WO2017002287A1 - Solar battery module - Google Patents

Solar battery module Download PDF

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Publication number
WO2017002287A1
WO2017002287A1 PCT/JP2016/002011 JP2016002011W WO2017002287A1 WO 2017002287 A1 WO2017002287 A1 WO 2017002287A1 JP 2016002011 W JP2016002011 W JP 2016002011W WO 2017002287 A1 WO2017002287 A1 WO 2017002287A1
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WO
WIPO (PCT)
Prior art keywords
bus bar
solar cell
bar electrode
tab wiring
longitudinal direction
Prior art date
Application number
PCT/JP2016/002011
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French (fr)
Japanese (ja)
Inventor
平　茂治
翔士 佐藤
直宏 月出
Original Assignee
パナソニックＩｐマネジメント株式会社
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Publication of WO2017002287A1 publication Critical patent/WO2017002287A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/05—Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/548—Amorphous silicon PV cells

Definitions

  • the present invention relates to a solar cell module.
  • solar cell modules are being developed as photoelectric conversion devices that convert light energy into electrical energy.
  • the solar cell module is expected as a new energy source because it can directly convert sunlight into electricity and has a smaller environmental load than clean power generation using fossil fuel.
  • the solar cell module has, for example, a structure in which a plurality of solar cell elements are sealed with a filling member between a surface protection member and a back surface protection member.
  • the plurality of solar cell elements are arranged in a matrix.
  • a plurality of solar cell elements arranged linearly along one of the row direction or the column direction are connected by tab wiring joined to the bus bar electrodes of two adjacent solar cell elements to form a string. ing.
  • Patent Document 1 describes a technique related to such a solar cell module.
  • the bus bar electrode and the tab wiring are uniformly bonded over the entire area of the bus bar electrode in the longitudinal direction of the tab wiring. For this reason, when a solar cell element and a tab wiring repeat expansion and contraction due to a temperature cycle or the like, stress may occur in the solar cell element and the tab wiring.
  • Patent Document 2 discloses a configuration in which a portion of the tab wiring is not connected to the bus bar electrode by solder to relieve stress generated in the solar cell element and the tab wiring and prevent cell cracking or the like.
  • JP 2011-187882 A Japanese Patent No. 4174545
  • the present invention provides a solar cell module capable of reducing the stress of the solar cell element and the tab wiring even when the above-described stress occurs, while increasing the total output within the product life. For the purpose.
  • the solar cell module which concerns on 1 aspect of this invention is equipped with two adjacent solar cell elements, and the elongate tab wiring which electrically connects the said two solar cell elements, These two solar cell elements Each has a long bus bar electrode that is formed along the long direction of the tab wiring and is joined to the tab wiring so as to overlap, and the bus bar electrode is a light-receiving charge generated by the solar cell element.
  • a plurality of openings, and the plurality of openings are provided side by side along the longitudinal direction. Openings with different areas are included.
  • the solar cell module which concerns on 1 aspect of this invention is equipped with two adjacent solar cell elements, and the elongate tab wiring which electrically connects the said two solar cell elements, These two solar cell elements Each has a long bus bar electrode that is formed along the long direction of the tab wiring and is joined to the tab wiring so as to overlap, and the bus bar electrode is a light-receiving charge generated by the solar cell element. And a plurality of openings, the openings being aligned along the longitudinal direction and the intersecting direction intersecting the longitudinal direction in plan view. The number of the plurality of openings provided side by side along the intersecting direction is different along the longitudinal direction.
  • the solar cell module which concerns on 1 aspect of this invention is equipped with two adjacent solar cell elements, and the elongate tab wiring which electrically connects the said two solar cell elements, These two solar cell elements Each has a long bus bar electrode that is formed along the long direction of the tab wiring and is joined to the tab wiring so as to overlap, and the bus bar electrode is a light-receiving charge generated by the solar cell element.
  • the solar cell module according to the present invention it is possible to reduce the stress of the solar cell element and the tab wiring while increasing the total output within the product life.
  • FIG. 1 is a schematic plan view of the solar cell module according to Embodiment 1.
  • FIG. 2 is a plan view of the solar cell element according to Embodiment 1.
  • FIG. 3 is a cross-sectional view illustrating a stacked structure of the solar cell element according to Embodiment 1.
  • 4 is a structural cross-sectional view in the column direction of the solar cell module according to Embodiment 1.
  • FIG. 5 is a plan view showing an example of the configuration of the bus bar electrode according to the first embodiment.
  • FIG. 6 is a plan view showing an example of the configuration of the bus bar electrode according to the first embodiment.
  • FIG. 7 is a plan view showing an example of the configuration of the bus bar electrode according to the first embodiment.
  • FIG. 1 is a schematic plan view of the solar cell module according to Embodiment 1.
  • FIG. 2 is a plan view of the solar cell element according to Embodiment 1.
  • FIG. 3 is a cross-sectional view illustrating a stacked structure of the solar cell element
  • FIG. 8 is a plan view showing an example of the configuration of the bus bar electrode according to the second embodiment.
  • FIG. 9 is a plan view showing an example of the configuration of the bus bar electrode according to the second embodiment.
  • FIG. 10 is a plan view showing an example of the configuration of the bus bar electrode according to the second embodiment.
  • FIG. 11 is a plan view showing an example of the configuration of the bus bar electrode according to the third embodiment.
  • FIG. 12 is a plan view showing an example of the configuration of the bus bar electrode according to the third embodiment.
  • FIG. 13 is a plan view showing an example of the configuration of a bus bar electrode according to a modification of the third embodiment.
  • FIG. 14 is a plan view showing an example of a configuration of a bus bar electrode according to a modification of the third embodiment.
  • FIG. 15 is a schematic diagram for explaining the flow of received light charges in the solar cell element according to Embodiment 3 and its modification.
  • FIG. 16 is a plan view showing an example of the configuration of the bus bar electrode according to the fourth embodiment.
  • FIG. 17 is a plan view showing an example of the configuration of the bus bar electrode according to the fourth embodiment.
  • FIG. 18 is a plan view showing an example of the configuration of the bus bar electrode according to the fourth embodiment.
  • FIG. 19 is a plan view showing an example of a configuration of a bus bar electrode according to another embodiment.
  • FIG. 20 is a plan view showing an example of a configuration of a bus bar electrode according to another embodiment.
  • FIG. 21 is a plan view showing an example of a configuration of a bus bar electrode according to another embodiment.
  • the “front surface” of the solar cell element means, for example, a surface in which more light can enter the interior than the “back surface” that is the opposite surface (light exceeding 50% to 100% light). Is incident on the inside from the front surface), and no light enters the interior from the “back surface” side.
  • the “surface” of the solar cell module means a surface on which light on the side facing the “surface” of the solar cell element can be incident, and the “back surface” means a surface on the opposite side.
  • descriptions such as “providing the second member on the first member” do not intend only when the first and second members are provided in direct contact unless specifically limited. That is, this description includes a case where another member exists between the first and second members.
