JP3121811B1 - 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. A wiring from a bus area is formed by a solder-plated copper foil, and insulation between an element surface and the solder-plated copper foil is performed by an insulating sheet embedded with a filler.

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, a wire drawn from the inside of the solar cell module is connected to the terminal, and an output power cable 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.

An alternative method is disclosed in Japanese Patent Laid-Open No. 9-326.
497 is easy to assemble, but when observing the completed module, the method shown in FIG. 2 reveals that there is no filler under the solder-plated copper foils 5, 5 ', and the opening shown in FIG. When the solder-plated copper foil was pulled from the gap, a gap was formed. In the structure of FIG. 3, the coated copper foil 45,
A gap similarly 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]

The inventor of the present invention has improved the means for satisfying the above conditions day and night with the structure disclosed in Japanese Patent Application Laid-Open No. 9-326497 as a starting point. Has found a simple and clear means to disclose.

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. There was an insulating sheet 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. Sandwiching a three-layer structure in which an insulating sheet is sandwiched between sheets of material, and in that region, a transparent insulating substrate, a thin-film solar cell element, a filler, an insulating sheet, a filler, a wiring (copper foil), a filler covering the entire surface, As a configuration in which a back cover covering the entire surface is 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, SiO ₂ 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.

[0022] As the transparent electrode layer 16, SnO ₂ is preferably used grown form unevenness is formed by the apex angle of the crystal grains. 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, the flux which is an acid-based material is unnecessary, and the problem of the flux remaining after sealing does not occur, which 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.

[Insulating Sheet] An insulating sheet 7 embedded in a filler is disposed between the wiring from the bus area to the connection means for supplying power to the outside and the element surface of the solar cell.

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 insulating sheet 7, it is preferable to use a material whose reliability has already been confirmed from the viewpoint of reliability. In order to secure insulation, it is better not to include metal.
A single sheet of an edler is a suitable choice, but other inexpensive resin films such as PET can be used if safety can be ensured.

Although the insulating sheet 7 can be made of a transparent material, the thin-film solar cell 100 has a portion 24 where no semiconductor or back electrode layer is present, and this portion is transparent when viewed from the light incident side. In order to hide the solder-plated copper foil, it is preferable to use the same color tone as the color of the back protective cover in contact with the filler.

The length and width of the insulating sheet 7 are appropriately selected so that the solar cell element group (power generation area 2) between the bus areas does not come into contact with the solder-plated copper foils 5, 5 '. The thickness is selected to be 30 μm to 100 μm so that the portion does not become a projection after sealing. Solder plated copper foil 5,
It is necessary to make the width of the insulating sheet 7 larger than the width of 5 ′.
If it is 5 mm or more, insulation can be ensured even if the solder-plated copper foil is shifted. FIG. 7B shows the insulating sheet 7 and the fillers 6 and 8 sandwiching the insulating sheet 7.

The fillers 6 and 8 in which the insulating sheet is embedded are 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 partially EVA
Can be melted and temporarily fixed. The inventors have found that the temperature setting of the electric iron (the surface of which has Teflon processing) is set to "medium" (iron surface temperature is 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.

The insulating sheets 7, EVA6, and EVA6 tend to shrink in the stretching direction due to heating, and are formed by a stretching method that does not easily shrink (for example, a biaxial stretching method) in order to secure dimensional accuracy. It is necessary to take measures such as using a heat-treated material, measuring the heat shrinkage in advance, and changing the direction in which shrinkage is difficult to the longitudinal direction requiring dimensional accuracy, or stabilizing the dimensions by preliminary heating before use. 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 Back Protective Cover] Solder-plated copper foils 5, 5 'to the power extraction connection means are bent at the terminal box installation position so that the terminal box side end is perpendicular to the substrate. Then, as shown in FIG. 7 (C), a filler is applied to cover the entire surface of the substrate having the slit 10 for passing the solder-plated copper foil. 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%. The slits 10 for passing the solder-plated copper foils 5 and 5 'need to be as thin as possible because they need to be covered with the filler except for the portion of the copper foil that goes out of the back cover.

