Photovoltaic module and interconnector

Abstract

To provide a photovoltaic module and an interconnector that suppress the possibility of defective electrical connection between a first photovoltaic cell and a second photovoltaic cell when a spacing between the first and second photovoltaic cells adjacent to each other changes and that has improved durability.SOLUTION: A photovoltaic module has an interconnector. The interconnector includes: a first interconnector including a first electrode connected to a first busbar electrode of a first photovoltaic cell, a second electrode connected to a fourth busbar electrode of a second photovoltaic cell, and a first connector connecting the first electrode and the second electrode; and a second interconnector including a third electrode connected to a second busbar electrode of the first photovoltaic cell, a fourth electrode connected to a third busbar electrode of the second photovoltaic cell, and a second connector connecting the third electrode and the fourth electrode. Therein the first connector includes: a first expanding and contracting portion that is expandable and contractible; and the second connector has a second expanding and contracting portion that is expandable and contractible.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to solar cell modules and interconnectors. [Background technology]

[0002] A solar cell module is a device that can generate a predetermined amount of power when irradiated with sunlight. Such solar cell modules are used, for example, in solar panels mounted on the bodies of passenger cars.

[0003] Patent Document 1 discloses a solar panel provided with an interconnector. The interconnector includes a first electrode connected to a first solar cell, a second electrode connected to a second solar cell, and a connector connecting the first electrode and the second electrode. The connector has a one-side first detour portion as the first detour portion, a one-side second detour portion as the second detour portion, and a first connection portion as the connection portion. The one-side first detour portion has a first curved portion where the end on the first electrode side curves toward the end opposite the second electrode and connects to the first electrode.

[0004] In this type of solar panel, expansion and contraction can occur due to temperature changes during manufacturing and use, which causes changes in the distance between adjacent first and second solar cells. The technology described in Patent Document 1 makes the shape of the interconnector round or curved, thereby absorbing changes in the distance between the first and second solar cells when the solar cell module expands and contracts due to temperature changes, and suppressing breakage of the interconnector. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-26380 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, in order to improve power generation efficiency and prevent a decrease in power generation due to cracks in solar cell cells, solar cell modules have adopted a multi-wire system in which multiple bus bar electrodes are provided on the solar cell.

[0007] Therefore, it is conceivable to enable electrical conduction between a plurality of busbar electrodes provided on a first solar cell and a plurality of busbar electrodes provided on a second solar cell that are adjacent to each other and spaced apart in the first direction, using a plurality of interconnectors as described in Patent Document 1. On the other hand, the more the number of busbar electrodes provided on the first and second solar cells increases, the more it is necessary to reduce the size of each interconnector (specifically, the size in a second direction that is approximately perpendicular to the first direction).

[0008] Therefore, when the interconnector described in Patent Document 1 is applied to a solar cell module that employs a multi-wire system, stress tends to concentrate on the portion of the interconnector with a small curvature when the distance between the first solar cell and the second solar cell changes. As a result, the technology described in Patent Document 1 has a problem in that the interconnector may break, making it impossible to properly conduct electricity between the first solar cell and the second solar cell.

[0009] The present disclosure has been made to solve such problems, and aims to provide a solar cell module and interconnector that suppresses poor electrical conductivity between a first solar cell and a second solar cell when the distance between adjacent first solar cell and second solar cell changes, and has improved durability. [Means for solving the problem]

[0010] A solar cell module according to one embodiment includes a first solar cell, a second solar cell adjacent to the first solar cell at an interval in a first direction, and an interconnector that allows electrical conduction between the first solar cell and the second solar cell, wherein the first solar cell has a first bus bar electrode and a second bus bar electrode adjacent to the first solar cell at an interval in a second direction that is substantially perpendicular to the first direction, and the second solar cell has a third bus bar electrode adjacent to the second solar cell at an interval in the second direction and arranged substantially linearly with the first bus bar electrode along the first direction, and a fourth bus bar electrode adjacent to the second bus bar electrode along the first direction. The interconnector has a first interconnector including a first electrode connected to the first bus bar electrode, a second electrode connected to the fourth bus bar electrode, and a first connector connecting the first electrode and the second electrode, and a second interconnector including a third electrode connected to the second bus bar electrode, a fourth electrode connected to the third bus bar electrode, and a second connector connecting the third electrode and the fourth electrode, wherein the first connector has a first extensible portion that can expand and contract in a direction connecting the first electrode and the second electrode, and the second connector has a second extensible portion that can expand and contract in a direction connecting the third electrode and the second electrode. [Effects of the Invention]

[0011] The present disclosure makes it possible to provide a solar cell module and interconnector that suppresses poor electrical conductivity between the first solar cell and the second solar cell when the distance between adjacent first solar cell and second solar cell changes, and has improved durability. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a part of a solar cell module according to a first embodiment. [Figure 2] 1 is a perspective view showing a part of a solar cell module according to a first embodiment. [Figure 3] 5A and 5B are diagrams illustrating dimensional changes in the interconnector that occur when the solar cell module according to the first embodiment expands due to a temperature change. [Figure 4]5A and 5B are diagrams illustrating changes in the interconnector that occur when the solar cell module according to the first embodiment expands due to a temperature change. [Figure 5] FIG. 10 is a perspective view showing a part of a solar cell module according to a comparative example. [Figure 6] 10A and 10B are diagrams illustrating deformation of an interconnector that occurs when a solar cell module according to a comparative example expands due to a temperature change. DETAILED DESCRIPTION OF THE INVENTION

[0013] Embodiment 1 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiments. Furthermore, for clarity of explanation, the following description and drawings have been simplified as appropriate. What is shown in the drawings is only a part of the whole, and in reality, many other configurations not shown are included. In the following description, the same or equivalent elements are given the same reference numerals, and redundant explanations will be omitted.

[0014] Fig. 1 is a cross-sectional view showing a part of a solar cell module according to embodiment 1. The solar cell module 1 shown in Fig. 1 is a device that is mounted on the body of a passenger car, for example, and converts sunlight into electricity. Note that the solar cell module 1 is not limited to being mounted on the body of a car, and may also be disposed on a building or facility.

[0015] In this embodiment, the left-right direction of the solar cell module 1 and the up-down direction, which is the thickness direction of the solar cell module 1, are defined by the arrow directions shown in FIG. 1. The left-right direction and the up-down direction are perpendicular to each other. In FIG. 2 and other figures, the directions of the solar cell module 1 are defined corresponding to FIG. 1, and the front-rear direction of the solar cell module 1 is also defined. The front-rear direction is perpendicular to both the left-right direction and the up-down direction. The left-right direction of the solar cell module 1 is a specific example of a first direction. In the following description, the left direction corresponds to one side of the first direction, and the right direction corresponds to the other side of the first direction. The front-rear direction of the solar cell module 1 is a specific example of a second direction. In the following description, the rear direction corresponds to one side of the second direction, and the front direction corresponds to the other side of the second direction. Note that these directions are merely examples for the sake of convenience, and are not related to the directions of the solar cell module 1 when in use.

[0016] 1, the solar cell module 1 has a first solar cell 2, a second solar cell 3, an interconnector 4, a sealing material 5, a front surface member 6, and a back surface member 7. This solar cell module 1 has a structure in which the first solar cell 2 and the second solar cell 3, which are connected by a plurality of interconnectors 4, are provided between the front surface member 6 and the back surface member 7, and are sealed with the sealing material 5.

