Solar cell module and manufacturing method for the same

Abstract

To suppress the occurrence of defects in wiring connecting solar power generation cells and electric terminals.SOLUTION: A solar cell module includes a transparent plate member, a plurality of solar power generation cells 21 arranged on the transparent plate member, and a terminal box 30 that includes a plurality of electrode terminals 31_1, 31_2 that are electrically connected to the plurality of solar power generation cells 21. The plurality of solar power generation cells 21 is connected to the plurality of electrode terminals 31_1, 31_2 via a plurality of electrical wires. The plurality of electrical wires has lead-containing solder on the solar power generation cells 21 side, and partially includes a wire having lead-free solder on the terminal electrodes 31_1, 31_2 side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a solar cell module and a method for manufacturing a solar cell module. [Background technology]

[0002] In recent years, the use of solar cell modules equipped with multiple solar cells has been promoted in order to utilize natural energy. In a solar cell module equipped with multiple solar cells, wiring connected to the solar cells is taken out from inside the solar cell module to the outside in order to take out the power generated by the solar cells. The wiring thus taken out is then connected to an electrode terminal provided in a terminal box.

[0003] Patent Document 1 discloses a technique relating to a connection structure that electrically connects an electrode wire from a solar cell module to a terminal plate of a terminal box of the solar cell module. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-154498 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a solar cell module, multiple photovoltaic cells are connected to each other using tab wiring. The tab wiring is connected to the photovoltaic cells using solder. In this case, if lead-free solder is used to connect the tab wiring to the photovoltaic cells, the lead-free solder is hard and there is a risk of the photovoltaic cells cracking at the points where the tab wiring is connected. For this reason, leaded solder, which is softer than lead-free solder, is used when connecting the tab wiring to the photovoltaic cells.

[0006] Therefore, wiring plated with leaded solder is also used for the bus bar wiring to which the tab wiring is connected. However, leaded solder may crack in the lead in the solder after long-term use. This may cause problems in the wiring connecting the photovoltaic power generation cells and the electrode terminals.

[0007] In view of the above problems, an object of the present invention is to provide a solar cell module capable of suppressing the occurrence of defects in wiring connecting photovoltaic power generation cells and electrode terminals, and a method for manufacturing the solar cell module. [Means for solving the problem]

[0008] A solar cell module and a method for manufacturing the solar cell module according to one aspect of the present invention are as follows.

[0009] [1] A transparent plate-like member; A plurality of photovoltaic cells arranged on the transparent plate-shaped member; a terminal box including electrode terminals electrically connected to the plurality of photovoltaic cells, the plurality of photovoltaic cells are connected to the electrode terminals via a plurality of wirings, The plurality of wirings include wirings having lead-containing solder on the photovoltaic power generation cell side and having lead-free solder on the electrode terminal side. Solar cell module.

[0010] [2] The plurality of wirings include A first wiring electrically connected to the plurality of photovoltaic cells; a second wiring connected to the first wiring and the electrode terminal; lead-containing solder is provided on one side of the second wiring in the longitudinal direction, and lead-free solder is provided on the other side of the second wiring in the longitudinal direction; the one side of the second wiring is soldered to the first wiring using the lead-containing solder; The other side of the second wiring is soldered to the electrode terminal using the lead-free solder. [1] The solar cell module according to claim 1.

[0011] [3] The plurality of wirings include a tab wiring that connects the plurality of photovoltaic cells to each other; A first wiring connected to the tab wiring; a second wiring connected to the first wiring and the electrode terminal; lead-containing solder is provided on one side of the first wiring in the longitudinal direction, and lead-free solder is provided on the other side of the first wiring in the longitudinal direction; the one side of the first wiring is soldered to the tab wiring using the leaded solder, The other side of the first wiring is soldered to the second wiring using the lead-free solder. [1] The solar cell module according to claim 1.

[0012] [4] The plurality of wirings include a tab wiring that connects the plurality of photovoltaic cells to each other; A first wiring connected to the tab wiring; a second wiring connected to the first wiring and the electrode terminal; The tab wiring connected to the first wiring among the tab wirings has lead solder provided on one side in a longitudinal direction and lead-free solder provided on the other side in the longitudinal direction, The one side of the tab wiring connected to the first wiring is soldered to the solar power generation cell using the lead-containing solder, and the other side is soldered to the first wiring using the lead-free solder. [1] The solar cell module according to claim 1.

[0013] [5] The solar cell module according to any one of [1] to [4], wherein the lead-free solder contains tin and silver, and the tin content is 90 mass % or more.

[0014] [6] The solar cell module according to any one of [1] to [4], wherein the melting point of the lead-free solder is higher than the melting point of the leaded solder.

[0015] [7] the transparent plate-like member is a laminated glass including a first glass plate, a second glass plate, and an intermediate adhesive layer disposed between the first glass plate and the second glass plate; the plurality of photovoltaic cells are disposed within the intermediate adhesive layer; The solar cell module according to any one of [1] to [4].

[0016] [8] the second wiring is a ribbon-shaped wiring having a predetermined width, the lead-containing solder is plated on both sides of the second wiring on the one side of the second wiring, the lead-free solder is plated on both sides of the second wiring at the other side of the second wiring; [2] The solar cell module according to claim 1.

[0017] [9] the second wiring is a ribbon-shaped wiring having a predetermined width, lead-containing solder is provided on one surface of the second wiring, and lead-free solder is provided on the other surface of the second wiring; a region where no lead-free solder is formed on the other surface of the second wiring is formed on the one side of the second wiring, a region where no lead-containing solder is formed on the one surface of the second wiring is formed on the other side of the second wiring; [2] The solar cell module according to claim 1.