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, a back protective cover 1
The opening 14 provided in 3 is larger than the solder-plated copper foil, and another insulating sheet 11 which is larger than the opening of the protective cover and has a hole or a slit through which the solder-plated copper foil passes and which is embedded in the filler is placed on the filler. And then installing the back protective cover 13.

Specifically, as shown in FIGS. 7 (D) and 8 (E), a small Tedler sheet piece slightly larger than the hole of the protective cover is cut on the filler sheet around the solder-plated copper foil. Set, and an EV of almost the same size
After the A sheet small piece 12 is set, the protection cover may be set.

By removing the solder-plated copper foil from the opening of the protective cover and temporarily fixing it with a heat-resistant tape at a position where the copper foil does not come into contact with the protective cover, it is possible to prevent short-circuiting 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 type 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 in this manner is completed as a product by removing the filler and the protective cover protruding from the periphery of 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.

The portion other than the periphery of the wiring portion of the thin-film solar cell module has two layers of a filler and a cover as shown in FIG. 9A, whereas the peripheral portion of the wiring has a structure shown in FIG. 9B. As shown, there is a portion in which the three filler layers 6, 8, 9, one insulating sheet layer 7, and the solder-plated copper foil 4 overlap and are disposed inside the back protective cover. It may look raised and cause stress concentration of the sealing material.

As a countermeasure, assuming that the thickness of the main filler is 0.4 mm, it is preferable to use a 0.2 mm filler for a portion newly used in the present invention.

Further, in order to solve the problems of the workability of the insulating portion and the above-mentioned appearance according to the present invention, it was invented to use a glass nonwoven fabric as the insulating sheet.

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, there is a type in which long fiber glass fibers are bound with more reliable acrylic or the like, and can be selected as appropriate.

When a glass non-woven fabric is used as the insulating film, a film thicker than the resin film is used in consideration of the fact that the glass non-woven fabric is pressed in the vacuum laminating step to reduce the volume. Preferably, one having a thickness of 0.1 to 0.4 mm is used.

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 30 and one filler sheet 31 is inserted. In the case of an insulating sheet made of a resin film, the sheet cannot be buried if there is no filler on both sides thereof. However, in the case of a glass non-woven fabric, one filler is sufficient because the filler penetrates into the gap of the non-woven fabric. Further, in insulating the opening of the back protective cover, it is not necessary to use a sheet of the filler only by installing one glass nonwoven fabric 32. This is because the glass nonwoven fabric penetrates the EVA of the filler sheet of the substrate size below it.

As described above, by reducing the number of filler sheets, not only the increase in the thickness around the wiring portion can be significantly suppressed, but also the operation becomes simple.
Furthermore, it has been found that the glass nonwoven fabric is very advantageous in terms of simplicity of the process of the present invention since the glass nonwoven fabric has a small heat shrinkage and has stiffness as a material, so that it is easy to handle.

FIG. 9 shows a configuration in the case of using a glass nonwoven fabric. It can be seen that the number of parts is significantly smaller than when no nonwoven fabric is used.

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 the thin film solar cell module has a structure in which no void 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.

[0062]

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 this glass, SiO 2 was formed as an alkali barrier at a thickness of 1000 ° by a thermal CVD method to form a transparent conductive layer 16.
Was formed by fluorine-doped SnO2 at 10000. The surface has irregularities formed by the apex angles of the crystal grains.

The grooves 18 were formed in the transparent electrode layer 16 by a laser processing method using the second harmonic of a YAG laser.

Then, a semiconductor layer 19 of p-type amorphous silicon carbide was formed at 100 °, i-type amorphous silicon at 3000 ° and n-type amorphous silicon at 300 ° by plasma CVD.

Using the second harmonic of the YAG laser, a groove 21 for connection with an adjacent photovoltaic element was provided.

Further, on the semiconductor layer 19, 1000 ° of ZnO and 3000 ° of Ag were formed by sputtering to form the back electrode layer 22.

These back electrode layers 22 were formed with grooves 24 using the second harmonic of a YAG laser to obtain individual electrodes 23. 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
The bumps 26 of the Cerasolzer were provided using an ultrasonic soldering iron.

