JP2011086960A - Solar cell panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell panel allowing a circumferential region of a solar cell module to be appropriately polished by appropriately performing a groove processing process of the solar cell module and shortening the groove processing process without degrading the solar cell module or long term reliability. <P>SOLUTION: The solar cell panel includes a substrate 1 and a plurality of power generation cells 5. The substrate 1 includes a first side 1a, a second side 1b, a third side 1c and a fourth side 1d. The plurality of power generation cells 5 are formed on the substrate 1, arranged along the first side 1a, and connected in series to one another. The solar cell panel includes a first groove 15a along the first side 1a in the vicinity of the first side 1a, and a second groove 15b along the second side 1b in the vicinity of the second side 1b. A groove in the vicinity of the third side 1c along the third side 1c, and a groove in the vicinity of the fourth side 1d and along the fourth side 1d do not exist. The first groove 15a and the second groove 15b extend from the surfaces of the plurality of the power generation cells 5 to the surface of the substrate 1, and extend to the vicinities of the third sides 1c and the fourth side 1d so as not to reach ends of the substrate 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solar cell panel of a thin film silicon solar cell such as an amorphous silicon solar cell, a microcrystalline silicon solar cell, and a tandem solar cell in which an amorphous silicon solar cell and a microcrystalline silicon solar cell are stacked. In particular, the present invention relates to a solar cell panel capable of improving the productivity and long-term reliability of solar cells.

  A thin-film silicon-based solar cell (hereinafter referred to as a solar cell panel) formed by laminating a silicon-based thin film on a light-transmitting substrate is known. FIG. 10 is a diagram showing a conventional solar cell panel. (A) is a top view, (b) is a XX partial sectional view in (a).

  The solar cell panel includes a substrate 101 and a solar cell module 106. The solar cell module 106 is provided inside the peripheral region 114 on the surface of the substrate 101. The solar cell module 106 includes a plurality of solar battery power generation cells 105, and includes an X-direction insulating groove 115 and a Y-direction insulating groove 113 provided on the entire inner periphery of the end portion of the solar cell module 106. The X direction insulating groove 115 extends in the X direction. The Y direction insulating groove 113 extends in the Y direction. The solar power generation cell 105 includes a transparent conductive layer 102, a photoelectric conversion layer 103, and a back electrode layer 104. The transparent conductive layer 102 is provided on the substrate 101 and is divided so as to correspond to the plurality of solar battery power generation cells 105 by grooves 110 extending in the Y direction. The photoelectric conversion layer 103 is provided on the transparent conductive layer 102 and is divided so as to correspond to the plurality of solar battery power generation cells 105 by grooves 111 extending in the Y direction. The back electrode layer 104 is provided on the photoelectric conversion layer 103 and is divided so as to correspond to the plurality of solar battery power generation cells 105 by grooves 112 extending in the Y direction.

  As described above, the conventional solar cell panel has the insulating separation grooves (the X-direction insulating groove 115 and the Y-direction insulating groove 113) on the entire inner periphery of the end portion of the solar cell module 106 (for example, patents). No. 3243227, Japanese Patent No. 3243229, Japanese Patent No. 3243232). Such a separation groove electrically separates the short-circuit occurrence portion between the transparent conductive layer 102 and the back electrode layer 104 in the vicinity of the end face of the solar battery module 106 of the solar battery power generation cell 105, thereby short-circuiting the solar power generation cell 105. It is important to prevent the occurrence. Moreover, it is effective also in suppressing that external moisture etc. penetrate | invade from the area | region sealed around the edge part of the solar cell panel, and the performance of the solar cell module 106 falls. However, since the separation groove (same for the groove 110) reaches the end of the substrate, external moisture may enter the solar battery power generation cell 105 from the portion of the groove reaching the substrate end. In that case, the solar battery power generation cell 105 is deteriorated by the moisture, which becomes a factor of reducing long-term reliability. A technique capable of further improving long-term reliability is desired. In addition, since a separation groove is provided on the entire inner periphery of the end portion of the solar cell module 106, this is a process that takes processing time. A technology capable of improving the productivity by suppressing the performance deterioration of the solar cell module 106 and improving the long-term reliability, and shortening the processing time required for the insulating groove processing at the end of the solar cell module 106. desired.

  Further, in the conventional solar battery panel, the film of the solar battery power generation cell existing in the peripheral region 114 of the solar battery module is removed by polishing (for example, JP-A-8-83923, JP-A-2003-142717). Issue gazette). Thus, eliminating the film in the peripheral region 114 means that the sheet enclosing the solar cell module 106 (not shown, and describing that the back sheet is bonded through EVA later) and the exposed surface of the peripheral region 114 are exposed. It is important to improve the adhesion of the solar cell module 106 with the sheet. However, the film of the surrounding region 114 is not sufficiently removed and the adhesive strength is insufficient, the film partially remains and a cavity remains in the bonded part, or the substrate 101 is exposed when the film is removed. If a groove is formed by polishing in the direction intersecting with the edges around the substrate, streaks (several tens of μm) that may cause capillary action remain between the sheet and the substrate 101, from which the solar cell There is a risk of external moisture entering the power generation cell 105. In that case, the solar battery power generation cell 105 is deteriorated by the moisture, which becomes a factor of reducing long-term reliability. The situation that causes this performance degradation has been revealed by recent outdoor exposure tests over a long period of time, but the countermeasure has not been specified. A technique that can appropriately polish the surrounding region 114 without reducing long-term reliability is desired. Here, the silicon system is a general term for materials including silicon such as silicon (Si), silicon carbide (SiC), and silicon germanium (SiGe), and the microcrystalline silicon system is an amorphous silicon system, that is, non-silicon. It means a silicon system other than the crystalline silicon system, and includes a polycrystalline silicon system and a crystalline silicon system containing amorphous. In addition, the thin film silicon type includes the amorphous silicon type, the microcrystalline silicon type, and the tandem type in which the amorphous silicon type and the microcrystalline silicon type are stacked.

