JP5136700B2 - Thin film solar cell module - Google Patents

Description

  The present invention relates to a thin-film solar cell module, and more particularly to an electric wire structure for extracting output from an electrode formed on a thin-film solar cell to the outside of the module and a manufacturing method thereof.

  Conventionally, production of a thin film solar cell module has been performed in the following procedure. First, the several photovoltaic cell which laminated | stacked the transparent conductive layer, the photoelectric converting layer, and the back surface electrode layer in order on the translucent board | substrate is formed, and they are connected in series. Next, bus bar electrodes such as copper foil are connected to the positive and negative electrode portions at both ends of the series connection. Further, lead wires are connected to these bus bar electrodes. This lead wire is led to a terminal box provided on the back side of the light receiving surface of the solar cell module. Solder or a conductive adhesive is used for connection between the bus bar electrode and the lead wire.

  As a result, the lead wire crawls immediately above the back electrode layer of the solar battery cell. In order to prevent a short circuit, the lead wire and the solar battery cell are electrically insulated with a resin sheet or the like. Thereafter, a protective sheet is adhered on them with ethylene vinyl acetate (hereinafter EVA) to seal the module. An opening is provided in the protective sheet at the position where the terminal box is attached, and the lead wire is taken out from the opening. In order to increase moisture resistance, the protective sheet preferably has a structure in which a metal foil is sandwiched between resin films.

  Patent Document 1 shows a structure in which one end of a lead wire covered with an insulating film is connected to a bus bar electrode by soldering and the other end is taken out from an opening of a protective sheet. Covering with an insulating film ensures insulation between the lead wire and the back electrode layer and between the lead wire and the metal foil of the protective sheet. Solder-plated copper foil is used as the bus bar electrode.

  Patent Document 2 discloses a structure in which a bus bar and a lead wire are integrated. The length of the bus bar is the length protruding from one end of the substrate, the protruding portion is bent, and the bent end is taken out from the through hole (opening) of the protective sheet to the back side. An electrically insulating spacer is sandwiched between the bent portion and the cell. A rectangular copper wire or the like is used for the bus bar.

Japanese Patent Laid-Open No. 9-326497 JP 2000-286439 A

  In Patent Document 1, since one end of a lead wire extending substantially perpendicular to the bus bar electrode is bonded by solder, stress accompanying thermal expansion or contraction of the lead wire is likely to concentrate on the bonding point. With long-term use, there is a problem that the connection between the bus bar electrode and the lead wire is deteriorated and the power generation characteristics of the module are lowered. In addition, since a copper foil plated with solder is used for the bus bar electrode, there has been a problem that tin whiskers are generated on the surface during long-term use, resulting in poor insulation with adjacent cells.

  Patent Document 2 uses a flat copper wire or the like as a bus bar electrode, and sandwiches a sheet that electrically insulates the bent portion from the solar battery cell. The length and width of the sheet must be larger than the bent portion of the bus bar electrode, and a process such as bending the bus bar electrode after laying the sheet at a predetermined position is required. For this reason, there is a problem that not only a large number of members are required but also the process becomes complicated. Further, since the surface of the copper wire is exposed in the adhesive layer, there has been a problem that the component of the adhesive layer reacts with the copper wire to cause deterioration near the interface between them.

  Accordingly, the present invention aims at simplifying the process by reducing the number of members used for manufacturing, as well as making the thin film solar cell module improved in the long-term reliability of electrical connection and insulation, with respect to the above problems. To do.

  The thin-film solar battery module of the present invention includes a plurality of thin-film solar cells connected in series and an output electrode that is long in one direction at the end of the series connection; A protective member that covers the thin-film solar cell and the output electrode, and an electric wire that guides electric power from the output electrode to the outside of the protective member, and the electric wire extends in the one direction and is connected to the output electrode. A thin-film solar cell module comprising: a bus bar region; a bent region that is folded back so that a direction extending with respect to the bus bar region is changed; and a lead region that leads out of the protective member from the bent region; The electric wire is a thin coated electric wire having a wire made of a thin metal plate, and a coating thinner than the thickness of the wire made by baking an insulating paint on the surface of the wire, and the bus In the region, the coating on one surface of the electric wire is removed and the electric wire and the output electrode are electrically connected, and the other surface of the electric wire is in a state where the coating is attached, The other surface of the attached electric wire is folded back in the folding region and faces the thin-film solar cell in the lead region.

  The manufacturing method of the thin film solar cell module of the present invention includes a substrate provided with a plurality of thin film solar cells connected in series and an output electrode that is long in one direction at an end of the series connection, and is attached to the substrate. A protective member that covers the plurality of thin-film solar cells and the output electrode; and an electric wire that guides electric power from the output electrode to the outside of the protective member, and the electric wire extends in the one direction and the output A thin-film solar cell module comprising: a bus bar region connected to an electrode; a folded region that is folded back so as to change a direction extending with respect to the bus bar region; and a lead region that leads out of the protective member from the folded region. In the manufacturing method, the step of preparing the substrate, the wire made of a thin metal plate as the electric wire, and the thickness of the wire made by baking an insulating paint on the surface of the wire A step of preparing a thin coated electric wire having a coating, and in the bus bar region, removing the coating on one surface of the electric wire to electrically connect the electric wire and the output electrode, A connecting step in which the coating is attached to the other surface of the electric wire, and the other surface of the electric wire to which the coating is attached is folded back in the folding region and faces the thin film solar cell in the lead region. A step of arranging the electric wire as described above.

  According to the thin film solar cell module of the present invention, the electric wire is a thin coated electric wire having a wire made of a thin metal plate and a coating thinner than the thickness of the wire made by baking an insulating paint on the surface of the wire. In the bus bar region, the other surface opposite to the one surface connected to the output electrode is covered with a coating. Since the other surface of the electric wire covered with this film is folded back in the folding region and faces the thin film solar cell in the lead region, a thin film solar cell module with improved long-term reliability of electrical connection and insulation is obtained. The number of members used for the production can be reduced and the process can be simplified.

  According to the method for manufacturing a thin-film solar cell module of the present invention, the electric wire is a thin plate coating having a wire made of a thin metal plate and a coating thinner than the thickness of the wire made by baking an insulating paint on the surface of the wire. An electric wire is prepared, and the other surface, which is opposite to the one surface connected to the output electrode in the bus bar region, is covered with a coating. The step of forming the bent region includes a step of turning back the non-connection surface so as to face the thin film solar cell, and the other surface of the electric wire covered with the coating is turned back in the bent region, and the thin film solar cell in the lead region Therefore, it is possible to manufacture a thin film solar cell module with improved long-term reliability of electrical connection and insulation, reduce the number of members used for manufacturing, and simplify the process.

It is a perspective view explaining the board | substrate with a cell which is a component of the thin film solar cell module of Embodiment 1 of this invention. It is a perspective view which shows the decomposition | disassembly structure of the thin film solar cell module of Embodiment 1 of this invention. It is the perspective view which looked at the thin film solar cell module of Embodiment 1 of this invention from the back side. It is a top view explaining the assembly process of the thin film solar cell module of Embodiment 1 of this invention. It is a top view explaining the assembly process of the thin film solar cell module of Embodiment 1 of this invention. It is the top view which showed the electric wire of the thin film solar cell module of Embodiment 1 of this invention. It is sectional drawing which showed the electric wire of the thin film solar cell module of Embodiment 1 of this invention. It is a top view explaining the partial structure of the electric wire of the thin film solar cell module of Embodiment 1 of this invention. It is a perspective view which shows the decomposition | disassembly structure of the thin film solar cell module of Embodiment 2 of this invention. It is the perspective view which looked at the thin film solar cell module of Embodiment 2 of invention from the back side. It is a top view explaining the assembly process of the thin film solar cell module of Embodiment 2 of this invention. It is a top view explaining the assembly process of the thin film solar cell module of Embodiment 2 of this invention. It is a top view explaining the assembly process of the thin film solar cell module of Embodiment 2 of this invention. It is the fragmentary top view and sectional drawing of the thin film type solar cell module of Embodiment 3 of this invention. It is the partial top view and sectional drawing of the modification of the thin film type solar cell module of Embodiment 3 of this invention. It is the partial top view and sectional drawing of the modification of the thin film type solar cell module of Embodiment 3 of this invention. It is the fragmentary top view and sectional drawing of the thin film type solar cell module of Embodiment 4 of this invention. It is a top view explaining the assembly process of the thin film solar cell module of Embodiment 5 of this invention. It is a fragmentary sectional view of the thin film solar cell module of Embodiment 5 of the present invention.

