JP2013207291A - Method for sticking protective sheet for photoelectric conversion device, method for manufacturing photoelectric conversion device, and photoelectric conversion device - Google Patents

Abstract

Provided is a method for attaching a protective sheet for a photoelectric conversion device, which can efficiently photoelectrically convert by a photoelectric conversion device with little loss of light, and can easily and reliably attach a protective sheet.
A photoelectric conversion device for adhering a photoelectric conversion unit and a transparent protective sheet 1 in a state where a light incident surface of a photoelectric conversion unit that converts light energy into electricity and a bonding surface of a protective sheet 1 are opposed to each other. A method for attaching a protective sheet, wherein the light incident surface of the photoelectric conversion portion and the attachment surface of the protective sheet 1 are opposed to each other with the planarizing material 30 interposed therebetween, and the photoelectric conversion portion having a concavo-convex structure on the light incident surface; In the step of laminating the protective sheet 1 having a concavo-convex structure on the surface opposite to the application surface, and in the deformable state of the planarizing material 30 sandwiched between the light incident surface and the application surface, the photoelectric conversion unit and the protection sheet 1 And the step of sticking the protective sheet 1 to the light incident surface by the sticking force of the planarizing material 30.
[Selection] Figure 1

Description

  The present invention relates to a method for attaching a protective sheet for a photoelectric conversion device, a method for manufacturing a photoelectric conversion device, and a photoelectric conversion device.

  In a solar cell device as a photoelectric conversion device, generally, glass having excellent weather resistance, heat resistance, impact resistance, and transmittance is used as a translucent substrate on a light incident surface. And it has been proposed to prevent environmental damage caused by reflection when a resin sheet is pasted on the surface of the glass when installed outdoors (see Patent Document 1). In addition, if this resin sheet has sufficient impact resistance, the glass is difficult to break, and when the glass is broken, the glass pieces do not fall apart, and a merit in terms of safety and long-term operation of the solar cell panel is expected. However, since the weather resistance of the sheet itself and the weather resistance of the adhesive between the sheet and glass are worse than those of glass, it is difficult to maintain the desired performance for a long time. The present condition is that the goods which stuck the sheet do not exist. For this reason, there are many cases where performance such as anti-reflection is imparted by using glass that has been processed to provide irregularities on the glass surface. Further, if the resin sheet is attached to the concavo-convex glass with an adhesive by the method described in Patent Document 1, there is a risk that bubbles may be generated between the resin sheet and the concavo-convex glass. May be reflected and power generation efficiency may be reduced.

JP 2010-87351 A

  The present invention has been made based on the circumstances as described above, and it is an object of the present invention to be able to perform photoelectric conversion efficiently with a photoelectric conversion device with little light loss, and to easily and reliably attach a protective sheet. It is providing the manufacturing method of the sticking method of the protective sheet for photoelectric conversion apparatuses which can be performed, and a photoelectric conversion apparatus. Another object of the present invention is to provide a photoelectric conversion device that can efficiently perform photoelectric conversion with little loss of light and can be manufactured easily and reliably.

The present invention has been made in order to solve the above problems, and a method for attaching a protective sheet for a photoelectric conversion device according to the present invention includes:
A method for attaching a protective sheet for a photoelectric conversion device, in which a photoelectric conversion part and a protective sheet are attached in a state where a light incident surface of a photoelectric conversion part that converts light energy into electricity and an adhesive surface of a transparent protective sheet are opposed to each other. There,
The photoelectric conversion portion having a concavo-convex structure on the light incident surface and the concavo-convex structure on the surface opposite to the attachment surface so that the light incident surface of the photoelectric conversion portion and the attachment surface of the protective sheet are opposed to each other with a planarizing material interposed therebetween. A step of laminating a protective sheet having a photoelectric conversion portion and a protective sheet in a deformable state of the planarizing material sandwiched between the light incident surface and the pasting surface, A process of attaching a protective sheet to the light incident surface;
It is characterized by having.

  According to the method for applying a protective sheet for a photoelectric conversion device, the protective sheet can be applied to the light incident surface by an adhesive force of a flattening material, and in particular, since the light incident surface has an uneven structure, the adhesive force of the flattening material Is easy to act accurately. For this reason, the sticking state of the protective sheet on the light incident surface can be accurately obtained. In addition, since the photoelectric conversion device protective sheet sticking method sandwiches the photoelectric conversion portion and the protective sheet at the time of sticking, for example, even if bubbles exist in the fluidized flattening material, the air bubbles easily escape. By using the method for attaching a protective sheet for a photoelectric conversion device, it is possible to obtain a photoelectric conversion device in which bubbles are unlikely to exist between the light incident surface and the attachment surface and light loss due to the bubbles is small. Furthermore, since the surface opposite to the attachment surface of the protective sheet has a concavo-convex structure, by making this concavo-convex structure the target structure of the photoelectric conversion device, for example, the utilization rate of light is increased and the photoelectric conversion efficiency is improved. It is also possible to prevent environmental damage caused by the reflection of sunlight.

  In the method for attaching a protective sheet for a photoelectric conversion device, the protective sheet preferably includes a base material layer and a plurality of protrusions protruding from the surface side of the base material layer opposite to the attaching surface. Thus, the base material layer can be easily and reliably attached to the light incident surface, and the light incident on the protrusion is refracted toward the photoelectric conversion device, thereby improving the photoelectric conversion efficiency of the photoelectric conversion device. Can do.

  In the method for attaching a protective sheet for a photoelectric conversion device, the refractive index of the planarizing material is equal to or lower than the refractive index of the member constituting the light incident surface of the photoelectric conversion unit, and the refractive index of the protective sheet is equal to or lower than the refractive index of the planarizing material. Preferably there is. As a result, the refractive index does not increase from the protective sheet to the members constituting the light incident surface of the photoelectric conversion unit, so that the light incident from the surface side of the protective sheet is not easily reflected by each layer, and the photoelectric conversion efficiency of the photoelectric conversion device Is improved.

  The protective sheet sticking method for the photoelectric conversion device may employ a configuration in which the protective sheet contains a polymer resin as a main component. Thereby, a protective sheet having sufficient transparency and impact resistance can be easily and reliably manufactured.

  When this configuration is adopted, the planarizing material preferably contains the same polymer resin as that of the protective sheet as a main component. Thereby, it is excellent in the adhesive force of a protective sheet and the layer of planarization material.

  In the method for attaching a protective sheet for a photoelectric conversion device, the planarizing material is a thermoplastic resin, and after sandwiching the photoelectric conversion portion and the protective sheet, the planarizing material is solidified by lowering the temperature of the planarizing material. Can be adopted. Thereby, by sandwiching the photoelectric conversion part and the protective sheet, the protective sheet is defoamed from the planarized material in a fluid state, and then the temperature is lowered to solidify the planarized material so that the protective sheet is formed on the incident surface. Can be affixed.

  In the photoelectric conversion device protective sheet attaching method, the planarizing material is light or thermosetting resin, and the planarizing material is irradiated with light or heated after being sandwiched between the photoelectric conversion part and the protective sheet. It is possible to adopt a configuration that solidifies the material. Thus, the photoelectric conversion part and the protective sheet are sandwiched so that the planarizing material in a fluid state is defoamed, and then the incident surface is protected by solidifying the planarizing material by light irradiation or heating. A sheet can be attached.