Japanese Patent No. 3243227 Japanese Patent No. 3243229 Japanese Patent No. 3243232 JP-A-8-83923 JP 2003-142717 A

  Therefore, the objective of this invention is providing the solar cell panel which can perform the process of the groove processing of a solar cell module appropriately so that long-term reliability may be improved more.

  Another object of the present invention is to provide a solar cell panel capable of improving productivity by shortening the groove processing step at the end of the solar cell module without degrading the performance of the solar cell module.

  Still another object of the present invention is to provide a solar cell panel that can appropriately polish the film of the power generation cell in the peripheral region of the solar cell module without deteriorating long-term reliability.

  Hereinafter, means for solving the problem will be described using the numbers and symbols used in the best mode for carrying out the invention. These numbers and symbols are added in parentheses in order to clarify the correspondence between the description of the claims and the best mode for carrying out the invention. However, these numbers and symbols should not be used for interpreting the technical scope of the invention described in the claims.

In order to solve the above problems, the solar battery panel of the present invention includes a substrate (1) and a plurality of power generation cells (5). The substrate (1) includes a first side (1a), a second side (1b) facing the first side (1a), and a third side between the first side (1a) and the second side (1b). The light-transmitting material has a side (1c) and a fourth side (1d) opposite to the third side (1c). The plurality of power generation cells (5) are provided on the substrate (1), are aligned along the first side (1a), and are connected in series to each other. Each of the plurality of power generation cells (5) includes a transparent conductive layer (2), a photoelectric conversion layer (3), and a back electrode layer (4) in this order on the substrate (1), and the first side (1a) A groove extending from the back electrode layer (4) which is the surface of the plurality of power generation cells (5) to the surface of the substrate (1) in the vicinity of the first groove (15a) along the first side (1a), A second groove (15b) along the second side (1b) is provided in the vicinity of the second side (1b). There is no groove along the third side (1c) in the vicinity of the third side (1c) and no groove along the fourth side (1d) in the vicinity of the fourth side (1d). The first groove (15a) and the second groove (15b) extend to the vicinity of the third side (1c) and the fourth side (1d) so as not to reach the end of the substrate (1).
Here, the photoelectric conversion layer (3) may constitute a tandem solar cell in which a p-layer, an i-layer, and an n-layer of thin film silicon are laminated, and further, a plurality of these sets are laminated. The first groove (15a) and the second groove (15b) are insulating grooves, and are formed between the transparent conductive layer (2) and the back electrode layer (4) in the vicinity of the end face of the solar cell module (6) of the power generation cell (5). This is important in order to electrically isolate the short-circuit occurrence portion and prevent the short-circuit occurrence of the power generation cell (5). Moreover, it is effective also in suppressing that external moisture etc. penetrate | invade from the area | region sealed around the edge part of the solar cell panel, and reduce the performance of a solar cell module (6).
Since the first groove (15a) and the second groove (15b) do not reach the end of the substrate (1), external moisture enters from the end of the substrate (1), and the first groove (15a) and the second groove (15b). Capillary phenomenon is generated in the groove (15b) and moisture can be prevented from entering the solar cell module (6). In addition, since there is a step of removing the film of the power generation cell (5) existing in the peripheral region (4) of the solar cell module by polishing, a groove and a fourth side along the third side (1c) It has been found that the groove along (1d) can be omitted. Thereby, since there is no groove along the third side (1c) and no groove along the fourth side (1d), the processing time of the groove processing step can be shortened. That is, it is a groove extending from the back electrode layer, which is the surface of the plurality of power generation cells, to the surface of the substrate, and suppresses performance degradation of the solar cell module (6) to improve long-term reliability, and solar cell module It becomes possible to shorten the process of grooving the end portion of the.

In the solar cell panel, it is preferable that the ends of the first groove (15a) and the second groove (15b) are separated from the end of the substrate (1) by a distance (d1) of 5 mm or more and 10 mm or less.
In order to suppress the intrusion of external moisture from the edge of the substrate, it is desirable that the sound adhesion area with the sheet in the peripheral area (4) is 5 mm or more, and the solar cell module ( In order to increase the area of 6), it is desirable that the area is 10 mm or less.

Said solar cell panel WHEREIN: It is preferable that a some electric power generation cell (5) is provided with the 1st film | membrane (2) formed into a film on a board | substrate (1). The first film (2) has a third groove (10) extending in a direction different from the directions of the first side (1a) and the second side (1b). The third groove (10) extends from the surface of the first film (2) to the surface of the substrate (1), and the first side (1a) and the second side (1b) so as not to reach the end of the substrate (1). It extends to the vicinity.
The third groove (10) is necessary to configure a plurality of strip-shaped power generation cells (5) connected in series on the substrate (1). Since the third groove (10) does not reach the end of the substrate (1), as with the first groove (15a) and the second groove (15b), which are the aforementioned insulating grooves, the end of the substrate (1) is externally connected. It is possible to prevent moisture from entering. That is, the step of groove processing of the solar cell module can be appropriately performed so as to further improve the long-term reliability.

In the above solar cell panel, the end of the third groove (10) is preferably separated from the end of the substrate (1) by a distance (d2) of 5 mm or more and 10 mm or less.
This distance is preferable in terms of widening the area of the solar cell module while securing the surrounding area by the same determination as the first groove (15a) and the second groove (15b) which are the insulating grooves described above.

