JP2000307143A - Solar cell module and solar cell panel provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with an alignment operation where a glass and a solar cell are precisely aligned with each other and to remarkably simplify the assembly operation, by a method wherein connection members which electrically connect solar cells together to form an electric circuit and a sheet of cover which covers the connection members are provided. SOLUTION: A solar cell module 19 is equipped with a board 15, solar cells 13 which are arranged in a two-dimensional manner and bonded to the board 15 with adhesive agent 14, connection members or interconnectors 16 which electrically connect the solar cells 13, and a cover glass (glass) 11 which covers the solar cells 13 and the interconnectors 16. The cover glass 11 is bonded to the solar cells 13 and the interconnectors 16 with adhesive agent 12. The solar cell module 19 has a structure where the solar cells 13 is covered with a single sheet of the glass 11, where the solar cells 13 are housed in the glass cover 11, so that the solar cells 13 are not required to be precisely aligned with the glass cover 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell module provided with a plurality of cells having glass adhered to a surface, and a solar cell panel using the same.

[0002]

2. Description of the Related Art FIG.
As shown in FIG. 5, a conventional solar cell module for space 9
A glass (cover glass) 1 is bonded to each of a plurality of solar cells 3 with an adhesive 2, the cells 3 are connected in series and in parallel with a connecting member (interconnector) 6, and a substrate (sub- Straight 5). Therefore, the bus bar 8 provided at the end of the interconnector 6 and the module 9 is exposed and exposed to the space environment (for example, see Japanese Unexamined Patent Application Publication No.
No. 136441).

The universe is also an electromagnetic environment, and ionized electrons and ions exist in a plasma state. Therefore, the interconnector 6 of the solar cell module 9 in space
When the solar cell module 9 is exposed,
Since the electric power is discharged through the interconnector 6 and the generated power may be reduced and the solar cell 3 may be destroyed, measures have been taken to cover the interconnector 6 itself with an insulating resin (for example, see Japanese Unexamined Patent Publication No. 61-1986). No. 202474).

Further, in the conventional module, as shown in FIG. 16, when the glass 1 is bonded to the solar battery cell 3, the adhesive 2 protrudes from the side surface portion. The extruded adhesive 2 is exposed to the space environment and its light transmittance is reduced.
Since the output of the solar cell 3 on the lower surface is reduced, it is necessary to remove it. In addition, the solar cell 3 and the glass 1 are usually removed from 50 μm to 200 μm.
Since it was thin and easily cracked, it was also a cause of failure.

Further, in the conventional module, since the glass 1 is bonded to the individual solar cells 3, much work is required for the bonding operation. Further, a portion where the solar cell 3 is not covered with the glass plate 1 is rapidly deteriorated in a space environment, particularly by a low energy proton beam. On the other hand, when the size of the glass 1 is larger than that of the solar cell 3, the area ratio of the solar cell 3 to the total area of the module is reduced, and the output per area of the solar cell panel is reduced.

For this reason, the glass 1 cannot be made larger than the solar cell 3, and a high dimensional accuracy is required when bonding the glass 1 so that the solar cell 3 does not protrude from the glass 1. Making the work more time-consuming. Unless the alignment accuracy between the solar cells 3 and the glass 1 is increased, the distance between adjacent solar cells will increase as a result, and the area efficiency will decrease.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided an electric device comprising: a substrate; a plurality of solar cells arranged in a plane on the substrate; and an electrical connection between the plurality of solar cells. An object of the present invention is to provide a solar cell module including a connection member that forms a circuit, and one transparent cover plate that covers the plurality of solar cells and the connection member.

According to the present invention, since one transparent cover plate covers a plurality of solar cells, detailed positioning of the solar cells is not required except for the outer peripheral portion. There is no overhang. Further, since the electrical connection members between the solar cells are also covered with the transparent cover plate, adverse effects from the electromagnetic environment of the universe are suppressed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The substrate according to the present invention is preferably a substrate having a certain degree of flexibility in consideration of being mounted on a panel having a curvature. 0.2mm polyimide film or F
An RP film is used. In addition, solar cells
A conventionally known one, for example, a so-called silicon solar cell (50 to 200 μm in thickness) formed by diffusing a P-type impurity into an N-type silicon surface can be used.

[0010] A connection member for electrically connecting solar cells is generally referred to in the art as an interconnector for making a connection between solar cells, or a bus bar for outputting an output current from a solar cell module. Is taken out. The interconnector has a structure to absorb external stress,
It is preferable to have a so-called stress relief structure. The busbar material is silver or gold-plated silver,
Examples include silver-plated Kovar, molybdenum, aluminum, and copper.

