JP2012028466A - Solar battery element, solar battery module, system for manufacturing solar battery module, method of manufacturing solar battery module, and roll-shape solar battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the production efficiency of a thin film solar battery modules and to prevent a short circuit between conductive substrates.SOLUTION: The solar battery module includes a plurality of belt-like solar battery elements pressed against and fixed to a surface of a flexible film and connected in series. The belt-like solar battery elements each have: a conductive substrate; at least a first electrode layer, a power generation layer and a second electrode layer, which are grown on the conductive substrate in turn; and a conductive adhesive material layer formed on a part of the backside of the conductive substrate and an insulative adhesive material layer formed on a part of the backside, where the conductive adhesive material layer is not formed. The two adjacent belt-like solar battery elements are connected in series with each other through the conductive adhesive material layer at a connection part where an end of a surface of the second electrode layer of the first belt-like solar battery element overlaps the conductive adhesive material layer of the second belt-like solar battery element and a part of the insulative adhesive material layer thereof.

Description

  The present invention relates to a solar cell element, a solar cell module, a solar cell module manufacturing apparatus, a solar cell module manufacturing method, and a roll-shaped solar cell module.

  Conventionally, a thin-film solar cell module employs a manufacturing method in which a plurality of solar cell elements are dividedly formed on a substrate by patterning and an integrated structure is formed by connecting them in series. In recent years, a thin film solar cell module in which a plurality of strip solar cells are connected in series has been reported (see Patent Document 1). In this thin-film solar cell module, a narrow band-shaped solar cell is wound in a spiral shape with an edge overlapping an insulating thin film wound around the surface of a cylindrical body, and a conductive resin is placed on the overlapping portion. After being interposed, it is manufactured by incision and separation from the cylindrical body.

Japanese Patent Laid-Open No. 02-244772

By the way, the conventional manufacturing method of a thin film solar cell module has a problem to be further improved. For example, after forming a narrow strip solar cell element, a step of winding it is necessary. 2) A certain amount of time is required for the step of winding one band-shaped solar cell element around the surface of the cylindrical body, and the productivity is low. 3) In order to manufacture one thin film solar cell module, a strip-shaped solar cell element having a certain length is required, which increases the cost. 4) Every time a single thin film solar cell module is manufactured, a step of cutting and separating from the cylindrical body is required. 5) Since the thin film solar cell module is cut to a predetermined length, the productivity in the post-process is not improved. 6) When the adhesion between the strip-shaped solar cell elements is increased, the metal substrates of the adjacent strip-shaped solar cell elements are partially in contact with each other and short-circuited so that the generated power is reduced.
An object of the present invention is to improve the manufacturing efficiency of a thin film solar cell module and to prevent a short circuit between conductive substrates.

Thus, the inventions according to the following [1] to [13] are provided.
[1] It has at least a conductive substrate, a first electrode layer sequentially stacked on the conductive substrate, a power generation layer and a second electrode layer, and is formed on a part of the back surface of the conductive substrate. And a conductive adhesive layer and an insulating adhesive layer formed on another portion of the back surface where the conductive adhesive layer is not formed.
[2] The conductive adhesive layer is formed on the back surface of the conductive substrate at a portion corresponding to a length of 1/5 or less of the width of the conductive substrate from the end of the back surface. The solar cell element according to [1] above, wherein
[3] The insulating adhesive layer is adjacent to the conductive adhesive layer, and on the back surface of the conductive substrate, from the end of the back surface to 1/5 or less of the width of the conductive substrate. The solar cell element according to [1] or [2], wherein the solar cell element is formed in a portion other than a portion corresponding to the length of the solar cell.
[4] The solar cell element according to any one of [1] to [3], wherein the power generation layer includes any one selected from a group IB element, a group IIIB element, and a group VIB element .
[5] The solar cell element according to any one of [1] to [4], wherein the power generation layer includes a Cu—In—Se based semiconductor having a chalcopyrite structure.

[6] A solar cell module including a plurality of strip solar cell elements that are pressure-bonded and fixed to the surface of a flexible film, the strip solar cell element including a conductive substrate and the conductive film At least a first electrode layer, a power generation layer, a second electrode layer sequentially formed on the conductive substrate, a conductive adhesive layer formed on a part of the back surface of the conductive substrate, and the conductive material on the back surface. An insulating adhesive layer formed on another portion where the adhesive layer is not formed, and the two adjacent band-shaped solar cell elements are formed on the surface of the second electrode layer of the first band-shaped solar cell element. In the connecting portion where the end portion and the conductive adhesive layer of the second strip solar cell element overlap with a part of the insulating adhesive layer, they are connected in series via the conductive adhesive layer. A solar cell module characterized by that.
[7] The conductive adhesive layer is formed on the back surface of the conductive substrate at a portion corresponding to a length of 1/5 or less of the width of the conductive substrate from an end of the back surface. The insulating adhesive layer is adjacent to the conductive adhesive layer and corresponds to a length of one fifth or less of the width of the conductive substrate from the end of the back surface on the back surface of the conductive substrate. The solar cell module according to the above [6], wherein the solar cell module is formed in other parts excluding the part to be performed.
[8] The above [6] or [7], wherein an end of the insulating adhesive layer opposite to the conductive adhesive layer side is pressure-bonded to the surface of the flexible film. ] The solar cell module as described in.