  The thin film solar cell module and the manufacturing method thereof according to the present invention will be described with reference to the accompanying drawings. In the following drawings and description, the same components will be denoted by the same reference numerals and the description will be simplified.

<Embodiment 1. >
FIG. 1 is a perspective view for explaining a cell-attached substrate that is a component of the thin-film solar battery module according to the first embodiment. The substrate with cells 100 is a translucent and electrically insulating substrate 1, a plurality of thin film solar cells 10 formed on the substrate 1, and a plurality of thin film solar cells 10 connected in series with each other. The output electrode 21 is long in one direction. Sunlight enters from the surface of the substrate 1 opposite to the surface on which the thin film solar cells 10 are formed, passes through the substrate 1, and then is converted into electricity by the thin film solar cells 10 on the back side. The substrate 1 is made of glass or a resin material.

  The shape of the thin-film solar battery 10 of the first embodiment is a rectangular shape that is elongated in a direction parallel to one side of the rectangular substrate 1. A large number of thin-film solar cells 10 are arranged in the direction of a side that intersects one side. Adjacent thin-film solar cells 10 are electrically connected in series, and output electrodes 21 are installed at both ends thereof. The output electrode 21 has a long shape along the longitudinal direction of the thin-film solar battery cell 10. A gap is provided between the periphery of the substrate 1 and the output electrode 21 and the thin-film solar battery cell 10 for electrical insulation from the outside. Depending on the arrangement form of the thin-film solar cells 10, the positions of the output electrodes 21 do not necessarily need to be near both ends of the substrate 1, and the positions may be between the arrangements of the thin-film solar cells 10.

The thin-film solar battery 10 has a structure in which a first electrode 2, a photoelectric conversion layer 4, and a second electrode 6 are sequentially stacked on a substrate 1. The first electrode 2 is made of a transparent conductive material such as SnO ₂ , ITO (Sn-added indium oxide), ZnO, or the like. The thickness of the first electrode 2 is, for example, 0.3 to 1 micron.

  The photoelectric conversion layer 4 is made of, for example, a semiconductor film such as amorphous silicon or microcrystalline silicon. In general, a p layer, an i layer, and an n layer are stacked in the thickness direction in the photoelectric conversion layer 4. The semiconductor material of the photoelectric conversion layer 4 is not limited to silicon, but may be silicon containing germanium or carbon, or another semiconductor material such as a compound system. Alternatively, a tandem photoelectric conversion layer 4 in which a plurality of photoelectric conversion layers having different photoelectric conversion wavelengths are stacked may be used. The thickness of the photoelectric conversion layer 4 is, for example, 0.3 to 5 microns.

  The second electrode 6 is made of a metal whose main component is silver or aluminum. A material with low electrical resistance and high reflectivity is preferred. When a material having a high reflectance is used, light that has passed through the photoelectric conversion layer 4 is reflected again by the second electrode 6 toward the photoelectric conversion layer 4 and can be photoelectrically converted, so that conversion efficiency can be increased. When the photoelectric conversion layer 4 is a metal material, a layer for preventing a reaction between the semiconductor and the metal may be sandwiched between the photoelectric conversion layer 4 and the second electrode 6. The thickness of the second electrode 6 is, for example, 0.2 to 1 micron. When the light is further guided to the back side, a transparent conductive material similar to that of the first electrode 2 may be used as the material of the second electrode 6 instead of the metal.

  Adjacent thin-film solar cells 10 are separated by dividing the first electrode 2, the photoelectric conversion layer 4, and the second electrode 6 by grooves. A groove 19 in FIG. 1 indicates a groove that divides the second electrode 6. These grooves are formed by a laser scribe method or the like. Moreover, these grooves are used for serial connection of the thin-film solar cells 10. In the groove, the first electrode 2 of one thin film solar cell and the second electrode 6 of the adjacent thin film solar cell are electrically connected in series. In the first embodiment, a connection groove is formed in the photoelectric conversion layer 4 at a position where the first electrode 2 of the adjacent thin-film solar battery extends, and the second electrode 6 is buried in the groove to connect in series. It is carried out. In addition, the connection structure between cells is an example, and the serial connection structure can be variously changed.

  The width of the thin-film solar cell 10, that is, the distance between the grooves separating the cells is, for example, about 5 to 10 mm. A typical arrangement in the case of using a rectangular substrate 1 having a side of 1 m or more is one thin thin-film solar cell 10 having a width of about several millimeters and a length of about 1 m with a distance of about 5 to 10 mm from the peripheral edge. It is a shape in which a large number are arranged in parallel along the side.

  In this Embodiment 1, the part which has the same laminated structure as the thin film photovoltaic cell 10 located in the end of the thin film photovoltaic cell 10 connected in series as the output electrode 21 was used. However, if the structure shown in the figure is used, the output electrode 21 portion does not contribute to power generation. Therefore, the width of the output electrode 21 may be made narrower than the width of the thin-film solar cell 10 to reduce the area ineffective for power generation. The structure of the output electrode 21 can be variously changed. For example, the second electrode 6 on the back side of the thin-film solar cell 10 may be used as it is as one output electrode 21.

  FIG. 2 is a perspective view showing an exploded structure of the thin film solar cell module according to the first embodiment. FIG. 3 is a perspective view of the thin-film solar cell module according to Embodiment 1 viewed from the back side. FIG. 3 is a completed view in which the components of FIG. 2 are integrated. A protective member 27 that covers the plurality of thin-film solar cells 10 and the output electrode 21 is attached to the cell-attached substrate 100 by the adhesive layer 25.

  As the protective member 27, a resin sheet having low water vapor permeability was used. For example, a sheet made of polyethylene terephthalate (PET) or polyvinyl fluoride (PVF), a multilayered sheet of these sheets, or a sheet sandwiched with aluminum foil can be used. The adhesive layer 25 can be made of, for example, thermoplastic resin EVA or polyvinyl butyral (PVB).

  The electric wires 15 are connected to positive and negative output electrodes 21 located at both ends of the cell-equipped substrate 100. Since the output electrode 21 has the same laminated structure as the thin film solar cell 10 as described above, the electric wire 15 is connected to the same metal film as the second electrode 6 of the thin film solar cell 10. One end of each of the electric wires 15 passes through the opening 26 of the adhesive layer 25 and the opening 29 of the protective member 27 from the sealed inside between the substrate 1 and the protective member 27 to the outside of the protective member 27. Is issued. A terminal box 31 is attached to the back side of the protective member 27 so as to surround the opening 29. In the terminal box 31, the positive and negative electric wires 15 are electrically connected to the positive and negative external electric wires 35, respectively. Although not shown in the figure, the terminal box 31 is filled with a sealing resin such as a silicone resin. The electric power generated in the module by the external electric wire 35 is guided to an external electric device.

  As shown in FIG. 2, the electric wire 15 of the first embodiment has a structure in which the bus bar and the output lead wire are combined. The electric wire 15 is bent halfway and has a bus bar region 15a, a bent region 15t, and lead regions 15b and 15c.

  The electric wire 15 is a thin coated electric wire having a wire made of a thin metal plate and an insulating coating thinner than the thickness of the wire made by baking an insulating paint on the surface of the wire. Such a thin wire is also called a flat wire, a flat wire, or a ribbon wire because of its ribbon shape.

  The bus bar region 15 a of the electric wire 15 extends so as to overlap with the longitudinal direction of the output electrode 21, and one surface of the metal conductor as a wire is connected to the output electrode 21. Thus, by connecting the electric wire 15 at the connection portion extending in the longitudinal direction, a substantial conductor cross-sectional area can be increased in the electrode longitudinal direction as compared with the case where only one end is connected to the output electrode 21. Moreover, since the connection area of an electrode and the electric wire 15 can also be enlarged, the electrical resistance at the time of taking out an output can be reduced. For example, even when the metal film of the output electrode 21 is very thin such as 1 micron or less, the metal conductor is connected in the longitudinal direction such as 0.08 to 0.2 mm, so that the electrical resistance in the longitudinal direction is greatly increased. Can be reduced.

