JPH0992867A - Solar cell module manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a solar cell module superior in quality which uses a glass and is adaptable to a curved surface. SOLUTION: The manufacturing method comprises steps S1-S7 which vacuum heat a laminate composed of a cell matrix and packing sheets laid on both sides of the matrix to bond the sheets to the matrix, thereby forming a preformed sheet and steps S8 and S9 which heat this sheet laid on a curved glass plate to bond it to the glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solar cell module, and more particularly to a method for manufacturing a solar cell module having a curved shape.

[0002]

2. Description of the Related Art In a solar cell module, a transparent cover glass on the light-receiving surface side is used as a structural support, and a filling sheet (ethylene-vinyl acetate copolymer containing a cross-linking agent, hereinafter referred to as EVA) is provided on the inner surface of the cover glass. A matrix-shaped connected body (cell matrix) of solar cells is embedded via a filling sheet such as the above, and a protective sheet is joined to the outer surface thereof.

Various methods have been proposed in the past for manufacturing such a solar cell module.

For example, in Japanese Examined Patent Publication No. 6-52801, a laminated body of solar cells laminated between a flat cover glass and a back surface material is degassed by a double vacuum system, heated and pressed to bond them together. A manufacturing method is disclosed.

FIG. 4 shows the structure of a stacking device (laminator) for a solar cell module according to this double vacuum system. As shown in FIG. 4 (A), the inside of the vacuum chamber 17 is formed by the flexible diaphragm 16 (for example, a rubber film or the like may be used).
A chamber (upper chamber) 12 and a second chamber (lower chamber) 13 are divided into upper and lower halves, both chambers are connected to a true chamber pump (not shown), and a heating plate 14 is provided in the lower second chamber. It is a composition. The upper surface of the heating plate 14 is a flat mounting surface, on which the glass plate 30 is mounted, and the laminated body 15 of the solar cell module is mounted thereon. Then, first, both chambers are heated in a vacuum state, and then, as shown in FIG.
The chamber (upper chamber) 12 is brought to atmospheric pressure and the diaphragm 16 is moved to the second position.
The heating plate 1 in the second chamber is bent by bending to the chamber (lower chamber) 13 side.
The laminated body 15 on 4 is pressed against the glass plate 30 and further heated. Thereby, the filling sheet 3 in the laminated body 15
Is pressure-bonded, and this is pasted on a glass plate.
Conventionally, such a double vacuum type laminator has been used to form a solar cell module integrated with a glass plate.

On the other hand, in place of such a double vacuum type laminator, a method of manufacturing by bonding a solar cell module onto a glass plate using a vacuum bag in which a rubber bag or the like is connected to a vacuum pump is carried out. There is.

FIG. 5 shows the construction of a method for manufacturing a solar cell module using this vacuum bag. As shown, the glass plate 3
0, the laminated body 15 of the solar cell module is placed and inserted into the vacuum rubber bag 20, and the vacuum rubber bag 20 is placed in the heating chamber 18
Set inside. The heating chamber 18 is equipped with a heater 19 or other suitable heating means. Further, a vacuum pump 23 is connected to the heating chamber 18, and the vacuum rubber bag 20 in the tank can be evacuated via the coupler 22. The inside of the bag 20 is evacuated by the vacuum pump 23, and the rubber bag presses the laminate 15 against the glass plate 30. In this state, the inside of the heating chamber is heated so that the filling sheet 3 of the laminate 15 is pressure-bonded and bonded onto the glass plate 30. Thus, the solar cell module integrated with the glass plate was formed.

In recent years, as such a solar cell module, it has been desired to develop a module structure using curved glass in order to be mounted on a curved surface such as a roof surface of an automobile.

[0009]

However, in the method for manufacturing the solar cell module described in the above publication, since the heating plate of the double vacuum type laminator device is flat, the flat solar cell module is used when glass is used. However, there was a problem that it could not be applied to curved glass.

In this case, in order to apply it to curved glass, it can be dealt with by forming the surface shape of the heating plate in accordance with the curved shape of the glass, but it matches the curved surface of the module each time each module is manufactured. In addition, it is necessary to prepare a heating plate, which complicates the manufacturing process, lowers the productivity, and increases the cost, which is not practical.

