JP3121810B1 - Thin film solar cell module and method of manufacturing the same - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To reduce the area of a portion contributing to photovoltaic power in the occupied area of a substrate-integrated thin-film solar cell module in which elements are formed directly on a transparent insulating substrate, without reducing the area between bus regions or between bus regions. From the power supply connection area to the terminal box or the like with high reliability and ease. SOLUTION: A wiring from a bus area is made of a solder-plated copper foil, and an insulation between an element surface and the solder-plated copper foil is buried with a filler.
Perform with a synthetic fiber non-woven fabric sheet that is heat-resistant to ℃.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin-film solar cell module and a method of manufacturing the same, and more particularly, to a thin-film solar cell having a photovoltaic element directly formed on a transparent insulating substrate or a combination of a small number of thin-film solar cells. The present invention relates to a configuration for taking out electrodes of a thin film solar cell module to be used and a method for assembling the same.

[0002]

2. Description of the Related Art Photovoltaic power generation has become popular as a means for solving environmental problems such as depletion of resources or an increase in the amount of generated carbon dioxide, and the use of semiconductor materials such as silicon is small. Attention has been focused on thin-film solar cells.

[0003] Thin-film solar cells have a problem that the efficiency of converting light into electric power is several percent lower than that of a solar cell using a crystal substrate which has been practically used in the past. In environments where there are limited
Increasing the area contributing to power generation with respect to the area occupied by the solar cell module is regarded as important as a means for filling the efficiency gap. In the case of a solar cell using a crystal substrate, one solar cell is formed on one crystal substrate, and several tens of the solar cells are connected to form a solar cell module. Of the area of the solar cell module, the area of the solar cell module that is used for wiring the power of the solar cell element to the connection means such as a terminal box is 70% to 80%. In contrast, a thin-film solar cell module has been proposed in which a solar cell element is formed directly on a transparent insulating substrate and connected on the substrate (hereinafter referred to as a substrate-integrated solar cell module). Can be realized up to about 90% of the area occupied by the module.

[0004] The structure of a solar cell portion of a substrate-integrated solar cell and a method of manufacturing the same are disclosed in US Pat.
No. 2092. A transparent conductive film is formed on a transparent insulating substrate such as glass, separated into individual strip-like photovoltaic regions by laser processing lines, and a p-type, i-type
And n-type amorphous silicon are formed on the entire surface to form a photovoltaic semiconductor layer. A connection groove for connecting to the next element is made by laser processing at a position shifted in parallel with the first processing line. Further, after forming the back electrode layer, a back electrode separation groove is formed in parallel with the connection groove and on the side opposite to the separation groove of the transparent electrode. Through these steps, a thin-film solar cell in which a plurality of strip-shaped photovoltaic elements are connected in series to one substrate is formed.

[0005] A bus means is provided at or near the terminal end of the connection to take out the electric power of the thin-film solar cell. Since the bus means does not contribute to power generation, a good conductor is provided in a strip-shaped area (bus area) slightly narrower than the photovoltaic element so that power can be more easily collected. As a good conductor, for example, a method in which a paste in which metal particles such as glass frit are dispersed is applied to the area as disclosed in JP-A-3-171675, or a solder-plated copper as disclosed in JP-A-9-83001. There is a method of connecting the foil with ceramic solder.

[0006] Regardless of the crystal substrate or the thin film, the solar cell module has connection means for supplying electric power to the outside, and a terminal box is used as a specific example thereof. The terminal box has a terminal therein, and a wire drawn from the inside of the solar cell module is connected to the terminal, and a power output cable or the like is connected via the terminal.

[0007] The connection structure between the bus area and the external connection means includes a method of connecting a copper foil on a transparent support used in a crystal substrate solar cell on the same plane as the substrate, and a method disclosed in Japanese Unexamined Patent Application Publication No. Hei. As in 171675, there is a method in which a paste in which metal particles such as glass frit are dispersed is applied linearly to a region on the transparent insulating substrate where no photovoltaic element exists mainly in the peripheral portion, and wiring is performed. The method of (1) requires a space for wiring, and thus has a problem in that the area of the power generation region is deprived of the limited area occupied by the solar cell module.

To solve such a problem, Japanese Patent Application Laid-Open No.
No. 326497 proposes that a wiring for connecting a bus region and a means for supplying electric power to the outside in a filler for sealing an element is formed by a copper foil or the like plated with solder. In this case, an insulating film for securing insulation between the copper foil and the photovoltaic element is used, and a structure in which a filler and a back cover are installed thereon is disclosed as a conventional example. A configuration covered with a film is disclosed as an example.