The transparent cover plate is usually called a cover glass. However, considering its use environment, it is not colored even when exposed to cosmic radiation or the like, and has a wavelength suitable for the wavelength sensitivity characteristic of the solar cell, for example, 0.1 mm. It is preferable that the material is made of a material that efficiently transmits a wavelength of 35 to 1.2 μm, protects the solar cell from cosmic radiation, and has excellent mechanical strength and heat resistance. To do so, for example, a thickness of 50-200μ
Inorganic glass of about m is used, and cerium-added glass is particularly preferable because it is less colored by exposure to cosmic rays or the like.

In the solar cell module according to the present invention, an electric circuit is formed by connecting a plurality of solar cells in series and / or in parallel with a connecting member. When a module or cell cannot receive sunlight due to some external factor, a bypass diode or a switching element should be connected in parallel as a protection element to the electric circuit so that the electric circuit bypasses the electric circuit. Is preferred.

The protection element may be connected in parallel to each of the solar cells. However, this requires a large number of elements, so it is desirable to connect one element for each module.

Further, a solar cell module according to the present invention comprises:
A plurality of solar cells are connected to form a solar panel. Since the output of the solar panel is normally connected to a load and a battery, a reverse voltage applied from the battery is prevented when the solar cell module cannot receive sunlight. It is preferable to connect a reverse voltage blocking diode, that is, a blocking diode, in series as a protection element for this purpose.

The protection elements such as the bypass diode and the blocking diode are provided between the substrate and the transparent cover plate. In that case, a notch may be provided in a part of the solar battery cell, and a bypass diode or a blocking diode may be accommodated in the space of the notch.

When a space exists between adjacent solar cells, these diodes may be accommodated in the space. At this time, it is preferable that the bypass diode and the blocking diode have a shape (for example, a triangle or a trapezoidal cross section) corresponding to the space in which the bypass diode and the blocking diode are housed.

[0017] The solar cell module may further include a connection terminal for connecting an output of the electric circuit to the outside. In order to secure a storage space for the connection terminal, a cutout may be provided in the solar cell.

When connecting the solar cell modules using the connection terminals, a portion of the transparent cover plate corresponding to the connection terminal portion is cut out in advance, and after the connection, the cutout portion of the transparent cover plate is replaced with a glass plate. Alternatively, the connection terminal may be covered with a ceramic plate so as to shield the connection terminal from radiation or electric field environment in outer space.

In one solar cell module, a plurality of independent electric circuits may be formed. In that case, it is preferable that a bypass diode be connected in parallel for each electric circuit. Further, one power generation circuit may be formed by connecting a plurality of solar cell modules.

The solar cell and the transparent cover plate are adhered by a resin, and the resin is preferably a silicone resin with little outgas. In this case, since the physical properties of the silicone resin change rapidly at a low temperature (about -100 ° C.), it is preferable to provide an isolation member for dividing the resin layer in order to reduce the stress generated at that time. The transparent cover plate may be provided with a projection for positioning the solar cell.

In order to reduce expansion and contraction due to a difference in thermal expansion coefficient between the solar cell and the transparent cover plate, it is preferable to sandwich a member having a higher thermal expansion coefficient than the solar cell between adjacent solar cells. This member is preferably lower in rigidity than the solar cell in order to further reduce the mechanical stress.

A member may be provided on the substrate, the tip of which abuts on the transparent cover plate passing between adjacent solar cells, and the tip is formed so as to reflect sunlight and enter the solar cells.

As for the transparent cover plate, a plurality of glasses having the same size as the solar battery cells may be bonded with a material having a smaller coefficient of thermal expansion than that of the glass to form a single transparent cover plate. The transparent cover plate will break between adjacent solar cells when subjected to mechanical or thermal stress,
It is preferable that a scratch or a slit is formed in advance.

The present invention also includes a plurality of solar cells electrically connected to each other and arranged in a plane, and a single transparent cover plate covering the plurality of solar cells. And a solar cell module having a transparent cover plate bonded to the solar cell module. Also in the present invention, since the solar cell and its electrical connection member (interconnector) are covered with the transparent cover plate, the influence of these on the electromagnetic environment of the universe is reduced. In addition, a plurality of the solar cell modules can be used by being installed two-dimensionally on one substrate. Therefore, the workability of handling and installing the solar cell is improved.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings.
FIG. 1 shows a solar cell module 19 according to an embodiment of the present invention.
FIG. As shown in the figure, the solar cell module 19 includes one substrate 15, a plurality of solar cells 13 arranged in a plane on the substrate 15 and bonded by an adhesive 14, and a plurality of solar cells 13. And a cover glass (hereinafter, referred to as glass) 11 that covers the solar cell 13 and the interconnector 16. The glass 11 is bonded to the solar cell 13 and the interconnector 16 with an adhesive 12.