  • the description of “substantially **” is intended to include not only exactly the same, but also those that are recognized as being substantially the same, with “substantially identical” as an example.
  • Embodiment 1 The solar cell module according to Embodiment 1 will be described with reference to FIGS.
  • FIG. 1 is a schematic plan view of a solar cell module 1 according to Embodiment 1.
  • the solar cell module 1 shown in the figure includes a plurality of solar cell elements 11, a tab wiring 20, a cross wiring 30, and a frame body 60.
  • the solar cell element 11 is a planar photovoltaic cell that is two-dimensionally arranged in a direction parallel to the light receiving surface and generates electric power by light irradiation.
  • the light receiving surface means a surface of a light receiving surface electrode 102 described later.
  • plane view means viewing from a direction perpendicular to the light receiving surface.
  • the tab wiring 20 is a long wiring member that is disposed on one front surface and the other back surface of two adjacent solar cell elements 11 and electrically connects the adjacent solar cell elements 11.
  • the tab wiring 20 electrically connects the solar cell elements 11 adjacent in the column direction, for example, as shown in FIG.
  • the cross wiring 30 is a wiring member for connecting the solar cell strings.
  • the solar cell string is an aggregate of a plurality of solar cell elements 11 arranged in the column direction and connected by the tab wiring 20.
  • the frame body 60 is an outer frame member that covers the outer peripheral portion of the panel in which the plurality of solar cell elements 11 are two-dimensionally arranged.
  • FIG. 2 is a plan view of the solar cell element 11 according to the first embodiment.
  • the solar cell element 11 has a substantially square shape in plan view.
  • the solar cell element 11 is, for example, 125 mm long ⁇ 125 mm wide ⁇ 200 ⁇ m thick.
  • a plurality of striped bus bar electrodes 40 are formed in parallel to each other, and a plurality of striped finger electrodes 50 are formed in parallel to each other so as to be orthogonal to the bus bar electrodes 40.
  • interval of the several finger electrode 50 are not limited to what is shown by FIG.
  • the tab wiring 20 is joined on the bus bar electrode 40 as shown by a dotted line in FIG.
  • the bus bar electrode 40 and the tab wiring 20 have, for example, substantially the same line width.
  • the received light charges generated by the solar cell element 11 are collected by the finger electrode 50.
  • the light-receiving charges collected by the finger electrodes 50 are transmitted to the bus bar electrode 40 and further transmitted to the tab wiring 20 joined immediately above the bus bar electrode 40.
  • the bus bar electrode 40 has an opening as shown in FIG. Details of the opening of the bus bar electrode 40 will be described later.
  • the bus bar electrode 40 and the finger electrode 50 constitute a collector electrode 100.
  • the collector electrode 100 is formed of, for example, a conductive paste containing conductive particles such as Ag (silver). In FIG.
  • hatching is added to the bus bar electrode 40 and the finger electrode 50, but the hatching here is added to distinguish from the opening and does not mean a cross section. Similarly, hatching added to bus bar electrodes and finger electrodes shown in FIGS. 5 to 21 described later does not mean a cross section.
  • FIG. 3 is a cross-sectional view showing the laminated structure of solar cell element 11 according to Embodiment 1.
  • 2 is a cross-sectional view taken along the line III-III of the solar cell element 11 in FIG.
  • an i-type amorphous silicon film 121 and a p-type amorphous silicon film 122 are formed in this order on the main surface of an n-type single crystal silicon wafer 101.
  • the n-type single crystal silicon wafer 101, the i-type amorphous silicon film 121, and the p-type amorphous silicon film 122 form a photoelectric conversion layer, and the n-type single crystal silicon wafer 101 serves as a main power generation layer.
  • the light receiving surface electrode 102 is formed on the p-type amorphous silicon film 122.
  • a collecting electrode 100 including a plurality of bus bar electrodes 40 and a plurality of finger electrodes 50 is formed on the light receiving surface electrode 102. In FIG. 3, only the finger electrode 50 of the collector electrode 100 is shown.
  • an i-type amorphous silicon film 123 and an n-type amorphous silicon film 124 are formed in this order on the back surface of the n-type single crystal silicon wafer 101. Further, the light receiving surface electrode 103 is formed on the n-type amorphous silicon film 124, and the collector electrode 100 including the plurality of bus bar electrodes 40 and the plurality of finger electrodes 50 is formed on the light receiving surface electrode 103.
  • the p-type amorphous silicon film 122 is formed on the back surface side of the n-type single crystal silicon wafer 101 and the n-type amorphous silicon film 124 is formed on the light-receiving surface side of the n-type single crystal silicon wafer 101, respectively. Good.
  • the collector electrode 100 can be formed by a printing method such as screen printing using, for example, a thermosetting resin-type conductive paste using a resin material as a binder and conductive particles such as silver particles as a filler. .
  • the pitch of the finger electrodes 50 on the back surface is the same as the pitch of the finger electrodes 50 on the front surface, but the pitch of the finger electrodes 50 on the back surface is smaller than the pitch of the finger electrodes 50 on the front surface.
  • the number of finger electrodes 50 on the back surface may be larger than the number of finger electrodes 50 on the front surface.
  • the area occupation ratio of the collector electrode 100 formed on the back surface may be higher than the area occupation ratio of the collector electrode formed on the front surface.
  • the area occupation ratio of the collector electrode is a ratio of the total area of the bus bar electrode 40 and the finger electrode 50 in the plan view to the area of the solar cell element 11 in the plan view.
  • the solar cell element 11 according to the present embodiment is a single-sided light receiving type in which the light receiving surface is the front surface, the effect of increasing the current collection efficiency on the back surface is more than the effect of increasing the light shielding loss on the back surface. large. Therefore, the current collection efficiency of the solar cell element 11 can be improved.
  • the solar cell element 11 is provided between the n-type single crystal silicon wafer 101 and the p-type amorphous silicon film 122 or the n-type amorphous silicon film 124 in order to improve the pn junction characteristics.
  • the i-type amorphous silicon film 121 is provided.
  • the solar cell element 11 is a single-sided light receiving type, and the light receiving surface electrode 102 on the surface side of the n-type single crystal silicon wafer 101 serves as a light receiving surface. Carriers generated in the n-type single crystal silicon wafer 101 diffuse as photocurrents to the light-receiving surface electrodes 102 and 103 on the front surface side and the back surface side and are collected by the collector electrode 100.
  • the light receiving surface electrodes 102 and 103 are transparent electrodes made of, for example, ITO (indium tin oxide), SnO 2 (tin oxide), ZnO (zinc oxide), or the like.
  • the light receiving surface electrode 103 on the back side may be a metal electrode that is not transparent.
  • the solar cell element 11 may be a double-sided light receiving type.
  • the light receiving surface electrode 102 on the front surface side and the light receiving surface electrode 103 on the back surface side of the n-type single crystal silicon wafer 101 are light receiving surfaces.