The former method is specifically shown in FIG.
Bus areas 3, 3 'for collecting positive and negative power are provided on the thin-film solar cell 100, and solder-plated copper foils 4, 4' are provided thereon.
Is provided, and an insulating film 7 is laid between the solder-plated copper foils 4 and 4 'at positions corresponding to positions where electrode extraction portions of a terminal box as connection means for supplying power to the outside are arranged, Two solder-plated copper foils 5, 5 'each having one end connected to the solder-plated copper foils 4, 4' are laid on the insulating film to form wiring. Subsequently, a film 9 of a filler for adhering the back surface protective cover 13 placed thereon onto the glass substrate 1 is superimposed on the back surface protective cover in this order. The back cover 13 is provided with an opening for taking out an electrode, and the solder-plated copper foils 5, 5 'are led out of the opening to the outside of the back cover, and in this state, they are heat-pressed using a vacuum laminator. Is fixed.

FIG. 3 shows the method of the embodiment of the present invention. As shown in FIG. 4, a copper foil 45 covered with an insulating film 15 is used instead of the solder-plated copper foils 5 and 5 '.
45 'and a configuration without using the insulating sheet 7 used in FIG.

[0011]

In the above-mentioned prior art, the method disclosed in Japanese Patent Application Laid-Open No. 3-171675 has a problem that a large area is lost due to wiring and the characteristics as a solar cell module are deteriorated.

The structure of JP-A-9-326497 proposed as an alternative method is easy to assemble, but observing the completed module, the method shown in FIG. It was found that no material was present, and a gap was formed when the solder-plated copper foil was pulled from the opening. In the structure of FIG. 3, the coated copper foil 45,
Similarly, a gap was formed between 45 and the photovoltaic element.

When these thin-film solar cell modules were put into an environmental tester of 85% humidity and 85 ° C. and observed for 1000 hours, moisture entered the above-mentioned gap, and the back electrode near the gap was observed. Was corroded. Also,
When the insulating film 15 covered the copper foil with an adhesive other than the filler, the filler 9 around the insulating film 15 turned yellow.

A solar cell module is installed on a rooftop of a house or the like and is easily affected by the environment, for example, the temperature always rises to about 80 ° C., and a point that a service life of about 20 years is required due to its price and sales form. , Extremely strict reliability items are required. In order to cope with this, it is necessary to avoid using materials other than those whose reliability is guaranteed, and to completely fill the inside of the solar cell module with a filler and to have no voids.

In addition to satisfying such strict reliability items, it is necessary to keep the price low in order to spread the photovoltaic power generation, and it is necessary to realize the above items with a simple structure and method. .

[0016]

Means for Solving the Problems The inventor of the present invention has improved the means for satisfying the above conditions day and night starting from the structure disclosed in Japanese Patent Application Laid-Open No. 9-326497. I found a way.

That is, according to the present invention, sealing means including a filler and a protective cover for protecting the surface on which the thin-film solar cell is formed, and a connection for supplying electric power generated by the thin-film solar cell to the outside. In the thin-film solar cell module including the means, the wiring from the bus region to the connection means is embedded in the filler, and the space between the wiring and the back electrode layer is filled with the same material as the filler for embedding the wiring. A glass nonwoven fabric sheet or a 180 ° C heat-resistant synthetic resin nonwoven fabric sheet was embedded in the material.

As a structure for realizing this structure, specifically, the filler is an uncured sheet such as ethylene-vinyl acetate copolymer (EVA) or polyvinyl butyral (PVB) used in a vacuum laminating method. Supplied by
In the case of using a type that is melted by heating and thermally cross-linked, the area including the space between the wiring connecting the connection means (terminal box) for supplying power from the bus area and the back electrode surface of the solar cell is filled. Material sheet and a glass non-woven fabric sheet or a 180 ° C. heat-resistant synthetic resin non-woven fabric sheet, and in that region, a transparent insulating substrate, a thin-film solar cell element, a filler, a glass non-woven fabric sheet or a 180 ° C. heat-resistant synthetic fiber non-woven fabric sheet, wiring (copper) As a configuration in which a foil), a filler covering the entire surface, and a back cover covering the entire surface are sequentially laminated, a method of deaeration, heating, and pressure bonding by a vacuum lamination method is implemented as one method.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments will be described below with reference to the drawings. The contents described here are for explaining the form, and the present invention is not limited to the form. The present invention can be applied to another form as long as the technical idea is reflected.