[9] Supply means for drawing and supplying the thin film solar cell from an unwinding roll in which a thin film solar cell having a power generation layer and an upper electrode layer formed on a conductive substrate is wound into a roll shape; Cutting means for cutting the thin-film solar cells supplied from the supply means by a blade part substantially parallel to the transport direction of the thin-film solar cells to form a plurality of strip-shaped solar cell elements, and a plurality of cut by the cutting means In the band-like solar cell element, a conductive adhesive layer is formed on an end of the back surface of the conductive substrate, and an insulating adhesive layer is formed on the other portion of the back surface adjacent to the conductive adhesive layer. Adhesive layer forming means for forming the conductive adhesive layer formed by the adhesive layer forming means, a part of the insulating adhesive layer, and the upper electrode of another adjacent band-shaped solar cell element While overlapping the surface edge of the layer A crimping means for crimping and integrally forming a flexible film from the conductive adhesive layer and the insulating adhesive layer side, and a plurality of strip-like solar cell element integrally molded by the crimping means are wound up. A solar cell module manufacturing apparatus comprising: winding means for continuously winding on a roll.
[10] The adhesive material layer forming unit prints the conductive adhesive material and the insulating adhesive material continuously or intermittently on the surface of the conductive substrate opposite to the power generation layer side. The apparatus for manufacturing a solar cell module according to [9], wherein:
[11] The crimping means includes an inclined guide roll group for inclining each of the plurality of strip-like solar cell elements formed by the cutting means at a predetermined angle with respect to the transport direction, and a sheet roll for supplying a flexible film. And a pair of pressure rolls that press-bond a plurality of the strip-shaped solar cell elements to the flexible film. The solar cell module manufacturing apparatus according to the above [9] or [10].

    [12] A method for manufacturing a solar cell module in which a plurality of strip-like solar cell elements are connected in series, and a roll-out roll of a thin film solar cell having a power generation layer and an upper electrode layer formed on a conductive substrate A supply step that is fed out from the cutting step, a cutting step in which the thin-film solar cells supplied in the supply step are cut substantially parallel to the transport direction to form a plurality of strip-shaped solar cell elements, and a plurality of cuts in the cutting step In the band-like solar cell element, a conductive adhesive layer is formed on an end of the back surface of the conductive substrate, and an insulating adhesive layer is formed on the other portion of the back surface adjacent to the conductive adhesive layer. The conductive adhesive layer and the insulating adhesive layer formed by the adhesive layer forming step, the plurality of the strip solar cell elements inclined with respect to the transport direction, and formed by the adhesive layer forming step Part of A crimping step in which a flexible film is crimped and integrally formed from the conductive adhesive layer and the insulating adhesive layer side while overlapping the surface end of the upper electrode layer of another adjacent band-shaped solar cell element And a winding step of continuously winding the connection body of the plurality of strip-shaped solar cell elements integrally formed by the crimping step onto a winding roll.

    [13] A rolled solar cell module, wherein the solar cell module manufactured by the method for manufacturing a solar cell module according to [12] is wound around a winding roll.

According to the present invention, the manufacturing efficiency of the thin-film solar cell module is improved as compared with the conventional manufacturing method.
Specifically, 1) After a thin film solar cell is cut into a plurality of narrow strip-shaped solar cell elements, a part of the width direction is overlapped, and the thin film solar cell can be pressure-bonded to an adhesive sheet without being wound on a reel. 2) The integrated module can be manufactured at a speed about 100 times that of the manufacturing method using one tape-like solar cell. 3) Compared with the manufacturing method using one tape-like solar cell, the amount of scrap material which becomes unnecessary in manufacturing is reduced. 4) Compared with the manufacturing method in which one tape-like solar cell is wound around a roll to which an adhesive sheet is attached, there is no need for a step of once removing the integrated module wound around the surface of the cylindrical body from the cylindrical body. The thin film solar cell module can be manufactured. 5) The long thin film solar cell module obtained by the present invention can be handled as a roll shape wound on a winding roll, and, for example, operability in a subsequent process such as bonding with tempered glass is improved. The 6) Even when the adhesiveness between narrow strip solar cells increases, it is possible to prevent a short circuit between the conductive substrates.

It is a figure explaining an example of the solar cell element with which this Embodiment is applied. It is a figure explaining an example of the solar cell module to which this Embodiment is applied. It is a schematic sectional drawing explaining an example of the manufacturing apparatus of the solar cell module with which this Embodiment is applied. It is a schematic perspective view explaining a mode that a web-like thin film type solar cell is cut. It is a figure explaining an inclination guide roll group.

  Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention. The drawings used are for explaining the present embodiment and do not represent the actual size.

First, the solar cell element, the solar cell module, and the manufacturing method of the solar cell module to which the present embodiment is applied can be applied when using a solar cell generally classified as a thin film solar cell. Examples of such a thin film solar cell include a thin film silicon type solar cell using hydrogenated amorphous silicon, a HIT solar cell combining amorphous and single crystal silicon, and a dye sensitized solar having a semiconductor layer carrying a sensitizing dye. Examples thereof include a battery and a compound solar battery using a compound semiconductor.
Among these, examples of the compound solar cell include a GaAs-based solar cell, a CIS-based (chalcopyrite) solar cell, a Cu ₂ ZnSnS ₄ (CZTS) solar cell, and a CdTe-CdS-based solar cell.

In particular, a CIS (chalcopyrite) solar cell is a IB-IIIB-VIB group called a chalcopyrite system made of Cu, In, Ga, Al, Se, S, etc., instead of silicon, as a material of the light absorption layer. Use compounds. Typical examples include Cu (In, Ga) Se ₂ , Cu (In, Ga) (Se, S) ₂ , CuInS _{2 and the} like. These are abbreviated as CIGS, CIGSS, and CIS, respectively.
CIS-based (chalcopyrite-based) solar cells have abundant manufacturing methods and combinations of materials, and are polycrystalline, so that they are suitable for large area and mass production, and flexible products are easily obtained. Hereinafter, a CIS type (chalcopyrite) solar cell will be described as an example, and an embodiment will be described.