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 places to be connected and melting the solder on the copper foils 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 m, 0.05 mm
Tedler7 of thickness, EVA8 of 0.4mm thickness 3
The layered product was inserted into the gap. Tedl
The color of er7 was white.

The 5 mm-wide solder-plated copper foils 5 and 5 ′ were bent at intervals of 2 cm at the center of the short side of the solar cell so that the terminal box side end was perpendicular to the substrate. It was set in an electric iron (with Teflon processing on the surface) from above the copper foil (iron surface temperature: 130 ° C) and partially pressed to temporarily fix it.

An EV with a width of 52 cm and a length of 104 cm having an 8 mm slit 10 opened in the corresponding place thereon
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
A small piece of Tedler sheet 11 having a notch is set in such a manner that a notch is passed through both solder-plated copper foils, and an EVA sheet piece 12 of the same size is set.

A white Tedler / Al foil / Tedler three-layer structure film 13 having a 1 cm square hole 14 as a backside protective cover is protected from the copper foil with a heat-resistant tape so that a solder-plated copper foil is exposed through the opening. Temporarily fixed to a position where the cover does not touch.

These were laminated with 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 completed.

In order to subject this 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.

After that, 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.

[0085]

As described above, according to the present invention, a significant improvement in reliability as compared with the conventional thin-film solar cell module is called insertion of a sheet-like insulating member and a filling sheet member. It was realized in a simple process.

[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.

FIG. 10 is a laminated perspective view of each member using a glass nonwoven fabric as an insulating sheet.

[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 6 (filler for embedding insulating sheet) 7 Insulating sheet 8 Filler for embedding wiring between insulating sheet and 5 9 Filling material 10 Opening provided in filling material for passing 5 wiring 11 Another insulating sheet with an opening for preventing the opening of the back protective cover from contacting with the wiring of 5 12 Filler for embedding the insulating sheet of 11 13 Back protective cover 14 Back protecting to pass the wiring of 5 Opening provided on cover 15 Insulating material used in conventional invention 16 Transparent electrode layer 17 Individual transparent electrode 18 Groove for individualizing transparent electrode 19 Semiconductor layer 20 Individually divided semiconductor layer 2 1 groove provided in the semiconductor layer for connecting adjacent photovoltaic elements 22 back electrode layer 23 individual back electrode 24 groove for separating back electrode 25 groove for connecting conductance increasing means to bus area Reference Signs List 26 solder bump 27 insulating region provided around thin-film solar cell 28 individual photovoltaic element constituting thin-film solar cell 30 insulating sheet made of glass nonwoven fabric 31 filler 32 separate insulating sheet made of glass nonwoven fabric 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 thin-film solar cell module, wherein an insulating sheet buried in the filler and between the wiring and the back electrode layer is buried in a filler of the same material as the filler for burying the wiring. 2. The thin-film solar cell module according to claim 1, wherein the insulating sheet is made of the same resin as a resin component of the protective cover, and has 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 thin-film solar cell module according to claim 1, wherein the filler for burying the wiring and the insulating sheet is the same type of filler. 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 electrical 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 a photovoltaic element divided into a plurality of regions is electrically connected and collecting power as an end of the connection; and A step of forming a wiring connecting the connection means for supplying the power generated by the solar cell to the outside, and a filler, an insulating sheet, and a filler in a region including a region where the wiring projects to the thin-film solar cell. A step of sequentially laying between the thin-film solar cell and the wiring; a step of laying a filler that covers the entire surface of the thin-film solar cell and has a perforated hole for allowing the wiring to reach the connection means; Laying a back protective cover having a hole at a position corresponding to the filler, which covers the surface of the thin film solar cell module. Wherein said filler is selected from the group consisting of ethylene-vinyl acetate copolymer used in the vacuum lamination method (EVA), it is supplied with polyvinyl butyral (PVB) uncured sheet such as, melted by heating, heat The thin-film solar cell according to claim 7, which is of a cross-linking type, in which a filler, a wiring, an insulating sheet, and a protective cover are laid in a sheet state, assembled, and fixed by a vacuum laminating method. Module manufacturing method.