[Thin Film Solar Cell] FIG. 5 is a sectional view of an example of a thin film solar cell used in the present invention, and FIG. 6 is a top view.

Transparent insulating substrate 1 used in thin-film solar cell
Glass or heat-resistant plastic is used.
For example, SiO2 is formed on this substrate so that impurities of the substrate do not diffuse into the layer thereabove. A transparent electrode layer is formed on this.

As the transparent electrode layer 16, SnO2 grown in a manner that irregularities are formed by the apex angles of crystal grains is preferably used. As a forming method, a thermal CVD method is generally used.

The transparent electrode layer is provided with grooves 18 by using a laser processing method or the like, and strip-shaped individual regions 17 are formed.

A semiconductor layer 19 is formed thereon. As the semiconductor layer, a photovoltaic junction of amorphous silicon, thin-film polycrystalline silicon, CIS, CdTe, or the like is appropriately formed. Also, the material of the transparent electrode is appropriately selected from those suitable for these semiconductors.

These semiconductor layers are provided with grooves 21 for connection to an adjacent photovoltaic element.

On the semiconductor layer 19, a back electrode layer 22 is formed. As the back electrode layer, an electrode in which a transparent conductive material such as ZnO and a high light reflective metal such as Ag are combined is preferably used.

These back electrode layers 33 become individual electrodes 23 by the grooves 24. With this configuration, the unit elements 28 each having a semiconductor sandwiched between the transparent electrode and the back electrode are connected in series.

At both ends where these elements 28 are connected, bus areas 3 and 3 'for collecting power are provided. In this region, a plurality of grooves 25 for exposing the transparent electrode layer are provided, and ceramic solder bumps 26 are discretely formed in that portion. Ceramic solder contains rare earth elements so that it can be bonded to a transparent electrode or ceramic, and is commercially available from Senju Metal under the trade name of Cerasolza.

The solder plated copper foil 4 is connected to the bump 26. The solder-plated copper foil 4 is formed by coating a copper foil having a thickness of about 0.2 mm and a width of several mm with ordinary eutectic solder. This coating has the effect of improving the corrosion resistance and has the effect that solder connection can be easily performed simply by arranging the copper foil on the bump and pressing the copper foil on the copper foil with a solder iron. As a result, flux, which is an acid-based material, becomes unnecessary,
Since there is no problem of flux remaining in the sealing module, which is a conventional problem, it is preferable in terms of reliability.

In the peripheral region 27 of the substrate 1, there is a region in which all the upper layers do not exist, or by providing a groove in which all the upper layers are removed, it is possible to provide electrical insulation and
Due to the effect of increasing the adhesive force of the filler in this region, air and moisture are isolated from the surroundings.

When viewed from the surface where the elements are formed, as shown in FIG. 6, the back electrodes of the strip-shaped solar cell elements 28 are seen side by side at the center of the substrate to form the power generation region 2 and both ends thereof. Have bus areas 3 and 3 ', and a peripheral area 27 surrounding them.

The solder-plated copper foil 4 on the bus area
4 'is adjusted and connected so as to form a slight gap so that the filler fills the gap between the copper foil and the element surface.

[Wiring] The position of the terminal box as a means for supplying power from the solar cell module to the outside can be arbitrarily selected depending on the application. However, in the case of a crystal substrate module currently on the market, the short side of the terminal box is short. In many cases, it is located several centimeters from the edge of the glass surface near the center. Here, a description will be given with reference to FIGS. 7 and 8 assuming that the terminal box is arranged at a position 5 cm from the center of the short side.

In this case, first, as shown in FIG. 8 (b), 5 ′ from the end of the board of the 3.3 ′ solder-plated copper foils 4 and 4 ′ on the bus area.
The other solder-plated copper foils 5, 5 'are connected at the position of cm.
These solder-plated copper foils 5, 5 'are selected to be optimal for connection with the metal fittings of the terminal box. According to the inventor's experience, the width of the solder-plated copper foils 4, 4' in the bus area is relatively long. It is preferable that the width is smaller than 3 mm to facilitate the process, and it is preferable that the width be larger than 1 mm in order to secure the adhesion strength of the solder to the solder bump to 1 kg or more. Also, solder-plated copper foil for connection to the terminal box 5,
5 'is preferably wider than the solder-plated copper foil in the bus area in order to secure the strength, and the width of the connection terminal inside the box is about 7 mm, so that about 5 mm is preferably used. The thickness of this copper foil is set at 0.
A thickness of 2 mm or less is preferred.

