Abstract:
Disclosed is a solar cell apparatus wherein contamination of solar cells is suppressed and a power generation quantity of the solar cells is maintained for a long period of time, even if the solar cell apparatus is disposed outside. The apparatus is provided with: a light transmitting plastic material; a light transmitting back sheet; a plurality of bifacial solar cells that are electrically connected to each other by means of interconnectors; and a transparent filled resin that surrounds the solar cells. The light transmitting plastic material has a curved surface, and capable of constituting a hermetically closed space by being fixed to a disposition region of a body having the solar cell apparatus disposed thereon, and the light transmitting back sheet, the solar cells, and the transparent filled resin are disposed in the hermetically closed space.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a solar cell device including a translucent plastic material having a curved surface, and a manufacturing method thereof. 
       BACKGROUND ART 
       [0002]    Recently, solar cells have attracted much interest as clean energy sources. In particular, silicon solar cells, which have higher power generation efficiency, have been taken into consideration as the most potential power for high-end markets for housing, automobiles, and the like in terms of various installation methods and construction sites. A solar cell typically has solar cell units and a translucent member, and light having passed through the translucent member enters the solar cell unit. 
         [0003]    Most of mainstream solar cell devices currently provided have a flat-shaped translucent member. That is, as illustrated in  FIG. 15 , planar stack  6  of a solar cell device including solar cell units  2  is fixed to a fixing target with frame bodies  7  provided at each of the both sides of planar stack  6  (see PTL 1). 
         [0004]    On the other hand, a solar cell device in which a translucent member has a curved surface has also been proposed (PTL 1). Solar cell device  11  illustrated in  FIG. 14  has solar cell units  2  and translucent plastic material  12  having curved surfaces at both lateral end portions, and is fixed to a fixing target with frame portions  14  at both the lateral end portions. When the solar cell device illustrated in  FIG. 14  is tried to be fixed to an automobile roof, a tile-integrated or building material-integrated house, a ship, and the like, a gap occurs between a mounting portion of the solar cell device and a portion to be installed, making it difficult to bring it into close contact with the portion to be installed. As a result, wind and rain sometimes enter a space occurring between the mounting portion of the solar cell device and the fixing target. In addition, there occurs a useless space. Further, there is also a problem of impaired outer appearance. 
         [0005]    Thus, the translucent member of the solar cell device is sometimes required to have a curved surface structure corresponding to the curved surface shape of a portion to be operated such as the automobile roof. However, the solar cell device including the translucent member having the curved surface structure lacks flexural strength at a location with smaller curvature radius of the translucent member, causing the problem of cracks or fractures easily occurring in the solar cell unit. 
         [0006]    On the other hand, the translucent member of the currently provided solar cell device is often a glass substrate. Therefore, the weight of the solar cell device for an automobile roof is at least 30 kg. As a result, there occurs a problem of increasing fuel consumption of an automobile having the solar cell device mounted on the automobile roof. To solve this problem, there is also an attempt to provide a solar cell device having structural strength that can resist wind pressure using lightweight translucent plastic material  12  made of polycarbonate in place of the glass substrate (PTL 1). 
       CITATION LIST 
     Patent Literature 
       [0000]    
       
         PTL 1 
         Japanese Patent Application Laid-Open No. 10-229215 
       
     
       SUMMARY OF INVENTION 
     Technical Problem 
       [0009]    PTL 1 discloses that a solar cell device provided with translucent plastic material  12  having a curved surface as illustrated in  FIG. 14  has a similar strength to that of the solar cell device using a translucent member of tempered glass, thereby overcoming the problem of solar cell devices being destroyed by wind pressure. 
         [0010]    The solar cell device illustrated in  FIG. 14  is fixed to a fixing target with frame portions  14  provided at a part (two lateral sides) of the outer periphery of a sealing area for solar cell units  2 . However, frame portions  14  are provided only at a part of the outer periphery of the sealing area for solar cell units  2 , and thus the structural strength of the solar cell device fixed to the fixing target is not sufficient. In addition, there is a problem of wind and rain or dust blowing into the solar cell device through portions not fixed to the fixing target (upper side and lower side). Therefore, the solar cell device disclosed in PTL 1 cannot be used as a member (such as a roof) for closing an automobile interior or a house interior airtight. 
         [0011]    In addition, the solar cell device is preferably disposed such that the incidence angle of sunlight relative to its light-receiving surface is right angle, in order to increase the power generation amount. However, the solar cell device disclosed in PTL 1 is required to adjust the angle of the light-receiving surface of the solar cell device using a rack or a frame body for fixing the solar cell device to the fixing target. When the solar cell device disclosed in PTL 1 is installed on a flat place such as a deck roof of factories, or the like, or the ground, for example, it is required that the angle of the light-receiving surface of the solar cell device should be adjusted using a rack or a frame body depending on the angle of sunlight. 
         [0012]    Thus, the present invention provides a solar cell device that maintains the amount of power generation of a solar cell unit for a long period of time by preventing the solar cell unit from being stained even being installed outdoors. 
       Solution to Problem 
       [0013]    In view of the above-described conventional problems, in a solar cell device of the present invention including a solar cell unit and a translucent plastic material, an airtight space is formed by the translucent plastic material and a fixing target, to enable the double-sided light-receiving solar cell unit to be disposed in the airtight space. The airtight space is configured not to allow stain due to wind and rain or dust to enter the airtight space. In addition, light reflectivity is preferably imparted to the surface of an installing area of the fixing target where the airtight space is formed. 
         [0014]    A first aspect of the present invention is to provide a solar cell device including a translucent plastic material, a translucent back sheet, a plurality of double-sided light-receiving solar cell units being disposed between a sealing area of the translucent plastic material and the translucent back sheet and being electrically connected with each other through an interconnector, and a transparent filling resin surrounding the plurality of solar cell units. The translucent plastic material has a dome-shaped curved surface, and has a frame body being molded at a bottom surface of the dome-shaped translucent plastic material. The frame body is fixed to an installing area of a fixing target on which the solar cell device is installed, to thereby enable the translucent plastic material to form an airtight space. The translucent back sheet, the solar cell unit, and the transparent filling resin are disposed in the airtight space. 
         [0015]    The surface of the installing area of the fixing target where the airtight space is formed preferably has light reflectivity. 