The solar cell module 19 is formed by covering a plurality of solar cells 13 with a single glass 11, and the solar cells 13 may be housed in the glass 11. There is no need to increase the positioning accuracy.

The adhesive 12 does not protrude from the upper surface of the glass 11 except for the outer peripheral portion. Also, although not shown, if the interconnector 16 has a structure having a stress relief portion, the stress is alleviated even if thermal strain occurs due to the thermal environment in space, and the peeling of the adhesive 12 and Damage to the solar cell 13 and the glass 11 is reduced.

FIG. 2 shows a solar cell module 1 according to this embodiment.
9 is a plan view, and FIG. 3 is a side view. However, for simplification of the drawing, FIG. 2 shows a state where the substrate 15 has been removed. In these figures, five solar cells 13 on the right and left sides are bonded between the glass 11 and the substrate 15 as shown in FIG. 2, and the bypass diode 17, the blocking diode 29, and the bus bar 18 are further bonded.

Therefore, all the electric circuit components necessary for the modules such as the solar cell 13, the interconnector 16, the bus bar 18, the bypass diode 17, and the blocking diode 29 are covered with the glass 11, so that they can be protected from the space environment. it can. An example of an electric circuit diagram at this time is shown in FIG.

As shown in FIG. 4, the solar cell module 19
Then, two sets of series circuits in which five solar cells 13 are connected in series by an interconnector 16 are respectively connected to a bus bar 18.
Are further connected in series to form one power generation circuit. One end of the power generation circuit is drawn out to the outside by a bus bar 18, and the other end is drawn out to the outside via a blocking diode 29 in series. A bypass diode 17 is connected to this power generation circuit in parallel.

FIG. 4 shows four solar cell modules 1
9 shows an example of a general circuit for supplying power from a series-parallel circuit 9 to a load L via a switch S, and an auxiliary battery B is inserted in parallel to a series-parallel circuit of a solar cell module 19.

When the solar cell module 19 is irradiated with light, the electromotive force supplies power to the load L and charges the battery B. When one of the solar cell modules 19 is no longer irradiated with light, the current from the other solar cell module 19 is supplied to the load L and the battery B through the bypass diode 17 of the unirradiated solar cell module 19. When the electromotive voltage of the solar cell module 19 decreases and a reverse voltage is applied from the battery B, the action of the blocking diode 29 causes the solar cell module 1 to operate.
9 is protected.

Next, the ten solar cell modules 19 are electrically connected in series or
FIG. 5 shows a solar cell panel 22 mounted on the top of the solar cell panel 5.

FIG. 6 shows another embodiment of the present invention, in which a solar cell 13 has a shape with both shoulders cut out, and the connection between adjacent solar cell modules 19 is formed by the space in the notch. It is performed using. The glass 11
Also has a cutout portion corresponding to the connection portion, and a cover glass (not shown) is bonded to the cutout portion after the connection operation is completed. The connection between the modules 19 is performed by soldering or welding.

FIGS. 7 and 8 show a solar cell module 1 containing blocking diodes 29 having different shapes.
FIG. 7 is an enlarged view of a main part showing a situation in which two adjacent solar cell modules 13 are connected to each other in a modified example of FIG. 3; FIG. 7 shows a case where the blocking diode 29 has a triangular plate shape; The case where it is a rectangular plate shape having substantially the same width as that of FIG.

FIG. 9 is a plan view showing another embodiment of the present invention. In the figure, a solar cell module 22 is a combination of four solar cell modules 19a and four solar cell modules 19b. The solar cell module 19a has a series circuit of two sets of solar cells 13, a bypass diode 17 and a blocking diode 29, and the solar cell module 19b has one set of solar cells 1
Only three series circuits are provided.

Then, the solar cell modules 19a and 19
b, the solar cell module 1 of FIG.
9 is obtained.
Therefore, it is effective to cover the long circuit of the solar cell module with one piece of glass when workability and handleability deteriorate. The solar cell modules 19a and 19b are all covered with the glass 11 as shown in FIG.