The connection between the solder-plated copper foils 4, 4 'in the bus area and the solder-plated copper foils 5, 5' for routing is made by overlapping the two at the place to be connected and holding the solder on the copper foil with a soldering iron while holding down. Melt and solder. The soldering strength is required to be at least 1 kg, but in order to secure this strength, the solder thickness on the solder-plated copper foil needs to be 50 μm or more, and preferably 0.1 mm. It is possible to add more solder because securing the amount of solder increases the soldering strength, but if flux (soldering for solder) is included, there is a risk of corroding the metal. It has been found that it is effective to secure the thickness of the solder plating and to connect only with the plated solder.

The cause of the decrease in solder strength when the amount of solder is small is that the copper foil surface has irregularities of 0.1 mm or more with respect to the contact surface, and if there is not enough solder to fill in the irregularities, the solder joint will be surface This is because it is not a shape but a dot shape. [Glass non-woven fabric sheet or 160 ° C. heat-resistant synthetic fiber non-woven fabric sheet] A glass non-woven fabric sheet embedded in a filler is provided between a wiring from a bus area to a connection means for supplying electric power to the outside and an element surface of a solar cell. Or 160 ° C
A heat-resistant synthetic resin nonwoven fabric sheet 7 is provided.

As the filler 9 of the solar cell module, an ethylene / vinyl acetate copolymer (EVA) is generally used. Further, as a material of the back surface protective cover 13, a fluorine-based film is used.
r is common, and Ted is used to prevent moisture permeation.
A three-layer structure of ler / Al foil / Tedler is preferably used. As a result of a comprehensive study of the materials and structures of solar cell modules using crystal substrates by the Jet Propulsion Laboratory (JPL) of the United States in the early 1980s,
It has been found as the most reliable combination and has been used almost as an industry standard for the next 20 years. In the present invention, this combination is preferably used, but it is cheaper than each company for the past 20 years,
Alternatively, alternatives with improved reliability are being developed, and these are also used as appropriate.

As the glass nonwoven fabric sheet or the 160 ° C. heat-resistant synthetic fiber nonwoven fabric sheet 7, it is preferable to use a material whose reliability has already been confirmed from the viewpoint of reliability.

It has been found that the glass nonwoven fabric has the property that the permeability of the filler is extremely good, and that insulation can be reliably obtained. Also, CranesGlas23
Although it is a specific product of 0, it has been proved that good characteristics can be obtained by the above-mentioned Jet Propulsion Laboratory test. Of course, in recent years, long-fiber glass fibers are bound with more reliable acryl or the like, and those subjected to a primer treatment in order to improve the adhesiveness with the resin are selected as appropriate.

In recent years, synthetic fiber nonwoven fabrics having heat resistance have come to be sold for the electronics industry. These use fibers having heat resistance of about 160 ° C. such as acrylic fibers. The adhesiveness with the filler is improved as compared with the glass nonwoven fabric.

The thickness of the glass non-woven fabric sheet or the 160 ° C. heat-resistant synthetic fiber non-woven fabric sheet is larger than that of the resin film in consideration of the fact that the volume is reduced by the pressing in the vacuum laminating step. Preferably 0.1 to
O. A 4 mm one is used.

In the manufacturing process, for insulation between the solder-plated copper foil wiring between the bus area and the terminal box and the solar cell element, a laminate of a glass nonwoven fabric 7 and one filler sheet 6 is inserted. By doing so, the filler is melted during vacuum lamination, and the nonwoven fabric is completely impregnated. Moreover,
A space is completely maintained between the solder-plated copper foils 5, 5 'and the element surface 2 of the solar cell, and there is no possibility that both will touch. Further, since the glass nonwoven fabric is mainly made of glass and has a refractive index of 1.5, which is almost the same as the refractive index of the filler, it becomes transparent when impregnated with resin. Solar cell 100
There is a portion 24 where the semiconductor and the back electrode layer do not exist, and since this portion can be seen through from the light incident side,
In order to conceal the solder-plated copper foil, it is preferable to use the filler 6 colored in the same color as the color of the back protective cover on the side in contact with the filler.