[0018]

[10] The first wiring is a ribbon-shaped wiring having a predetermined width, the lead-containing solder is plated on both sides of the first wiring on the one side of the first wiring, the lead-free solder is plated on both sides of the first wiring at the other side of the first wiring; [3] The solar cell module according to [3].

[0019]

[11] The first wiring is a ribbon-shaped wiring having a predetermined width, lead-containing solder is provided on one surface of the first wiring, and lead-free solder is provided on the other surface of the first wiring; a region where no lead-free solder is formed on the other surface of the first wiring is formed on the one side of the first wiring, a region where no lead-containing solder is formed on the one surface of the first wiring is formed on the other side of the first wiring; [3] The solar cell module according to [3].

[0020]

[12] the first wiring includes a first bus bar wiring on a positive side and a first bus bar wiring on a negative side, the second wiring includes a positive second bus bar wiring and a negative second bus bar wiring, The electrode terminal includes a positive electrode terminal and a negative electrode terminal, The plurality of photovoltaic cells are connected in series to each other using tab wiring, a positive side of the tab wiring that connects the plurality of photovoltaic power generation cells in series is connected to a first bus bar wiring on the positive side, a negative side of the tab wiring that connects the plurality of photovoltaic power generation cells in series is connected to a first bus bar wiring on the negative side, the first positive bus bar wiring is connected to the positive electrode terminal via the second positive bus bar wiring, the negative-side first bus bar wiring is connected to the negative-side electrode terminal via the negative-side second bus bar wiring, The solar cell module according to any one of [2] to [4].

[0021]

[13] Arranging a plurality of photovoltaic cells on a transparent plate-shaped member; a step of disposing a terminal box on the plate-like member; and electrically connecting electrode terminals of the terminal box to the plurality of photovoltaic cells, the plurality of photovoltaic cells are connected to the electrode terminals via a plurality of wirings; The plurality of wirings include wirings having lead-containing solder on the photovoltaic power generation cell side and having lead-free solder on the electrode terminal side. A method for manufacturing a solar cell module. Effect of the Invention

[0022] The present invention can provide a solar cell module capable of suppressing defects in wiring connecting a photovoltaic power generation cell and an electrode terminal, and a method for manufacturing the solar cell module. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a front view showing a solar cell module according to a first embodiment. [Diagram 2] 1 is a cross-sectional view showing a solar cell module according to a first embodiment. [Diagram 3] 1 is an enlarged front view showing a solar cell module according to a first embodiment. [Figure 4] 2 is a cross-sectional view showing the vicinity of a hole in the solar cell module according to the first embodiment. [Diagram 5] FIG. 2 is a front view of a terminal box included in the solar cell module according to the first embodiment. [Figure 6] 4 is a cross-sectional view showing a state in which bus bar wiring is connected to an electrode terminal. FIG. [Figure 7] FIG. 2 is a cross-sectional view showing a configuration example of bus bar wiring. [Figure 8] FIG. 11 is a cross-sectional view showing another configuration example of the bus bar wiring. [Figure 9] FIG. 11 is a front view showing a solar cell module according to a second embodiment. [Figure 10] FIG. 11 is a cross-sectional view showing wiring provided in a solar cell module according to a second embodiment. [Figure 11] FIG. 11 is a front view showing a solar cell module according to a third embodiment. [Figure 12] FIG. 11 is a cross-sectional view showing wiring provided in a solar cell module according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] <Outline of the invention> A solar cell module according to one aspect of the present invention includes a transparent plate-shaped member, a plurality of photovoltaic cells arranged on the transparent plate-shaped member, and a terminal box including electrode terminals electrically connected to the plurality of photovoltaic cells. The plurality of photovoltaic cells are connected to the electrode terminals via a plurality of wirings. The plurality of wirings includes, in part, wirings having lead-containing solder on the photovoltaic cell side and lead-free solder on the electrode terminal side.

[0025] In the present invention, some of the wiring connecting the photovoltaic cells and the electrode terminals has lead solder on the photovoltaic cell side and lead-free solder on the electrode terminal side. Therefore, lead solder can be used for connection to the photovoltaic cells while lead-free solder can be used for connection to the multiple wirings and electrode terminals, so that the occurrence of problems in the wiring connecting the photovoltaic cells and the electrode terminals can be suppressed.

[0026] Three embodiments of the present invention will be described below. (1) In the first embodiment, a configuration example will be described in which the bus bar wiring 25 (see FIG. 1) is wiring having lead-containing solder on the photovoltaic power generation cell side and lead-free solder on the electrode terminal side. (2) In the second embodiment, a configuration example will be described in which the bus bar wiring 24 (see FIG. 9) is wiring having lead-containing solder on the photovoltaic power generation cell side and lead-free solder on the electrode terminal side. (3) In the third embodiment, a configuration example will be described in which the tab wiring 71 (see FIG. 11) is wiring having lead-containing solder on the photovoltaic power generation cell side and lead-free solder on the electrode terminal side.

[0027] <Embodiment 1> Fig. 1 is a front view showing a solar cell module according to embodiment 1. Fig. 2 is a cross-sectional view showing the solar cell module according to embodiment 1.

[0028] As shown in Fig. 1, the solar cell module 1 according to this embodiment includes a plurality of solar cells 21, tab wiring 22, bus bar wiring 23_1 to 23_3, 24_1 to 24_2, 25_1 to 25_2, and a terminal box 30. The plurality of solar cells 21 are arranged on a transparent plate-like member 10 so as to be aligned in the x-axis direction and the y-axis direction. The transparent plate-like member 10 is typically laminated glass. Hereinafter, in this embodiment, a case where laminated glass 10 is used as the transparent plate-like member will be described. The solar cell module 1 (laminated glass) according to this embodiment can be suitably used as a building material such as window glass for buildings.