  Moreover, the manufacturing method of the photoelectric conversion apparatus which concerns on this invention has the said protective sheet sticking method for photoelectric conversion apparatuses which consists of the said structure. Thereby, the manufacturing method of the photoelectric conversion device has a protective sheet on the surface, and as described above, the photoelectric conversion device can be easily and reliably affixed with the protective sheet attached to the light incident surface with little light loss. It can be manufactured reliably.

Furthermore, the photoelectric conversion device according to the present invention is
The light incident surface has a concavo-convex structure, a photoelectric conversion unit that converts light energy into electricity, and is laminated on the light incident surface side of the photoelectric conversion unit, and has a concavo-convex structure on the surface opposite to the surface that faces the light incident surface. A transparent protective sheet having
An intermediate layer is further provided between the photoelectric conversion unit and the protective sheet, and is in close contact with the light incident surface of the photoelectric conversion unit and the opposing surface of the protective sheet.

  In the photoelectric conversion device, the protective sheet can be attached to the incident surface of the photoelectric conversion unit by the adhesive force of the intermediate layer. Particularly, since the light incident surface has an uneven structure, the adhesive force of the intermediate layer is likely to act accurately. For this reason, the sticking state of the protective sheet to the light incident surface is ensured. In the photoelectric conversion device, since the intermediate layer is in close contact with the incident surface of the photoelectric conversion unit and the opposite surface of the protective sheet, bubbles are unlikely to exist between the light incident surface and the protective sheet. There is little loss. Furthermore, since the surface opposite to the attachment surface of the protective sheet has a concavo-convex structure, by making this concavo-convex structure the target structure of the photoelectric conversion device, for example, the utilization rate of light is increased and the photoelectric conversion efficiency is improved. It is also possible to prevent environmental damage caused by the reflection of sunlight.

  The “variable state of the flattening material” includes not only a fluid state such as a liquid but also a state that can be deformed by the action of pressure. For example, the photoelectric conversion unit and the protective sheet include It is a concept including a state in which the bubbles in the planarizing material can be deformed so as to be released to the outside when sandwiched.

  As described above, the present invention can efficiently perform photoelectric conversion with a photoelectric conversion device with little loss of light, and can easily and reliably attach the protective sheet to the light incident surface of the photoelectric conversion unit.

FIG. 1 is a schematic cross-sectional view of a method for attaching a protective sheet for a photoelectric conversion device according to an embodiment of the present invention, in which (A) is a state where a planarizing material is applied, and (B) is a state where protective sheets are laminated. Indicates. 2A and 2B are schematic enlarged cross-sectional views of the method for applying a protective sheet for a photoelectric conversion device in FIG. 1, in which FIG. 2A shows a state where a planarizing material is applied, and FIG. 2B shows a state where protective sheets are laminated. FIG. 3 is a schematic perspective view of the protective sheet in FIGS. 1 and 2. FIG. 4 is a schematic plan view of a protrusion of the protective sheet in FIG. FIG. 5 is a schematic front view of the protrusion of the protective sheet of FIG. FIG. 6 is a schematic front view in which the main part of the protrusion of the protective sheet in FIG. 3 is enlarged. FIG. 7 is a schematic plan view of the protective sheet of FIG. FIG. 8 is a schematic cross-sectional view of a photoelectric conversion device in which the protective sheet of FIG. 3 is used. FIG. 9 is a schematic cross-sectional view of a molding die used for molding the protective sheet of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a method for attaching a protective sheet for a photoelectric conversion device will be described.

<Method for applying protective sheet for photoelectric conversion device>
The photoelectric conversion device protective sheet sticking method of the present embodiment (hereinafter sometimes simply referred to as the sticking method) includes a light incident surface of the photoelectric conversion unit 20 that converts light energy into electricity and a sticking surface of the protective sheet 1. In this state, the photoelectric conversion unit 20 and the protective sheet 1 are stuck together. The said sticking method has a lamination process which laminates | stacks the photoelectric conversion part 20 and the protective sheet 1, and a sticking process which sticks the laminated | stacked photoelectric conversion part 20 and the protective sheet 1. FIG.

  In the stacking step, the photoelectric conversion unit 20 having a concavo-convex structure on the light incident surface so that the light incident surface of the photoelectric conversion unit 20 and the application surface of the protective sheet 1 face each other with the planarizing material 30 interposed therebetween, and the application surface This is a step of laminating the protective sheet 1 having a concavo-convex structure on the opposite surface. Various methods can be adopted for the layering process. For example, as shown in FIGS. 1A and 2A, by applying a liquid planarizing material 30 on the light incident surface, A step of forming a layer of the planarizing material 30 having fluidity, and a protective sheet 1 is laminated on the surface of the layer of the planarizing material 30 having fluidity as shown in FIGS. 1 (B) and 2 (B). And a process of performing.

  The sticking step sandwiches the photoelectric conversion unit 20 and the protective sheet 1 in a deformable state of the planarizing material 30 sandwiched between the light incident surface and the pasting surface, and attaches the light incident surface by the pasting force of the planarizing material 30. This is a step of attaching the protective sheet 1. Various methods can be used for this sticking step. For example, the step of sandwiching the laminated photoelectric conversion unit 20 and the protective sheet 1 and the planarizing material 30 having fluidity after this step are solidified. It is possible to have the process to make.

  The planarizing material 30 having fluidity in the laminating step preferably has a low viscosity, and specifically, preferably 1 mPa · s or more and 20000 mPa · s or less. Further, the temperature of the planarizing material 30 in each step of coating the planarizing material 30, laminating the protective sheet 1 on the surface of the coated layer, and sandwiching the protective sheet 1 is not particularly limited. It is preferably −40 ° C. or higher and 200 ° C. or lower, and more preferably 40 ° C. or higher and 150 ° C. or lower. Thereby, each operation | work can be performed stably. When a thermosetting resin is used as the planarizing material 30 as described later, the solidifying step is preferably performed at 40 ° C. or higher and 150 ° C. or lower.

  In the sandwiching step, for example, a method of passing a laminated body of the photoelectric conversion unit 20 and the protective sheet 1 between a pair of rollers can be employed. The linear pressure between the pair of rollers is not particularly limited, but is preferably 100 g / cm or more and 20 Kg / cm or less. If it is less than the lower limit, bubbles may remain between the light incident surface of the photoelectric conversion unit 20 and the protective sheet 1, and if the upper limit is exceeded, the photoelectric conversion unit 20 or the protective sheet 1 may be damaged. There is.

  As the photoelectric conversion unit 20, for example, a solar cell module can be adopted. As shown in FIG. 1, the solar cell module 20 is provided on a plurality of solar cells 21, a transparent sealing material 22 surrounding the solar cells 21, and the surface side of the sealing material 22. And a transparent translucent substrate 23 made of glass or the like. The solar cell module 20 also includes a back surface protection plate 24 disposed on the back surface side of the sealing material 22.

  The light incident surface of the photoelectric conversion unit 20 is composed of the surface of the light-transmitting substrate 23, and the surface of the light-transmitting substrate 23 has an uneven structure as described above. The uneven structure on the surface of the translucent substrate 23 is a fine uneven structure. The arithmetic average roughness (Ra) of the surface of the translucent substrate 23 is not particularly limited, but is preferably 10 nm or more and 30 μm or less, and more preferably 0.1 μm or more and 10 μm or less. Further, the ten-point average roughness (Rz) of the surface of the translucent substrate 23 is not particularly limited, but is preferably 10 nm or more and 300 μm or less, and more preferably 0.1 μm or more and 100 μm or less. . The arithmetic average roughness (Ra) and the ten-point average roughness (Rz) are numerical values calculated in accordance with JIS-B-0601 based on a value measured in a 1 mm square.

