JP3006711B2 - Solar cell module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solar cell module,
In particular, the present invention relates to an improvement in a solar cell serialization process.

[0002]

2. Description of the Related Art An amorphous silicon solar cell is shown in FIG.
As shown in FIG. 2, a conductive substrate 404, a photoelectric conversion layer 403 made of amorphous silicon, a transparent conductive layer 402 also serving as an anti-reflection layer, and a current collecting grid electrode 401 are formed in this order. Light incident from the grid electrode 401 side is converted into a current in the photoelectric conversion layer 403, and is extracted as an output between the current collecting grid electrode 401 and the conductive base 404 via the transparent conductive layer 402.
When the photoelectric conversion layer 403 is made of, for example, only one layer of amorphous silicon, its output voltage is as low as about 0.7 V. Therefore, in practice, several to hundreds of photoelectric conversion layers are connected in series. In addition, various output increasing techniques are employed. Specifically, in the case of a solar battery cell in which a photoelectric conversion layer is provided on a conductive substrate, it is necessary to produce a solar battery module in which cells are directly connected via a wiring member and cells are connected in series. Was.

Conventionally, a solar cell module has, for example, a bus bar 6 on each solar cell 600 as shown in FIG.
01 is connected to one end of a connection copper tab 603 via a solder 602a, and the other end of the copper tab 603 removes a semiconductor layer of a solar cell adjacent to the solar cell. Exposed portion 60 of conductive substrate formed by
4 via the solder 602b. In addition, since a part of the conductive base is exposed around the solar cell, in order to prevent a short circuit between the exposed portion and the bus bar 601, the vicinity of both ends of the bus bar 601 is insulated via an insulating material 605. In addition, an insulating material 606 is provided along one side of the solar cell 600 in order to prevent contact between the base of the solar cell and the adjacent solar cell.
The bus bar 601 is connected to a large number of current collecting electrodes 607 via a conductive adhesive 608 and is a member on which current is concentrated. Therefore, a metal wire having high conductivity is used. In the figure, reference numeral 609 denotes an electrode terminal tab, and 610 denotes a sealing resin.

FIG. 7 illustrates the conventional serialization process of the solar module in more detail. First, FIG.
As shown in (a), a part of the exposed portion of the conductive substrate formed around the solar battery cell 600 has a resin 60 as an insulating material.
5 and a resin 606 as an insulating material applied along one side edge, and these are cured. Next, as shown in FIG. 7B, the bus bar 601 is adhered to the current collecting electrode 607 via the conductive adhesive 608, and the adhesive is cured. next,
As shown in FIG. 7C, another solar cell is arranged adjacent to the solar cell, and one end of the serial metal tab 603 and one end of the bus bar 601 of the solar cell are soldered 602 a. Through the metal tab 603
Is connected to the exposed conductive substrate 604 of another adjacent solar cell via the solder 602b, thereby completing the serialization process.

FIG. 17 shows another example of the structure for forming the exposed portion of the conductive substrate.
01, a thin film semiconductor layer is formed, a substrate exposed portion 1702 is provided in a part of the substrate 1701, and a method of connecting the bus bar 1704 of the first solar cell and the substrate exposed portion 1702 of the second solar cell is proposed. ing. In FIG. 17, 1
703 is a current collecting electrode.

[0006] As another example, there is a method of superimposing on the light incident side of an adjacent solar cell.

[0007]

However, in the above-described conventional method of serializing the solar cell modules, it is necessary to provide an insulating material, fix the bus bar 601, and solder the wiring material for the serialization. Is too slow and productivity is poor. Further, since current concentrates on the bus bar 601, it is necessary to form the bus bar 601 with a conductor having a large cross-sectional area, which hinders the thinning of the solar cell. In this case, if the thickness of the bus bar 601 is reduced thinly, the width must be increased in order to increase the current capacity.
There is a problem that the output of the solar battery cell is reduced according to the so-called shadowed portion covered by 01. In addition, since the problem of current concentration also occurs in the serial connection metal tab 603 connected to the bus bar 601, it is necessary to increase the cross-sectional area of the metal tab 603. Furthermore, since the solders 602a and 602b are frequently used, there is a possibility that the residual flux required at the time of soldering may adversely affect the reliability of the cell.

[0008] Further, the above-mentioned conventional solar cell module includes:
After each solar cell is connected in series, it is necessary to coat it with a coating material such as a polymer resin such as EVA or a fluororesin in order to have environmental resistance. The amount of material to be coated on the battery cells is also increased, so that the cost of the solar cell module is increased, and the thickness and weight of the solar cell module are increased.

Further, when the thickness of the bus bar electrode is large,
Even if the amount of the coating material is increased, the entire coating material on the bus bar electrode is still thin, so that there is a problem that the scratch resistance of the solar cell module is poor.

