WO2005106969A1 - Solar cell module manufacturing method and solar cell module - Google Patents

Abstract

In a method of manufacturing a solar cell module wherein a solar cell is sealed with a resin between a light receiving side transparent board and a rear board, a laminate body (60) is manufactured by arranging a plurality of the solar cells between the light receiving side transparent board and the rear board, and the laminate body (60) is put in a sealing process container (61) composed of a gas impermeable flexible sheet. A plurality of the sealing process containers (61) containing the laminate bodies (60) are introduced into an oven (63) and are arranged in parallel at intervals. Inside the sealing process container (61) is depressurized to exhaust the air between the light receiving side transparent board and the rear board. The laminate body (60) is heated to melt the sealing resin by permitting a hot blast to flow parallel to the laminate body (60) in the oven (63), then the laminate body is cooled to solidify the sealing resin. Thus, the solar cell modules having various shapes and sizes can be manufactured by the simple operation at a low cost.

Description

 Specification

 Method of manufacturing solar cell module and solar cell module

 Technical field

 The present invention relates to a method for manufacturing a solar cell module and a solar cell module. In particular, the present invention relates to a method for manufacturing a solar cell module in which solar cells are sealed with resin between a light-receiving-surface-side transparent plate and a back plate.

 Background art

 [0002] In recent years, awareness of environmental protection has increased, and solar power generation has become even more important. Solar cells are sandwiched between protective materials and sealed with transparent resin, and used outdoors as solar cell modules. As a transparent resin for encapsulation, ethylene-vinyl acetate copolymer (hereinafter sometimes abbreviated as EVA) resin or the like is used, which is placed between the protective material and the solar cell. It is sealed by being sandwiched, heated and melted, and then solidified. In order to arrange and wire the solar cells efficiently, it is preferable to seal a plurality of solar cells in one solar cell module.

 [0003] As a method of sealing a plurality of solar cells in a solar cell module, a method using a double vacuum chamber type laminator and a method using a single vacuum chamber type laminator are mainly known. ing. The double vacuum chamber type laminator is capable of independently controlling the degree of vacuum in the two chambers separated by a gas-impermeable flexible sheet. The structure is complicated. On the other hand, a single vacuum type laminator tends to cause bubbles to remain and cell cracks, but the structure of the laminator is simple. These laminators are used depending on the specifications of the solar cell module. In many cases, in any of the above-mentioned laminators, the laminate is placed on a plate having a built-in heater, and the laminate is heated and sealed while evacuating the space where the laminate exists.

Japanese Patent Application Laid-Open No. 61-69179 (Patent Document 1) discloses a double-vacuum solar cell panel laminate in which solar cells are laminated between a power bar glass and a back surface material via a filler. Degassed by a method, and applied to a method of manufacturing a solar cell panel that has a bonding process by heating and pressing. A method of manufacturing a solar cell panel using EVA as a filler and maintaining a double vacuum chamber in a specific temperature range for a specific time is described. By bonding under specific temperature conditions, EVA can be crosslinked without foaming or yellowing. Under the conditions described in the examples, the pressure was reduced to 0.3 Torr (approximately 0.0004 MPa), and then calo-heat was started. When the temperature of the substrate surface on the heater side reached 140 ° C., vacuum compression was performed. After the cross-linking reaction at ° C, the pressure was cooled to 50 ° C or less, and the vacuum pressure bonding was released. The double-vacuum laminator used in the examples of this publication places the laminate on a hot plate and heats it.

 [0005] JP-A-59-22978 (Patent Document 2) discloses a filling adhesive for a solar cell module containing an ethylene-based copolymer and an organic peroxide and having embossed patterns on both surfaces thereof. The sheet is described. It is said that the adhesive sheet has an embossed pattern so that blocking of the sheet can be prevented, the degassing property in the modularizing process is excellent, and bubbles are hardly generated. The example of the publication describes a laminating method in which the temperature is raised to 150 ° C. in a vacuum laminator while the pressure is reduced, the pressure is reduced at 150 ° C. for 1 hour, the glass is cooled, and the pressure is stopped. ing. The laminator used in the examples of this publication is a vacuum laminator separated into two chambers by silicone rubber.

[0006] Japanese Patent Application Laid-Open No. 9-36405 (Patent Document 3) discloses that a photovoltaic element is formed as a laminate between a front surface member and a back surface member with an encapsulant resin interposed therebetween. It describes a solar cell module that is held at a vacuum degree of 5Τππ or less for 5 to 40 minutes, heat-pressed at a vacuum degree of 5 Torr or less, cooled and bonded after the heat-press bonding. It is described that a module that is hardly peeled off from the surface member and hardly generates bubbles is provided by thermocompression bonding under such conditions. According to the method described in the publication, generation of residual air bubbles can be suppressed even when a simple vacuum chamber type laminator having a simple structure is used. The single-vacuum laminator used in the embodiment of the publication has a laminated body serving as a module placed on a plate in which a heater is embedded, and a silicone rubber sheet is placed thereon, and the exhaust force of the plate is also reduced. It can be evacuated with a vacuum pump. It also describes that the problem of remaining air bubbles can be improved by inserting a non-woven fabric between the solar cell and the sealing resin and letting the air in the laminate escape through the voids in the non-woven fabric. The

 [0007] By the way, the installation location of a solar cell has recently become diversified, and it has been used not only on the roof of a building but also on a wall. When used on a wall, the solar cell module is used not only for mounting on the outer wall but also for the wall itself. In this case, the appearance of the building will be greatly affected, so it is important to have a regular and free solar cell module with no defects. At the same time, there is a need for large-area solar cell modules that have sufficient strength as building structures. Moreover, there is a need for solar cell modules of various shapes and sizes corresponding to the design of each building. In recent years, the use of bent glass for the exterior walls of buildings has been increasing in response to the variety of designs required for buildings. Therefore, it is desired to enclose solar cells between curved substrates. However, solar cells were easily damaged and difficult to encapsulate between curved substrates. Furthermore, in recent years, the method of building the glass wall of a building by the DPG (Dot Point Glazing) method has been widely adopted.In this case, it is necessary to insert a bracket into the hole formed in the glass. Become. In the case of manufacturing such various solar cell modules, it is difficult to seal with a laminator having the above-described structure.

[0008] Furthermore, when a large number of cells are connected, sandwiched between two plates and sealed by heating and compression, it has been difficult to avoid damage to the solar cells. In particular, when the number of cells was large and the area of the entire module was large, it was unavoidable that some of the cells were subjected to a large load unevenly or an excessive load soon. In a module, many cells are connected in series with each other, so that if one cell is damaged, a series of connected cells will not function. If the cell is damaged, it will not only impair the appearance, but also greatly reduce the power generation performance, and must be discarded as a defective product. Accordingly, a sealing method that makes the cell less likely to be damaged is also desired.

[0009] Utility model registration No. 2500974 (Patent Document 4) discloses a laminated structure in which two plate-like members are joined via an adhesive sheet such that a solar cell is sandwiched between two adhesive sheets. In the body, a laminate is described in which a sheet piece having substantially the same thickness as the solar cell is sandwiched in a gap formed between the adhesive sheets outside the solar cell. With such a configuration, Thus, the thickness of the peripheral portion of the laminate can be made uniform, and the external force is less likely to penetrate moisture and the like into the gap, so that separation can be prevented. It is described that EVA is used as an adhesive sheet, and a glass sheet is used as a plate-like body on both sides.

 [0010] Japanese Patent Application Laid-Open No. 2003-110127 (Patent Document 5) discloses a solar cell module in which a plurality of solar cells are arranged between a front cover and a back cover and sealed with a transparent filler such as EVA. Describes a solar cell module in which a translucent spacer (setting block) is arranged between solar cells. It is described that it is optimal to use a spacer having the same material as the transparent filler and the same thickness as the solar cell as the spacer. It is said that this spacer can secure an air flow path that is not deformed by the weight of the cover alone. It is described that this allows a solar cell module having no air to remain therein.

 [0011] Japanese Patent Application Laid-Open No. 2001-7376 (Patent Document 6) describes a solar cell module in which solar cell is sealed with resin between curved glass plates. Here, a transparent acrylic resin anaerobic adhesive is used as the sealing resin, and a spacer is arranged at the peripheral portion between the two substrates, and the liquid adhesive is injected. And harden. In this way, by curing the solar cell without applying a load to the solar cell, it was possible to enclose the cell between curved glass plates. However, it is not always easy to enclose the liquid adhesive, and it is also difficult to arrange the arrangement of a plurality of solar cells. However, it does not necessarily mean that the resin obtained by curing has a satisfactory performance such as adhesiveness and durability.

[0012] Japanese Patent Application Laid-Open No. 9-92867 (Patent Document 7) discloses a method in which a filling sheet made of EVA resin is placed on both sides of a solar battery cell, and the layers are joined by heating under vacuum and preliminarily. It describes a method for manufacturing a solar cell module, in which a formed sheet is formed, and then the preformed sheet is placed on a curved glass and heated and joined by vacuum. In the embodiment of this publication, when performing vacuum heating, the preformed sheet and the curved glass are inserted into a rubber bag, set in a heating chamber, and heated while vacuuming the rubber bag with a vacuum pump. The method is described. By adopting such a method, bonding to curved glass is also possible. The joining operation twice is complicated, Is not applicable to a configuration in which is covered with curved glass.

 [0013] Therefore, it is possible to seal a solar cell between curved substrates, or to seal a solar cell module having metal fittings, and to manufacture solar cell modules of various shapes and dimensions. There is a demand for a sealing method that can be performed. At the same time, it is possible to seal the solar cell at a low cost with a simple operation that does not easily damage the cell, to arrange the solar cells in a regular manner, and to obtain a solar cell module with excellent adhesion and durability. A sealing method that can be used is also desired.

Patent Document 1: JP-A-61-69179

 Patent Document 2: JP-A-59-22978

 Patent Document 3: Japanese Patent Application Laid-Open No. 9-36405

 Patent Document 4: Utility Model Registration No. 2500974

 Patent Document 5: JP-A-2003-110127

 Patent Document 6: Japanese Patent Application Laid-Open No. 2001-7376

 Patent Document 7: Japanese Patent Application Laid-Open No. 9-92867

 Disclosure of the invention

 Problems to be solved by the invention

[0015] The present invention has been made to solve such a problem, and relates to a method for manufacturing a solar cell module in which solar cells are sealed with resin, in various shapes and sizes. It is an object of the present invention to provide a method for manufacturing a solar cell module which can seal a solar cell module by a simple operation and at a low cost with a simple operation. It is another object of the present invention to provide a solar cell module having a module fixing bracket.

 Means for solving the problem

[0016] The object is to provide a method for manufacturing a solar cell module in which a solar cell is sealed with resin between a light-receiving-surface-side transparent plate and a back plate.

