JP2000101119A - Laminating method and device for solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a workpiece to be less warped so as to manufacture a large solar cell by a method wherein a solar cell is composed of a surface material, a filler material, a solar cell, a filler material, and a rear material, and the filler materials are melted by heating the solar cell from outside the surface material and the rear material. SOLUTION: A workpiece A subjected to laminate processing has a structure where a sheet-like filling material 2, a solar cell 3, and a sheet-like filler material 5 are successively laminated on a lowermost glass plate 1, and a rear material 6 is arranged on the top of the laminate. At this point, the workpiece A is placed on a heating plate, a vacuum chamber is covered with a lid and exhausted, the workpiece A is heated through both its upper and lower surface by a heating plate and an upper heater, and, when the workpiece A is pressed down with a diaphragm against the heating plate from above the upside of the workpiece A, the upper heater is pressed against the rear plate 6. The heating plate is pressed against the glass plate 1, whereby the filler materials 2 and 5 are melted by heating, and the workpiece A is degased into a laminate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminating method for manufacturing a solar cell panel and a laminating apparatus therefor.

[0002]

2. Description of the Related Art As a laminating apparatus for manufacturing a solar cell panel, there are those disclosed in Japanese Unexamined Patent Publication No. Hei 9-47443 and Japanese Utility Model No. 3032701. It is composed of a lid having an upper chamber formed by a diaphragm which can expand downward, and a vacuum vessel main body corresponding to the lid having a lower chamber having a heating plate. .
That is, with the lid open, a lowermost layer is a glass plate on which a sheet-like filler, a solar cell, and a sheet-like filler are placed on a heating plate provided in the lower chamber of the main body. By laminating sequentially, placing a workpiece with a sheet-like back material on the top, depressurizing the upper chamber and lower chamber, heating the workpiece, and introducing air to the upper chamber The workpiece is sandwiched between the upper surface of the heating plate and the diaphragm and laminated.

[0003] In the above apparatus, the reason why the upper chamber and the lower chamber are depressurized, that is, evacuated, is to prevent air bubbles from remaining in the workpiece, because the air bubbles are left in the solar cell. This is because, when exposed to sunlight and the temperature rises, the bubbles expand and deteriorate faster.

The workpiece is heated by the heating plate. The temperature of the heating plate is controlled to a set temperature, and after a suitable time, the workpiece becomes substantially the same as the temperature of the heating plate.
By setting the set temperature higher than the melting point of the filler, the filler is melted.By introducing air only to the upper chamber, the diaphragm expands, and the workpiece is heated to the heating plate. After the joining, the lower chamber is returned to the atmospheric pressure, the lid is opened, and the workpiece is taken out.

On the other hand, as a filler, EVA resin (ethylene vinyl acetate) or the like is used. However, when EVA resin is used, the EVA resin melts at about 80 to 100 ° C. 80 ~ 100 ℃
The EVA resin is melted at the above temperature and press-joined.

However, in the conventional laminating apparatus described above, when a relatively large solar cell such as 1 m square is manufactured, the temperature of the lower surface of the workpiece in contact with the heating plate tends to rise. Since the temperature of the upper surface is less likely to rise than that of the lower surface, a temperature difference occurs between the upper and lower surfaces, and the temperature difference causes the end of the workpiece A to be closer to the center as illustrated in FIG. A phenomenon of warping upward occurs. Then, once the warp occurs, the end of the warp is separated from the heat generating plate 11, so that the temperature does not easily rise.
Therefore, it takes a long time to raise the temperature of the entire workpiece A to a uniform temperature, and there is a problem that productivity is deteriorated.

Further, if the workpiece is pressed by the diaphragm by introducing the atmosphere into the upper chamber, the warped workpiece A is pressed against the heating plate 11, so that the temperature of the end portion also tends to rise. In this case, E
Since the pressing is performed before the VA is sufficiently melted, a phenomenon that the solar battery cell is cracked may frequently occur. In FIG. 9, reference numeral 7 denotes a vacuum vessel main body, 12 denotes a lower chamber, and 13 denotes a sealing material for sealing a lid (not shown) provided on the vessel main body 7 from above.

On the other hand, when the solar cell is formed in a larger size, it is necessary to increase the thickness of the lowermost glass plate in order to secure the strength. The temperature difference becomes more remarkable and the glass plate may crack.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has a high productivity and a small temperature difference between the upper surface and the lower surface of the workpiece. An object of the present invention is to provide a laminating method which is suitable for producing a large-sized solar cell, and an apparatus therefor, which reduces the occurrence of warpage.