         [0016]    It is preferable that the fixing target is an automobile body including an automobile roof, and that the solar cell device is fixed to the automobile body of the automobile roof, to thereby prevent wind and rain from the outside from entering the vehicle. 
         [0017]    Further, it is preferable that the fixing target is an automobile body having a roof including a sliding plate that takes light into the automobile, and that a light reflector is provided on a surface, facing the solar cell device, of the sliding plate. 
         [0018]    A second aspect of the present invention is to provide a method of manufacturing a solar cell device, the method including: preparing a stack including a translucent plastic plate, a translucent back sheet, a plurality of double-sided light-receiving solar cell units being disposed between a sealing area of the translucent plastic material and the translucent back sheet and being electrically connected with each other through an interconnector, and a transparent filling resin surrounding the plurality of solar cell units; and pressing the stack against a molding die provided with a vacuum hole and bending the translucent plastic plate to afford the translucent plastic material. 
         [0019]    In the above-described manufacturing method, the stack is preferably prepared by pressurizing and laminating a stacked product of a translucent plastic plate, a translucent back sheet, a plurality of double-sided light-receiving solar cell units being disposed between a sealing area of the translucent plastic material and the translucent back sheet and being electrically connected with each other through an interconnector, a transparent filling resin surrounding the plurality of solar cell units, and an elastic resin sheet. 
       Advantageous Effects of Invention 
       [0020]    As described above, in the solar cell device of the present invention, an airtight space is formed by the translucent plastic material and the fixing target, to allow the double-sided light-receiving solar cell unit to be placed in the airtight space. Therefore, the solar cell unit placed in the airtight space is not easily stained even when the solar cell device is installed outdoors. In addition, since the translucent plastic material and the fixing target can form the airtight space, a rack or a frame body to be used exclusively for fixing the solar cell device is not required. 
         [0021]    In addition, the light reflector provided on the surface of the installing area of the fixing target where an airtight space is formed enables light reflected at the surface of the installing area of the fixing target to enter the double-sided light-receiving solar cell unit, thereby allowing the amount of power generation by the solar cell unit to be increased. Further, since the airtight space is configured not to allow the stain due to wind and rain or dust to enter the airtight space, light reflectivity is not decreased. Therefore, it is possible to limit the decrease in the amount of power generation by the solar cell unit. 
         [0022]    Thus, the solar cell device of the present invention allows the amount of power generation of the solar cell unit to be higher and the power generation efficiency per unit area to be higher, and is configured not to allow the stain due to wind and rain or dust to enter the airtight space in which the solar cell unit is disposed. Therefore, the solar cell device of the present invention can be used as a member for closing the interior of an automobile or the interior of a house airtight. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0023]      FIG. 1A  is a top view of a solar cell device of Embodiment 1; 
           [0024]      FIG. 1B  is a sectional view of the solar cell device of Embodiment 1; 
           [0025]      FIG. 1C  is a sectional view of the solar cell device of Embodiment 1; 
           [0026]      FIG. 2A  illustrates a manufacturing flow of the solar cell device of Embodiment 1; 
           [0027]      FIG. 2B  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0028]      FIG. 2C  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0029]      FIG. 3A  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0030]      FIG. 3B  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0031]      FIG. 3C  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0032]      FIG. 4A  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0033]      FIG. 4B  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0034]      FIG. 5A  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0035]      FIG. 5B  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0036]      FIG. 6  illustrates the manufacturing flow of the solar cell device of Embodiment 1; 
           [0037]      FIG. 7  is a sectional view of a solar cell device of Embodiment 2; 
           [0038]      FIG. 8  is a sectional view of a solar cell device of Embodiment 3; 
           [0039]      FIG. 9  illustrates a manufacturing flow of the solar cell device of Embodiment 3; 
           [0040]      FIG. 10  illustrates the manufacturing flow of the solar cell device of Embodiment 3; 
           [0041]      FIG. 11  is a sectional view of a solar cell device of Embodiment 4; 
           [0042]      FIG. 12  is a sectional view of a solar cell device of Embodiment 5; 
           [0043]      FIG. 13  is a detailed sectional view of a double-sided solar cell device; 
           [0044]      FIG. 14  is a sectional view of a conventional solar cell device; and 
           [0045]      FIG. 15  is a perspective view of the conventional solar cell device. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0046]    Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. 
       Embodiment 1 
       [0047]      FIGS. 1A to 1C  are a top view ( FIG. 1A ) and sectional views ( FIG. 1B  (A-A sectional view in  FIG. 1A ) and  FIG. 1C  (B-B sectional view in  FIG. 1A )) of the solar cell device of Embodiment 1. Solar cell device  11  illustrated in  FIGS. 1A to 1C  includes a plurality of double-sided light-receiving solar cell units  22 . Solar cell units  22  adjacent to each other are electrically connected in series by electrically connecting a light-receiving electrode on the front side of one solar cell unit  22  to a light-receiving electrode on the rear side of the other solar cell unit  22  through interconnector  1 . In addition, solar cell device  11  illustrated in  FIGS. 1A to 1C  includes transparent filling resin  3  that surrounds a plurality of solar cell units  22 . 
         [0048]    Further, solar cell device  11  illustrated in  FIGS. 1A to 1C  includes translucent plastic material  12  disposed on the light-receiving surface side of a plurality of solar cell units  22  that perform double-sided power generation, with transparent filling resin  3  interposed therebetween, and translucent back sheet  25  disposed on the rear surface side through transparent filling resin  3 , and these components are integrated together. 
         [0049]      FIG. 13  illustrates an example of the stacking configuration in sealing area  15  for the solar cell device of Embodiment 1. As illustrated in  FIG. 13 , the solar cell device of Embodiment 1 includes, from the light-receiving surface side, translucent plastic material  12 , transparent filling resin  3 , solar cell unit  22  that performs double-sided power generation, transparent filling resin  3 , and translucent back sheet  25 . A pair of transparent filling resins  3  surround solar cell unit  22  that performs double-sided power generation. Further, close contact layer  46  is formed on a surface, facing solar cell unit  22 , of translucent plastic material  12 , and waterproof film  45  is formed on the front layer, being exposed to the outside air, of translucent plastic material  12 . 