A first sealing resin sheet covering substantially the entire surface of the transparent plate on the light-receiving surface is disposed between the transparent plate on the light-receiving surface and the solar cell, and the rear plate is substantially disposed between the rear plate and the solar cell. A second sealing resin sheet covering the entire surface is arranged to produce a laminate, The laminate is placed in a sealing treatment container made of a gas-impermeable flexible sheet, and a plurality of sealing treatment containers containing the laminate are introduced into an oven and arranged in parallel at intervals. And

 The inside of the sealing processing container is decompressed to discharge air between the light-receiving surface side transparent plate and the back plate, and the laminate is heated by flowing hot air in the oven in a direction parallel to the laminate. To melt the sealing resin,

 The problem is solved by providing a method for manufacturing a solar cell module, which solidifies the sealing resin by successively cooling.

 [0017] By using a plurality of sealing treatment containers made of a gas-impermeable flexible sheet, laminated bodies of various shapes can be accommodated therein. Further, by simultaneously heating a plurality of sealing processing containers in an oven, it is possible to perform the sealing operation with simple operation and low cost. At this time, heat can be efficiently and uniformly transmitted by arranging the sealing treatment containers in parallel in the oven at an interval from each other and flowing hot air in a direction parallel to the laminate. is there.

At this time, it is preferable that the sealing treatment container is a bag made of a gas-impermeable flexible sheet. It is also preferable to cover the outer edge of the laminate with a breathable cloth and then put the laminate in a sealed container. It is a preferred embodiment to heat the laminate while maintaining the inside of the oven at substantially atmospheric pressure. It is preferable that a plurality of solar cells are arranged at intervals and connected to each other by a conductor, and at this time, a plurality of sets in which a plurality of solar cells are connected to each other in a serial direction by a conductor are arranged at intervals. It is also a preferred embodiment to form the laminate by arranging the laminate in parallel with each other and to heat the oven so that the air flow in the oven is parallel to the serial direction. It is also preferable that the oven has a hot air inlet and a hot air outlet provided on the opposite side. The sealing container is connected to a vacuum pump via a pipe, and a set of a pressure gauge and a valve is provided for each of the plurality of pipes, and the set is connected to a sealing processing container in which a leak is detected by the pressure gauge. It is also preferred that the closed valve is closed. It is also preferable that each of the sealing processing containers is connected to a vacuum pump via a pipe, and a tank is provided between the sealing processing container and the vacuum pump. At this time, a pressure gauge for measuring the pressure in the tank and outside air are introduced into the tank. It is preferable to have a valve and to finely adjust the pressure in the tank. It is also preferable to provide at least one temperature control chamber adjacent to the oven and perform a preheating operation or a cooling operation in the temperature control chamber.

 [0019] In the above method, in the laminate, a sealing resin sheet piece thicker than the thickness of the solar cell may be disposed in a gap between the solar cells or in a margin outside the solar cell. It is suitable. In a preferred embodiment, both the light receiving surface side transparent plate and the back plate are glass plates. It is also a preferred embodiment that at least one of the light-receiving-surface-side transparent plate and the back plate is curved. It is also a preferred embodiment that the laminate has a light-receiving-surface-side transparent plate or a member protruding outward on the back surface. At this time, it is preferable that the member protruding outward is a metal fitting for fixing the module. It is also preferable that the sealing resin is made of a resin selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl butyral and polyurethane.

 [0020] In a preferred embodiment, a step of heating the sealing resin while maintaining the pressure in the sealing processing container at 0.05 MPa or more (step 1), when sealing in the sealing processing container, Step of depressurizing the inside of the sealing container at a temperature lower than the melting point of the resin to 0. OlMPa or less (Step 2), and step of raising the temperature to a temperature equal to or higher than the melting point of the sealing resin while maintaining the reduced pressure 3) A sealing operation including a step of increasing the pressure in the sealing container (Step 4) and a step of cooling (Step 6) is performed. In another preferred embodiment, the sealing resin sheet is made of a crosslinkable thermoplastic resin, and is sealed at a temperature lower than the melting point of the sealing resin when sealing in a sealing treatment container. Depressurizing the inside of the processing vessel to a pressure of not more than 0.1 OlMPa (step 2), raising the temperature to a temperature equal to or higher than the melting point of the sealing resin while maintaining the reduced pressure (step 3), Perform a sealing operation that increases the pressure of each step (step 4), the step of raising the temperature to the temperature range where the crosslinking reaction proceeds (step 5), and the step of cooling (step 6). .

[0021] The object described above is a solar cell module having a sealing resin layer between a light-receiving-surface-side transparent plate and a back plate, and a solar cell sealed in the sealing resin layer. A metal fitting for fixing the module, the metal fitting is inserted into a through hole formed in one of the transparent plate on the light-receiving surface side and the back plate, and the end on the head side of the metal fitting is formed on the sealing resin layer side. Located on the opposite side of the bracket The problem is solved by providing a solar cell module characterized in that the side end protrudes outward. At this time, it is preferable that a spacer is not provided on the peripheral edge of the sealing resin layer. It is also preferable that the through hole is a countersink, and the head of the metal fitting is fitted into the countersink.

 The invention's effect

 According to the method for manufacturing a solar cell module of the present invention, a method for manufacturing a solar cell module in which solar cells are sealed with resin is provided. Can be sealed with simple operation and low cost.

 Brief Description of Drawings

FIG. 1 is a schematic cross-sectional view of an example of a solar cell module after a sealing operation.

 FIG. 2 is a schematic cross-sectional view of an example of a laminate before a sealing operation.

 FIG. 3 is a schematic cross-sectional view of another example of a laminate before a sealing operation.

 FIG. 4 is a schematic cross-sectional view of another example of a laminate before a sealing operation.

 FIG. 5 is an enlarged schematic cross-sectional view of a laminate before a sealing operation in the example of FIG. 2 is started.

 FIG. 6 is an enlarged schematic cross-sectional view of a laminate during heating and heating in the example of FIG. 2.

 FIG. 7 is an enlarged schematic cross-sectional view of a laminate after a sealing operation in the example of FIG. 2.

 FIG. 8 is a schematic view of an example of a sealing apparatus.

 FIG. 9 is a schematic diagram showing a case where heating is performed so that an air flow in an oven is in a direction parallel to a series direction of solar cells.

 FIG. 10 is a schematic diagram showing a case where heating is performed so that an airflow in an oven is in a direction perpendicular to a series direction of solar cells.

 FIG. 11 is a view (No. 1) showing a procedure of a laminating step in Examples 1 and 2.

 FIG. 12 is a view (No. 2) showing a procedure of a laminating step in Examples 1 and 2.

 FIG. 13 is a view (No. 3) showing a procedure of a laminating step in Examples 1 and 2.

 FIG. 14 is a diagram showing temperature and pressure during a sealing process in Examples 1 and 2.

 Explanation of symbols

[0024] 1 Solar cell module

2 Transparent plate on light-receiving side 3 Back plate

 4 Solar cells

 5 Fat

 8 conductor

 9 Clearance

 10 Margin

 20 1st sealing resin sheet

 30 2nd sealing resin sheet

 40-48 Sealing resin sheet piece

 53 Module mounting bracket

 60 laminate

 61 Sealed container

 63 oven

 66 tank

 67 vacuum pump

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an example of a solar cell module after a sealing operation. 2 to 4 are schematic cross-sectional views of an example of the laminate before the sealing operation. FIG. 5 is an enlarged schematic cross-sectional view of the laminated body before the start of the sealing operation in the example of FIG. FIG. 6 is an enlarged schematic cross-sectional view of the laminate during heating and heating in the example of FIG. FIG. 7 is an enlarged schematic cross-sectional view of the laminate after the sealing operation in the example of FIG. FIG. 8 is a schematic diagram of an example of the sealing apparatus. FIG. 9 is a schematic diagram showing a case where heating is performed so that the airflow in the oven is in a direction parallel to the direction in which the solar cells are arranged in parallel. FIG. 10 is a schematic diagram showing a case where heating is performed so that the airflow in the oven is in a direction perpendicular to the series direction of the solar cells.

The solar cell module 1 obtained by the manufacturing method of the present invention is one in which a solar cell 4 is sealed with a resin 5 between a light-receiving-side transparent plate 2 and a back plate 3. The number of the solar cells 4 sealed in the solar cell module 1 may be one, but usually, The number of solar cells 4 is sealed. Usually, the light receiving surface 6 and the back surface 7 of the adjacent solar cell 4 are connected via the conducting wire 8. Figure 1 shows a schematic cross-sectional view of that case.

As the solar cell 4 used in the present invention, various solar cells such as a single-crystal silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, and a compound semiconductor solar cell can be used. . These solar cells are generally thin plates having a thickness of 1 mm or less, more generally 0.5 mm or less, and are often rectangular with a side of 5 cm or more. As a material of the substrate, a semiconductor substrate such as silicon or germanium, a glass substrate, a metal substrate, or the like can be used, but a silicon substrate is most important practically. In the case of a silicon substrate, a thin plate is desired in terms of cost requirements, but since it is a hard and brittle material, it is necessary to take care to seal the substrate particularly easily at the time of sealing.

 [0028] The number of solar cells 4 sealed in one solar cell module 1 is not particularly limited, and may be only one. In that case, only the wiring to the outside of the solar cell is connected. As the number of solar cells 4 sealed in one solar cell module 1 increases, the overall dimensions of solar cell module 1 increase. Since large-sized solar cell modules 1 are often custom-made in various shapes or dimensions, there is a great benefit in adopting the manufacturing method of the present invention. Therefore, it is preferable that 10 or more, preferably 30 or more solar cells 4 are arranged in one solar cell module 1. In addition, when a large number of solar cells 4 are sealed, air bubbles are likely to be generated, and when the solar cells 4 move during the sealing operation, a problem in appearance tends to occur. Also, as the number of solar cells 4 sealed in one solar cell module 1 increases, the defective product rate due to damage to the solar cells 4 increases, so it is necessary to carefully seal It is.

[0029] The width of the gap 9 between the adjacent solar cells 4 is not particularly limited, but is usually 0.5 mm or more, and when it is less than 0.5 mm, the adjacent solar cells 4 come into contact with each other to be sealed. In such a case, the cell may be damaged. If priority is given to daylighting, it is preferable to make the gap 9 wide. If priority is given to light use efficiency, it is preferable to make the gap 9 narrow. It is adjusted appropriately according to the requirements of the application and design. [0030] The plurality of solar cells 4 are arranged via a predetermined width, and are connected to each other by a conductive wire 8. At this time, the adjacent solar cells 4 are connected to each other by the conducting wire 8 between the light receiving surface 6 and the back surface 7, and a large number of solar cells 4 are connected in series. The connection between the light receiving surface 6 or the back surface 7 and the conductive wire 8 is performed using a conductive adhesive such as solder. Further, in order to efficiently collect the generated current, it is preferable to form a current collecting pattern on the light receiving surface 6 with a conductive paste or the like so as to conduct the current collecting pattern with the conductor 8. Furthermore, there are also cases where non-adjacent cells or conductors 8 located at distant positions are connected to each other, or a hole is made in the back plate 3 to lead the conductor 8 out.

