JP2010027714A - Solar cell back sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a sheet, which has an end surface that prevents trouble such as short-circuiting due to exposure of metal at a sheet end when a metal foil for improving heat dissipation and barrier properties is used to constitute a back sheet used for a solar cell module, through a stable and efficient process. <P>SOLUTION: Disclosed is the method of manufacturing the solar cell back sheet which has a sealing plastic film on its both surfaces respectively, wherein a sheet formed by sticking a metal foil on one side of a plastic film as a base material is cut in a predetermined pattern, a plastic film is stuck allover both sides of the cut sheet respectively, and it is punched in a pattern different from the above predetermined pattern to provide an extending end face of the metal foil. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a solar cell sheet member, and more particularly to a solar cell backsheet used by being disposed on the back side of a solar cell module and a method for manufacturing the solar cell backsheet.

  Solar cells constitute the heart of a photovoltaic power generation system that directly converts solar energy into electricity, and are made of semiconductors. Further, the structure is generally unitized by packaging several to several tens of solar cell elements in series or in parallel and packaging for protecting the elements over a long period of time.

  A unit incorporated in this package is called a solar cell module. In general, a surface that is exposed to sunlight is covered with a front glass, and a gap is filled with a filler made of light-transmitting thermoplastic. The back surface is protected by a sheet (back sheet) made of heat resistant, moisture resistant, water resistant, weather resistant plastic material or the like.

  Since these solar cell modules are used outdoors, in their configuration, material structure, etc., sufficient heat resistance, weather resistance, water resistance, moisture resistance, wind pressure resistance, light resistance, rainfall resistance, chemical resistance, Moisture resistance, antifouling properties, light reflectivity, light diffusibility, and other properties are required.

  The solar cell module uses, for example, a crystalline silicon solar cell element or an amorphous silicon solar cell element, and a front glass layer, a filler layer, a solar cell element, a filler layer, and a back surface protection sheet (sheet) It is manufactured using a lamination method or the like in which layers such as a back layer are stacked in order and vacuum-sucked to perform thermocompression bonding.

  FIG. 1 shows a cross-sectional explanatory diagram of a configuration of an example of the general structure.

  In FIG. 1, a module is formed by laminating a front glass (surface protective sheet) 1, a filler 2, a solar cell element 3, and a back sheet 4 in this order from the light receiving side (surface), and leads between the solar cell elements. Electric power is taken out from a terminal 9 in a terminal box (junction box) 7 connected by a wire 5. In order to fix these constituent elements, an aluminum frame 8 surrounds the elastic sealing material 6.

  Among the components of this solar cell module, the backsheet is excellent in mechanical strength to protect the contents of the solar cell element and lead wires, etc., and has weather resistance, heat resistance, water resistance, light resistance, Excellent properties such as wind pressure resistance, yield resistance, chemical resistance, moisture resistance, antifouling property, etc., especially high moisture resistance to prevent intrusion of moisture, oxygen, etc., minimizing long-term performance degradation Therefore, there is a demand for high durability, low cost and safety.

  In order to realize these characteristics, the back sheet constituting the solar cell module has a wide range of plastic films or sheets taking advantage of its high insulating properties and easy secondary processing such as vapor deposition and coating. Various laminated sheets in which layers for improving performance are laminated in addition to a single-layer plastic sheet have been proposed.

  As an example of a laminated sheet, as disclosed in Patent Document 1, a protective sheet for a solar cell module in which a vapor-deposited thin film of an inorganic oxide is provided on one side of a fluorine-based resin sheet is backed. Proposed for use in sheets. For example, a laminate sheet having a configuration of polyvinyl fluoride (PVF) / polyethylene terephthalate (PET) / polyvinyl fluoride (PVF), which takes advantage of the high resistance of fluororesin, is representative. In addition, when using a versatile polyethylene terephthalate (PET) film, an inorganic oxide vapor deposition sheet of PET / PET provided with an inorganic oxide vapor deposition thin film layer in the middle of PET in order to enhance the content protection A laminated sheet having a configuration such as / PET is also used.