In the case of the configuration shown in FIG. 17, since it is necessary to provide a substrate exposed portion 1702 in the substrate 1701 in order to perform serialization, the substrate exposed portion 1702 is a portion that does not contribute to power generation of the solar cell. That the effective area is small and the solar cell cannot be used effectively, that the bus bar 1704 needs to be provided, this part also becomes a shadow and conversion efficiency is lost.
There is a manufacturing problem that it is difficult to form a complex shape like the substrate 1701 or to form a complicated shape.

Further, there are problems that the electrical connection is unstable and that the connection is easily deteriorated when the solar cell is bent by applying an external force.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a solar cell module having a small number of work steps and a high productivity instead of a serialization step using a bus bar. Aim.

Another object of the present invention is to provide a high-quality, low-cost solar cell module having high conversion efficiency, a thin, lightweight solar cell module, and high quality.

[0014]

According to the present invention, there is provided a conductive substrate, a semiconductor layer provided on the substrate and having a photoelectric conversion function, a transparent conductive film provided on the semiconductor layer, and a conductive film provided on the transparent conductive film. In a solar cell module in which a plurality of solar cells composed of a plurality of current collecting electrodes provided in series are connected, the current collecting electrodes of one of the solar cells and the other of the adjacent solar cells are connected to each other. A member for series connection is interposed between the conductive base and the conductive member. The member for series connection includes a metal layer, a pair of conductive adhesive layers provided on one surface side of the metal layer at predetermined intervals, and And an insulating adhesive layer sandwiched between the conductive adhesive layers, wherein one of the pair of conductive adhesive layers is brought into contact with the current collecting electrode of the one solar cell, An adhesive layer is formed on the adjacent solar cell. There is positioned so as to each other becomes an insulating condition, characterized in that the other of the conductive adhesive layer of the pair of the conductive adhesive layer so as to contact with the other conductive substrate of the solar cell.

[0015] In this case, it is preferable that the conductive adhesive and the insulating adhesive constituting the serial connection member are pressure-sensitive adhesives.

The members for series connection are manufactured in the following procedure. First, a metal foil having a predetermined tape width or an insulating sheet on which a metal film is deposited is prepared. Next, using a dispenser, a conductive adhesive, an insulating adhesive, and a conductive adhesive are placed in that order from the sheet end position of the sheet having the tape width, and the respective films are made to have a uniform film thickness by squeezing.

The conductive adhesive used for the series connection member is preferably one in which fine powder of gold, silver, copper, nickel, carbon, or the like is dispersed in a binder polymer. Examples of the binder polymer include resins such as polyester, epoxy, acrylic, polyvinyl acetate, rubber, urethane, and phenol. In particular, if an acrylic or rubber pressure-sensitive adhesive is used, heat curing is not required, which can contribute to a reduction in man-hours.

As the insulating adhesive, an acrylic, silicone, or rubber-based pressure-sensitive adhesive is preferable.

As the metal layer, aluminum, copper,
Stainless steel or the like is preferred.

As the flat plate used in the manufacturing process of the solar cell module according to the present invention, a thin coated steel plate, a nylon resin sheet, a polyester resin sheet, or the like is suitable when sealed in the module. A PTFE sheet to which no adhesive is attached is preferable.

As the sealing resin, ethylene-vinyl acetate copolymer (EVA resin), polyvinyl butyral, and silicone resin are preferable.

Examples of the conductive substrate include stainless steel, aluminum, copper, and a carbon sheet.

Examples of the semiconductor layer having the photoelectric conversion function include pin junction amorphous silicon, pn junction polycrystalline silicon, CuIn ₂ Se ₂ / CdS, and the like. The semiconductor layer is formed by plasma CVD of silane gas or the like in the case of amorphous silicon, formed into a sheet of molten silicon in the case of polycrystalline silicon, and formed by electron beam evaporation, sputtering, or the like in the case of CuIn ₂ Se _2. .

As the transparent electrode, indium oxide,
Suitable are tin oxide, ITO, zinc oxide, titanium oxide, a crystalline semiconductor layer doped with a high concentration of impurities, and the like. Examples of the formation method include resistance heating evaporation, electron beam evaporation, sputtering, spraying, CVD, and impurities. Diffusion method etc. are mentioned.

[0025]

An example of a manufacturing process of a solar cell module 100 in which a plurality of solar cells 101 are serialized as shown in FIG. 1 will be described.

First, as shown in FIG.
The semiconductor layer 20 9 on the 4, after forming the transparent electrode layer 202, a conductive ink to form a collecting electrode 201 by screen printing, and cut into a desired size to prepare a solar cell 200 . Subsequently, each solar cell 2
00, the current collecting electrode layer 201 and the transparent electrode layer 20 along one end.
2. Each of the semiconductor layers 209 is removed, and a part of the surface of the conductive substrate 207 is exposed.