  The bent region 15t is a region that is provided at one end of the bus bar region 15a and in which the electric wire 15 is folded so that the extending direction thereof is changed. It includes a portion that is folded back and overlaps the electric wire 15. In the first embodiment, the bent region 15 t is near the end of the output electrode 21 and near the corner of the substrate 1.

  The lead regions 15b and 15c are regions that go out of the protective member 27 from the bent region 15t. The lead region has an internal lead region 15 b sandwiched between the substrate 1 and the protective member 27 and an external lead region 15 c that protrudes outside the protective member 27. The external lead region 15 c goes outside through the opening 29 of the protection member 27. The internal lead region 15 b is a region that faces the back side of the thin-film solar cell 10. Instead of the portion of the external lead region 15c that goes out from the protective member 27, another metal member or the like may be interposed. Since the terminal box 31 is located near the back center of the module as shown in the figure, the bus bar region 15a and the internal lead region 15b are bent at an acute angle in the bent region 15t.

  The thickness of the metal conductor that is the wire of the electric wire 15 is 0.08 to 0.2 mm, and the width is 2 to 4 mm. The metal conductor is processed into a flat shape by a method such as rolling an element wire. Examples of the material for the metal conductor include a flat rectangular copper wire, a thin aluminum wire, and a copper clad aluminum wire. An alloy wire having excellent bending resistance such as a copper nickel alloy, or a metal conductor plated with tin or the like may be used. The metal conductor may be embossed and the surface may be uneven. The insulating film is made of polyurethane, polyester, etc., and the thickness from the metal conductor surface is, for example, 0.005 to 0.04 mm. If an electromagnet wire generally called an enameled wire is used, it is easy to obtain and low cost can be achieved. Such enameled wires include polyurethane wire (UEW) that can be soldered without removing the coating at the same time as soldering, polyvinyl formal wire (PVF), polyurethane nylon with high mechanical strength of the coating Wire (UEWN), polyester wire (PEW) with excellent heat resistance, polyesterimide wire (EIW) with excellent heat resistance, polyamideimide wire (AIW) with high heat resistance and mechanical strength of the coating, polyimide with extremely good heat resistance There is a line (PIW). The coating film may be a multilayer made of a plurality of materials.

  These electric wires are formed by baking at a temperature of, for example, 100 to 500 ° C. after applying an insulating paint on the surface of the metal conductor. The coating is a relatively hard electrically insulating film having a pencil hardness of 4H to 6H, and has good adhesion strength to the metal conductor. When the adhesive layer 25 of the thermoplastic resin is used to attach the protective member 27, for example, when the adhesive layer 25 is thermocompression bonded at a temperature of about 150 ° C. using EVA as the EVA, the coating of the electric wire is the thermocompression bonding temperature from the viewpoint of heat resistance. It is desirable to have been baked at a higher temperature. Since the coating is thinner than the thin metal conductor, it is easy to bend, and even when bent, the coating hardly peels off. It is desirable that the metal conductor is a material that substantially keeps bending deformation when bent. In addition, since a polyurethane wire or the like is liable to be cracked for a long time if bending stress remains in the coating, the occurrence of cracking can be prevented by performing a heat treatment at a glass transition temperature or higher, for example, about 150 ° C. after bending. This heat treatment may use heat at the time of attaching the adhesive layer 25. Basically, it is desirable that the material of the adhesive layer 25 and the material of the coating are different materials and a combination of materials in which the material of the coating and the material of the adhesive layer 25 are not easily affected by each other. For example, when AIW or PIW which is excellent in stability against an organic solvent or the like is used, the reactivity with the adhesive layer 25 made of an organic material is low. The heat resistance of the coating is determined by the glass transition temperature and softening temperature of the material. When used outdoors at a high temperature for a long time, UEW or PEW having a heat resistant temperature of 110 ° C. or higher is excellent, and EIW having a heat resistant temperature of 150 ° C. or higher, AIW or PIW having a heat resistant temperature of 200 ° C. or higher is further excellent.

  The dielectric breakdown voltage of these coatings is approximately 200 to 300 V per micron thickness in proportion to the thickness. Therefore, a 0.005 mm film has a breakdown voltage of 1 KV or more. Although the voltage generated in the thin film solar cell module depends on the number of serial connection stages of the thin film solar cells 10, it is generally about 200 V or less and may have a dielectric breakdown voltage of about 1 KV. However, in consideration of long-term reliability, the dielectric breakdown voltage of the film is preferably 5 KV or more, and the thickness of the film is preferably 0.025 mm or more.

  The insulating coating of the electric wire 15 covers the metal conductor other than the portion that is electrically connected to the output electrode 21. In the internal bus bar region 15b, the wire 15 has a coating on the connection surface, which is one surface connected to the output electrode 21, removed to form an electrical connection portion. On the other hand, the film is attached to the non-connection surface, which is the other surface on the opposite side. The non-connecting surface to which this film is attached is reversed by the bent region 15t and faces the thin-film solar cell 10. Therefore, in the internal lead region 15b, the side of the electric wire 15 facing the thin film solar cell 10 is in a state where an insulating film is attached.

  The electrical connection between the bus bar region 15a of the electric wire 15 and the output electrode 21 is performed through the conductive adhesive 13 attached to the output electrode 21 in the first embodiment. The conductive adhesive 13 is a metal paste or a solder material. When using solder for connection, a soldering iron may be pressed from the non-connection surface B side to melt and connect the solder on the opposite connection surface A side. In that case, if it is partial, the coating on the non-connecting surface B side may be peeled off.

  Next, the manufacturing procedure of the thin film solar cell module according to Embodiment 1 will be described. FIGS. 4A to 4E and FIGS. 5F to 5G are top views for explaining the assembly process of the thin-film solar cell module according to the first embodiment.

  First, as shown in FIG. 4A, a coated wire 15 having an appropriate length longer than the output electrode 21 is prepared. The figure is a view of the ribbon-shaped electric wire 15 as viewed from the connection surface A side with the output electrode 21. Next, as shown in FIG. 4B, the coating in the region used for electrical connection of the bus bar region 15a on the connection surface A of the electric wire 15 is removed. As shown in the figure, in order to partially remove the film, it is preferable to use a method of mechanical removal using a file or the like. The surface of the metal member may be partially cut away. Next, as shown in FIG. 4C, a conductive adhesive 13 such as a metal paste is applied on the output electrode 21 of the prepared substrate with cell 100. The application position is a position corresponding to the area where the coating of the electric wire 15 is removed. Next, as shown in FIG. 4D, the connection surface A of the electric wire 15 is opposed to the output electrode 21, and the position where the conductive adhesive 13 is applied and the region where the film is removed are overlapped to output the electric wire 15 and the output. The electrode 21 is electrically connected and mechanically bonded. The coating covers almost the entire surface of the non-connection surface B that is opposite to the connection surface A of the electric wire 15. After bonding, the lead regions 15b and 15c protrude from one end of the substrate 1. These protruding portions are folded back at a position V1 near one end of the output electrode 21 to form a bent region 15t as shown in FIG. The bent region 15t is formed on the output electrode 21 in a region where the conductive adhesive 13 is not present. Since the position where the electric wire 15 is taken out from the protective member 27 is near the center of the substrate 1, the folding direction is set to be approximately the center of the substrate 1. Therefore, the bus bar area 15a and the lead areas 15b and 15c form an acute angle. The non-connection surface B faces the thin-film solar battery cell 10 by folding back. Although the electric wire 15 crawls on the thin film solar cell 10, the non-connecting surface B of the internal lead region 15 b covers the entire surface, so that the electric wire 15 and the thin film solar cell 10 can be connected without sandwiching an insulating sheet or the like. Is kept electrically insulative.