  Further, in order to further enhance the module resistance, a protective sheet for solar cell module in which an inorganic oxide vapor-deposited thin film is provided on one side of a fluorine resin sheet is used as a back surface protection sheet (back sheet). There has also been proposed an attempt to ensure the protection of contents and durability by using various properties such as adhesiveness, and in particular, improving the moisture resistance for preventing the invasion of moisture, oxygen and the like.

  Moreover, the solar cell backsheet characterized by consisting of a base film, a white ink layer, and an inorganic vapor deposition film is proposed for the purpose of raising the power generation efficiency of a solar cell (patent document 2). Here, incident light is reflected by the white ink layer to increase the power generation efficiency of the solar cell. At the same time, another effect of the white ink layer is that the incident light is not absorbed and reflected by the back sheet surface. The temperature rise is prevented, and deterioration of the elements and the like is suppressed.

  As a characteristic affected by the temperature rise of the solar battery module, it is known that the power generation efficiency of the solar battery cell is reduced in addition to the lifetime. In particular, it is known that when a crystalline silicon solar cell element is used, the power generation efficiency is reduced with a rise in temperature inside the module, leading to a reduction in output.

  Many countermeasures including the above-mentioned document have been proposed to make up for the drawbacks caused by the lack of barrier properties and heat transfer by using a plastic sheet for the back sheet of a solar cell.

  In particular, a conventional configuration in which a metal foil such as an aluminum foil having a high thermal conductivity and an excellent barrier property is used as a constituent element of the back sheet has been reviewed in order to solve these problems.

  Conventionally, as a solar cell back sheet, a heat-resistant, moisture-resistant, water-resistant, weather-resistant plastic, such as a polyvinyl fluoride film, and a metal foil, in particular, a laminated structure in which an aluminum foil is sandwiched, is often used. It was.

  One of the reasons for using metal foil for solar cell backsheets is that it has excellent content protection, especially water vapor and oxygen barrier properties, and at the same time dissipates heat generated inside the module due to high thermal conductivity. It is also possible to expect an effect.

  However, in the above method, there is a risk of electrical contact with other parts such as lead wires and junction boxes by using conductive metal foil.

  Several proposals have been made to solve this problem.

  For example, in Patent Document 3, as a back surface protection sheet for solar cells, in order to prevent contact with lead wires and electrodes due to melting at the time of module molding, a heat-resistant, weather-resistant plastic film made of a polyester resin with a high melt viscosity, A back surface protection sheet for solar cells has been proposed in which metal foils are sandwiched from both sides.

Even if it is possible to prevent contact between the metal foil and other members such as lead wires due to deformation that may occur during module molding in this way, ensuring barrier properties such as water vapor and dissipating heat inside the module In the conventional method using the metal foil to achieve the same, if the end of the metal foil remains exposed, the problem of contact with other parts such as lead wires and junction boxes still remains. .

  This problem is more serious not only for conventional solar cells but also for thin solar cells that are expected to be developed in the future.

  Currently, a general solar cell is called a crystal system, and as a module, as shown in the above figure, photovoltaic elements (solar cell elements) of thin crystalline silicon of about 100 mm square are arranged in series. It is. Since each solar cell element is connected by wiring in a crystalline solar cell, the electricity generated can be taken out by connecting the wiring to a junction box.

  However, a thin film solar cell is formed by applying silicon, metal compounds, organic compound dyes, etc. to a substrate by a method such as coating or vapor deposition. In order to take out the generated electricity, it is placed on the entire back side of the power generation layer. This is done by using a metal film. Due to such a structure, if the metal foil is exposed on the end face of the thin-film solar battery backsheet, the metal film for electrical extraction and the metal foil are in contact with each other, and there is a risk of short circuit or electric leakage.

  Furthermore, silicon, metal compounds, organic compound dyes, etc., which are constituent elements of photovoltaic elements of thin film solar cells, are extremely susceptible to water vapor, so that they are made up of only vapor-deposited films based on plastic films. In the sheet, the barrier property is insufficient, and it is essential that a metal foil such as an aluminum foil having a very high barrier property is included.