[0029] As shown in Fig. 2, the laminated glass 10 includes a first glass plate 11, a second glass plate 12, and an intermediate adhesive layer 13 disposed between the first glass plate 11 and the second glass plate 12. A plurality of photovoltaic cells 21_1, 21_2 are disposed inside the intermediate adhesive layer 13. Note that in this specification, the photovoltaic cells 21_1, 21_2 are also collectively referred to as photovoltaic cells 21. The same applies to the other components.

[0030] The laminated glass 10 is configured by stacking a first glass plate 11, an intermediate adhesive layer 13, and a second glass plate 12 in the z-axis direction, and the first glass plate 11 and the second glass plate 12 are bonded to each other using the intermediate adhesive layer 13. A plurality of photovoltaic cells 21_1, 21_2 are enclosed between the first glass plate 11 and the second glass plate 12, i.e., inside the intermediate adhesive layer 13.

[0031] The thickness of the first glass plate 11 and the second glass plate 12 is preferably 4 mm or more and 12 mm or less. For example, chemically strengthened glass may be used as the first glass plate 11 and the second glass plate 12. When chemically strengthened glass is used, the first glass plate 11 and the second glass plate 12 can be made lighter while maintaining the strength of the first glass plate 11 and the second glass plate 12. In the present embodiment, air-cooled strengthened glass may be used as the first glass plate 11 and the second glass plate 12.

[0032] The intermediate adhesive layer 13 is disposed so as to be sandwiched between the first glass plate 11 and the second glass plate 12. In other words, the first glass plate 11 and the second glass plate 12 are bonded using the intermediate adhesive layer 13. For example, when forming the solar cell module 1, the first glass plate 11, the intermediate adhesive layer 13, the solar cell 21, the intermediate adhesive layer 13, and the second glass plate 12 are laminated in this order, and the laminate is heated and pressurized to bond them together, thereby forming the solar cell module 1. At this time, the intermediate adhesive layer 13 disposed below the solar cell 21 and the intermediate adhesive layer 13 disposed above the solar cell 21 are heated and melted, so that the solar cell module 1 after completion becomes a single layer of intermediate adhesive layer 13.

[0033] The thickness of the intermediate adhesive layer 13 is preferably 0.38 mm or more and 2.28 mm or less. The intermediate adhesive layer 13 may be made of EVA (ethylene-vinyl acetate copolymer) resin, PVB (polyvinyl butyral) resin, ionomer resin, COP (cycloolefin polymer), polyurethane, PVC (polyvinyl chloride), POE (polyolefin elastomer), TPO (olefin-based thermoplastic elastomer), etc. The intermediate adhesive layer 13 may also be made of a combination of these materials.

[0034] The photovoltaic cells 21 can be configured using photovoltaic cells of silicon-based single crystal type, silicon-based polycrystalline type, amorphous silicon type, thin film silicon type, CIGS type, organic thin film type, dye-sensitized type, perovskite type, or the like. In the configuration example shown in FIG. 1, each photovoltaic cell 21 has a rectangular shape. For example, each photovoltaic cell 21 may have a square, rectangular, or circular shape. Also, for example, a single-sided light-receiving type photovoltaic cell may be used as the photovoltaic cell 21. In this case, the light-receiving surface of the photovoltaic cell 21 is arranged so as to face outward (the negative side in the z-axis direction). Also, a double-sided light-receiving type photovoltaic cell may be used as the photovoltaic cell 21.

[0035] As shown in Fig. 1, the multiple photovoltaic cells 21 are electrically connected to each other using tab wiring 22. Specifically, the photovoltaic cells 21 have a semiconductor substrate on which a pn junction is formed. For example, the photovoltaic cells 21 have an n-type semiconductor disposed on a light-receiving surface and a p-type semiconductor disposed on a surface (back surface) opposite to the light-receiving surface. In this embodiment, the multiple photovoltaic cells 21 disposed in the y-axis direction are configured to be connected to each other in series using the tab wiring 22.

[0036] That is, as shown in FIG. 2, a tab wiring 22_1 is connected to the light receiving surface (surface on the negative side in the z-axis direction) of the photovoltaic cell 21_1, and a tab wiring 22_2 is connected to the back surface (surface on the positive side in the z-axis direction) of the photovoltaic cell 21_1. Further, a tab wiring 22_2 is connected to the light receiving surface (surface on the negative side in the z-axis direction) of the photovoltaic cell 21_2 adjacent to the photovoltaic cell 21_1, and a tab wiring 22_3 is connected to the back surface (surface on the positive side in the z-axis direction) of the photovoltaic cell 21_2. By configuring in this manner, the multiple photovoltaic cells 21 arranged in the y-axis direction can be connected in series with each other using the tab wiring 22. In the configuration example shown in FIG. 1, four photovoltaic cell groups 20_1 to 20_4 are formed in which the multiple photovoltaic cells 21 arranged in the y-axis direction are connected by the tab wiring 22. Copper or aluminum can be used as the material of the tab wiring 22.

[0037] The four photovoltaic cell groups 20_1 to 20_4 are connected in series with each other using busbar wirings 23_1 to 23_3. Specifically, the photovoltaic cell group 20_1 and the photovoltaic cell group 20_2 are connected with each other on the positive side in the y-axis direction using the busbar wiring 23_1. The photovoltaic cell group 20_2 and the photovoltaic cell group 20_3 are connected with each other on the negative side in the y-axis direction using the busbar wiring 23_2. The photovoltaic cell group 20_3 and the photovoltaic cell group 20_4 are connected with each other on the positive side in the y-axis direction using the busbar wiring 23_3. The negative side in the y-axis direction of the photovoltaic cell group 20_1 is connected with the busbar wiring 24_1, and the negative side in the y-axis direction of the photovoltaic cell group 20_4 is connected with the busbar wiring 24_2. For example, the busbar wiring 24_1 is a negative side busbar wiring (first wiring), and the busbar wiring 24_2 is a positive side busbar wiring (first wiring).