  The protective sheet 1 can be composed of a transparent resin sheet. As described above, the surface of the protective sheet 1 (the surface opposite to the sticking surface) has a concavo-convex structure. Specifically, the protective sheet 1 includes a base material layer as shown in FIGS. 2 and a plurality of protrusions 3 protruding from the surface of the base material layer 2. The protective sheet 1 includes a sheet that blocks ultraviolet rays as described in JP 2010-23148, a sheet that blocks infrared rays as described in JP 2011-77179, and JP 2011-9536. It is also possible to employ a condensing sheet such as

  As shown in FIG. 3, the protective sheet 1 in FIGS. 1 and 2 has a plurality of protrusions 3 arranged in the form of dots on the surface of a base material layer 2 having a surface view. In addition, the some protrusion part 3 is mutually arrange | positioned with a clearance gap, and the base material layer 2 has a substantially smooth plane part (site | part in which the protrusion part 3 is not formed) on the surface.

  The bottom surface of the protrusion 3 preferably has a one-time symmetry or a two-time symmetry shape. The protrusion 3 shown in FIG. 3 has a substantially inverted triangular prism shape, and the bottom surface of the protrusion 3 has a two-fold symmetrical shape. Note that the two-fold symmetry means a figure that overlaps the original figure at 180 degrees when the figure is rotated. As shown in FIG. 4, the bottom surface of the protruding portion 3 includes two linear portions (hereinafter sometimes referred to as long side portions 5) orthogonal to the short axis and facing each other, and two orthogonal portions facing the long axis and facing each other. It is formed in a substantially polygonal shape having a straight line portion (hereinafter also referred to as a short side portion 6), specifically, a substantially rectangular shape. In addition, the protrusion part can employ | adopt what a bottom face is substantially elliptical shape. In addition, it is also possible to employ a protrusion having a curved bottom face in a longitudinal direction and a substantially arcuate side (side along the longitudinal direction) of the bottom face.

  The bottom surface of the protrusion 3 preferably has a circumference of 50 μm or more and 10 cm or less. Here, the ratio of the length L (long axis length) of the long side portion 5 to the length W (short axis length) of the short side portion 6 is set to 2 or more and 1000 or less. The bottom surface of the protrusion 3 is formed of a smooth line whose outer periphery does not have discontinuities. Specifically, a curved portion 7 that continuously connects the long side portion 5 and the short side portion 6 is provided between the long side portion 5 and the short side portion 6 (rectangular corner portion). .

  As for this projection part 3, the cross-sectional shape in the plane containing both the normal line direction and short-axis direction of the protective sheet 1 is formed in the substantially triangular shape as shown in FIG. Specifically, this cross-sectional shape is a substantially isosceles triangle. The protrusion 3 has a height H that is not less than 0.8 times and not more than 3 times the length W in the minor axis direction.

  The protrusion 3 has four side surfaces 9 and 10 rising from the bottom surface to the surface side. Of these four side surfaces 9 and 10, the side surface 10 rising from the short side portion 6 of the bottom surface rises substantially perpendicular to the planar direction of the base material layer 2 and is formed in a substantially triangular shape. Further, the remaining two side surfaces 10 (side surfaces rising from the long side portion 5 of the bottom surface) are inclined so as to approach the other side surface as the surface side is formed, and are formed in a substantially rectangular shape. The inclination angle of the two side surfaces 9 with respect to the surface direction of the base material layer 2 is substantially constant from the back surface to the surface, but is formed in a smooth curved surface having no discontinuities near the top 11 and the bottom. ing. This curved surface will be described later. Further, the cross-sectional shape of the protrusion 3 is not limited to the above-described triangular shape, and for example, protrusions having various cross-sectional shapes such as a substantially semicircular shape and a substantially rectangular shape can be employed.

  As shown in FIGS. 3 and 4, the protrusion 3 has a ridge line 12 that is substantially parallel to the major axis at the top 11. The ridgeline 12 is provided with substantially the same length as the major axis. Further, as shown in FIG. 5, the top portion 11 of the protrusion 3 is formed of a smooth curved surface having no discontinuities, and specifically, the oblique sides of substantially isosceles triangles are continuously connected to each other. It is formed in a curved shape.

  As shown in FIGS. 5 and 6, the protrusion 3 has a curved skirt 13 that is continuous from the side surface 9 having a constant inclination angle to the surface of the base material layer 2. The skirt 13 is continuous from the side surface 9 of the protrusion 3 and is formed so that the inclination angle gradually decreases from the continuous portion with the side surface 9 to the base material layer 2 side and continues to the surface of the base material layer 2. Has been. The skirt can also be formed between the side surface 9 rising vertically and the surface of the base material layer 2 (not shown). However, in the protective sheet 1, the skirt 13 is not an essential constituent element. In the present specification, the bottom surface of the protrusion 3 of the protective sheet 1 means a concept that does not include the skirt 13, and is one point in FIG. 6. As indicated by a chain line, a region surrounded by the virtual surface of the side surface 9 of the protrusion 3 and the virtual surface of the base material layer 2 means the bottom surface of the protrusion 3.

  The side surface 9 (side surface intersecting the short axis) rising from the long side portion 5 of the bottom surface of the protrusion 3 is formed so that the rising angle is 65 degrees or more and 90 degrees or less. Note that in the protective sheet 1, the rising angle means an angle calculated without including the skirt portion 13, and as indicated by a one-dot chain line in FIG. 6, the virtual surface of the side surface 9 of the protrusion 3 and the base material It means the angle α formed with the virtual surface of the layer 2. In addition, the inclination angle of the side surface is the same as the rising angle α in the present embodiment.

  The plurality of protrusions 3 are arranged in a dotted manner as described above, and the short axis of the bottom surface of one protrusion 3 and the short axis of the bottom surface of another adjacent protrusion 3 are substantially parallel. It is arranged to become. Specifically, as shown in FIG. 7, the short axes of the plurality of protrusions 3 are arranged so as to be parallel to each other. Moreover, the some projection part 3 consists of substantially the same shape, and is arrange | positioned in the alignment state front and rear, right and left (refer FIG.3 and FIG.7). That is, the plurality of protrusions 3 are arranged such that the long side portions 5 are arranged in a straight line and the short side portions 6 are also arranged in a straight line. In the present embodiment, the plurality of protrusions 3 are arranged such that each side 2a of the rectangular base layer 2 is substantially parallel to the major axis and the minor axis. In addition, it is also possible to change the design so that the plurality of protrusions 3 are arranged so as to be inclined at a certain angle with respect to each side 2a of the base material layer 2 (for example, inclined at 45 degrees). The arrangement pattern of the plurality of projections 3 is not limited to the above, and various arrangement patterns such as random, concentric circles, and radial patterns can be adopted, and a plurality of arrangement patterns can be provided. . Further, it is possible to adopt a structure in which a plurality of protrusions having different shapes are arranged in an appropriate arrangement pattern.

  The plurality of protrusions 3 are provided such that the total area (plan view) of the bottom surface is 1/3 or more of the total area (plan view) of the surface of the base material layer 2. That is, the total area of the bottom surfaces of the plurality of protrusions 3 is provided more than twice the surface of the base material layer 2 exposed on the surface side without the protrusions 3 being formed.

  The protrusion 3 is formed integrally with the base material layer 2. Specifically, the base material layer 2 and the protrusion 3 are integrally molded by a molding die 40 having a hole corresponding to the protrusion 3.

  The material for forming the base material layer 2 and the protrusions 3 of the protective sheet 1 is not particularly limited, but the base material layer 2 and the protrusions 3 preferably contain a polymer resin as a main component. An example of the polymer resin is a silicone resin.