[0010]

Means for Solving the Problems The structure of the laminating method in the production of a solar cell according to the present invention, which has been made to solve the above-mentioned problems, comprises a surface material, a filler, a solar cell, a filler, and a back material. In the manufacture of the solar cell configured, it is characterized in that the filler is melted by heating from the outside of the front surface material and the back surface material, and the configuration of a laminating apparatus that implements this method is configured by a diaphragm. What is claimed is: 1. A laminating apparatus having a partitioned upper chamber and a lower chamber, wherein the laminating apparatus has a hot plate having a built-in heater in the lower chamber, and has one or more flexible heaters disposed between the lower chamber and the diaphragm. It is characterized by having been provided.

That is, the laminating method of the present invention comprises a surface material,
Heating is performed from both the front and back surfaces of the workpiece composed of the filler, the solar cell, the filler, and the back material to melt the filler and laminate, thereby eliminating warpage and conducting heat. It is made to be good, and by doing so, it is possible to improve the productivity, and when using a glass plate as a surface material, the internal stress can be reduced,
Cracks can be prevented.

In the laminating method of the present invention, when laminating by a laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm, a work is set in the lower chamber, the lower chamber is evacuated, and the upper chamber is evacuated. When gas is introduced into the chamber and pressed,
First, press at a low pressure, and then press at a high pressure. This is done by pressing against the heating plate without causing cracks in the solar cells, making the temperature of the workpiece uniform, and at the stage where the temperature is raised uniformly, pressing by high pressure to laminate. Complete.

As a laminating apparatus for carrying out the above-described laminating method, a heating plate having a built-in heater is provided in a lower chamber, and one or more flexible heaters are provided between the lower chamber and the diaphragm. It is desirable to do it. This is because the heater is deformed along the workpiece when the workpiece is pressed.

Further, when a flexible heater is provided,
If a large number of flexible heaters are divided into a plurality of groups and the temperature is controlled for each group, it is possible to improve the temperature uniformity within the range to be pressed. Furthermore, by providing the plurality of flexible heaters individually and detachably, even if a failure such as disconnection occurs in the heater, only the portion can be replaced, and loss can be minimized.

In the above-described laminating apparatus, a heater constituted by sandwiching a conductor between rubber sheets is joined by a sheet which flexibly bends and does not easily expand, and an elastic sheet having extensibility is joined to the sheet. The sheet-like heating element may be provided between the lower chamber and the diaphragm. By bonding the heater to the sheet that is flexibly bent and hardly stretches in this way, even if the heater is deformed along the workpiece when pressed, the sheet prevents the heater from expanding, and the The life before disconnection can be lengthened. However, as it is, even if it can follow the workpiece, if the length is insufficient, it will not be able to adhere to the workpiece by that much, but this is due to the elastic sheet having stretchability at both ends of the sheet. Can be solved by joining. In addition, as a sheet that bends flexibly and does not easily expand, a rubber sheet or the like using glass fiber as a core material may be mentioned, and as an elastic sheet having stretchability, there is a silicon rubber sheet or the like.

Thus, a heating plate having a built-in heater in the lower chamber, and a heating plate disposed between the lower chamber and the diaphragm.
In the above-described flexible heater, when one of the heaters is energized, the other is not energized and the temperature is controlled. By doing so, even though heating is performed from both the lower surface and the upper surface, the maximum current to be supplied does not need to be large, so that a large power supply facility is not required.

A laminating apparatus for carrying out the laminating method of the present invention has a configuration in which a heating plate having a built-in heater is provided in a lower chamber, and a heater is provided in an upper chamber. In this apparatus, heat is transmitted to a diaphragm by radiant heat transfer and gas heat transfer from a heater inside an upper chamber, and a workpiece is heated via the diaphragm.

In the laminating apparatus for carrying out the laminating method of the present invention, a heating plate having a built-in heater is provided in the lower chamber, and a heater for heating gas and a blower for circulating the heated gas are provided in the upper chamber. Some have a configuration. In this case, the gas heated in the upper chamber is forcibly circulated, and heat is transmitted to the diaphragm to heat the workpiece.