Each of the solar cells 200 manufactured as described above is arranged side by side between the electrode terminal tabs (104 shown in FIG. 1) on the flat plate 208 and in series between the adjacent solar cells. The connecting member 203 is attached. The flat plate 208 may be sealed together with the solar cell 200. FIG. 5 shows a member 503 for series connection.
1 shows a state in a plan view immediately after the application.

At the time of attaching the serial connection member 203, as shown in FIG. 2, the insulating adhesive 203b covers one end of one (left side in FIG. 2) solar cell 200. In addition, it is important to set the position and the pressing force. After the attachment, heat treatment is performed to complete the series connection.
Adhesive 203 used for series connection member 203
When b and 203c are pressure-sensitive adhesives, no heat treatment is required.

After that, as shown in FIG. 1, a lead wire is connected to the output terminal tab 104 and sealed with a sealing resin 105 to form a solar module 100 as a final product.
Is obtained.

As described above, it can be seen that the solar cell module of the present invention can be easily and quickly manufactured without performing complicated operations such as soldering and application of an insulating resin. Also,
A bus bar for concentrating current is not required, and the overall shape of the solar cell module can be flattened.

In FIG. 1, reference numeral 102 denotes an exposed portion of the conductive substrate, 103 denotes a tape-shaped member for series connection, and 106 denotes a current collecting electrode. In FIG. 2, reference numeral 207 denotes an exposed portion of the substrate;
Is a member for series connection, 203a is a metal layer, and 203c is a conductive adhesive.

FIG. 3 shows the connecting member 203 for series connection of FIG.
In FIG. 3, reference numeral 303 denotes a connection member for series connection, 303a denotes a metal layer, and 303b denotes an insulating member.
The conductive adhesive 303c is a conductive adhesive. FIG.
Reference numeral 501 denotes a solar cell, and 502 denotes an exposed portion of the substrate.

[0033]

Embodiments of the present invention will be described below in more detail.

(Example 1) First, an amorphous silicon layer having a thickness of 400 nm and having a pin junction was formed on a cleaned rolled stainless steel substrate by plasma CVD using a silane gas or the like by a roll-to-roll method.
0 nm ITO was formed by resistance heating evaporation. Next, a paste containing an ITO etching agent (ferric chloride, hydrochloric acid) was screen-printed and then heat-treated to remove a part of the ITO layer to divide the solar cell. Next, the ITO / pin junction amorphous silicon layer located at the wiring connection part of each separated solar cell is removed with a grinder to expose the stainless steel substrate surface, and the ITO removed portion is removed by YAG.
It was cut by laser light irradiation.

With respect to the cells, a current collecting electrode was formed by using a silver ink by a screen printing method, and a plurality of solar cells were obtained. As a member for series connection, an epoxy-based conductive adhesive (viscosity: 2000 poise) using silver particles as a filler in an aluminum foil having a width of 5 mm and a thickness of 0.1 mm is 1 mm wide.
A pressure-sensitive acrylic insulating adhesive having a width of 3 mm and the same epoxy-based conductive adhesive having a width of 1 mm were applied by a dispenser and squeezed to adjust the thickness to about 0.1 mm.

Next, three solar cells were arranged side by side between two copper tabs for terminal electrodes, a member for series connection was attached between the solar cells, and heat treatment was performed at 130 ° C. for 1 hour.

After the heat treatment, the PTFE sheet was removed, the element connected in series between the nylon sheet and the two EVA sheets was sandwiched, and laminated with a vacuum laminator to produce a module according to the present invention. Since the series connection is performed using a thin tape-shaped series connection member, the module can be flattened as a whole, and the module is rich in flexibility. This module is a standard light AM
It was placed under 1.5 and 100 mW / cm ² , and the open-circuit voltage was measured.

As described above, the conventional series connection process of the solar cells requires the complicated work of coating the stainless steel substrate, fixing the bus bar, and soldering. As described above, only the steps of attaching the tape-shaped connecting member and performing the heat treatment are required, so that the operation is extremely simplified.

(Embodiment 2) In this embodiment, first, as in Embodiment 1, a 400 nm-thick pin junction is formed on a cleaned rolled stainless steel substrate by plasma CVD using a silane gas or the like by a roll-to-roll method. After the amorphous silicon layer was formed, ITO having a thickness of 80 nm was formed by resistance heating evaporation. Further, a paste containing an ITO etching agent (ferric chloride, hydrochloric acid) was screen-printed and then heat-treated to remove a part of the ITO layer to divide the solar cell.

Subsequently, the surface of the stainless steel substrate in Example 1 was exposed by sandblasting, and the ITO-removed portion was cut by shearing. For the cell, a current collecting electrode was formed using a silver ink by a screen printing method to obtain a plurality of solar cells.