 [0031] The conducting wire 8 is also called an interconnector. The material is not particularly limited, and a copper wire or the like is used. It is preferable to use a thin ribbon-shaped conductor 8 because it is sandwiched between the light receiving surface side transparent plate 2 and the back plate 3, and the thickness thereof is usually 0.5 mm or less, and preferably 0.5 mm or less. 3 mm or less. It is usually 0.05 mm or more. It is preferable that the conductive wire 8 be coated with a conductive adhesive such as solder in advance, since the connection work becomes easy. In the state where the conductor 8 is connected, the surface force of the photovoltaic cell 4 The height of the conductor 8 up to the highest part is a force that varies from place to place. In some cases, it is about 5mm thicker.

 The material of the light-receiving-surface-side transparent plate 2 may be, for example, polycarbonate resin, acrylic resin, or the like, in addition to glass, as long as it is transparent to sunlight. It is preferable to use glass in consideration of durability, hardness, flame retardancy, and the like while pressing. A glass plate having a surface compressive stress of 20 MPa or more is preferable because a structural material having a large area is often formed. In addition, if the area is large, thermal cracks are likely to occur due to temperature rise due to sunshine or the like. Therefore, it is preferable to use a glass plate having a surface compressive stress of 20 MPa or more also from this point. However, since a glass sheet having a large surface compressive stress is usually manufactured by heating and rapidly cooling a float sheet glass, occurrence of a certain strain is inevitable. Due to the warpage of the glass caused by this, an excessive load is applied to some of the solar cells 4 at the time of sealing, and there is a great need to pay attention to cell breakage.

Here, the surface compressive stress of the sheet glass is a value measured according to JIS R3222. Specific examples of a glass sheet having a surface compression stress of 20 MPa or more include double-strength glass and tempered glass. Lath, ultra-tempered glass and the like. Double-strength glass usually has a surface compressive stress of 20 to 60 MPa, tempered glass has a surface compressive stress of usually 90 to 130 MPa, and ultra-tempered glass has a surface compressive stress of usually 180 to 250 MPa. . As the surface compressive stress increases, the strength increases, but the warpage tends to increase and the manufacturing cost tends to increase. Further, double strength glass is preferable in that a glass with relatively small warpage is manufactured or when the glass breaks immediately, the glass does not fall into small pieces. The glass plate is selected according to the application and purpose.

 As the back plate 3, a plate similar to the light-receiving surface-side transparent plate 2 is preferably used. In addition, if the weight of the module is important, a thin and flexible material such as a plastic film can be used. The back plate 3 does not necessarily have to be transparent, but it is better for the back plate 3 to be transparent to sunlight if lighting is taken into consideration. Further, for the same reason as the light-receiving-surface-side transparent plate 2, it is preferable to use glass, particularly a glass plate having a surface compressive stress of 20 MPa or more.

[0035] The material of the glass is not particularly limited, and among the powers in which soda-lime glass is preferably used, a high transmission glass (so-called white plate glass) is preferably used for the light-receiving surface side transparent plate 2. High transmission glass is soda lime glass with a low iron content and high light transmittance. For the glass of the back plate 3, besides using the above-mentioned high transmission glass or soda lime glass (so-called blue plate glass) having a relatively high content of iron, heat ray reflection glass, heat ray absorption glass, etc. may be used. Is also preferable depending on the application. Further, a template glass having an embossed pattern formed on the surface may be used. The thickness of the glass plate is not particularly limited, but is preferably 3 mm or more, more preferably 5 mm or more, when used as a structural material. Care must be taken when using such a thick glass plate because the cell may be damaged when the glass plate is overlaid on the cell before bonding because the influence of its own weight is large. The thickness of the glass plate is usually 20 mm or less. Further, when the area of the glass is equal to or more than the force lm ² adjusted according to the application, there is a great benefit to adopt the manufacturing method of the present invention.

[0036] The light-receiving-surface-side transparent plate 2 and the back plate 3 used in the present invention may be flat or curved. At least one of the light-receiving side transparent plate and the back plate In the case where the gap is curved, it is difficult to use a laminator, which has been widely used in the past, for sealing, and therefore, there is a great advantage in employing the manufacturing method of the present invention. Solar cell

The portion other than 4 may be greatly curved, but usually, in a region where the solar cell 4 is present, a region having a curvature radius of 500 to 10,000 mm is preferable. If the radius of curvature is less than 500 mm, it may be difficult to seal while preventing cell cracking, and it is preferably 700 mm or more. On the other hand, when the radius of curvature exceeds 10,000 mm, the difficulty in sealing using the curved light-receiving surface-side transparent plate 2 is reduced, and the necessity of employing the present invention may be reduced. The radius of curvature is preferably 5,000 mm or less, more preferably 2,000 mm or less. Here, the shape of the light-receiving-surface-side transparent plate 2 may be a part of a cylinder or a part of a sphere. In addition, in the case where the curvature may change depending on the place or the direction, the radius of curvature in the present invention refers to the minimum radius of curvature in the region where the solar battery cell 4 exists.

 [0037] The light-receiving-surface-side transparent plate 2 and the back plate 3 used in the present invention may have holes. For example, in recent years, the method of building the glass wall of a building by the DPG (Dot Point Glazing) method has been widely adopted.In this case, it is necessary to insert a fitting into the hole provided in the glass, The light-receiving surface side transparent plate 2 having the holes and the back plate 3 are used for sealing. At this time, the sealing may be performed in a state where the metal fitting is attached to the hole.In such a case, the advantage of adopting the manufacturing method of the present invention using the sealing processing container 61 made of a flexible sheet is particularly advantageous. large.

[0038] The material of resin 5 is not particularly limited as long as it is transparent and has adhesiveness and flexibility, but ethylene-butyl acetate copolymer (EVA), polybutyral, and polyurethane are also used. A type of resin whose group strength is also selected is preferably used. At this time, the crosslinked resin is preferable in terms of strength and durability. Therefore, it is preferable that the raw material of the resin 5 is a crosslinkable thermoplastic resin, particularly a resin whose crosslinking reaction proceeds when heated. Such resin is sandwiched between the transparent plate 2 on the light-receiving surface side and the back plate 3 in the form of a sheet, heated and melted, and then a crosslinking reaction is allowed to proceed if necessary, and then cooled and solidified to form a solar cell. Seal 4 By using a material which is crosslinked by heating, it is possible to obtain a material having excellent durability and adhesiveness. As a crosslinkable thermoplastic resin The type of resin selected from the group consisting of ethylene-butyl acetate copolymer (EVA), polyvinyl butyral, and polyurethane is preferably used, as long as the crosslinking reaction proceeds when heated. For example, in the case of EVA, crosslinking can be carried out by mixing and heating a crosslinking agent, and in the case of polyurethane, crosslinking can be carried out by reacting an isocyanate group with a hydroxyl group.

In the case of polyurethane, since the crosslinking reaction proceeds at a relatively low temperature, it is suitable when, for example, a resin plate having low heat resistance is used for at least one of the transparent plate on the light-receiving surface side and the back plate. In addition, polyurethane is excellent in flexibility, so peeling will occur even when a combination of materials with significantly different coefficients of thermal expansion, such as glass and plastic, is used for the transparent plate on the light-receiving side and the back plate. << It is suitable. Furthermore, polyurethane has excellent penetration strength.

 [0040] Among the crosslinkable thermoplastic resins, it is preferable to use a thermoplastic resin containing a crosslinking agent. The thermoplastic resin at this time is not particularly limited as long as the crosslinking reaction proceeds when heated together with the crosslinking agent, but the ethylene-vinyl acetate copolymer (excellent in transparency, flexibility, durability, etc.) EVA) is most preferably used.

 The sealing resin sheet is sandwiched between the transparent plate 2 on the light-receiving surface side and the back plate 3, and is heated and melted and then cooled and solidified to seal the solar cell 4. In this case, it is preferable that the sealing resin sheet contains a cross-linking agent in the EVA resin, in which case the cross-linking reaction proceeds after heating and melting, followed by cooling to seal with the cross-linked EVA. Can be stopped. The EVA in the sealed resin sheet should have a melting point of 50 to 80 ° C. as measured by the DSC method. The viewpoint of the balance between transparency and shape retention is also preferable.

 [0042] It is preferable that the sealing resin sheet has an appropriate embossing on one or both sides, because blocking can be prevented and bubbles remaining can be easily suppressed. The preferred emboss depth is 10 to 100 m, and if it is too deep, air bubbles may remain on the contrary. The thickness of the sheet is preferably 0.2 to 2 mm, more preferably 0.3 to 1 mm, and one or a plurality of the sheets may be stacked and adjusted for use.

 Hereinafter, a sealing operation method according to the production method of the present invention will be described.

First, the example of FIG. 2 will be described. The example in Fig. 2 shows the flat transparent plate 2 on the light-receiving surface side and the back surface. This is an example in which a sealing resin sheet piece thicker than the thickness of the solar cell 4 is arranged in both the gap 9 between the solar cells 4 and the margin 10 outside the solar cell 4 using the plate 3. . FIG. 2 is a schematic cross-sectional view of an example of the stacked body 60 before the sealing operation, and shows a cross section cut in parallel to a direction in which a plurality of solar cells 4 are connected in series.

 First, the second sealing resin sheet 30 is overlaid on the back plate 3 so as to cover substantially the entire surface. In the example of FIG. 2, the operation of superimposing the force on the back plate 3 is performed. However, the transparent plate 2 on the light receiving surface side may be first placed on the lower surface, and then may be laminated in the reverse order.

 [0046] The thickness of the second sealing resin sheet 30 is preferably 0.5 mm or more, more preferably 1 mm or more. Also, it is usually 5 mm or less, preferably 3 mm or less. By setting the thickness to a certain value or more, the solar cell 4 can be effectively protected. The second sealing resin sheet 30 is preferably configured by laminating a plurality of sealing resin sheets. This is because it becomes easy to adjust the thickness of the second sealing resin sheet 30 according to the application and required performance. In the example of FIG. 2, three sealing resin sheets 31, 32, and 33 are stacked to form a second sealing resin sheet 30. The second encapsulating resin sheet 30 may be partially omitted as long as it covers a substantially entire surface of the back plate 3, for example, to arrange conductive wires. It may be composed of a plurality of sealed resin sheets.