  Next, as shown in FIG. 5F, a protective member 27 is attached so as to cover the thin film solar cells 10 and the output electrodes 21 on the back side of the substrate 1. In the attaching step, first, a thermoplastic resin sheet such as EVA to be the adhesive layer 25 and a PET film as the protective member 27 are sequentially stacked on the substrate 1, and one end of the electric wire 15 is opened near the center of the substrate. It is assumed that it is in a state of being exposed to the outside through the opening 29 of 27. Next, EVA is thermocompression-bonded using a laminator or the like. Then, the terminal box 31 is attached so that the opening part 29 of the protection member 27 may be enclosed like FIG.5 (g). Positive and negative external electric wires 35 are drawn into the terminal box 31 and are electrically connected to the positive and negative electric wires 15. The external electric wire 35 and the electric wire 15 may be directly connected. However, since the electric wire 15 is relatively thin, a structure that prevents breakage or the like due to the force from the external electric wire 35 being directly applied to the electric wire 15 is preferable. For example, the figure shows a case where a terminal fitting 33 which is a metal member made of copper or copper alloy is fixed in the terminal box 31 and the external electric wire 35 and the electric wire 15 are respectively connected to the terminal fitting 33 by soldering 34. . Since the terminal fitting 33 is interposed, no force is directly applied to the electric wire 15 even when the external electric wire 35 is pulled from the outside. Further, it is desirable that the electric wire 15 has an appropriately loosened portion in the terminal box 31. Instead of the external lead region 15 c of the electric wire 15, a thick metal member may be used and pulled out to the outside of the protective member 27. In addition, when performing the connection by soldering, if the electric wire 15 is a polyurethane wire (UEW) or the like, soldering can be performed without removing the coating in advance, so that workability is excellent. After the terminal box 31 is filled with a sealing resin such as a silicone resin, a cover is attached to prevent water from entering. A thin film solar cell module is completed through the above steps.

  As shown in the figure, the two positive and negative electric wires 15 are provided with a bent region 15t on the same side of the substrate 1 and bent so that their tips intersect near the center of the substrate. As the diagonal position, the tips of the two positive and negative electric wires 15 may be antiparallel. Further, the position where the electric wire 15 is taken out from the protective member 27 may be biased to any side or corner instead of the center of the substrate. The positive and negative terminal boxes 31 may be separated, but from the viewpoint of reducing the number of members and reducing the cost, the positive and negative internal and external electric wire connections per module may be integrated into one terminal box 31. desirable.

  Moreover, the manufacturing process of said module is an example, and various procedure changes are possible. For example, the conductive adhesive 13 may be applied in advance to the region where the coating of the electric wire 15 is removed, and then the conductive adhesive 13 application portion of the electric wire 15 may be opposed to the output electrode 21 and connected. According to this procedure, it is easy to superimpose the position of the conductive adhesive 13 and the region from which the film has been removed. In addition, the electric wire 15 may be connected to the output electrode 21 after forming the bent region 15t in advance. In that case, the bent region 15 t may be fixed to the output electrode 21 with the conductive adhesive 13.

  Various patterns are also possible for the coating removal region of the bus bar region 15a. FIG. 6A is a top view showing an electric wire of the thin-film solar cell module according to Embodiment 1, and FIGS. 6B to 6F are top views showing modifications thereof. All are views as seen from the connection surface A side, and the non-connection surface B which is the back side of the paper surface is basically covered with a coating. In the first embodiment, since the conductive adhesive 13 scattered in the longitudinal direction is connected to the output electrode 21, the film is removed only around the corresponding part to form the removal region 15p. A film remains between the plurality of removed regions 15p, and this portion becomes a portion not connected to the output electrode 21. The non-connection portion has an effect of relaxing the stress generated between the electric wire 15 and the substrate 1 due to the temperature change. In addition, since the coating is adhered to the surface facing the output electrode 21 in this non-connected portion, the non-connected metal conductor and the output electrode 21 do not slide, and conductive dust that tends to cause a short circuit is generated. Hard to occur. Even when solder is used as the conductive adhesive 13, the solder is hardly exposed in the adhesive layer 25. Therefore, as compared with the conventional technique in which the wire is solder-plated on the surface, a short circuit due to tin whisker or the like is caused. Problems are less likely to occur. The removal region 15p is formed so as to leave a film on the side portion in the width direction of the electric wire 15 and in the vicinity thereof. The connecting surface A and the non-connecting surface B are continuously sandwiched near the side portion of the electric wire 15, so that it is difficult to separate from the metal conductor. Furthermore, since the whole side part of the electric wire 15 is covered with the film, it can prevent short-circuiting with the thin film photovoltaic cell 10 adjacent to the side part side.

  FIG. 6B is a modification of FIG. 6A, and has a structure in which the removal region 15 p is extended to the side portion in the width direction of the electric wire 15. Manufacturing is easier than the shape of (a), and it is effective when the width of the output electrode 21 is larger than the width of the electric wire 15. FIG. 6C shows a structure in which the removal region 15p is continuously formed in the longitudinal direction. Since the coating in the vicinity of the side portion is left, the coating is difficult to peel off, and a short circuit with the adjacent thin film solar cell 10 can be prevented. Since the removal can be performed continuously in the longitudinal direction, the removal process is easy. FIG. 6D shows a shape in which the film is further removed to the side of (c) and the film on the connection surface A side of the bus bar region 15a is almost completely removed, compared with (a) to (c). Processing is very easy. In addition, when the continuous removal area | region 15p like (c) and (d) is formed, the connection with the output electrode 21 may be performed intermittently in the longitudinal direction, or may be performed continuously.

  FIG. 6E shows a case where the removal region 15p is the same as (c), but the removal region 15p is linear when the electric wire 15 is meandering. The electric wire 15 covered with the film may meander when it is formed by rolling, but by forming the removal region 15p as a connection region linearly as shown in the figure, the linear output electrode 21 is formed. On the other hand, a good connection is possible, and a short-circuit can be prevented if the portion protruding by meandering is covered with a film.

  Further, it is preferable that the coating covers the electric wire 15 as much as possible except for the electrical connection portion. However, as shown in FIG. 6E, the removal region 15p may be formed up to the lead regions 15b and 15c. Absent. For example, as shown in FIG. 6F, the removal region 15p may be formed over the entire length of the electric wire 15 on the connection surface A side. It is only necessary that the non-connecting surface B side, which is the thin-film solar cell 10 side, is covered with the coating in the internal lead region 15b. Since the removal region 15p is formed continuously over the entire length, the processing of the electric wire 15 is facilitated. Further, the removal region 15p of the external lead region 15c can be used for electrical connection with an external electric wire.

  As shown in FIG. 6, as a method of locally removing the coating on one surface (connection surface A), for example, a method of mechanically removing a rotating grindstone, a rotating file, a rotating blade, a rotating brush, or the like is relatively used. Simple. While feeding the ribbon-shaped electric wire 15 at a constant speed in the longitudinal direction, a rotating file or the like is pressed against one surface to peel and remove the coating. By using a rotating file or a blade whose width is smaller than the ribbon-like width, it is possible to locally remove the film while leaving the film on the ribbon-like side portion. Moreover, the intermittent removal area | region 15p can be formed in a longitudinal direction by pressing a rotary file etc. intermittently. If the coating can be removed together with soldering, it is not always necessary to form the removal region 15p in advance.

  FIG. 7 is a cross-sectional view showing an electric wire of the thin-film solar cell module according to Embodiment 1, and is a cross-sectional view perpendicular to the longitudinal direction of the output electrode 21. FIG. 7A is a cross section of a portion where the entire circumference of the metal conductor 15m is covered with an insulating film 15f, and shows a cross section of a non-electrical connection portion before the film 15f is removed or in the internal lead region 15b. FIGS. 7B and 7C are cross sections of the electrical connection portion, where the coating 15f on the connection surface A is removed to form a removal region 15p. FIG. 7B corresponds to the cross section of the electric wire of FIG. 6A of the first embodiment or FIG. 6C of the modified example, and FIG. 7C shows the modified example of FIG. It corresponds to the cross section of (d). In either case, the coating 15f on the non-connection surface B side is not removed.

  FIG. 7D is a cross section of a portion where the electric wire 15 is connected to the output electrode 21 with the conductive adhesive 13, and FIG. 7E is a modification thereof. In the first embodiment, as shown in FIG. 7D, the metal conductor 15m of the electric wire 15 and the surface of the output electrode 21 are flat, and the coating 15f remains on both sides of the removal region 15p of the connection surface A. The thickness of the conductive adhesive 13 is set to be equal to or greater than the thickness of the film 15f. In addition, although a part of removal area | region 15p is not covered with the conductive adhesive 13 in the figure, the whole surface may be covered. Since the coating 15f is attached to the side portion of the electric wire 15, the distance between the output electrode 21 and the electric wire 15 on the side portion side from the connection portion is narrowed, and the conductive adhesive 13 is formed on the side portion of the electric wire 15. Can be prevented from protruding outside.