[0017] The first solar cell 2 is located on the left side, which is one side in the first direction. The second solar cell 3 is located on the right side, which is the other side in the first direction. The second solar cell 3 is adjacent to the first solar cell 2 with a gap in the left-right direction, which is the first direction. The gap between the first solar cell 2 and the second solar cell 3, which are connected by multiple interconnectors 4, is, for example, 6 mm. The gap between the first solar cell 2 and the second solar cell 3 can be changed as appropriate depending on the specifications of the solar cell module 1. In the following description, the gap between the first solar cell 2 and the second solar cell 3 may be referred to as the "cell gap."

[0018] The first and second solar cells 2, 3 have the same configuration and exhibit the same performance. The first solar cell 2 has a first semiconductor substrate 21. The first semiconductor substrate 21 includes a first substrate front surface 22 and a first substrate back surface 23 located opposite the first substrate front surface 22. The second solar cell 3 has a second semiconductor substrate 31. The second semiconductor substrate 31 includes a second substrate front surface 32 and a second substrate back surface 33 located opposite the second substrate front surface 32. The first and second semiconductor substrates 21, 31 may be made of, for example, a single-crystal or polycrystalline crystalline silicon semiconductor. Note that, crystalline semiconductors other than crystalline silicon may also be used for the first and second semiconductor substrates 21, 31. The first substrate front surfaces 22, 32 are surfaces facing upward. The first and second substrate back surfaces 23, 33 are surfaces facing downward.

[0019] The first and second solar cells 2, 3 are, for example, double-sided electrode type (also called double-sided junction type) solar cells. The first solar cell 2 has a front surface electrode 24 and a back surface electrode 25. The second solar cell 3 has a front surface electrode 34 and a back surface electrode 35. In the first solar cell 2, the front surface electrode 24 and the back surface electrode 25 are provided so as to face each other on their front and back surfaces. In the second solar cell 3, the front surface electrode 34 and the back surface electrode 35 are provided so as to face each other on their front and back surfaces. FIG. 1 shows first bus bar electrodes 241, 341 included in each of the front surface electrodes 24, 34, and third bus bar electrodes 251, 351 included in each of the back surface electrodes 25, 35.

[0020] The interconnector 4 is a wiring material that allows electricity to flow between the first solar cell 2 and the second solar cell 3. The interconnector 4 has a first interconnector 41 and a second interconnector 42. The first and second interconnectors 41, 42 have a flat plate shape that is horizontal to the first and second solar cell 2, 3.

[0021] The first interconnector 41 is located below the surface electrode 24 and the first semiconductor substrate 21. The second interconnector 42 is located below the surface electrode 34 and the second semiconductor substrate 31. Furthermore, the second interconnector 42 is arranged adjacent to the first interconnector 41 with a gap therebetween in the vertical direction so as not to interfere with the first interconnector 41. The second interconnector 42 is located, for example, above the first interconnector. Note that the vertical positional relationship between the first and second interconnectors is not limited to this, and the second interconnector 42 may be located below the first interconnector 41.

[0022] The sealing material 5 fixes the first solar cell 2, the second solar cell 3, and the interconnector 4 in a sealed state between the front surface member 6 and the back surface member 7. The sealing material 5 protects the first and second solar cells 2, 3 by sealing them. The sealing material 5 is made of a light-transmitting resin. For example, ethylene vinyl acetate copolymer (EVA) can be used as the resin for forming the sealing material 5. Note that the resin for forming the sealing material 5 is not limited to EVA, and polyolefin resin, ionomer resin, silicone resin, etc. may also be used.

[0023] The surface member 6 is a plate-like or film-like member that protects the first and second solar cells 2 and 3 together with the sealing material 5. The surface member 6 is provided on the first and second substrate surfaces 22 and 32 side of the sealing material 5. The surface member 6 is a light-transmitting member that has an incident surface 61 on which sunlight enters and an exit surface 62 on the opposite side of the incident surface 61.

[0024] The incident surface 61 and the exit surface 62 are, for example, flat surfaces. Note that the incident surface 61 and the exit surface 62 are not limited to being flat surfaces and may be curved surfaces. The incident surface 61 is, for example, arranged horizontally. The exit surface 62 is arranged so as to be approximately parallel to the incident surface 61. The first and second solar cells 2 and 3 are arranged so as to face the exit surface 62. That is, the first and second solar cells 2 and 3 are arranged along the exit surface 62. The exit surface 62 faces the first and second substrate surfaces 22 and 32. The first and second substrate surfaces 22 and 32 are arranged so as to be approximately parallel to the exit surface 62, for example. Sunlight incident on the incident surface 61 passes through the surface member 6, exits from the exit surface 62, passes through the sealing material 5, and is incident on the first and second substrate surfaces 22 and 32.

[0025] The rear surface member 7 is a plate-like member that protects the first and second solar cells 2 and 3 together with the sealing material 5. The rear surface member 7 is provided on the rear surfaces 23 and 33 of the first and second substrates with respect to the sealing material 5. The rear surface member 7 is also called a back plate. The rear surface member 7 has a front surface 71 that faces the front surface member 6, the first and second solar cells, and the sealing material 5, and a rear surface 72 located opposite the front surface 71.

[0026] The first and second solar cells 2 and 3 are arranged to face the front surface 71. That is, the first and second solar cells 2 and 3 are arranged along the front surface 71. The back surface 72 is arranged to be approximately parallel to the front surface 71, for example.

[0027] The front surface member 6 and the back surface member 7 are preferably made of a light-transmitting resin such as polycarbonate resin or acrylic resin. By making the front surface member 6 and the back surface member 7 from a light-transmitting resin, the weight of the solar cell module 1 can be reduced compared to when the front surface member 6 and the back surface member 7 are made of glass, for example.

[0028] However, the front surface member 6 is not limited to polycarbonate resin or acrylic resin, and may be formed from other light-transmitting resins such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or glass. The back surface member 7 is not limited to polycarbonate resin or acrylic resin, and may be formed from resins such as PET or PEN, or metals such as steel (e.g., S45C) or aluminum alloy. When the back surface member 7 is formed from resin, the resin may contain fibers or fillers to increase rigidity. Furthermore, the thicknesses of the front surface member 6 and the back surface member 7 can be changed as appropriate.

[0029] Next, Fig. 2 is a perspective view showing a part of the solar cell module according to the first embodiment. Fig. 2 shows a first solar cell 2 and a second solar cell 3 connected by an interconnector 4. An enlarged view of a part of the solar cell 2 and the second solar cell 3 is shown within the dashed dotted line in Fig. 2. The first solar cell 2, the second solar cell 3, and the interconnector 4 will be described in more detail with reference to Fig. 2.

[0030] As shown in Figure 2, the first and second solar cell 2, 3 are divided cells obtained by dividing a standard-sized cell (also called a full cell). Examples of divided cells include a standard-sized cell divided in half (a half cell). Divided cells can reduce the current value per cell (by half in the case of a half cell), which makes it possible to reduce power loss in the solar cell module 1. Furthermore, because divided cells can be connected in series more frequently than standard-sized cells, the voltage can be increased.