Further, when the solar cell module is formed on the curved glass by the conventional method using a vacuum bag, when the filling sheet is pressure-bonded and the cells are sealed inside, air bubbles remain between the cells and the filling sheet. There is a problem that the reliability of the function is easily deteriorated, the cell matrix arrangement is easily disturbed, and the cells are easily moved to overlap with each other, resulting in a decrease in productivity and yield.

On the other hand, in order to deal with the problem when the solar cell module is arranged on such a curved surface, Japanese Patent Laid-Open No. 5-5
Japanese Patent No. 5617 proposes a method for manufacturing a flexible solar cell module that uses a fluorocarbon resin sheet instead of a cover glass and can be used for a curved surface. However, since the solar cell module using the fluororesin sheet disclosed in this publication uses a flexible resin material instead of the glass serving as the structural support, it has excellent light transmittance and excellent electrical insulation. There is a problem that the characteristics of the glass are not available. In addition, this solar cell module is to be used by attaching it to a curved surface.
The structure is not integrated with curved glass having rigidity as a structural support which is the basic structure of the present invention, and is not sufficient in terms of weather resistance and low moisture permeability, and the cell is protected against impact from the surface. There is a problem in that it cannot be done.

The present invention has been made in view of the above problems of the prior art, and provides a method of manufacturing a solar cell module having excellent productivity, which can be applied to a curved shape by using glass. With the goal.

[0014]

In order to achieve the above-mentioned object, in the present invention, a laminated body in which filler sheets are arranged on both sides of a cell matrix of a solar cell is vacuum-heated to bond each layer to form a preformed sheet. And a second step in which the preformed sheet is placed on a curved glass plate and the preformed sheet is bonded to the curved glass while heating in vacuum.
And a method for manufacturing a solar cell module.

In a preferred embodiment, the laminated body of the preformed sheets includes an embossed sheet having an uneven surface joined to the outside of one of the filling sheets of the both filling sheets, and the embossing sheet is subjected to the second step. It is characterized in that it is peeled off from the preformed sheet before. in this case,
It is preferable that the laminate of the preformed sheets includes a protective moisture-proof sheet on the outside of one filling sheet and an embossed sheet having an uneven surface on the outside of the other filling sheet.

Another preferred embodiment is characterized in that the embossed sheet is made of a material having a good releasability with respect to the filling sheet.

In still another preferred embodiment, the heat resistant temperature of the embossed sheet is equal to or higher than the crosslinking temperature of the filling sheet material.

In still another preferred embodiment, the embossed sheet is made of a sheet material having greater flexibility than the filling sheet.

In still another preferred embodiment, the emboss depth transferred to the filling sheet side by the emboss sheet is 10 to 20 μm in Ra and 50 to 1 in R _max .
The feature is that it is 00 μm.

In still another preferred embodiment, the embossed peaks transferred to the filling sheet side by the embossed sheet are 50 or more per 1 cm 2.

In still another preferred embodiment, the heating temperature in the first step is higher than the softening temperature of the filling sheet (hereinafter referred to as softening temperature) and lower than the crosslinking temperature.

In yet another preferred embodiment, in the second step, the preformed sheet together with the curved glass is inserted into a vacuum bag and heated to the crosslinking temperature of the filling sheet.

[0023]

In the first step, a flat preformed sheet is formed. This first step is performed using, for example, the above-mentioned double vacuum type laminator. Due to the vacuuming in the first step, the bubbles between the filling sheet and the cells are almost completely removed. At this time, the filling sheet is softened but is not crosslinked. Desirably, an embossed sheet having a mesh or an uneven surface is laminated on one surface of the preformed sheet to soften the filling sheet and join the embossed sheet.
By peeling off the embossed sheet, the uneven surface of the embossed sheet is transferred to the side of the preformed sheet. Place the preformed sheet on this curved glass with this embossed surface facing the curved glass side, insert it into a vacuum bag, heat it to the crosslinking temperature of the filled sheet in a vacuumed state, and press-bond the preformed sheet to the curved glass. To do. At this time, since a minute space due to embossing is formed between the preformed sheet and the curved glass, air bubbles are prevented from remaining due to the evacuation.
Further, in this case, since the bubbles around the cell have already been removed in the first step, the bubbles on the glass boundary surface can be sufficiently removed even under a gentle vacuum condition.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart showing, in order, each step of the method for manufacturing a solar cell module according to the embodiment of the present invention. 2 and 3 are cross-sectional views showing the module laminated structure in the manufacturing process in each step of the above flow.