Next, the members for series connection were constructed as follows. First, aluminum was deposited on a polyester tape having a width of 5 mm and a thickness of 0.1 mm. The pressure-sensitive acrylic conductive adhesive was applied with a width of 1 mm, the pressure-sensitive acrylic adhesive with a width of 3 mm, and the pressure-sensitive acrylic conductive adhesive with a width of 1 mm. The conductive filler of the conductive adhesive is silver particles. Next, a copper tab for an extraction electrode and three solar cells were lined up on a PTFE sheet, and the member for series connection was attached to form a series connection.

As described above, in this embodiment, since both the conductive adhesive and the insulating adhesive are of the pressure-sensitive type, even heat treatment is unnecessary, and the simplification of the operation is further promoted as compared with the conventional connection method. it can.

Example 3 A plurality of solar cells were manufactured in the same procedure as in Example 2. Next, a pressure-sensitive acrylic conductive adhesive using aluminum particles as a filler in a copper foil having a thickness of 0.2 mm and a width of 6 mm is 2 mm wide, a pressure-sensitive rubber-based adhesive is 2 mm wide, and the above acrylic conductive adhesive is used. The same material as above was applied with a coater in a width of 2 mm to obtain a member for series connection. As described above, according to the present invention, since the current does not concentrate and flow in the series connection portion, the conductivity of the conductive filler can be reduced. Therefore, aluminum, carbon or the like may be used instead of expensive silver.

Next, the copper tab for the terminal electrode and the solar cell 3
The sheets were arranged on a 0.2 mm-thick coated steel sheet and connected by a series member. Also in this example, the series connection could be completed only by bonding the series members, which was extremely simple. Further, polyvinylidene fluoride (PVD)
F, manufactured by Dupont, Tedlar) sheet and an EVA sheet were stacked, and the coated steel sheet was laminated with a vacuum laminator to obtain a module. Since the module of the present embodiment is equipped with a back plate, the strength is increased, and the man-hour does not increase even if the back plate is attached.

(Embodiment 4) FIGS. 8 and 9 show a schematic configuration of a solar cell module according to Embodiment 4.
This module includes three solar cells 800a, 800
b and 800c are arranged side by side. As shown in FIG. 9, each solar cell has a lower electrode layer 802, a semiconductor layer 803, an upper electrode layer 804, and a comb as a collecting electrode on a conductive substrate 801. The mold electrode 805 was formed in that order.

Then, between adjacent solar cells, a bus bar electrode 807 is arranged under the conductive base 801 so as to straddle the bus bar electrode 807 to connect the solar cells in series, and the bus bar electrode 801 and each solar cell are connected. Was electrically connected to a comb-shaped electrode 805 via a conductor 806 such as a conductive paste.

Each of the solar cells 800a, 800b, 80
In No. 0c, an end face along the length direction of the bus bar of each cell was covered with an insulator 808 in order to prevent an electrical short circuit between the conductive base 801 and the bus bar electrode 807. As shown in the figure, the terminal connection bodies 80 connected to the respective conductive bases 801 are provided on the solar cells 800a and 800c on both sides.
9, 810 were provided respectively.

As described above, in the solar cell module according to the present embodiment, since the bus bar electrode 807 is located below the conductive substrate 801 and is located between the adjacent solar cells, the bus bar The shadow loss due to the bus bar electrode 807 can be reduced as compared with a conventional solar cell module in which the electrode 807 is located above the solar cell.

The bus bar electrode 807 is connected to the conductive base 8.
01, the area of the bus bar electrode 801 can be increased, and as a result, the thickness of the bus bar electrode 801 can be reduced.

The conductive substrate 801 includes stainless steel, aluminum, copper, a carbon sheet and the like, but a stainless steel substrate is preferably used.

As the lower electrode 802, Ti, Cr, M
o, W, Al, Ag, Ni, etc. are used, and examples of the forming method include resistance heating evaporation, electron beam evaporation, and sputtering.

For the photovoltaic layer, a semiconductor material known as a thin film solar cell can be used.

As the semiconductor layer 803, for example, a pin junction amorphous silicon layer, a pn junction polycrystalline silicon layer, Cu
And a compound semiconductor layer such as InSe ₂ / CdS.

The method for forming the semiconductor layer 803 is as follows.
In the case of an amorphous silicon layer, it can be formed by plasma CVD or the like in which a plasma discharge is generated in a raw material gas for forming a film such as a silane gas.

The pn junction polycrystalline silicon layer is
For example, it is formed by a film forming method of forming a film from molten silicon. In addition, the CuInSe ₂ /
CdS is formed by an electron beam evaporation method, a sputtering method, an electrodeposition method (deposition of an electrolytic solution by electrolysis), or the like.

As a material used for the upper electrode layer 804,
In ₂ O ₃ , SnO ₂ , In ₂ O ₃ —SnO ₂ , ZnO, Ti
There are O ₂ , Cd ₂ SnO ₄ , crystalline semiconductor materials doped with impurities at a high concentration, and the like. Examples of the formation method include resistance heating evaporation, electron beam evaporation, sputtering, spraying,
There are a CVD method, an impurity diffusion method, and the like.