<Strip solar cell element>
FIG. 1 is a diagram illustrating an example of a solar cell element to which the present embodiment is applied.
A band-shaped solar cell element 200 as an example of the solar cell element shown in FIG. 1 includes a metal substrate 202 as a conductive substrate having a width W ₀ , and a back electrode as a first electrode layer sequentially stacked on the metal substrate 202. The layer 203 includes a semiconductor layer 204 as a power generation layer, and a transparent electrode layer 205 as a second electrode layer. Further, an adhesive layer 201 made of an adhesive is formed on the back side of the surface of the metal substrate 202 on which the back electrode layer 203 is provided. The adhesive layer 201 adheres the ends of the adjacent strip-like solar cell elements 200 to each other in a solar cell module 400 (see FIG. 2) described later, and the flexible film 300 (see FIG. 2) and the solar cell module together. Used when adhering to 400.
Each configuration will be described below.

(Adhesive layer 201)
The adhesive layer 201 formed on the back side of the metal substrate 202 is composed of a conductive adhesive layer 201a containing a conductive material and an insulating adhesive layer 201b containing an insulating material. As shown in FIG. 1, the conductive adhesive layer 201 a is formed in the width W <b> 1 portion on the end side of the back surface of the metal substrate 202. The insulating adhesive layer 201b is formed in another portion adjacent to the conductive adhesive layer 201a and on the back surface of the metal substrate 202 where the conductive adhesive layer 201a is not formed, and together with the conductive adhesive layer 201a. The adhesive layer 201 is configured.

In FIG. 1, the portion of the width W2 from the end of the back surface of the metal substrate 202 is the surface of the transparent electrode layer 205 of the adjacent strip-shaped solar cell element 200 in the solar cell module 400 (see FIG. 2), as will be described later. This is a connecting portion 210 (see FIG. 2) where the end portion and the back end portion of the metal substrate 202 are overlapped and joined. As shown in FIG. 1, the width W <b> 1 where the conductive adhesive layer 201 a is formed is narrower than the width W <b> 2 of the connection portion 210. That is, the connection part 210 includes a conductive adhesive layer 201a and a part of the insulating adhesive layer 201b.
The width W ₀ of the metal substrate 202, the width W1 where the conductive adhesive layer 201a is formed, and the width W2 of the connecting portion 210 will be described later.

  Here, as an adhesive constituting the conductive adhesive layer 201a, for example, a conductive paste can be cited. The conductive paste usually uses a resin such as a thermoplastic polyester resin, an acrylic resin, or an epoxy resin as a binder, and a fine metal powder such as silver, copper, or aluminum or a conductive fine powder such as carbon black is added thereto. It is defined as those prepared by dissolving and dispersing these binders and conductive fine particles in various organic solvents. As the metal fine powder, for example, a composite metal powder in which a part of the surface of copper particles, nickel particles, aluminum particles or the like is coated with another metal such as silver or gold is also used. Among them, for silver, for example, particulate silver compounds such as first silver oxide, second silver oxide, silver carbonate, silver acetate, and acetylacetone silver complex are preferable. As such a conductive paste, a conventionally known paste that is commercially available can be used. In the present embodiment, for example, Dotite D-500 manufactured by Fujikura Kasei Co., Ltd. is used.

Examples of the adhesive constituting the insulating adhesive layer 201b include an insulating paste. Examples of the insulating paste include glass paste in which an organic binder such as glass powder and ultraviolet curable resin and a solvent are added; ceramic paste in which ceramic powder, an organic binder and a solvent are added, and the like. Examples of the glass powder in the glass paste include SiO ₂ —BaO—Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ system, and SiO ₂ —Al ₂ O. Examples include ₃ -alkali metal oxide systems, and compositions in which alkali metal oxides, ZnO, PbO, Pb, ZrO ₂ , TiO _{2 and the} like are blended with these systems. Bi ₂ O ₃ , SiO ₂ , B ₂ O ₃ , ZrO ₂ , Al ₂ O ₃ , ZnO, TiO ₂ and CaO, MgO, SrO, BaO and the like mixed with a predetermined composition ratio are mixed with lead-free glass. Etc.

Examples of the ceramic powder in the ceramic paste include Al ₂ O ₃ , SiO ₂ , forsterite, cordierite, mullite, AlN, Si ₃ N ₄ , SiC, MgTiO ₃ , and CaTiO ₃ . Furthermore, ceramic materials obtained by firing a mixture of metal oxides containing at least SiO ₂ and an alkaline earth metal oxide such as BaO, CaO, SrO, MgO at 1,100 ° C. or lower can be used.
Examples of the organic binder include an oligomer or a polymer having at least one unsaturated bond. Specific examples include polyester acrylate, polyester methacrylate, epoxy acrylate, and epoxy methacrylate.
Examples of the organic solvent include ethyl carbitol acetate, butyl carbitol acetate, butyl cellosolve, and 3-methoxybutyl acetate. As such an insulating paste, a conventionally known paste that is commercially available can be used.

(Metal substrate 202)
Examples of the conductive material constituting the metal substrate 202 of the belt-like solar cell element 200 include stainless steel plates such as SUS304 and SUS430, carbon steel, and the like. Examples of the conductive material containing iron (Fe) element include a Ni—Fe base alloy plate, a Ni—Cr—Fe base alloy plate, and a Ni—Co—Fe base alloy plate in addition to the stainless steel plate. In the present embodiment, the thickness of the metal substrate 202 is in the range of 0.02 mm to 0.1 mm, and is preferably selected as appropriate from the range of 0.03 mm to 0.06 mm.