  • Carriers generated in the n-type single crystal silicon wafer 101 diffuse as photocurrents to the light-receiving surface electrodes 102 and 103 on the front surface side and the back surface side and are collected by the collector electrode 100.
  • the light receiving surface electrodes 102 and 103 are transparent electrodes.
  • the solar cell element 11 only needs to have a function as a photovoltaic power, and the structure of the solar cell element 11 is not limited to the above-described structure.
  • FIG. 4 is a structural cross-sectional view of the solar cell module 1 according to Embodiment 1 in the column direction. 4 is a cross-sectional view taken along the line IV-IV in the solar cell module 1 of FIG.
  • the solar cell module 1 shown in the figure includes a solar cell element 11, a tab wiring 20, a surface filling member 70A and a back surface filling member 70B, a surface protection member 80, and a back surface protection member 90.
  • the tab wiring 20 is a long conductive wiring, for example, a ribbon-shaped metal foil.
  • the tab wiring 20 can be produced, for example, by cutting a metal foil such as a copper foil or a silver foil, which is covered with solder, silver, or the like into a strip having a predetermined length.
  • the tab wiring 20 disposed on the surface of one solar cell element 11 is also disposed on the back surface of the other solar cell element 11. More specifically, the lower surface of one end of the tab wiring 20 is joined to the bus bar electrode 40 (not shown in FIG. 4) on the surface side of one solar cell element 11. Further, the upper surface of the other end portion of the tab wiring 20 is joined to a bus bar electrode 40 (not shown in FIG.
  • the solar cell string composed of a plurality of solar cell elements 11 arranged in the column direction has a configuration in which the plurality of solar cell elements 11 are connected in series in the column direction.
  • the tab wiring 20 and the bus bar electrode 40 are joined by, for example, a solder material.
  • a surface protection member 80 is disposed on the surface side of the plurality of solar cell elements 11, and a back surface protection member 90 is disposed on the back surface side.
  • a surface filling member 70 ⁇ / b> A is disposed between the surface including the plurality of solar cell elements 11 and the surface protection member 80, and the back surface filling is performed between the surface including the plurality of solar cell elements 11 and the back surface protection member 90.
  • a member 70B is arranged. The front surface protection member 80 and the back surface protection member 90 are fixed by a front surface filling member 70A and a back surface filling member 70B, respectively.
  • the surface protection member 80 is a protection member disposed on the surface side of the solar cell element 11.
  • the surface protection member 80 is a member that protects the inside of the solar cell module 1 from wind and rain, external impact, fire, and the like, and ensures long-term reliability of the solar cell module 1 when exposed outdoors. From this point of view, the surface protection member 80 can be made of, for example, glass having translucency and water shielding properties, a resin member having a light-transmitting property and water shielding properties such as a film or plate.
  • the back surface protection member 90 is a protection member disposed on the back surface side of the solar cell element 11.
  • the back surface protection member 90 is a member that protects the back surface of the solar cell module 1 from the external environment.
  • a resin film such as polyethylene terephthalate or a laminated film having a structure in which an Al foil is sandwiched between resin films is used. Can do.
  • the front surface filling member 70 ⁇ / b> A is a filler filled in the space between the plurality of solar cell elements 11 and the surface protection member 80
  • the back surface filling member 70 ⁇ / b> B is formed between the plurality of solar cell elements 11 and the back surface protection member 90. It is a filler filled in the space between.
  • the front surface filling member 70A and the back surface filling member 70B have a sealing function for blocking the solar cell element 11 from the external environment. With the arrangement of the front surface filling member 70A and the back surface filling member 70B, it is possible to ensure high heat resistance and high moisture resistance of the solar cell module 1 assumed to be installed outdoors.
  • the surface filling member 70A is made of a translucent polymer material having a sealing function.
  • Examples of the polymer material of the surface filling member 70A include translucent resin materials such as ethylene vinyl acetate (EVA).
  • the back surface filling member 70B is made of a polymer material having a sealing function.
  • the back surface filling member 70B is processed in white.
  • the polymer material of the back surface filling member 70B include a resin material obtained by processing EVA or the like in white.
  • the surface filling member 70A and the back surface filling member 70B are made of the same material system from the viewpoint of simplification of the manufacturing process and the adhesion of the interface between the surface filling member 70A and the back surface filling member 70B.
  • the front surface filling member 70A and the back surface filling member 70B are obtained by laminating (laminating) two resin sheets (translucent EVA sheet and white processed EVA sheet) sandwiching a plurality of solar cell elements 11 (cell strings). It is formed by doing.
  • FIGS. 5 to 7 show a finger electrode 50 in addition to the bus bar electrode 40.
  • the bus bar electrode on at least one of the front and back surfaces of the solar cell element 11 has the configuration of the bus bar electrode 40 shown in FIGS. That is, the bus bar electrode 40 shown in FIGS. 5 to 7 may have only the front surface, the back surface, or both surfaces of the solar cell element 11. The same applies to FIGS. 8 to 14 and FIGS. 16 to 21 described later.
  • the bus bar electrode 40 is a long electrode that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap.
  • the bus bar electrode 40 has a charge transfer portion 41 that transfers the light-receiving charge generated by the solar cell element 11 to the tab wiring 20.
  • the bus bar electrode 40 has a plurality of openings 42. The plurality of openings 42 are provided side by side along the longitudinal direction of the tab wiring 20 (longitudinal direction of the bus bar electrode 40).
  • the longitudinal direction of the tab wiring 20 is also simply referred to as a longitudinal direction.
  • the plurality of openings 42 include openings 42 having different areas in plan view. Specifically, at least the width in the long direction of the openings 42 having different areas among the plurality of openings 42 and the width in the crossing direction (the short direction of the bus bar electrode 40) intersecting the long direction in plan view. One is different.
  • the crossing direction is, for example, a direction substantially perpendicular to the long direction in plan view.
  • the area in planar view of all the plurality of openings 42 may be different.
  • the area of the plurality of openings 42 in plan view may be larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction.
  • the area of the plurality of openings 42 in plan view is larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction.
  • the plurality of openings 42 have the same width in the intersecting direction and different widths in the longitudinal direction.
  • the width in the longitudinal direction of the plurality of openings 42 is larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction.
  • the area in the planar view of the plurality of openings 42 becomes larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction.
  • the area of the plurality of openings 42 in plan view is larger as it is closer to the center of the bus bar electrode 40 in the longitudinal direction.
  • the widths in the intersecting direction of the plurality of openings 42 are the same, and the widths in the longitudinal direction are different.
  • the width in the longitudinal direction of the plurality of openings 42 increases as the distance from the center of the bus bar electrode 40 in the longitudinal direction increases.
  • the area of the plurality of openings 42 in plan view increases as the area is closer to the center of the bus bar electrode 40 in the longitudinal direction.
  • the area of the plurality of openings 42 in plan view is larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction.