[0031] In this embodiment, the first and second solar cells 2, 3 are half cells obtained by dividing a cell having a size of approximately 182 mm square into two, and therefore have a length of 182 mm and a width of 91 mm. Also, although Figs. 1 and 2 show the first solar cell 2 and the second solar cell 3, which are two solar cells adjacent in the left-right direction, the number of solar cells included in the solar cell module 1 is not limited to two. The size and number of the first and second solar cell 2, 3 can be changed as appropriate depending on the size of the solar cell module 1, etc.

[0032] The first and second solar cells 2 and 3 have a generally rectangular flat plate shape. The shape of the first and second solar cells 2 and 3 is not limited to a generally rectangular flat plate shape, and may be a generally square or other polygonal flat plate shape. Furthermore, the shape of the first and second solar cells 2 and 3 is not limited to a flat plate shape.

[0033] The surface electrodes 24, 34 provided on the first and second substrate surfaces 22, 32 include five first bus bar electrodes 241, 341 and five second bus bar electrodes 242, 342, for a total of ten bus bar electrodes, and the first bus bar electrodes 241, 341 and the second bus bar electrodes 242, 342 are arranged alternately adjacent to each other at intervals in the front-rear direction, which is the second direction. The back surface electrodes 25, 35 provided on the first and second substrate back surfaces 23, 33 include five third bus bar electrodes 251, 351 and five fourth bus bar electrodes 252, 352, for a total of ten bus bar electrodes, and the third bus bar electrodes 251, 351 and the fourth bus bar electrodes 252, 352 are arranged alternately adjacent to each other at intervals in the front-rear direction. It is sufficient that there are one or more combinations of the first bus bar electrodes 241, 341 and the second bus bar electrodes 242, 342, and there is also sufficient that there are one or more combinations of the third bus bar electrodes 251, 351 and the fourth bus bar electrodes 252, 352. The numbers of the first to fourth bus bar electrodes 241 to 352 can be changed as appropriate depending on the areas of the first and second solar cells 2, 3, etc.

[0034] In each of the first and second solar cells 2 and 3, the first bus bar electrodes 241 and 341 and the third bus bar electrodes 251 and 351 are arranged facing each other, and the second bus bar electrodes 242 and 342 and the fourth bus bar electrodes 252 and 352 are arranged facing each other. The distance between the first bus bar electrodes 241 and 341 and the second bus bar electrodes 242 and 342 adjacent to each other in the front-to-rear direction is, for example, 17.3 mm. In this embodiment, the distance between the third bus bar electrodes 251 and 351 and the fourth bus bar electrodes 252 and 352 adjacent to each other in the front-to-rear direction is also, for example, 17.3 mm. The distance between these bus bar electrodes can be changed as appropriate depending on the specifications of the first and second solar cells 2 and 3.

[0035] The third bus bar electrode 351 formed on the second substrate rear surface 33 is aligned approximately linearly in the left-right direction with the first bus bar electrode 241 formed on the first substrate front surface 22. The fourth bus bar electrode 352 formed on the second substrate rear surface 33 is aligned approximately linearly in the left-right direction with the second bus bar electrode 242 formed on the first substrate front surface 22. The third bus bar electrode 251 formed on the first substrate rear surface 23 is aligned approximately linearly in the left-right direction with the first bus bar electrode 341 formed on the second substrate front surface 32. The fourth bus bar electrode 252 formed on the first substrate rear surface 23 is aligned approximately linearly in the left-right direction with the second bus bar electrode 342 formed on the second substrate front surface 32.

[0036] The first to fourth bus bar electrodes 241 to 352 have, for example, a substantially circular cross section cut in the front-rear direction. The diameter of the cross section of the first to fourth bus bar electrodes 241 to 352 is, for example, 0.3 mm. The first to fourth bus bar electrodes 241 to 352 are formed, for example, from a copper alloy. The first to fourth bus bar electrodes 241 to 352 may be formed from copper, or may be formed from a metal other than copper or a copper alloy. The cross-sectional shape and diameter of the first to fourth bus bar electrodes 241 to 352 can be changed as appropriate depending on the magnitude of the current flowing through them.

[0037] The first and second bus bar electrodes 241, 242 each have a first base portion 24a and a first protruding end portion 24b. Here, with reference to Fig. 1, the first base portion 24a and the first protruding end portion 24b included in the first solar cell 2 will be specifically described in detail.

[0038] 1, at least a portion of the first base portion 24a is in contact with the first substrate surface 22. The first base portion 24a extends linearly in the left-right direction while in contact with the first substrate surface 22 from one end side to the other end side.

[0039] The first protruding end 24b is located on the right side in the left-right direction, that is, on the side of the second solar cell 3. The first protruding end 24b protrudes from the first semiconductor substrate 21 towards the second solar cell 3. The first protruding end 24b extends in a downwardly bending manner from the other end of the first base portion 24a.

[0040] The third and fourth bus bar electrodes 251, 252 each have a second base portion 25a and a second protruding end portion 25b. Here, with reference to Fig. 1, the second base portion 25a and the second protruding end portion 25b included in the second solar cell 3 will be specifically described in detail.

[0041] As shown in FIG. 1 , at least a portion of second base portion 25a is in contact with second substrate back surface 33. One end of second base portion 25a extends linearly in the left-right direction while in contact with second substrate back surface 33, and then the other end bends downward to gradually move away from second substrate back surface 33. Second protruding end portion 25b is located on the left side in the left-right direction, toward first solar cell 2. Second protruding end portion 25b protrudes from second semiconductor substrate 31 toward first solar cell 2. Second protruding end portion 25b extends from the other end of second base portion 25a in an upward bent manner.

[0042] Furthermore, the surface electrodes 24, 34 are adjacent to each other in the left-right direction and have a plurality of finger electrodes (not shown) extending in the front-rear direction to connect the first bus bar electrodes 241, 341 and the second bus bar electrodes 242, 342. Each bus bar electrode (first, second, third, and fourth bus bar electrodes) and finger electrodes can be formed by a printing method such as screen printing using a thermosetting conductive paste containing conductive particles such as copper particles and a binder such as resin.

[0043] 2, in this solar cell module 1, nine interconnectors 4 are connected to form an interconnector group 40 extending in the front-to-rear direction. Note that the number of interconnectors 4 that form the interconnector group 40 can be changed as appropriate depending on the number of bus bar electrodes, etc.

[0044] The interconnector 4 is made of, for example, a Cu-Ni-P alloy. By using a Cu-Ni-P alloy that has high strength and high conductivity, it is possible to easily form the elastically deformable first and second connectors 413, 423 described below. A specific example of a Cu-Ni-P alloy is KLF170 (registered trademark). The interconnector 4 may be made of copper, or may be made of a copper alloy other than a Cu-Ni-P alloy, or may be made of a metal other than copper or a copper alloy.

[0045] The interconnector group 40, i.e., the nine first interconnectors 41 included in the nine interconnectors 4, are integrally formed by stamping a copper plate. The interconnector group 40, i.e., the nine second interconnectors 42 included in the nine interconnectors 4, are also integrally formed by stamping a copper plate. The first and second interconnectors 42 may be formed using a metal plate other than a copper plate.

[0046] The first interconnector 41 includes a first electrode 411, a second electrode 412, and a first connector 413. The first electrode 411 is connected to the first bus bar electrode 241. The first electrode 411 is located on the front and left end side of the interconnector 4. The first electrode 411 has a substantially circular shape when viewed from the top-bottom direction. The first electrode 411 has a right edge 4111 located on the right side.