FIGS. 10 to 14 are cross-sectional views of essential parts showing a modification of the bonding portion of the solar cell 3. FIG. 10 shows an example in which the projections 34 are provided on the glass 11 to determine the positions of the solar cells 13 so that the plurality of solar cells 13 can be easily bonded. The projections 34 are formed by a method of shaving the surface of the glass 11 by mechanical treatment or etching treatment with an alkali or the like when forming the glass 11, a method of attaching a glass or ceramic material to be the projections 34 to the glass 11, or the like.

Since the thermal expansion coefficient of the glass 11 is larger than the material of the solar cell 13 and the substrate 15 (FIG. 1), thermal distortion occurs due to the thermal environment in the universe, and the adhesive 12 peels off and the solar cell This leads to breakage of the cell 13 and the glass 11. In order to prevent this, as shown in FIG. 11, the solar cells 1 are placed between the solar cells 13.
A member 35 having a higher coefficient of thermal expansion and lower rigidity than that of No. 3 is installed. Thereby, thermal distortion can be reduced.

When a silicone adhesive is used as the adhesive 12, the temperature of the silicone adhesive is low (−1).
(00 ° C.), a sudden change in physical properties occurs, and the coefficient of thermal expansion, the elastic modulus, and the like fluctuate by several orders of magnitude. For this reason, peeling of the silicone adhesive and breakage of the solar cell 13 or the glass 11 may be caused. This effect is particularly large in the case of a large glass 11 or a large area adhesive.

Therefore, as shown in FIG. 12, a member 36 for dividing the adhesive 12 is provided between the solar cells so that the adhesive 12 does not form one continuous layer. The materials of the members 35 and 36 include silicone resin, epoxy resin, and acrylic resin.

The glass 11 may be a single piece of glass by laminating a plurality of small pieces of glass with a material having a smaller coefficient of thermal expansion than that of the glass. Thereby, the glass 1
The mechanical or thermal stress applied to 1 is alleviated, and the glass 11 is hardly broken.

The glass 11 is provided with scratches or slits on its surface in advance, so that when the glass 11 is subjected to mechanical or thermal stress, it is broken between the solar cells 3. Good. As a result, it is possible to avoid serious damage such as breaking of the solar cell 13.

FIG. 13 shows a structure in which a member 37 is provided on the substrate 15 for positioning the solar cell 13 or dividing the adhesive. As shown in FIG. 14, the member 37 has a sharpened tip and high reflection characteristics so that sunlight 38 is reflected and enters the solar cell 13. Due to this reflection, more sunlight is irradiated on the surface of the solar cell 13. For this reason, the power generation amount of the solar cell module increases. The end of the member 37 may be formed by evaporating aluminum or silver to improve the reflectance.

FIG. 17 is a side view showing still another embodiment of the present invention. As shown in the figure, in the solar cell module 19a, a plurality of solar cells 13 are arranged in a plane, and they are arranged in parallel and in series in the interconnector 1.
6, the solar cell 13 and the interconnector 16 are covered with one piece of glass 11, and the solar cell 13 and the interconnector 16 are attached to the lower surface of the glass 11 with an adhesive 12 such as a silicone adhesive. Is stuck. That is, the solar cell module 1 in this embodiment
9a is the substrate 1 from the solar cell module 19 shown in FIG.
5 is formed.

FIGS. 18 and 19 are a plan view and a side view, respectively, showing a power generation circuit constituted by using eight solar cell modules 19a. Here, eight solar cell modules 1
9a are electrically connected in series and parallel to each other to form one power generation circuit. Also in this embodiment, the solar cell 13
And the interconnector 16 is covered with the glass 11, so that the influence of the electromagnetic environment in space is reduced. Also,
Since the solar cells can be installed on the substrate in units of modules, handling and installation work of the solar cells becomes easy.

[0047]

According to the present invention, since a plurality of solar cells are bonded to one piece of glass, precise alignment between the glass and the solar cells becomes unnecessary, and the adhesive sticks out to the upper surface of the glass. , The assembly work is greatly simplified. When precise alignment between the glass and the solar cell is required, the work can be simplified by using glass or the like provided with a projection for alignment of the solar cell in advance.

Further, since the electrical connecting members between the solar cells are also covered with the glass, the interaction between the connecting members and the electromagnetic environment in space is reduced. In addition, by installing a material having a higher coefficient of thermal expansion and a lower rigidity than the solar cells between adjacent solar cells, thermal distortion due to the thermal environment in space is alleviated. Cell and glass breakage is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a solar cell module according to an embodiment of the present invention.