  In order to solve the above-described problems, a method for manufacturing a solar cell panel according to the present invention includes (a) a first side (1a), a second side (1b) facing the first side (1a), and a first side. A first side on a substrate (1) having a third side (1c) between (1a) and a second side (1b) and a fourth side (1d) opposite the third side (1c); A step of forming a plurality of power generation cells (5) arranged along (1a) and connected in series with each other; (b) a first groove along the first side (1a) in the vicinity of the first side (1a); (15a) and forming a second groove (15b) along the second side (1b) in the vicinity of the second side (1b). A groove and a fourth side extending along the third side (1c) in the vicinity of the third side (1c) extend from the back electrode layer (4) which is the surface of the plurality of power generation cells (5) to the surface of the substrate (1). A groove along the fourth side (1d) is not formed in the vicinity of 1d). The first groove (15a) and the second groove (15b) extend from the back electrode layer (4), which is the surface of the plurality of power generation cells (5), to the surface of the substrate (1) and reach the end of the substrate (1). So as not to extend to the vicinity of the third side and the fourth side (1d). However, each of the plurality of power generation cells (5) includes a transparent conductive layer (2), a photoelectric conversion layer (3), and a back electrode layer (4) in this order on the substrate (1).

  In the method for manufacturing a solar cell panel, the step (b) includes (b1) a distance (d1) in which the ends of the first groove (15a) and the second groove (15b) are 5 mm or more and 10 mm or less from the end of the substrate (1). It is preferable to include a step of forming the first groove (15a) and the second groove (15b) so as to be separated from each other.

  In the above solar cell panel, the step (a) includes (a1) a step of forming the transparent conductive layer (2) on the substrate (1), (a2) the first side (1a) and the transparent conductive layer (2) It is preferable to include a step of forming a third groove (10) extending in a direction different from the direction of the second side (1b). The third groove (10) extends from the surface of the transparent conductive layer (2) to the surface of the substrate (1), and the first side (1a) and the second side (1b) so as not to reach the end of the substrate (1). It extends to the vicinity.

  In the above solar cell panel, the step (a2) includes: (a21) the third groove (10) so that the end of the third groove (10) is separated from the end of the substrate (1) by a distance (d2) of 5 mm to 10 mm. ) Is preferably included.

In the above solar cell panel manufacturing method, (c) a sheet material is used to remove a part of the film for the plurality of power generation cells (5) laminated on the substrate (1) and to expose the exposed surface. The method further includes a step of forming a bonding surface of the material. The step (c) includes (c1) a step of grinding the film of the plurality of power generation cells (5) in the peripheral portion (14) of the substrate (1) by rotating grinding stone polishing, and a substrate after the steps (c2) and (c1). It is preferable to include a step of scouring the film for the plurality of power generation cells (5) in the peripheral edge (14) of (1) by blast polishing.
A portion of the film of the power generation cell (5) in the peripheral region of the solar cell module (6) is removed, and the portion exposed on the substrate (1) is replaced with a solar cell via EVA (ethylene vinyl acetate copolymer) or the like. It is set as the adhesive surface with the back sheet which encloses a module (6). It is desirable that the substrate (1) is exposed on the adhesive surface, and if the conductive portion of the transparent conductive layer (2) remains, the insulating characteristics may be deteriorated. At this time, if minute scratches or grooves of several tens of μm level generated in the exposed portion on the substrate (1) remain in the direction intersecting the sides around the substrate (1), the sealing portion at the end of the solar cell panel From the above, it has been found that moisture may enter the solar cell module (6) when external moisture enters.
By roughing with a rotating grindstone and removing the remaining film by blasting, the film can be reliably removed while suppressing the formation of scratches and grooves while suppressing a decrease in production efficiency. As a result, external moisture penetrates into the solar cell module (6) due to scratches or grooves that generate capillary action in the adhesion portion of the peripheral region of the solar cell module (6) with the back sheet via EVA or the like. Thus, the surrounding area of the solar cell module can be properly polished without deteriorating long-term reliability.

In the above solar cell panel manufacturing method, the first side (1a), the second side in each of the cases where the step (c2) is performed after the steps (d) and (c1) and the case where the step (c2) is not performed. The method further comprises the step of polishing the peripheral portion (14) of the substrate (1) with a grindstone while preventing the polishing groove formed by the grindstone from traversing the side (1b), the third side (1c) and the fourth side (1d). It is preferable to do.
The grindstone is preferably polished with the same count or finer. Since the peripheral edge portion (14) is finished and polished so as not to cross each side of the substrate (1), the edge from the edge of the substrate (1) passes through the scratches and grooves from the edge of the solar cell panel toward the inside of the solar cell module. The path through which the external moisture enters is cut off, and the ingress of moisture can be prevented. That is, external moisture may infiltrate into the solar cell module (6) due to scratches or grooves that generate capillary action at the portion of the solar cell module (6) that is bonded to the back sheet via EVA or the like in the peripheral region. Thus, the surrounding area of the solar cell module can be appropriately polished so as to improve the long-term reliability.

  According to the present invention, the performance of the solar cell module is suppressed, the long-term reliability is not lowered, and the groove processing step of the solar cell module is appropriately performed, and the processing time of the groove processing step is shortened. It is possible to improve the long-term reliability by appropriately polishing the surrounding area of the module.