It is necessary to make the width of the glass nonwoven fabric sheet or the synthetic fiber nonwoven fabric sheet 7 resistant to 160 ° C. larger than the width of the solder-plated copper foils 5 and 5 ′.
If the thickness is 25 mm or more with respect to the solder-plated copper foil having a thickness of 25 mm, insulation can be ensured even if the solder-plated copper foil is shifted.
FIG. 7B shows a glass non-woven fabric sheet or 160 ° C.
1 shows a heat-resistant synthetic fiber nonwoven fabric sheet 7 and a filler 6 sandwiching the sheet.

The filler 6 is supplied as a thermoplastic sheet in the case of the above-mentioned EVA. In this case, the insulating sheet is processed into the same shape as the insulating sheet, and the insulating sheet is sandwiched like a sandwich and set at a predetermined position. These sheets are
It is also possible to temporarily fix EVA by partially melting it so as not to shift. The inventors have found that the temperature setting of the electric iron (with a Teflon surface on the surface) is set to “medium” (iron temperature 130 ° C.), and that there is no displacement by partially pressing the iron. When the temperature setting is set to “high”, the temperature becomes 160 ° C. or higher, and the EVA deteriorates, so care must be taken in the temperature setting.

The EVA 6 tends to shrink in the stretching direction due to heating, and in order to secure dimensional accuracy, a material made by a stretching method that does not easily shrink (for example, a biaxial stretching method) is used. Measure the heat shrinkage and set the direction that does not easily shrink to the longitudinal direction that requires dimensional accuracy, or
It is necessary to take measures such as using after stabilizing the dimensions by preliminary heating. The placement of the insulating sheet and the filler can be selected before or after the placement of the solder-plated copper foils 5, 5 'according to the embodiment. [Installation of backside protective cover] Solder-plated copper foils 5, 5 'up to the power extraction connection means are placed at the terminal box installation position.
The terminal box side end is bent so as to be perpendicular to the substrate, and as shown in FIG. 7 (C), a filler covering the entire surface of the substrate with a slit 10 through which a solder-plated copper foil is passed is covered. In the case of EVA, the use of a slightly larger size than the substrate can cope with the aforementioned heat shrinkage.
Generally, it is preferable to increase the length by 2% to 5%. Slit 10 for passing solder plated copper foil 5, 5 '
It is necessary to cover as much as possible because the portion other than the portion of the copper foil that goes out of the back cover needs to be covered with the filler.

The back protective cover 13 also needs to be provided with an opening 14 similarly.
When a cover including a metal layer such as a three-layer sheet of er / Al foil / Tedler is used, when the solder-plated copper foils 5, 5 'and the metal layer come into electrical contact at the opening 14,
Even when all of the output of the solar cell is short-circuited by the metal layer and no output is obtained, or when the copper foil of one pole and the metal layer are in contact with each other, a part of the back surface protective cover 13 is installed later. Contact with the equipment and mounting fixtures, causing electrical leakage and a safety problem. According to industrial standards, it is determined that the withstand voltage between the frame or the metal fitting and the terminal is maintained at 1.5 kV or more.

As a countermeasure for this, the back protective cover 1
3 is made larger than the solder-plated copper foil, is larger than the opening of the protective cover, and has a hole or slit through which the solder-plated copper foil is passed, and another glass nonwoven sheet embedded in the filler or a heat-resistant 160 ° C. A method is adopted in which the synthetic fiber nonwoven fabric sheet 11 is arranged on the filler and then the back surface protective cover 13 is provided.

More specifically, as shown in FIGS. 7 (D) and 8 (E), a nonwoven glass sheet or a sheet 160 having a cut slightly larger than the hole of the protective cover is formed on the filler sheet.
A heat-resistant synthetic fiber nonwoven fabric sheet piece 11 may be set around the solder-plated copper foil and a protective cover may be set.

As another embodiment of the present invention, a glass nonwoven fabric sheet or a 160 ° C heat resistant synthetic fiber nonwoven fabric having the same size as the filler 9 is used instead of the glass nonwoven fabric sheet or the small piece of synthetic fiber nonwoven fabric sheet 160 ° C heat resistant. It is also possible to use a sheet. In this case, there is a problem that the cost of the nonwoven fabric sheet increases, but the back surface protective cover 13 is Tedler / Al foil / Tedler.
In the case where metal is used inside like a three-layer sheet, when protrusions are generated on wiring members such as solder-plated copper foil or solder, these protrusions break through the resin layer such as Tedler etc. It is possible to prevent the problem of contact with the metal foil.

Also, a sheet in which EVA and a glass nonwoven fabric are laminated is sold. In this embodiment, it can be used particularly effectively, including insulation between the wirings 5 and 5 ′ and the element surface 2.

