JP4023961B2 - Lamination method and laminating apparatus for solar cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminating method and a laminating apparatus for manufacturing a solar cell panel.
[0002]
[Prior art]
As a laminating apparatus for manufacturing a solar cell panel, there are those disclosed in Japanese Patent Laid-Open No. 9-14743 and Utility Model No. 3037201, etc., but a conventional general laminating apparatus expands downward. The upper chamber is formed by a flexible diaphragm, and a vacuum vessel body corresponding to the lid having a lower chamber having a heat generating plate, and its usage is as follows. That is, with the lid open, on the heat generating plate provided in the lower chamber of the main body, the lowermost layer is a glass plate, and a sheet-like filler, solar cell, and sheet-like filler are placed thereon. By laminating sequentially, placing the workpiece with the sheet-like back material on top, depressurizing the upper and lower chambers, heating the workpiece, and introducing the atmosphere into the upper chamber The workpiece is laminated by pressing between the upper surface of the heat generating plate and the diaphragm.
[0003]
In the above apparatus, the upper chamber and the lower chamber are depressurized, that is, evacuated, so that bubbles do not remain in the work piece. The reason is that the bubbles remain in the solar cell while remaining in the sunlight. This is because when the temperature is increased, bubbles are expanded and deterioration is accelerated.
[0004]
The workpiece is heated by the heating plate, but the temperature of the heating plate is controlled to the set temperature, and after a certain amount of time has elapsed, the workpiece becomes substantially the same as the temperature of the heating plate, so the set temperature is filled. By making the melting point higher than the melting point of the material, the filler is melted. By introducing the atmosphere only to the upper chamber, the diaphragm is expanded, and the workpiece is pressed against the heating plate and joined together. Therefore, after this joining, the lower chamber is returned to atmospheric pressure, the lid is opened, and the workpiece is taken out.
[0005]
On the other hand, EVA resin (ethylene vinyl acetate) or the like is used as the filler. However, when EVA resin is used, EVA resin melts at about 80 to 100 ° C. The EVA resin is melted at a temperature equal to or higher than 0 ° C. and press-bonded.
[0006]
However, in the above-described conventional laminating apparatus, for example, when manufacturing a relatively large size solar cell such as 1 m square, the lower surface of the workpiece in contact with the heating plate tends to rise in temperature, whereas the upper surface is Since the temperature is less likely to rise compared to the lower surface, a temperature difference occurs between the upper and lower surfaces. Due to this temperature difference, as illustrated in FIG. Occurs. Once warping occurs, the end portion of the warping is separated from the heat generating plate 11, so that the temperature is unlikely to rise. For this reason, in order to raise the temperature of the whole workpiece A to a uniform temperature, a long time is required, and there is a problem that productivity is deteriorated.
[0007]
Further, if the workpiece is pressed by the diaphragm by introducing the atmosphere into the upper chamber, the workpiece A that has been warped is pressed against the heat generating plate 11, so that the temperature at the end portion easily rises. If it does in this way, since it will press before EVA is not fully fuse | melted, there exists a possibility that the phenomenon that a photovoltaic cell may break may occur frequently. In FIG. 9, 7 is a vacuum container body, 12 is a lower chamber, and 13 is a sealing material for sealing a lid (not shown) applied to the container body 7 from above.
[0008]
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 ensure the strength. However, if the glass plate is increased, the temperature difference between the upper surface and the lower surface of the workpiece is increased. In addition, the glass plate may be broken.
[0009]
[Problems to be solved by the invention]
In view of the prior art as described above, the present invention has good productivity and reduces the occurrence of warpage of the workpiece by reducing the temperature difference between the upper surface and the lower surface of the workpiece. It is an object of the present invention to provide a laminating method suitable for manufacturing a large-sized solar cell and an apparatus therefor.
[0010]
[Means for Solving the Problems]
Structure of lamination method in the solar cell manufacturing of the present invention made for the purpose of solving the above problems, the interior of the laminating apparatus having upper and lower chambers, as well as heating elements partitioned by da diaphragm and a surface material, filled A solar battery composed of a material, a solar battery cell, a filler, and a back material is placed, the lower chamber is depressurized, the filler is heated by the heating element, and a gas is introduced into the upper chamber and pressed. in laminating a solar cell that, the press, and pressed at a low pressure, the filling material is characterized in the press child at a higher pressure after the molten.