[0038] Furthermore, the end of the busbar wiring 24_1 on the positive side in the x-axis direction is connected to the end of the busbar wiring 25_1 on the positive side in the y-axis direction by using leaded solder 28_1. Similarly, the end of the busbar wiring 24_2 on the negative side in the x-axis direction is connected to the end of the busbar wiring 25_2 on the positive side in the y-axis direction by using leaded solder 28_2. The end of the busbar wiring 25_1 on the negative side in the y-axis direction and the end of the busbar wiring 25_2 on the negative side in the y-axis direction are connected to electrode terminals 31_1 and 31_2 (see FIG. 5 ) provided in the terminal box 30. For example, the busbar wiring 25_1 is a negative side busbar wiring (second wiring), and the busbar wiring 25_2 is a positive side busbar wiring (second wiring). The electrode terminal 31_1 is a negative side electrode terminal, and the electrode terminal 31_2 is a positive side electrode terminal. The busbar wirings 23, 24, and 25 can be made of copper or aluminum. With this configuration, the power generated by the multiple photovoltaic power generation cells 21 can be extracted.

[0039] 1 shows a configuration example in which the multiple photovoltaic cells 21 are connected to each other using three tab wirings 22, but the number of tab wirings 22 connecting the multiple photovoltaic cells 21 to each other may be other than three. Also, while Fig. 1 shows a configuration example in which all the photovoltaic cells 21 are connected in series, in this embodiment, some of the photovoltaic cells 21 may be connected in parallel.

[0040] FIG. 3 is an enlarged front view showing the solar cell module according to the first embodiment. FIG. 4 is a cross-sectional view showing the vicinity of the hole of the solar cell module according to the first embodiment. In this embodiment, holes 26_1 and 26_2 are provided in the second glass sheet 12, and the bus bar wirings 25_1 and 25_2 are taken out from the inside of the laminated glass 10 to the outside through the holes 26_1 and 26_2. In addition, as shown in FIG. 3 and FIG. 4, sealing materials 27_1 and 27_2 that seal between the holes 26_1 and 26_2 and the intermediate adhesive layer 13 are provided between the first glass sheet 11 and the second glass sheet 12 around the holes 26_1 and 26_2. As shown in FIG. 4, the bus bar wiring 25 is sandwiched between the sealing material 27 arranged on the first glass sheet 11 side and the sealing material 27 arranged on the second glass sheet 12 side at the hole 26, and is taken out to the outside of the laminated glass 10 through the sealing material 27 and the hole 26. With this configuration, the gap between the hole 26 and the intermediate adhesive layer 13 can be appropriately sealed.

[0041] Fig. 5 is a front view of a terminal box included in the solar cell module according to the first embodiment. Fig. 6 is a cross-sectional view showing a state in which bus bar wiring is connected to the electrode terminals. Note that Fig. 5 shows a state in which the lid is removed in order to show the inside of the terminal box. As shown in Fig. 5, the terminal box 30 includes electrode terminals 31_1, 31_2, a terminal block 33, output cables 34_1, 34_2, and a bypass diode 35. The terminal box 30 is attached to the outer main surface of the second glass plate 12.

[0042] As shown in Fig. 5 and Fig. 6, the electrode terminals 31_1, 31_2 are fixed to a terminal block 33. The bus bar wirings 25_1, 25_2 taken out through the holes 26_1, 26_2 are connected to the electrode terminals 31_1, 31_2 using lead-free solders 32_1, 32_2, respectively. As shown in Fig. 5, the electrode terminals 31_1, 31_2 are electrically connected to output cables 34_1, 34_2, respectively. Thus, the power generated by the solar cell module 1 is output to the outside using the output cables 34_1, 34_2.

[0043] In addition, a bypass diode 35 is provided between the electrode terminal 31_1 and the electrode terminal 31_2. This allows the current to pass through the bypass diode 35 without passing through the photovoltaic power generation cell 21 when the photovoltaic power generation cell 21 fails. In other words, when the output cables 34_1, 34_2 are connected to other solar cell modules, if the photovoltaic power generation cell 21 included in the solar cell module 1 fails, the current stops flowing through the solar cell module 1, and the other solar cell modules are also affected. On the other hand, when the bypass diode 35 is provided, if the photovoltaic power generation cell 21 fails, the current flows through the bypass diode 35 without passing through the photovoltaic power generation cell 21, so that the effect on the other solar cell modules can be prevented.

[0044] In this embodiment, it is preferable to arrange the terminal box 30 so as to overlap the holes 26_1 and 26_2 when the second glass plate 12 is viewed in plan as shown in Fig. 5. By arranging it in this manner, the holes 26_1 and 26_2 can be made invisible from the outside. Therefore, the design of the solar cell module 1 can be improved.

[0045] In this embodiment, one side of the busbar wiring (second wiring) 25_1 is soldered to the busbar wiring (first wiring) 24_1 using lead-containing solder 28_1 (see FIG. 1), and the other side of the busbar wiring 25_1 is soldered to the electrode terminal 31_1 using lead-free solder 32_1 (see FIG. 5 and FIG. 6). Similarly, one side of the busbar wiring (second wiring) 25_2 is soldered to the busbar wiring (first wiring) 24_2 using lead-containing solder 28_2 (see FIG. 1), and the other side of the busbar wiring 25_2 is soldered to the electrode terminal 31_2 using lead-free solder 32_2 (see FIG. 5 and FIG. 6). Thus, the invention according to this embodiment can suppress the occurrence of defects in the connection between the electrode terminals 31_1, 31_2 and the busbar wirings 25_1, 25_2.