  As the silicone resin, those generally used can be used. Of these silicone resins, straight silicone resins and modified silicone resins are preferred. One type of these silicone resins may be selected, or two or more types may be used in combination. Here, “straight silicone resin” is a polymer (resin) in which a methyl group, a phenyl group, or a hydrogen atom is bonded to a polysiloxane skeleton as a substituent, and “modified silicone resin” is secondary to a straight silicone resin. Is a polymer that is functionalized by binding functional groups.

  Examples of the straight silicone resin include methyl silicone resin and methylphenyl silicone resin.

  Examples of the modified silicone resin include epoxy-modified silicone resin, epoxy-polyether-modified silicone resin, carbinol-modified silicone resin, methacryl-modified silicone resin, phenol-modified silicone resin, methylstyryl-modified silicone resin, acrylic-modified silicone resin, methyl Examples thereof include hydrogen silicone resins.

  Moreover, you may add antioxidant, a mold release agent, a coupling agent, an inorganic filler, etc. with respect to this silicone resin in the range which does not impair the characteristic.

  The silicone resin can be obtained using a known silane compound. Examples of the silane compound include methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltrit -Butoxysilane; ethyltrichlorosilane, ethyltribromosilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltrit-butoxysilane; n-propyltrichlorosilane, n-propyltribromosilane, n- Propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltriisopropoxysilane, n-propyltri-t-butoxysilane; n-hexyltrichlorosilane, n-hexyltribromo Lan, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-hexyltriisopropoxysilane, n-hexyltrit-butoxysilane; n-decyltrichlorosilane, n-decyltribromosilane, n-decyltrimethoxy Silane, n-decyltriethoxysilane, n-decyltriisopropoxysilane, n-decyltrit-butoxysilane; n-octadecyltrichlorosilane, n-octadecyltribromosilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxy Silane, n-octadecyltriisopropoxysilane, n-octadecyltri-t-butoxysilane; phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyl Ditrichloropropoxysilane, phenyltri-t-butoxysilane; dimethoxydiethoxysilane; dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldiethoxysilane; diphenyldichlorosilane, diphenyldibromosilane, diphenyldimethoxysilane, Diphenyldiethoxysilane; phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane; trichlorohydrosilane, tribromohydrosilane, trimethoxyhydrosilane, triethoxyhydrosilane, triisopropoxyhydrosilane, trit -Butoxyhydrosilane; vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltri Ethoxysilane, vinyltriisopropoxysilane, vinyltri-t-butoxysilane; γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycid Xylpropyltriethoxysilane, gamma-glycidoxypropyltriisopropoxysilane, gamma-glycidoxypropyltri-t-butoxysilane; gamma-methacryloxypropylmethyldimethoxysilane, gamma-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropyltri-t-butoxysilane; Propylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltrit-butoxysilane; γ -Mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-butoxysilane Β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane; and partial hydrolysates thereof; and The mixture can be used.

  The refractive index of the base material layer 2 and the protrusion 3 is preferably larger than the refractive index of air and smaller than the refractive index of the translucent substrate 23 of the photoelectric conversion unit 20. Specifically, it is preferable that the refractive index of the base material layer 2 and the protrusion part 3 is 1.1 or more and 1.5 or less.

  The total light transmittance of the protective sheet 1 is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more. Thereby, there is little loss of a light ray and it can contribute by the improvement of the power generation efficiency of a photoelectric conversion apparatus. The total light transmittance is a value measured according to JIS K7361-1, and can be measured using a haze meter (NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.).

  The material of the planarizing material 30 is not particularly limited, and various materials can be adopted. As the planarizing material 30, for example, a material containing a polymer resin as a main component can be employed, and a thermoplastic resin, a photo-curing resin, a thermosetting resin, or the like can be employed. .

  The polymer resin as the main component of the planarizing material 30 is not particularly limited, but the polymer resin as the main component of the protective sheet 1 can be employed, and examples thereof include a silicone resin. As this silicone resin, what is generally used can be used, and since it becomes the description similar to the protection sheet 1, detailed description is abbreviate | omitted.

  When a thermoplastic resin is used as the planarizing material 30, a thermoplastic resin sheet can be used as the planarizing material 30. Examples of the thermoplastic resin sheet include EVA (NUC-3758 manufactured by Nihon Unicar, Inc.), fluororesin (PVdF and Dyneon THV, Dyneon PFA manufactured by Sumitomo 3M), ionomer resin (High Milan manufactured by Mitsui DuPont Polychemical Co., Ltd.), TPE (WO2011). Conjugated diene block copolymer and hydrogenated product thereof, and methylpentene polymer (TPX) manufactured by Mitsui Chemicals. The thermoplastic resin sheet is preferably TPE, EVA, or ionomer resin from the viewpoint of weather resistance and fluidity.

  The planarizing material 30 preferably has a solidified refractive index that is greater than or equal to the refractive index of the protective sheet 1 and less than or equal to the refractive index of the translucent substrate 23 of the photoelectric conversion unit 20. Specifically, the refractive index of the layer made of the planarizing material 30 is preferably 1.1 or more and 1.5 or less. As a result, the refractive index does not increase from the protective sheet 1 to the members constituting the light incident surface of the photoelectric conversion unit 20, so that the light incident from the surface side of the protective sheet 1 is not easily reflected by each layer, and the photoelectric conversion device The power generation efficiency is improved.

  When the planarizing material 30 is solidified, the planarizing material 30 is preferably in a physical adhesive state without being chemically bonded to the protective sheet 1 and the translucent substrate 23. The chemical adhesion means a state in which there is a chemical interaction with the layer in contact with the layer of the planarizing material 30, and the physical adhesion means a chemical interaction with the layer in contact with the layer of the planarizing material 30. It means a state of physical adsorption rather than action.

  Here, the tensile strength between the protective sheet 1 and the translucent substrate 23 attached by the attaching force of the planarizing material 30 is preferably 1 N / 15 mm or more and 30 N / 15 mm or less, and 3 N / 15 mm or more and 15 N. / 15 mm or less is more preferable, and 5 N / 15 mm or more and 10 N / 15 mm or less is particularly preferable. This tensile strength is a value measured according to JIS-K-6854.

<Method for Manufacturing Photoelectric Conversion Device>
Next, the manufacturing method of the photoelectric conversion apparatus using the said sticking method is demonstrated. The manufacturing method of this photoelectric conversion apparatus sticks the process of manufacturing the said solar cell module 20, the process of forming the said protection sheet 1, and the solar cell module 20 and the protection sheet 1 obtained by these processes. The sticking method is provided. In this method of manufacturing a photoelectric conversion device, the formed protective sheet 1 is first pasted on the translucent substrate 23 by the pasting method, and the solar cell using the translucent substrate 23 with the protective sheet 1 is used. It is also possible to employ a method of manufacturing the device.

  The process for producing the solar cell module 20 is not particularly limited. For example, the translucent substrate 23, a sealing material sheet made of a thermoplastic resin, a solar battery cell, and other sealing made of a thermoplastic resin. The solar cell module 20 can be manufactured by laminating the material sheet and the back surface protection plate in this order and integrally laminating and bonding them by a vacuum heating laminating method.

  Although the manufacturing process of the said protection sheet 1 is not specifically limited, For example, it can manufacture using the shaping | molding die 40. FIG.