Using a laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm, the lower chamber is evacuated, a gas is introduced into the upper chamber, and then pressed at a low pressure, and then pressed at a high pressure. A plurality of pressure setting devices may be provided as a laminating apparatus for performing the laminating method by performing the laminating method, so that the pressure in the upper chamber can be changed. According to this laminating apparatus, for example, a low pressure is set in one pressure setting device, a high pressure is set in the other pressure setting device, and when pressing at a low pressure, the low pressure is set. The gas is introduced into the upper chamber until the pressure setter operates, and when the pressure setter with the low pressure set operates, the introduction of the gas is stopped and maintained. Thereafter, in order to press at a high pressure, the gas can be re-introduced into the upper chamber, and the gas introduction can be stopped and maintained when the setter at which the high pressure is set is activated. If the stopping and holding of the introduction of the gas is continued for a relatively long time, the gas in the upper chamber may expand due to heat and the internal pressure may increase. In this case, when it is detected that the internal pressure has increased due to the set pressure, as an example, by instantly opening the vacuum evacuation valve and returning to the set pressure,
It is possible to keep the pressure constant.

Using a laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm, the lower chamber is evacuated, a gas is introduced into the upper chamber, and then pressed at a low pressure, and then pressed at a high pressure. As a laminating apparatus for performing the laminating method by performing the above, a plurality of timers for setting the time for introducing the gas into the upper chamber may be provided. That is,
When using this laminating apparatus, gas is introduced until one of the timers operates, a low-pressure press is performed, and after holding for an appropriate time, gas is introduced again, and when the other timer operates, Then, the introduction of gas can be stopped and a high pressure press can be performed.

[0021]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a cross-sectional view of a workpiece, FIG. 2 is a cross-sectional view of an example of a laminating apparatus for performing the method of the present invention with a lid opened, FIG. 3 is a view taken along the line BB of FIG. 2, and FIG. FIG.
FIG. 5 is a cross-sectional view showing a state where the lid of the laminating apparatus is closed and laminating by the method of the present invention is performed, FIG. 5 is a cross-sectional view of an example of the laminating apparatus of the present invention, and FIG. FIG. 7 is a cross-sectional view of another example of a laminating apparatus for carrying out the method of the present invention, FIG. 8 is a diagram showing a laminating cycle of the laminating apparatus of the present invention, and FIG. It is sectional drawing which shows the curvature of a to-be-processed object at the time of putting an object.

In FIG. 1, A is a workpiece to be laminated, and a sheet-like filler 2, a solar cell 3, and a sheet-like filler 5 are sequentially laminated on a lowermost glass plate 1. , The back material 6 is arranged at the top. Reference numeral 4 denotes a ribbon-shaped electrode for connecting the solar cells 3.

In FIG. 2, 7 is a vacuum vessel main body, 8 is a lid thereof, 9 is a diaphragm attached to the inside of the lid 8, 10 is an upper chamber formed between the inner lower surface of the lid 8 and the upper surface of the diaphragm 9, Reference numeral 11 denotes a heating plate having a built-in heater attached to the vacuum container 7, reference numeral 11a denotes a supporting member for the heating plate 11, and reference numeral 12 denotes a lower chamber formed between the inner upper surface of the vacuum container main body 7 and the lower surface of the diaphragm 9. The main body 7 and the lid 8 are hermetically sealed by a seal material 13 provided on the opposed edge to be brought into contact. 7a is a gas pipe connection port of the vacuum vessel main body 7, 8a is a gas pipe connection port of the lid 8, and both connection ports 7a and 8a are for evacuating the chamber and introducing the atmosphere. The device is configured as described above. In the laminating apparatus shown in FIG. 2, an upper heater 14 is provided below the diaphragm 9 in order to carry out the method of the present invention. The upper heater 14 has flexibility in which a conductor is sandwiched between rubber sheets, and is attached to a sheet 15 having a characteristic that it is flexibly bent and hardly expands. It is joined to a stretchable elastic sheet 16 fixed inside the lid 8.

The arrangement of the upper heater 14 in a plane within the lid 8 is as shown in FIG. 3, and the upper heater 14 is constituted by attaching a plurality of strip-shaped heating elements 14a.
If there is a disconnection or the like in 4a, only that part needs to be replaced, and the loss can be reduced. In the example of FIG.
Since 14a has 6 types attached, as an example,
If these are divided into three groups of two and temperature control is performed, uniform temperature control can be easily achieved. The upper heater 14
The number of heating elements 14a and how to divide the groups are not limited to the above example. Further, as the sheet 15 to which the upper heater 14 is attached, for example, a silicon rubber sheet using a fiber glass sheet as a core material is used, while, as the stretchable elastic sheet 16 to be joined to the sheet 15, for example, A silicone rubber sheet is used.