For the comb-shaped electrode 805, a material having higher conductivity than the upper electrode 804 can be used. For example, a metal electrode, a conductive electrode in which a metal and a polymer binder are dispersed, and the like can be given. In general, a metal paste in which a metal powder and a polymer resin binder are in a paste state is used. These metal pastes are usually formed on a transparent electrode by a screen printing method. Among these metal pastes, silver paste is preferable in consideration of conductivity and cost, but is not limited thereto.

The bus bar electrode 807 is not particularly limited, but usually, a metal electrode, a conductive paste, or the like is used, and the shape thereof is a linear shape, a tape shape, or the like.

The conductor 806 is not particularly limited, but a conductor such as a conductive metal paste, solder, or a metal wire is usually used.

As the insulator 808, for example, an insulating tape such as a polyester tape or an insulating resin such as an epoxy resin or an acrylic resin which is cured by heat or light may be used.

Embodiment 5 This embodiment is shown in FIGS. 10 and 11 and uses a stainless steel substrate as the conductive substrate.

First, as a conductive substrate (similar to the conductive substrate 801 of Example 5 shown in FIG. 9), a 0.2 mm thick stainless steel foil whose surface was washed was prepared.
Next, the lower electrode (similar to the conductive substrate 802 shown in FIG. 9) was formed on the stainless steel foil by 5000 °.
Was formed at a substrate temperature of 350 ° C. by a sputtering method. Then, Zn
On the O film, an n-type a-Si layer of 150 ° and an i-layer of 4000 °
Three photoelectric conversion layers (similar to the conductive substrate 803 shown in FIG. 9) as a pin junction semiconductor layer of a type a-Si layer and a 100-degree p-type a-Si layer are continuously formed in that order. did. The gas used at this time was SiH ₄ gas / PH ₃ gas / H ₂ gas, SiH ₄ gas / H ₂ gas, SiH ₄ gas / BF
₃ gas / H ₂ gas, and the substrate temperature was maintained at 250 ° C.

Thereafter, a 700 ° In ₂ O ₃ —SnO ₂ film (ITO film) as a transparent electrode (similar to the conductive substrate 804 of Example 5 shown in FIG. 9) was formed on the semiconductor layer.
In and Sn were formed by resistance heating evaporation at 200 ° C. in an oxygen atmosphere.

Next, the rolled stainless steel substrate thus formed was cut into a pattern as shown in FIG. 10 to obtain three solar cells 1001 to 1003. Next, a paste containing an ITO etching material (FeCl ₃ , HCl) is screen-printed and then heated and washed to remove the ITO layer where the paste is printed (removed portion 10).
11), electrical separation between the upper electrode and the lower electrode was ensured.

Next, the current-collecting comb electrode 1012 having a width of 0.3 mm on the ITO layer was formed by screen-printing a silver paste.

Subsequently, each of the solar cells 1001 to 100
3 to each other, to insulate them from each other.
It was covered with a 1 mm thick polyester tape 1013. In this case, the polyester tape 1013 was applied so as to be located inside the ITO-removed portion 1011 in order to electrically separate the upper electrode and the lower electrode.

Next, a copper foil 10 serving as a bus bar electrode having a thickness of 0.1 mm and a width of 5 mm is provided below the conductive base of each solar cell and between adjacent solar cells.
14 was placed.

Here, the separation distance between the solar cells is 1.
0 mm, and the solar cell and the bus bar electrode were temporarily fixed with an adhesive tape 1018.

Next, the bus bar electrodes 1014 located over the solar cell 1001 and the solar cell 1002 and over the solar cell 1002 and the solar cell 1003, respectively, are projected to the substrates of the solar cells 1002 and 1003. The sections were electrically connected by spot welding. Thus, the solar cells 1001 to 1003 were connected in series.

A copper tab 1016 for taking out a terminal from the negative electrode side is connected to the projection of the solar cell 1001 by welding, and a copper tab 1017 for taking out a terminal from the positive side is connected to the solar cell. A bus bar 1014 connected to the comb electrode of the cell 1003 was connected by soldering.

Next, the solar cell module manufactured above was mounted on a PET film 1020 having a thickness of 0.3 mm, and then sealed with a fluororesin and EVA (ethylene-vinyl acetate copolymer). .

In the above-described solar cell module, since the bus bar electrode is located below the conductive base and is straddled between adjacent solar cells, the bus bar electrode is located above the solar cell. The shadow loss due to the bus bar electrode can be reduced as compared with the solar cell module of (1).

(Embodiment 6) The present embodiment has the configuration shown in FIG. 12, but in the configuration of Embodiment 5 described above, the comb-shaped electrode 1012 and the bus bar electrode 1014 on the solar cell are electrically connected. A copper wire 1201 having a diameter of 0.2 mm was used as a connection body for connection. Other configurations were the same as those of the fifth embodiment.