  As the mold 40 used here, for example, as shown in FIG. 7, a mold having a plurality of recesses 40a capable of forming the protrusions 3 of the protective sheet 1 can be used. The opening surface of the recess 40a is provided corresponding to the shape of the bottom surface of the protrusion 3, the shape of the recess 40a is provided corresponding to the shape of the protrusion 3, and the plurality of recesses 40a is an arrangement of the plurality of protrusions 3. It is arranged corresponding to. Various materials can be used for the mold 40, and for example, a metal such as nickel or the same kind of glass as the forming material of the protective sheet 1 described above can be used. Further, the overall shape of the mold 40 may be a flat plate shape or a cylindrical shape.

  The manufacturing method of the mold 40 is not particularly limited, but for example, a method using photolithography can be adopted. In this manufacturing method, an exposure process in which the resist surface is covered with a photomask having a predetermined pattern (arrangement pattern of protrusions 3), a process of developing the exposed resist, and a surface of the developed resist It is possible to employ a method having a step of forming the mold 40 by laminating the mold forming material. In this manufacturing method, exposure and development are performed so that the developed resist has the same shape as the protrusions 3 of the protective sheet 1. The step of forming the mold 40 can employ, for example, a method of electroforming a nickel layer on the surface of the resist and then removing the resist. Moreover, the process of forming the shaping | molding die 40 creates the laminated body which apply | coated the photosensitive glass paste to the said resist surface, winds this laminated body around a glass tube, and is photosensitive by irradiating a light ray from the inner side of a glass tube. It is possible to employ a method of curing the glass paste and then removing the resist.

  Various apparatuses can be adopted as a manufacturing apparatus for the protective sheet 1 having the molding die 40. For example, a material for forming the protective sheet 1 is supplied to the molding die 40 having the above-described configuration and the recess 40a of the molding die 40. It is possible to use an apparatus having a supply unit that performs the above operation. Moreover, when using a photocurable forming material as a forming material of the protection sheet 1, this apparatus is further provided with the light imprint part which irradiates light to the photocurable forming material of the recessed part 40a supplied by the supply part. It is also possible.

  An example of the manufacturing method of the protective sheet 1 using this manufacturing apparatus will be described. This manufacturing method includes a step of supplying the protective sheet 1 forming material to the mold 40, a step of curing the supplied protective sheet 1 forming material, And a step of separating the protective sheet 1 obtained by curing from the mold 40. When a photocurable material is used as the protective sheet forming material, it is possible to perform light irradiation in the curing step.

<Photoelectric conversion device>
The photoelectric conversion device in which the protective sheet 1 is attached to the surface (light incident surface) of the solar cell module 20 (photoelectric conversion unit 20) is manufactured by the method for manufacturing the photoelectric conversion device. For this reason, the photoelectric conversion device has a concavo-convex structure on the light incident surface, is stacked on the light incident surface side of the photoelectric conversion unit 20 that converts light energy into electricity, and faces the light incident surface. A transparent protective sheet 1 having a concavo-convex structure on the surface opposite to the surface, and laminated between the photoelectric conversion unit 20 and the protective sheet 1, and a light incident surface of the photoelectric conversion unit 20 and the protective sheet 1 An intermediate layer in close contact with the opposing surface is provided. The intermediate layer is a layer made of the planarizing material 30. Here, the fact that the intermediate layer is in close contact with each surface means a state in which the intermediate layer is in close contact with the surface without performing chemical bonding, and means that the intermediate layer is in a physical adhesion state.

In the photoelectric conversion device, since the protective sheet 1 is attached by the attaching method, almost no bubbles exist between the light incident surface of the photoelectric conversion unit 20 and the attached surface of the protective sheet 1. Here, the ratio of bubbles to the surface area of the photoelectric conversion device is preferably 100 / m ² or less, more preferably 20 / m ² or less, and 5 / m ² or less. Particularly preferred. In addition, regarding the measurement of the abundance ratio of the bubbles, the number of bubbles having a spherical equivalent diameter of 100 μm or more in 10 cm square is measured and calculated.

<Advantages>
The said embodiment has the following advantages from the said structure. In the sticking method, the protective sheet 1 can be stuck to the light incident surface by the sticking force of the planarizing material 30. Here, since the sticking force of the planarizing material 30 is based on physical adhesion rather than chemical adhesion, it can be relatively easily peeled off when the protective sheet 1 needs to be peeled off. For this reason, even if the photoelectric conversion device with the protective sheet 1 attached is used outdoors for a long period (for example, three years) and the translucency of the protective sheet 1 is deteriorated, the deteriorated protective sheet 1 is peeled off and new By sticking the protective sheet 1, it is possible to suppress a decrease in the photoelectric conversion rate of the photoelectric conversion device.

  In addition, since the light incident surface has a fine concavo-convex structure, the sticking force by physical bonding of the planarizing material 30 is likely to act accurately. For this reason, the sticking state of the protective sheet 1 to the light incident surface is ensured. Moreover, since the protective sheet 1 functions as the protective sheet 1 of the solar cell module 20, it is possible to accurately prevent the translucent substrate 23 from being damaged by an unintentional external force. Further, since the protective sheet 1 is laminated on the translucent substrate 23 with the adhesive force of the layer of the planarizing material 30, even if the translucent substrate 23 is damaged, the fragments of the translucent substrate 23 are scattered around. hard.

  Furthermore, in the sticking method, the photoelectric conversion unit 20 and the protective sheet 1 are sandwiched at the time of sticking, so that bubbles are hardly generated between the light incident surface and the protective sheet 1. For this reason, while being able to prevent the sticking force fall by a bubble, the loss of the light by a bubble is little. For this reason, efficient photoelectric conversion can be performed.

  Further, the protective sheet 1 has a plurality of protrusions 3 protruding from the surface side of the base material layer 2, and guides light incident from the surface side of the protrusions 3 to the base material layer 2 side to photoelectrically The light can be emitted toward the solar battery cell 21 of the conversion device. Since the protrusion 3 is tapered and has a higher refractive index than air, it can be refracted so that the incident light is inclined with respect to the normal direction of the protective sheet 1 so as to be close to the normal direction. It can be emitted as a light beam close to the vertical direction with respect to the solar battery cell 21. For this reason, the power generation efficiency of the photoelectric conversion device is improved.

  In the protective sheet 1, the shape of the bottom surface of the protrusion 3 is symmetrical once or twice, and the plurality of protrusions 3 are arranged in a dotted pattern. Even if the incident direction changes, there is little change in the intensity of light emitted toward the photoelectric conversion device. In particular, since the bottom surface of the protrusion 3 has a substantially rectangular shape, a light beam can easily enter from the side surface 9 on the long side portion side, and the incident light beam can be emitted toward the photoelectric conversion device. Furthermore, since the projection part 3 has the ridgeline 12 substantially parallel to the long axis of the bottom face, the area of the side face 9 on the long side part side is large, and light rays are more likely to enter.

  Since the ratio of the major axis to the minor axis of the bottom surface of the projecting portion 3 is 2 or more and 1000 or less, it is easy for light to enter from the side surface 9 and to easily arrange the plurality of projecting portions 3 accurately. That is, if the ratio of the major axis to the minor axis is less than the lower limit value, the length of the major axis is short, the area of the side surface 9 is small, and the light beam may not be incident on the protrusion 3. On the other hand, if the ratio exceeds the upper limit value, the protrusions 3 are too thin in plan view, and there is a risk that efficient arrangement of the plurality of protrusions 3 may be difficult, and further, from the side surface 9 that intersects the short axis. May not be able to be expected to be incident. The lower limit of the ratio of the major axis to the minor axis is preferably 2, more preferably 4, and even more preferably 6. In addition, the upper limit of the ratio of the major axis to the minor axis is preferably 1000, more preferably 100, and even more preferably 10.