  • at least one of the width in the intersecting direction and the width in the longitudinal direction of the plurality of openings 42 is different.
  • the width in the longitudinal direction and the intersecting direction of the opening 42 located near both ends of the bus bar electrode 40 in the longitudinal direction is larger than the width in the longitudinal direction and the intersecting direction of the other opening 42.
  • the width of the other opening portions 42 in the intersecting direction is smaller as it is closer to the center of the bus bar electrode 40 in the longitudinal direction.
  • the area in the planar view of the plurality of openings 42 becomes larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction.
  • the bus bar electrodes 40 are provided side by side along the longitudinal direction, and have a plurality of openings 42 whose area in plan view is non-uniform along the longitudinal direction.
  • the bus bar electrode 40 has regions with different area occupancy rates of the charge transfer portions 41 for the respective regions, such as the first region and the second region shown in FIGS.
  • the area occupancy of the charge transfer unit 41 in the first region is larger than the area occupancy of the charge transfer unit 41 in the second region.
  • the first region and the second region have the same size.
  • the size of the first region and the second region needs to be equal to or larger than a predetermined size.
  • the predetermined size is a size including at least one opening 42.
  • the bus bar electrode 40 is, for example, the bus bar electrode in the longitudinal direction as the central region of the bus bar electrode 40 in the longitudinal direction as in the first region and the second region shown in FIGS. 5 and 7. It has a region where the area occupancy of the charge transfer portion 41 with respect to each region is larger than the regions on both ends of the electrode 40.
  • the bus bar electrode 40 is, for example, as the first region and the second region shown in FIG. 6, the regions on both ends of the bus bar electrode 40 in the longitudinal direction are closer to the center of the bus bar electrode 40 in the longitudinal direction. There are regions in which the area occupancy of the charge transfer portion 41 with respect to each region is larger than the region on the side.
  • first region and the second region are not limited to the regions shown in FIGS. 5 to 7, and may be regions at positions different from the regions shown in FIGS.
  • the solar cell module 1 includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11.
  • Each of the two solar cell elements 11 has a long bus bar electrode 40 that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap.
  • the bus bar electrode 40 has a charge transfer portion 41 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a plurality of openings 42.
  • the plurality of openings 42 are provided side by side along the longitudinal direction, and the plurality of openings 42 include openings 42 having different areas in plan view.
  • the bus bar electrode 40 has regions having different area occupancy rates of the charge transfer portions 41 with respect to the respective regions, for example, the first region and the second region shown in FIGS. That is, the area occupancy rate of the charge transfer portion 41 becomes non-uniform along the longitudinal direction.
  • the bus bar electrode 40 has a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 41 is low (second region) and a region where the adhesive strength is high (first region).
  • the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly.
  • the electrical loss is reduced. That is, in the solar cell module 1 according to Embodiment 1, since the portion where the tab wiring 20 and the bus bar electrode 40 are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 41 is low is peeled off.
  • the stress of the solar cell element 11 and the tab wiring 20 can be reduced thereafter. Further, in the region where the adhesive strength between the tab wiring 20 and the charge transfer portion 41 is high, since the tab wiring 20 and the charge transfer portion 41 are joined, it is possible to suppress a decrease in current collection efficiency. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
  • the bus bar electrode 40 is not joined to the tab wiring 20 at the opening 42. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region that is not joined to the bus bar electrode 40 of the tab wiring 20. The stress on the tab wiring 20 can be reduced.
  • At least one of the width in the longitudinal direction of the opening 42 having a different area among the plurality of openings 42 and the width in the intersecting direction intersecting the longitudinal direction in plan view are different.
  • the area of the plurality of openings 42 in plan view can be changed.
  • the area of the plurality of openings 42 in plan view is larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction.
  • one of the center and both ends of the bus bar electrode 40 in the longitudinal direction can be set to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 40 is low.
  • the tab wiring 20 can be easily peeled off at the central side. Therefore, if the bonding strength between the solar cell element 11 and the tab wiring 20 is high, there is no escape from stress due to temperature cycles or the like, so the stress on the solar cell element 11 is increased, but the tab wiring 20 is peeled off at the center side. The stress on the solar cell element 11 is alleviated.
  • the tab wiring 20 can be easily peeled off at both end sides. Therefore, the degree of freedom at both ends of the tab wiring 20 is increased, so that stress at both ends of the tab wiring 20 can be reduced.
  • the area in plan view of the plurality of openings 42 shown in FIGS. 5 to 7 is larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction, it is not limited thereto.
  • the areas of the plurality of openings 42 in plan view may be different areas, and may not increase in order from one of the center and both ends of the bus bar electrode 40 in the longitudinal direction toward the other. Good. That is, any region of the bus bar electrode 40 may be an area where the adhesive strength between the tab wiring 20 and the bus bar electrode 40 is low, instead of one of the center and both ends of the bus bar electrode 40.
  • the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 41 is low is peeled off. Therefore, the stress can be absorbed in the region where the bonding of the tab wiring 20 with the bus bar electrode 40 is peeled off, so that the stress of the solar cell element 11 and the tab wiring 20 can be reduced.
  • the solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11.
  • Each of the two solar cell elements 11 has a long bus bar electrode 140 that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap.
  • the bus bar electrode 140 includes a charge transfer unit 141 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a plurality of openings 142.
  • FIG. 8 to 10 are plan views showing an example of the configuration of the bus bar electrode 140 according to the second embodiment.
  • the plurality of openings 142 are provided side by side along the longitudinal direction and the crossing direction that intersects the long direction in plan view, and are provided side by side along the crossing direction of the plurality of openings 142.
  • the number obtained varies along the longitudinal direction.
  • the area of the plurality of openings 142 in plan view may be larger as it is closer to either the center or both ends of the bus bar electrode 140 in the longitudinal direction.
  • the number of the plurality of openings 142 provided side by side in the crossing direction may be as large as closer to either the center or both ends of the bus bar electrode 140 in the longitudinal direction.
  • the number of the plurality of openings 142 provided side by side along the intersecting direction is larger as it is closer to both ends of the bus bar electrode 140 in the longitudinal direction.
  • four openings 142 are provided at both ends of the bus bar electrode 140 in the longitudinal direction, and one opening 142 is provided at the center of the bus bar electrode 140 in the longitudinal direction.
  • the area of the opening 142 at both ends of the bus bar electrode 140 in the longitudinal direction in plan view is larger than the area of the other opening 142.
  • the widths of the plurality of openings 142 in the intersecting direction are the same, and the widths of the openings 142 at both ends of the bus bar electrode 140 in the longitudinal direction are the same as the widths of the other openings 142 in the longitudinal direction. Greater than width.
  • the number of the plurality of openings 142 provided side by side along the intersecting direction increases as the distance from the center of the bus bar electrode 140 in the longitudinal direction increases.