FIG. 1 is a top view showing a configuration of an embodiment of a solar cell panel of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the solar cell module in the embodiment of the solar cell panel of the present invention. FIG. 3 is an enlarged schematic view of a portion A in FIG. FIG. 4 is a diagram relating to the surrounding area in the embodiment of the solar cell panel of the present invention. FIG. 5 is a schematic view showing an embodiment of a method for producing a solar cell panel of the present invention. FIG. 6 is a schematic view showing an embodiment of a method for producing a solar cell panel of the present invention. FIG. 7 is a schematic view showing an embodiment of a method for producing a solar cell panel of the present invention. FIG. 8 is a schematic view showing an embodiment of a method for producing a solar cell panel of the present invention. FIG. 9 is a table showing a performance comparison according to the processing mode of the insulating groove of the solar cell panel of the present invention. FIG. 10 is a diagram showing a conventional solar cell panel.

  Hereinafter, embodiments of the solar cell panel of the present invention will be described with reference to the accompanying drawings.

  First, the configuration of the embodiment of the solar cell panel of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a top view showing a configuration of an embodiment of a solar cell panel of the present invention. The solar cell panel includes a substrate 1 and a solar cell module 6.

  The substrate 1 includes a first side 1a, a second side 1b facing the first side 1a, a third side 1c between the first side 1a and the second side 1b, and a third side 1c facing the third side 1c. 4 sides 1d. The substrate 1 has translucency, and for example, glass is suitable.

  The solar cell module 6 is provided inside the peripheral region 14 without a film on the surface of the substrate 1. The solar cell module 6 includes a plurality of solar battery power generation cells 5 (described later), and includes an X-direction insulating groove 15 a and an X-direction insulating groove 15 b provided inside the end of the solar cell module 6.

  The X-direction insulating groove 15a is provided in the vicinity of the first side 1a along the first side 1a. The X-direction insulating groove 15b is provided in the vicinity of the second side 1b along the second side 1b. The X direction insulating groove 15 a and the X direction insulating groove 15 b extend from the back electrode layer 4 which is the surface of the plurality of power generation cells 5 to the surface of the substrate 1 in the depth direction. And although it has reached the surface of the substrate 1, it is preferable not to extend into the substrate 1 in order to ensure the strength of the substrate 1. On the other hand, the length direction extends in the X direction. One end extends to the vicinity of the third side 1c, and the other end extends to the vicinity of the fourth side 1d. Both ends do not reach the end of the substrate 1. The width of the X direction insulating groove 15 is, for example, 50 to 100 μm.

  FIG. 2 is a cross-sectional view showing the configuration of the solar cell module 6 in the embodiment of the solar cell panel of the present invention. A part of XX cross section of FIG. 1 is shown. Each of the plurality of solar battery power generation cells 5 is provided on the substrate 1, arranged along the first side 1 a, and connected to each other in series. The power generation cell 5 includes a transparent conductive layer 2, a photoelectric conversion layer 3, and a back electrode layer 4.

  The transparent conductive layer 2 is formed on the substrate 1 and divided by a groove 10 extending in the Y direction so as to correspond to each of the plurality of strip-shaped solar cells 5. The groove 10 extends from the surface of the transparent conductive layer 2 to the surface of the substrate 1 in the depth direction. It extends to the vicinity of the first side 1 a and the second side 1 b in the length direction, and does not reach the end of the substrate 1. The width of the groove 10 is, for example, 10 to 50 μm.

  The photoelectric conversion layer 3 constitutes a tandem-type or triple-type solar cell in which p-layers, i-layers, and n-layers of thin film silicon are stacked, and further, a plurality of these stacked layers are stacked. The photoelectric conversion layer 3 is provided on the transparent conductive layer 2 and is divided so as to correspond to each of the plurality of solar cells 5 by a groove 11 extending in the Y direction in the vicinity of the groove 10. The groove 11 extends from the surface of the photoelectric conversion layer 3 to the surface of the transparent conductive layer 2 in the depth direction.

  The back electrode layer 4 is provided on the photoelectric conversion layer 3 and is divided so as to correspond to each of the plurality of solar cells 5 by a groove 12 extending in the Y direction in the vicinity of the groove 11. The groove 12 extends from the surface of the back electrode layer 4 to the surface of the photoelectric conversion layer 3 in the depth direction.

  FIG. 3 is an enlarged schematic view of a portion A in FIG. The end on the third side 1c side in the X-direction insulating groove 15a is separated from the end of the substrate 1 by a distance d1. Although not shown, the end on the fourth side 1d side in the X-direction insulating groove 15a is similarly separated from the end of the substrate 1 by a distance d1. Although not shown, the same applies to both ends of the X-direction insulating groove 15b. Since the X-direction insulating grooves 15 (15a, 15b) do not reach the end of the substrate by being separated from both ends of the substrate 1 by the distance d1, external moisture from the end of the solar cell panel is caused by the capillary action of the grooves. There is no risk of entering the solar cell module 6. That is, it is possible to prevent the solar battery power generation cell 5 from being deteriorated due to moisture intrusion from the X-direction insulating groove 15. Thereby, it is possible to appropriately perform the insulating groove processing step at the end of the solar cell module so as to further improve the long-term reliability.

  The distance d1 is preferably 10 mm or less because the area of the solar cell module 6 is as large as possible. On the other hand, when various comparative tests for suppressing the intrusion of external moisture from the end portion of the solar cell panel were performed, a healthy adhesion region with the back sheet via EVA or the like in the peripheral region 14 may be 5 mm or more. Since it has been found desirable, the distance d1 is preferably 5 mm or more.

  The end of the groove 10 on the first side 1a side is separated from the end of the substrate 1 by a distance d2. Although not shown, the end of the groove 10 on the second side 1b side is similarly separated from the end of the substrate 1 by a distance d2. By separating the both ends of the substrate 1 by the distance d2, the groove 10 does not reach the end of the substrate 1, so that there is no possibility of external moisture entering the solar cell 5 from the groove. That is, it is possible to prevent the solar battery power generation cell 5 from being deteriorated due to moisture intrusion from the groove 10. Thereby, it becomes possible to appropriately perform the groove processing step of the solar cell module so as to further improve the long-term reliability.