(Back electrode layer 203)
The material constituting the back electrode layer 203 as the first electrode layer of the strip solar cell element 200 is preferably a metal, for example, at least one selected from Mo, Ti, Cr, Al, Ag, Au, Cu and Pt. One metal or an alloy thereof. In this embodiment, the back electrode layer 203 is a metal thin film having a thickness of about 0.3 μm. The back electrode layer 203 is formed on a predetermined substrate by, for example, a vapor deposition method, a sputtering method, a CVD method (Chemical Vapor Deposition) or the like, and then dividedly formed by patterning as will be described later. .

(Semiconductor layer 204)
Examples of the semiconductor constituting the semiconductor layer 204 as the power generation layer of the band-shaped solar cell element 200 include chalcopyrite type compound semiconductors containing elements from the IB group, IIIB group, and VIB group of the periodic table. In this embodiment, the semiconductor layer 204 is preferably formed using a Cu—In—Se semiconductor material having a chalcopyrite structure including copper (Cu), indium (In), and selenium (Se). In this embodiment, the thickness of the semiconductor layer 204 is in the range of 0.3 μm to 5 μm.

(Transparent electrode layer 205)
Metallic material constituting the transparent electrode layer 205 as a second electrode layer of the strip-like solar cell element 200 is not particularly limited, for example, ITO prepared by adding Sn as a dopant to _{In 2 O 3 (Indium Tin Oxide} ) oxide, such as Indium-based metal materials; tin oxide-based metal materials such as SnO ₂ with dopant added; AZO with Zn added to Al as a dopant, GZO with Zn added as a Ga dopant, ZnO with IZO added with In as a dopant, etc. Examples include zinc oxide-based metal materials. In this embodiment, it is preferable to use a metal material containing at least one selected from ITO, SnO ₂ , and ZnO and form the film by sputtering or evaporation. The thickness of the transparent electrode layer 205 is about 0.6 μm in the present embodiment.

In this embodiment mode, a buffer layer as a dielectric layer may be provided between the semiconductor layer 204 and the transparent electrode layer 205. In this case, the material constituting the buffer layer is not particularly limited, in the present embodiment, it is preferable to use a InS 3, sulfides such as _ZnS. By providing a buffer layer between the semiconductor layer 204 and the transparent electrode layer 205, defects generated at the interface between the semiconductor layer 204 and the transparent electrode layer 205 tend to be suppressed.

The back electrode layer 203 is usually formed continuously by sputtering on a metal substrate 202 made of, for example, a metal film or the like. Subsequently, the semiconductor layer 204 is formed on the back electrode layer 203, and then, A transparent electrode layer 205 is formed on the semiconductor layer 204 and prepared.
In this embodiment mode, the semiconductor layer 204 is preferably formed by stacking a plurality of p-type semiconductor formation precursor layers and n-type semiconductor formation precursor layers. That is, in this embodiment, a Cu-In-Se-based semiconductor material is used as the compound semiconductor, and a precursor for forming a p-type semiconductor composed of a mixture of Cu and Se that can easily form a p-type semiconductor on the back electrode layer 203 side. It is preferable to form a body layer, and then form a precursor layer for forming an n-type semiconductor made of a mixture of In and Se that easily forms an n-type semiconductor on the transparent electrode layer 205 side. The p-type semiconductor forming precursor layer and the n-type semiconductor forming precursor layer melt and diffuse to each other in the heat treatment process, thereby generating a semiconductor layer 204 made of a semiconductor having good crystallinity, and a pn junction. Can be formed.

<Solar cell module>
FIG. 2 is a diagram illustrating an example of a solar cell module to which the present embodiment is applied.
FIG. 2 is a schematic cross-sectional view of the solar cell module 400 taken along the line 2-2 in FIG. As shown in FIG. 2, the solar cell module 400 includes a flexible film 300 and a plurality of strip-shaped solar cell elements 200 (200 _i , 200 _{i + 1} , 200) that are pressure-bonded and fixed on the flexible film 300 and connected in series. 200 _{i + 2} ,...).
As described above with reference to FIG. 1, the plurality of strip-shaped solar cell elements 200 are each formed on the metal substrate 202 (202 _i , 202 _{i + 1} ,...) Sequentially in order of the back electrode layer 203 (203 _i , 203 _{i + 1} ,..., a semiconductor layer 204 (204 _i , 204 _{i + 1} ,...) and a transparent electrode layer 205 (205 _i , 205 _{i + 1} ,...). , Conductive adhesive layer 201a (201a _i , 201a _{i + 1} ,...) And insulating adhesive layer 201b (201b _i , 201b _{i + 1} ,...) Are provided.

As shown in FIG. 2, the plurality of strip-shaped solar cell elements 200 includes two adjacent strip-shaped solar cell elements 200 _i , 200 _{i + 1} , and surface edges of the transparent electrode layer 205 _i of the first strip-shaped solar cell element 200 _i. And the conductive adhesive layer 201a _{i + 1} and the insulating adhesive layer 201b _{i + 1} provided on the back side of the metal substrate 202 _{i + 1} of the second strip solar cell element 200 _{i + 1} overlap, and this part has a width W2. The connecting portion 210 is formed. Thereby, two adjacent strip-shaped solar cell elements 200 _i and 200 _{i + 1} are connected in series via the conductive adhesive layer 201 a _{i + 1} of the connection part 210. A plurality of narrow strip-shaped solar cell elements 200 are connected in series via the conductive adhesive layer 201a present in the connection portion 210, and a wide solar cell module 400 is formed.
Further, the insulating adhesive material layers 201b _i and 201b _{i + 1} are each fixed by pressure to the surface of the flexible film 300, and the plurality of strip-like solar cell elements 200 are fixed on the flexible film 300.