         [0050]    Waterproof film  45  has waterproofness, humidity resistance, hardness-enhancing capacity, UV-shielding capacity, and the like. Examples of the material for waterproof film  45  include organic materials excellent in translucency, such as acrylic materials and fluoric materials, and thin metal films such as a gold film. The thin metal films sometimes may have slightly lowered translucency. 
         [0051]    The material for translucent plastic material  12  is made of a resin that can secure the amount of light transmission necessary for allowing double-sided light-receiving solar cell unit  22  to generate power; translucent plastic material  12  may include polycarbonate or acrylic resin (PMMA). An antireflective film may be formed on the surface of translucent plastic material  12  (interface with waterproof film  45 ). The thickness of translucent plastic material  12  in solar cell device  11  of Embodiment 1 is 5 mm. 
         [0052]    Further, a gas barrier layer having a steam permeability of 0.2 g/m 2 ·day or less is preferably formed on the front surface or the rear surface, or on both surfaces of translucent plastic material  12 . This is because translucent plastic material  12  has higher moisture permeability and water absorption rate than glass substrates. Formation of a gas barrier layer having a steam permeability of 0.2 g/m 2 ·day or less can inhibit transparent filling resin  3  from undergoing hydrolysis due to moisture having permeated translucent plastic material  12 . The hydrolysis of transparent filling resin  3  causes the adhesion between translucent plastic material  12  and transparent filling resin  3  to be reduced. In addition, the moisture having permeated translucent plastic material  12  and having entered the interface with transparent filling resin  3  undergoes volume change due to the temperature change when using solar cell device  11 , causing translucent plastic material  12  and transparent filling resin  3  to be exfoliated from each other, and causing the exfoliated portion to be further expanded. Further, the moisture having permeated translucent plastic material  12  and transparent filling resin  3  sometimes deteriorates the surface of the solar cell unit or a junction between the solar cell units. 
         [0053]    Double-sided light-receiving solar cell unit  22  is a solar cell unit that converts sunlight incident on both surfaces into electricity, and is represented by HIT (registered trademark, Panasonic Corporation), or the like. Double-sided light-receiving solar cell unit  22  has, for example, a structure in which a P amorphous layer is provided on one surface of N-type monocrystalline silicon, and an N amorphous layer is provided on the other surface. The thickness of solar cell unit  22  that performs double-sided power generation in solar cell device  11  of Embodiment 1 is 130 μm. 
         [0054]    Solar cell unit  22  in solar cell device  11  of Embodiment 1 includes a p-type monocrystalline silicon substrate having a resistivity of 1 Ω·cm and a thickness of 350 μm. A texture structure (not illustrated) is formed on both surfaces of the p-type monocrystalline silicon substrate. The texture structure has such an irregular shape as to reduce light reflection on its surface. The texture structure is formed, for example, by wet etching the surface of the silicon substrate with an alkali solution. 
         [0055]    Solar cell unit  22  may include a silicon substrate such as a polycrystalline silicon substrate in place of the monocrystalline silicon substrate. A texture structure can be formed on the surface of the polycrystalline silicon substrate using an acid solution. Further, solar cell unit  22  may include a compound-based semiconductor such as GaAs or Ge semiconductor in place of the silicon substrate, thereby allowing solar cell unit  22  to be a compound-based solar cell. 
         [0056]    An n-type layer is formed on one surface of the p-type monocrystalline silicon substrate included in solar cell unit  22 . The n-type layer may have a thickness that is the depth of up to about 1 μm from one surface of the p-type monocrystalline silicon substrate. The n-type layer is formed by exposing one surface of the p-type monocrystalline silicon substrate to a phosphorus oxychloride gas (POCl 3  gas) at 900° C. followed by thermal diffusion of P (phosphorus). Phosphorus glass (PSG) is sometimes used in place of the phosphorus oxychloride gas. 
         [0057]    Solar cell unit  22  has an antireflective film formed on a light-receiving surface of the p-type monocrystalline silicon substrate. The antireflective film is made of SiNx, for example, and may be formed by plasma CVD method. Further, solar cell unit  22  has a finger-shaped Ag electrode disposed on the antireflective film. The Ag electrode is formed by printing an Ag paste followed by heat treatment. The heat treatment allows Ag to penetrate into SiNx that is an antireflective film, and allows Ag to contact the surface of the n-type layer. Such heat treatment is referred to as fire-through (penetration firing). 
         [0058]    A rear surface electrode made of Al is disposed on the other surface (rear surface) of the p-type monocrystalline silicon substrate included in solar cell unit  22 . The rear surface electrode made of Al is formed by screen printing of an Al paste on the rear surface of the p-type monocrystalline silicon substrate. Further, heat treatment at about 700° C. for a short period of time allows Al to be thermally diffused in the silicon substrate. Thus, a p-type layer in which Al is highly doped is also formed together. 
         [0059]    Through these steps, solar cell unit  22  can be obtained that has a double-sided amorphous layer in the silicon substrate and Ag interconnection on the silicon substrate, and that performs double-sided power generation. 
         [0060]    Transparent filling resin  3  is a resin layer surrounding solar cell unit  22 ; typically a pair of transparent filling resins  3  interpose solar cell unit  22  between the upper one and the lower one of the pair of transparent filling resins  3 . The thickness of each of transparent filling resins  3  in solar cell device  11  of Embodiment 1 is 0.6 mm. 
         [0061]    Transparent filling resin  3  is mainly composed of ethylene, and includes a copolymer of ethylene and a monomer that is polymerizable with ethylene. Examples of the copolymer include copolymers of ethylene and vinyl esters such as vinyl acetate, and vinyl propionate; copolymers of ethylene and unsaturated carboxylic acids such as methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, and methyl methacrylate, or ionomers thereof; copolymers of ethylene and α-olefins such as propylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene; and mixtures thereof. More typically, examples of transparent filling resin  3  include ethylene vinyl acetate copolymer resin (EVA). 