That is, in FIG.
Are for electrically connecting the comb-shaped electrode 1012 and the bus bar electrode 1014, and are arranged in an arc between the ends of adjacent solar cells. The copper wire 1201 and the comb electrode 10
12 and the copper wire 1201 and the bus bar electrode 101
The connection with No. 4 was performed using an adhesive silver ink 1002.

As in the sixth embodiment, the copper wire 120 serving as a connection body is used.
When the solar cell module was constructed using No. 1, the bending resistance of the solar cell module could be improved in addition to the effect of the fourth embodiment.

(Example 7) In this example, a photocurable resin was used in place of the polyester tape 1013 as an insulating material at the end of the solar cell in the structure of Example 5. Other configurations were the same as those of the fifth embodiment. As the photocurable resin, TB3042C (registered trademark) manufactured by Three Bond Co., Ltd. was used.
After forming a resin thin film by dipping to the inside of
It was cured by irradiating it with ultraviolet rays in an amount of 500 mj / cm ² . The thickness of the photocurable resin was about 30 microns.

As in the present embodiment, by forming the thin film insulating material by photo-curing, the separation distance between the solar cells can be reduced to 0.5 mm, the flatness is excellent, and the shadow loss is reduced. A small number of solar cell modules could be manufactured.

(Embodiment 8) This embodiment 8 corresponds to FIGS.
4 has a configuration shown in FIG.
0 to 1322 are the lower electrode layer 1 on the conductive base 1301.
302, a semiconductor layer 1303, an upper electrode layer 1304, and a comb-shaped electrode 1305 which is a current collecting electrode of the upper electrode layer 1304 were formed. The three solar cells were arranged in parallel, and a plate-shaped bus bar electrode 1307 was arranged at the end of each solar cell.

In order to connect three solar cells in series, the bus bar electrode 1307 and the comb electrode 1305 were electrically connected via a conductor 1306 such as a conductive paste.

Here, each end of each solar cell was covered with an insulator 1308 so that the conductive base 1301 and the bus bar electrode 1307 were not electrically short-circuited. In the figure, 1309 and 1310 are solar cells 13
20 and 1322 are connection bodies for taking out terminals from the conductive substrate.

As can be understood from FIG. 13, in the solar cell module of the present invention, since the bus bar electrodes 1307 are located between the solar cells, the total thickness of the conventional solar cell module is at least equivalent to the thickness of the bus bar electrodes. I was able to make it thinner.

The conductive substrate 1301 of this embodiment may be any of stainless steel, aluminum, copper, carbon sheet, etc., but preferably uses a stainless steel substrate.
As the lower electrode provided on the base, Ti, Cr,
Mo, W, Al, Ag, Ni, or the like is used, and examples of the forming method include resistance heating evaporation, electron beam evaporation, and sputtering.

For the photovoltaic layer of the solar cell, a known semiconductor material generally used as a thin-film solar cell was used. As the semiconductor layer 1303 of the solar cell,
For example, a pin junction amorphous silicon layer, a pn junction polycrystalline silicon layer, and a compound semiconductor layer such as CuInSe ₂ / CdS can be given. As a method of forming the semiconductor layer, in the case of an amorphous silicon layer, a plasma C that generates a plasma discharge in a raw material gas for forming a film such as a silane gas is used.
It can be formed by VD or the like. The pn junction polycrystalline silicon layer is formed by, for example, a film forming method of forming a film from molten silicon.

The CuInSe ₂ / CdS was formed by a method such as an electron beam evaporation method, a sputtering method, and an electrodeposition method (deposition of an electrolytic solution by electrolysis).

Materials used for the transparent electrode 1304 of the solar cell include In ₂ O ₃ , SnO ₂ , and In ₂ O ₃ -Sn.
There are O ₂ , ZnO, TiO ₂ , Cd ₂ SnO ₄ , crystalline semiconductor materials doped with impurities at a high concentration, and the like. Examples of the formation method include resistance heating evaporation, electron beam evaporation, sputtering, spraying, CVD, There is an impurity diffusion method and the like.

As the comb electrode 1305, the upper electrode 13
For example, a metal electrode, a conductive electrode in which a metal and a polymer binder are dispersed, and the like can be used. In general, a metal powder and a polymer resin binder are formed into a paste. Metal paste is used. These metal pastes are usually formed on the transparent electrode 1304 by a screen printing method. Among these metal pastes, silver paste is preferable in consideration of conductivity and cost, but is not limited thereto.

The bus bar electrode 1307 is not particularly limited, but usually, a metal electrode, a conductive paste, or the like is used, and the shape thereof is a linear shape, a tape shape, or the like.

The conductor 1306 is not particularly limited, but usually, a conductor such as a conductive metal paste, solder, or a metal wire is used.