  The distance d2 is preferably 10 mm or less because the area of the solar cell module 6 is as large as possible. On the other hand, like the distance d1 in the insulating grooves 15a and 15b, since it is desirable that the sound adhesion region with the back sheet via the EVA or the like in the peripheral region 14 is 5 mm or more, the distance d2 is also preferably 5 mm or more.

  In the present invention, the back electrode layer 4 which is the surface of the plurality of solar cells 5 extends from the back electrode layer 4 to the surface of the substrate 1, near the third side 1 c and along the third side 1 c and the fourth side 1 d. There is no Y-direction insulating groove along the four sides 1d.

FIG. 9 is a table showing a performance comparison according to the processing mode of the insulating groove of the solar cell panel of the present invention by the inventors' experiment. The power generation characteristics of 10 solar cell panels manufactured under the conditions in each insulating groove were confirmed using a solar simulator of AM1.5 and global solar radiation standard sunlight (1000 W / m ² ). This is a comparative evaluation with an average value of measured values of a solar cell panel (FIG. 10) according to a conventional process having an insulating groove in the entire circumferential direction of the solar cell panel in the X and Y directions as 100%. The characteristics of the solar cell panel (FIG. 1) in which the insulating groove is processed only in the X direction according to the present invention are the same as those of the conventional solar cell panel (FIG. 10) for any of the open circuit voltage Voc, the short circuit current Isc, and the maximum output Pmax. There was no difference in initial performance.

On the other hand, in the solar cell panel in which the insulating groove was processed only in the Y direction as a comparative example, the performance was lowered particularly at the open circuit voltage Voc compared to the solar cell panel according to the conventional process. This is because when the film of the power generation cell 5 is polished in the peripheral region of the solar cell, which is performed in a step after the insulating groove step, an insulating effect similar to the insulating groove processing is obtained in the Y direction. It is possible to omit the directional insulation groove processing. However, in the X direction, when the film of the power generation cell 5 in the peripheral region is polished, the back electrode layer 4 and the transparent conductive layer 2 are likely to be short-circuited in the series connection region between the plurality of power generation cells 5. This is because the insulating groove in the X direction cannot be omitted.
Moreover, the confirmation experiment which simulated the severe conditions outdoors was also performed about the solar cell panel (FIG. 1) by this invention. After preliminarily stabilizing the performance by exposing to light with AM1.5 and solar radiation standard sunlight (1000 W / m ² ) for 20 hours, the high temperature and high humidity test (temperature 85 ° C., humidity 85%, JIS C 8938) It was confirmed that there was no change in performance at an evaluation time of 1000 hours.

  That is, even if the Y direction insulating groove was not provided, the initial performance equivalent to that having the Y direction insulating groove could be obtained. Therefore, it is possible to shorten the processing time of the insulating groove processing step at the end of the solar cell module while suppressing the performance deterioration of the solar cell module.

  FIG. 4 is a diagram relating to the surrounding area in the embodiment of the solar cell panel of the present invention. The peripheral region 14 is a region where the solar cell film formed on the substrate is removed by polishing. In order to remove the film in the surrounding region 14, one of the methods of polishing and blast polishing (using alumina particles having a particle diameter of about 10 to 50 μm) is usually performed with a rotating grindstone. However, it is difficult to control the thickness of the film to be removed in the grinding of the rotating grindstone. If the substrate 1 is excessively shaved, the strength of the substrate 1 is lowered, or conversely, if the transparent conductive layer 2 remains, the EVA is passed through EVA or the like. There is a tendency to cause a problem of a poorly bonded portion to be joined to the back sheet and a problem of generating a decrease in insulating properties via the remaining transparent conductive layer 2. On the other hand, in the blast polishing, masking for separating the removal / non-removal region is complicated and difficult, and when the film to be removed is thick, the masking is easily consumed or deformed easily.

  In the present invention, in the initial stage, all of the back electrode layer, the photoelectric conversion layer, and a part of the transparent conductive layer 2 occupying 50% or more of the total laminated film thickness of the solar battery power generation cell 5 are roughened by polishing a rotating grindstone. The remaining film is scraped by blast polishing. Thereby, the precision of polishing and its reliability can be improved. Thereby, it is possible to prevent a problem that the substrate 1 is excessively shaved or the transparent conductive layer 2 remains. As a result, the adhesion state between the back sheet and the substrate 1 via EVA or the like is in close contact with each other and the adhesive strength is in a good state, and external moisture enters the solar power generation cells 5 from here. Can be prevented, and long-term reliability can be maintained.

  In FIG. 4, after removing the film in the peripheral region 14 by only rotating grindstone polishing or by a combination of rotary grindstone polishing and blast polishing, the present invention further performs hairline processing in the peripheral region 14. A polishing direction 21 indicates an approximate position and direction for performing a hairline process. The hairline treatment increases the adhesion between the back sheet and the substrate 1 through EVA or the like that covers the solar cell module 6 used in the post-process, and crosses the peripheral region 14 from the edge of the solar cell panel across the peripheral region 14. 6 is a finishing process of the bonding surface (peripheral region 14) performed in order to eliminate the scratches and grooves due to polishing extending to the 6th side and cut off the ingress of external moisture.