  Although the width of the electric wire 15 is narrower than the width of the output electrode 21 in FIG. 7D of the first embodiment, the width of the electric wire 15 is wider than the width of the output electrode 21 as shown in FIG. May be. In this case, the side portion of the electric wire 15 covered with the coating 15 f is located on the thin film solar cell 10 adjacent to the output electrode 21. Even if the second electrode 6 of the thin-film solar cell 10 is located at a position adjacent to the output electrode 21, the coating is attached to the connection surface A side facing the thin-film solar cell 10 in the protruding portion, so that it is electrically Insulation is maintained. Such a structure is particularly effective in narrowing the width of the output electrode 21 to increase the effective area for photoelectric conversion and increasing the cross-sectional area of the electric wire 15 to reduce output resistance loss. For example, the width of the removal region 15p may be made narrower than the width of the output electrode 21 so that the removal region 15p overlaps the region of the output electrode 21.

  FIG. 8A is a top view for explaining the structure around the electric wire bending region 15t of the thin film solar cell module according to Embodiment 1, and FIG. 8B is a top view showing the structure of a modified example. In the first embodiment, since the removal region 15p is formed only in the bus bar region 15a, not only the thin-film solar battery 10 side of the internal lead region 15b but also the opposite side is covered with the entire film. For this reason, the metal conductor 15m, which is a wire, is not exposed in the adhesive layer 25, and there is no problem that the metal conductor 15m and the adhesive layer 25 are in contact with each other at the exposed interface for long-term deterioration. According to the structure of FIG. 8B, when the adhesive layer 25 is a material that decomposes and generates an acidic substance, the metal conductor 15m can be prevented from being gradually corroded and bonded to the metal ions of the metal conductor 15m. Even in the case of a combination of materials that react with the layer 25, these reactions can be prevented. On the other hand, in the modified example of FIG. 8B, the removal region 15p of the electric wire 15 is continuously formed up to the internal lead region 15b as shown in FIG. 6E. Even in this case, since the coating is attached to the thin film solar cell 10 side, a short circuit with the cell can be prevented. Since the length of the removal region 15p is slightly larger than the length of the output electrode 21, the overlay accuracy of the removal region 15p in the longitudinal direction and the conductive adhesive 13 may be low, and the manufacturing is simplified. Further, since the coating is also attached to the side portion of the electric wire 15 as shown in the figure, it is possible to achieve highly reliable insulation in the long term.

  As described above, in the thin film solar cell module according to the first embodiment, the electric wire 15 extends in one direction in the same manner as the output electrode 21, and the connection surface A of the metal conductor 15m is opposed to the output electrode 21 and connected. Thin-film solar cell module having a bus bar region 15a, a bent region 15t folded back so as to change a direction extending with respect to the bus bar region 15a, and an internal lead region 15b led out of the protective member 27 from the bent region 15t It is. The wire 15 includes a ribbon-like metal conductor 15m longer than the output electrode 21 as a thin metal wire, and a coating 15f thinner than the metal conductor 15m formed by baking an insulating paint on the surface of the metal conductor 15m. , A covered electric wire. Then, in the bus bar region 15a, the coating 15f adheres to the non-connection surface B opposite to the output electrode 21 of the metal conductor 15m, and the electric wire 15 is folded back in the bending region 15t. B is covered with a film 15f in the internal lead region 15b.

  In addition, as a manufacturing method thereof, a step of preparing the substrate with cell 100, a ribbon-like metal conductor 15m longer than the output electrode 21 as the electric wire 15, and a thickness of the metal conductor formed by baking an insulating coating on the surface of the metal conductor 15m. A step of preparing a covered electric wire having a thinner coating 15f, a step of forming a bus bar region 15a, a bent region 15t, and an internal lead region 15b in the electric wire 15 and connecting the bus bar region 15a to the output electrode 21 And a step of attaching a protective member 27 that covers the thin-film solar battery cell 10 and the output electrode 21 to the substrate 100 with a cell. And the connecting step is a step of removing the coating 15f on the surface on the output electrode 21 side in a state where the coating 15f is attached to the non-connecting surface B of the metal conductor 15m on the opposite side to the output electrode 21 in the bus bar region 15a, The step of turning back the non-connecting surface B to which the coating film 15f is attached in the bent region 15t so as to face the thin-film solar battery cell 10, and the non-connecting surface B covered with the coating film in the internal lead region 15b. And a step of disposing it so as to face each other.

  By using a ribbon-shaped electric wire 15 that is longer than the output electrode 21 and forming a bent region 15t that is folded back so that the extending direction changes, the bus bar region 15a and the lead region 15b are formed of one electric wire material. Realized. Therefore, there is no connection point to which different members are connected in the middle, and the problem of lowering the power generation characteristics due to deterioration of the connection point does not occur in long-term use. Since the coating is attached to the non-connecting surface B side in the bus bar region 15a, the insulating property is excellent and the reaction with the adhesive layer can be suppressed. Furthermore, in the bus bar region 15a, since the insulating coating 15f adheres in a region other than the region connected to the output electrode 21, a short circuit with the adjacent thin film solar cell 10 is unlikely to occur. Further, since the electric wire 15 having the coating 15f thinner than the thickness of the metal conductor 15m formed by baking the insulating paint is used, it is easy to bend back so that the coating 15f is hardly peeled even when folded. Since it can be easily electrically insulated from the thin film solar cell 10 in the internal lead region 15b by folding it back, the manufacturing process is simplified. In addition, since the folding region 15t can be made thin, the space between the protective member 27 and the substrate 1 can be made relatively narrow, and the amount of the adhesive layer 25 used can be reduced. Arrangement of different electric wire members and a process of connecting them can be omitted. Further, since there are few portions where the adhesive layer 25 and the metal conductor are in direct contact with each other, a reaction between the material of the adhesive layer 25 and the metal conductor can be prevented, and a highly reliable module can be realized in the long term.

<Embodiment 2. >
FIG. 9 is a perspective view showing an exploded structure of the thin film solar cell module according to the second embodiment. FIG. 10 is a perspective view and a partial cross-sectional view of the thin film solar cell module according to the second embodiment in which the structure of FIG. FIG. 10A is a completed view in which the components shown in FIG. 9 are assembled, and FIG. 10B is a cross-sectional view perpendicular to the periphery of the substrate 1 around the wire 15 taken out.

  The thin film solar cell module according to the second embodiment is different from the first embodiment in the protective member, and uses the same material as the substrate 1 as the protective member 51. Typically, both the substrate 1 and the protection member 51 are made of a glass material. As in the first embodiment, the substrate 1 and the protection member 51 are bonded to each other with the adhesive layer 25. When both the protective member 51 and the substrate 1 are made of a glass material, the structure is excellent in impact resistance similar to that of laminated glass. The protective member 51 is preferably substantially the same as the substrate 1 and has a thermal expansion coefficient close to that of the substrate 1. This is because the protective member 51 is made of the same hard material as that of the substrate 1, and therefore, when the thermal expansion coefficient is different, the bonded module structure is likely to be deformed or damaged when a temperature change occurs. Since the protective member 51 side is not the sunlight incident side, the substrate 1 may have different optical characteristics, thickness, surface processing, and the like.

  Although it is possible to make a through hole in the protective member 51 made of glass or the like and take out the electric wire 15 to the outside, in the second embodiment, the substrate 1 and the protective member 51 are attached as shown in FIG. The electric wire 15 was taken out of the protective member 51 from the mating side surface. Easy to manufacture without the need for drilling. In addition, although the figure showed the case where it came out from the adhesive layer side surface 25s, you may make it come out of sealing materials other than the adhesive layer 25, etc. The electric wires 15 that are exposed to the outside from the bonded side surfaces may be further covered with another resin or the like.