[0046] That is, as described in the Background Art, in a solar cell module, a plurality of photovoltaic power generation cells are connected to each other using tab wiring. The tab wiring is connected to the photovoltaic power generation cells using solder. In this case, if the tab wiring is connected to the photovoltaic power generation cells using lead-free solder, there is a risk that the portion of the photovoltaic power generation cell to which the tab wiring is connected may crack because the lead-free solder is hard. For this reason, when connecting the tab wiring to the photovoltaic power generation cells, leaded solder, which is softer than lead-free solder, has been used.

[0047] Therefore, wiring plated with leaded solder was also used for the bus bar wiring to which the tab wiring is connected. In other words, since the tab wiring and the bus bar wiring to which the tab wiring is connected are used in large quantities, it is necessary to improve productivity, and wiring plated with leaded solder is manufactured by roll-to-roll and this plated wiring is cut and used. For this reason, the electrode terminals and bus bar wiring provided in the terminal box are connected using leaded solder. However, if leaded solder is used for a long period of time, there is a risk that cracks will occur in the lead in the solder. For this reason, there are cases where problems occur in the connection between the electrode terminals and the bus bar wiring.

[0048] In contrast, in the present embodiment, lead-containing solder is used to connect the photovoltaic power generation cell 21 and the tab wiring 22, while lead-free solders 32_1, 32_2 are used to connect the bus bar wirings (second wirings) 25_1, 25_2 and the electrode terminals 31_1, 31_2. This makes it possible to suppress the occurrence of defects in the connections between the bus bar wirings 25_1, 25_2 and the electrode terminals 31_1, 31_2.

[0049] FIG. 7 is a cross-sectional view showing a configuration example of a busbar wiring. For example, as shown in FIG. 7, the busbar wiring 25 is provided with leaded solder 41 on one side 51 in the longitudinal direction of the busbar wiring 25 and with lead-free solder on the other side 52 in the longitudinal direction of the busbar wiring 25. For example, the busbar wiring 25 may be a ribbon-shaped wiring having a predetermined width. In this case, the busbar wiring 25 may be provided with leaded solder 41 plated on both sides of the busbar wiring 25 on one side 51 of the busbar wiring 25, or with lead-free solder 42 plated on both sides of the busbar wiring 25 on the other side 52 of the busbar wiring 25. Note that FIG. 7 shows a configuration example in which the leaded solder 41 and the lead-free solder 42 are plated on both sides of the busbar wiring 25. However, in this embodiment, the leaded solder 41 and the lead-free solder 42 may be plated on one side of the busbar wiring 25.

[0050] For example, the lead-free solder 42 is not particularly limited, but is preferably a lead-free solder containing Sn (tin) and Ag (silver), such as Sn-Ag solder, Sn-Ag-In solder, Sn-Ag-Al-Zn solder, Sn-Al-In-Ag-Cu-Zn solder, or Sn-Ag-Cu solder. In this case, the content of Sn (tin) is preferably 90 mass% or more, more preferably 95 mass% or more. As the leaded solder 41, for example, a eutectic solder containing Sn (tin) and Pb (lead) can be used. As an example, a eutectic solder containing Sn (tin) of 55 to 65 mass% and Pb (lead) of 35 to 45 mass% can be used. The melting point of the lead-free solder 42 may be higher than the melting point of the leaded solder 41.

[0051] In this embodiment, one side 51 of the busbar wiring 25 plated with the leaded solder 41 and the lead-free solder 42, i.e., the side plated with the leaded solder 41, is brought into contact with the busbar wiring 24. Then, by melting the leaded solder 41, it is possible to connect one side 51 of the busbar wiring 25 to the busbar wiring 24. Also, the other side 52 of the busbar wiring 25 plated with the leaded solder 41 and the lead-free solder 42, i.e., the side plated with the lead-free solder 42, is brought into contact with the electrode terminal 31. Then, by melting the lead-free solder 42, it is possible to connect the other side 52 of the busbar wiring 25 to the electrode terminal 31.

[0052] FIG. 8 is a cross-sectional view showing another example of the configuration of the busbar wiring. For example, as shown in FIG. 8, the busbar wiring 25 is a ribbon-shaped wiring having a predetermined width. A lead-containing solder 41 is provided on one surface of the busbar wiring 25, and a lead-free solder 42 is provided on the other surface of the busbar wiring 25. On one side 51 of the busbar wiring 25, a region 46 is formed on the other surface of the busbar wiring 25 where the lead-free solder 42 is not formed. Also, on the other side 52 of the busbar wiring 25, a region 45 is formed on one surface of the busbar wiring 25 where the lead-containing solder 41 is not formed. For example, in a state where a solder resist or a masking tape is provided on the regions 45 and 46 of the busbar wiring 25, the region 45 where the lead-containing solder 41 is not formed and the region 46 where the lead-free solder 42 is not formed can be formed by plating the lead-containing solder 41 and the lead-free solder 42.

[0053] Also in the bus bar wiring 25 shown in FIG. 8, one side 51 of the bus bar wiring 25, that is, the side on which the leaded solder 41 is plated, is brought into contact with the bus bar wiring 24. Then, by melting the leaded solder 41, one side 51 of the bus bar wiring 25 can be connected to the bus bar wiring 24. Further, the other side 52 of the bus bar wiring 25, that is, the side on which the lead-free solder 42 is plated, is brought into contact with the electrode terminal 31. Then, by melting the lead-free solder 42, the other side 52 of the bus bar wiring 25 can be connected to the electrode terminal 31. In the bus bar wiring 25 shown in FIG. 8, since the regions 45 where the leaded solder 41 is not formed and the regions 46 where the lead-free solder 42 is not formed are formed, mixing of the leaded solder 41 and the lead-free solder 42 can be suppressed on one side 51 and the other side 52 of the bus bar wiring 25.