  In the process until the film of the surrounding region 14 is removed, if for some reason, scratches or grooves extending across the surrounding region 14 toward the solar cell module 6 remain, the outside air is generated inside the solar cell module 6 due to capillary action. There is a risk of intrusion of moisture. For this reason, as a final treatment, the surrounding area 14 after removing the film is lightly polished with a grindstone to form a hairline. As a result, even if scratches and grooves remain, they are polished and removed, and even in the remaining scratches and grooves, the grooves extending to the solar cell module 6 side across the peripheral region 14 are cut off. The adhesion of the adhesive surface with the back sheet and the reliability of encapsulation can be made extremely high.

  If a deep hairline is left by overpolishing, the adhesion of the adhesive surface with EVA or the like may be deteriorated, which may have an adverse effect. Therefore, the finishing grindstone used for the hairline treatment is preferably a soft abrasive. As such an abrasive, for example, silicon carbide-based # 400 to # 1200 can be used. The finishing grindstone may be automatically run in the surrounding area 14 while applying a light load as a rotating grindstone, or may be performed manually. However, the finishing grindstone is moved in the polishing direction 21 so as not to cross the edge of the substrate 1 and go outward. Thus, by polishing without protruding from the surrounding region 14, even if scratches or grooves remain, they do not reach the end of the substrate 1, so there is a possibility that external moisture may enter the solar cell 5 from the grooves. Disappear. That is, it is possible to prevent the degradation of the solar battery power generation cell 5 due to moisture from scratches and grooves. Thereby, long-term reliability can be improved more, improving the adhesiveness with the back sheet via EVA etc.

  Next, an embodiment of a method for manufacturing a solar cell panel of the present invention will be described. Here, an example in which a single-layer amorphous silicon thin film solar cell is used as the solar cell power generation cell 5 on a glass substrate as the substrate 1 will be described. 5-8 is the schematic which shows embodiment of the manufacturing method of the solar cell panel of this invention.