[0011]
The present invention, in the configuration of the above methods, the heating to melt the filler, it is possible to row intends configuration from the outer surface member and back surface member of the solar cell. That is, the laminating method of the present invention performs laminating by heating from both the front and back surfaces of the workpiece constituted by the surface material, filler, solar battery cell, filler, and back material to melt the filler. In this way, warpage is eliminated and heat conduction is improved, so that productivity can be improved, and further, when a glass plate is used as a surface material, its internal stress can be reduced. Can prevent cracking.
[0012]
Further, 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 workpiece is set in the lower chamber, the lower chamber is evacuated, and a gas is supplied to the upper chamber. When pressing and introducing, first press at a low pressure and then press at a high pressure. This is because the solar cell is pressed against the heat generating plate without cracking, and the temperature of the work piece is reduced. The lamination is completed by pressing at a high pressure at a stage where the temperature is uniformly raised and accelerated.
[0013]
Next, the configuration of the laminating apparatus of the present invention for carrying out the laminating method described above is a laminating apparatus having an upper chamber and a lower chamber partitioned by a diaphragm, and has a heating plate with a heater built in the lower chamber, In addition to providing a heater in the upper chamber and a plurality of pressure setting devices, the setting device can set the press pressure in the upper chamber to a low pressure and a high pressure.
[0014]
The present invention may be configured such that in the configuration of the above apparatus, a heater for heating gas and a blower for circulating the heated gas are provided in the upper chamber. If it does in this way, the gas heated in the upper chamber will be forcedly circulated, heat can be transmitted to a diaphragm, and a workpiece can be heated.
[0015]
Further, the present invention may be configured such that a plurality of timers for setting the time for introducing the gas into the upper chamber are provided in the configuration of the apparatus. That is, when this laminating apparatus was used, gas was introduced until one timer worked, and a low pressure was pressed, held for an appropriate time, and then the gas was introduced again, and the other timer worked. At this point, the introduction of gas can be stopped and high pressure pressing can be performed.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments 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 carrying out the method of the present invention, FIG. 3 is a cross-sectional view taken along the line B-B in FIG. 2 is a cross-sectional view showing a state in which the lid of the laminating apparatus is closed and laminating is performed by the method of the present invention, FIG. 5 is a cross-sectional view of an example of the laminating apparatus of the present invention, and FIG. 6 is another example of the laminating apparatus of the present invention. 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 the workpiece when a workpiece is set | placed.
[0017]
In FIG. 1, A is a workpiece to be laminated, and a sheet-like filler 2, solar cells 3, and sheet-like filler 5 are sequentially laminated on the lowermost glass plate 1. The back material 6 is arranged on the back. Reference numeral 4 denotes a ribbon-like electrode for connecting the solar cells 3.
[0018]
In FIG. 2, 7 is a vacuum vessel body, 8 is its lid, 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, and 11 is a vacuum. A heating plate incorporating a heater attached to the container 7, 11 a is a support member for the heating plate 11, and 12 is a lower chamber formed between the inner upper surface of the vacuum container body 7 and the lower surface of the diaphragm 9. The lid 8 is sealed by a sealing material 13 provided on the opposite edge to be abutted. 7a is a gas pipe connection port of the vacuum vessel body 7, 8a is a gas pipe connection port of the lid 8, and both connection ports 7a and 8a are used for evacuation of the chamber and introduction of the atmosphere. The apparatus is configured as described above. In the laminating apparatus shown in FIG. 2, an upper heater 14 is disposed below the diaphragm 9 in order to carry out the method of the present invention. The upper heater 14 has flexibility formed by sandwiching a conductor between rubber sheets, and is attached to a sheet 15 having a characteristic of being flexibly bent and hardly stretched. The elastic sheet 16 is stretched and fixed to the inside of the lid 8.