  Since the major axis of the bottom surface of the plurality of protrusions 3 is arranged substantially in parallel, the side surface 9 intersecting with the minor axis has a larger area than the side surface 10 intersecting with the major axis, and is compared with the light beam from the major axis direction. Therefore, the protective sheet 1 is disposed so that the short axis direction of the protrusion 3 is positioned along the incident direction of the light beam that can contribute most to power generation. The power generation efficiency of the solar cell module 20 can be increased.

  The plurality of protrusions 3 have long sides 5 arranged in a straight line, and the protective sheet 1 is formed with grooves along the long sides 5 by the plurality of protrusions 3. Tends to flow along the direction of the long side portion 5. Further, since the short side portions 6 are also arranged in a straight line, the water easily flows along the direction of the short side portions 6 as well.

  Since the total area of the bottom surfaces of the plurality of protrusions 3 is 1/3 or more of the total area of the surface of the base material layer 2, the protrusions 3 are sufficiently disposed on the surface side of the base material layer 2, and photoelectric conversion is performed. The power generation efficiency of the device can be increased. That is, if the total area of the bottom surface of the protrusion 3 is less than the lower limit, the existence ratio of the protrusion 3 is small, and there is a possibility that sufficient power generation efficiency cannot be improved. The ratio of the total area of the bottom surface of the protrusion 3 to the total area of the surface of the base material layer 2 is preferably 1/3 or more, more preferably 1/2 or more, and 2/3 or more. More preferably it is. On the other hand, the ratio of the total area of the bottom surface of the protrusion 3 to the total area of the surface of the base material layer 2 is preferably 19/20 or less, more preferably 9/10 or less, and 17/20 or less. More preferably it is. If the ratio of the total area of the bottom surfaces of the protrusions 3 exceeds the upper limit, it may be difficult to form the protrusions 3.

  Since the peripheral length of the bottom surface of the protrusion 3 is 50 μm or more and 10 cm or less, and the ratio of the height of the protrusion 3 to the length of the bottom surface of the protrusion 3 in the short axis direction is 0.8 or more and 3 or less, the protrusion 3 Has a sufficient size and height, the light beam is preferably incident on the protrusion 3. That is, if the peripheral length and height of the bottom surface of the protrusion 3 are less than the lower limit value, it is difficult for light rays to enter the protrusion 3. On the other hand, if the height of the protrusion 3 exceeds the upper limit, the protrusion 3 becomes too high, and the strength of the protrusion 3 may be lacking. Moreover, when the circumference of a bottom face exceeds the said upper limit, there exists a possibility that suitable arrangement | positioning of the several projection part 3 may become difficult. Note that the lower limit value of the circumferential length of the bottom surface of the protrusion 3 is preferably 50 μm, more preferably 0.5 mm, and even more preferably 1 mm. Moreover, 10 cm is preferable, as for the upper limit of the peripheral length of the bottom face of the projection part 3, 5 cm is more preferable, and 2 cm is more preferable. Further, the lower limit value of the ratio of the height of the protrusion 3 is preferably 0.8, more preferably 1, and still more preferably 1.2. The upper limit of the ratio of the height of the protrusion 3 is preferably 3, more preferably 2.5, and even more preferably 2.

  Since the rising angle α of the side surface 9 of the protrusion 3 is 65 degrees or more and 90 degrees or less, the light beam can accurately enter the protrusion 3, and the intensity of the protrusion 3 is sufficient. The protrusion 3 can be easily formed. That is, when the rising angle α is less than the lower limit value, the protrusion 3 cannot obtain a sufficient height, and when it is intended to obtain a sufficient height, the inclination angle of the side surface 9 is set higher than the rising angle. However, since the shape needs to be increased and the shape becomes distorted, the strength may be lost and molding may be difficult. On the other hand, if the rising angle α exceeds the upper limit, the strength of the protrusion 3 is insufficient, the protrusion 3 may be inadvertently detached due to inadvertent contact or the like, and molding may be difficult. . The lower limit value of the rising angle α is preferably 60 degrees, more preferably 65 degrees, and further preferably 70 degrees. On the other hand, the upper limit value of the rising angle α is preferably 90 degrees, more preferably 85 degrees, and further preferably 80 degrees.

  The inclination angle of the side surface 9 of the protrusion 3 is the same as the rising angle α, that is, the inclination angle of an arbitrary point on the side surface 9 of the protrusion 3 is equal to or less than the rising angle α, and thus the strength of the protrusion 3 is strong. At the same time, molding can be performed easily and reliably.

  Since the protrusion 3 is formed in a shape that does not have discontinuous points, dirt or the like is less likely to adhere thereto, and molding can be performed easily and reliably. That is, the bottom surface of the protrusion 3 has a curved portion 7 and the outer periphery of the bottom surface is formed of a smooth line having no discontinuity, and the skirt 13 is provided near the rising portion of the protrusion 3. The side surface 9 of the protrusion 3 and the surface of the base material layer 2 are continuously provided by the skirt 13, and further, the top 11 is provided with a curve, so that dirt and the like are not easily attached and molding is easy. And it can be done reliably. In particular, since the top portion 11 is provided in a curved shape, there is little possibility of damaging other members even if they are contacted by other members.

  When the base sheet 2 and the protrusion 3 are integrally molded, the protective sheet 1 is less likely to be inadvertently detached from the base layer 2, and the protective sheet 1 is easily and reliably manufactured by molding. can do.

  Since the protective sheet 1 contains an inorganic material as a main component, and specifically contains a silicone resin or glass as a main component, the transparent protective sheet 1 can be easily and reliably formed.

<Other embodiments>
The present invention can be carried out in various modifications and improvements in addition to the above embodiment.

  In the above-described embodiment, the description has been given of the application of the fluidized planarizing material 30 to the light incident surface of the photoelectric conversion unit 20. However, the thermoplastic resin film is used as the planarizing material, and the thermoplastic resin film is sandwiched therebetween. It is also possible to employ a method in which the photoelectric conversion portion and the protective sheet are laminated in a state, and then the laminated body is heated to pressurize (clamp) the thermoplastic resin film in a molten state.

  Further, even when the liquid planarizing material is sandwiched between the light incident surface and the pasting surface, it is not limited to the above-mentioned coating, and the light incident surface and the pasting surface are bonded together. It is also possible to employ a method of dropping a liquid planarizing material just before the light incident surface and the pasting surface.

  Further, even when a method of applying a liquid leveling material is employed, it is possible to apply a leveling material having fluidity to the application surface of the protective sheet. It is also possible to change the design as appropriate to apply the planarizing material to both the light incident surface and the pasting surface.

  Further, when the liquid planarizing material has a certain fluidity when solidified, a method of solidifying the liquid planarizing material before laminating the protective sheet can be employed. That is, for example, a liquid flattening material is applied to the light incident surface, the liquid flattening material is solidified, and then a protective sheet is laminated on the surface side of the incident surface (the surface of the layer made of the flattening material). In addition, a method of sandwiching the protective sheet and the photoelectric conversion unit with a pressure roller or the like can be employed.

  Note that steps such as sandwiching the photoelectric conversion portion and the protective sheet and solidifying the above-described planarizing material can be performed under reduced pressure. Thereby, air bubbles are less likely to exist between the photoelectric conversion unit and the protective sheet.