         [0062]    Transparent filling resin  3  may be a cross-linked product of a resin composition including the copolymer and a cross-linking agent. The cross-linking agent is, for example, an organic peroxide, and preferably has a decomposition temperature (temperature at which half-life period is 1 hour) of 90° C. to 180° C. Examples of the organic peroxide include t-butylperoxyisopropyl carbonate, t-butylperoxy acetate, t-butylperoxy benzoate, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3,1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, methylethylketone peroxide, 2,5-dimethylhexyl-2,5-bisperoxy benzoate, t-butyl hydroperoxide, p-menthane hydroperoxide, benzoyl peroxide, p-chlorobenzoyl peroxide, t-butylperoxy isobutyrate, hydroxyheptyl peroxide, and dicyclohexanone peroxide. 
         [0063]    In addition, transparent filling resin  3  may be a cross-linked product of a resin composition including a cross-linking auxiliary together with the copolymer and the cross-linking agent. The cross-linking auxiliary enables a cross-linking reaction to easily proceed. Examples of the cross-linking auxiliary include triallyl cyanurate, triallyl isocyanurate, ethyleneglycol dimethacrylate, trimethylolpropane trimethacrylate divinylbenzene, and diallyl phthalate. 
         [0064]    Further, transparent filling resin  3  may be a reactant of a resin composition including the copolymer and an adhesion prompter. The adhesion prompter enhances the adhesiveness between translucent plastic material  12  and transparent filling resin  3 . The adhesion prompter is a silane coupling agent, or the like. Examples of the silane coupling agent include vinyl triethoxysilane, vinyl tris(β-methoxy-ethoxy)silane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane. 
         [0065]    A terminal group of the silane coupling agent included in transparent filling resin  3  and a hydroxyl group (OH group) on the surface of translucent plastic material  12  undergo a hydrolysis•polymerization reaction, thereby bringing about adhesion between translucent plastic material  12  and transparent filling resin  3 . 
         [0066]    When a silane coupling agent is not added to transparent filling resin  3 , adhesion between transparent filling resin  3  and translucent plastic material  12 , or adhesion between transparent filling resin  3  and translucent back sheet  25  is decreased, which may sometimes causes exfoliation. Therefore, problems may occur, in which panel strength at the time when transporting and using the solar cell device cannot be secured, outer appearance is impaired, or the characteristics of electricity generated by the solar cell device are decreased. 
         [0067]    Transparent filling resin  3  may be further mixed with various other additives. Examples of the additives include ultraviolet absorbers, light stabilizers and antioxidants, for preventing the deterioration due to ultraviolet rays in sunlight. Examples of the ultraviolet absorbers include benzophenone-based ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone, 2-2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2-carboxybenzophenone, and 2-hydroxy-4-n-octoxybenzophenone; benzotriazole-based ultraviolet absorbers such as 2-(2-hydroxy-3,5-di-t-butylphenyl)benzotriazole, 2-(2-hydroxy-5-methylphenyl)benzotriazole, and 2-(2-hydroxy-5-t-octylphenyl)benzotriazole; and salicylate ester-based ultraviolet absorbers such as phenyl salicylate, and p-octylphenyl salicylate. Examples of the light stabilizers include hindered amine-based light stabilizers. Examples of the antioxidants include hindered phenol-based and phosphite-based antioxidants. 
         [0068]    Examples of translucent back sheet  25  include PET films, polyester films, glass cloth transparent films, acrylic films, and vinyl chloride films. In addition, translucent back sheet  25  may be a stacked film in which transparent conductive materials such as ITO and ZnO are stacked on these films. The thickness of translucent back sheet  25  in the solar cell device of Embodiment 1 is 0.05 mm. 
         [0069]    As illustrated in  FIGS. 1A to 1C , solar cell device  11  of Embodiment 1 forms airtight space  20  with translucent plastic material  12  and fixing target  24 . That is, translucent plastic material  12  has a dome-shaped curved surface structure, and thus can form airtight space  20 . 
         [0070]    In addition, translucent plastic material  12  has frame portion  14  on the bottom surface of the dome. Translucent plastic material  12  is fixed to installing area  19  of fixing target  24  via frame portion  14 . In order to fix translucent plastic material  12  to fixing target  24 , frame portion  14  may be fixed to fixing target  24  using fixing screw  21  or an adhesive. Frame portion  14  of translucent plastic material  12  preferably surrounds the four sides of installing area  19 . This is because the airtightness of airtight space  20  should be enhanced. 
         [0071]    Thus, there is no need for an aluminum frame as the frame body for fixing the solar cell device, or for a rack to be used exclusively for fixing the solar cell device to the ground or a roof, since frame portion  14  of translucent plastic material  12  is fixed to fixing target  24 . 
         [0072]    While fixing target  24  for fixing solar cell device  11  is not particularly limited, fixing target  24  may be the ground, a concrete member, a building, an automobile roof, or the like. 
         [0073]    Double-sided light-receiving solar cell unit  22  is disposed on the inner surface of translucent plastic material  12  of airtight space  20 . An area in which solar cell unit  22  is disposed is referred to as sealing area  15 . Solar cell unit  22  is surrounded by transparent filling resin  3 . Solar cell unit  22  and transparent filling resin  3  are disposed between sealing area  15  of translucent plastic material  12  and translucent back sheet  25 . Enhancement of airtightness of airtight space  20  can prevent solar cell unit  22  provided inside airtight space  20  from being stained by wind and rain or dust, when the solar cell device is installed outdoors. 
         [0074]    Light reflector  23  is preferably provided on the surface of installing area  19  of fixing target  24  where airtight space  20  is formed. Thus, disposing light reflector  23  inside airtight space  20  imparts light reflectivity to the surface of installing area  19 . Sunlight reflected by light reflector  23  enters double-sided light-receiving solar cell unit  22  to undergo photoelectric conversion. In addition, light reflector  23  is disposed inside the airtight space formed by translucent plastic material  12 , and thus is prevented from being stained with wind and rain or dust from the external environment, allowing light reflectivity to be maintained. As a result, the amount of power generation of solar cell unit  22  can be maintained for a long period of time. 
         [0075]    The surface of sealing area  15  of translucent plastic material  12 , fixed to fixing target  24 , of the solar cell device of Embodiment 1 is not parallel to the surface of fixing target  24  (see  FIG. 1B ). Specifically, the surface of sealing area  15  of translucent plastic material  12  is preferably set so as to be at right angle relative to the incident angle of sunlight, in order that the amount of power generation by solar cell unit  22  reaches the maximum. As for the angle of the surface of sealing area  15 , the shape of a molding die of translucent plastic material  12  may be adjusted. 