 [0047] The solar cell 4 is placed on the second sealing resin sheet 30. At this time, the plurality of solar cells 4 connected to each other in the above-described manner are placed, and if necessary, are arranged in the same length and width. In this case, the solar cell 4 connected in advance may be placed, the connection may be made on the first sealing resin sheet 20, or the partially connected one may be placed and the force remains. May be connected.

 Subsequently, in the margin 10 outside the solar cell 4, the sealing resin disposed substantially continuously over the entire periphery of the margin 10 on the second sealing resin sheet 30. A sheet piece 40 and a sealing resin sheet piece 41 that is overlapped with the sheet piece 40 and arranged at an interval from each other are arranged. In addition, sealing resin sheet pieces 42 and 43 are arranged in gaps 9 between solar cells 4.

In the margin 10 outside the solar cell 4 or the gap 9 between the solar cells 4, the sealing resin sheet pieces 40, 41 or the sealing whose total thickness is larger than the thickness of the solar cell 4大 By arranging the resin sheet pieces 42 and 43, when the inside is decompressed, the atmospheric pressure from both sides The sealing resin sheet pieces 40, 41 or the sealing resin sheet pieces 42, 43, which do not directly apply a load to the solar cell 4, receive the load. Therefore, it is possible to prevent the load of the light-receiving-surface-side transparent plate 2 from being directly applied to the solar battery cells 4 arranged in the module, and to prevent cell cracking in the decompression step. In particular, according to the manufacturing method of the present invention, a vertical load of the laminated body 60 receives a load derived from the atmospheric pressure during the sealing operation, and thus such a configuration is preferable. The larger the number of solar cells 4 sealed in one solar cell module 1, the higher the percentage of defective products resulting from damage to the solar cells 4, so the sealing resin sheet pieces 40, 41, 42 The benefits of placing 43 are great. Here, the total thickness refers to the total thickness of the overlapping portions when a plurality of sealing resin sheet pieces are used in an overlapping manner.

[0050] The total thickness force of the sealing resin sheet pieces is preferably thicker than the total value of the thickness of the solar cell 4 and the thickness of the conductive wire 8, and preferably 0.2 mm or more than the total value. More preferred. Further, it is preferable that the total thickness of the sealing resin sheet pieces is 0.3 mm or more than the thickness of the solar cell 4, and it is more preferable that the thickness is 0.6 mm or more. Specifically, it is preferable that the total thickness of the sealing resin sheet pieces is 0.5 to 5 mm. The total thickness of the sealing resin sheet pieces is more preferably 0.8 mm or more, and even more preferably 1 mm or more. If the thickness is too thin, cell cracking may occur during the sealing operation. On the other hand, the total thickness of the sealing resin sheet pieces is more preferably 3 mm or less, and more preferably 2 mm or less. If the thickness is too large, air bubbles are likely to remain around the solar cell 4.

 [0051] It is preferable that the sealing resin sheet pieces 40, 41, 42, and 43 are arranged at intervals in the horizontal direction so that the internal air can be discharged therefrom. By securing a passage for actively discharging the internal air, the remaining air bubbles can be suppressed, and the solar cell module 1 having a good appearance can be manufactured. At this time, if the sealing resin sheet pieces are directly overlapped with each other, at least one of the sealing resin sheet pieces is horizontally spaced between the resin sheet pieces, and the internal air is discharged therefrom. It is good if it can be discharged.

In the example of FIG. 2, in the margin 10 outside the solar cell 4, it is disposed substantially continuously over the entire periphery of the margin 10 on the second sealing resin sheet 30. Sealing resin sheet piece 40 and a sealing resin sheet piece 41 overlapped with the sealing resin sheet piece 41 are arranged, and the first sealing resin sheet 20 is stacked thereon. By arranging the sealing resin sheet piece 40 continuously over the entire circumference at a position at the same height as the solar cell 4, uniform filling of the molten resin is possible, and generation of bubbles can be prevented. The sealing resin sheet piece 40 preferably has a width of at least 50% of the width of the margin portion 10, and more preferably has a width of at least 70%. The sealing resin sheet piece 40 may be composed of a plurality of sheet pieces arranged in parallel. It is preferable to dispose the sealing resin sheet pieces 41 on the sealing resin sheet pieces 40 at a distance from each other, whereby the internal air can be discharged smoothly.

 In the example of FIG. 2, sealing resin sheet pieces 42 and 43 are arranged on second sealing resin sheet 30 in gap 9 between solar cells 4. Here, two sealing resin sheet pieces are arranged in an overlapping manner. By arranging the sealing resin sheet pieces 42 and 43 in the gap 9 between the solar cells 4, when the inside is depressurized, the load due to the atmospheric pressure from both the front and back surfaces directly applies to the solar cells 4. The sealing resin sheet pieces 42 and 43 that receive the load receive the load. Then, as the temperature rises, the resin is softened and the thickness of the encapsulating resin sheet pieces 42 and 43, which have a strong load, decreases, and the solar cell 4 or the conductor 8 becomes It comes into contact with the sealing resin sheet 20 and the second sealing resin sheet 30. At that time, since the entire resin sheet is softened, the solar cell 4 or the conducting wire 8 that is not subjected to a local load is tightly attached so as to be embedded in the softened sealed resin sheet. This can prevent cell cracking in the pressure reduction step. The situation at this time is schematically shown in FIGS. Fig. 5 is an enlarged cross-sectional schematic view of the laminate before the start of the sealing operation, Fig. 6 is an enlarged cross-sectional schematic view of the laminate during heating and heating, and Fig. 7 is an enlarged cross-sectional view of the laminate after the sealing operation. It is a cross section schematic diagram. In this case, it is possible to reliably receive loads from above and below in the vicinity of the individual solar battery cells 4, so that cell cracking can be effectively prevented.

The width of the sealing resin sheet pieces 42 and 43 arranged in the gap 9 is preferably smaller than the width V of the gap 9 by V. By doing so, the thickness of the sealing resin sheet pieces 42, 43, which is thicker than the solar cell 4, can be easily spread over the entire gap 9 with a constant thickness. When the molten resin moves over a wide area, the solar cell 4 also moves with it. There is. The width is adjusted in consideration of the thickness of the solar cell 4 and the sealing resin sheet pieces 42 and 43, the area of the gap 9, and the like. Preferably, the width of the gap 9 is 0.1 to 0.95. It is twice. More preferably, it is 0.3 times or more and 0.9 times or less. If it exceeds 0.95 times, the disposing operation becomes difficult, and the solar cell 4 or the conducting wire 8 may be damaged at the time of decompression. Conversely, if the ratio is less than 0.1, it may be difficult to spread the molten resin uniformly. The length of the sealing resin sheet pieces 42 and 43 is not particularly limited, and may be shorter than one side of the solar cell 4 and may be V, and may extend from one end of the solar cell module to the other end. It may be taped.

It is also preferable that the internal air can be discharged from between the sealing resin sheet pieces arranged in the gap 9. By securing a passage for actively discharging the internal air, the remaining air bubbles can be suppressed, and a solar cell module with a good appearance can be manufactured. At this time, in the case where the sealing resin sheet pieces have a configuration in which a plurality of sealing resin sheets are laminated, at least one of the sealing resin sheet pieces has an interval between the resin sheet pieces, and the internal It is sufficient if air can be exhausted. When the sealing resin sheet pieces are arranged so as to cross each other, the internal air can be discharged from a thin portion other than the crossing portion.

 As described above, in order to effectively prevent cell cracking, it is preferable to dispose the sealing resin sheet pieces 42 and 43 in the gap 9 between the solar cells 4. Usually, such a configuration is suitable when the width of the gap 9 is preferably 5 mm or more, more preferably 10 mm or more, and still more preferably 20 mm or more. If the width of the gap portion 9 is narrow, it is difficult to arrange the sealing resin sheet pieces 42 and 43, so that the sealing resin sheet pieces are only provided in the margin 10 outside the solar cell 4. It is better to arrange. Such a configuration is suitable when the width of the gap 9 is preferably 10 mm or less, more preferably 5 mm or less, and still more preferably 3 mm or less.

After the sealing resin sheet pieces 40, 41, 42, 43 are placed in this manner, the first sealing resin sheet 20 is placed thereon. The preferable configuration and the preferable thickness of the first sealing resin sheet 20 are the same as those of the second sealing resin sheet 30. In the example of FIG. 2, three sealing resin sheets 21, 22, and 23 are stacked to form a first sealing resin sheet 20. Finally, on the first sealing resin sheet 20 The light-receiving-surface-side transparent plate 2 is placed on the light-receiving surface.

 Next, the example of FIG. 3 will be described. The example of FIG. 3 is an example in which both the light receiving surface side transparent plate 2 and the back plate 3 are curved. FIG. 3 is a schematic cross-sectional view of an example of the stacked body 60 before the sealing operation, and shows a cross section cut in parallel to a direction in which a plurality of solar cells 4 are connected in series. . In the example of FIG. 3, the operation of superimposing the force on the light-receiving-surface-side transparent plate 2 is performed. However, the reverse operation may be performed after the lower surface plate 3 is firstly disposed. At this time, from the viewpoint of workability, it is preferable to arrange the light receiving surface side transparent plate 2 or the back surface plate 3 so that the concave side faces upward, and to overlay the sealing resin sheet thereon.

 In the example of FIG. 3, the first sealing resin sheet 20, the solar cell 4, the sealing resin sheet pieces 40, 41, 42, 43, and the second sealing resin The force for stacking the resin sheet 30 in this order The specific method is the same as in the example of FIG. Finally, the back plate 3 is placed on the second sealing resin sheet 30. At this time, the back plate 3 preferably has a curvature having substantially the same radius of curvature as the light-receiving-surface-side transparent plate 2, and is stacked with the convex surface facing downward.

 When at least one of the light receiving surface side transparent plate 2 and the back surface plate 3 is curved as in the example of FIG. 3, the laminate 60 can be uniformly heated by the heat transfer from the heater. Because of the difficulty, it is particularly preferable to employ the production method of the present invention. In order to prevent the light-receiving-side transparent plate 2 or the back plate 3 from breaking due to uneven loads from above and below, the sealing treatment container 61 should be a bag made of a gas-impermeable flexible sheet. Like,.

 Next, the example of FIG. 4 will be described. The example of FIG. 4 is an example in which a countersunk hole 52 is provided in the back plate 3 and a module mounting bracket 53 is inserted therein. FIG. 4 is a schematic cross-sectional view of an example of the laminate 60 before the sealing operation, and shows a cross section cut in parallel to a direction in which a plurality of solar cells 4 are connected in series. The stacking order is not particularly limited. However, it is preferable to stack the module mounting bracket 53 so that the tip end 54 of the module mounting bracket 53 is protruded so that the side of the module mounting bracket 53 is on the upper side. Therefore, in the example of FIG. 4, it is more preferable to perform an operation in which the light receiving surface side transparent plate 2 is placed downward and the force is also superimposed.