  • one opening 142 is provided at both ends of the bus bar electrode 140 in the longitudinal direction, and four openings 142 are provided at the center of the bus bar electrode 140 in the longitudinal direction.
  • the area of the opening 142 at the center of the bus bar electrode 140 in the longitudinal direction in plan view is larger than the areas of the other openings 142.
  • the widths in the intersecting direction of the plurality of openings 142 are the same, and the width in the longitudinal direction of the central opening 142 of the bus bar electrode 140 in the longitudinal direction is the same as the width in the longitudinal direction of the other openings 142. Greater than width.
  • the interval between the two openings 142 adjacent in the cross direction may be larger as the distance from the center of the bus bar electrode 140 in the cross direction is closer.
  • the interval between two adjacent openings 142 close to the center of the bus bar electrode 140 in the intersecting direction is, for example, the width in the intersecting direction of the charge transfer portion 141a shown in FIG.
  • the width in the cross direction of the charge transfer unit 141a is larger than the width in the cross direction of the charge transfer unit 141b arranged along the cross direction with the charge transfer unit 141a.
  • the bus bar electrodes 140 are provided side by side along the longitudinal direction and the crossing direction, and have a plurality of openings 142 in which the number provided side by side along the crossing direction is non-uniform along the longitudinal direction. .
  • the bus bar electrode 140 has regions having different area occupancy rates of the charge transfer portions 141 for the respective regions, such as the first region and the second region shown in FIGS.
  • the area occupation rate of the charge transfer unit 141 in the first region is larger than the area occupation rate of the charge transfer unit 141 in the second region.
  • the first region and the second region have the same size.
  • the size of the first region and the second region needs to be equal to or larger than a predetermined size.
  • the predetermined size is a size including a plurality of openings 142 arranged in the intersecting direction and both ends of the bus bar electrode 140 in the intersecting direction.
  • the bus bar electrode 140 has a bus bar in the longitudinal direction that is closer to the center side of the bus bar electrode 140 in the longitudinal direction, such as the first region and the second region shown in FIGS. 8 and 10. It has a region where the area occupancy of the charge transfer portion 141 with respect to each region is larger than the regions on both ends of the electrode 140.
  • the bus bar electrode 140 is, for example, as the first region and the second region shown in FIG. 9, the regions on both ends of the bus bar electrode 140 in the longitudinal direction are closer to the center of the bus bar electrode 140 in the longitudinal direction. There are regions where the area occupancy of the charge transfer portion 141 for each region is larger than the region on the side.
  • the bus bar electrode 40 has a bus bar in the longitudinal direction that is closer to the center side of the bus bar electrode 140 in the longitudinal direction, such as the first region and the second region shown in FIGS. 8 and 10. It has a region where the area occupancy of the charge transfer portion 141 with respect to each region is larger than the regions on both ends of the electrode 140.
  • the bus bar electrode 140 is, for example, as the first region and the second region shown in FIG. 9, the regions on both ends of the bus bar electrode 140 in the longitudinal direction are closer to the center of the bus bar electrode 140 in the longitudinal direction. There are regions where the area occupancy of the charge transfer portion 141 for each region is larger than the region on the side.
  • first region and the second region are not limited to the regions illustrated in FIGS. 8 to 10 and may be regions at positions different from the regions illustrated in FIGS.
  • the solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11.
  • Each of the two solar cell elements 11 has a long bus bar electrode 140 that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap.
  • the bus bar electrode 140 includes a charge transfer unit 141 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a plurality of openings 142.
  • the plurality of openings 142 are provided side by side along the long direction and the crossing direction intersecting the long direction in plan view, and the number provided along the crossing direction of the plurality of openings 142 is long. Different along the direction.
  • the bus bar electrode 140 has regions having different area occupancy rates of the charge transfer portions 141 for the respective regions, such as the first region and the second region shown in FIGS. That is, the area occupancy of the charge transfer portion 141 becomes non-uniform along the longitudinal direction.
  • the bus bar electrode 140 has a region (second region) where the adhesive strength between the tab wiring 20 and the charge transfer portion 141 is low (second region) and a region (first region).
  • the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly.
  • the solar cell module according to Embodiment 2 since the portion where the tab wiring 20 and the bus bar electrode 140 are not connected is provided unevenly, the electrical loss is reduced.
  • the portion where the tab wiring 20 and the bus bar electrode 140 are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 141 is low is peeled off. Thereby, since stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 140 is peeled off, the stress of the solar cell element 11 and the tab wiring 20 can be reduced thereafter.
  • the tab wiring 20 and the charge transfer portion 141 are joined, it is possible to suppress a decrease in current collection efficiency. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
  • the bus bar electrode 140 is not joined to the tab wiring 20 at the opening 142. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region that is not joined to the bus bar electrode 140 of the tab wiring 20. The stress on the tab wiring 20 can be reduced.
  • the number of the plurality of openings 142 provided side by side along the crossing direction increases as the distance from the center and both ends of the bus bar electrode 140 in the longitudinal direction increases.
  • the area of the plurality of openings 142 in plan view is larger as it is closer to either the center or both ends of the bus bar electrode 140 in the longitudinal direction.
  • one of the center and both ends of the bus bar electrode 140 in the longitudinal direction can be an area where the adhesive strength between the tab wiring 20 and the bus bar electrode 140 is low.
  • the tab wiring 20 can be easily peeled off at the central side. Therefore, if the bonding strength between the solar cell element 11 and the tab wiring 20 is high, there is no escape from stress due to temperature cycles or the like, so the stress on the solar cell element 11 is increased, but the tab wiring 20 is peeled off at the center side. The stress on the solar cell element 11 is alleviated.
  • the tab wiring 20 can be easily peeled off at both end sides. Therefore, the degree of freedom at both ends of the tab wiring 20 is increased, so that stress at both ends of the tab wiring 20 can be reduced.
  • the number of the plurality of openings 142 shown in FIGS. 8 to 10 provided side by side along the crossing direction is closer to one of the center and both ends of the bus bar electrode 140 in the longitudinal direction, the number is larger. Not limited to this.
  • the number of the plurality of openings 142 provided side by side along the intersecting direction may be different along the longitudinal direction, from one of the center and both ends of the bus bar electrode 140 in the longitudinal direction to the other. It does not have to increase in order. That is, any area of the bus bar electrode 140 may be an area where the adhesive strength between the tab wiring 20 and the bus bar electrode 140 is low, instead of one of the center and both ends of the bus bar electrode 140.
  • the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 141 is low is peeled off. Therefore, the stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 140 is peeled off, so that the stress of the solar cell element 11 and the tab wiring 20 can be reduced.
  • the distance between the two openings 142 adjacent in the crossing direction is larger as the distance from the center of the bus bar electrode 140 in the crossing direction is closer.
  • the solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11.
  • Each of the two solar cell elements 11 has a long bus bar electrode 240 that is formed along the lengthwise direction of the tab wiring 20 and overlaps and is joined to the tab wiring 20.