Further, the glass non-woven fabric does not undergo heat shrinkage, and has a stiffness as a material, so that it is easy to handle.

By removing the solder-plated copper foil from the opening of the protective cover and temporarily fixing it at a position where the copper foil and the protective cover do not come into contact with each other with a heat-resistant tape, it is possible to prevent a short-circuit without shifting during the vacuum laminating process. I can do it. See FIGS. 8F and 8G. [Vacuum Laminating Step] The solar cell module assembled in the above steps is heated and pressed by a double vacuum tank laminator (abbreviated as vacuum laminator) in which a vacuum chamber is vertically separated by a rubber diaphragm. The solar cell module is set in the device with the glass facing down.

First, the upper and lower vacuum chambers are evacuated at a temperature of about 100 ° C. to degas the solar cell module. The ultimate vacuum at this time is about 0.5 torr in the catalog of the apparatus. During this time, the EVA melts and bubbles and the like inside are removed. Next, the module is pressure-bonded at atmospheric pressure by introducing air into the upper vacuum chamber. As it is, the temperature is raised to about 150 ° C. to crosslink the EVA. This cross-linking time took about 15 minutes around 1980, but recently a fast cure product has been sold and can be cross-linked in about 2 minutes.

The thin-film solar cell module assembled as described above is completed as a product by removing the filler and the protective cover protruding around the substrate and attaching the peripheral frame and the terminal box to predetermined places.

FIG. 9 shows the configuration of the superposition of the sheets in the above steps.

In the portion other than the periphery of the wiring portion of the thin-film solar cell module, there are two layers of the filler and the cover as shown in FIG. 9A, whereas in the peripheral portion of the wiring, FIG. As shown, two filler layers 6, 9, one non-woven fabric layer 7,
There is a portion where the solder-plated copper foil 4 overlaps and is disposed inside the back protective cover, and the thickness of this portion is theoretically about twice as large as the thickness of the other portions. Since the filler is dispersed around the periphery, the increase in the thickness of this portion is extremely small.

As a method for further reducing the increase in thickness, if the thickness of the main filler is 0.4 mm, a 0.2 mm filler is used for a portion newly used in the present invention. preferable.

As described above, by using the structure and the manufacturing method of the present invention, the space between the back sealing cover and the glass substrate is filled with the components and the resin, and no thin film solar cell module is formed. Could be made easily. Further, according to the present invention, contact between the wiring and the back surface sealing cover could be prevented. In the above description, a specific material is used, but the same can be applied to other materials. In addition, the bus area is described as a pair, and the terminal box is provided in one place,
The present invention is not limited to this structure.
It is needless to say that a plurality of series-connected integrated solar cells exist on a single substrate as disclosed in 171675 and can be applied to a wiring for collecting them in one terminal box in parallel, and a favorable result is obtained. Absent.

[0059]

Next, an embodiment of the present invention will be described by using an amorphous silicon solar cell formed on glass as an EVA and a Tedle.
A specific application in which a three-layer film of r / Al foil / Tedler is used will be described in detail.

(Example 1) As the transparent insulating substrate 1, short sides 5
A blue plate glass having a length of 0 cm and a length of 100 cm and a thickness of 4 mm was used. This glass has a chamfered periphery of the cut surface to prevent thermal cracking and mechanical destruction during the process.

On the glass, SiO2 was formed as an alkali barrier at a thickness of 1000 .ANG.
Was formed by fluorine-doped SnO2 at 10000. The surface has irregularities formed by the apex angles of the crystal grains.

A groove 18 was formed in the transparent electrode layer 16 by laser processing using the second harmonic of a YAG laser.

Then, a semiconductor layer 19 of p-type amorphous silicon carbide was formed at 100.degree., I-type amorphous silicon at 3000.degree., And n-type amorphous silicon at 300.degree.

A groove 21 for connection to an adjacent photovoltaic element was provided using the second harmonic of the YAG laser.

Further, on the semiconductor layer 19, ZnO was formed at a thickness of 1000 ° and Ag was formed at a thickness of 3000 ° by a sputtering method to form a back electrode layer 22.

These back electrode layers 22 were formed with grooves 24 by using the second harmonic of a YAG laser, and individual electrodes 23 were obtained. With this configuration, the unit elements 28 each having a semiconductor sandwiched between the transparent electrode and the back electrode are connected in series. The width of this unit element is about 10 mm.