First, in step S1, the layers of the solar cell module are stacked and mounted on the set base 1 made of flat glass. This laminated body, as shown in FIG.
First, the embossed sheet 2 having an uneven surface or a mesh shape is placed on the set table 1. The embossed sheet 2 is made of, for example, Teflon-coated glass cloth mesh, and its heat resistant temperature is higher than the softening temperature of a filling sheet (EVA) described later. The filling sheet 3a is placed on the embossed sheet 2, and the cell matrix 6 is placed thereon.

In this cell matrix 6, crystalline solar battery cells 4 formed on a semiconductor wafer are arranged in a matrix form (for example, 4 to 5 cell strings each consisting of 10 cells in one row or a similar number). Matrix)
, And the cells 4 are connected in series by a ribbon 5 made of, for example, a copper foil. The filling sheet 3b is placed on the cell matrix 6, and a protective sheet 7 made of a fluororesin or the like having a moisture-proof function is further laminated thereon.

Next, in step S2, the laminated body in which the respective layers are sequentially stacked in this manner is set together with the set table on the heating plate of the vacuum laminating apparatus (laminator). This laminator has the configuration shown in FIG.

Subsequently, the upper and lower chambers of the laminator are both evacuated and heated to a predetermined temperature (step S).
3). The vacuum conditions, heating temperature and heating time in this case are determined according to the size of the laminate, EVA and other materials and types of each layer. Then, the upper chamber of the laminator is leaked to atmospheric pressure, and the laminated body is heated while being pressed by the diaphragm (see FIG. 4) (step S4). The heating temperature at this time is equal to or higher than the temperature at which EVA softens, and
Below the crosslinking temperature. The vacuum condition at this time is about 5
The vacuum pressure is higher than torr. By performing vacuum heat treatment at such a temperature and under vacuum for a time period according to the specifications of the module to be manufactured, the EVA sheet is softened, and as shown in FIG.
Is embedded in the EVA 3 which is the filling sheet. At this time, since the treatment is performed in a relatively high vacuum state, bubbles between the cells and between the cells and the EVA sheet are sufficiently removed. In this way, the preformed sheet 9 is formed.

After this, this laminate (preformed sheet 9)
Is taken out from the laminator (step S5), and the embossed sheet 2 is peeled off after cooling (step S6). Then E
E embossed sheet 2 without significantly bending VA3
In order to smoothly peel off from the VA side, the embossed sheet is preferably made of a material having higher flexibility than EVA after softening and cooling below the crosslinking temperature and cooling. By peeling off the embossed sheet 2 in this manner, the unevenness of the embossed sheet is transferred to the EVA 3 side, and the embossed surface 8 is formed on the lower surface of the preformed sheet 9 as shown in FIG. The embossing depth of the embossing surface 8 is Ra of 10 to 10.
The emboss of the embossed sheet 2 is formed so as to be 20 μm and R _max of 50 to 100 μm. The embossing of the embossing sheet 2 is formed so that the embossing peaks on the embossing surface 8 are 50 or more per cm 2. After that, the trimming process adjusts the outer shape (step S7) to form a preformed sheet having a final shape.

Next, in step S8, as shown in FIG. 3D, the preformed sheet 9 is attached to the embossed surface 8 thereof.
Is placed on the curved glass 10 so as to face the curved glass 10. The radius of curvature of the surface of the curved glass 10 on which the preformed sheet is attached is about R3000. Thus, the preformed sheet is placed on the curved glass and inserted into the vacuum rubber bag shown in FIG.

Next, in step S9, the vacuum rubber bag is set in the heating chamber and heated while the inside of the rubber bag is evacuated by the vacuum pump. The vacuum condition at this time is about 30
The heat treatment is performed under a vacuum that is set to about torr and is milder than the vacuum conditions of the laminator described above. By this evacuation, when the embossed surface 8 is heated and pressure-bonded, the air on the joint surface is sucked and discharged to prevent bubbles from remaining. In this case, the bubbles around the cells have already been removed in the preformed sheet making process,
Even with a weak vacuum, the bubbles on the joint surface with the curved glass are sufficiently removed. The heating temperature at this time is the EVA crosslinking temperature. In this case, the heating time, the vacuum condition, the combination of the temperature and the vacuum condition, or the like may be appropriately controlled according to the module to be manufactured. As described above, by heating to a crosslinking temperature of EVA under a predetermined vacuum, EVA of the preformed sheet is completely solidified and integrally joined with the curved glass 10, and as shown in FIG. The module 11 is formed.