  As shown in FIG. 9 and FIG. 10A, the two positive and negative electric wires 15 are bent so as to approach each other inside the bonded portion, and come out so as to be generally perpendicular to the peripheral edge of the substrate 1. did. In order to take out the electric wire 15 in this way, a plurality of bent portions are formed on at least one of the positive and negative electric wires 15 inside the substrate 1 and the protective member 51 bonded together. In addition to the bent region 15t above the output electrode 21, a second bent region 15w is formed in the internal lead region 15b. The figure shows a case where two bent portions are formed in each of the positive and negative electric wires 15. Three or more bent regions of each electric wire 15 may be formed. Further, one electric wire may be taken out from the side as it is without forming a bent region, and the other electric wire may be bent inside so as to approach the electric wire side.

  The external lead region 15 c of the electric wire 15 taken out from the bonded side surface is bent to the back side along the side surface of the protection member 51. Although not shown in the drawing, the bent electric wire 15 and the protective member 51 may be bonded with an adhesive or the like. An adhesive or a sealing material may be applied to the side surface from which the electric wire 15 is taken out, and the electric wire 15 taken out by these may be bonded or protected.

  The electric wire 15 bent to the back side is led into a terminal box 31 fixed to the back side of the protection member 51. In the second embodiment, since the two positive and negative electric wires 15 come close to the outside from the vicinity of the center of one side of the rectangular substrate 1, the terminal box 31 is installed immediately on the back side of the outlet. Further, a protective cover is attached to the side surface that is the outlet of the electric wire 15 to protect the electric wire 15. Further, as shown in the figure, one surface of the terminal box 31 was extended so as to cover the side surface of the substrate 1 to form a protective cover portion 31b. The protective cover portion 31b is connected to the terminal box main body 31a, and the electric wire 15 is led into the terminal box main body 31a connected to the external electric wire 35 without being exposed to the outside, and is connected to the external electric wire 35. FIG. 10B shows a structure in which a groove is formed in the conducting wire of the external electric wire 35 and the tip of the metal conductor 15m of the electric wire 15 is inserted and connected to the groove. The electric wire 15 has a structure in which it is loosened in the terminal box 31 and is not easily broken by an external stress. The connection structure in the terminal box 31 is not limited to such a structure, and various changes can be made.

  Next, the manufacturing process of this module will be described. 11 (a) to 11 (e), 12 (f) to 12 (g), and 13 (h) are partial top views for explaining the assembly process of the thin film solar cell module according to the second embodiment. In FIG. 11, a ribbon-shaped electric wire 15 with a coating is prepared (FIG. 11 (a)), and a coating removal region is formed on the connection surface A of the bus bar region 15a (FIG. 11 (b)). The conductive adhesive 13 is applied on the 100 output electrodes 21 (FIG. 11C), and the bus bar region 15a of the electric wire 15 and the output electrode 21 are connected and fixed via the conductive adhesive 13 (FIG. 11). The point (d) is the same as in the first embodiment.

  Next, the electric wire 15 is folded back at a location V4 near one end of the output electrode 21 to form a bent region 15t (FIG. 11E), but the electric wire 15 follows the periphery of the substrate 1 when bent. In the second embodiment, as shown in the figure, the substrate 1 is rectangular and the output electrode 21 is formed along one side thereof. Therefore, the internal lead region 15b is bent by being bent almost vertically in the bent region 15t. Then, it crawls along another side of the substrate 1.

  Next, as shown in FIG. 12 (f), the second lead region 15 w is formed by bending again at an appropriate portion V 5 of the internal lead region 15 b, and the external lead region 15 c of the electric wire 15 is approximately relative to the peripheral portion of the substrate 1. It came out vertically. In this state, a protective member 51 is further overlapped and bonded to the substrate 1 (FIG. 12G). In addition, since the electric wire 15 is similarly connected also to the other output electrode 21, it becomes a structure where two positive and negative electric wires adjoin each other and come out from the bonding side surface.

  Next, as shown in FIG. 13H, the external lead region 15 c is bent to the back side, and the terminal box 31 is attached to the back side of the protection member 51. Inside the terminal box 31, the external electric wire 35 and the electric wire 15 are connected by the solder connection 34 etc., and the terminal box 31 is sealed. When viewed from the back side as shown in FIG. 13, a part of the terminal box 31 protrudes from the side surface, and the outlet of the electric wire 15 is covered by the protruding part.

  In the second embodiment, since a plurality of turns are performed on the electric wire 15, it is desirable that the coating is attached not only to the non-connection surface B but also to the connection surface A in the internal lead region 15 a. Further, it is desirable that a film is adhered to the entire surface of the external lead region 15c.

  As described above, when the same material as the substrate 1 is used as the protective member 51, the thin film solar cell 10 and the internal electric wire are excellent in mechanical protection and environmental resistance, but conventionally, the wire extraction structure is complicated, There were many cases where the number of members increased and the processing became difficult. In the second embodiment, an electric wire 15 having a ribbon-like metal conductor longer than the output electrode 21 and an insulating coating thinner than the thickness of the metal conductor formed by baking an insulating paint on the surface of the metal conductor is used as the wire. Therefore, the take-out position can be freely adjusted while maintaining electrical insulation from the thin-film solar battery 10. Further, the bonding interval between the protective member 51 and the substrate 1 can be narrowed, and the amount of the adhesive layer 25 can be reduced. Furthermore, since either one of the positive and negative electric wires 15 is provided with a plurality of bent regions so that the electric wires are close to each other, it is structured to be taken out from the bonded side surface and guided into the terminal box 31 installed on the back side. One terminal box 31 is sufficient, and the members to be used can be greatly reduced. Furthermore, since the one surface of the terminal box 31 is extended to the side surface of the board | substrate 1 and the electric wire 15 was guide | induced in the terminal box main body 31a connected with the external electric wire 35, without exposing outside, the electric wire 15 is connected. A module that is protected from the mechanical and external environment and has long-term reliability can be realized.

<Embodiment 3. >
The thin film solar cell module of the third embodiment is the same as that of the first and second embodiments, but is characterized in that the bent region 15t is reinforced. FIG. 14 is a partial top view and a cross-sectional view of the periphery of the bending region 15t of the thin film solar cell module according to the third embodiment. FIG. 14B is a cross-sectional view taken along the dotted line X1-X2 in FIG. The film removal region 15p on the connection surface A side of the electric wire 15 is also formed in the bent region 15t. A thin conductive member 61 such as a metal foil is affixed to the removal region 15p on the outside of the folded connection surface A. Since the conductive member 61 electrically connected across the folded conductor members is attached, mechanical and electrical reinforcement of the folded portion is performed. Thereby, generation | occurrence | production of the crack of a metal conductor in the bending area | region 15t and an electrical resistance increase are suppressed, and a long-term reliable module is realizable. From the viewpoint of mechanical reinforcement, the conductive member 61 is preferably a metal foil, but from the viewpoint of electrical reinforcement, a conductive paint may be used. These conductive members 61 may be affixed in advance at positions where they are folded back, or may be formed after the folding region 15t is formed. Since the thickness of the electric wire 15 is increased by attaching the conductive member 61, the conductive member 61 is preferably a material thinner than the metal conductor of the electric wire 15. It should be noted that the attached conductive member 61 should not protrude from the adjacent thin film solar cell 10 side.

  FIG. 15 is a partial top view and a cross-sectional view of the vicinity of a bending region 15t of a modification of the thin film solar cell module according to the third embodiment. FIG. 15B is a cross-sectional view taken along the dotted line X3-X4 in FIG. A region where the film is removed is provided on the non-connection surface B of the bent region 15t, and the conductive member 62 is sandwiched between the folded conductor members. The conductive member 62 is a metal foil or a conductive adhesive. The conductive member 62 mechanically and electrically reinforces the folded portion. The conductive member 62 is installed and sandwiched before the bent region 15t is formed. Since the conductive member 62 is structured to be wrapped by the electric wires 15, the conductive member 62 is unlikely to deteriorate.

  The wire 15 may be a polyurethane wire, and the conductive adhesive that sandwiches the wire 15 may be solder. In a state where the solder material is sandwiched in the folding region 15t, the soldering iron is pressed from the outside and heated. Thereby, even if it does not remove a film beforehand, a film can be removed at the time of solder melting, a solder can connect between metal conductors, and manufacture is very simple.