  As one method for preventing the metal foil from being exposed from the end surface of the back sheet, the edge of the punched pattern using an insulating tape or the like after punching the metal foil with the plastic film bonded to both sides has been performed so far. The method of sealing the part is performed. Also, after pasting a plastic film and a sheet metal foil slightly smaller than the punching pattern prepared in advance, the plastic film is punched out slightly wider from the peripheral edge of the metal foil, and there is no end exposure. A method of creating a backsheet is also considered.

  Hereinafter, a typical example of the end exposure of the metal foil and conventional measures will be described with reference to the drawings.

  FIG. 3 is an explanatory view of a cross section of a solar battery backsheet having a relatively simple structure in which a plastic film is bonded to both surfaces of a metal foil. The laminated body is bonded to the periphery 14 of the junction box arrangement region 16. The top view at the time of punching with the pattern of the back seat outer edge part 15 (FIG. 3-1) and sectional drawing (FIG. 3-2) in the ab line | wire are shown.

  If a sheet having a metal foil and a plastic film laminated on the entire surface is punched out, for example, there is a risk that a junction box or a lead wire easily contacts the cut end surface 14 of the metal foil 18 at a portion 16 where the lead wire passes through the back sheet. is there. Similarly, the cut end face 15 at the outer edge of the metal foil 18 may easily come into contact with a nearby electrode or the like to cause a short circuit.

  One conventional method for preventing this is to punch out a sheet having a metal foil and a plastic film laminated on the entire surface, and then use an insulating tape or the like on the end surface exposed portions 14 and 15 of the metal foil 18 to end edges of the punched pattern. It is the method of sealing a part.

However, end sealing by this method does not increase the processing speed, the processing cost is high, and the equipment is limited, resulting in a very expensive processing method. These problems are particularly noticeable when the metal foil to be sealed has a long and complicated shape including the outer edge of the backsheet.

As described above, in the prior art, the content protection function required for the solar battery back sheet, typically, moisture resistance or the like to prevent corrosion of cells and wiring that cause a decrease in the output of the solar battery. In addition to having weather resistance that can withstand long-term outdoor use, there is still a problem in that a back sheet that secures necessary electrical insulation is manufactured in a stable and efficient process.
JP 2000-188212 A JP 2006-210557 A JP 2002-134770 A

  When using a metal foil to improve the heat dissipation and barrier properties of the backsheet used in the solar cell module, it has an end face that can prevent failures such as a short circuit due to metal exposure at the edge of the sheet. It is a problem to manufacture a sheet by a stable and efficient process.

  The invention of claim 1 of the present invention is a solar cell backsheet used for protecting the back surface of a solar cell module, in which at least a plastic film is laminated on both surfaces of the metal foil, and an end surface of the intermediate layer metal foil extends. It is a solar cell backsheet characterized by being sealed with a double-sided plastic film.

  In the invention of claim 2 of the present invention, a sheet in which a metal foil is bonded to one side of a plastic film serving as a substrate is cut into a predetermined pattern, and the plastic film is further bonded to the entire front and back surfaces of the cut sheet. The method for producing a solar cell backsheet according to claim 1, wherein the pattern is punched into a pattern different from the pattern.

  The invention according to claim 3 of the present invention is characterized in that, when the metal foil is bonded to one side of the plastic film, the width of the plastic film is wider than the width of the metal foil. It is a manufacturing method.

  The invention according to claim 4 of the present invention is such that when a plastic film is bonded to the entire front and back surfaces of the cut sheet cut into a predetermined pattern, the plastic film has a continuous winding shape and the width is the width of the cut sheet. It is wider than this, It is a manufacturing method of the solar cell backsheet of Claim 2 or 3.

  According to the invention of claim 5 of the present invention, the plastic film is further bonded to the entire front and back surfaces of the cut sheet rather than a predetermined pattern for cutting the sheet having the metal foil bonded to one side of the plastic film as the base material. The method for producing a solar cell backsheet according to any one of claims 2 to 4, wherein the pattern to be punched is narrower than the edge of the metal foil is not exposed after punching.