As the insulating material 1308, for example, an insulating tape such as a polyester tape or an insulating resin such as an epoxy resin or an acrylic resin obtained by thermosetting or photo-curing can be used.
It is not particularly limited to these.

(Embodiment 9) This embodiment relates to an amorphous silicon solar battery cell using a stainless steel substrate as a conductive substrate, and has a structure shown in FIGS.

First, a 0.2 mm thick stainless steel foil whose surface was washed was prepared as a conductive substrate for a solar battery cell.

Next, an aluminum film having a thickness of 5000 .ANG. And a 700 .ANG.
Was formed at a substrate temperature of 350 ° C. by a sputtering method. Thereafter, the substrate temperature was maintained at 250 ° C., and Zn
A 150 ° n-type a-Si layer, a 4000 ° i-type a-Si layer, and a 100 ° p-type a-Si layer are formed on an O film by SiH ₄ gas / PH ₃ gas / H ₂ gas and SiH ₄ gas, respectively. /
H ₂ gas and SiH ₄ / BF ₃ gas / H ₂ gas were used to form a continuous photoelectric conversion layer, thereby forming a three-layer photoelectric conversion layer as a pin junction semiconductor layer.

Thereafter, in order to form a 700 ° In ₂ O ₃ —SnO ₂ film (ITO film) as a transparent electrode on the semiconductor layer, resistance heating evaporation of In and Sn was performed at 200 ° C. in an oxygen atmosphere. .

Next, the rolled stainless steel substrate thus formed was cut into a pattern as shown in FIG. 15 to obtain three solar cells 1501 to 1503. Next, after a paste containing an ITO etching material (FeCl ₃ , HCl) is screen-printed in a predetermined pattern, the portion where the paste is printed is removed by heating and washing to remove the ITO layer (removed portion 1511). The electrical separation between the electrode and the lower electrode was ensured.

Next, a 0.3 mm wide current-collecting comb electrode 1512 was formed on the ITO by screen printing of a silver paste.

Then, in order to insulate the end faces of these solar cells close to the adjacent solar cells, 0.1
Coated with a millimeter thick polyester tape 1513. At this time, the polyester tape 1513 is used to remove the ITO removal portion 151 to electrically separate the upper electrode and the lower electrode.
No. 1 was placed so as to be located inside.

Subsequently, the separation distance between the three solar cells arranged side by side was 0.6 mm, and a tin-plated copper wire 1514 having a diameter of 0.4 mm was located in each gap.

Next, the comb-shaped electrode 151 of the solar cell is described.
2 and one end of the bus bar electrode 1514 are connected with the adhesive silver ink 15
15 and electrically connected.

Further, bus bar electrodes 151 located between solar cell 1501 and solar cell 1502 and between solar cell 1502 and solar cell 1503 are provided.
4 were electrically connected to each other by spot welding to the projections of the substrate, and the respective solar cells were connected in series.

Also, a copper tab 1516 is connected to the protruding portion of the solar cell 1501 to take out the terminal from the negative electrode side, and a copper tab 1517 is connected to the comb-shaped electrode of the solar cell 1503 to take out the terminal from the positive electrode side. Busbar electrode 1
514 were each connected by solder.

Next, these solar cell modules were placed in 0.
After being placed on a 3-mm-thick PET film 1520, the solar cell module was fabricated by resin sealing with a fluororesin and EVA (ethylene-vinyl acetate copolymer).

Therefore, in the manufactured solar cell module, the bus bar electrode was located between the solar cells,
The total thickness can be reduced by at least the thickness of the bus bar electrode.

(Embodiment 10) This embodiment is different from the embodiment 9 described above.
In Example 1, the bus bar electrode was formed of a tin-plated copper tape having a width of 0.6 mm and a height of 0.2 mm, and the separation distance between the solar cells was set to 0.8 mm. Other configurations and manufacturing methods are the same as those in the ninth embodiment.

In the solar cell module according to the present embodiment, since the thickness of the conductive base is the same as the thickness of the bus bar electrode, the bus bar electrode never projects from the solar cell surface. As a result, a solar cell module having high flatness and excellent scratch resistance was able to be manufactured.

(Example 11) In this example, a galvanized steel sheet was used in which a photocurable resin was used instead of the polyester tape, which is the insulating material on the end face of the solar cell, and the surface was insulated instead of the PET resin. Was used. Other configurations and manufacturing methods are the same as those in the tenth embodiment.

The photocurable resin is a product of T
Using B3042C (registered trademark), the end face of the solar cell is dipped to the inside of the portion 1511 where the ITO is removed by etching to form a resin thin film, and then 1500 mj.
The composition was cured by irradiating an ultraviolet ray in an amount of / cm ² to obtain an insulating material.

The thickness of the photocurable resin was about 30 microns. In this example, the separation distance between the solar cells was set to 0.7 by making the thin film insulating material by photocuring.
It was possible to produce a solar cell module having an excellent flatness, a small shadow loss, and a high bending resistance.