  FIG. 16 is a partial top view and a cross-sectional view of the vicinity of a bending region 15t of a modification of the thin film solar cell module according to the third embodiment. FIG. 16B is a cross-sectional view when the dotted line X5-X6 in FIG. The bent region 15t has a structure in which a region where the film is removed is provided near the side portion of the folded electric wire 15 and a conductive member 63 such as a metal foil is attached to the region. After forming the bent region 15t, the coating of the part of the side portion of the folded electric wire 15 on the connection surface A side and the portion of the vicinity of the non-connection surface B side of the electric wire 15 before folding is removed with a file or the like. Thereafter, the conductive member 63 is attached to the metal conductor. In this way, the structure is easy to manufacture after forming the bent region 15t. Since the coating removal region 15p is on the output electrode 21 region as shown in the figure, short-circuiting with the thin-film solar cell 10 is unlikely to occur.

  Further, as a method of mechanically reinforcing the bent region 15t, a self-bonding material may be used for the coating of the electric wire 15. For example, when the surface of the coating is a fusion layer made of polyamide or the like, the non-connection surfaces B facing each other in the bent region 15t can be heat-sealed. The heat for attaching the protective member 27 may be used for the heat of fusion, or the fusion treatment may be performed before the attachment. Since the folded structure is fixed by the coating, the mechanical strength is increased and the module becomes highly reliable in the long term. When a material having a softening temperature higher than that of the material of the adhesive layer 25 is used as the fusion layer, the reinforcing effect is further increased.

  Even if the above-described reinforcing structure of the bent region 15t is applied to the second bent region 15w, the same effect can be obtained.

<Embodiment 4. >
The basic structure of the thin film solar cell module of the fourth embodiment is the same as that of the second embodiment, but a structure in which a spacer is sandwiched between the protective member 51 and the substrate 1. FIG. 17 is a partial top view and a cross-sectional view of the thin film solar cell module according to the fourth embodiment. FIG. 17A is a partial top view of the substrate 1 in a state before the protective member 51 is pasted, as viewed from the back side, and FIG. 17B is a substrate thickness direction along the dotted line X7-X8 in FIG. It is sectional drawing at the time of cut | disconnecting in FIG.

  As shown in the drawing, a plurality of thin plate-like spacers 71 are sandwiched between the substrate 1 and the protective member 51 as viewed from above. The spacer 71 is a thickest structure sandwiched between the protective member 51 and the substrate 1. The spacer 71 protects the inside from damage due to stress by keeping the distance when the protective member 51 and the substrate 1 are bonded by the adhesive layer 25 substantially constant in the plane and dispersing the bonding stress. is there. The shape of the spacer 71 may be, for example, a square or a circle having a side or a diameter of about 3 to 10 mm when viewed from the top. An elongated shape along the periphery of the substrate 1 may be used. The thickness of the spacer 71 is at least twice that of the electric wire 15. For example, if the thickness of the coated electric wire 15 is 0.15 mm, for example, the thickness is preferably at least 0.3 mm or more, and is preferably about 3 times 0.45 mm. Further, the thickness is desirably equal to or greater than the thickness of the bent region 15t. When the conductive member is attached as in the third embodiment, the thickness may be set in consideration of the thickness. Thereby, even if the protection member 51 and the board | substrate 1 are bonded together, the bending area | region 15t is not pressurized directly by these. Since the structure is such that pressure is not applied concentrated on the bending region 15t, deterioration due to stress in the bending region 15t is prevented, and a highly reliable module is obtained.

  The material of the spacer 71 is preferably an electrically insulating material and is harder than the material of the adhesive layer 25. Further, when the protective member 27 is thermocompression bonded using EVA as the adhesive layer 25, it is desirable that the material maintain an appropriate hardness and shape even if it is processed at the processing temperature during the thermocompression bonding. On the other hand, in order to prevent damage to the thin-film solar battery cell 10 or the like, those having appropriate softness and flexibility are preferable. For example, thermosetting resin-based elastomers such as urethane rubber, silicone rubber, and fluorine rubber, and thermoplastic elastomers whose softening temperature is equal to or higher than the processing temperature at the time of thermocompression bonding are suitable as the material of the spacer 71.

  The installation position of the spacer 71 is preferably arranged in the vicinity of the bent region 15t, avoiding the back side of the thin-film solar battery cell 10. For example, in FIG. 17, since the output electrode 21 is near the periphery of the substrate 1, the spacer 71 a is disposed between the bent region 15 t and the periphery of the substrate 1. Further, although not in the vicinity of the bent region 15t, the spacer 71a is provided near the corner of the rectangular substrate, so the spacer 71b is also disposed in the vicinity of the opposite corner. By disposing the plurality of spacers 71 at positions that are substantially symmetrical with respect to the center of the substrate 1, the distance between the protective member 51 and the substrate 1 can be made substantially uniform.

  Moreover, instead of the spacer 71 as described above, a plurality of folded wires 15 with a coating can be produced to form a spacer. There is no need to prepare a separate material for the spacer 71. Moreover, it is good also as a substitute of the spacer 71b by bending one end of the electric wire 15 on the opposite side to the bending area | region 15t in multiple times. Since one end of the electric wire 15 on the opposite side does not contribute to the electrical connection, the metal conductor may be broken during the bending process or due to the stress sandwiched between the substrate and the protective member, and the manufacture is easy. . For example, when the thickness of the spacer 71 is about three times the thickness of the electric wire 15, a portion of the electric wire 15 that is folded three times may be manufactured. Further, although the amount of use of the electric wire 15 increases, a long folded structure that folds in the longitudinal direction of the output electrode 21 may be formed in the bus bar region 15 a and used as the spacer 71. As the spacer 71 becomes longer, the concentration of stress is dispersed, and the connection between the output electrode 21 and the electric wire 15 can be strengthened by this stress.

  In addition, the spacer 71c may be installed in the vicinity of the second bent region 15w in the middle of the internal lead region 15b. As shown in the figure, when two positive and negative electric wires 15 come out from the side surfaces of the mating surfaces, for example, a spacer 71 c is installed between the two electric wires 15. In the figure, it partially covers the back surface of the thin-film solar battery cell 10, but it is preferable to install it in a region where there is no cell near the periphery of the substrate as much as possible. By the spacer 71c installed near the outlet of the electric wire 15, the distance between the protective member 51 and the substrate 1 at that portion becomes larger than the thickness of the electric wire 15, and the electric wire 15 is strongly sandwiched between the corners of the protective member 51 and the substrate 1. Can be prevented.

<Embodiment 5. >
The thin film solar cell module of the fifth embodiment uses a distribution 15 with a coating as in the first and second embodiments, but the removal area 15p of the coating in the bus bar area 15a is different. In the bus bar region 15a, the removal region 15p was formed on one side of the ribbon-shaped electric wire, and the other side was left covered with the coating. Moreover, the coating film was also removed from the connecting surface A side and the non-connecting surface B side following the one side. The coating remained attached to the other side, the connecting surface A side following the side, and the non-connecting surface B side.

  FIG. 18 is a top view for explaining the assembly process of the thin-film solar battery module according to the fifth embodiment. First, as shown in FIG. 18A, a thin coated wire 15 having an appropriate length longer than the output electrode 21 is prepared. The figure is a view of the ribbon-shaped electric wire 15 as viewed from the connection surface A side with the output electrode 21. Next, as shown in FIG. 18B, a part of the coating on one side of the electric wire 15, the subsequent connection surface A side, and the non-connection surface B side is removed. The coating remains attached to the other side, the connecting surface A side following the side, and the non-connecting surface B side. For example, such a removal region 15p can be formed by inserting one side of the electric wire 15 into two rotating grindstones that are close to the thickness of the metal conductor and moving in the longitudinal direction.

  Next, as shown in FIG. 18C, a conductive adhesive 13 such as a metal paste was applied to the removal region 15 p of the electric wire 15. Next, as shown in FIG. 18D, the connection surface A of the electric wire 15 is opposed to the output electrode 21, and the position where the conductive adhesive 13 is applied and the region where the film is removed are overlapped to output the electric wire 15 and the output. The electrode 21 was electrically connected and mechanically bonded. As shown in the figure, when the output electrode 21 is on one side of the substrate 1, the other side to which the coating of the electric wire 15 is attached is directed to the thin film solar cell 10, and the conductive adhesive 13 is applied. It is good to connect the side part side toward the outside of the substrate 1. The other side part to which the film adheres may protrude beyond the adjacent thin film solar cell 10.