[0047] A first insertion hole 411a is formed in the first electrode 411. The first insertion hole 411a penetrates in the up-down direction. The first insertion hole 411a is formed, for example, in approximately the center of the first electrode 411. The first protruding end portion 24b of the first busbar electrode 241 is inserted into the first insertion hole 411a from above. The first protruding end portion 24b inserted into the first insertion hole 411a is joined to the first electrode 411 by a joining method such as soldering.

[0048] The second electrode 412 is connected to the fourth bus bar electrode 252. The second electrode 412 is located on the rear end side and the right end side of the interconnector 4. The second electrode 412 has a substantially circular shape when viewed from the top-bottom direction. The second electrode 412 has a left edge 4121 located on the left side.

[0049] A second insertion hole 412a is formed in the second electrode 412. The second insertion hole 412a penetrates in the up-down direction. The second insertion hole 412a is formed, for example, in approximately the center of the second electrode 412. The second protruding end portion 25b of the fourth bus bar electrode 252 is inserted into the second insertion hole 412a from below. The second protruding end portion 25b inserted into the second insertion hole 412a is joined to the second electrode 412 by a joining method such as soldering.

[0050] The first connector 413 connects the first electrode 411 and the second electrode 412. The first connector 413 extends in the front-rear direction so as to connect the first electrode 411 and the second electrode 412. In the first interconnector 41, the first electrode 411 and the second electrode 412 can be electrically connected to each other through the first connector 413.

[0051] The first connecting body 413 has a first stretchable portion 4131 located on the inside in the front-to-back direction, a rear end portion 4132 located on the rear side, which is one side in the second direction, a front end portion 4133 located on the front side, which is the other side in the second direction, a left edge 4134 located on the left side in the left-to-right direction, and a right edge 4135 located on the right side.

[0052] The first stretchable portion 4131 is sandwiched between the rear end portion 4132 and the front end portion 4133. When viewed from the top and bottom, the first stretchable portion 4131 is formed in a crank-like meandering line. The first stretchable portion 4131 is stretchable in a direction connecting the first electrode 411 and the second electrode 412.

[0053] The rear end portion 4132 connects to the first electrode 411 while curving from the front side to the right, which is the side of the second solar cell 3. Specifically, as the rear end portion 4132 approaches the first electrode 411 from the front side, the right edge 4135 curves to the right and connects to the right edge 4111 of the first electrode 411. This allows the first connector 413 to be connected to the first electrode 411 smoothly.

[0054] The front end portion 4133 connects to the second electrode 412 from the rear side while curving to the left, which is the side of the first solar cell 2. Specifically, as the front end portion 4133 approaches the second electrode 412 from the rear side, the left edge 4134 curves to the left and connects to the left edge 4121 of the second electrode 412. This allows the first connector 413 to be connected to the second electrode 412 smoothly.

[0055] In the first interconnector 41, the first connecting body 413 is connected smoothly to the first and second electrodes 412, which makes it possible to suitably distribute the stress that occurs in the rear end portion 4132 and the front end portion 4133 (particularly the right end edge 4135 of the rear end portion 4132 and the left end edge 4134 of the front end portion 4133) when the first expandable portion 4131 of the first connecting body 413 is deformed. This makes it difficult for the first connecting body 413 to break. Here, the curvature of each of the rear end portion 4132 and the front end portion 4133 is smaller than that of other parts of the first interconnector 41.

[0056] As described above, in the solar cell module 1, the first interconnector 41 connects the first bus bar electrode 241 and the fourth bus bar electrode 252, and electricity can be conducted between the first bus bar electrode 241 and the fourth bus bar electrode 252 through the first interconnector 41.

[0057] The second interconnector 42 has a shape symmetrical to the first interconnector 41 in the left-right direction. The second interconnector 42 includes a third electrode 421, a fourth electrode 422, and a second connector 423. The third electrode 421 is connected to the third bus bar electrode 251. The third electrode 421 is located on the rear end side and the right end side of the interconnector 4. The third electrode 421 has a substantially circular shape when viewed from the top-bottom direction. The third electrode 421 has a left edge 4211 located on the left side.

[0058] A third insertion hole 421a is formed in the third electrode 421. The third insertion hole 421a penetrates in the up-down direction. The third insertion hole 421a is formed, for example, in approximately the center of the third electrode 421. The second protruding end portion 25b of the third bus bar electrode 251 is inserted into the third insertion hole 421a from below. The second protruding end portion 25b inserted into the third insertion hole 421a is joined to the third electrode 421 by a joining method such as soldering.

[0059] The fourth electrode 422 is connected to the second bus bar electrode 242. The fourth electrode 422 is located on the front and left end side of the interconnector 4. The fourth electrode 422 has a substantially circular shape when viewed from the top and bottom. The fourth electrode 422 has a right edge 4221 located on the right side.

[0060] A fourth insertion hole 422a is formed in the fourth electrode 422. The fourth insertion hole 422a penetrates in the up-down direction. The fourth insertion hole 422a is formed, for example, in approximately the center of the fourth electrode 422. The first protruding end portion 24b of the second bus bar electrode 242 is inserted into the fourth insertion hole 422a from above. The first protruding end portion 24b inserted into the fourth insertion hole 422a is joined to the fourth electrode 422 by a joining method such as soldering.

[0061] The second connector 423 connects the third electrode 421 and the fourth electrode 422. The second connector 423 extends in the front-rear direction so as to connect the third electrode 421 and the fourth electrode 422. In the second interconnector 42, electricity can be conducted between the third electrode 421 and the fourth electrode 422 through the second connector 423.

[0062] The second connecting body 423 has a second stretchable portion 4231 located on the inside in the front-to-rear direction, a rear end portion 4232 located on the rear side in the front-to-rear direction, a front end portion 4233 located on the front side, a left edge 4234 located on the left side in the left-to-right direction, and a right edge 4235 located on the right side.

[0063] The second stretchable portion 4231 is sandwiched between the rear end portion 4232 and the front end portion 4233. When viewed from the top-bottom direction, the second stretchable portion 4231 is formed in a crank-like meandering line shape. The second stretchable portion 4231 is elastically deformable in the left-right direction and the front-back direction.

[0064] The rear end portion 4132 connects to the third electrode 421 while curving from the front side to the left, which is the side of the first solar cell 2. Specifically, as the rear end portion 4132 approaches the third electrode 421 from the front side, the left edge of the rear end portion 4132 curves to the left and connects to the left edge of the third electrode 421. This allows the second connector 423 to be connected to the third electrode 421 in a smooth manner.

[0065] The front end portion 4233 connects to the fourth electrode 422 while curving from the rear side to the right, which is the second solar cell 3 side. Specifically, the right edge of the front end portion 4233 curves to the right as it approaches the fourth electrode 422 from the rear side in the front-to-rear direction, and connects to the right edge of the fourth electrode 422. In this way, the second connector 423 is connected to the fourth electrode 422 in a smooth manner.

[0066] In the second interconnector 42, the second connecting body 423 is connected to the third and fourth electrodes 422 smoothly, and this allows the stress generated in the rear end portion 4232 and the front end portion 4233 (particularly the left end edge 4234 of the rear end portion 4232 and the right end edge 4235 of the front end portion 4233) when the second expandable portion 4231 of the second connecting body 423 is deformed to be suitably dispersed. This makes it difficult for the second connecting body 423 to break. Here, in this embodiment, the curvature of each of the rear end portion 4232 and the front end portion 4233 is smaller than that of other portions of the second interconnector 42.