  Invention of Claim 6 of this invention is a manufacturing method of the solar cell backsheet of any one of Claim 2 to 5 characterized by metal foil being aluminum foil.

The solar cell backsheet of the present invention is a solar cell backsheet used for protecting the back surface of a solar cell module, in which at least a plastic film is laminated on both surfaces of a metal foil, and an end surface of the intermediate layer metal foil is extended. Because it is sealed with plastic film on both sides, it is a metal foil that is a feature that protects the contents, especially gas barrier and heat dissipation related to water vapor and oxygen gas, etc., and metal that comes from using metal foil It is possible to provide a back sheet that prevents harmful effects caused by exposure to light.

  Furthermore, the present invention is different from the above pattern after cutting a sheet in which a metal foil is bonded to one side of a plastic film as a base material into a predetermined pattern, and bonding the plastic film to the entire front and back surfaces of the cutting sheet. Because it is a method for manufacturing a solar battery back sheet that is punched into a pattern, after punching out a sheet laminated with a metal foil and a plastic film on the entire surface, an insulating tape or the like is used to expose the end surface of the metal foil. Compared with the conventional method of sealing the part, it is possible to provide a method for efficiently producing a back sheet in a stable process, which prevents the adverse effects caused by the exposure of the metal resulting from the use of the metal foil.

  In the method of the present invention, in the bonding of the metal foil to one side of the plastic film as the base material, the width of the plastic film is wider than the width of the metal foil, so that the both ends when the bonding is continuously performed By preventing the film from coming off and preventing the occurrence of defects in the next process, the metal foil is used to protect the contents, especially the gas barrier properties related to water vapor, oxygen gas, etc., and heat dissipation, and the metal foil is used. Thus, it is possible to provide a method for efficiently producing a backsheet solar cell backsheet that prevents the adverse effects caused by the exposure of the metal, compared to the conventional method, in a stable process.

  Further, in the present invention, when the plastic film is bonded to the entire front and back surfaces of the cut sheet cut into a predetermined pattern, the plastic film has a continuous winding shape and the width is wider than the width of the cut sheet. Prevents the film from being removed at both ends when continuous bonding is performed, and prevents the occurrence of defects in the next process, thereby protecting the contents, which is a feature of using metal foil, particularly a gas barrier related to water vapor, oxygen gas, etc. To provide a method for efficiently producing a solar cell back sheet that is superior in terms of heat resistance and heat dissipation and that prevents the adverse effects of metal exposure resulting from the use of metal foil in a stable process compared to conventional methods. I can do it.

  In the method of the present invention, a pattern in which a plastic film is bonded to the entire front and back surfaces of the cut sheet and then punched out more than a predetermined pattern in which a sheet having a metal foil bonded to one side of a plastic film as a base material is cut. However, it is so narrow that the end of the metal foil is not exposed after punching, so that a solar battery back sheet in which the end of the metal foil is sealed with a plastic film with the front and back extended in a continuous process is manufactured. Can provide a way to

  In this invention, the solar cell back sheet excellent in the content protection property, workability, and cost property can be manufactured by using metal foil as aluminum foil.

  As above. According to the method of the present invention, at least a plastic film is laminated on both surfaces of a metal foil, which is a solar cell backsheet used for protecting the back surface of a solar cell module, and an end surface of the intermediate layer metal foil is extended. Because it is sealed with a plastic film on both sides, the metal foil is used to protect the contents, especially the gas barrier properties related to water vapor and oxygen gas, heat dissipation, and the use of metal foil. It is possible to provide a back sheet that prevents harmful effects caused by exposure.

  Furthermore, it is possible to provide a method for efficiently producing a back sheet having such features in a stable process.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a simplified illustration of the solar cell backsheet of the present invention. FIG. 2-1 is a plan view of the solar battery backsheet of the present invention, and FIG. 2-2 is a cross-sectional view of the cut surface along the line AB.

  The invention of claim 1 is a laminate sheet used for protecting the back surface of a solar cell module, in which at least a plastic film is laminated on both sides of a metal foil, and the both sides of the end face of the metal foil of the intermediate layer are extended. A solar cell backsheet characterized by being sealed with a plastic film.