[0054] Next, a method for manufacturing a solar cell module according to the present embodiment will be described. When forming the solar cell module 1 according to the present embodiment, first, the first glass plate 11, the intermediate adhesive layer 13, the solar power generation cell 21, the intermediate adhesive layer 13, and the second glass plate 12 are laminated in this order. At this time, as shown in FIG. 1, each solar power generation cell 21 is connected in series using the tab wiring 22 and the bus bar wirings 23_1 to 23_3. Further, the minus side in the y-axis direction of the solar power generation cell group 20_1 and the bus bar wiring 24_1 are connected. Similarly, the minus side in the y-axis direction of the solar power generation cell group 20_4 and the bus bar wiring 24_2 are connected. Leaded solder is used for the connection between the solar power generation cell 21 and the tab wiring 22, and the connection between the tab wiring 22 and the bus bar wirings 23_1 to 23_3 and 24_1 to 24_2.

[0055] Furthermore, the end portion on the plus side in the x-axis direction of the bus bar wiring 24_1 and the end portion on the plus side in the y-axis direction of the bus bar wiring 25_1 are soldered using the leaded solder 28_1. Similarly, the end portion on the minus side in the x-axis direction of the bus bar wiring 24_2 and the end portion on the plus side in the y-axis direction of the bus bar wiring 25_2 are soldered using the leaded solder 28_2.

[0056] Then, in a state where the ends of the busbar wirings 25_1 and 25_2 on the negative side in the y-axis direction are exposed from the holes 26_1 and 26_2 provided in the second glass plate 12, respectively, the laminate is heated and pressurized to be bonded. At this time, the intermediate adhesive layer 13 arranged on the lower side of the photovoltaic power generation cell 21 and the intermediate adhesive layer 13 arranged on the upper side are heated and melted, so that the completed solar cell module 1 becomes one intermediate adhesive layer 13 (see FIG. 2). In addition, seal materials 27_1 and 27_2 are provided between the first glass plate 11 and the second glass plate 12 around the holes 26_1 and 26_2 to seal between the holes 26_1 and 26_2 and the intermediate adhesive layer 13. The busbar wirings 25_1 and 25_2 are sandwiched between the seal material 27 arranged on the first glass plate 11 side and the seal material 27 arranged on the second glass plate 12 side at the holes 26_1 and 26_2.

[0057] Thereafter, the terminal box 30 is attached to the outer main surface of the second glass plate 12 (see Figs. 1 and 5). Then, the electrode terminal 31_1 of the terminal box 30 is soldered to the end of the busbar wiring 25_1 on the negative side in the y-axis direction by using lead-free solder 32_1. Similarly, the electrode terminal 31_2 of the terminal box 30 is soldered to the end of the busbar wiring 25_2 on the negative side in the y-axis direction by using lead-free solder 32_2. At this time, for the busbar wirings 25_1 and 25_2, the busbar wiring 25 as shown in Fig. 7 is used, that is, the busbar wiring 25 in which the lead-containing solder 41 is provided on one side 51 in the longitudinal direction of the busbar wiring 25 and the lead-free solder 42 is provided on the other side 52 in the longitudinal direction of the busbar wiring 25. In addition, in this embodiment, the busbar wiring shown in Fig. 8 may be used.

[0058] The solar cell module according to the present embodiment can be manufactured by the manufacturing method described above. Furthermore, by using the solar cell module manufacturing method according to the present embodiment, it is possible to suppress the occurrence of defects in the connection between the electrode terminals and the bus bar wiring.

[0059] <Embodiment 2> Next, a second embodiment of the present invention will be described. Fig. 9 is a front view showing a solar cell module according to the second embodiment. Fig. 10 is a cross-sectional view showing a solar cell module according to the second embodiment, that is, a cross-sectional view of a busbar wiring 24_1. In the second embodiment, a configuration example will be described in which the busbar wiring 24 (see Fig. 9) is wiring having lead-containing solder on the photovoltaic power generation cell side and lead-free solder on the electrode terminal side. In this embodiment, the same components as those in the first embodiment are given the same reference numerals, and duplicated explanations will be omitted.

[0060] As shown in Fig. 9, the solar cell module 2 according to this embodiment includes a tab wiring 22 that connects a plurality of photovoltaic cells 21 to each other, bus bar wirings (first wirings) 24_1, 24_2 connected to the tab wiring 22, and bus bar wirings (second wirings) 25_1, 25_2 connected to the bus bar wirings 24_1, 24_2 and electrode terminals 31_1, 31_2 (see Fig. 5). The tab wiring 22 is soldered to the photovoltaic cells 21 using leaded solder. As described above, the tab wiring 22 is used in large quantities, so productivity needs to be improved. Therefore, a wiring plated with leaded solder is manufactured by a roll-to-roll method, and the plated wiring is cut and used.

[0061] As shown in Fig. 10, lead-containing solder 41 is provided on one side 61_1 in the longitudinal direction of the busbar wiring 24_1, and lead-free solder 42 is provided on the other side 62_1 in the longitudinal direction of the busbar wiring 24_1. In addition, lead-containing solder 41 is provided on the tab wiring 22. Lead-free solder 42 is provided on the busbar wiring 25_1. One side 61_1 of the busbar wiring 24_1 is soldered to the tab wiring 22 by using the lead-containing solder 41. In addition, the other side 62_1 of the busbar wiring 24_1 is soldered to the busbar wiring 25_1 by using the lead-free solder 42.