  In addition, the material used for the planarizing material is not limited to that of the above embodiment, but the impact can be reduced, light can be guided to the photoelectric conversion element efficiently, and it is sufficient even outdoors. It has excellent weather resistance, has a function such that it does not deteriorate in function for 1 year or more, more preferably 3 years or more, and can maintain an adhesive state, or can be easily peeled off from the solar cell surface, and no peeling residue remains. It is preferable. In addition, it is preferable that the protective sheet is configured to have a similar function.

  Further, the planarizing material and the protective sheet may contain an ultraviolet absorber, an antioxidant, and the like as a weather resistance improver. Examples of the antioxidant include hindered phenol compounds such as BHT (2,6-di-t-butyl-p-cresol) and trade name “Irganox 1010” (manufactured by Ciba Specialty Chemicals); Examples thereof include benzotriazole compounds, benzophenone compounds, triazine compounds, benzoate compounds, hindered amine compounds such as trade names “Tinuvin 326” and “Tinuvin 328” (manufactured by Ciba Specialty Chemicals Co., Ltd.).

  Further, the protective sheet to be attached can be a single sheet having a size equivalent to that of the photoelectric conversion unit, and a plurality of protective sheets having a size smaller than that of the photoelectric conversion unit are arranged on the entire light incident surface. It is also possible to affix.

  In addition, although the method using the shaping | molding die 40 was demonstrated as a formation method of the said projection part 3, it is also possible to form a projection part directly with a photoresist etc. FIG. Further, even when a mold is used, it is not limited to a resin that is cured by irradiating light to a photocurable resin. For example, a flowable thermoplastic resin is supplied to the mold and cooled. It is possible to change the design as appropriate.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

<Example 1>
Liquid flattening material (SIM360, CAT360 mixture made by Shin-Etsu Chemical Co., Ltd.) on the surface (uneven glass surface) of a light-transmitting substrate of a single crystal silicon solar cell panel (NQ-190AA manufactured by Sharp Corporation; 116.5 cm × 99 cm); 200 g of a viscosity = 7000 mPa · s, a refractive index of 1.4) was applied and cast uniformly in the surface with a squeegee. Then, it was left as it was for one day, and was flattened and cured to form a silicone rubber layer (flattened layer) having a thickness of about 80 μm on the uneven glass surface. At this time, no bubbles remained at the interface between the silicone rubber layer and the concavo-convex glass surface, and the adhesive strength with the concavo-convex glass surface was good. Next, a 30 cm square prism sheet (LP40-0.3 manufactured by Nippon Special Optical Resin Co., Ltd.) as a protective sheet is applied to the surface of the light-transmitting substrate of the solar cell panel (flattened) so that the axial direction of the prism is random. The surface of the layer made of the material was arranged like a patchwork, and then the solar cell panel and the prism sheet were sandwiched by a pressure roller, so that the prism sheet was adhered while defoaming the bubbles of the silicone rubber layer. As for the power generation performance of the solar cell device formed in this way, the power generation efficiency was improved as compared with the solar cell device not attached with the prism sheet.

<Example 2>
In Example 2, a protective sheet produced as follows was used. Phosphor powder (Lumogen F Orange 240, manufactured by BASF) having a maximum absorption wavelength of 525 nm and a maximum emission wavelength of 571 nm in polymethacrylic acid resin (melt flow rate 1.5 g / 10 min) (product name: VH6, manufactured by Mitsubishi Rayon) ) Was produced by extrusion molding using a screw L / D = 20 and a cylinder temperature of 220 ° C. to obtain a protective sheet (A) having a thickness of 0.1 mm. . This refractive index was 1.49.

  This protective sheet was attached to the same solar cell panel as in Example 1. Specifically, 200 g of the same liquid flattening material as in Example 1 was dropped on the end of the short side of the solar cell panel, and the end of the protective sheet (A) wound up in a roll shape was overlaid thereon, A roller having a diameter of 10 cm and a width of 90 cm is disposed thereon, the protective sheet (A) is pressed against the panel with this roller, and the protective sheet (A) is sent out from the roll body of the protective sheet as the roller advances. Bonding was performed while expelling air bubbles between the panel and the planarizing material, and between the planarizing material and the protective sheet (A). Thus, after making the state which laminated | stacked the solar cell panel, the layer which consists of planarization material, and the protection sheet (A) without a bubble, this planarization body is heated to 100 degreeC for 30 minutes by oven, and planarization material is obtained. Solidified. In the solar cell device thus obtained, no bubbles remained at the bonding interface, the bonding strength at each interface was good, and the power generation performance was improved.

<Example 3>
In Example 3, the protective sheet manufactured as described below was used. First, a mold for manufacturing the protective sheet will be described.

(About molds)
When manufacturing this mold, a mold-forming sheet was prepared. In creating the mold forming sheet, first, a negative dry film resist (HM-4075, manufactured by Hitachi Chemical Co., Ltd.) was exposed without peeling off the cover film and the base film. For this exposure, a photomask having a large number of through holes having a short side of 30 μm and a long side of 1 mm was used. The exposure was performed with 150 mJ / cm 2 of UV light using a high-pressure mercury lamp. The cover film is peeled off from the exposed negative-type dry film resist, and shower development is performed for 1 min using a 0.5 wt% aqueous sodium bicarbonate solution at a liquid temperature of 25 ° C. and a development pressure of 0.1 MPa. The exposed part was removed. Thus, a mold forming sheet having a plurality of inverted triangular prism-shaped protrusions having a bottom width of 50 μm and a height of 75 μm was prepared.

  An electroless nickel plating layer having a thickness of 0.2 μm was formed on the surface of the mold forming sheet on which the protrusions were formed, and then nickel electroforming was performed using the nickel plating layer as an electrode until the thickness became 1 mm. The base film is peeled off from the obtained nickel mold, and residues such as resist are removed by baking at 500 ° C. for 1 hour under an air stream, and formed with nickel having a tapered groove with an opening diameter of 50 μm and a depth of 75 μm. A mold (hereinafter sometimes referred to as a nickel mold) was created.

(Protective sheet (B) of Example 3)
A protective sheet (B) of Example 3 was prepared using the nickel mold. First, based on silyl hydride having a nickel type having a number average molecular weight of about 1850, poly (dimethylsiloxane) having vinyl groups at both ends thereof, 10 g, three Si—H groups, and a number average molecular weight of about 1200. Filling the groove pattern of the mold by applying a silicone composition in which 1.09 g of dimethylsiloxane, 0.27 g of platinum-divinyltetramethyldisiloxane complex (Pt in an amount of 0.054 mass%), and 28 mg of dimethyl maleate were applied. Further, a film was formed so that the total thickness of the silicone layer was 200 μm. Thereafter, this silicone layer was cured by heating for 5 minutes on a hot plate at 150 ° C., and the silicone layer was peeled off from the nickel mold. As a result, a silicone rubber sheet (protective sheet (B)) having a plurality of protrusions with a bottom width of 30 μm and a height of 35 μm was obtained. In this protective sheet (B), the arrangement of the plurality of protrusions was radial from the virtual center, and the occupied area (area ratio of the bottom surface of the protrusion to the total surface area of the base material layer) was 65%. Moreover, the refractive index of this protective sheet (B) was 1.42.

