, even when the corona treatment modified layer 108 is not necessarily formed on both surfaces of the transparent resin film sheet 103 having a concavo-convex shape on the surface, the above-described effect is obtained on the surface on which the corona treatment modified layer 108 is formed. can get. Further, the corona treatment modified layer 108 may be applied to the structure of the second embodiment.

  Further, in the solar cell module according to Embodiment 3, the uneven shape of the surface of the transparent resin film sheet 103 is different between resins, that is, between the ionomer resin layer 102 and the transparent resin film sheet 103, and the EVA resin layer. The difference in thermal expansion and contraction between the transparent resin film sheet 104 and the transparent resin film sheet 103 can be alleviated, and generation of wrinkles and undulations and bubbles at the interface between different types of resins can be prevented.

  That is, in the solar cell module 100 according to the third embodiment, the ionomer resin is obtained by inserting the transparent resin film sheet 103 having a moderately uneven surface between the ionomer resin layer 102 and the EVA resin layer 104. The adhesiveness at the interface between the layer 102 and the EVA resin layer 104 is enhanced, the formation of the mixture layer is prevented, and the uneven shape on the surface of the transparent resin film sheet 103 absorbs the difference in thermal expansion and contraction between the abutting resins. Therefore, it is possible to prevent wrinkles and large undulations and to perform laminate sealing without causing defects.

  Therefore, according to Embodiment 3, it is possible to obtain a solar cell module that can prevent deterioration in characteristics due to the PID phenomenon in the solar cell system and can realize better laminate sealing.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to a following example, unless the meaning is exceeded.

(Example 3)
In Example 3, the solar cell module according to Embodiment 3 described above was manufactured. In the solar cell module according to the third embodiment, as the transparent resin film sheet 103 having irregularities on the surface, the corona treatment in the atmosphere is performed on both surfaces of the transparent PET resin film sheet used in Example 1 immediately before lamination. This was prepared in the same manner as in Example 1 except that the above was applied.

  The following test was performed on the solar cell module thus manufactured to evaluate the characteristics.

(PID test)
The produced solar cell module was placed in an environmental testing machine under conditions of a temperature of 60 ° C. and a humidity of 85% RH with the light-receiving surface side protective glass facing upward. Then, water is spread on the light-receiving surface side protective glass, and a voltage of 1000 V is applied between the aluminum frame and the internal wiring of the solar cell module so that the internal wiring is in the negative direction from the external DC power supply and left for 96 hours. did. The output of the solar cell module in the standard state (natural atmosphere) after the test was measured and compared with the output of the solar cell module in the standard state (natural atmosphere) before the test.

  As a result, the measured output value of the solar cell module before and after the test hardly changed within a range of ± 0.5%, and the occurrence of the PID phenomenon was not recognized. From this, it was recognized that the solar cell module according to Embodiment 3 has an effect of preventing the PID phenomenon.

(Output test)
Further, for comparison, the solar cell according to the third embodiment described above, except that a transparent resin film sheet having irregularities on the surface and provided with a corona treatment modified layer is not provided between the ionomer resin and the EVA resin. A conventional solar cell module was fabricated in exactly the same manner as the module.

  The output of the solar cell module according to the third embodiment in the standard state (natural atmosphere) before the PID test showed a value of 99.5% of the initial output of the conventional solar cell module, which was almost the same. In the conventional solar cell module, there are wrinkles and bubbles at the interface between the ionomer resin and the EVA resin, and the incident light is blocked and the output of the solar cell is reduced. On the other hand, in the solar cell module according to Embodiment 3, no defects occurred at the interface between the ionomer resin and the transparent resin film sheet and at the interface between the EVA resin and the transparent resin film sheet.