In the example of FIG. 4, the first sealing resin sheet 20, the solar cell 4, the sealing resin sheet pieces 40, 41, 42, 43 and the second sealing resin The resin sheet 30 is stacked in this order 1S The specific method is the same as that of the example of FIG. Finally, the back plate 3 having the countersink hole 52 is placed on the second sealing resin sheet 30, and at this time, the head 55 of the module mounting bracket 53 is fitted into the countersink hole 52. To be By placing the head 55 of the module mounting bracket 53 inside the solar cell module 1 before sealing, the module mounting bracket 53 can be firmly fixed without making a hole in the transparent plate 2 on the light-receiving surface. can do. Although the form of the module mounting bracket 53 is not particularly limited, it is preferable that the module mounting bracket 53 has a head 55 shaped so as to be able to follow the countersunk hole 52. Further, threading or the like may be appropriately performed.

 The configuration of the laminate 60 before the sealing operation has been described above with reference to FIGS. Subsequently, the air between the light receiving surface side transparent plate 2 and the back plate 3 is exhausted, heated to melt the resin, and then cooled and sealed. At this time, it is preferable that the resin is heated to melt the resin, the crosslinking reaction proceeds, and the resin is cooled and sealed.

 FIG. 8 is a schematic view of an example of the sealing apparatus. This sealing treatment apparatus has a plurality of sealing treatment containers 61 accommodating a laminate 60 therein, and is capable of performing an air discharging operation and a heating operation. At this time, part or all of the sealing processing container 61 is made of a gas-impermeable and flexible film. The material of the membrane is a flexible membrane that is impermeable to gas and has a certain degree of flexibility and strength, and when the inside of the membrane is evacuated, the external pressure is evenly applied to the entire laminate 60. There is no particular limitation as long as it can be used, and a sheet or film of a rubber resin can be used. At this time, it is preferable to use a bag made entirely of a gas-impermeable flexible membrane. In this case, since the sealing container 61 is merely a bag, it can flexibly cope with the production of solar cell modules of various shapes and dimensions, and can be used for products of various dimensions such as building materials. It is suitable for applications that require the production of

In particular, when at least one of the light receiving surface side transparent plate 2 and the back surface plate 3 in the laminate 60 is curved, it is preferable to use such a sealing treatment container 61. When the inside of the container 61 is decompressed and a vertical load is applied to the laminate 60, the light-receiving-side transparent plate 2 or the back plate 3 can be prevented from breaking. In this case, it is preferable that the bag, which is the sealing processing container 61, be sealed along the surfaces of the transparent plate 2 on the light-receiving surface side and the back plate 3 with a force. [0067] Also, when the laminate 60 has a member protruding outward from the light-receiving-surface-side transparent plate 2 or the back plate 3, it is preferable to use such a sealing treatment container 61. Also in this case, it is preferable to seal the bag, which is the sealing processing container 61, after conforming to the shape of the protruding member. Depending on the shape of the protruding member, a bag having a pocket corresponding to the shape may be used. In order to prevent an excessive load from being applied to the protruding portion, it is also preferable to cover the protruding portion with a cover that is not easily deformed when depressurizing, and then introduce the protruding portion into the sealing treatment container 61. By doing so, it is also possible to prevent the sealing processing container 61 from being damaged.

 When the laminate 60 is introduced into the sealing treatment container 61, the outer edge of the laminate 60 is covered with a bleeder 62 made of a gas-permeable material, and the molten resin inside the laminate 60 flows out. In addition, it is preferable to secure the air discharge route for the air inside the laminate 60 as well as to prevent the air flow. As a material used for the leader 62, a woven fabric, a knitted fabric, a non-woven fabric or the like can be used.

 [0069] The plurality of sealing treatment containers 61 in which the laminates 60 are put in this way are introduced into the oven 63, and are arranged in parallel at intervals. Thus, the laminates 60 in the sealing container 61 are arranged in parallel with each other. It is preferable that the plurality of sealing processing containers 61 are arranged one above the other with a space therebetween in the vertical direction. The method of arranging at predetermined intervals is not particularly limited, and a method of providing shelves with predetermined intervals in the oven 63 is exemplified.

[0070] The laminate 60 is heated by flowing hot air in a direction parallel to the laminate 60 in the oven 63. By flowing hot air in a direction parallel to the laminate 60, heat can be efficiently and uniformly transmitted to the laminate 60. At this time, it is preferable that the hot air also comes into contact with the lower surface of the sealing treatment container 61. For this purpose, a method of disposing a spacer between the sealing treatment container 61 and the shelf, A method of using a net as a shelf is suitably adopted. The method for supplying the hot air is not particularly limited, and a heater may be provided in the oven 63 and the hot air may be flown in a direction parallel to the stacked body 60 using a fan. It is preferable to provide a heater outside the oven 63 while applying pressure, and to introduce hot air into the oven 63 because heating can be easily performed uniformly. In this case, the oven 63 has a hot air inlet and a hot air outlet provided on the opposite side, and a plurality of ovens are provided between passages flowing from the hot air inlet to the hot air outlet. It is preferable that the sealing processing container 61 is disposed. Further, it is preferable to heat the laminate while maintaining the inside of the oven 63 at substantially the atmospheric pressure in view of the cost of the apparatus.

[0071] In many solar cell modules, a plurality of sets in which a plurality of solar cells 4 are connected to each other in a series direction by a conductor 8 are prepared, and these sets are arranged in parallel at intervals. The laminate 60 is manufactured. The relationship between the orientation of the laminate 60 and the direction of the airflow in the oven 63 is important for manufacturing a solar cell module in which the solar cells 4 are regularly arranged. FIG. 9 shows a case where the heating is performed so that the air flow in the oven 63 is parallel to the series direction. FIG. 10 shows a case where the heating is performed so that the air flow in the oven 63 is oriented in a direction perpendicular to the in-line direction. The arrows in FIGS. 9 and 10 indicate the direction of the airflow. As will be described in a later embodiment, when heating is performed so that the air flow in the oven 63 is oriented in a direction perpendicular to the series direction, the rows of the solar cells 4 connected in series are arranged as shown in FIG. It turned out to be curved like the dashed line inside. This is considered to be due to the distribution of the speed at which heat is transmitted in the laminate 60. Therefore, in order to manufacture a regularly arranged solar cell module, it was revealed that it is preferable to heat the oven 63 so that the air flow in the oven 63 is in a direction parallel to the serial direction.

 At the time of the sealing process, the pressure between the light receiving surface side transparent plate 2 and the back surface plate 3 is exhausted by reducing the pressure in the sealing process container 61. In the sealing apparatus shown in FIG. 8, a pipe 64 for exhausting air is connected to each sealing chamber 61. The three pipes 64 are connected together and connected to the pipe 65! Furthermore, six pipes 65 (partially omitted from the drawing) assembled in this way are connected to the tank 66. The tank 66 is connected to a vacuum pump 67 so that the air inside the sealed processing container 61 can be discharged. The number of the sealing containers 61 is not particularly limited as long as it is plural, but in consideration of production efficiency, it is preferably 6 or more, and more preferably 12 or more.

[0073] Each of the six pipes 65 is connected to a pressure gauge 69 via a valve 68, and is provided with an electromagnetic valve 70 capable of cutting off the flow in the pipe 65. As a result, when a leak occurs in any of the sealed processing containers 61 connected to the pipe 65, the pressure gauge 69 detects an increase in pressure, and the control circuit 71 sends a signal to the solenoid valve 70 to send a signal. Solenoid valve 70 close. Accordingly, even if a leak occurs in one sealing processing container 61 during the sealing operation, it is possible to prevent the other sealing processing container 61 from being adversely affected. The sealing treatment container 61 used in the present invention is made of a flexible sheet, and it is necessary to prepare various shapes according to the form of the solar cell module, so that leakage may occur. . Moreover, solar cell modules are quite expensive. Therefore, it is preferable to adopt such a control method. In the example of FIG. 8, the force that performs one control for each of the three sealed processing containers 61 is based on the balance between the equipment cost and the effect. The number of sets of the pressure gauge 69 and the solenoid valve 70 may be two or more, but is preferably three or more, and more preferably five or more. An alarm signal can be output from the control circuit 71 to notify the operator.

[0074] The six pipes 65 are connected to the tank 66, and when the solenoid valve 70 is open, all the sealing treatment containers 61 are in communication with the tank 66. The air in the tank 66 is discharged by a vacuum pump 67. Further, outside air can be introduced into the tank 66 through the control valve 72.

 As will be described later, the pressure in the sealing container 61 needs to be strictly controlled.

 In the sealing treatment apparatus shown in FIG. 8, the pressure inside all the sealing treatment containers 61 can be controlled simultaneously by controlling the pressure inside the tank 66. The pressure inside the tank 66 is measured by a pressure gauge 74 connected via a valve 73, and a control circuit 75 receiving the pressure data sends a signal to the control valve 72 to take in the outside air to achieve a desired pressure. adjust. During this time, the vacuum pump 67 continues to operate. By performing control while taking in outside air into the tank 66 having a relatively large capacity, fine adjustment of the pressure in the sealing processing container 61 is possible.

 Further, before starting the depressurizing operation in the sealing processing container 61, the vacuum pump 67 is operated with the solenoid valve 70 and the control valve 72 closed so that the pressure in the tank 66 is reduced in advance. You can keep it. In this case, the air in the sealed processing container 61 can be quickly discharged by opening the solenoid valve 70. Thus, even if the exhaust capability of the vacuum pump 67 is small, it is useful to quickly reduce the pressure in the sealing processing container 61.

[0077] The capacity of the tank 66 is not particularly limited, but is preferably 10 liters or more. More preferably, it is 20 liters or more. If the capacity is too large, pressure control by the control valve 72 may not be able to be performed quickly. Therefore, the pressure is preferably 500 liter or less. The sealing apparatus used in the examples described later was equipped with a 50-liter tank 66! / ヽ.

 As described later, it may be preferable to preheat the inside of the sealing processing container 61 before reducing the pressure. In such a case, a preheating operation can be performed in the oven 63. A temperature control chamber (not shown) adjacent to the power oven 63 is provided, and the preheating operation is performed in the temperature control chamber. It is preferable from the viewpoint of the utilization efficiency of the oven 63 that the sealing treatment is performed in the inside. In this way, it is possible to preheat other modules while sealing the module in the oven 63.

 When the sealing resin is melted in the sealing processing container 61 and then cooled under the atmospheric pressure, the cooling can be performed in the oven 63 or externally. It is also possible. However, when cooling in the oven 63, the use time of the oven 63 is prolonged, so that the productivity is reduced. On the other hand, when cooling is performed externally, it becomes difficult to adjust the cooling rate. Therefore, it may be preferable to provide a temperature control chamber adjacent to the oven 63, perform a sealing process in the oven 63, and then cool in the temperature control chamber. This makes it possible to cool other modules while sealing the modules in the oven 63. In particular, the effect is great when it is desired to reduce the cooling rate.