Subsequently, the cell terminal take-out portion is processed and resin sealing is performed to finish it as a product (step S1).
0). After this, a visual inspection and an electrical inspection are performed (step S11), and the process ends.

In the drawings described above, the scales and dimensions of the respective members are drawn differently from the actual ones in order to facilitate understanding of the drawings.

[0034]

As described above, in the present invention, in the first step, a preformed sheet having an embossed surface before being bonded to a curved glass is subjected to a vacuum heat treatment at a temperature lower than the crosslinking temperature of the filled sheet by using a laminator, for example. It is formed and bonded in a second step on a curved glass under a crosslinking temperature condition using, for example, a vacuum bag. Therefore, residual air bubbles around the cells and residual air bubbles on the glass bonding surface can be reliably prevented, and a high-quality solar cell module can be manufactured with high productivity and high yield. In this case, even if the vacuum condition is loosened in the second step, the bubbles on the glass bonding surface can be sufficiently removed, so that equipment of high vacuum system is not required and the cost can be reduced. Further, as a structure support having a curved shape, it is possible to use a glass that has excellent light transmission, excellent electrical insulation, low moisture permeability, high durability and weather resistance, and does not deteriorate in performance over a long period of time. Therefore, a curved solar cell module having sufficient strength and excellent characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a flowchart of a method for manufacturing a solar cell module according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a laminated state in each step of the preformed sheet manufacturing process according to the present invention.

FIG. 3 is an explanatory view showing a laminated state in each step of the curved glass pressure bonding step according to the present invention.

FIG. 4 is an explanatory diagram of a laminator used in the method of the present invention.

FIG. 5 is an explanatory view of a vacuum bag used in the method of the present invention.

[Explanation of symbols]

2: Embossed sheet, 3: Filling sheet, 4: Cell, 5:
Ribbon, 6: Cell matrix, 7: Protective sheet, 8:
Embossed surface, 9: preformed sheet, 10: curved glass,
11: Solar cell module.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hirohisa Suzuki 3-5 Kasumigaseki, Chiyoda-ku, Tokyo Kasumigaseki Building Showa Shell Sekiyu Co., Ltd. (72) Kenichi Tazawa 3-chome, Kasumigaseki, Chiyoda-ku, Tokyo No. 2-5 Kasumigaseki Building Showa Shell Sekiyu Co., Ltd.

Claims (9)

[Claims] 1. A first step of forming a preformed sheet by vacuum heating a laminated body in which filling sheets are arranged on both sides of a cell matrix of a solar cell to form a preformed sheet, and the preformed sheet is a curved glass plate. And a second step of bonding the preformed sheet to a curved glass while being placed on top and being heated in a vacuum, the manufacturing method of the solar cell module. 2. The laminated body of the preformed sheets includes an embossed sheet having an uneven surface joined to the outside of one of the filled sheets of the both filled sheets, and the embossed sheet is preliminarily prepared before the second step. It peels from a molded sheet, The manufacturing method of the solar cell module of Claim 1 characterized by the above-mentioned. 3. The method for manufacturing a solar cell module according to claim 2, wherein the embossed sheet is made of a material having a good mold release property with respect to the filling sheet. 4. The method for manufacturing a solar cell module according to claim 1, wherein the heat resistant temperature of the embossed sheet is equal to or higher than the crosslinking temperature of the filling sheet material. 5. The method for manufacturing a solar cell module according to claim 2, wherein the embossed sheet is made of a sheet material having a greater flexibility than the filling sheet. 6. The emboss depth transferred to the filling sheet side by the emboss sheet is Ra of 10 to 20 μm,
Method of manufacturing a solar cell module according to claim 2, wherein in R _max is 50 to 100 [mu] m. 7. The method of manufacturing a solar cell module according to claim 2, wherein the embossed peaks transferred to the filling sheet side by the embossed sheet are 50 or more per cm 2. 8. The method for manufacturing a solar cell module according to claim 1, wherein the heating temperature in the first step is equal to or higher than the softening temperature of the filling sheet and lower than the crosslinking temperature. 9. The solar cell module according to claim 1, wherein in the second step, a preformed sheet is inserted into a vacuum bag together with the curved glass and heated to a crosslinking temperature of the filling sheet. Manufacturing method.