(Adhesive strength test)
Furthermore, the light-receiving surface side protective glass of the solar cell module according to Embodiment 3 was fixed to a base, and a tensile metal fitting was firmly bonded to the back surface side protective member, and a tensile strength test based on JIS K6849 was performed. As a result, it was confirmed that the solar cell module according to Embodiment 3 did not peel off the adhesive surface even when a tensile strength of 20 N / cm ² was applied, and had sufficient adhesive strength as a solar cell module. When the film was further pulled with a strong force, it was peeled from the ionomer resin and the transparent resin film sheet at a tensile strength of 45 N / cm ² , and the adhesive strength was about 45 N / cm ² . That is, the solar cell module according to Embodiment 3 exhibited an adhesive strength value that was about 1.5 times that of the solar cell module of Example 1 that was produced without subjecting the transparent PET resin film sheet to corona treatment. Therefore, it can be said that the solar cell module according to Embodiment 3 sufficiently secures an adhesive strength of 20 N / cm ² or more, which is considered to be a practical adhesive strength in the module structure.

  As described above, the solar cell module according to the present invention is useful for preventing deterioration in characteristics due to the PID phenomenon in the solar cell system and realizing good laminate sealing.

  DESCRIPTION OF SYMBOLS 1 Semiconductor substrate, 2 n-type impurity diffusion layer, 3 Antireflection film, 4 p + layer (BSF (Back Surface Field)), 5 Light-receiving surface electrode, 6 Back electrode, 7 Semiconductor substrate, 21 Connection wiring, 51 Light-receiving surface grid electrode , 52 Light receiving surface bus electrode, 61 Back surface aluminum electrode, 62 Back surface bus electrode, 100 Crystalline silicon solar cell module (solar cell module), 101 Light receiving surface side protective glass, 102 Ionomer resin layer, 103 Transparent resin film sheet, 104 EVA resin Layer, 105 crystalline silicon solar cell (solar cell), 106 EVA resin layer, 107 back side protective member, 201 light receiving side protective glass, 202 ionomer resin, 204 EVA resin, 205 crystalline silicon solar cell, 206 EVA resin 207 Back side protection member 209 Defect occurrence Frequency, L sunlight.

Claims (8)

A photovoltaic cell using a crystalline semiconductor substrate having an insulating film formed on the surface of the light-receiving surface is placed between the light-receiving surface-side protective glass and the back-surface-side protective member so that the insulating film side is on the light-receiving surface-side protective glass side. A solar cell module sealed toward
Between the light receiving surface side protective glass and the solar battery cell, an ionomer resin layer from the light receiving surface side protective glass side, a transparent resin layer having irregularities on both surfaces, and an ethylene-vinyl acetate copolymer resin layer. Are stacked in this order,
A solar cell module characterized by. The arithmetic average roughness Ra at a reference length of 0.25 mm of the surface in contact with the ionomer resin layer in the transparent resin layer is in the range of 2 μm to 20 μm.
The solar cell module according to claim 1. The arithmetic average roughness Ra of the surface in contact with the ethylene-vinyl acetate copolymer resin layer in the transparent resin layer is smaller than the arithmetic average roughness Ra of the surface in contact with the ionomer resin layer in the transparent resin layer,
The solar cell module according to claim 2. Corona treatment is applied to the surface of at least one surface of the transparent resin layer,
The solar cell module according to any one of claims 1 to 3. A solar cell module manufacturing method for sealing solar cells using a crystalline semiconductor substrate having an insulating film formed on a light receiving surface side between a light receiving surface side protective glass and a back side protective member,
Between the light receiving surface side protective glass and the solar battery cell, an ionomer resin layer from the light receiving surface side protective glass side, a transparent resin layer having irregularities on both surfaces, and an ethylene-vinyl acetate copolymer resin layer. Laminate and seal in this order,
The manufacturing method of the solar cell module characterized by these. Arithmetic mean roughness Ra at a reference length of 0.25 mm of the surface in contact with the ionomer resin layer in the transparent resin layer is in a range of 2 μm to 20 μm,
The method for manufacturing a solar cell module according to claim 5. The arithmetic average roughness Ra of the surface in contact with the ethylene-vinyl acetate copolymer resin layer in the transparent resin layer is made smaller than the arithmetic average roughness Ra of the surface in contact with the ionomer resin layer in the transparent resin layer,
The method for manufacturing a solar cell module according to claim 6. Applying corona treatment to the surface of at least one surface of the transparent resin layer;
The manufacturing method of the solar cell module as described in any one of Claims 5-7 characterized by these.

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