         [0076]    Thus, since translucent plastic material  12  can form an airtight space together with the fixing target, solar cell device  11  of Embodiment 1 can close an automobile interior or a house interior (inhibit wind and rain or dust from blowing into the interiors) airtight even when being installed on the roof of the automobile or the house. Further, appropriate setting of the shape of the translucent plastic material enables the angle of the surface of the sealing area to be adjusted. Therefore, it becomes possible to obtain the maximum amount of power generation of the solar cell unit by setting the shape of the translucent plastic material such that the incident angle of sunlight is orthogonal to the surface of the sealing area. 
         [0077]    With the above-described configurations, the solar cell device  11  of Embodiment 1 can protect solar cell unit  22  from wind and rain or from dusty outside air, enabling a highly reliable solar cell device to be provided. 
         [0078]    [Method of Manufacturing Solar Cell Device] 
         [0079]    The manufacturing flows of the solar cell device of Embodiment 1 will be described with reference to  FIGS. 2A to 2C ,  3 A to  3 C,  4 A,  4 B,  5 A,  5 B; and  6 . 
         [0080]    As illustrated in  FIG. 2A , tabular translucent plastic material  12  is prepared. Tabular translucent plastic material  12  is molded to form translucent plastic material  12  having a curved surface. Translucent plastic material  12  is required to have higher light transmissivity; the average light transmittance of the entire wavelength of sunlight is preferably 95 to 98%, although light in UV wavelength range may be absorbed depending on material properties. 
         [0081]    Next, as illustrated in  FIG. 2B , a film made of transparent filling resin  3  cut into a predetermined size is pasted on translucent plastic material  12  at normal temperature. The thickness of the film made of transparent filling resin  3  is appropriately set depending on the thickness of solar cell unit  22 , the curved surface shape of translucent plastic material  12 , or the like; the thickness of the film is set within a range of 0.2 to 2 mm, for example, and is 0.6 mm in the present embodiment 1. In addition, the film made of transparent filling resin  3  either may be one film, or may be a stack of two or more films; further the number of film may be different from area to area. 
         [0082]    As illustrated in  FIG. 2C , a plurality of solar cell units  22  are connected through interconnectors  1 . That is, a front surface electrode of one solar cell unit  22  is connected to a rear surface electrode of the other solar cell unit  22  through interconnector  1 . Interconnector  1  is joined to the front surface electrode or the rear surface electrode of solar cell unit  22  by joining material  26 . 
         [0083]    In order to extract power generated by solar cell unit  22 , electrical conduction and mechanical joining strength resistant to a temperature cycle and a high temperature and high humidity testing are required between the front and rear surface electrodes of solar cell unit  22  and interconnector  1 . Therefore, as joining material  26 , in general, a soldering material such as SnPb, SnAgCu and SnAgBi, an anisotropic conductive film referred to as ACF, an adhering paste having an epoxy as a main component referred to as a non-anisotropic conductive paste (NCP), or the like is used. 
         [0084]    In order to join interconnector  1  to the front and rear surface electrodes of solar cell unit  22  using joining material  26 , 1) joining material  26  is supplied to the front and rear surface electrodes of solar cell unit  22  by means of printing, application, pasting, or the like; 2) interconnector  1  is positioned on the front and rear surface electrodes of solar cell unit  22 ; and 3) interconnector  1  is pressurized against both surfaces of solar cell unit  22  concurrently to be bonded to both the surfaces of solar cell unit  22  using a heating and pressurizing head to allow joining material  26  to be melted and then hardened. In the general condition for pressure bonding, pressure-bonding is performed at 170° C. to 250° C. for 5 to 10 seconds, for example. Joining is performed for each of solar cell units  22  to electrically connect a plurality of solar cell units  22  in series. 
         [0085]    As illustrated in  FIG. 3A , in the next step, the plurality of solar cell units  22  connected through interconnector  1  are positioned on transparent filling resin  3 . Positioning fiducial mark is preferably provided in advance at a predetermined position of transparent plastic material  12 . Using the fiducial mark as a reference, the plurality of solar cell units  22  can be disposed collectively on transparent filling resin  3 . Since the plurality of solar cell units  22  are collectively mounted, damage to solar cell units  22  and defects such as disconnection of interconnector  1  should be noted. 
         [0086]    Next, as illustrated in  FIG. 3B , transparent filling resin  3  to make a pair is mounted on the plurality of solar cell units  22  while positioning transparent filling resins  3 . Transparent filling resin  3  is cut, from which lead-out portion  1   a  of interconnector  1  is led to the outside. 
         [0087]    Next, as illustrated in  FIG. 3C , translucent back sheet  25  is mounted on transparent filling resin  3  on the plurality of solar cell units  22  while positioning translucent back sheet  25 . Translucent back sheet  25  is cut, from which lead-out portion  1   a  part of interconnector  1  is led to the outside. Thus, a stacked product is afforded, in which translucent plastic material  12 , a pair of transparent filling resin  3 , solar cell units  22 , and translucent back sheet  25  are stacked. 
         [0088]    As illustrated in  FIG. 4A , in the next step, the stacked product afforded in the step illustrated in  FIG. 3C  is laminated to afford an integrated stacked product. In the laminating step illustrated in  FIG. 4A , pressure is applied to the stacked product afforded in the step illustrated in  FIG. 3C  through elastic material sheet  44 . Applying pressure to the stacked product through elastic material sheet  44  makes it possible to apply pressure to translucent plastic material  12  evenly. 
         [0089]    The antireflective film and gas barrier layer formed on translucent plastic material  12  sometimes have moisture absorbed inside. The absorbed moisture is preferably removed from translucent plastic material  12  in order that the moisture should not undesirably occur as a bubble due to heating in the laminating step. In order to remove the moisture from translucent plastic material  12 , the stack may be dried at 120° C. for 5 hours in advance, for example. It is preferable to store the stack together with silica gel in an airtight state and to use the stack in the laminating step immediately after opening the sealing. 