The width W ₀ (corresponding to the width of the metal substrate 202 in the present embodiment: refer to FIG. 1) of one strip-shaped solar cell element 200 constituting the solar cell module 400 is not particularly limited, but this embodiment Then, it is the range of 4 mm-30 mm. When the width W ₀ is excessively wide, the number of strip-shaped solar cell elements 200 to be used decreases, but the series resistance component tends to increase.

As shown in FIG. 2, the conductive adhesive layer 201 a is formed in the range of the width W <b> 1 from the end of the back surface of the metal substrate 202. The width W1 of the conductive adhesive layer 201a is not particularly limited. In the present embodiment, it is usually in the range of 0.5 mm to 2 mm. In general, since the conductive adhesive is more expensive than the insulating adhesive, if the width W1 of the conductive adhesive layer 201a is excessively large, it causes a significant cost increase. Moreover, since the electrical resistance between the strip | belt-shaped solar cell elements will become large when the width W1 of the electroconductive adhesive material layer 201a becomes too small, there exists a tendency for the electric power generation performance of a solar cell to deteriorate. In this embodiment, the width W1 of the conductive adhesive layer 201a is formed is equivalent to less than one length of 5 minutes of the width W ₀ of the metal substrate 202.
In the present embodiment, the conductive adhesive layer 201a _{i + 1} of the second strip solar cell element 200 _{i + 1} is connected to the connecting section 210 that connects two adjacent strip solar cell elements (200 _i , 200 _{i + 1} ) in series. In the back surface of the metal substrate 202 _{i + 1} , it is preferable that the metal substrate 202 _{i + 1} is provided at an end closest to the adjacent first strip solar cell element 200 _i .

The insulating adhesive layer 201b is formed on the back surface of the metal substrate 202 at other portions except the width W1 portion from the end of the metal substrate 202 on which the insulating adhesive layer 201b is formed.
As shown in FIG. 2, the insulating adhesive layer 201b _{i + 1} is a part of the back surface of the metal substrate 202 _{i + 1} , and a part of the insulating adhesive layer 201b _{i + 1} exists in the connection part 201 and is adjacent to the two conductive solar layers 201a _{i + 1.} Battery elements (200 _i , 200 _{i + 1} ) are joined. Further, the remaining part of the insulating adhesive layer 201b _{i + 1} is formed so as to cover the other part of the back surface of the metal substrate 202 _{i + 1} , and is the end opposite to the first strip solar cell element 200 _i. , The second strip solar cell element 200 _{i + 1} and the flexible film 300 are joined.

  Although the width W2 of the connection part 210 is not specifically limited, In this Embodiment, it is the range of 0.05 mm-1 mm. When the width W2 is reasonably wide, the interconnect resistance at the connection portion 210 is reduced, and accuracy is not required when the strip solar cell elements 200 are overlapped. However, since the connecting portion 210 does not contribute to power generation, the material cost per unit power generation tends to increase. Further, since the weight of the entire solar cell module 400 also increases, it is preferable to make the width W2 of the connecting portion 210 as narrow as possible in order to reduce the weight.

A part of the insulating adhesive material layer 201b _{i + 1} exists in the connection part 210 and is formed so as to cover the other part of the back surface of the metal substrate 202 _{i + 1} , so that two adjacent strip-like solar cell elements ( 200 _i, in _{200 i + 1),} and the metal substrate 202 _i of the first strip-like solar cell element 200 _i, a short circuit between the elements generated by the second belt-like solar cell element _{200 i + 1} of the contact between the metal substrate _{202 i + 1} is prevented The

  In this embodiment, the material of the flexible film 300 is desirably a plastic film having excellent weather resistance and moisture resistance, and is not particularly limited. Specifically, for example, a general solar cell backsheet in which a fluororesin material is coated on polyethylene terephthalate (PET) as a base material, a laminate type film in which a plurality of films are laminated, and the like can be given. Here, as a film used for a laminate type film, a PET film, an ethylene vinyl acetate (EVA) film, a polyvinyl fluoride (PVF) film, a polyvinylidene fluoride (PVDF) film, etc. are mentioned, for example.

In the present embodiment, a transparent front sheet can be pressure-bonded to the surface side of the solar cell module 400 (that is, the transparent electrode layer 205 side) (not shown). In this case, it is important to use a plastic film having excellent weather resistance and moisture resistance as the front sheet. Furthermore, since it arrange | positions on the surface of the solar cell module 400 as a front sheet | seat, transparency, impact resistance, and antifouling property become important. Specific examples of the front sheet include, for example, a laminate type film in which a plurality of films excellent in these performances are laminated. Here, examples of the plurality of laminated films include a polyvinyl fluoride (PVF) film and a polyvinylidene fluoride (PVDF) film. In order to improve moisture resistance, an inorganic material thin film such as SiO ₂ or a glass thin film may be vacuum-formed in a laminate film.

  Electrons present in the transparent electrode layer 205 on the band-shaped solar cell element 200 are transmitted to the adjacent band-shaped solar cell element 200 by contacting the back electrode layer 203 of another adjacent band-shaped solar cell element 200. Here, since the electrical resistance of the transparent electrode layer 205 is usually several orders of magnitude higher than the electrical resistance of the back electrode layer 203, before the electrons are transmitted to the adjacent strip-like solar cell element 200, the transparent electrode layer 205 There is a possibility that it will be lost. In such a case, for example, a method of providing a current collecting electrode on the belt-like solar cell element 200 is effective.