[0019]
The arrangement of the upper heater 14 in the plane within the lid 8 is as shown in FIG. 3, and the upper heater 14 is configured by attaching a plurality of belt-like heating elements 14a, and the heating element 14a is disconnected or the like. If there is, only that part needs to be replaced, so that the loss can be reduced. In the example of FIG. 3, six heating elements 14a are attached. Therefore, as an example, if these are divided into three groups of two, it is easy to achieve uniform temperature control. The number of heating elements 14a of the upper heater 14 and the way of dividing the group are not limited to the above example. Further, as the sheet 15 for mounting the upper heater 14, for example, a silicon rubber sheet having a fiberglass sheet as a core material is used, while the stretchable elastic sheet 16 bonded to the sheet 15 is, for example, A silicone rubber sheet is used.
[0020]
Reference numerals 17 and 18 in FIG. 2 denote release sheets for preventing the melted fillers 2 and 4 from sticking out and adhering to the glass plate 1 or the like when the workpiece A is laminated. Similarly, 18 is disposed on the lower surface side of the workpiece A.
[0021]
Thus, as shown in FIG. 4, the workpiece A is placed on the heating plate 11, the lid 8 is applied to the vacuum vessel 7, the vacuum vessel 7 is evacuated, and the heating plate 11 and the upper heater. When the workpiece A is heated from above and below by 14 and the diaphragm 9 is pressed against the heat generating plate 11 from the upper surface to the lower surface of the workpiece A, the upper heater 14 is applied to the back plate 6 and the heat generating plate 11 is The glass plates 1 are pressed into contact with each other, and the fillers 2 and 5 are melted by heating them, and the workpiece A is defoamed to be formed into a laminate, and the lid is formed after the laminate is formed. 8 is removed and the workpiece A is taken out.
[0022]
In the above laminating process, the upper heater 14 is attached to a sheet 15 which is flexibly bent and hardly stretched, and the sheet 15 is joined to an elastic sheet 16 having stretchability attached in the lid 8 on both sides. The elastic sheet 16 expands in response to the pressing of the diaphragm 9, and compensates for the unextended portion of the sheet 15. Similarly, during the laminating process, even if the fillers 2 and 5 melted by heating protrude, the release sheets 17 and 18 receive it, so that the protruded fillers 2 and 5 adhere to the heating plate 11 and the sheet 15. There is no fear. In FIG. 4, 19 is a evacuation valve provided in a pipe connected to the connection port 8a, 20 is an air introduction valve, 21 is a pressure detector for detecting the press pressure, and 22 and 23 are pressure setting devices. It is assumed that a high pressure is set in one setting device 22 of these pressure setting devices, and a low pressure is set in the other setting device 23, respectively.
[0023]
In the example of the laminating apparatus of the present invention shown in FIG. 5, an upper heater 24 is installed on the back surface of the lid 8, that is, inside the upper chamber 10, and heat is transferred to the workpiece A through the diaphragm 9. The heat transfer from the upper heater 24 to the diaphragm 9 can uniformly heat the workpiece A by radiant heat transfer and heat transfer by the gas inside the chamber 10.
[0024]
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, the heated gas is forcedly circulated by the blower 26, and the temperature inside the upper chamber 10 is raised, thereby the diaphragm 9 is heated. The workpiece A is heated through the diaphragm 9 by heating. In this example, since the upper heater 24 is also installed in the chamber 10, it is possible to heat from the upper surface of the workpiece A by both heaters 24 and 25.
[0025]
The laminating apparatus shown in FIG. 7 has a timer for controlling the opening / closing operation of the control device 29 in order to control the opening time of the valve 20 for introducing the atmosphere into the upper chamber 10 in the laminating apparatus shown in FIG. It is provided with a plurality of times, the valve 20 is opened by the control device 29 for a set time of the timer 27, pressed at a low pressure, then the valve is closed, and after an appropriate time has elapsed, the valve 20 is opened again. After the time set to 28 elapses, the valve 20 is closed, so that pressing can be performed with high pressure, so that a suitable laminating process can be realized.
[0026]
FIG. 8 is a diagram showing an example of a laminating cycle in the laminating apparatus of FIG. 4, and the upper chamber 10 is evacuated similarly to the lower chamber 12 before pressing. From this state, the atmosphere introduction valve 20 is opened to introduce the atmosphere into the upper chamber 10. When the pressure setter 23 is activated, the pressure detector 21 closes the valve 20 so that pressing can be performed at a low pressure. In addition, it is desirable that this pressure is set to such an extent that the solar battery cell 4 is not broken. By being pressed at a low pressure, warping of the workpiece A is reduced, and heat transfer is improved by being pressed.