FIG. 2 is a plan view of the solar cell module shown in FIG.

FIG. 3 is a side view of the solar cell module shown in FIG.

4 is an electric circuit diagram showing a circuit of the solar cell module shown in FIG. 2 and an example of its use.

FIG. 5 is a plan view showing an example of a panel incorporating the solar cell module shown in FIG.

FIG. 6 is a plan view showing a solar cell module according to another embodiment of the present invention.

FIG. 7 is an essential part enlarged view showing a modified example of the solar cell module of the present invention.

FIG. 8 is an essential part enlarged view showing another modified example of the solar cell module of the present invention.

FIG. 9 is a plan view showing another embodiment of the solar cell module of the present invention.

FIG. 10 is a cross-sectional view of a principal part showing another embodiment of the solar cell module of the present invention.

FIG. 11 is a sectional view of a main part showing another embodiment of the solar cell module of the present invention.

FIG. 12 is a sectional view of a main part showing another embodiment of the solar cell module of the present invention.

FIG. 13 is a sectional view of a main part of another embodiment of the solar cell module of the present invention.

FIG. 14 is an enlarged view of a main part of FIG.

FIG. 15 is a cross-sectional view of a main part of a conventional solar cell module.

FIG. 16 is an enlarged sectional view of a main part of a conventional solar cell module.

FIG. 17 is a side view showing another embodiment of the solar cell module of the present invention.

FIG. 18 is a plan view showing an example of arrangement of the solar cell modules shown in FIG.

FIG. 19 is a side view showing an example of arrangement of the solar cell modules shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Glass 12 Adhesive 13 Solar cell 14 Adhesive 15 Substrate 16 Interconnector 19 Solar cell module

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuo Saga 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Inside (72) Inventor Keiji Shimada 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Sharp Co., Ltd. F term (reference) 5F051 EA03 EA18 JA07 JA08 KA07

Claims (19)

[Claims] 1. A single substrate, a plurality of solar cells arranged in a plane on the substrate, and a connection member for electrically connecting the plurality of solar cells to form an electric circuit;
A solar cell module comprising: a single transparent cover plate that covers the plurality of solar cells and a connection member. 2. The solar cell module according to claim 1, further comprising a protection element connected to the electric circuit between the substrate and the transparent cover plate. 3. The solar cell module according to claim 2, wherein the protection element is a bypass diode or a blocking diode. 4. The solar cell module according to claim 2, wherein the solar cell has a notch in a part thereof, and the protection element is provided in the notch. 5. The solar cell module according to claim 1, wherein the solar cell has a notch in a part thereof and is connected to an external circuit at the notch. 6. A solar cell module obtained by combining a plurality of the solar cell modules according to claim 1. 7. The solar cell module according to claim 1, wherein the transparent cover plate is made of cerium-doped glass and has a thickness of 50 to 200 μm. 8. The solar cell has a thickness of 50 to 200 μm.
The solar cell module according to claim 1, wherein 9. The solar cell module according to claim 1, wherein the solar cell is bonded to a transparent cover plate. 10. The solar cell module according to claim 1, wherein the transparent cover plate has a projection projecting toward the solar cell in order to position each solar cell. 11. A plurality of solar cells are adhered to a transparent cover plate via an adhesive layer, and provided with a separating member interposed between adjacent solar cells to isolate the adhesive layer for each solar cell. The solar cell module according to claim 1. 12. A reflection member extending from the substrate and passing between the solar cells and having a tip abutting on the transparent cover plate, wherein the tip of the reflection member reflects light incident from the transparent cover plate to the solar cells. The solar cell module according to claim 1, which is formed as follows. 13. The solar cell module according to claim 1, further comprising a thermal expansion absorbing member between adjacent solar cells. 14. The solar cell module according to claim 13, wherein the thermal expansion absorbing member has lower rigidity than the solar cell. 15. The transparent cover plate has a slit-like flaw so as to be broken by mechanical or thermal stress.
The solar cell module as described. 16. A solar cell panel comprising: a plurality of the solar cell modules according to claim 1; and a base on which the plurality of the solar cell modules are mounted. 17. The solar cell module according to claim 4, wherein the protection element has an outer shape corresponding to the shape of the notch. 18. A plurality of solar cells and a transparent cover, comprising: a plurality of solar cells electrically connected to each other and arranged in a plane; and a single transparent cover plate covering the plurality of solar cells. A solar cell module with a plate bonded. 19. A solar cell panel in which a plurality of the solar cell modules according to claim 18 are planarly arranged on one substrate.