Similarly, bus regions 3 and 3 'for collecting electric power were provided at both ends of these elements with a width of 5 mm using laser processing. The distance between the positive electrode bus region 3 ′ and the negative electrode bus region 3 was 48 cm. A plurality of grooves 25 for exposing the transparent electrode layer are provided in this region, and 2 cm
Ceramic solder bumps 2 using ultrasonic soldering iron
6 were provided.

This bump has a width of 2 mm and a thickness of copper foil of 0.2 m.
m, a solder-plated copper foil 4 having a solder thickness of 0.1 mm was connected.

The peripheral region 27 of the substrate 1 was polished by a sand blast method to provide a region where all the upper layers did not exist.

The solder-plated copper foil 4 on the bus area
4 ′ was adjusted so as to form a gap of 0.1 mm so that the filler filled the gap between the copper foil and the element surface.

The solder-plated copper foils 4 on the bus areas 3, 3 '
4cm length 30cm width 5mm 5cm from the edge of the substrate
Are connected. The thickness of the copper foil and the thickness of the solder are the same as those of the above-mentioned solder-plated copper foil.

The connection between the solder-plated copper foils was made by superposing the two at the place to be connected and melting the solder on the copper foil with a soldering iron while holding down.

In order to insulate the 5 mm-width solder-plated copper foils 5, 5 'from the surface of the element, the length is 48 cm and the width is 2.5c.
EVA6 with a thickness of 0.4 mm and a thickness of 0.2 m, a thickness of 0.2 m
The glass non-woven fabric 7 having a thickness of 2 m was inserted into the gap. EVA6 used was white.

The 5 mm-wide solder-plated copper foils 5, 5 'were bent at intervals of 2 cm at the center of the short side of the solar cell so that the end on the terminal box side was perpendicular to the substrate. The temperature setting of the electric iron (with a Teflon surface on the surface) was set to “medium” from above the copper foil (iron temperature 130 ° C.) and partially pressed to temporarily fix the iron.

An EV having a width of 52 cm and a length of 104 cm having an 8 mm incision slit 10 opened thereat.
The A sheet 9 was set. From the slit 10, solder-plated copper foil from both electrodes was drawn.

A 1.5 cm square 6 mm
The glass nonwoven fabric sheet piece 11 having the notch was set in such a manner that the notch was passed through both solder-plated copper foils.

As a backside protective cover, a white Tedler / Al foil / Tedler three-layer structure film 13 having a 1 cm square hole 14 opened was solder-plated through the opening to protect the copper foil with the copper foil with a heat-resistant tape. Temporarily fixed to a position where the cover does not touch.

These were laminated by a double vacuum tank type laminator (abbreviation: vacuum laminator) to obtain a thin-film solar cell module of the present invention.

When 1500 V was applied for 1 minute between the terminal of this module and the Al layer of the back protective cover, it was found that insulation was achieved.

In order to subject the module to a high-temperature and high-humidity test, the module was left in an environment of 85 ° C. and 85% for 1000 hours, and the insulation between the terminal and the protective cover was measured. The power generation characteristics of the solar cell module were measured, but did not change at all before and after the high-temperature and high-humidity test.

Thereafter, an attempt was made to disassemble the module, but the filler was completely retained, and no water entered from the portion where the solder-plated copper foil was taken out.

[0082]

As described above, according to the present invention, it is extremely easy to significantly improve the reliability as compared with the conventional thin film solar cell module by using two nonwoven fabric sheets and one EVA additional member. It was realized by adding additional processes.

[Brief description of the drawings]

FIG. 1 is a laminated perspective view of each member of a thin-film solar cell module of the present invention.

FIG. 2 is a laminated perspective view of each member of a conventional thin-film solar cell module.

FIG. 3 is a laminated perspective view of each member of a thin-film solar cell module of a conventional improved example.

FIG. 4 shows a structure of a wiring portion of a conventional improved example.

FIG. 5 is a cross-sectional view of an example of a thin-film solar cell used in the present invention.

FIG. 6 is a top view of an example of a thin-film solar cell used in the present invention.

FIG. 7 is a process diagram (1) of the wiring of the present invention.

FIG. 8 is a process diagram (2) of the wiring of the present invention.