 [0080] The temperature control chamber is not particularly limited as long as it can control the internal temperature and is provided adjacent to the oven 63. The external force also preferably has a door for introducing the sealing treatment container 61 into the temperature control room, and preferably has a door between the oven 63 and the temperature control room. For example, it is possible to use a device that can move a carriage on which a large number of the sealing processing containers 61 are placed, and guide the carriage from the outside to the oven 63 via the temperature control chamber. For one oven 63, only one temperature control room may be provided, or two or more temperature control rooms may be provided.

When one temperature control chamber is provided, it can be used for either a preheating operation or a cooling operation. For example, the sealing treatment container 61 is introduced from outside into the temperature After performing the operation, the product is introduced into the oven 63, sealed, and then can be led out. Alternatively, the sealing treatment container 61 can be introduced into the oven 63 from the outside, subjected to the sealing treatment, then introduced into the temperature control chamber, and cooled, and then taken out. In this case, the sealing container 61 normally passes in one direction.

 When two temperature control chambers are provided, the temperature control chambers 61 may pass through the sealing treatment container 61 in one direction or may reciprocate. When passing the sealing treatment container 61 in one direction, the sealing treatment container 61 is introduced into the temperature control chamber from the outside, a preheating operation is performed, and the sealing treatment container 61 is introduced into the oven 63. After being introduced into the temperature control room and performing a cooling operation, it is led out. When reciprocating the sealing container 61, the sealing container 61 is introduced from the outside into the temperature control chamber, pre-heated, introduced into the oven 63, sealed, and then subjected to the same temperature adjustment. Return to the room, perform the cooling operation, and then take it out. In this case, the cooling operation and the preheating operation are performed in the temperature control room 1 and the sealing process is performed in the oven 63 when the cooling operation and the preheating operation are performed in the other temperature control room. To perform the sealing process. In the case of reciprocating in this manner, there is an advantage that a space for circulating the cart is not required.

 Using the sealing device described above, the air between the light-receiving surface side transparent plate 2 and the back plate 3 is exhausted, heated to melt the resin, and cooled by force to seal. I do. The temperature condition at this time is not particularly limited, and if the temperature is raised to a temperature at which the resin can be melted, the resin may be heated to a temperature higher than the melting point of the resin if the resin is crystalline. If the sealing resin is a crosslinkable thermoplastic resin, the temperature is raised to a crosslinkable temperature and maintained at a crosslinkable temperature for a predetermined time. The pressure is not particularly limited as long as the pressure can be reduced to such a level that the air in the laminate 60 can be exhausted and the residual air bubbles can be reduced.

[0084] Above all, when sealing in the sealing treatment container 61, a step of heating the sealing resin while maintaining the pressure in the sealing treatment container 61 at 0.05 MPa or more (Step 1), Step of reducing the pressure inside the sealing vessel 61 to a pressure of 0. OlMPa or less (Step 2) at a temperature lower than the melting point of the fat (Step 2). It is preferable to perform a sealing operation including a step (step 3), a step of increasing the pressure in the sealing container 61 (step 4), and a step of cooling (step 6). [0085] Step 1 is a step of heating the sealing resin while maintaining the pressure in the sealing processing container 61 at 0.05 MPa or more. By maintaining the pressure in the sealing treatment container 61 at 0.05 MPa or more, the vertical force of the laminate 60 can also be prevented from applying a large load to the cell. More preferably, the pressure is at least 0.06 MPa. If the sealing resin sheet piece is placed only in the margin 10 outside the solar cell 4 and the sealing resin sheet piece is not placed in the gap 9 between the solar cells 4, cell cracking may occur. It is preferred to adopt step 1 to prevent this. When the transparent plate 2 on the light-receiving surface side or the back plate 3 is made of unstrengthened bent glass, it is preferable to adopt Step 1 in order to prevent breakage of the plate. In the case where the sealing is performed and a sealing resin sheet piece is arranged in the gap 9 between the solar cells 4, it is preferable to omit the step 1 from the viewpoint of production efficiency.

 [0086] The pressure in the sealing treatment container 61 in step 1 may be atmospheric pressure (0. IMPa), but by reducing the pressure to, for example, 0.09 MPa or less, the leakage of the sealing treatment container 61 may be reduced. You can check. In step 1, since the sealing resin has not been melted yet, if there is a leak in the sealing processing container 61, it can be repaired at this stage. Since the sealing container 61 used in the manufacturing method of the present invention is formed of a flexible sheet and is easily broken, it is preferable to slightly reduce the pressure in this manner. When reducing the pressure from the atmospheric pressure to a predetermined pressure of 0.05 MPa or more, it is preferable that the time required for the pressure reducing operation is 10 minutes or more. Although a large load is not applied, sudden decompression operation may cause cell cracking.

As described above, the sealing resin is softened in advance by heating the sealing resin in a state where the pressure in the sealing processing container 61 is high. The temperature reached by the heating at this time is a temperature at which the elastic modulus decreases while the sealing resin does not melt. Here, the temperature at which the sealing resin does not melt generally means a temperature lower than the melting point (Tm), preferably (Tm-5) ° C or less, more preferably (Tm-5) ° C. 10) It is below ° C. If the sealing resin does not have a melting point, the melting point may be replaced with a glass transition point or a softening point here. A suitable temperature for many sealing resins is 65 ° C. or less, and a more preferred temperature is 60 ° C. or less. If the temperature is too high, the flow of the resin starts before the pressure in the sealing treatment container 61 drops to 0. There is a possibility that the passage for discharging the air is blocked and air bubbles remain. The temperature reached by the heating is preferably (Tm−30) ° C. or more, more preferably (Tm−20) ° C. or more. For many sealing resins, the preferred temperature is 40 ° C. or more, and the more preferred temperature is 45 ° C. or more. If the temperature is too low, the elastic modulus of the sealing resin is not sufficiently reduced, and if the pressure in the sealing container 61 is reduced in step 2, cell cracking may occur. It is preferable to maintain the temperature in such a temperature range for 5 minutes or more and to start the depressurizing operation in step 2 with the force.

 [0088] Step 2 is a step of reducing the pressure in the sealing treatment container 61 to a pressure of not more than 0.1 OlMPa at a temperature lower than the melting point of the sealing resin. It is a process that is performed continuously. By reducing the pressure at a temperature lower than the melting point of the sealing resin, a passage through which the air inside the laminate 60 is discharged is secured. At this time, the pressure in the sealing container 61 is preferably reduced to 0.005 MPa or less. By sufficiently reducing the pressure, the remaining air bubbles after sealing can be effectively suppressed. The temperature during the pressure reduction in step 2 from 0.05 MPa to 0.0 OlMPa is preferably maintained in the same temperature range as the temperature reached by the heating described in step 1. Also, in order to prevent cell cracking due to a rapid pressure reduction operation, it is preferable to slowly reduce the pressure from 0.05 MPa to 0.0 OlMPa over 5 minutes or more.

 [0089] Step 3 is a step in which the temperature is raised to a temperature equal to or higher than the melting point of the sealing resin while the pressure is reduced, and is a step performed after step 2. When the temperature of the sealing resin is raised, the elastic modulus is greatly reduced near the melting point and changes to a highly viscous liquid.However, step 3 is a step in which the pressure is reduced until such temperature is reached. . If the pressure is reduced and the pressure is increased while the elastic modulus is high, air may flow into the inside of the laminate 60, and air bubbles may remain in the sealing resin. Here, the lower limit of the temperature reached by the temperature raising operation in step 3 is preferably (Tm + 10) ° C or more, and more preferably (Tm + 20) ° C or more. The preferred lower limit of many sealing resins is at least 80 ° C, more preferably at least 85 ° C. The upper limit is usually 200 ° C or less.

[0090] In step 3, the rate of temperature rise is preferably slow, and the time required to raise the temperature from room temperature to the above temperature is preferably 15 minutes or more, and is preferably 30 minutes or more. Better More preferably, it is one hour or more. By slowly raising the temperature, it is possible to efficiently prevent cell cracks that occur when the load is suddenly increased. At this time, the heating rate may be changed midway, or a balancing operation may be performed to stop the heating and cancel the temperature distribution inside the stacked body 60. From the viewpoint of productivity, the heating time is usually less than 20 hours.

 [0091] Step 4 is a step of increasing the pressure inside the sealing container 61, and step 6 is a step of cooling, and both are steps performed after step 3. Either step 4 or step 6 may be performed first, or both steps may be performed simultaneously.

 [0092] In step 4, it is preferable that the pressure be increased slowly, and the time required for the pressure increase be 5 minutes or more, more preferably 10 minutes or more, and more preferably 20 minutes or more. More preferred. From the viewpoint of productivity, the pressurization time is usually 5 hours or less, preferably 2 hours or less. The pressure after the pressure can be increased to the same pressure as the atmospheric pressure (0. IMPa), which is preferably 0.05 MPa or more, more preferably 0.07 MPa or more. At this time, the pressure may be increased stepwise. If the temperature at the time of increasing the pressure in step 4 is too high, the molten resin may flow unnecessarily, and the cells may move. Usually, it is preferably 120 ° C or lower, more preferably 100 ° C or lower.

 [0093] Further, it is preferable that the step 4 includes a step of simultaneously raising the temperature while increasing the pressure in the sealing processing container 61. By doing so, the pressure applied to the laminate 60 can be gradually released in the process of gradually increasing the fluidity, and the molten resin flows unnecessarily while suppressing the generation of residual air bubbles. It is effective in suppressing In this case, the temperature at the start of boosting is (1¾1 10) to (1¾1 + 20), more preferably (Tm-5) ° C to (Tm + 15) ° C, and 3 to 30 It is desirable to increase the pressure while increasing the temperature by 5 ° C, more preferably 5 to 20 ° C. The temperature rise rate (° CZ minute) vs. the pressure rise rate (MPaZ minute) it should be 0.001 to 0.1 (MPa / ° C), and 0.002 to 0.05 (MPa / ° C) is more preferable! / ,.

[0094] In the cooling step of step 6, cooling is usually performed to around room temperature. However, if the cooling rate is too fast, the glass may be cracked. Therefore, cooling is preferably performed for 10 minutes or more, more preferably for 30 minutes or more. I do. Above all, when melting the sealing resin (melting point: Tm (° C)) and cooling it with ( It is preferable to perform cooling so that the time required for cooling from Tm + 10) ° C to (Tm−20) ° C is 20 minutes or more. The above-mentioned time is more preferably 30 minutes or more, and still more preferably 60 minutes or more. By cooling slowly around the melting point, residual stress can be suppressed and cell cracking can be suppressed.