  Such a solar battery back sheet has a metal sheet end face sealed with a plastic sheet both around the hole opened at the location where the junction box, lead wire, etc. are disposed, and at all locations on the outer edge of the sheet. It also has excellent performance that can be used safely in terms of electrical insulation.

  However, the solar battery backsheet having such a configuration has excellent performance as described above, but the end face of the metal foil is exposed after punching out a sheet in which the metal foil and the plastic film are laminated. The conventional manufacturing method in which the end of the punched pattern is sealed using an insulating tape or the like in the portion has room for improvement in terms of a stable and efficient process.

  As a result of intensive studies on a method for stably and efficiently producing the solar cell backsheet shown in claim 1, the present inventors continuously attached a metal foil on one surface of a plastic film as a base material. The combined sheet is cut into a predetermined pattern, a plastic film is continuously bonded to the entire front and back surfaces of the cut sheet, and further punched into a pattern different from the above pattern. The method has been completed.

  An embodiment of the present invention related to claims 2 to 6 will be described below with reference to the drawings.

  FIG. 2 is a plan view (FIG. 2-1) and a simplified sectional view (FIG. 2-2) of the solar cell backsheet of the present invention described above.

6 to 8 are simplified explanatory views of the method for producing the solar battery back sheet of the present invention. FIG. 6 is a diagram of a plastic film and a metal by cutting after bonding a plastic film and a metal foil as a base material. FIG. 8 is a plan view and a simplified cross-sectional view showing the state after removing unnecessary portions of the foil to form a sheet, and FIG. 8 shows the state after the plastic film is bonded to both the front and back surfaces of the cut sheet. The state after punching in FIG. 8 is substituted in FIG. In these drawings, the adhesive layer is not shown for simplification of explanation.
(1) In the method of the present invention, first, a plastic film as a substrate and a metal foil are bonded together.

  As a plastic film used in the present invention, a polyester substrate selected from polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polycyclohexanedimethanol-terephthalate (PCT), a polycarbonate-based substrate, Alternatively, it can be selected from acrylic base materials. Other polyolefin-based resins, polyamide-based resins, polyarylate-based resins, and the like can be appropriately selected in consideration of heat resistance, strength properties, electrical insulation properties, and the like. In particular, a fluorine-based resin film is awarded when importance is attached to resistance such as weather resistance.

Fluorine resin films include polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), polyethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), tetrafluoroethylene par A fluoroalkyl vinyl ether copolymer (PFA), a tetrafluoroethylene-hexafluoropropylene copolymer (FEP), or a film or sheet of an acrylic modified product of these fluororesins can be appropriately selected.

  The plastic film used for the solar cell backsheet of the present invention is preferably a PVF film or a PET film. Further, the number average molecular weight is in the range of 18,000 to 40,000, the cyclic oligomer content is 1.5% by weight or less, and the intrinsic viscosity is 0.00. A polyester film having a hydrolysis resistance of 5 dl / g or more is desirable.

  The plastic film used in the method of the present invention can be appropriately selected from the above candidates such as PET film and PVF film. Moreover, the activated surface treatment of the plastic film surface for ensuring the adhesive force between the plastic film and the metal foil can also be performed by a known method such as corona discharge treatment.

  The thickness of the plastic film can be set as appropriate, but from the viewpoint of processability, dimensional stability, and price, PVF film is 25 μm to 50 μm, and in the case of PET film, especially from the viewpoint of processability, depending on the adhesive in the bonding process In order to prevent roll contamination, a thickness of 150 μm or more is preferable, and a thickness of 300 μm or less is preferable.

  In addition, the plastic film may be a simple substance, but a plastic film that has been subjected to treatment such as vapor deposition of inorganic oxide or lamination for the purpose of improving physical properties such as barrier properties and adhesion can also be used. The example of the laminated body at the time of laminating | stacking was shown by sectional explanatory drawing in FIG.4 and FIG.5.