         [0090]    In the laminating step illustrated in  FIG. 4A , the above-mentioned stacked product is heated using heating metal plate  31  at the lower portion and heater  27  at the upper portion to a temperature equal to or lower than the glass transition temperature of translucent plastic material  12  (e.g., 150° C.). Thus, transparent filling resin  3  of the stacked product is sufficiently melted. At that time, the internal pressures of vacuum pressure furnace  28  and vacuum furnace  29  are lowered to 130 Pa or lower as a criterion, in order that a cross-linking reaction of transparent filling resin  3  should not be initiated. Specifically, vacuum drawing steps inside vacuum pressure furnace  28  and vacuum furnace  29  are performed for 10 to 30 minutes. 
         [0091]    In the laminating step, elastic material sheet  44  contacts translucent back sheet  25 . However, the internal pressure of vacuum pressure furnace  28  and the internal pressure of vacuum furnace  29  are controlled to be identical, and thus translucent back sheet  25  is hardly pressurized by elastic material sheet  44 . Therefore, the cross-linking reaction is not initiated. 
         [0092]    Next, while maintaining the vacuum inside vacuum furnace  29 , air is put into vacuum pressure furnace  28  to adjust the internal pressure of vacuum pressure furnace  28  to a range of 0.5 to the maximum of 2 atmospheres. Consequently, elastic material sheet  44  pressurizes translucent back sheet  25  to allow the cross-linking reaction of transparent filling resin  3  to proceed sufficiently. The time for pressurization is 5 to 15 minutes, for example. In addition, in order to allow the cross-linking reaction of transparent filling resin  3  to proceed sufficiently in a short period of time, it is also possible to put hot air (up to the maximum of 200° C.) into vacuum pressure furnace  28  instead of normal temperature air. 
         [0093]    With the above-described laminating step, the cross-linking reaction of transparent filling resin  3  is initiated, and translucent plastic material  12 , solar cell unit  22  and translucent back sheet  25  are brought into close contact with one another and are integrated to form a stack. Subsequently, the stack undergoes curing step at about 100° C. to 150° C. for about 30 to 90 minutes so as to complete the cross-linking reaction of transparent filling resin  3 . 
         [0094]    As illustrated in  FIG. 4B , in the next step, terminal box  32  is attached to translucent back sheet  25 . The inside of terminal box  32  is typically subjected to insulation treatment and waterproof and moisture-proof treatments using silicone grease. The power generated by solar cell unit  22  is electrically led out through interconnector  1 , and led out to the outside at lead-out portion  1   a . Lead-out portion  1   a  is electrically connected to terminal box  32  using soldering or a welding method. 
         [0095]    Interconnector  1  is connected to the external wiring at terminal box  32 . For example, solar cell devices  11  ( FIGS. 1A  to C) are electrically connected via terminal box  32 , and a plurality of electrically connected solar cell devices  11  form a solar cell system. 
         [0096]    As illustrated in  FIGS. 5A and 5B , in the next step, translucent plastic material  12  of the stack afforded in the step illustrated in  FIG. 4B  is molded into a shape having a predetermined curved surface, and frame portion  14  (see  FIGS. 1A  to C) is molded. This step is referred to as a vacuum molding step. 
         [0097]    In the first step of the vacuum molding step, the stack afforded in the step illustrated in  FIG. 4B  is subjected to baking treatment in order to remove the moisture inside translucent plastic material  12 . The baking temperature is set to be equal to or lower than the glass transition temperature of the material for translucent plastic material  12 , typically to 100° C. to 150° C. While the time for baking translucent plastic material  12  having been stored under high humidity environment is not particularly limited, the baking time is set within “square value of thickness (mm)×1 hour.” For example, when the thickness of translucent plastic material  12  is 5 mm, the time of within 25 (=5×5) hours is set as a criterion. When the thickness of translucent plastic material  12  having been stored properly under low humidity environment is 5 mm, the baking time may be 5 to 10 hours. 
         [0098]    In the second step of the vacuum molding step, the peripheral portion of translucent plastic material  12  immediately after taken out from the bake furnace is interposed by fixing frame  33  of the vacuum molding machine to fix the peripheral portion. At that time, solar cell unit  22  is set so as to face molding die  34  (see  FIG. 5A ). 
         [0099]    In the third step of the vacuum molding step, the temperatures of upper heater  27   a  and lower heater  27   d  are raised to heat translucent plastic material  12 . The temperatures of upper heater  27   a  and lower heater  27   d  are set, for example, within a range of 300° C. to 500° C. such that the temperature of translucent plastic material  12  is within a range of 150° C. to 200° C. that is equal to or more than the glass transition temperature (Tg) of the material for translucent plastic material  12 , thereby making it easier to mold translucent plastic material  12  into a desired shape. 
         [0100]    Concurrently, the temperatures of heater  27   b  provided inside molding die  34  and of heater  27   c  of molding die mounting base  36  are also raised (see  FIG. 5B ). The temperatures of heaters  27   b  and  27   c  are preferably temperatures at which translucent plastic material  12  is easily transformed, and at which translucent plastic material  12  is curable by cooling. 
         [0101]    In the fourth step of the vacuum molding step, the temperature of translucent plastic material  12  reaches a predetermined temperature (e.g., is allowed to reach 150° C. to 180° C. over about 1 to 3 minutes), and subsequently a member composing lower heater  27   d  is removed, such that translucent plastic material  12  and fixing frame  33  can be moved up to molding die  34  (such that lower heater  27   d  should not interfere with the movement). 
         [0102]    As illustrated in  FIG. 6 , translucent plastic material  12  is molded into a desired shape by vacuum molding. Fixing frame  33  is allowed to descend to bring translucent plastic material  12  integrated with solar cell unit  22  into contact with vertex portion  34   a  (see  FIG. 5B ) of molding die  34 . Further, fixing frame  33  is continuously allowed to descend. When fixing frame  33  contacts vertex portion  34   a , vacuum pumps connected to a plurality of vacuum holes  35  suck air from vacuum holes  35  on the surface of molding die  34 . 
         [0103]    Translucent plastic material  12  softened by heating is allowed to descend by fixing frame  33  to contact molding die  34 . Since air is sucked from vacuum holes  35 , softened translucent plastic material  12  is brought into close contact with molding die  34 . As a result, the shape of molding die  34  is transferred to translucent plastic material  12 . 