 [0095] The main cause of cell cracking in the sealing operation is that when air is discharged between the light-receiving surface side transparent plate 2 and the back surface plate 3 to melt the resin, a load is applied in the vertical direction. It is believed to be due to However, the present invention shows that cell cracking does not occur at that timing, and that there may be cell breakage during subsequent cooling while undamaged solar cells exist in the molten resin. Found them. This is because, during the sealing operation, when the laminate at a temperature higher than the melting point was observed, no cell cracking was found. This phenomenon has been clarified by the recognition of the phenomenon that occurs.

 [0096] The mechanism by which such a phenomenon occurs is not necessarily clear, but the following mechanism is estimated. When the sealing resin in the molten state is cooled, it loses fluidity at a temperature lower than the melting point, and solidifies and contracts. It is considered that such shrinkage occurs mainly due to crystallization of the polymer. At this time, it is estimated that cell cracking has occurred due to the stress assumed to be generated inside the resin due to the shrinkage.収縮 It is surprising that the shrinkage stress accompanying the solidification of the resin is a large force that can destroy the cell. On the other hand, it has been clarified that the occurrence of cell cracking at this timing can be suppressed by reducing the cooling rate. The reason why cell cooling can be suppressed by lowering the cooling rate is not necessarily clear, but it is possible that the rate of crystallization can be reduced or that stress relaxation can easily progress. Here, when the sealing resin does not have a melting point, the melting point mentioned here may be replaced with a glass transition point or a softening point. Even when the sealing resin is an amorphous resin having no melting point, it solidifies with shrinkage near the glass transition point or the softening point.

[0097] In particular, when a fragile solar cell is used, it is preferable to use a method of cooling slowly as described above to seal the cell. For example, a solar cell with a large area, a solar cell with a small thickness, a solar cell with light-transmitting small holes, or an uneven surface It is suitable for sealing a solar cell or the like having the same.

 [0098] When a crosslinkable thermoplastic resin is used as the sealing resin, after the step (step 3) of raising the temperature to near the melting point of the sealing resin while reducing the pressure, the sealing is performed. After the step of increasing the pressure in the processing vessel 61 (step 4), the process must have a step of raising the temperature to a temperature range where the crosslinking reaction proceeds (step 5) and a step of cooling (step 6). Is preferred.

 [0099] In this case, after increasing the pressure in the sealing treatment container 61 in step 4, the temperature is once cooled to a temperature equal to or lower than the melting point, and then increased in step 5 to a temperature range in which the crosslinking reaction proceeds. Is also preferred. After the pressure is increased, it is possible to raise the temperature to the temperature range where the crosslinking reaction proceeds.However, once the cooling is performed, the time during which the residual stress is relaxed can be secured, and the molten resin protrudes. Sinking (the part where the resin is missing at the end) and cell movement can be more effectively suppressed. At this time, it is preferable to cool the resin until the resin loses sufficient fluidity, and it is preferable to cool the resin to (Tm-10) ° C or lower, more preferably to (Tm-20) ° C or lower.

 [0100] As described above, after increasing the pressure in the sealing treatment container 61, the temperature is raised to a temperature range in which the crosslinking reaction proceeds in step 5, and the crosslinking reaction proceeds. The crosslinking reaction is usually carried out by heating to 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and still more preferably 140 ° C. or higher. In order to prevent deterioration of the resin, a crosslinking temperature of 200 ° C or less is usually adopted. The time for keeping the temperature range in which the crosslinking reaction proceeds varies depending on the desired degree of crosslinking and the like, but is usually 5 minutes to 2 hours, preferably 10 minutes to 1 hour.

[0101] The pressure in the sealing container 61 when the crosslinking reaction proceeds in step 5 is preferably 0.05 MPa or more, more preferably 0.06 MPa or more. By increasing the pressure in the sealing processing container 61, the pressure applied from above and below can be reduced. Since the crosslinking reaction proceeds at a high temperature, the melt viscosity of the sealing resin at that time is considerably lower than that near the melting point. Therefore, at this time, it is important that the vertical force does not apply unnecessary pressure and the movement of the cell and the protrusion of the resin are suppressed. If the pressure is increased to the same pressure as the atmospheric pressure while applying pressure, sink marks may occur depending on the configuration of the laminate 60. In such a case, it is preferable to set the pressure to a pressure lower than the atmospheric pressure. Also, when the pressure is increased to the same pressure as the atmospheric pressure, it becomes difficult for the bleeder 62 to press around the laminate 60, and the resin overflows. In some cases, it is preferable to set the pressure lower than the atmospheric pressure and the pressure. In this case, the pressure is preferably lower than atmospheric pressure by 0.001 MPa or more, and preferably lower than 0.0 OlMPa (in this case, 0.09 MPa or less). In the present invention, ヽ ぅ atmospheric pressure は means a state in which 加 圧 atmospheric pressure is positively applied or decompressed, for example, in order to forcibly blow hot air into the oven 63 with a fan, and Even if it is too high, it is substantially the same as atmospheric pressure.

 [0102] After the cross-linking reaction is allowed to proceed in step 5, it is subjected to the cooling step in step 6. The cooling process 6 is as described above.

 [0103] The solar cell module thus obtained is filled with the sealing resin up to the periphery of the module, and has no spacer at the periphery of the sealing resin layer. Since the peripheral portion can be sealed with a sealing resin having excellent adhesion and durability, a highly reliable solar cell module can be provided. The thickness of the sealing resin layer is preferably 2 to 6 mm in total. More preferably, it is 3 mm or more and 5 mm or less.

 According to the production method of the present invention, the sealing operation can be performed even when at least one of the light-receiving-surface-side transparent plate 2 and the back plate 3 is curved. In this case, since a solar cell module sandwiched between bent glass can be provided, it is possible to meet a demand for diversification of a building design. Further, a metal fitting for fixing the module is provided, and the metal fitting is inserted into a through hole formed in a gap between the transparent plate on the light receiving surface side and the rear plate, and an end on the head side of the metal fitting is sealed with a sealing resin layer. A solar cell module disposed on the side and having the opposite end of the metal fitting protruding outward can also be provided. This makes it possible to provide a solar cell module that can be applied to the DPG method that has been widely used in recent years.

 Further, in the solar cell module of the present invention, the plurality of solar cells 4 are regularly arranged between the light receiving surface side transparent plate 2 and the back surface plate 3 so as not to be damaged. Since a large number of solar cells 4 can be sealed with resin without damage, a large solar cell module can be provided. In addition, since the residual air bubbles are suppressed, the resin is prevented from protruding from the ends, and they are properly aligned and have a beautiful appearance, they are suitably used for the outer walls, roofs, windows, etc. of various buildings.

Example [0106] Example 1

 As the solar cell 4, 40 square polycrystalline silicon solar cells of 125 mm X I 25 mm X O. 35 mm were used. The four corners are chamfered by several mm. As the conductor 8, a solder dip copper ribbon wire manufactured by Hitachi Cable, Ltd. was used. The width of the ribbon wire is 1.5 mm and the thickness is 0.15 mm. Solder is printed in advance on the portion of the solar cell 4 where the light-receiving surface 6 and the back surface 7 are bonded to the conductor 8. One end of the conductor 8 was overlapped and soldered on the solder printing portion of the light receiving surface 6 of the solar cell 4, and the other end was overlapped and soldered on the solder printing portion of the back surface 7 of the adjacent solar cell 4. Adjacent cells were connected by two conductors 8 so that the distance between them was 50 mm. That is, the width of the gap 9 is 50 mm.

 [0107] As the back plate 3, a 1000 mm x 1500 mm x 10 mm float plate reinforced glass (blue plate glass) was used. The surface compressive stress of the tempered glass is 100MPa. As an encapsulating resin sheet, a 0.6 mm thick Solar Eva SC36J manufactured by Hi-Sheet Industry Co., Ltd. was used. The encapsulating resin sheet was made of ethylene-vinyl acetate copolymer (EVA). It contains a crosslinking agent, a silane coupling agent, a stabilizer, etc., and the melting point of the resin before crosslinking is 71 ° C as measured by the DSC method. And a depth of about 45 m with an embossed pattern (pearskin), and two sealing resin sheets 31 and 32 having dimensions of 1000 mm and 500 mm were stacked on the back plate 3. The two sealing resin sheets 31 and 32 constitute a second sealing resin sheet 30 having a thickness of 1.2 mm.

 [0108] The plurality of solar cells 4 connected to each other in the manner described above were placed on the second sealing resin sheet 30, and arranged vertically and horizontally as shown in FIG. The width of the gap 9 between the adjacent solar cells 4 was set to 50 mm both vertically and horizontally. The width of the margin 10 outside the solar cell 4 is 75 mm in the longitudinal direction (the direction in which eight cells are arranged) and 87.5 mm in the width direction (the direction in which five cells are arranged). And

Subsequently, as shown in FIG. 12, the sealing resin sheet piece 44 was arranged in the gap 9 between the solar cells 4, and the sealing resin sheet piece 45 was arranged in the margin 10. The width of the sealing resin sheet piece 44 was 40 mm, and the width of the sealing resin sheet piece 45 was 60 mm. The sealing resin sheet piece 44 was disposed at a position near the center between the adjacent solar cells 4 so as to press the conductive wire 8. By arranging in the vicinity of the center in this way, the movement of resin when molten It can be reduced, and the solar cell 4 or the conductor 8 can be prevented from being damaged. The force can also prevent the solar cell 4 from moving until it is melted.

Further, as shown in FIG. 13, in the gap 9 between the solar cells 4, the upper sealing resin sheet piece 46 crosses over the lower sealing resin sheet piece 44. Was placed. The width of the upper sealing resin sheet piece 46 is 40 mm. In the margin 10, the upper sealing resin sheet piece 47 was disposed on the lower sealing resin sheet piece 45. The size of the upper sealing resin sheet piece 47 arranged on the side of the margin 10 is 60 mm X I 25 mm, and the upper sealing resin sheet piece 48 is also arranged at the corner. The total thickness of the sealing resin sheet piece at the intersection is 1.2 mm, and this portion can support the vertical load. The sealing resin sheet pieces 47 and 48 on the upper side of the margin 10 are intermittently arranged, and there is a gap except at the intersection, so that a passage for discharging the internal air can be secured, The rest can be prevented.

 [0111] After the sealing resin sheet pieces 44 to 48 were arranged as described above, two sealing resin sheets 21 and 22 having dimensions of 1000 mm x 1500 mm were stacked thereon. The two sealing resin sheets 21 and 22 constitute a first sealing resin sheet 20 having a thickness of 1.2 mm. A 1000 mm X 1500 mm X 10 mm float tempered glass (white sheet glass) was placed on the light receiving surface side transparent plate 2 thereon. The surface compressive stress of the tempered glass is 1 OOMPa.