(1) FIG. 5 (a)
A soda float glass substrate (1.4 m × 1.1 m × plate thickness: 4 mm) is used as the substrate 1. It is desirable that the end face of the substrate is corner chamfered or rounded to prevent breakage.
(2) FIG. 5 (b)
A transparent electrode film mainly composed of a tin oxide film (SnO ₂ ) is formed as a transparent conductive layer 2 at a temperature of about 500 ° C. to about 500 ° C. using a thermal CVD apparatus. At this time, a texture with appropriate irregularities is formed on the surface of the transparent electrode film. As the transparent conductive layer 2, in addition to the transparent electrode film, an alkali barrier film (not shown) may be formed between the substrate 1 and the transparent electrode film. As the alkali barrier film, a silicon oxide film (SiO ₂ ) is formed at a temperature of about 500 ° C. in a thermal CVD apparatus with a thickness of 50 to 150 nm.
(3) FIG. 5 (c)
Thereafter, the substrate 1 is placed on an XY table, and the first harmonic (1064 nm) of the laser diode-pumped YAG laser is incident from the film surface side of the transparent electrode film as indicated by the arrow in the figure. Pulse oscillation: Adjusting the laser power so as to be suitable for the processing speed as 5 to 20 kHz, the width of the transparent electrode film is formed so as to form the groove 10 in the direction perpendicular to the series connection direction of the power generation cells 5. Laser etching into 6-10 mm strips.
The groove 10 terminates the etching at a position 5 to 10 mm from the end of the substrate 1. The etching may be terminated by stopping the laser beam, but can be dealt with simply by installing a metallic masking plate in the non-laser etching region of the substrate 1. By terminating the etching at a position of 5 to 10 mm from the end of the substrate 1, an effective effect is exerted in suppressing external moisture intrusion into the solar cell module 6 from the end of the solar cell panel.
(4) FIG. 5 (d)
Using a plasma CVD apparatus, a p-layer film / i-layer film / n-layer film composed of an amorphous silicon thin film as the photoelectric conversion layer 3 is sequentially formed at a reduced pressure atmosphere of 30 to 150 Pa and about 200 ° C. The photoelectric conversion layer 3 is formed on the transparent conductive layer 2 using SiH ₄ gas and H ₂ gas as main raw materials. The p-layer, i-layer, and n-layer are stacked in this order from the sunlight incident side. In this embodiment, the photoelectric conversion layer 3 has a p-layer: B-doped amorphous SiC and a film thickness of 10 to 30 nm, an i-layer: amorphous Si and a film thickness of 250-350 nm, and an n-layer: p-doped microcrystalline Si. The film thickness is 30 to 50 nm. A buffer layer may be provided between the p layer film and the i layer film in order to improve the interface characteristics.
(5) FIG. 5 (e)
The substrate 1 is placed on an XY table, and the second harmonic (532 nm) of the laser diode-pumped YAG laser is incident from the film surface side of the photoelectric conversion layer 3 as indicated by an arrow in the figure. Pulse oscillation: 10 to 20 kHz, the laser power is adjusted so as to be suitable for the processing speed, and laser etching is performed so that the groove 11 is formed on the lateral side of about 100 to 150 μm of the laser etching line of the transparent conductive layer 2. .
(6) FIG. 6 (a)
As the back electrode layer 4, an Ag film / Ti film is sequentially formed by a sputtering apparatus at about 150 ° C. in a reduced pressure atmosphere. In this embodiment, the back electrode layer 4 is formed by stacking an Ag film: 200 to 500 nm and a Ti film having a high anticorrosive effect: 10 to 20 nm in this order as a protective film. For the purpose of reducing contact resistance between the n layer and the back electrode layer 4 and improving light reflection, a GZO (Ga-doped ZnO film) film thickness between the photoelectric conversion layer 3 and the back electrode layer 4 is 50 to 100 nm, a sputtering apparatus. May be provided by forming a film.
(7) FIG. 6 (b)
The substrate 1 is placed on an XY table, and the second harmonic (532 nm) of the laser diode-pumped YAG laser is incident from the substrate 1 side as shown by the arrow in the figure, so that the laser light is converted into a photoelectric conversion layer. The back electrode layer 4 is exploded and removed by utilizing the high gas vapor pressure generated at this time. Pulse oscillation: 1 to 10 kHz, the laser power is adjusted so as to be suitable for the processing speed, and laser etching is performed so that the groove 12 is formed on the lateral side of the laser etching line of the transparent conductive layer 2 of about 250 μm to 400 μm. .
(8) FIG. 6 (c)
The power generation region is divided to eliminate the influence that the serial connection portion due to laser etching is likely to be short-circuited at the film edge around the substrate edge. The substrate 1 is placed on an XY table, and the second harmonic (532 nm) of the laser diode pumped YAG laser is incident from the substrate 1 side, so that the laser light is absorbed by the transparent conductive layer 2 and the photoelectric conversion layer 3. Then, using the high gas vapor pressure generated at this time, the back electrode layer 4 is exploded and removed. The laser power is adjusted so that the processing speed is appropriate for pulse oscillation: 1 to 10 kHz, and laser etching is performed so that the X-direction insulating groove 15 is formed at a position of 5 to 15 mm from the end of the substrate 1. At this time, no Y-direction insulating groove is provided.
The groove 11 terminates the etching at a position of 5 to 10 mm from the end of the substrate 1. The etching may be terminated by stopping the laser beam, but can be dealt with simply by installing a metallic masking plate in the non-laser etching region of the substrate 1. By terminating the etching at a position of 5 to 10 mm from the end of the substrate 1, an effective effect is exerted in suppressing external moisture intrusion into the solar cell module 6 from the end of the solar cell panel.
(9) FIG. 7 (a)
In order to secure a healthy adhesion surface with the back sheet through EVA or the like in a later process, the laminated film around the substrate 1 (the surrounding region 14) has a step and is easy to peel off, so this film is removed. First, in the back electrode layer 4 / photoelectric conversion layer 3 / transparent conductive layer 2 on the substrate end side with respect to the insulating groove 15 provided in the step of FIG. Is performed by grinding a rotating grindstone. In the initial stage, all of the back electrode layer 4, the photoelectric conversion layer 3, and a part of the transparent conductive layer 2, which occupy 50% or more of the total laminated film thickness of the solar battery power generation cell 5, are shaved by polishing with a rotating grindstone. After the rough cutting is completed, the remaining portion is polished and removed by blast polishing. Next, even with scratches and grooves remaining by finishing polishing (hairline treatment) using a rotating grindstone made of # 800 silicon carbide-based abrasive having a width of 3 to 5 mm, it extends across the peripheral region 14 to the solar cell module 6 side. Process to cut the groove. Polishing debris and abrasive grains were removed by cleaning the substrate 1.
(10) FIG. 7 (b)
At the terminal box mounting part, an opening through window is provided in the back sheet and the current collector plate is taken out. A plurality of layers of insulating materials are installed in the opening through window portion to suppress intrusion of moisture and the like from the outside.
Processing so that power can be taken out from the terminal box portion on the back side of the solar cell panel by collecting copper foil from the one end solar cell 5 and the other end solar cell 5 in series. To do. In order to prevent a short circuit with each part, the copper foil arranges an insulating sheet wider than the copper foil width.
After the current collecting copper foil or the like is disposed at a predetermined position, a filler sheet made of EVA (ethylene vinyl acetate copolymer) or the like is disposed so as to cover the entire solar cell module 6 and not protrude from the substrate 1.
A back sheet having a high waterproofing effect is installed on the EVA. In this embodiment, the back sheet has a three-layer structure of PTE sheet / AL foil / PET sheet so that the waterproof and moisture proof effect is high.
The EVA is cross-linked and closely adhered while the inside of the back sheet at a predetermined position is deaerated with a laminator in a reduced pressure atmosphere and pressed at about 150 to 160 ° C.
(11) FIG. 8 (a)
A terminal box is attached to the back side of the solar cell module 6 with an adhesive.
(12) FIG. 8 (b)
The copper foil and the output cable of the terminal box are connected with solder or the like, and the inside of the terminal box is filled with a sealing agent (potting agent) and sealed. This completes the solar cell panel.
(13) FIG. 8 (c)
About the solar cell panel formed in the steps up to FIG. 8 (b) in order to compare with the solar cell panel (FIG. 10) according to the conventional process having insulating grooves in the circumferential direction of the solar cell panel in the X and Y directions. Conduct power generation inspections and predetermined performance tests. The power generation inspection is performed using a solar simulator of AM1.5 and solar radiation standard sunlight (1000 W / m ² ).
(14) FIG. 8 (d)
A predetermined performance test is performed before and after the power generation inspection (FIG. 8C).
(I) Insulation inspection A DC: 1000V load is applied between the output terminal of the laminated solar cell panel and the conductive portion such as the substrate end face and the back sheet to confirm that the resistance value ≧ 100 MΩ.
(Ii) Dielectric strength test DC: 3800V (or 2200V) was applied for 1 minute between the output terminal of the laminated solar cell panel and the conductive part such as the substrate end face or back sheet to confirm that there was no dielectric breakdown. To do.
(Iii) High-temperature and high-humidity test The final confirmation that the structure and manufacturing conditions are appropriate due to the change in the manufacturing method was carried out by simulating outdoor harsh conditions and by exposing to light for 20 hours in accordance with JISC8938. After stabilizing the performance in advance, it is confirmed that there is no change in performance under high temperature and high humidity conditions: temperature 85 ° C., humidity: 85%, evaluation time 1000 hours. (Verify that there is no change in appearance and that 95% or more of the initial performance value is secured and that there is no change in performance.