         [0104]    The heat of translucent plastic material  12  having contacted molding die  34  is transmitted to molding die  34 . As a result, translucent plastic material  12  is hardened due to temperature decrease. In order to lower the temperature of translucent plastic material  12  efficiently, air may be blown from the outside using a fan. 
         [0105]    After sufficient hardening is confirmed when the temperature of translucent plastic material  12  is lowered to 70° C. or lower, air is blown through vacuum holes  35 , so that translucent plastic material  12  is released from molding die  34  by the air blow. Further, translucent plastic material  12  is allowed to ascend by fixing frame  33  to separate translucent plastic material  12  from molding die  34 . 
         [0106]    Next, translucent plastic material  12  fixed by fixing frame  33  is disengaged to remove translucent plastic material  12 . Through the series of vacuum molding, solar cell device  11  of Embodiment 1 ( FIGS. 1A ,  1 B and  1 C) is obtained. The solar cell device of Embodiment 1 includes translucent plastic material  12  having a dome-shaped curved surface, and frame portion  14  on the bottom surface of the dome. While  FIG. 6  illustrates the cross-section of translucent plastic material  12  and the molding device, the solar cell device to be obtained has dome-shaped translucent plastic material  12 , as illustrated in  FIGS. 1A ,  1 B and  1 C. 
         [0107]    Thus, the translucent plastic material of the solar cell device is molded by the method in which the translucent plastic material is pressed against the molding die provided with the vacuum holes, to thereby enable a desired curved surface to be formed on the translucent plastic material. 
       Embodiment 2 
       [0108]      FIG. 7  illustrates a solar cell device of Embodiment 2. The solar cell device of Embodiment 2 has concave curved surface  12   a  being concave with respect to the outer space, at a portion other than sealing area  15  (side surface portion) of translucent plastic material  12  of solar cell unit  22 . Providing concave curved surface  12   a  at the side surface portion enables the area of installing area  19  to be smaller than the area of sealing area  15  for solar cell unit  22 . When the area of installing area  19  is set smaller, it becomes possible to increase ratio of the area of sealing area  15  for solar cell unit  22  to the area of fixing target  24 . As a result, the efficiency in installing the solar cell device is enhanced. 
         [0109]    In addition, providing concave curved surface  12   a  at the side surface portion of translucent plastic material  12  allows the incident angle of sunlight  37  reflected at the surface of fixing target  24  outside installing area  19  into the side surface of translucent plastic material  12  to be larger. Therefore, there is less light reflected at the side surface. As a result, sunlight  37  reflected at the surface of fixing target  24  outside installing area  19  easily enters double-sided light-receiving solar cell unit  22 , thereby enabling the amount of power generation of solar cell unit  22  to be increased. 
       Embodiment 3 
       [0110]      FIG. 8  illustrates a solar cell device of Embodiment 3. The solar cell device of Embodiment 3 has convex curved surface  12   b  being convex with respect to the outer space, at the surface of sealing area  15  of translucent plastic material  12  for solar cell unit  22 . Providing convex curved surface  12   b  at sealing area  15  for solar cell unit  22  allows the rigidity of the solar cell device to be enhanced. In addition, it is also possible to bring the incident angle of sunlight into the surface of sealing area  15  for solar cell unit  22  closer to right angle by adjusting the surface angle of convex curved surface  12   b . Thus, in spite of the change in the altitude of the sun throughout a year and of the movement of the sun throughout a day, it is possible to constantly reduce the reflectance on the surface of sealing area  15  for solar cell unit  22 , and thus to increase the amount of power generation of solar cell unit  22 . 
         [0111]    In the same manner as the solar cell device of Embodiment 1, the solar cell device of Embodiment 3 may be manufactured by 1) laminating translucent back sheet  25 , solar cell unit  22 , translucent plastic material  12  in which an antireflective film and a gas barrier layer are formed, and transparent filling resin  3  represented by EVA to afford an integrated stack (laminating step); and 2) vacuum molding the afforded stack (vacuum molding step). 
         [0112]      FIG. 9  illustrates a laminating step. The solar cell device of Embodiment 3 has convex curved surface  12   b  at sealing area  15  for solar cell unit  22  (see  FIG. 8 ). Therefore, in the laminating step, solar cell unit  22  that performs double-sided power generation is pasted on convex curved surface  12   b  of translucent plastic material  12  having convex curved surface  12   b . This lamination method is an applied method of general “decorative film method.” 
         [0113]    Curved surface laminator  42  has upper frame  42   a  and lower frame  42   b , and concave heating die  43 . Translucent plastic material  12  having a convex curved surface  12   b  is placed on concave heating die  43  inside the device of curved surface laminator  42 . Further, in the same flows as those illustrated in  FIGS. 2A ,  2 B and  2 C, and  3 A,  3 B and  3 C, solar cell unit  22 , transparent filling resin  3 , translucent back sheet  25 , and the like are set on translucent plastic material  12  having a convex curved surface  12   b  placed on heating die  43  to afford a stacked product. 
         [0114]    Next, upper frame  42   a  provided with elastic material sheet  44  is allowed to descend to wrap the afforded stacked product with elastic material sheet  44 . 
         [0115]    Next, the internal pressure of vacuum furnace  29  and the internal pressure of vacuum pressure furnace  28  are set to 130 Pa or lower. Then, the temperatures of heater  27  and heating die  43  are raised to heat transparent filling resin  3  to 40° C. to 80° C. Next, air is put into vacuum pressure furnace  28  to allow the internal pressure to be 0.5 to 2 atmospheres. In such a state, the temperatures of heater  27  and the heating die are raised to 100° C. to 150° C. to heat transparent filling resin  3  while applying pressure to cross-link transparent filling resin  3 . 
         [0116]    Subsequently, the temperatures of heater  27  and heating die  43  are lowered, and the internal pressures of vacuum pressure furnace  28  and vacuum furnace  29  are returned to the atmospheric pressure. Upper frame  42   a  and lower frame  42   b  are opened to thereby produce a stacked product including translucent plastic material  12  having a convex curved surface  12   b.    