[0108]

As described above, according to the present invention, a thin series connection, flat and flexible as a whole, and a full-surface connection eliminate current concentration and reduce power loss. Even if some parts are detached, the series connection is maintained and the reliability is high, and the steps of applying insulating resin, soldering, attaching the bus bar, etc. are not required, respectively, and the connection can be made only on the surface, facilitating the automation of the process . That is, as described above, the solar cell module according to the present invention is excellent in productivity, reliability, and appearance, and has high industrial utility value.

[Brief description of the drawings]

FIG. 1 is a plan view showing a solar cell module according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a series connection portion of the solar cells in FIG.

FIG. 3 is a sectional view of the serial connection member shown in FIG. 1;

FIG. 4 is a side view showing a configuration example of an amorphous solar battery cell.

FIG. 5 is a plan view showing a part of a serialization process of the solar cell module according to the present invention.

FIG. 6 is a plan view of a conventional solar cell module.

FIG. 7 is a plan view showing a serialization process of the conventional solar cell module shown in FIG.

FIG. 8 is a plan view showing a solar cell module according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view taken along the line PP of FIG. 8;

FIG. 10 is a plan view showing a solar cell module according to a fifth embodiment of the present invention.

FIG. 11 is a sectional view taken along line QQ in FIG. 10;

FIG. 12 is a view of a solar cell module according to a sixth embodiment of the present invention.

FIG. 13 is a view of a solar cell module according to a seventh embodiment of the present invention.

FIG. 14 is a sectional view taken along the line RR in FIG. 13;

FIG. 15 is a view of a solar cell module according to a ninth embodiment of the present invention.

FIG. 16 is a sectional view taken along the line SS in FIG. 15;

FIG. 17 is a plan view showing a conventional solar cell module.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 solar cell module 101 solar cell 102 exposed portion of conductive substrate 103 tape-shaped serial connection member 104 terminal electrode tab 105 sealing resin 106 current collector electrode 200 solar cell 201 collection Electrode, 202 transparent conductive film, 203 series connection member, 203a metal layer, 203b insulating adhesive, 203c conductive adhesive, 204 conductive substrate, 207 exposed portion of substrate, 209 semiconductor layer, 303 series connection member 303a metal layer, 303b insulating adhesive, 303c conductive adhesive, 801 conductive base, 802 lower electrode layer, 803 semiconductor layer, 804 upper electrode layer, 805 comb electrode, 806 connection conductor, 807 busbar electrode, 800a, 800b, 800c solar cells, 1001-1003 solar cells 1011 ITO layer removed portion, 1012 Comb electrode for current collection, 1013 Polyester tape, 1014 Copper foil (busbar electrode), 1018 Adhesive tape, 1016 Copper tab, 1201 Copper wire (connector), 1002 Adhesive silver ink, 1013 Polyester tape (insulating material), 1320 to 1322 solar cells, 1301 conductive substrate, 1302 lower electrode layer, 1303 semiconductor layer, 1304 upper electrode layer, 1305 comb-shaped electrode (collecting electrode), 1307 plate-shaped busbar electrode, 1306 conductor (conductive paste), 1308 insulator, 1309, 1310 solar cells 1320, 1322
1515 to 1503 solar cell, 1511 ITO layer removed portion, 1512 current-collecting comb electrode, 1513 polyester tape, 1514 tinned copper wire (busbar electrode), 1515 Adhesive silver ink, 1516, 1517 Copper tab, 1701 Stainless steel substrate, 1702 Substrate exposed part, 1703 Current collecting electrode, 1704 Bus bar.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-56-94785 (JP, A) JP-A-4-116986 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 31/04

Claims (2)

(57) [Claims] 1. A conductive substrate, a semiconductor layer provided on the substrate and having a photoelectric conversion function, a transparent conductive film provided on the semiconductor layer, and a plurality of current collecting electrodes provided on the transparent conductive film In a solar cell module in which a plurality of solar cells consisting of are connected in series, a series connection is made between the current collecting electrode of one of the adjacent solar cells and the conductive base of the other solar cell. A connection member is interposed, the connection member for series connection is a metal layer, a pair of conductive adhesive layers provided at a predetermined interval on one surface side of the metal layer, and an insulating material sandwiched between the two conductive adhesive layers. And a conductive adhesive layer, the conductive adhesive layer of one of the pair of conductive adhesive layers is brought into contact with the current collecting electrode of the one solar cell,
The insulating adhesive layer is positioned so that the adjacent solar cells are insulated from each other, and the other conductive adhesive layer of the pair of conductive adhesive layers is used as a conductive base of the other solar cell. A solar cell module characterized by contacting with a solar cell module. 2. The solar cell module according to claim 1, wherein the conductive adhesive and the insulating adhesive constituting the series connection member are pressure-sensitive adhesives.