  FIG. 4 shows a cross section in the case of a layer structure of PET film 17 / adhesive layer 22 / aluminum foil 18 / adhesive layer 20 / PET film 19 as a laminate. This configuration is a relatively simple configuration using an inexpensive PET film and is suitable when special performance is not required.

  In FIG. 5, the cross section in the case of the layer structure of PVF film 23 / adhesive layer 22 / aluminum foil 18 / adhesive layer 20 / PET film 19 / adhesive layer 24 / PVF film 25 is shown as a laminate. This configuration is disadvantageous in price compared to the configuration of FIG. 4, but is suitable when special performance such as an application requiring weather resistance is required by using a PVF film. The layer structure of the laminate that can be used in the present invention is not limited to this.

  The metal foil used in the method of the present invention can be appropriately selected from the above candidates such as aluminum foil. Moreover, the activated surface treatment of the metal foil for securing the adhesive force between the plastic film and the metal foil can be performed by a known method corresponding to the type of the foil. This method is a known treatment method such as an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method.

  The metal foil is typically an aluminum foil or a copper foil from the viewpoint of heat dissipation and gas barrier properties, but an aluminum foil is preferred from the viewpoint of cost and workability. In the case of an aluminum foil, the thickness is preferably in the range of 10 μm to 50 μm. If the thickness is 10 μm or less, defects such as pinholes that hinder barrier properties are likely to occur, and the thickness does not need to exceed 50 μm.

The method for laminating the metal foil and the plastic film is not particularly limited, such as a dry laminating method, an extruder method, or a thermal laminating method, but the dry laminating method is preferably used from the viewpoint of heat resistance. The adhesive used for the adhesive layer is such that the adhesive strength between the plastic film substrate and the metal foil does not deteriorate due to long-term outdoor use, and that the adhesive does not turn yellow. Is required, and urethane adhesives can be used.

  The resin that forms this adhesive layer is polyester, polyether, polyurethane, polyether urethane, polyester urethane, isocyanate, polyolefin, polyethyleneimine, cyanoacrylate, organic titanium compound, epoxy. Examples thereof include resins used as known adhesives for dry lamination, which are made of a resin, an imide resin, a silicone resin, a modified product thereof, or a mixture thereof.

  Moreover, a silane coupling agent can be appropriately mixed with the resin forming the adhesive layer. Examples of the silane coupling agent used for this include epoxy-based organosilane compounds such as 3-glycidoxypropyltrimethoxysilane and amine-based organosilanes such as [3- (2-aminoethyl) aminopropyl] trimethoxysilane. And an isocyanato-based organosilane compound such as 3-isocyanatopropyltriethoxysilane.

  In FIG. 6, the winding of the base plastic film having the width indicated by 12 in the width direction and the winding of the metal foil having the width indicated by 15 in the width direction are bonded by, for example, a dry laminating method. The state of the subsequent laminated sheet is shown, and the end portion indicated by 12 can be a position to be an end portion as a product of the solar battery back sheet. If it does in this way, since the edge part cutting | disconnection of the width direction in a subsequent cutting and punching process becomes unnecessary, it becomes easy to perform the registration in a cutting and punching process. In this case, the width of the metal foil is usually 10 mm to 15 mm inside at the end than the width of the base plastic film.

By laminating in this step, a continuous laminated sheet after laminating the base plastic film and the metal foil as shown in FIG. 6-2 can be wound.
(2) The second step of the method of the present invention is to cut the laminated sheet of the base plastic film and the metal foil into a predetermined pattern to obtain a sheet.

  The surface of the metal foil bonded in the bonding process may interfere with the application of the adhesive layer in the next process due to contamination due to contact with a roll or the like, contamination from the environment, or oxidation. Therefore, if necessary, a known activated surface treatment is performed on the surface of the metal foil before printing.

  The cutting pattern of the laminated sheet is a pattern in which the end of the metal foil is not exposed when punched in the post-process, that is, in a wider range than the pattern that becomes the end of the product punched in the post-process.