In FIG. 2, reference numerals 17 and 18 denote release sheets for preventing the molten fillers 2 and 4 from sticking out and adhering to the glass plate 1 or the like at the time of laminating the workpiece A. The reference numeral 18 is provided on the lower surface side of the workpiece A, and the reference numeral 18 is provided on the upper surface side of the workpiece A.

As shown in FIG. 4, the workpiece A is placed on the heating plate 11, the lid 8 is placed on the vacuum container 7, the vacuum container 7 is evacuated, and the heating plate 11 is evacuated. And upper heater 14
The workpiece A is heated from above and below by the
Is pressed against the heating plate 11 from the upper surface to the lower surface of the workpiece A, the upper heater 14 is pressed against the back plate 6 and the heating plate 11 is pressed against the glass plate 1. 5 is melted and the workpiece A is defoamed and formed into a laminate. After the laminate is formed, the lid 8 is removed and the workpiece A is taken out.

In the above laminating process, the upper heater
14 is attached to a flexible bendable and hardly stretchable sheet 15, and the sheet 15 is joined on both sides to an extensible elastic sheet 16 attached to the lid 8, so that the sheet 15 can be pressed by the diaphragm 9. The elastic sheet 16 expands, and compensates for the non-elongation of the sheet 15. Also, at the time of laminating, the filler 2 melted by heating,
Even if 5 protrudes, the release sheets 17 and 18 receive it.
There is no risk of sticking to 15 etc. Also, in FIG.
19 is a vacuum valve provided in the pipe connected to the connection port 8a, 20 is a valve for introducing air, 21 is a pressure detector for detecting press pressure, and 22 and 23 are pressure setting devices. It is assumed that one setter 22 is set to a high pressure and the other setter 23 is set to a low pressure.

An example of the laminating apparatus of the present invention shown in FIG.
The heat is transferred from the upper heater 24 to the diaphragm 9 by radiant heat transfer and heat transfer by the gas inside the chamber 10 by installing the heat transfer member 24 to the work A through the diaphragm 9. The workpiece A can be heated uniformly.

Another example of the laminating apparatus of the present invention shown in FIG. 6 is obtained by adding the following mechanism to the laminating apparatus shown in FIG. That is, the upper heater 25 and the blower 26 are provided outside the upper chamber 10 and outside the lid 8, and the blower 26 is connected to the inside of the upper chamber 10 by the pipe C. After pressing, the gas inside the upper chamber 10 is heated by the upper heater 25, and the heated gas is forcibly circulated by the blower 26 to raise the temperature of the gas inside the upper chamber 10, thereby causing the diaphragm 9 to be heated. The workpiece A is heated through the diaphragm 9. In this example, since the upper heater 24 is also installed in the chamber 10,
The workpiece A can be heated from above by the heaters 24 and 25.

The laminating apparatus shown in FIG. 7 is different from the laminating apparatus shown in FIG. 2 in that a control unit 29 controls the opening time of the valve 20 for introducing the atmosphere into the upper chamber 10.
A plurality of timers for controlling the opening and closing operations of the valve are provided.
The valve is closed by pressing at a low pressure and then closing the valve, and after an appropriate time has elapsed, the valve 20 is opened again.After the time set in the timer 28 has elapsed, the valve 20 is closed. Since the pressing can be performed under pressure, a suitable laminating process can be realized.

FIG. 8 is a diagram showing an example of a laminating cycle in the laminating apparatus shown in FIG. 4, in which the upper chamber 10 is evacuated similarly to the lower chamber 12 before pressing. From this state, the air introduction valve 20 is opened to introduce air into the upper chamber 10. When the pressure setter 23 operates, the pressure detector 21 closes the valve 20 so that pressing can be performed at a low pressure. It is desirable that this pressure is set to such an extent that the solar cell 4 is not broken. Pressing at a low pressure reduces the warpage of the workpiece A, and improves the heat transfer by being pressed.

After an appropriate time has elapsed after pressing at a low pressure, the solar cell, that is, the module, is constantly heated to a temperature at which the fillers 2 and 5 melt. After this,
Until the pressure setting device 22 operates, the atmosphere is introduced again and pressing is performed at a high pressure.