 [0112] A sealing operation was performed using the laminated body 60 thus obtained and using the sealing apparatus shown in FIG. First, the entire periphery of the outer edge of the laminated body 60 was covered with a bleeder 62, put into a rubber bag serving as a sealing container 61, connected to a pipe 64, and put into an oven 63. At this time, as shown in FIG. 9, the airflow in the oven 63 was made parallel to the series direction of the solar cells 4 connected to each other.

[0113] After setting as described above, a sealing treatment operation of the following steps 2 to 6 was performed. The temperature and pressure at this time were controlled as shown in Table 1 and FIG. At this time, the temperature is the temperature in the oven 63 and the pressure is the pressure measured by the pressure gauge 74. It should be noted that step 1 which is a “step of heating the sealing resin while maintaining the pressure in the sealing processing vessel at 0.05 MPa or more” is not employed in this example. A sealing resin sheet piece is placed in the gap 9 between the solar cells 4, and a flat reinforcement is applied even if the light-receiving-side transparent plate 2 and the back plate 3 are misaligned. Since glass is used, cell cracking and substrate cracking can be prevented without using step 1.

 Step 2: “Step of depressurizing the inside of the sealing container to a pressure of 0.1 OlMPa or less at a temperature lower than the melting point of the sealing resin”

 From room temperature (27 ° C), the temperature was raised and the pressure was reduced. After about one minute, the pressure dropped to less than 0.005 MPa.

[0115] Step 3: "Step of raising the temperature to a temperature equal to or higher than the melting point of the sealing resin while reducing the pressure"

 Continue heating to 40 ° C in 30 minutes from the start of heating, maintain at 40 ° C for 10 minutes (balancing), increase the temperature by 50 ° C for 75 minutes, and raise the temperature at 50 ° C. Maintain for 10 minutes, increase the temperature to 60 ° C by applying 105 minutes, maintain at 60 ° C for 10 minutes, and raise the temperature to 71 ° C (melting point of sealing resin) over 120 minutes, 10 minutes Maintained.

 Step 4: “Step of increasing the pressure in the sealing treatment container”

 The temperature was raised from 71 ° C to 90 ° C over 90 minutes, and at the same time, the pressure, which was less than 0.005 MPa, was raised to 0.07 MPa over 90 minutes. At this time, the ratio of the pressure raising rate (MPaZ component) to the temperature raising rate (° CZ component) was 0.337 (MPaZ ° C). Thereafter, the temperature was maintained at 90 ° C for 30 minutes, cooled to 40 ° C over 60 minutes, and maintained at 40 ° C for 30 minutes, while maintaining the pressure of 0.07 MPa.

 [0117] Step 5: "Step of raising the temperature to a temperature range in which the crosslinking reaction proceeds to promote the crosslinking reaction" Subsequently, the temperature is raised from 40 ° C to 155 ° C over 90 minutes, and at 155 ° C for 36 minutes. The cross-linking reaction was allowed to proceed while maintaining. During this time, a pressure of 0.07 MPa was maintained.

[0118] Step 6: "Cooling step"

 Subsequently, it was cooled to 40 ° C from 155 ° C with 60 minutes of effort. When the temperature reached 40 ° C, the pressure was raised to 0.07MPa and to 0. IMPa (atmospheric pressure) in about 1 minute, and then removed from the hot stove 66.

[0119] [Table 1] Processing time Total time 1 DIL / s Pressure

 (Min) (min) (.C) (MPa)

 Process 2 1 1 0.1 → <0.005

 30 31

 10 41 40

 75 116 40 → 50

 10 126 50

 Process 3 pass 0.005

 105 231 50 → 60

 10 241 60

 120 361 60 → 71

 Dimension

 10 371 LTD LT 71

 90 461 71 → Dimension 9 Dimension 0 <0.005 → 0.07

30 491 90

 Process 4

 60 551 o

 30 581 40 g

 0.07

 90 671

 Process 5 o

 36 707 155

 60 767

 Process 6

 1 768 40

[0120] In the obtained solar cell module, no cracks or chips in the cells, no breaks in the conductive wires, and no residual air bubbles were observed, and no protrusion or sink of the sealing resin in the peripheral portion was observed. In addition, the solar cells were regularly arranged, and the curvature of the solar cells 4 connected in series by the conductor 8 was within 2 mm.

 [0121] Example 2

 In Example 1, a sealing process was performed in the same manner as in Example 1 except that the orientation of the laminate 60 was rotated by 90 degrees as compared with that in Example 1. That is, as shown in FIG. 10, the airflow in the oven 63 was set to be perpendicular to the series direction of the solar cells 4 connected to each other.

[0122] In the obtained solar cell module, cracking or chipping of the cell and disconnection of the conductive wire are completely eliminated. No residual foam was observed, and no protrusion or sink of the sealing resin in the peripheral portion was observed. However, the solar cells 4 connected in series with the conductor 8 were curved by about 10 to 20 mm as shown by the dashed line in FIG.

Claims

The scope of the claims

 [1] A method for manufacturing a solar cell module in which solar cells are sealed with resin between a light-receiving-side transparent plate and a back plate;

 A first sealing resin sheet covering substantially the entire surface of the transparent plate on the light-receiving surface is disposed between the transparent plate on the light-receiving surface and the solar cell, and the rear plate is substantially disposed between the rear plate and the solar cell. A second sealing resin sheet covering the entire surface is arranged to produce a laminate,

 The laminate is placed in a sealing treatment container made of a gas-impermeable flexible sheet, and a plurality of sealing treatment containers containing the laminate are introduced into an oven and arranged in parallel at intervals. And

 The inside of the sealing processing container is decompressed to discharge air between the light-receiving surface side transparent plate and the back plate, and the laminate is heated by flowing hot air in the oven in a direction parallel to the laminate. To melt the sealing resin,

 A method for manufacturing a solar cell module, wherein the sealing resin is solidified by successively cooling.

 2. The method for manufacturing a solar cell module according to claim 1, wherein the sealing treatment container is a bag made of a flexible gas-impermeable sheet.

3. The method for manufacturing a solar cell module according to claim 1, wherein the outer edge of the laminate is covered with a breathable fabric and then placed in a sealing container.

[4] The laminate according to claim 1, wherein the laminate is heated while maintaining the inside of the oven substantially at atmospheric pressure.

V, the manufacturing method of the solar cell module described in the description.

 [5] The method according to any one of claims 1 to 4, wherein a plurality of solar cells are arranged at intervals and connected to each other by a conductor.

V, the manufacturing method of the solar cell module described in the description.

 [6] A plurality of sets in which a plurality of photovoltaic cells are connected to each other in a series direction by a conducting wire are arranged in parallel at an interval to produce the stacked body, and the airflow in the oven is changed in the direction of the straight line. 6. The method for manufacturing a solar cell module according to claim 5, wherein the heating is performed in a direction parallel to the direction of the solar cell module.

7. The method for manufacturing a solar cell module according to claim 1, wherein the oven has a hot air inlet and a hot air outlet provided on the opposite side.

[8] The sealing process in which the sealing process container is connected to a vacuum pump via a pipe, and each of the plurality of pipes is provided with a set of a pressure gauge and a valve, and a leak is detected by the pressure gauge. 8. The method for manufacturing a solar cell module according to claim 1, wherein a valve connected to the container is closed.

 [9] The solar cell module according to any one of claims 1 to 8, wherein each of the sealing processing containers is connected to a vacuum pump via a pipe, and a tank is provided between the sealing processing container and the vacuum pump. Manufacturing method.

 10. The method for manufacturing a solar cell module according to claim 9, comprising a pressure gauge for measuring the pressure in the tank, and a valve for introducing outside air into the tank, and finely adjusting the pressure in the tank.

 [11] The method for manufacturing a solar cell module according to any one of claims 1 to 1, wherein at least one temperature control chamber is provided adjacent to the oven, and a preheating operation or a cooling operation is performed in the temperature control chamber.

 [12] The sealing resin sheet piece having a thickness larger than the thickness of the solar cell is disposed in the gap between the solar cells or in a margin outside the solar cell in the laminate. Eleven

V, the manufacturing method of the solar cell module described in the description.

13. The method for manufacturing a solar cell module according to claim 1, wherein the difference between the light-receiving-surface-side transparent plate and the rear surface plate is a glass plate.

14. The method for manufacturing a solar cell module according to any one of claims 1 to 13, wherein at least one of the light-receiving-side transparent plate and the back plate is curved.

15. The method for manufacturing a solar cell module according to any one of claims 1 to 14, wherein the laminate has a member protruding outward from the light-receiving-surface-side transparent plate or the back plate.

16. The method for manufacturing a solar cell module according to claim 15, wherein the member protruding outward is a metal fitting for fixing the module.

[17] The production of the solar cell module according to any one of claims 1 to 16, wherein the sealing resin is a resin selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl butyral, and polyurethane. Method.

[18] A step of heating the sealing resin while maintaining the pressure in the sealing processing container at 0.05 MPa or more when sealing in the sealing processing container (Step 1), wherein the temperature is lower than the melting point of the sealing resin. Sealed at temperature Depressurizing the inside of the sealing treatment container to a pressure of 0. OlMPa or less (step 2), raising the temperature to a temperature equal to or higher than the melting point of the sealing resin while maintaining the reduced pressure (step 3), The method for manufacturing a solar cell module according to any one of claims 1 to 17, wherein a sealing operation including a step of increasing pressure (step 4) and a step of cooling (step 6) is performed.

 [19] The sealing resin sheet is made of a crosslinkable thermoplastic resin, and when sealing in the sealing container, the inside of the sealing container is heated at a temperature lower than the melting point of the sealing resin. A step of reducing the pressure to the following pressure (step 2), a step of raising the temperature to a temperature equal to or higher than the melting point of the sealing resin while maintaining the reduced pressure (step 3), and a step of increasing the pressure in the sealing treatment container (step 4) performing a sealing operation in which each step power of a step (step 5) and a step of cooling (step 6) in which the temperature is raised to a temperature range in which the crosslinking reaction proceeds (step 5) and a step of cooling (step 6). The method for manufacturing a solar cell module according to any of the above.

 [20] A solar cell module having a sealing resin layer between the light-receiving surface side transparent plate and the back plate, wherein the solar cell is sealed in the sealing resin layer, wherein the module is fixed. Metal fittings are inserted into through holes formed in either the light-receiving surface-side transparent plate or the back plate, and the head-side end of the metal fitting is disposed on the sealing resin layer side. A solar cell module, wherein an opposite end of the metal fitting protrudes outward.

 21. The solar cell module according to claim 20, wherein the solar cell module does not have a spacer on the periphery of the sealing resin layer.

 22. The solar cell module according to claim 20, wherein the through hole is a countersink, and the head of the metal fitting is fitted into the countersink.