  • the bus bar electrode 240 includes a charge transfer unit 241 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a charge transfer unit in a plurality of regions that are aligned along the crossing direction that intersects the long direction in plan view. And an opening 242 for branching 241.
  • the region branched in the crossing direction by the opening 242 in the charge transfer portion 241 is referred to as a branch portion 241a.
  • FIG. 1 Configuration of Bus Bar Electrode According to Embodiment 3
  • 11 and 12 are plan views showing an example of the configuration of the bus bar electrode 240 according to the third embodiment.
  • the charge transfer portion 241 is branched into a plurality of branch portions 241 a arranged along the crossing direction by the opening 242.
  • the charge transfer portion 241 is branched into two branch portions 241 a arranged along the crossing direction by the opening 242.
  • the opening 242 may be a notch provided at at least one end of both ends of the bus bar electrode 240 in the longitudinal direction.
  • variety of the crossing direction of the branch part 241a changes along a elongate direction. Note that the width of the branching portion 241a in the intersecting direction may increase from one of the center and both ends of the bus bar electrode 240 in the longitudinal direction toward the other.
  • the bus bar electrode 240 is provided with one opening 242.
  • the opening 242 is provided so that the width in the intersecting direction of the branching portion 241 a increases from the center of the bus bar electrode 240 in the longitudinal direction toward both ends.
  • the opening 342 has a shape that tapers from the center of the bus bar electrode 240 toward both ends in the longitudinal direction.
  • the branch part 241a has a reverse taper shape in which the width in the intersecting direction of the branch part 241a increases from the center of the bus bar electrode 240 toward both ends in the longitudinal direction.
  • the bus bar electrode 240 is provided with openings 242 as notches at both ends of the bus bar electrode 240 in the longitudinal direction.
  • the opening 242 is provided such that the width of the branching portion 241a in the crossing direction increases from both ends of the bus bar electrode 240 toward the center in the longitudinal direction.
  • the opening 242 has a shape that tapers from both ends of the bus bar electrode 240 toward the center in the longitudinal direction.
  • the branch part 241a has a reverse taper shape in which the width in the crossing direction of the branch part 241a increases from both ends of the bus bar electrode 240 toward the center in the longitudinal direction.
  • the bus bar electrode 240 has the opening 242 whose width in the crossing direction is not uniform along the longitudinal direction.
  • the bus bar electrode 240 has a branch portion 241a whose width in the intersecting direction is not uniform along the longitudinal direction.
  • the bus bar electrode 240 has regions having different area occupancy rates of the charge transfer portions 241 for the respective regions, such as the first region and the second region illustrated in FIGS. 11 and 12, for example.
  • the area occupancy of the charge transfer unit 241 in the first region is larger than the area occupancy of the charge transfer unit 241 in the second region.
  • the first region and the second region have the same size.
  • the size of the first region and the second region needs to be equal to or larger than a predetermined size.
  • the predetermined size is a size including a part of the opening 242 and both ends of the bus bar electrode 240 in the crossing direction.
  • the width of the branching portion 241a in the crossing direction increases from one of the center and both ends of the bus bar electrode 240 in the long direction toward the other.
  • the bus bar electrode 240 is, for example, the first region on both ends of the bus bar electrode 240 in the longitudinal direction as in the first region and the second region shown in FIG.
  • the region having a larger area occupancy ratio of the charge transfer portion 241 for each region than the second region on the center side of the electrode 240 is provided.
  • the bus bar electrode 240 is, for example, the first region on the central side of the bus bar electrode 240 in the longitudinal direction as in the first region and the second region shown in FIG.
  • the area occupying area of the charge transfer portion 241 with respect to each region is larger than the second regions on both ends of 240.
  • first region and the second region are not limited to the regions illustrated in FIGS. 11 and 12, and may be regions at positions different from the regions illustrated in FIGS. 11 and 12.
  • FIG. 13 and 14 are plan views showing an example of the configuration of the bus bar electrode 240a according to a modification of the third embodiment.
  • the configuration of the bus bar electrode 240a according to the present modification is different from the configuration of the bus bar electrode 240 shown in FIGS. 11 and 12 in that three or more branch portions 241a are arranged along the crossing direction.
  • branch portions 241a are arranged along the crossing direction.
  • the opening 242 has a shape that branches the charge transfer part 241 into four branch parts 241a arranged along the crossing direction at both ends of the opening 242 in the longitudinal direction. .
  • the opening 242 three portions that taper from the center of the bus bar electrode 240 toward both ends in the longitudinal direction are arranged along the crossing direction at each of both ends of the opening 242 in the longitudinal direction.
  • the four branch portions 241a arranged along the cross direction have reverse tapered shapes such that the width of the branch portion 241a in the cross direction increases from the center of the bus bar electrode 240 toward both ends in the longitudinal direction.
  • the opening 242 may have a shape that branches the charge transfer portion 241 into three or five or more branch portions 241a arranged along the crossing direction.
  • the opening portion 242 has two portions that taper from the center of the bus bar electrode 240 in the longitudinal direction toward both ends at each of both ends of the opening portion 242 in the longitudinal direction. It may have a shape of four or more.
  • the three or five or more branch portions 241a arranged along the intersecting direction have a reverse taper such that the width of the branch portion 241a in the intersecting direction increases from the center of the bus bar electrode 240 toward both ends in the longitudinal direction. You may have a shape.
  • the charge transfer portion 241 extends along the cross direction by two openings (notches) 242 arranged along the cross direction at each of both ends of the bus bar electrode 240a in the longitudinal direction.
  • the two openings 242 aligned along the intersecting direction have a shape that tapers from both ends of the bus bar electrode 240 toward the center in the longitudinal direction.
  • the three branch portions 241a arranged along the cross direction have reverse tapered shapes such that the width of the branch portion 241a in the cross direction increases from both ends of the bus bar electrode 140 toward the center in the longitudinal direction.
  • the opening 242 is formed along the cross direction in order to branch the charge transfer portion 241 into four or more branch portions 241a arranged along the cross direction at both ends of the bus bar electrode 240a in the longitudinal direction. Two or more may be provided. Specifically, at each of both ends of the bus bar electrode 240a in the longitudinal direction, there are three openings 242 having a shape that tapers from both ends of the bus bar electrode 240a in the longitudinal direction toward the center. You may provide so that it may line up. As a result, the four or more branch portions 241a arranged along the intersecting direction have a reverse taper shape in which the width of the intersecting direction of the branch portion 241a increases from both ends of the bus bar electrode 240 toward the center in the longitudinal direction. May be.
  • the width in the crossing direction of the bus bar electrode 240a may change along the longitudinal direction.
  • the bus bar electrode 240a may have a reverse tapered shape that increases from both ends of the bus bar electrode 240a in the longitudinal direction toward the center.