For example, the cutting range 14 shown in the plan view of FIG. 7-1 is a pattern that is wider than the pattern 13 punched in the post-process shown in FIG. 2-1, and is thus punched in the post-process. The end of the subsequent metal foil is surely sealed by the end of the plastic film. Thus, the laminated sheet after cutting shown in FIG. 7 is completed as a sheet.
(3) The third step of the method of the present invention is to bond a plastic film to the entire front and back surfaces of the cut laminated sheet.

  FIG. 8 shows a state after a plastic film is bonded to the entire surface of the laminate shown in FIG. As shown in Fig. 8-1, in the flow direction of the plastic film (vertical direction in the figure), the cutting sheets are arranged with a certain gap between the cutting sheets. The end of the metal foil is sealed with a plastic film that is securely extended. Here, the constant gap is a dimension determined from the design of the product. Generally, there are many 20 mm to 30 mm. In this case, by applying an adhesive to the entire surface of the continuous plastic film, the plastic film and the plastic film and the metal foil can be bonded together including the gap portion of the cut sheet, and the metal foil end face can be sealed. There will be no leakage.

  Here, the plastic film to be bonded can be appropriately selected from the above candidates. Generally, a polyethylene terephthalate film having a thickness of 50 μm to 150 μm or a polyvinyl fluoride film having a thickness of 25 μm to 50 μm is frequently used.

The activated surface treatment and the laminating method of the plastic film can be performed by well-known methods as described, and the adhesive in the case of dry lamination can be appropriately selected from the above candidates.
(4) The fourth step of the method of the present invention is to create a solar battery back sheet by punching a pattern from a laminate having a plastic film bonded to the entire surface to remove unnecessary portions.

  From the sheet of FIG. 7, for example, a punched sheet including a hole in the junction box and surrounding trimming is created to create a back sheet.

  As a pattern, for example, in the case of FIG. 2, the outer side is a 12 pattern in FIG. 2 and the inner side is a 13 pattern. It is discarded and the solar cell back sheet shown in FIG. 2 is completed.

  Hereinafter, specific examples of the present invention will be described.

<Example 1>
A polyurethane film manufactured by Mitsui Chemicals Polyurethanes Co., Ltd. with a solid content of 30% by weight on one side of a polyethylene terephthalate (PET) resin film 17 having a thickness of 150 μm produced by an extrusion method as a plastic film as a base material. The adhesive (main agent Takelac A515 / curing agent Takenate A50 = 10/1 solution) was applied so that the application amount in a dry state was 4.0 g / m ² . An aluminum foil 18 having a thickness of 25 μm is laminated thereon as a metal foil, and then cut into a pattern as shown in FIGS. A leaf laminate was obtained.

Further, a polyurethane adhesive (base agent Takelac A515 / curing agent Takenate A50 = 10/1 solution) manufactured by Mitsui Chemicals Polyurethane Co., Ltd. having a solid content of 30% by weight is applied to one side of the aluminum foil side of the laminate by a dry laminating machine. A polyethylene terephthalate (PET) resin film 19 having a thickness of 50 μm, which is manufactured by an extrusion method, is applied as a plastic film by applying the coating amount in a dry state to 4.0 g / m ² , It punched out like 13 and created the solar cell backsheet of this invention.

  Thereby, the solar cell back sheet | seat provided with the end surface which can prevent troubles, such as a short circuit by exposure of the metal of a sheet | seat edge part, was able to be manufactured in the stable and efficient process.

<Example 2>
A polyurethane film manufactured by Mitsui Chemicals Polyurethanes Co., Ltd. having a solid content of 30% by weight on one side of a polyethylene terephthalate (PET) resin film 19 having a thickness of 150 μm produced by an extrusion method as a plastic film as a base material. The adhesive (main agent Takelac A515 / curing agent Takenate A50 = 10/1 solution) was applied so that the application amount in a dry state was 4.0 g / m ² . An aluminum foil 18 having a thickness of 25 μm is laminated thereon as a metal foil, and then cut into a pattern as shown in FIGS. A leaf laminate was obtained.