         [0117]      FIG. 10  illustrates a vacuum molding step. In the same manner as the vacuum molding step illustrated in  FIG. 6 , translucent plastic material  12  is brought into close contact with molding die  34  to allow translucent plastic material  12  to have a desired curved surface shape. Molding die  34  is composed of a plurality of split dies (split middle dies  34   b  and split outer dies  34   c ), and can be removed by splitting these dies. Therefore, after completion of the vacuum molding step illustrated in  FIG. 10 , split middle dies  34   b  are first moved downward in the drawing to be removed from molding die  34 . Next, split outer dies  34   c  left inside the molded translucent plastic material can be drawn to be removed after having been moved toward the center portion. Thus, translucent plastic material  12  having concave curved surface  12   a  at the side surface can be formed, and molding die  34  can be easily removed. 
         [0118]    When seen from molding die mounting base  36 , for example, molding die  34  is split into nine portions: 3×3=9 in (X:Y) matrix. First, a split die at center portion (0:0) of (X:Y) matrix is removed, and next split dies at (1:0), (−1:0), (0:1) and (0:−1) are removed. Then, split dies at (1:1), (−1:−1), (1:−1) and (−1:1) are removed. 
       Embodiment 4 
       [0119]      FIG. 11  illustrates a solar cell device of Embodiment 4. The solar cell device of Embodiment 4 is an application of the solar cell device of Embodiment 1, and is fixed to vehicle body  38  of an automobile roof as the fixing target. Specifically, frame portion  14  of translucent plastic material  12  of the solar cell device is fixed to vehicle body  38  by adhesive  39 . 
         [0120]    The solar cell device is fixed to vehicle body  38  to thereby allow the interior of the automobile to be closed airtight, so that wind and rain from the outside are prevented from entering the interior of the automobile. In particular, as illustrated in  FIG. 11 , providing vehicle body  38  with vehicle body concave portion  38   a  allows rainwater to flow out of the automobile along vehicle body concave portion  38   a  of vehicle body  38 . 
         [0121]    In addition, the solar cell device of Embodiment 4 may be fixed to vehicle body  38  of the automobile roof having a sunroof (skylight for taking light from the outside into an automobile). The solar cell device of Embodiment 4 may be composed of members that transmit light, other than solar cell unit  22  that performs double-sided power generation and interconnector  1 . Therefore, even when the solar cell device of Embodiment 4 is mounted on vehicle body  38  of the automobile roof, the function of the sunroof can be maintained. 
         [0122]    In addition, when the solar cell device of Embodiment 4 is fixed to vehicle body  38  of the automobile roof having a sunroof, car ceiling plate  40  to be disposed under vehicle body  38  can be provided with sliding plate  41 . When sliding plate  41  is opened, sunlight can be taken into the automobile through the sunroof; when sliding plate  41  is closed, the sunlight is not taken into the automobile as sliding plate  41  shields the sunlight. 
         [0123]    A surface, facing the solar cell device, of sliding plate  41  is preferably provided with light reflector  23 . When sliding plate  41  is closed, sunlight  37  transmitted through the sunroof is reflected at light reflector  23  to be able to enter the rear surface of solar cell unit  22  that performs double-sided power generation. As a result, it is possible to achieve an increase in the amount of power generation of solar cell unit  22  that performs double-sided power generation. 
       Embodiment 5 
       [0124]      FIG. 12  illustrates a solar cell device of Embodiment 5. The solar cell device of Embodiment 5 has prism reflection sheet  50  disposed, on fixing target  24 , around installing area  19  of the solar cell device; however other components are similar to those of the solar cell device of Embodiment 1. Prism reflection sheet  50  is, for example, a prism reflection sheet. The prism reflection sheet has, for example, triangular prisms formed on its surface. 
         [0125]    Examples of prism reflection sheet  50  include white silicone resins, epoxy resins and urethane rubber, white coated polycarbonate and acrylic resin plates, and films coated with a liquid in which highly reflective shell powder is mixed. 
         [0126]    Sunlight  37  having entered prism reflection sheet  50  is reflected toward double-sided light-receiving solar cell unit  22  to enable the power generation amount to be increased. The amount of power generation of double-sided light-receiving solar cell unit  22  can be increased, for example, by 10 to 20%. 
         [0127]    The present application is entitled to and claims the benefit of Japanese Patent Application No. 2013-082309 filed on Apr. 10, 2013, the disclosure of which including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
       INDUSTRIAL APPLICABILITY 
       [0128]    A solar cell device of the present invention includes a translucent plastic material having a dome-shaped curved surface and having a frame being molded at the bottom surface of the dome. Thus, fixing the frame of the translucent plastic material to a fixing target can form an airtight space inside the dome. Therefore, the solar cell unit disposed inside the airtight space can be prevented from being stained by the outer space (due to wind and rain from the outside). In addition, the solar cell device of the present invention is lightweight and has higher rigidity. The solar cell device of the present invention can be used as a solar cell device for general household use, and commercial and automobile uses. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  Interconnector 
           1   a  Lead-out portion 
           2  Solar cell unit 
           3  Transparent filling resin 
           6  Stack 
           7  Frame body 
           11  Solar cell device 
           12  Translucent plastic material 
           12   a  Concave curved surface 
           12   b  Convex curved surface 
           14  Frame portion 
           15  Sealing area 
           19  Installing area 
           20  Airtight space 
           21  Fixing screw 
           22  Solar cell unit 
           23  Light reflector 
           24  Fixing target 
           25  Translucent back sheet 
           26  Joining material 
           27  Heater 
           27   a  Upper heater 
           27   b ,  27   c  Heater 
           27   d  Lower heater 
           28  Vacuum pressure furnace 
           29  Vacuum furnace 
           31  Heating metal plate 
           32  Terminal box 
           33  Fixing frame 
           34  Molding die 
           34   a  Vertex portion 
           34   b  Split middle die 
           34   c  Split outer die 
           35  Vacuum hole 
           36  Molding die mounting base 
           37  Sunlight 
           37   a  Reflected light 
           38  Vehicle body 
           38   a  Vehicle body concave portion 
           39  Adhesive 
           40  Car ceiling plate 
           41  Sliding plate 
           42  Curved surface laminator 
           42   a  Upper frame 
           42   b  Lower frame 
           43  Heating die 
           44  Elastic material sheet 
           45  Waterproof film 
           46  Close contact layer 
           50  Prism reflection sheet