[0062] Similarly, lead-containing solder 41 is provided on one side 61_2 in the longitudinal direction of the bus bar wiring 24_2, and lead-free solder 42 is provided on the other side 62_2 in the longitudinal direction of the bus bar wiring 24_2. The one side 61_2 of the bus bar wiring 24_2 is soldered to the tab wiring 22 by using the lead-containing solder 41. The other side 62_2 of the bus bar wiring 24_2 is soldered to the bus bar wiring 25_2 by using the lead-free solder 42.

[0063] The bus bar wirings 25_1, 25_2 are soldered to the electrode terminals 31_1, 31_2 (see FIG. 5) using lead-free solders 32_1, 32_2. The rest of the configuration is the same as that described in the first embodiment, so a duplicated description will be omitted.

[0064] In this embodiment, leaded solder is used to connect the photovoltaic power generation cells 21 and the tab wiring 22, while lead-free solder 42 is used to connect the bus bar wirings 24_1, 24_2 and the bus bar wirings 25_1, 25_2. Furthermore, lead-free solders 32_1, 32_2 are used to connect the bus bar wirings 25_1, 25_2 and the electrode terminals 31_1, 31_2. This makes it possible to suppress the occurrence of defects in the wiring connecting the photovoltaic power generation cells 21 and the electrode terminals 31_1, 31_2.

[0065] <Embodiment 3> Next, a third embodiment of the present invention will be described. FIG. 11 is a front view showing a solar cell module according to the third embodiment. FIG. 12 is a cross-sectional view showing a solar cell module according to the third embodiment, taken along the line XII-XII shown in FIG. 11. In the third embodiment, a configuration example will be described in which the tab wirings 71_1 and 71_2 have lead solder on the solar cell side and lead-free solder on the electrode terminal side. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0066] As shown in FIG. 11, the solar cell module 3 according to this embodiment includes tab wiring 22 connecting a plurality of photovoltaic cells 21 to each other, bus bar wiring (first wiring) 24_1, 24_2 connected to the tab wiring 22, and bus bar wiring (second wiring) 25_1, 25_2 connected to the bus bar wiring 24_1, 24_2 and electrode terminals 31_1, 31_2 (see FIG. 5).

[0067] 12, the tab wiring 71_1 of the tab wiring 22 connected to the bus bar wiring 24_1 has lead-containing solder 41 provided on one side in the longitudinal direction (the photovoltaic power generation cell 21 side) and lead-free solder 42 provided on the other side in the longitudinal direction (the bus bar wiring 24_1 side). One side (the photovoltaic power generation cell 21 side) of the tab wiring 71_1 connected to the bus bar wiring 24_1 is soldered to the photovoltaic power generation cell 21 using the lead-containing solder 41, and the other side (the bus bar wiring 24_1 side) is soldered to the bus bar wiring 24_1 using the lead-free solder 42. The tab wiring 22 is soldered to the photovoltaic power generation cell 21 using the lead-containing solder 41 on the surface on the positive side in the z-axis direction of the photovoltaic power generation cell 21.

[0068] Similarly, the tab wiring 71_2 of the tab wiring 22 connected to the bus bar wiring 24_2 has lead-containing solder 41 provided on one side in the longitudinal direction (the photovoltaic power generation cell 21 side) and lead-free solder 42 provided on the other side in the longitudinal direction (the bus bar wiring 24_2 side). One side (the photovoltaic power generation cell 21 side) of the tab wiring 71_2 connected to the bus bar wiring 24_2 is soldered to the photovoltaic power generation cell 21 using the lead-containing solder 41, and the other side (the bus bar wiring 24_2 side) is soldered to the bus bar wiring 24_2 using the lead-free solder 42.

[0069] The bus bar wirings 24_1, 24_2 are soldered to the bus bar wirings 25_1, 25_2 using lead-free solders 72_1, 72_2. The bus bar wirings 25_1, 25_2 are soldered to the electrode terminals 31_1, 31_2 (see FIG. 5) using lead-free solders 32_1, 32_2. The rest of the configuration is the same as that described in the first embodiment, so a duplicated description will be omitted.

[0070] In this embodiment, leaded solder is used to connect the photovoltaic power generation cells 21 and the tab wirings 22, 71, while lead-free solder 42 is used to connect the tab wirings 71_1, 71_2 and the bus bar wirings 24_1, 24_2. Furthermore, lead-free solders 72_1, 72_2 are used to connect the bus bar wirings 24_1, 24_2 and the bus bar wirings 25_1, 25_2. Furthermore, lead-free solders 32_1, 32_2 are used to connect the bus bar wirings 25_1, 25_2 and the electrode terminals 31_1, 31_2. This makes it possible to suppress the occurrence of defects in the wiring connecting the photovoltaic power generation cells 21 and the electrode terminals 31_1, 31_2.