Further, a polyurethane adhesive (base agent Takelac A515 / curing agent Takenate A50 = 10/1 solution) manufactured by Mitsui Chemicals Polyurethane Co., Ltd. having a solid content of 30% by weight is applied to one side of the aluminum foil side of the laminate by a dry laminating machine. It is applied so that the coating amount in a dry state is 4.0 g / m ^2, and a 25 μm-thick polyvinyl fluoride (PVF) resin film 23 is bonded as a plastic film. Using a dry laminating machine on one side of a 25 μm polyvinyl fluoride (PVF) resin film 25, a polyurethane adhesive (main agent Takelac A515 / curing agent Takenate A50 = 10/1 solution with a solid content of 30% by weight) ) the coating weight in the dry state is then coated to a 4.0 g / m ² It was stuck to the side of the PET film of the serial laminate. The laminated body was registered and punched out in a pattern such as 12 or 13 to produce a solar cell backsheet of the present invention.

  Thereby, the solar cell back sheet | seat excellent in the weather resistance provided with the end surface which can prevent troubles, such as a short circuit by exposure of the metal of the sheet | seat edge part, was able to be manufactured in the stable and efficient process.

Cross-sectional explanatory diagram of an example of a solar cell module BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2-1 is a plan view FIG. 2-2 is a simplified cross-sectional view along the line AB FIG. 3-1 is a plan view and FIG. 3-2 is a simplified cross-sectional view taken along line ab. Simplified explanatory diagram of solar cell backsheet layer configuration example of the present invention Simplified explanatory diagram of solar cell backsheet layer configuration example of the present invention Simplified explanatory diagram of solar cell backsheet of the present invention (1. After bonding of base material and metal foil) Fig. 6-1 is a plan view Fig. 6-2 is a simplified cross-sectional view along line AB Simplified explanatory view of solar cell backsheet of the present invention (2. After cutting) FIG. 7-1 is a plan view and FIG. FIG. 8-1 is a plan view and FIG. 8-2 is a simplified cross-sectional view taken along the line A-B.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Front glass 2 ... Filler 3 ... Solar cell element 4 ... Back sheet 5 ... Lead wire 6 ... Sealing agent 7 ... Junction box 8 ... Aluminum frame 9 ... Terminal 10 ... Back sheet 12 ... Plastic film outer edge part 13 ... Plastic film Inner edge 14 ... Metal foil inner edge 15 ... Metal foil outer edge 16 ... Junction box position 17 ... Base plastic film (PET)
18 ... Metal foil 19 ... PET film 20 ... Adhesive layer 22 ... Adhesive layer 23 ... PVF film 24 ... Adhesive layer 25 ... PVF film

Claims (6)

  A solar battery back sheet used for protecting the back surface of a solar cell module, in which at least a plastic film is laminated on both sides of the metal foil, and sealed by a double-sided plastic film in which end faces of the intermediate layer metal foil are extended. A solar battery back sheet characterized by comprising:   A sheet in which a metal foil is bonded to one side of a plastic film to be a base material is cut into a predetermined pattern, and the plastic film is bonded to the entire front and back surfaces of the cut sheet, and then punched into a pattern different from the above pattern. The manufacturing method of the solar cell backsheet of Claim 1.   The method for producing a solar cell backsheet according to claim 2, wherein the width of the plastic film is wider than the width of the metal foil when the metal foil is bonded to one side of the plastic film.   When the plastic film is bonded to the entire front and back surfaces of the cutting sheet cut into a predetermined pattern, the plastic film is in a continuous winding shape, and the width thereof is wider than the width of the cutting sheet. The manufacturing method of the solar cell backsheet of 2 or 3.   Rather than a predetermined pattern for cutting a sheet with a metal film bonded to one side of a plastic film as a base material, a pattern in which a plastic film is bonded to the entire front and back surfaces of the cut sheet and then punched out is a metal foil after punching. The method for manufacturing a solar cell backsheet according to any one of claims 2 to 4, wherein the end portion is narrow enough not to be exposed.   The method for producing a solar cell backsheet according to any one of claims 2 to 5, wherein the metal foil is an aluminum foil.

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