  • the bus bar electrode 240a has three or more branching portions 241a whose width in the crossing direction changes along the longitudinal direction so as to be arranged in the crossing direction. Even when the bus bar electrode 240a has three or more branching portions 241a arranged in the crossing direction, the bus bar electrode 240a is, for example, as shown in FIGS. Like the first region and the second region shown, there are regions where the area occupancy rates of the charge transfer portions 241 with respect to the respective regions are different.
  • the solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11.
  • Each of the two solar cell elements 11 has a long bus bar electrode 240 (240a) that is formed along the lengthwise direction of the tab wiring 20 and overlaps and is joined to the tab wiring 20.
  • a plurality of bus bar electrodes 240 (240a) are arranged along a crossing direction, which is a direction crossing the long direction in a plan view, with a charge transfer unit 241 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20.
  • the branch portion 241a has an opening 242 for branching the charge transfer portion 241. The width of the branching portion 241a in the intersecting direction changes along the longitudinal direction.
  • the bus bar electrode 240 (240a) has regions having different area occupancy rates of the charge transfer portions 241 for the respective regions, such as the first region and the second region shown in FIGS. . That is, the area occupation ratio of the charge transfer portion 241 becomes non-uniform along the long direction.
  • the bus bar electrode 240 (240a) includes a region (second region) where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low (second region) and a region (first region).
  • the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly.
  • the electrical loss is reduced. That is, in the solar cell module according to Embodiment 3, since the portion where the tab wiring 20 and the bus bar electrode 240 (240a) are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 241 is low is peeled off.
  • the bus bar electrode 240 (240a) is not joined to the tab wiring 20 at the opening 242. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region of the tab wiring 20 that is not joined to the bus bar electrode 240 (240a). The stress of the element 11 and the tab wiring 20 can be reduced. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
  • the opening 242 branches, for example, the charge transfer portion 241 into the branch portions 241a arranged in the three or more directions along the crossing direction. As a result, the opening 242 branches the charge transfer portion 241 finely, so that the area where the tab wiring 20 and the charge transfer portion 241 are joined increases. Therefore, it is possible to suppress a decrease in current collection efficiency.
  • the opening 242 is a notch provided at at least one end of both ends of the bus bar electrode 240 in the longitudinal direction.
  • the bus bar electrode 240 (240a) is formed in, for example, the first region and the second region shown in FIGS. As described above, there are regions in which the area occupancy ratios of the charge transfer portions 241 with respect to the respective regions are different. That is, the area occupation ratio of the charge transfer portion 241 becomes non-uniform along the long direction.
  • the bus bar electrode 240 (240a) includes a region (second region) where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low (second region) and a region (first region).
  • the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low is peeled off. The stress on the tab wiring 20 can be reduced.
  • the width of the branching portion 241a in the intersecting direction increases from one of the center and both ends of the bus bar electrode 240 (240a) in the longitudinal direction toward the other.
  • either one of the center and both ends of the bus bar electrode 240 (240a) in the longitudinal direction can be set to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 240 (240a) is low.
  • the tab wiring 20 can be easily peeled off at the central side. it can. Therefore, if the bonding strength between the solar cell element 11 and the tab wiring 20 is high, there is no escape from stress due to temperature cycles or the like, so the stress on the solar cell element 11 is increased, but the tab wiring 20 is peeled off at the center side. The stress on the solar cell element 11 is alleviated.
  • the tab wiring 20 is easily peeled off at both ends. be able to. Therefore, the degree of freedom at both ends of the tab wiring 20 is increased, so that stress at both ends of the tab wiring 20 can be reduced.
  • FIG. 15 is a schematic diagram for explaining the flow of received light charges in the solar cell element 11 according to Embodiment 3 and its modification.
  • FIG. 15 is a view as seen from XV-XV in the bus bar electrode 140 of FIG. However, FIG. 15 also shows the configuration around the bus bar electrode 240. Further, the arrows shown in FIG. 15 indicate the flow of received light charges, and the thicker the arrows, the greater the amount of received light charges.
  • the received charge generated in the solar cell element 11 is collected by the finger electrode 50.
  • the light-receiving charges collected by the finger electrode 50 are transmitted to the bus bar electrode 240 and further transmitted to the tab wiring 20 joined immediately above the bus bar electrode 240.
  • the received charge generated in the solar cell element 11 is collected by the finger electrode 50.
  • the received charge collected by the finger electrode 50 is transmitted to the bus bar electrode 240.
  • the received light charge transmitted to the bus bar electrode 240 flows through the bus bar electrode 240 to a position where the tab wiring 20 and the bus bar electrode 240 are not peeled off.
  • the received charge transmitted to the bus bar electrode 240 flows through the bus bar electrode 240 to a portion where the tab wiring 20 and the bus bar electrode 240 are not peeled off while the received charge collected by each finger electrode is added.
  • the amount of received light charges increases each time the bus bar electrode 240 and the finger electrode 50 intersect. Therefore, the greater the amount of received light charge, the greater the power loss due to the resistance component of the bus bar electrode 240.
  • the width of the branching portion 241a in the crossing direction is increased from one of the center and both ends of the bus bar electrode 240 (240a) in the long direction toward the other.
  • the resistance value per unit length of the bus bar electrode 240 (240a) can be decreased from one of the center and both ends of the bus bar electrode 240 (240a) toward the other.
  • the width of the branching portion 241a in the intersecting direction is increased from both ends of the bus bar electrode 240 in the longitudinal direction toward the center (W1 ⁇ W2 ⁇ W3).
  • the resistance value per unit length of the bus bar electrode 240 decreases from the both ends of the bus bar electrode 240 in the longitudinal direction toward the center.
  • the width of the branching portion 241a shown in FIGS. 11 to 14 is increased from one of the center and both ends of the bus bar electrode 240 toward the other in the longitudinal direction, but is not limited thereto. .
  • the width in the intersecting direction of the branch portion 241a only needs to change along the longitudinal direction, and does not increase from one of the center and both ends of the bus bar electrode 240 (240a) in the longitudinal direction toward the other. May be. That is, the adhesive strength between the tab wiring 20 and the bus bar electrode 240 (240a) is low in any region of the bus bar electrode 240 (240a), not in one of the center and both ends of the bus bar electrode 240 (240a). It may be an area.
  • the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low is peeled off. Therefore, the stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 240 (240a) is peeled off, so that the stress of the solar cell element 11 and the tab wiring 20 can be reduced.
  • the width of the bus bar electrode 240 (240a) in the intersecting direction changes along the longitudinal direction.
  • the width of the bus bar electrode 240 (240a) in the crossing direction that is, the width between the upper end and the lower end in the crossing direction of the charge transfer unit 241 is changed along the longitudinal direction, thereby forming the shape of the opening 242. Even without changing, it is possible to create a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low and a region where it is high.
  • the structure of the solar cell module according to the present embodiment and the structure of the solar cell element 11 are the same as those according to the third embodiment, a detailed description thereof will be omitted, and hereinafter, different from the third embodiment. The description will focus on the bus bar electrode 340.
  • the bus bar electrode 340 has a plurality of openings 342.