[0071] While the present invention has been described above with reference to the above-described embodiment, the present invention is not limited to the configuration of the above-described embodiment, and naturally includes various modifications, alterations, and combinations that may be made by a person skilled in the art within the scope of the invention as defined in the claims of the present application. [Explanation of symbols]

[0072] 1, 2, 3 Solar Module 10 Laminated glass (transparent plate-shaped components) 11 First glass plate 12 Second Glass Pane 13 Intermediate adhesive layer 20_1~20_4 Photovoltaic cell group 21 Photovoltaic Cell 22, 22_1, 22_2 tab wiring 23, 23_1~23_3 Busbar wiring 24, 24_1, 24_2 Busbar wiring (first wiring) 25, 25_1, 25_2 Busbar wiring (second wiring) 26, 26_1, 26_2 hole 27, 27_1, 27_2 Sealing material 28_1, 28_2 Leaded solder 30 Terminal box 31, 31_1, 31_2 electrode terminal 32, 32_1, 32_2 Lead-free solder 33 Terminal block 34_1, 34_2 output cable 35 Bypass Diode 41 Leaded solder 42 Lead-free solder 71_1, 71_2 Tab wiring 72_1, 72_2 Lead-free solder

Claims

1. A transparent plate-like member; A plurality of photovoltaic cells arranged on the transparent plate-shaped member; a terminal box including electrode terminals electrically connected to the plurality of photovoltaic cells, the plurality of photovoltaic cells are connected to the electrode terminals via a plurality of wirings, The plurality of wirings include wirings having lead-containing solder on the photovoltaic power generation cell side and having lead-free solder on the electrode terminal side. Solar cell module.

2. The plurality of wirings include A first wiring electrically connected to the plurality of photovoltaic cells; a second wiring connected to the first wiring and the electrode terminal; lead-containing solder is provided on one side of the second wiring in a longitudinal direction, and lead-free solder is provided on the other side of the second wiring in the longitudinal direction; the one side of the second wiring is soldered to the first wiring using the lead-containing solder; The other side of the second wiring is soldered to the electrode terminal using the lead-free solder. The solar cell module according to claim 1 .

3. The plurality of wirings include a tab wiring that connects the plurality of photovoltaic cells to each other; A first wiring connected to the tab wiring; a second wiring connected to the first wiring and the electrode terminal; lead-containing solder is provided on one side of the first wiring in a longitudinal direction, and lead-free solder is provided on the other side of the first wiring in the longitudinal direction; the one side of the first wiring is soldered to the tab wiring using the leaded solder, The other side of the first wiring is soldered to the second wiring using the lead-free solder. The solar cell module according to claim 1 .

4. The plurality of wirings include a tab wiring that connects the plurality of photovoltaic cells to each other; A first wiring connected to the tab wiring; a second wiring connected to the first wiring and the electrode terminal; The tab wiring connected to the first wiring among the tab wirings has lead solder provided on one side in a longitudinal direction and lead-free solder provided on the other side in the longitudinal direction, The one side of the tab wiring connected to the first wiring is soldered to the solar power generation cell using the lead-containing solder, and the other side is soldered to the first wiring using the lead-free solder. The solar cell module according to claim 1 .

5. The solar cell module according to any one of claims 1 to 4, wherein the lead-free solder contains tin and silver, and the tin content is 90 mass % or more.

6. 5. The solar cell module according to claim 1, wherein the melting point of the lead-free solder is higher than the melting point of the leaded solder.

7. the transparent plate-like member is a laminated glass including a first glass plate, a second glass plate, and an intermediate adhesive layer disposed between the first glass plate and the second glass plate; the plurality of photovoltaic cells are disposed within the intermediate adhesive layer; The solar cell module according to any one of claims 1 to 4.

8. the second wiring is a ribbon-shaped wiring having a predetermined width, the lead-containing solder is plated on both sides of the second wiring on the one side of the second wiring, the lead-free solder is plated on both sides of the second wiring at the other side of the second wiring; The solar cell module according to claim 2 .

9. the second wiring is a ribbon-shaped wiring having a predetermined width, lead-containing solder is provided on one surface of the second wiring, and lead-free solder is provided on the other surface of the second wiring; a region where no lead-free solder is formed on the other surface of the second wiring is formed on the one side of the second wiring, a region where no lead-containing solder is formed on the one surface of the second wiring is formed on the other side of the second wiring; The solar cell module according to claim 2 .

10. The first wiring is a ribbon-shaped wiring having a predetermined width, the lead-containing solder is plated on both sides of the first wiring on the one side of the first wiring, the lead-free solder is plated on both sides of the first wiring at the other side of the first wiring; The solar cell module according to claim 3 .

11. The first wiring is a ribbon-shaped wiring having a predetermined width, lead-containing solder is provided on one surface of the first wiring, and lead-free solder is provided on the other surface of the first wiring; a region where no lead-free solder is formed on the other surface of the first wiring is formed on the one side of the first wiring, a region where no lead-containing solder is formed on the one surface of the first wiring is formed on the other side of the first wiring; The solar cell module according to claim 3 .

12. The first wiring includes a first bus bar wiring on a positive side and a first bus bar wiring on a negative side, the second wiring includes a positive second bus bar wiring and a negative second bus bar wiring, The electrode terminal includes a positive electrode terminal and a negative electrode terminal, The plurality of photovoltaic cells are connected in series to each other using tab wiring, a positive side of the tab wiring that connects the plurality of photovoltaic power generation cells in series is connected to a first bus bar wiring on the positive side, a negative side of the tab wiring that connects the plurality of photovoltaic power generation cells in series is connected to a first bus bar wiring on the negative side, the first bus bar wiring on the positive side is connected to the positive electrode terminal via the second bus bar wiring on the positive side, the negative-side first bus bar wiring is connected to the negative-side electrode terminal via the negative-side second bus bar wiring; The solar cell module according to any one of claims 2 to 4.

13. Arranging a plurality of photovoltaic cells on a transparent plate-shaped member; a step of disposing a terminal box on the plate-like member; and electrically connecting electrode terminals of the terminal box to the plurality of photovoltaic cells, the plurality of photovoltaic cells are connected to the electrode terminals via a plurality of wirings; The plurality of wirings include wirings having lead-containing solder on the photovoltaic power generation cell side and having lead-free solder on the electrode terminal side. A method for manufacturing a solar cell module.

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