FIG. 9 is a sectional view of a wiring portion according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transparent insulating substrate 2 Solar cell power generation area 3, 3 'bus area 4, 4' Means for increasing the conductance of the bus area (solder plated copper foil) 5, 5 'Connection means for outputting power to the outside and the bus area Wiring (solder-plated copper foil) 6 Filler for burying insulating sheet 7 Glass nonwoven sheet or 180 ° C heat-resistant synthetic fiber nonwoven sheet 9 Filler 10 Opening provided in filler to pass 5 wiring 11 Back Non-woven glass sheet with opening to prevent contact between the opening of protective cover and wiring of 5 or 180 ° C
Small pieces of heat-resistant synthetic fiber non-woven fabric sheet 13 Back protective cover 14 Openings provided in the rear protective cover for passing the wiring of 5 15 Insulating material used in the conventional invention 16 Transparent electrode layer 17 Individual transparent electrode 18 Individual transparent electrode Groove 19 for forming semiconductor layer 20 Separately divided semiconductor layer 21 Groove provided in semiconductor layer for connecting adjacent photovoltaic elements 22 Back electrode layer 23 Individual back electrode 24 Separates back electrode Grooves for connecting conductance increasing means to the bus area 26 solder bumps 27 insulating areas provided around the thin-film solar cell 28 individual photovoltaic elements 44, 45 constituting the thin-film solar cell 44, 45 insulated solder Plated copper foil 100 solar cell element

Claims (8)

(57) [Claims] 1. A layer including a transparent electrode layer, a photovoltaic thin film semiconductor layer, and a back electrode layer is sequentially formed on a transparent insulating substrate,
A photovoltaic element divided into a plurality of regions is electrically connected, and a thin film solar cell having a bus region for collecting power as an end of the connection, and protecting a surface on which the thin film solar cell is formed In a thin-film solar cell module including a sealing unit including a filler and a back surface protective cover, and a connecting unit for supplying electric power generated by the thin-film solar cell to the outside, the wiring from the bus region to the connecting unit includes: A glass nonwoven fabric sheet or 160 embedded in the filler and between the wiring and the back electrode layer and embedded in another filler.
A thin-film solar cell module comprising a synthetic fiber non-woven fabric sheet having a heat resistance of ° C. 2. The glass nonwoven fabric sheet or 180
The thin-film solar cell module according to claim 1, wherein the synthetic fiber nonwoven sheet having a heat resistance of ℃ is of the same color tone as the protective cover. 3. The thin-film solar cell module according to claim 1, wherein the wiring is a copper wire or foil coated with solder or tin. 4. The glass nonwoven fabric sheet or 160
The filler for embedding the synthetic fiber non-woven fabric sheet that is heat resistant to ℃ is the same type of filler as the filler that seals the solar cell element surface, and its color tone is the same as that of the backside protective cover. The thin-film solar cell module according to claim 1, wherein 5. The thin-film solar cell module according to claim 1, wherein the filler is any one of ethylene / vinyl acetate copolymer (EVA), silicone, and polyvinyl butyral (PVB). 6. The means for increasing the electric conductivity of the wiring and bus regions is a solder-plated copper foil having a width of 2 mm or more, and a thickness of the solder plating is 50 μm or more, preferably 100 μm or more.
2. The thin-film solar cell module according to claim 1, wherein the thickness is 0 μm or less. 7. A layer including a transparent electrode layer, a photovoltaic thin film semiconductor layer, and a back electrode layer is sequentially formed on a transparent insulating substrate,
A step of forming a thin-film solar cell having a bus region in which photovoltaic elements divided into a plurality of regions are electrically connected and collecting power as an end of the connection, and the thin-film solar cell and the thin film thereof A step of forming a wiring connecting the connection means for supplying the electric power generated by the solar cell to the outside, and a filler, a glass nonwoven sheet or 160 ° C. in a region including a region where the wiring projects onto the thin-film solar cell. A step of sequentially laying a heat-resistant synthetic nonwoven fabric sheet between the thin-film solar cell and the wiring, and a step of laying a filler material that covers the entire surface of the thin-film solar cell and has a wiring hole for allowing the wiring to reach the connection means. And a step of laying a back protective cover having a hole at a position corresponding to the filler, covering the entire surface of the filler. . Wherein said filler is supplied with an ethylene-vinyl acetate copolymer used in the vacuum lamination method (EVA), polyvinyl butyral (PVB) uncured sheet such as, melted by heating, It is of the type that is thermally crosslinked, and it is necessary to lay a filler, wiring, glass non-woven fabric sheet or 160 ° C heat-resistant synthetic fiber non-woven fabric sheet, back protective cover in sheet form, fix it by vacuum laminating after assembling. The method for manufacturing a thin-film solar cell module according to claim 7 .