(Affixing method of Example 3)
This protective sheet (B) was affixed to the concavo-convex glass surface (light incident surface) of a CIS solar cell panel (SF150-K manufactured by Solar Frontier Co., Ltd.). On the surface of this solar cell panel, a 0.05 mm thick ionomer resin film (Mitsui-Dupont Polychemical Co., Ltd. Himiran 1702; refractive index 1.5) and a protective sheet (B) are laminated and vacuumed. The flattening material is fluidized and defoamed by heat press (70 ° C.) below, and then naturally cooled to solidify the flattening material, and the protective sheet (B) without bubbles is formed on the panel. It stuck on the solar cell panel surface by the sticking force. The solar cell device thus obtained had no bubbles at the bonding interface, the bonding strength at each interface was good, and the power generation efficiency was improved.

<Example 4>
Thermoplastic fluororesin sheet (Sumitomo 3M) extruded on a rugged glass surface of a polycrystalline silicon solar cell panel (ND-170AA manufactured by Sharp Corporation; 116.5 cm × 99 cm) into a 0.1 mm thick film as a planarizing material Dyneon PFA6525N manufactured by Co., Ltd .; refractive index 1.45) is laminated, and a thermoplastic roller is pressed onto the panel surface by moving a heating roller with a diameter of 10 cm and a width of 90 cm heated to 200 ° C. The melted and highly fluidized sheet material is buried in the concave portion of the light incident surface and the surface is flattened along the heating roller, and the temperature rapidly decreases when the heating roller passes, so the thermoplastic fluororesin sheet is solidified. To do. Furthermore, the thermoplastic fluororesin sheet could be stuck without bubbles by reciprocating the surface of the thermoplastic fluororesin sheet with a heating roller. The prism sheet of Example 1 was pasted on the flat surface in the same manner as in Example 1. The solar cell device thus obtained had no bubbles at the bonding interface, the bonding strength at each interface was good, and the power generation efficiency was improved.

<Example 5>
The prism sheet was peeled from the solar cell panel with the prism sheet produced in Example 1. At this time, only the prism sheet was peeled off, and the planarizing material was peeled off so as to remain on the solar cell panel. The solar cell panel could be easily peeled off without any prism sheet peeling residue, prism sheet damage, or flattening material surface damage. Next, the peeled prism sheet was placed in the same manner as in Example 1 so that the prism axial direction was all perpendicular to the direction of pseudo sunlight irradiation. In the solar cell device of Example 5, the amount of power generation increased and the power generation efficiency improved when rearranged in a direction suitable for the light irradiation direction, rather than the power generation amount of Example 1 in which prism sheets were randomly arranged.

<Comparative example>
The protective sheet was pressed against the solar cell panel of Example 1 so that the protective sheet (A) was bonded without using a planarizing material. However, bubbles remained in the recesses on the glass surface, and the sheet remained on the panel. It was not physically bonded, and the protective sheet detached when the panel was turned over. That is, the adhesive strength was insufficient.

  In the description of the above examples, the adhesive strength and power generation efficiency were determined as follows. Adhesive strength is as follows: Embossed cover glass for solar cells: (Solut manufactured by Nakajima Glass Industry Co., Ltd.) is used as an alternative to the glass surface of solar cells, and this embossed surface is bonded to the planarized material or protective sheet interface. A cutting knife was cut into the sheet as a trigger for peeling, and the adhesion strength between the substrate and the sheet was measured by a 90-degree peeling test (in accordance with JIS K6854-1). In addition, since the planarizing material is a thin film between the base material and the planarizing material, the PET film was adhered as a support film, and the adhesive strength was measured by pulling the PET film. When the adhesive strength between the base material and the flattening material or the protective sheet is 30 N / 15 mm or more and when peeling with material destruction, it is judged that the adhesive strength is too strong and is “bad” and less than 30 N / 15 mm and 10 N / 15 mm or more was judged as “slightly good”, and when it was less than 10 N / 15 mm, it was judged as “good” because easy peeling was possible. However, the case where there was a bubble at the adhesive interface and it was peeled upside down was judged as “bad”.

  In addition, before applying the protective sheet to the solar cell, the amount of power generated when pseudo solar light (SS-300XIM manufactured by Eihiro Seiki Co., Ltd.) is irradiated at an incident angle of 20 degrees with respect to the central part of the solar cell panel, Measurement was performed after the sheet was pasted, and it was judged as “good” when the amount of power generation after the sheet was pasted was “good”, and conversely as “bad” when the amount of power generation after pasting was small.

  The protective sheet of the present invention can be applied easily and reliably to the surface of a photoelectric conversion part such as a solar cell module, and the protective sheet can exhibit a protective function without any loss of light. Therefore, it can be optimally used for the surface of a solar cell device installed outdoors, for example.

DESCRIPTION OF SYMBOLS 1 Protective sheet 2 Base material layer 2a Each side 3 Projection part 5 Long side part 6 Short side part 7 Curved part 9 Side face 10 Side face 11 Top part 12 Ridge line 13 Bottom part 20 Photoelectric conversion part (solar cell module)
21 Solar cell 22 Sealing material 23 Translucent substrate 24 Back surface protection plate 30 Flattening material 40 Mold 40a Recess

Claims (9)

A method for attaching a protective sheet for a photoelectric conversion device, in which a photoelectric conversion part and a protective sheet are attached in a state where a light incident surface of a photoelectric conversion part that converts light energy into electricity and an adhesive surface of a transparent protective sheet are opposed to each other. There,
The photoelectric conversion portion having a concavo-convex structure on the light incident surface and the concavo-convex structure on the surface opposite to the attachment surface so that the light incident surface of the photoelectric conversion portion and the attachment surface of the protective sheet are opposed to each other with a planarizing material interposed therebetween. A step of laminating a protective sheet having a photoelectric conversion portion and a protective sheet in a deformable state of the planarizing material sandwiched between the light incident surface and the pasting surface, A process of attaching a protective sheet to the light incident surface;
A protective sheet affixing method for a photoelectric conversion device, comprising:   The method for applying a protective sheet for a photoelectric conversion device according to claim 1, wherein the protective sheet has a base material layer and a plurality of protrusions protruding from a surface opposite to the attaching surface of the base material layer. .   The refractive index of the planarizing material is equal to or lower than the refractive index of a member constituting the light incident surface of the photoelectric conversion unit, and the refractive index of the protective sheet is equal to or lower than the refractive index of the planarizing material. 3. A method for attaching a protective sheet for a photoelectric conversion device according to 2.   The method for attaching a protective sheet for a photoelectric conversion device according to claim 1, wherein the protective sheet contains a polymer resin as a main component.   The method for applying a protective sheet for a photoelectric conversion device according to claim 4, wherein the planarizing material contains the same polymer resin as the main component as the protective sheet. The planarizing material is a thermoplastic resin;
4. The protective sheet for a photoelectric conversion device according to claim 1, wherein the planarizing material is solidified by lowering a temperature of the planarizing material after sandwiching the photoelectric conversion portion and the protective sheet. Method. The planarizing material is light or thermosetting resin;
The protective sheet for a photoelectric conversion device according to claim 1, wherein the planarizing material is solidified by irradiating or heating the planarizing material after being sandwiched between the photoelectric conversion portion and the protective sheet. Pasting method.   The manufacturing method of the photoelectric conversion apparatus which has a protection sheet sticking method for photoelectric conversion apparatuses of any one of Claims 1-7. The light incident surface has a concavo-convex structure, a photoelectric conversion unit that converts light energy into electricity, and is laminated on the light incident surface side of the photoelectric conversion unit, and has a concavo-convex structure on the surface opposite to the surface that faces the light incident surface. A transparent protective sheet having
A photoelectric conversion device further comprising an intermediate layer laminated between the photoelectric conversion unit and the protective sheet and in close contact with a light incident surface of the photoelectric conversion unit and a surface facing the protective sheet.

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