[0067] As described above, in the solar cell module 1, the second interconnector 42 connects the second bus bar electrode 242 and the third bus bar electrode 251, and electricity can be conducted between the second bus bar electrode 242 and the third bus bar electrode 251 through the second interconnector 42.

[0068] The shapes of the first and second expandable portions 4131 and 4231 and the shapes of the first, second, third, and fourth electrodes 411, 412, 421, and 422 when viewed from the top and bottom can be changed as appropriate depending on the cell spacing. The shapes of the first and second expandable portions 4131 and 4231 when viewed from the top and bottom are not limited to a crank-shaped meandering line, and may be, for example, a sinusoidal meandering line or a non-sinusoidal meandering line. The shapes of the first, second, third, and fourth electrodes 411, 412, 421, and 422 when viewed from the top and bottom are not limited to a substantially circular shape, and may be other shapes, such as a substantially rectangular shape.

[0069] 5 is a perspective view showing a part of a solar cell module according to a comparative example. With reference to FIG. 5, the solar cell module 100 according to the comparative example will be described, focusing on the differences from the solar cell module 1 according to the first embodiment.

[0070] 5 shows a first solar cell 2 and a second solar cell 3 connected by an interconnector 4, corresponding to FIG. 2. An enlarged view of a portion of the solar cell 2 and the second solar cell 3 is shown within the two-dot chain line in FIG. 5. As shown in FIG. 5, the solar cell module 100 according to the comparative example has the same configuration as the solar cell module 1 according to the first embodiment, except that it has an interconnector 9 instead of the interconnector 4.

[0071] The interconnector 9 is a wiring material that allows electricity to flow between the first solar cell 2 and the second solar cell 3. The interconnector 9 has a flat plate shape that is horizontal to the first and second solar cells 2, 3. The interconnector 9 is located below the surface electrode 24 and the first semiconductor substrate 21. Furthermore, the interconnector 9 is located below the surface electrode 34 and the second semiconductor substrate 31.

[0072] In this solar cell module 100, ten interconnectors 9 are connected to form an interconnector group 90 extending in the front-to-rear direction. The interconnector group 90 is disposed between the first solar cell 2 and the second solar cell 3. The ten interconnectors 9 included in the interconnector group 90 are integrally formed by stamping a copper plate made of a Cu-Ni-P alloy similar to the interconnector 4.

[0073] The interconnector 9 has a first electrode 91, a second electrode 92, and a connector 93. The first electrode 91 is located on the left end side of the interconnector 9. The first electrode 91 is connected to a first bus bar electrode 241 provided on the first solar cell 2. The second electrode 92 is located on the right end side of the interconnector 9. The second electrode 92 is connected to a third bus bar electrode 251 provided on the second solar cell 3. The connector 93 connects the first electrode 91 and the second electrode 92.

[0074] A first insertion hole 91a penetrating in the vertical direction is formed in the first electrode 91. The first protruding end portion 24b of the first bus bar electrode 241 or the first protruding end portion 24b of the second bus bar electrode 242 is inserted into the first insertion hole 91a from above. The first protruding end portion 24b inserted into the first insertion hole 91a is joined to the first electrode 91 or the second electrode 92 by a joining method such as soldering.

[0075] A second insertion hole 92a penetrating in the vertical direction is formed in the second electrode 92. The second protruding end portion 25b of the third bus bar electrode 251 or the second protruding end portion 25b of the fourth bus bar electrode 252 is inserted into the second insertion hole 92a from below. The second protruding end portion 25b inserted into the second insertion hole 92a is joined to the third electrode 421 or the fourth electrode 422 by a joining method such as soldering.

[0076] The connector 93 has a one-side first detour portion 931, a one-side second detour portion 932, an other-side first detour portion 933, an other-side second detour portion 934, a first connecting portion 935, and a second connecting portion 936. The one-side first detour portion 931 and the other-side first detour portion 933 are located on the left side of the interconnector 9. The one-side second detour portion 932 and the other-side second detour portion 934 are located on the right side of the interconnector 9.

[0077] The one-side first detour portion 931 connects to the first electrode 91 from the rear side. The one-side first detour portion 931 extends linearly toward the rear side of the interconnector 9 so as to move away from the first electrode 91. The one-side first detour portion 931 has a left edge 9311 and a right edge 9312.

[0078] The other-side first detour portion 933 connects to the first electrode 91 from the front side. The other-side first detour portion 933 has a shape symmetrical to the one-side first detour portion 931 in the front-rear direction. As a result, the other-side first detour portion 933 extends linearly toward the front side of the interconnector 9 and away from the first electrode 91. The other-side first detour portion 933 has a left edge 9331 and a right edge 9332.

[0079] Furthermore, the left edges 9311, 9331 of the one-side first detour portion 931 and the other-side first detour portion 933 are curved toward the first solar cell 2 and connected to the first electrode 91. The right edges 9312, 9332 of the one-side first detour portion 931 and the other-side first detour portion 933 are curved toward the second solar cell 3 and connected to the first electrode 91.

[0080] The one-side second detour portion 932 connects to the second electrode 92 from the rear side. The one-side second detour portion 932 has a shape symmetrical in the left-right direction to the one-side first detour portion 931. The one-side second detour portion 932 extends linearly toward the rear side of the interconnector 9 so as to move away from the first electrode 91. The one-side second detour portion 932 has a left edge 9321 and a right edge 9322.

[0081] The other-side second detour portion 934 connects to the first electrode 91 from the front side. The other-side second detour portion 934 has a shape symmetrical to the other-side first detour portion 933 in the front-to-rear direction. As a result, the other-side second detour portion 934 extends linearly toward the front side of the interconnector 9 so as to move away from the first electrode 91. The other-side second detour portion 934 has a left edge 9341 and a right edge 9342.

[0082] Furthermore, the left edges 9321, 9341 of the one-side second detour portion 932 and the other-side second detour portion 934 are curved toward the first solar cell 2 and connect to the first electrode 91. The right edges 9322, 9342 of the one-side second detour portion 932 and the other-side second detour portion 934 are curved toward the second solar cell 3 and connect to the first electrode 91.

[0083] The first connection portion 935 is located at the rear end of the connector 93. The first connection portion 935 extends in the left-right direction while curving in a substantially semicircular shape so as to approach the rear end of the one-side first detour portion 931 and the rear end of the one-side second detour portion 932, respectively. The second connection portion 936 is located at the front end of the connector 93. The second connection portion 936 extends in the left-right direction while curving in a substantially semicircular shape so as to approach the front end of the other-side first detour portion 933 and the front end of the other-side second detour portion 934, respectively. Here, the first and second connection portions have a smaller curvature than other portions of the interconnector 9, and therefore stress is more likely to concentrate thereon than in these other portions.

[0084] The rear end of the one-side first detour portion 931 and the rear end of the one-side second detour portion 932 are connected by a first connecting portion 935. Furthermore, the front end of the other-side first detour portion 933 and the front end of the other-side second detour portion 934 are connected by a second connecting portion 936. In this way, in the interconnector 9, the first electrode 91 and the second electrode 92 are connected by the connecting body 93, and electricity can be conducted between the first electrode 91 and the second electrode 92 via the connecting body 93.