The temperature control of the upper heater 14 and the heating plate 11 serving as the lower heater is controlled by the ratio of the time during which the current is supplied to the time during which the current is not supplied. When the target temperature is reached, the ratio of the time during which power is supplied to the heater to the time during which power is not supplied becomes small. This is because the amount of heat dissipated from the heater and the amount of heat transferred to the workpiece A need only be compensated for. In the present invention, the heating plate 11 and the upper heater 14 are controlled such that while one of them is energized, the other is not energized. By doing so, the heaters 11 and 14 are not energized at the same time, so that the maximum current used in the apparatus does not increase, and as a result, the laminating apparatus of the present invention does not require a large power supply.

Although the above description of the laminating cycle has been made with reference to the laminating apparatus shown in FIG. 4, it goes without saying that the present invention can be applied to the other laminating apparatuses described above.

[0035]

The present invention is as described above, and in the solar cell lamination, the workpiece is heated from both the upper and lower surfaces. In particular, it is possible not only to suppress the occurrence of warpage or cracks in the solar battery cells, but also to shorten the time until the workpiece is heated to a required temperature, thereby improving productivity.

When the workpiece is large, the upper heater or the diaphragm is brought into contact with the workpiece when the workpiece is heated from the upper surface. Since it is easy to press at first with low pressure to prevent cracking of the cell, contact the upper heater or diaphragm with the workpiece, and when the filler melts, press and laminate with high pressure, The work piece can be heated from above while preventing the cell from cracking, and is therefore particularly suitable for improving the productivity of a large work piece.

[Brief description of the drawings]

FIG. 1 is a sectional view of a workpiece.

FIG. 2 is a cross-sectional view of an example of a laminating apparatus for carrying out the method of the present invention in a state where a lid is opened.

FIG. 3 is a view taken along line BB of FIG. 2;

FIG. 4 is a cross-sectional view showing a state where the lid of the laminating apparatus of FIG. 2 is closed and laminating is performed.

FIG. 5 is a sectional view of an example of the laminating apparatus of the present invention.

FIG. 6 is a sectional view of another example of the laminating apparatus of the present invention.

FIG. 7 is a sectional view of another example of a laminating apparatus for carrying out the method of the present invention.

FIG. 8 is a diagram showing a laminating cycle of the laminating apparatus of the present invention.

FIG. 9 is a cross-sectional view illustrating warpage of a workpiece when the workpiece is placed on a heating plate in a conventional laminating apparatus.

[Explanation of symbols]

 A Workpiece 1 Glass plate 2, 5 Filler 3 Solar cell 4 Electrode (ribbon) 6 Back plate 7 Vacuum container body 8 Vacuum container lid 9 Diaphragm 10 Upper chamber 11 Heating plate 12 Lower chamber 13 Sealing material 14, 24 , 25 Upper heater 14a Heating element 15, 16 Seat 17 Upper release seat 18 Lower release seat 19 Vacuum evacuation valve 20 Air introduction valve 21 Pressure detector 22, 23 Pressure setting device 26 Blower C piping 27, 28 Timer 29 Control apparatus

Claims (6)

[Claims] 1. A method for laminating a solar cell comprising a surface material, a filler, a solar cell, a filler, and a back material, wherein the heating is performed from outside the front material and the back material to melt the filler and laminate. A laminating method for a solar cell. 2. A method for laminating a solar cell comprising a surface material, a filler, a solar cell, a filler and a back material, wherein a laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm is used. A laminating method in a solar cell, wherein the chamber is evacuated, a gas is introduced into the upper chamber, and pressing is performed at a low pressure, followed by laminating by pressing at a high pressure. 3. A laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm, wherein the laminating apparatus has a heating plate having a built-in heater in the lower chamber, and a heater is provided in the upper chamber. Laminating equipment. 4. A laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm, wherein the laminating apparatus has a heating plate having a built-in heater in the lower chamber, and a heater for heating gas in the upper chamber. A laminating apparatus comprising a blower for circulating gas. 5. A laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm, wherein a plurality of pressure setting devices are provided to make the pressure in the upper chamber variable. 6. A laminating apparatus having an upper chamber and a lower chamber separated by a diaphragm, wherein a plurality of timers for setting a time for introducing gas into the upper chamber are provided.