<Solar cell module manufacturing equipment>
FIG. 3 is a schematic cross-sectional view illustrating an example of a solar cell module manufacturing apparatus to which the present embodiment is applied.
The solar cell module manufacturing apparatus shown in FIG. 3 includes a supply unit I that supplies a web-shaped thin film solar cell 100 and a thin strip solar cell 100 conveyed from the supply unit I. A cutting part II to be cut into 200, an adhesive layer forming part III to form an adhesive layer on the back surface of the metal substrate 202 (see FIG. 1) of the plurality of strip-like solar cell elements 200 cut into the cutting part II, and bonding The end portions of the plurality of strip-shaped solar cell elements 200 on which the material layers are formed are overlapped, and the flexible film 300 is crimped and integrally molded, and the flexible film 300 is integrally molded with the crimped portion IV. In addition, the solar cell module 400 is constituted by a winding unit V that continuously winds up the solar cell module 400.

  Here, in the thin-film solar cell 100 used in the present embodiment, a semiconductor layer constituting a power generation layer is generally formed on a sheet-like metal substrate that becomes a conductive substrate such as a stainless steel substrate. An extensive web with a transparent electrode layer and the like formed thereon. The full width dimension of the web-like thin film solar cell 100 is 50 cm to 100 cm, and the length is not particularly limited, but is usually 10,000 m or less.

  The supply unit I serves as supply means, an unwinding roll 11 in which a web-shaped thin film solar cell 100 is wound in a roll shape, and transport rolls 12 and 13 that pull out and transport the thin film solar cell 100 from the unwinding roll 11. And have. In the present embodiment, the web-like thin film solar cell 100 is drawn from the unwinding roll 11 that rotates in the direction of arrow A so that the back surface of the metal substrate 202 (see FIG. 1) faces upward in the drawing. It is conveyed in the direction of arrow B and supplied to the cutting unit II.

  The cutting part II cuts the thin film solar cell 100 into a plurality of narrow strip solar cell elements 200. As a cutting means, it has the blade part (slitter) 20 comprised from the rotary blade 21 and the rotation receiving blade 22. As shown in FIG.

  The adhesive material layer forming section III includes an adhesive material printing unit 50. Adhesive printing unit 50 conveys a plurality of strip solar cell elements 200 cut by cutting section II by transport roll 51, and on the back surface of metal substrate 202 (see FIG. 1) of each strip solar cell element 200, A conductive adhesive and an insulating adhesive are printed continuously or intermittently in parallel with the transport direction (arrow B direction).

  The crimping part IV serves as a crimping means, an inclined guide roll group 30 for tilting each of the plurality of narrow strip solar cell elements 200 formed by the blade part 20 at a predetermined angle with respect to the transport direction, and a flexible film. A sheet roll 31 for supplying 300, and a pressure-bonding roll 32 including a pair of rolls 321 and 322 that press-bond a plurality of narrow strip-shaped solar cells to the flexible film 300 and integrally form them.

  The winding part V has a winding roll 40 that continuously winds up the solar cell module 400 integrally formed with the flexible film 300 at the crimping part IV as a winding means. The winding roll 40 rotates in the direction of arrow C and continuously winds the conveyed solar cell module 400.

FIG. 4 is a schematic perspective view for explaining a state in which the web-like thin film solar cell 100 is cut. 4 does not show the adhesive printing unit 50, the sheet roll 31, and the take-up roll 40 in FIG.
As shown in FIG. 4, the blade part 20 (slitter) of the cutting part II for cutting the web-like thin film solar cell 100 drawn out from the unwinding roll 11 is a plurality of thin disk-like rotary blades that are driven to rotate. 21 and a plurality of rotary receiving blades 22 formed in a roller shape as receiving blades. The wide thin film solar cell 100 is cut into a plurality of narrow strip solar cell elements 200 when passing between the pair of upper and lower rotary blades 21 and the rotary receiving blade 22. Although the space | interval (pitch) of the blade | wing which comprises the rotary blade 21 and the rotary receiving blade 22 is not specifically limited, In this Embodiment, it selects suitably in the range of 4 mm-10 mm.

The inclined guide roll group 30 of the crimping part IV inclines a plurality of narrow strip-shaped solar cell elements 200 at a predetermined angle with respect to the transport direction, and side edges (in the width direction between adjacent strip-shaped solar cell elements 200). The interval is narrowed so that part of the edges overlap.
The pressure roll 32 is a flexible film supplied from a plurality of strip-shaped solar cell elements 200 in which a part of edges (edges) in the width direction is overlapped by the inclined guide roll group 30 and a sheet roll 31 (not shown). When 300 (not shown) is passed between a pair of rolls 321 and 322 (see FIG. 3), they are pressure-bonded and integrated.

(Inclined guide roll group 30)
FIG. 5 is a diagram illustrating the inclined guide roll group 30. FIG. 5A is a schematic diagram of the inclined guide roll group 30. FIG.5 (b) is the schematic which looked at the part of the inclination guide roll group 30 in FIG. 4 from the direction of the arrow 5b.
As shown in FIG. 5A, the inclined guide roll group 30 includes a common support shaft 304, a plurality of rotation shafts 303 formed at a predetermined angle with respect to the support shaft 304, and each rotation shaft 303. And a plurality of inclined guide rolls 301 (301 ₁ ,... 301 _i ) respectively attached to The inclined guide roll 301 (301 ₁ ,... 301 _i ) is provided with guides 302 at both ends. A bearing or the like may be provided inside the inclined guide roll 301.