[0085] As described above, in the solar cell module 100, one of the interconnectors 9 adjacent in the front-to-rear direction connects the first bus bar electrode 241 and the third bus bar electrode 251, and the other interconnector 9 connects the second bus bar electrode 242 and the fourth bus bar electrode 252.

[0086] When the cell spacing of the interconnector 9 provided in the solar cell module 100 narrows due to contraction caused by temperature changes during manufacture or use, the first detour portion and the second detour portion of the connector 93 correspondingly deform so as to move closer to each other in the left-right direction. Also, when the cell spacing of the interconnector 9 widens due to expansion caused by temperature changes during manufacture or use, the first detour portion and the second detour portion of the connector 93 correspondingly deform so as to move farther away from each other in the left-right direction.

[0087] Such problems with the solar cell module 100 will be described with reference to Fig. 6. Fig. 6 is a diagram illustrating dimensional changes in the interconnector that occur when the solar cell module according to the comparative example expands due to a temperature change.

[0088] Point A shown in FIG. 6(a) is the connection point between the second electrode 92 and the third bus bar electrode 251 of the interconnector 9 before the solar cell module 100 expands due to a temperature change. Point A' shown in FIG. 6(a) is the connection point between the second electrode 92 and the third bus bar electrode 251 of the interconnector 9 after the solar cell module 100 expands due to a temperature change. Point B shown in FIG. 6(a) is the connection point between the first electrode 91 and the first bus bar electrode 241 of the interconnector 9 before and after the solar cell module 100 expands due to a temperature change. Point C shown in FIG. 6(a) is the connection point between the first electrode 91 and the second bus bar electrode 242 of the interconnector 9 before and after the solar cell module 100 expands due to a temperature change. Point D shown in FIG. 6(a) is the connection point between the second electrode 92 and the fourth bus bar electrode 252 of the interconnector 9 before and after the solar cell module 100 expands due to a temperature change. FIG. 6(b) shows the positional relationship between points A, A', B, and C when interconnector 9 is viewed from above.

[0089] As shown in Figure 6, when the second solar cell 3 is displaced to the right away from the first solar cell 2 relative to the first solar cell 2 due to expansion caused by a temperature change, the connection point between the second electrode 92 and the third bus bar electrode 251 moves from point A to point A', as shown by the white arrow in Figure 6(a). When the connection point between the second electrode 92 and the third bus bar electrode 251 moves in this way, the distance between point A and point B expands to the distance between point A' and point B. In this way, the distance between the first electrode 91 and the second electrode 92 of the interconnector 9 expands in the same direction as the direction in which the second solar cell 3 is displaced, and therefore the interconnector 9 experiences a large dimensional change due to temperature changes.

[0090] In particular, when the front surface member 6 and the back surface member 7 are both made of resin, their thermal expansion coefficients (linear expansion coefficients) are larger than those of the first and second semiconductor substrates 21, 31 made of crystalline silicon or glass, and therefore, when the solar cell module 100 expands or contracts due to temperature changes, the dimensional change of the interconnector 9 becomes significant. Therefore, the inventors conducted an experiment to confirm the change in cell spacing with temperature changes for a solar cell module 100 in which the front surface member 6 and the back surface member 7 are both made of resin containing polycarbonate resin and acrylic resin.

[0091] Fig. 4 is a graph showing changes in the gap between the first solar cell 2 and the second solar cell 3 with respect to temperature changes. The horizontal axis of the graph shown in Fig. 4 represents the ambient temperature (°C). The vertical axis of the graph shown in Fig. 4 represents the cell gap (mm), which is the gap between the first solar cell 2 and the second solar cell 3.

[0092] As can be seen from the graph in Figure 4, when the ambient temperature was lowered from 20°C (room temperature) to -30°C, the cell spacing became narrower by 0.15 mm compared to room temperature. On the other hand, when the ambient temperature was raised from 20°C (room temperature) to 90°C, the cell spacing became wider by 0.45 mm compared to room temperature.

[0093] From the results of this experiment, it was found that subjecting the solar cell module 100 to a temperature change on the high side (20°C to 90°C) results in a greater change in the cell spacing than subjecting it to a temperature change on the low side (20°C to -30°C). When using the solar cell module 1, 100 mounted on a vehicle body, a temperature of around 90°C must be considered as the worst-case condition.

[0094] Therefore, the strength of interconnector 9 when solar cell module 100 is subjected to a temperature change in which the ambient temperature is increased from 20°C to 90°C was evaluated by simulation using an analysis using FEM (Finite Element Method).

[0095] As a result of the FEM analysis, it was confirmed that a tensile stress (688 MPa) exceeding the tensile strength (610 MPa) of the interconnector 9 using KLF170 (registered trademark) can occur in the first and second connection parts 935, 936. As can be seen from this evaluation result, if the first solar cell 2 and the second solar cell 3 are made electrically conductive by the interconnector 9, stress is likely to concentrate in the part of the interconnector 9 with a small curvature when the cell spacing changes. Therefore, with the solar cell module 100, there is a problem in that there is a risk that the first solar cell 2 and the second solar cell 3 will no longer be able to be electrically conductively connected properly if the interconnector 9 breaks.

[0096] In contrast, the solar cell module 1 according to this embodiment has a first solar cell 2, a second solar cell 3 adjacent to the first solar cell 2 at an interval in the left-right direction, which is a first direction, and an interconnector 4 that enables electrical conduction between the first solar cell 2 and the second solar cell. The first solar cell 2 has a first bus bar electrode 241 and a second bus bar electrode 242 adjacent to each other at an interval in the front-rear direction, which is a second direction, and the second solar cell 3 has a third bus bar electrode 251 adjacent to each other at an interval in the front-rear direction, which is the second direction, and aligned in a substantially straight line with the first bus bar electrode 241 along the left-right direction, which is the first direction, and a fourth bus bar electrode 252 aligned in a substantially straight line with the second bus bar electrode 242 along the left-right direction, which is the first direction.

[0097] The interconnector 4 has a first interconnector 41 including a first electrode 411 connected to the first bus bar electrode 241, a second electrode 412 connected to the fourth bus bar electrode 252, and a first connector 413 connecting the first electrode 411 and the second electrode 412. The interconnector 4 also has a second interconnector 42 including a third electrode 421 connected to the second bus bar electrode 242, a fourth electrode 422 connected to the third bus bar electrode 251, and a second connector 423 connecting the third electrode 421 and the fourth electrode 422. Furthermore, the first connector 413 has a first extensible portion 4131 that is extensible in a direction connecting the first electrode 411 and the second electrode 412, and the second connector 423 has a second extensible portion 4231 that is extensible in a direction connecting the third electrode 421 and the second electrode 412.

[0098] FIG. 3 is a diagram illustrating a change in dimension of interconnector 4 that occurs when solar cell module 1 according to the first embodiment expands due to a temperature change.

[0099] Point A shown in FIG. 3(a) is the connection point between the third electrode 421 and the third bus bar electrode 251 of the interconnector 4 before the solar cell module 1 expands due to a temperature change. Point A' shown in FIG. 3(a) is the connection point between the third electrode 421 and the third bus bar electrode 251 of the interconnector 4 after the solar cell module 1 expands due to a temperature change. Point B shown in FIG. 3(a) is the connection point between the first electrode 411 and the first bus bar electrode 241 of the interconnector 4 before and after the solar cell module 1 expands due to a temperature change. Point C shown in FIG. 3(a) is the connection point between the fourth electrode 422 and the second bus bar electrode 242 of the interconnector 4 before and after the solar cell module 1 expands due to a temperature change. Point D shown in FIG. 3(a) is the connection point between the second electrode 412 and the fourth bus bar electrode 252 of the interconnector 4 before and after the solar cell module 1 expands due to a temperature change. FIG. 3(b) shows the positional relationship between points A, A', B, and C when interconnector 4 is viewed from above.