  Next, the electric wire 15 is folded back at V6 near one end of the output electrode 21 to form a bent region 15t as shown in FIG. The removal region 15p may be formed up to the side of the bent region 15t, and the folded portions may be connected by the conductive adhesive 13 as in the third embodiment. Since the subsequent steps are the same as those in the first and second embodiments, a description thereof will be omitted.

  FIG. 19 is a partial cross-sectional view of the thin-film solar cell module according to the fifth embodiment, and is a cross-sectional view of a portion obtained by cutting a portion where the electric wire 15 is connected to the output electrode 21 perpendicularly to the longitudinal direction. As shown in the figure, it is connected to the output electrode 21 only on one side of the electric wire.

  In the above description, the conductive adhesive 13 is used for the connection between the output electrode 21 and the electric wire 15. However, the removal region 15p may be directly welded to the output electrode 21 using ultrasonic waves or the like. When welding is used, the material used can be reduced.

  As described above, in the fifth embodiment, in the bus bar region 15a, the removal region 15p is formed only on one side of the electric wire 15 and connected to the output electrode 21, so that the other side or the vicinity thereof is connected. Even if the insulating film adheres to the surface A and the width of the output electrode 21 is narrow or the cross-sectional area of the electric wire 15 is increased, the connection structure is excellent in electrical insulation with the adjacent thin-film solar cell 10. Can be realized. Further, since the coating is also attached to the non-connecting surface B side of the other side portion, the interface deterioration between the electric wire 15 and the adhesive layer 25 can be reduced. By forming the removal region 15p within the range of one side including any one side portion from the center of the ribbon-like width, the width of the output electrode 21 can be reduced to about half of the width of the electric wire 15. Further, when the removal region 15p is formed by removing the coating only on one side or in the immediate vicinity thereof, the width of the output electrode 21 can be made extremely narrow.

  The removal region 15p may be formed only in the vicinity of one side, and the other side may be covered with a coating, or the coating may remain on one side or the non-connection surface B side. Further, the coating on one side may be removed intermittently without being continuously removed.

  As described above, in the present invention, a wire with a coating is used as an electric wire, so that it has excellent long-term reliability and can be easily manufactured. Note that part of the structure described in any of the above embodiments may be combined with other embodiments unless there is a technical problem. Further, although one electric wire 15 is used for one output electrode 21, a plurality of electric wires 15 may be connected by being divided in the longitudinal direction. The bent region 15t may not be near one end of the output electrode 21. Further, a bent region 15t may be provided at both ends in the longitudinal direction with respect to one output electrode 21 so that the output can be output from both sides via the lead region. Whether the folding region 15t is a mountain fold or a valley fold may be appropriately selected from the convenience of the process and the shape of the removal region 15p.

  Further, in the above, a wire with a coating is used as the electric wire, but a structure in which a plurality of electric wires are folded inside as in the second embodiment, a cover structure for protecting the outside, or a wire as in the fourth embodiment is formed by bending. It is also possible to realize a structure such as a spacer using a ribbon-shaped electric wire without a coating. Even in that case, the effect of each structure can be obtained.

  The thin-film solar cell module and the manufacturing method thereof of the present invention can improve the reliability of the solar cell module during long-term use and simplify the manufacturing process.

DESCRIPTION OF SYMBOLS 1 Substrate, 2 1st electrode, 4 Photoelectric conversion layer, 6 2nd electrode, 10 Thin film photovoltaic cell, 13 Conductive adhesive, 15 Electric wire, 15a Bus bar area, 15b Internal lead area, 15c External lead area, 15t Bending area 15f coating, 15m metal conductor, 15p removal region, 15w second bending region, 19 groove, 21 output electrode, 25 adhesive layer, 25s adhesive layer side surface, 26 opening, 27 protective member, 29 opening, 31 terminal box, 31a terminal box body, 31b protective cover, 33 terminal fitting, 34 soldering, 35 external electric wire, 51 protective member, 61, 62, 63 conductive member, 71, 71a, 71b, 71c spacer 100 substrate with cell, A connection surface , B Non-connection surface, V1, V2, V4, V5, V6, V7 Folded part.

Claims (13)

A plurality of thin-film solar cells connected in series, and a substrate provided with an output electrode that is long in one direction at the end of the series connection; the plurality of thin-film solar cells attached to the substrate; and the output electrode A protective member that covers and an electric wire that guides electric power from the output electrode to the outside of the protective member,
A bus bar region in which the electric wire extends in the one direction and is connected to the output electrode, a bent region that is folded back so that a direction extending with respect to the bus bar region changes, and from the bent region to the outside of the protective member A thin film solar cell module having a lead region for guiding,
The electric wire is a thin coated electric wire having a wire made of a thin metal plate and a coating thinner than the thickness of the wire made by baking an insulating paint on the surface of the wire,
In the bus bar region, the coating on one surface of the electric wire is removed and the electric wire and the output electrode are electrically connected, and the other surface of the electric wire is in a state where the coating is attached,
The other surface of the wire to which the coating is attached is folded back in the bending region and faces the thin-film solar cell in the lead region ,
The thin-film solar cell module, wherein the coatings that are bent and opposed to each other are fused in the bent region. A substrate having a plurality of thin film solar cells connected in series and an output electrode that is long in one direction at an end of the series connection, and the plurality of thin film solar cells attached to the substrate and the output electrode A protective member that covers and an electric wire that guides electric power from the output electrode to the outside of the protective member,
A bus bar region in which the electric wire extends in the one direction and is connected to the output electrode, a bent region that is folded back so that a direction extending with respect to the bus bar region changes, and from the bent region to the outside of the protective member A thin film solar cell module having a lead region for guiding,
The electric wire is a thin coated electric wire having a wire made of a thin metal plate and a coating thinner than the thickness of the wire made by baking an insulating paint on the surface of the wire,
In the bus bar region, the coating on one surface of the electric wire is removed and the electric wire and the output electrode are electrically connected, and the other surface of the electric wire is in a state where the coating is attached,
The other surface of the wire to which the coating is attached is folded back in the bending region and faces the thin-film solar cell in the lead region,
A thin-film solar cell module comprising a conductive member that electrically connects the bent wires in the bent region. The thin film solar cell module according to claim 2,
The thin film solar cell module, wherein the conductive member is attached to the outside of the bent electric wire. The thin film solar cell module according to claim 2,
The thin film solar cell module, wherein the conductive member is sandwiched between the bent electric wires. The thin film solar cell module according to claim 1 or 2 ,
The film has a region to which the film adheres in addition to a region connected to the output electrode on the one surface in the bus bar region. The thin film solar cell module according to claim 5 ,
The region where the coating film adheres to the one surface includes the entire one side portion of the electric wire. The thin-film solar cell module according to claim 6 ,
The thin-film solar battery module, wherein the one side portion of the electric wire is positioned on an adjacent thin-film solar battery cell in the bus bar region. The thin film solar cell module according to any one of claims 5 to 7 ,
A region connected to the output electrode in the bus bar region is formed within a range including any one side portion from the center of the width of the electric wire. The thin film solar cell module according to any one of claims 5 to 7 ,
The thin film solar cell module, wherein the one surface of the electric wire has a region where the coating is removed continuously from the bus bar region, the bent region, and the lead region. The thin-film solar cell module according to any one of claims 1 to 9 ,
The electric wire connected to at least one of the positive and negative output electrodes is bent in the bending region so as to approach the electric wire connected to the other output electrode, and then further out from the periphery of the substrate in the lead region. The thin-film solar cell module is characterized in that it is folded back so that both electric wires come close to the outside from the bonding side surface of the substrate and the protective member. The thin-film solar cell module according to claim 10 ,
A terminal box installed on the back surface of the protective member, and a protective cover portion that covers a side surface of the protective member and the substrate on which the positive and negative electric wires come out,
The thin film solar cell module, wherein the protective cover portion is connected to the terminal box, and both the positive and negative electric wires are led into the terminal box through the protective cover portion. The thin film solar cell module according to any one of claims 1 to 11 ,
The thin film solar cell module, wherein the substrate and the protective member are made of a glass material, and a spacer thicker than twice the electric wire is sandwiched between the substrate and the protective member. The thin film solar cell module according to claim 12 ,
The thin film solar cell module, wherein the spacer is formed by folding back the electric wire with the coating.

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