  By the said manufacturing method, the solar cell panel used as the product using this invention was manufactured, and it confirmed that the characteristic was not different from the thing by the conventional process. In the long-term reliability confirmation test in the high-temperature and high-humidity test, it was confirmed that the appearance was not changed even when the evaluation time was further extended, and the reliability was improved over the conventional process.

  In the present invention, since both ends of the groove 10 are provided in front of both sides of the substrate 1 (the first side 1a and the second side 1b), there is a risk that external moisture may enter the solar cell 5 from the groove 10. Disappears. And it can prevent that the deterioration of the photovoltaic power generation cell 5 by the moisture permeation from a crack or a groove | channel generate | occur | produces. That is, it is possible to appropriately perform the groove processing step of the solar cell module so as to further improve the long-term reliability.

  In the present invention, the X-direction insulating groove 15 is provided but the Y-direction insulating groove is not provided, so that the groove processing process can be shortened and the processing time can be shortened. From the experiments of the present inventors, it has been found that the characteristics of the solar cell module are not changed at all in this case. That is, without reducing the performance of the solar cell module, it is possible to shorten the processing time required for the step of groove processing of the end portion of the solar cell module and improve productivity.

  In the present invention, since both ends of the groove 10 are provided so as not to reach both sides (the first side 1a and the second side 1b) of the substrate 1, there is no possibility that external moisture enters the solar cell 5 from the groove 10. . Then, it is possible to prevent the deterioration of the solar battery power generation cell 5 due to moisture intrusion from the groove. That is, it is possible to appropriately perform the groove processing step of the solar cell module so as to further improve the long-term reliability.

  In the present invention, since both ends of the X-direction insulating groove 15 are provided so as not to reach both sides (the third side 1c and the fourth side 1d) of the substrate 1, external moisture is supplied from the X-direction insulating groove 15 to the photovoltaic power generation cell 5. There is no risk of intrusion. Then, it is possible to prevent the deterioration of the solar battery power generation cell 5 due to moisture intrusion from the groove. That is, it is possible to appropriately perform the groove processing step of the solar cell module so as to further improve the long-term reliability.

  In the present invention, since the peripheral region 14 is polished by different methods divided into the above three steps, the film in the peripheral region 14 is reliably removed while leaving no scratches or grooves in the peripheral region 14. be able to. Thereby, it becomes possible to perform the grinding | polishing of the surrounding area | region of a solar cell module appropriately, without reducing long-term reliability.

  Although the said embodiment demonstrated what used the amorphous silicon thin film solar cell as the photoelectric converting layer 3, this invention is a microcrystalline silicon solar cell, and an amorphous silicon solar cell and a microcrystalline silicon solar cell 1 to plural each. The present invention can be similarly applied to other types of thin film solar cells such as tandem solar cells stacked in layers. Furthermore, the present invention provides a solar cell of a type in which a back electrode (referred to as a back surface in the opposite sense of light incidence) is formed on a metal substrate or the like, and a photoelectric conversion layer and a light incident side transparent conductive layer are formed thereon. Can be applied similarly.

DESCRIPTION OF SYMBOLS 1 Board | substrate 1a 1st edge | side 1b 2nd edge | side 1c 3rd edge | side 1d 4th edge | side 2 Transparent conductive layer 3 Photoelectric conversion layer 4 Back surface electrode layer 5 Solar cell power generation cell 6 Solar cell module 10, 11, 12 Groove | channel 14 Surrounding area | region 15, 15a, 15b X direction insulating groove 21 Polishing direction 101 Substrate 102 Transparent conductive layer 103 Photoelectric conversion layer 104 Back electrode layer 105 Solar cell power generation cell 106 Solar cell module 110, 111, 112 Groove 113 Y direction insulating groove 114 Surrounding region 115 X direction Insulation groove

Claims (4)

A translucent light having a first side, a second side facing the first side, a third side between the first side and the second side, and a fourth side facing the third side Sex substrate,
A plurality of power generation cells provided on the substrate, extending along the third side and arranged along the first side, and connected in series with each other;
The plurality of power generation cells in the peripheral portion of the substrate are removed to expose the substrate, and the surface on which the substrate is exposed is an adhesive surface of a sheet material that seals the plurality of power generation cells,
Each of the plurality of power generation cells is
A transparent conductive layer, a photoelectric conversion layer, and a back electrode layer are included on the substrate in this order,
An insulating groove extending from the back electrode layer, which is the surface of the plurality of power generation cells, to the surface of the substrate, the first groove being an insulating groove along the first side in the vicinity of the first side; A second groove that is an insulating groove along the second side in the vicinity of the second side, the groove along the third side in the vicinity of the third side, and the fourth in the vicinity of the fourth side. There is no insulation groove along the side,
The solar cell panel, wherein the first groove and the second groove extend to the vicinity of the third side and the fourth side so as not to reach an end of the substrate. The solar cell panel according to claim 1,
The ends of the first groove and the second groove are solar cell panels that are separated from the edge of the substrate by a distance of 5 mm to 10 mm. In the solar cell panel according to claim 1 or 2,
The plurality of power generation cells includes a first film formed on the substrate,
The first film has a third groove extending in a direction different from the direction of the first side and the second side,
The third groove extends from the surface of the first film to the surface of the substrate and extends to the vicinity of the first side and the second side so as not to reach the end of the substrate. In the solar cell panel according to claim 3,
The end of the third groove is a solar cell panel separated from the end of the substrate by a distance of 5 mm or more and 10 mm or less.

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