[0100] 3, when the second solar cell 3 is displaced to the right away from the first solar cell 2 relative to the first solar cell 2 due to expansion caused by a temperature change, the connection point between the third electrode 421 and the third bus bar electrode 251 moves from point A to point A', as indicated by the outline arrow in FIG. 3. When the connection point between the third electrode 421 and the third bus bar electrode 251 moves in this way, the distance between point A and point C extends to the distance between point A' and point C. In this way, the distance between the first electrode 411 and the fourth electrode 422 of the interconnector 4 extends in the direction connecting the first electrode 411 and the fourth electrode 422, which intersects with the direction in which the second solar cell 3 is displaced, and therefore the dimensional change that occurs in the interconnector 4 is smaller than the dimensional change that occurs in the interconnector 9.

[0101] As described above, in the solar cell module 1 according to this embodiment, when the cell spacing widens due to expansion of the solar cell module 1 caused by a temperature change, a load acts on the interconnector 4 in both the left and right directions by the first solar cell 2 and the second solar cell 3. When the solar cell module 1 expands due to a temperature change, the load exerted by the first solar cell 2 and the second solar cell 3 on the interconnector 4 causes the first stretchable portion 4131 to stretch in the direction connecting the first electrode 411 and the fourth electrode 422, and the second stretchable portion 4231 to stretch in the direction connecting the second electrode 412 and the third electrode 421. Therefore, dimensional changes in both the left and right directions of the interconnector 4 can be suppressed.

[0102] Furthermore, in the solar cell module 1 according to this embodiment, when the cell spacing narrows due to contraction of the solar cell module 1 caused by a temperature change, a load acts on the interconnector 4 in both the left and right directions by the first solar cell 2 and the second solar cell 3. When the solar cell module 1 contracts due to a temperature change, the interconnector 4 is pressed by the first solar cell 2 and the second solar cell 3, causing the first expandable portion 4131 to contract in the direction connecting the first electrode 411 and the fourth electrode 422, and the second expandable portion 4231 to contract in the direction connecting the second electrode 412 and the third electrode 421. This can suppress inward dimensional changes in the left and right directions of the interconnector 4.

[0103] Furthermore, in the solar cell module 1 according to this embodiment, as described above, when the solar cell module 1 expands or contracts due to a temperature change, the first expanding and contracting portion 4131 expands or contracts in the direction connecting the first electrode 411 and the fourth electrode 422, and the second expanding and contracting portion 4231 expands or contracts in the direction connecting the second electrode 412 and the third electrode 421. This makes it possible to suppress dimensional changes in the front-to-rear direction of the interconnector 4 caused by differences in the linear expansion coefficients of the first and second solar cells 2, 3 and the interconnector 4.

[0104] In the solar cell module 1 described above, it is preferable that the first stretchable portion 4131 and the second stretchable portion 4231 each have a serpentine shape.

[0105] With this configuration, when the cell spacing changes due to contraction of the solar cell module 1 caused by temperature changes, the first and second expansion and contraction portions 4131 and 4231, which have a serpentine shape, elastically deform, thereby reducing the stress generated in the interconnector 4.

[0106] Here, the strength of interconnector 4 when solar cell module 1 is subjected to a temperature change in which the ambient temperature is increased from 20° C. to 90° C. is evaluated based on a simulation by analysis using FEM.

[0107] As a result of the FEM analysis, it was confirmed that the tensile stress (478 MPa) generated at the rear ends 4132, 4232 and front ends 4133, 4233, where stress is more likely to concentrate than at other parts of the interconnector 4, was lower than the tensile strength (610 MPa) of the interconnector 4 using KLF170 (registered trademark). As can be seen from these evaluation results, when the first solar cell 2 and the second solar cell 3 are made electrically conductive by the interconnector 4, it was shown that the interconnector 4 is less likely to break even if stress occurs in parts with a smaller curvature than other parts of the interconnector 4 when the cell spacing changes.

[0108] In the solar cell module 1 described above, the first solar cell 2 has a first semiconductor substrate 21 including a first substrate front surface 22 on which the first bus bar electrode 241 and the second bus bar electrode 242 are formed, and a second substrate back surface 33 on which the third bus bar electrode 251 and the fourth bus bar electrode 252 are formed. The second solar cell 3 has a second semiconductor substrate 31 including a second substrate front surface 32 on which the first bus bar electrode 241 and the second bus bar electrode 242 are formed, and a second substrate back surface 33 on which the third bus bar electrode 251 and the fourth bus bar electrode 252 are formed.

[0109] According to this configuration, by providing double-sided electrode type first and second solar cell cells 2, 3 that are made electrically conductive by the interconnector 4, it is possible to realize a solar cell module 1 that improves power generation efficiency and suppresses a decrease in power generation due to cracking of the first and second solar cell cells 2, 3 or breakage of the interconnector 4.

[0110] In the solar cell module 1 described above, the first bus bar electrode 241 and the second bus bar electrode 242 each have a first protruding end portion 24b protruding from the first semiconductor substrate 21 toward the second solar cell 3, and the third bus bar electrode 251 and the fourth bus bar electrode 252 each have a second protruding end portion 25b protruding from the second semiconductor substrate 31 toward the first solar cell 2. The first connector 413 has a first electrode 411 formed with a first insertion hole 411a into which the first protruding end portion 24b of the first bus bar electrode 241 is inserted from above, and a second electrode 412 formed with a second insertion hole 412a into which the second protruding end portion 25b of the fourth bus bar electrode 252 is inserted from below. This second connector 423 has a third electrode 421 having a third insertion hole 421a formed therein through which the second protruding end 25b of the third busbar electrode 251 is inserted from above, and a fourth electrode 422 having a fourth insertion hole 422a formed therein through which the first protruding end 24b of the second busbar electrode 242 is inserted from below.

[0111] According to this configuration, the first solar cell 2 and the second solar cell 3 can be suitably connected by the interconnector 4 without interference between the first interconnector 41 and the second interconnector 42 .

[0112] Furthermore, the interconnector 4 according to this embodiment allows current to flow between a first solar cell 2 and a second solar cell 3 adjacent to the first solar cell 2 at an interval in the first direction. The first solar cell 2 has a first bus bar electrode 241 and a second bus bar electrode 242 adjacent to each other at an interval in a second direction substantially perpendicular to the first direction. The second solar cell 3 has a third bus bar electrode 251 adjacent to each other at an interval in the second direction and aligned substantially linearly with the first bus bar electrode 241 along the first direction, and a fourth bus bar electrode 252 aligned substantially linearly with the second bus bar electrode 242 along the first direction.