As shown in FIG. 5 (b), the plurality of strip-shaped solar cell elements 200 (200 ₁ ,... 200 _i ) cut by the blade part 20 (see FIG. 3) are inclined guide rolls of the inclined guide roll group 30. By 301, while each inclining with a predetermined angle with respect to a conveyance direction, the space | interval of adjacent strip | belt-shaped solar cell elements 200 is narrowed. And the connection part 210 in which a part of side edge part mutually overlaps is formed.
A part of the conductive adhesive layer 201a and the insulating adhesive layer 201b exists in the connection part 210 where the side edges of the adjacent strip-shaped solar cell elements 200 overlap.
Adjacent belt-like solar cell elements 200 are connected in series by a conductive adhesive layer 201a and are joined by a part of the conductive adhesive layer 201a and the insulating adhesive layer 201b.

<Method for Manufacturing Solar Cell Module 400>
Next, a method for manufacturing a solar cell module using a solar cell module manufacturing apparatus to which the present embodiment is applied (see FIGS. 3, 4 and 5) will be described.
First, the thin film solar cell 100 is unwound from the unwinding roll 11 wound in a roll shape, and supplied to the blade part 20 (supplying step). As described above, in this embodiment, the web-like thin film solar cell 100 is wound in the direction of arrow A so that the back surface of the metal substrate 202 (see FIG. 1) faces upward in FIG. It is pulled out from the take-out roll 11, conveyed in the direction of arrow B, and supplied to the cutting unit II.

  Next, when the thin film solar cell supplied from the unwinding roll 11 passes between the pair of upper and lower rotary blades 21 and the rotary receiving blade 22 in the blade part 20, the thin film solar cell is cut substantially parallel to the conveying direction. A plurality of narrow strip solar cell elements 200 are formed (cutting step).

  Subsequently, the plurality of narrow strip solar cell elements 200 cut by the blade portion 20 substantially in parallel with the conveying direction are respectively bonded to the respective metal substrates 202 of the strip solar cell elements 200 by the adhesive printing unit 50 (see FIG. 1). ) Is formed with a conductive adhesive layer 201a (see FIG. 1) and an insulating adhesive layer 201b (see FIG. 1) (adhesive layer forming step). The adhesive is printed continuously or intermittently by the adhesive printing unit 50.

Subsequently, each of the formed strip-shaped solar cell elements 200 is inclined at a predetermined angle with respect to the transport direction by the inclined guide roll group 30. The band-shaped solar cell elements 200 that have passed through the inclined guide roll group 30 are narrowed in the interval between the adjacent band-shaped solar cell elements 200, and the connection portions 210 (210 ₁ ,... 210 _i where the side edge portions overlap each other. ) Is formed. Next, the plurality of strip-shaped solar cell elements 200 with a part of the side edges overlapped with the flexible film 300 supplied from the sheet roll 31 are integrally formed by pressure bonding with the pressure-bonding roll 32, and the solar cell module 400 is formed. Form (crimping step). The solar cell module 400 is formed as a connection body in which a plurality of strip-shaped solar cell elements 200 are connected in series.

Finally, the solar cell module 400 integrally formed with the flexible film 300 is continuously wound around a winding roll (winding step).
Although not shown, the solar cell module 400 manufactured in the present embodiment is obtained as a rolled solar cell module wound around the take-up roll 40. Thereby, the solar cell module 400 integrated by connecting a plurality of narrow strip solar cell elements 200 in series can be handled as a roll product. Although the roll width | variety of a roll-shaped solar cell module is not specifically limited, In this Embodiment, it is the range of 10 cm-100 cm. Although the length of the solar cell module 400 wound around the winding roll 40 is not particularly limited, in the present embodiment, it is in the range of 100 m to 10,000 m.

In addition, the above description is only an example for demonstrating embodiment of this invention, and this invention is not limited to this embodiment.
The present invention can be applied to a photovoltaic device including a semiconductor layer composed of a plurality of elements and two electrode layers sandwiching the semiconductor layer, and a method for manufacturing a photovoltaic device having such a structure. For example, a III-V group semiconductor typified by a Cd-Te system, an I-III-VI group semiconductor typified by a Cu-In-Se system, and an I-II typified by a Cu-Zn-Sn-S system compound The present invention can also be applied to an IV group semiconductor composed of two or more elements such as an -IV-VI group semiconductor, an II-IV-V group semiconductor, and a Si-Ge group.

DESCRIPTION OF SYMBOLS 11 ... Unwinding roll, 12, 13, 51 ... Conveyance roll, 20 ... Blade part (slitter), 21 ... Rotary blade, 22 ... Rotation receiving blade, 30 ... Inclined guide roll group, 31 ... Sheet roll, 32 ... Crimp roll 40 ... take-up roll, 50 ... adhesive printing unit, 100 ... thin film solar cell, 200 ... strip solar cell element, 201 ... adhesive layer, 201a ... conductive adhesive layer, 201b ... insulating adhesive layer, DESCRIPTION OF SYMBOLS 202 ... Metal substrate, 203 ... Back electrode layer, 204 ... Semiconductor layer, 205 ... Transparent electrode layer, 210 ... Connection part, 300 ... Flexible film, 301 ... Inclined guide roll, 400 ... Solar cell module, I ... Supply part II ... Cutting part, III ... Adhesive layer forming part, IV ... Press-bonding part, V ... Winding part

Claims (13)