[0027]
After an appropriate time has passed since pressing at a low pressure, the solar battery cell, that is, the module, is constantly heated to a temperature at which the fillers 2 and 5 melt. Thereafter, until the pressure setter 22 is activated, the atmosphere is again introduced and pressed at a high pressure.
[0028]
The temperature control of the upper heater 14 and the heat generating plate 11 as the lower heater is controlled by the ratio of the time during which the current is energized and the time during which the current is not energized. When the target temperature is reached, the ratio of the time for energizing the heater to the time for not energizing becomes small. This is because it is sufficient to compensate for the amount of heat radiated from the heater and the amount of heat transferred to the workpiece A. In the present invention, the heat generating plate 11 and the upper heater 14 are controlled so as not to energize the other while energizing one of them. 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 need to be increased. As a result, the laminating apparatus of the present invention does not require a large power supply apparatus.
[0029]
The above description of the laminating cycle has been made by taking the laminating apparatus of FIG. 4 as an example, but it is needless to say that the laminating apparatus can be applied to the other laminating apparatuses described above.
[0030]
【The invention's effect】
The present invention is as described above, and in the laminate of solar cells, the workpiece is heated from both the upper and lower surfaces, so that the workpiece, particularly the solar cell, is heated compared to the heating from only the lower surface. Not only can warpage and cracking be suppressed, but also the time until the workpiece is heated to the required temperature can be shortened, and productivity can be improved.
[0031]
Also, when the workpiece is large, when heating it from the upper surface, the upper heater or diaphragm is brought into contact with the workpiece, but at this time, if suddenly pressed with high pressure, the cell tends to break, First, press the cell at a low pressure to prevent cracking of the cell, contact the workpiece with the upper heater or diaphragm, and when the filler melts, press the cell with high pressure and laminate it to crack the cell. It is possible to heat the workpiece from above while preventing this, and is therefore particularly suitable for improving the productivity of large workpieces.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a workpiece.
FIG. 2 is a sectional view showing a state in which a lid of an example of a laminating apparatus for carrying out the method of the present invention is opened.
FIG. 3 is a view taken along the line BB in FIG. 2;
4 is a cross-sectional view showing a state in which laminating is performed with the lid of the laminating apparatus of FIG. 2 closed.
FIG. 5 is a cross-sectional view of an example of the laminating apparatus of the present invention.
FIG. 6 is a cross-sectional view of another example of the laminating apparatus of the present invention.
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.
FIG. 9 is a cross-sectional view showing 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 seats
17 Upper release sheet
18 Lower release seat
19 Vacuum valve
20 Air introduction valve
21 Pressure detector
22, 23 Pressure setter
26 Blower C Piping
27, 28 timer
29 Control unit

Claims (5)

Inside the laminating apparatus having a partitioned upper and lower chambers and the heating element by da diaphragm and a surface material, filler, placed solar cell, filler, a solar cell composed of a backing material, said reducing the pressure in the lower chamber by heating the filler by the heating element, the lamination method of the solar cell to be pressed by introducing a gas into the upper chamber, the press, and pressed at a low pressure, after the filler is melted lamination method in the solar cell, wherein the pressing child at a higher pressure. Heating, lamination method in the surface member and the solar cell according to claim 1, intends row from the outside of the back sheet of the solar cell to melt the filler.   A laminating apparatus having an upper chamber and a lower chamber partitioned by a diaphragm, having a heating plate with a heater built in the lower chamber, a heater in the upper chamber, and a plurality of pressure setting devices, A laminating apparatus characterized in that the press pressure in the upper chamber can be set to a low pressure and a high pressure by a setting device.   The laminating apparatus according to claim 3, further comprising a heater for heating the gas and a blower for circulating the heated gas in the upper chamber.   The laminating apparatus according to claim 3 or 4, wherein a plurality of timers for setting a time for introducing the gas into the upper chamber are provided.

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