[0113] The interconnector 4 has a first interconnector 41 including a first electrode 411 connected to the first bus bar electrode 241, a second electrode 412 connected to the fourth bus bar electrode 252, and a first connector 413 connecting the first electrode 411 and the second electrode 412. The interconnector 4 also has a second interconnector 42 including a third electrode 421 connected to the second bus bar electrode 242, a fourth electrode 422 connected to the third bus bar electrode 251, and a second connector 423 connecting the third electrode 421 and the fourth electrode 422. Furthermore, the first connector 413 has a first extensible portion 4131 that is extensible in a direction connecting the first electrode 411 and the second electrode 412, and the second connector 423 has a second extensible portion 4231 that is extensible in a direction connecting the third electrode 421 and the second electrode 412.

[0114] In the interconnector 4 according to this embodiment, when the cell spacing widens due to expansion caused by a temperature change, the load exerted by the first solar cell 2 and the second solar cell 3 causes the first stretchable portion 4131 to stretch in the direction connecting the first electrode 411 and the fourth electrode 422, and the second stretchable portion 4231 to stretch in the direction connecting the second electrode 412 and the third electrode 421. Therefore, dimensional changes in both the left and right directions of the interconnector 4 can be suppressed.

[0115] Furthermore, in the interconnector 4 according to this embodiment, when the cell spacing narrows due to contraction caused by temperature changes, the first expandable portion 4131 contracts in the direction connecting the first electrode 411 and the fourth electrode 422, and the second expandable portion 4231 contracts in the direction connecting the second electrode 412 and the third electrode 421, due to the load exerted by the first solar cell 2 and the second solar cell 3. Therefore, dimensional changes inward in the left-right direction of the interconnector 4 can be suppressed.

[0116] Furthermore, as described above, when the interconnector 4 according to this embodiment expands and contracts due to a temperature change, the first expandable portion 4131 expands and contracts in the direction connecting the first electrode 411 and the fourth electrode 422, and the second expandable portion 4231 expands and contracts in the direction connecting the second electrode 412 and the third electrode 421. This makes it possible to suppress dimensional changes in the front-to-rear direction of the interconnector 4 caused by differences in the linear expansion coefficients of the first and second solar cells 2, 3 and the interconnector 4.

[0117] As described above, according to this embodiment, it is possible to provide a solar cell module 1 and an interconnector 4 that suppress poor electrical conductivity between the first solar cell 2 and the second solar cell 3 and have improved durability when the distance between adjacent first solar cell 2 and second solar cell 3 changes.

[0118] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0119] 1 Solar cell module 2 First solar cell 3 Second solar cell 4, 9 Interconnector 5 Sealing material 6 Surface material 7 Back surface material 21 First semiconductor substrate 22 First substrate front surface 23 First substrate back surface 24, 34 Surface electrode 24a First base 24b First protruding end 25, 35 Back electrode 25a Second base 25b Second protruding end 31 second semiconductor substrate 32 second substrate front surface 33 second substrate back surface 40 Interconnector Group 41 First interconnector 42 Second interconnector 61 Entrance plane 62 Output plane 71 Front 72 Back 90 Interconnector Group 91 First electrode 91a First insertion hole 92 Second electrode 92a Second insertion hole 93 Connectors 241, 341 First bus bar electrode 242, 342 Second bus bar electrode 251, 351 Third bus bar electrode 252, 352 Fourth bus bar electrode 411 First electrode 411a First insertion hole 412 Second electrode 412a Second insertion hole 413 First Connector 421 Third electrode 421a Third insertion hole 422 Fourth electrode 422a Fourth insertion hole 423 Second Connector 931 First detour section on one side 932 Second detour section on one side 933: First detour section on the other side 934: Second detour section on the other side 935 First connection part 936 Second connection part 4111 Right edge 4121 Left edge 4131 1st telescoping section 4231 2nd telescoping section 4132, 4232 Rear end 4133, 4233 Front end 4134, 4211, 4234, 9311, 9321, 9331, 9341 Left edge 4135, 4221, 4235, 9312, 9322, 9332, 9342 Right edge

Claims

1. a first solar cell; a second solar cell adjacent to the first solar cell at an interval in a first direction; an interconnector that allows electrical conduction between the first solar cell and the second solar cell, The first solar cell is a first bus bar electrode and a second bus bar electrode adjacent to each other and spaced apart in a second direction substantially perpendicular to the first direction; The second solar cell is a third bus bar electrode that is adjacent to the first bus bar electrode at an interval in the second direction and aligned substantially linearly with the first bus bar electrode along the first direction; and a fourth bus bar electrode that is aligned substantially linearly with the second bus bar electrode along the first direction, The interconnector is a first interconnector including: a first electrode connected to the first bus bar electrode; a second electrode connected to the fourth bus bar electrode; and a first connector connecting the first electrode and the second electrode; a second interconnector including a third electrode connected to the second bus bar electrode, a fourth electrode connected to the third bus bar electrode, and a second connector connecting the third electrode and the fourth electrode, The first connector is a first stretchable portion that is stretchable in a direction connecting the first electrode and the second electrode; The second connector is The solar cell module has a second expansion and contraction section that is expandable in a direction connecting the third electrode and the second electrode.

2. The first stretchable portion and the second stretchable portion are The solar cell module of claim 1 , each having a serpentine shape.

3. The first solar cell is a first semiconductor substrate including a first substrate surface on which the first bus bar electrode and the second bus bar electrode are formed and a second substrate back surface on which the third bus bar electrode and the fourth bus bar electrode are formed, The second solar cell is 2. The solar cell module according to claim 1, further comprising a second semiconductor substrate including a second substrate front surface on which the first bus bar electrode and the second bus bar electrode are formed and a second substrate rear surface on which the third bus bar electrode and the fourth bus bar electrode are formed.

4. The first bus bar electrode and the second bus bar electrode are each having a first protruding end portion protruding from the first semiconductor substrate toward the second solar cell; The third bus bar electrode and the fourth bus bar electrode are each having a second protruding end portion protruding from the second semiconductor substrate toward the first solar cell; The first connector is the first electrode is formed with a first insertion hole into which the first protruding end portion of the first bus bar electrode is inserted from above, and the second electrode is formed with a second insertion hole into which the second protruding end portion of the fourth bus bar electrode is inserted from below, The second connector is 4. The solar cell module according to claim 3, further comprising: the third electrode having a third insertion hole formed therein, into which the second protruding end of the third bus bar electrode is inserted from above; and the fourth electrode having a fourth insertion hole formed therein, into which the first protruding end of the second bus bar electrode is inserted from below.

5. An interconnector that allows current to flow between a first solar cell and a second solar cell that is adjacent to the first solar cell and spaced apart in a first direction, The first solar cell is a first bus bar electrode and a second bus bar electrode adjacent to each other and spaced apart in a second direction substantially perpendicular to the first direction; The second solar cell is a third bus bar electrode that is adjacent to the first bus bar electrode at an interval in the second direction and aligned substantially linearly with the first bus bar electrode along the first direction; and a fourth bus bar electrode that is aligned substantially linearly with the second bus bar electrode along the first direction, The interconnector is a first interconnector including: a first electrode connected to the first bus bar electrode; a second electrode connected to the fourth bus bar electrode; and a first connector connecting the first electrode and the second electrode; a second interconnector including a third electrode connected to the second bus bar electrode, a fourth electrode connected to the third bus bar electrode, and a second connector connecting the third electrode and the fourth electrode, The first connector is a first stretchable portion that is stretchable in a direction connecting the first electrode and the second electrode; The second connector is An interconnector having a second stretchable portion that is stretchable in a direction connecting the third electrode and the second electrode.

Images