A conductive substrate;
Having at least a first electrode layer, a power generation layer and a second electrode layer laminated in order on the conductive substrate;
A conductive adhesive layer formed on a part of the back surface of the conductive substrate, and an insulating adhesive layer formed on another part of the back surface where the conductive adhesive layer is not formed. A characteristic solar cell element.   The conductive adhesive layer is formed on the back surface of the conductive substrate at a portion corresponding to a length equal to or less than one fifth of the width of the conductive substrate from an end of the back surface. The solar cell element according to claim 1.   The insulating adhesive layer is adjacent to the conductive adhesive layer and has a length of one fifth or less of the width of the conductive substrate from the end of the back surface on the back surface of the conductive substrate. The solar cell element according to claim 1, wherein the solar cell element is formed in a portion other than the portion corresponding to.   4. The solar cell element according to claim 1, wherein the power generation layer includes any one selected from a group IB element, a group IIIB element, and a group VIB element. 5.   5. The solar cell element according to claim 1, wherein the power generation layer includes a Cu—In—Se based semiconductor having a chalcopyrite structure. A solar cell module composed of a plurality of strip-shaped solar cell elements that are pressure-bonded and fixed to the surface of a flexible film, and connected in series,
The band-shaped solar cell element is formed on a conductive substrate, at least a first electrode layer, a power generation layer, a second electrode layer, and a part of the back surface of the conductive substrate, which are sequentially formed on the conductive substrate. A conductive adhesive layer, and an insulating adhesive layer formed on another portion of the back surface where the conductive adhesive layer is not formed,
Two adjacent band-shaped solar cell elements are provided on the end of the surface of the second electrode layer of the first band-shaped solar cell element and on the back side of the conductive substrate of the second band-shaped solar cell element. A solar cell module, wherein the conductive adhesive layer and a part of the insulating adhesive material layer are connected in series via the conductive adhesive material layer at a connection portion where the conductive adhesive material layer and a part of the insulating adhesive material layer overlap.   The conductive adhesive layer is formed on the back surface of the conductive substrate at a portion corresponding to a length equal to or less than one fifth of the width of the conductive substrate from an end of the back surface. The material layer is adjacent to the conductive adhesive layer, and on the back surface of the conductive substrate, a portion corresponding to a length equal to or less than one fifth of the width of the conductive substrate from the end of the back surface. The solar cell module according to claim 6, wherein the solar cell module is formed in a portion other than the portion.   8. The solar cell according to claim 6, wherein an end of the insulating adhesive layer opposite to the conductive adhesive layer side is pressure-bonded to the surface of the flexible film. module. A supply means for drawing and supplying the thin film solar cell from an unwinding roll in which a thin film solar cell having a power generation layer and an upper electrode layer formed on a conductive substrate is wound in a roll shape;
Cutting means for cutting the thin-film solar cell supplied from the supply means by a blade part substantially parallel to the transport direction of the thin-film solar cell to form a plurality of strip-shaped solar cell elements;
In the plurality of strip-like solar cell elements cut by the cutting means, a conductive adhesive layer is formed on an end portion of the back surface of the conductive substrate, and the back surface of the back surface is adjacent to the conductive adhesive layer. An adhesive layer forming means for forming an insulating adhesive layer on the portion;
While superposing the conductive adhesive layer formed by the adhesive layer forming means and a part of the insulating adhesive layer, and the surface end of the upper electrode layer of another adjacent band-shaped solar cell element, A crimping means for crimping and integrally forming a flexible film from the conductive adhesive layer and the insulating adhesive layer side;
A winding means for continuously winding the connection body of the plurality of strip-like solar cell elements integrally formed by the pressure-bonding means on a winding roll;
An apparatus for manufacturing a solar cell module, comprising:   The adhesive layer forming means has an adhesive printing unit that continuously or intermittently prints a conductive adhesive and an insulating adhesive on a surface of the conductive substrate opposite to the power generation layer. The apparatus for manufacturing a solar cell module according to claim 9.   The crimping means includes an inclined guide roll group for inclining each of the plurality of strip-like solar cell elements formed by the cutting means at a predetermined angle with respect to the transport direction, a sheet roll for supplying a flexible film, and a plurality of The solar cell module manufacturing apparatus according to claim 9, further comprising: a pair of pressure rolls that press-bond the band-shaped solar cell element to the flexible film. A method of manufacturing a solar cell module in which a plurality of strip-like solar cell elements are connected in series,
A supply step of feeding a thin film solar cell having a power generation layer and an upper electrode layer formed on a conductive substrate from an unwinding roll;
A cutting step of cutting the thin-film solar cell supplied by the supplying step substantially parallel to the transport direction to form a plurality of strip-shaped solar cell elements;
In the plurality of strip-shaped solar cell elements cut by the cutting step, a conductive adhesive layer is formed on an end portion of the back surface of the conductive substrate, and the back surface of the conductive substrate is adjacent to the conductive adhesive layer. An adhesive layer forming step of forming an insulating adhesive layer on the part of
The plurality of the strip-shaped solar cell elements are inclined with respect to the transport direction, and the conductive adhesive layer formed by the adhesive layer forming step and a part of the insulating adhesive layer are adjacent to another strip. A pressure bonding step in which a flexible film is pressure-bonded and integrally formed from the conductive adhesive layer and the insulating adhesive layer side while overlapping the surface end of the upper electrode layer of the solar cell element;
A winding step of continuously winding the connection body of the plurality of strip-like solar cell elements integrally formed by the crimping step onto a winding roll;
The manufacturing method of the solar cell module characterized by having.   A rolled solar cell module, wherein the solar cell module produced by the method for producing a solar cell module according to claim 12 is wound around a take-up roll.

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