  • the openings 342 are provided side by side along the longitudinal direction. Note that the width of the branching portion 341a in the intersecting direction may increase from one of the center and both ends of the opening 342 in the longitudinal direction toward the other.
  • the bus bar electrode 340 is provided with four openings 342 similar to the shape of the opening 242 shown in FIGS. 11 and 13 along the longitudinal direction.
  • the opening 342 is provided such that the width in the intersecting direction of the branching portion 341 a increases from both ends of the opening 342 in the longitudinal direction toward the center.
  • the opening 342 has a shape that tapers from the center of the opening 342 in the longitudinal direction toward both ends.
  • the bus bar electrode 340 has, for each opening 342, a branching part 341a having a reverse taper shape in which the width in the crossing direction of the branching part 341a increases from the center of the opening 342 toward both ends in the longitudinal direction. .
  • the bus bar electrode 340 is provided with four circular openings 342.
  • the openings 342 are provided side by side along the longitudinal direction, and the opening 342 has a circular shape, so that the width in the intersecting direction of the branching part 341 a is the opening in the longitudinal direction. It is provided so as to increase from both ends of 342 toward the center.
  • the bus bar electrode 340 has, for each opening 342, a branching part 341a having a reverse tapered shape such that the width of the branching part 341a in the crossing direction increases from the center of the opening 342 toward both ends in the longitudinal direction. .
  • the bus bar electrode 340 has a plurality of openings 342 whose width in the intersecting direction is not uniform along the longitudinal direction.
  • the bus bar electrode 340 has a plurality of branch portions 341a whose width in the crossing direction is not uniform along the longitudinal direction.
  • the bus bar electrode 340 includes regions having different area occupancy rates of the charge transfer portions 341 for the respective regions, such as the first region and the second region illustrated in FIGS.
  • the area occupancy of the charge transfer unit 341 in the first region is larger than the area occupancy of the charge transfer unit 341 in the second region.
  • the first region and the second region have the same size.
  • the size of the first region and the second region needs to be equal to or larger than a predetermined size.
  • the predetermined size is a size including a part of the opening 342 and both ends of the bus bar electrode 340 in the crossing direction.
  • the width of the branching portion 341a in the intersecting direction increases from one of the center and both ends of the opening 342 in the longitudinal direction toward the other.
  • the bus bar electrode 340 is formed so that the first region on both ends of the opening 342 in the longitudinal direction is longer in the longitudinal direction, such as the first region and the second region shown in FIGS.
  • the area occupying area of the charge transfer portion 341 in each region is larger than the second region on the center side of the opening 342 in FIG.
  • first region and the second region are not limited to the regions illustrated in FIGS. 16 to 18 and may be regions at positions different from the regions illustrated in FIGS.
  • the width in the crossing direction of the branching portion 341a shown in FIGS. 16 to 18 increases from one of the center and both ends of the opening 342 in the longitudinal direction toward the other, but is not limited thereto.
  • the width in the intersecting direction of the branching portion 341a only needs to change along the longitudinal direction, and does not have to increase from one of the center and both ends of the opening 342 in the longitudinal direction toward the other. .
  • the four openings 342 are provided side by side along the longitudinal direction, the present invention is not limited to this.
  • two, three, or five or more openings 342 may be provided along the longitudinal direction.
  • the bus bar electrode 340 has a plurality of openings 342, and the openings 342 are provided along the longitudinal direction.
  • the bus bar electrode 340 includes regions having different area occupancy rates of the charge transfer portions 341 for the respective regions, such as the first region and the second region shown in FIGS. That is, the area occupation ratio of the charge transfer portion 341 becomes non-uniform along the long direction.
  • the bus bar electrode 340 has a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 341 is low (second region) and a region where the adhesive strength is high (first region).
  • the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly.
  • the electrical loss is reduced. That is, in the solar cell module according to Embodiment 4, since the portion where the tab wiring 20 and the bus bar electrode 340 are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 341 is low is peeled off.
  • the bus bar electrode 340 is not joined to the tab wiring 20 in the opening 342. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region that is not joined to the bus bar electrode 340 of the tab wiring 20. The stress on the tab wiring 20 can be reduced.
  • the width in the crossing direction of the branching portion 341a increases from one of the center and both ends of the opening 342 in the longitudinal direction toward the other.
  • either the center or both ends of the opening 342 in the longitudinal direction can be set to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 340 is low.
  • the finger electrode 50 is not provided so as to penetrate the bus bar electrode, but is not limited thereto.
  • the bus bar electrode 440 may be penetrated like a finger electrode 350 shown in FIGS. 19 to 21 described below.
  • 19 to 21 are plan views showing an example of the configuration of the bus bar electrode 440 according to another embodiment.
  • FIG. 19 shows a bus bar electrode 440 having a configuration in which the finger electrode 450 penetrates the bus bar electrode 240a shown in FIG. 13 in the crossing direction. Thereby, the finger electrode 450 cuts the opening 442 vertically in the crossing direction.
  • FIG. 20 shows a bus bar electrode 440 having a configuration in which the finger electrode 450 penetrates the bus bar electrode 240a shown in FIG. 14 in the crossing direction. Thereby, the finger electrode 450 cuts the opening 442 vertically in the crossing direction.
  • FIG. 21 shows a bus bar electrode 440 having a configuration in which the finger electrode 450 penetrates the bus bar electrode 340 shown in FIG. 17 in the crossing direction. Thereby, the finger electrode 450 cuts the opening 442 vertically in the crossing direction.
  • branch portions 241 a and 341 a that are not directly connected to the finger electrode 50, but in FIGS. 19 to 21, all the branch portions 441 a are directly connected to the finger electrode 450. . Therefore, in the region where the tab wiring 20 and the bus bar electrode 440 are peeled off, the received charge is distributed to the plurality of branch portions 441a in consideration of the power loss due to the resistance component. Loss can be further suppressed. Further, the area occupation ratio of the charge transfer portion 441 is non-uniform along the longitudinal direction. In other words, the bus bar electrode 440 has a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 441 is low and a region where the adhesive strength is high.
  • the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly.
  • the portion where the tab wiring 20 and the bus bar electrode 440 are not connected is provided unevenly, the electrical loss is reduced. That is, in the solar cell module according to the other embodiment, the portion where the tab wiring 20 and the bus bar electrode 440 are not connected is reduced depending on the location, so that the electrical loss is reduced.
  • the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer
  • the tab wiring 20 in the region where the adhesive strength with the portion 441 is low is peeled off.
  • the width in the cross direction of the bus bar electrode 240a shown in FIG. 14 changes along the longitudinal direction.
  • the width in the cross direction of other bus bar electrodes is not limited to this. It may change along the scale direction.
  • the finger electrode 50 is a straight line, but may not be a straight line, but may be a curved line.
  • the configuration of the solar cell module is a configuration in which a plurality of solar cell elements 11 are arranged in a matrix on the surface, but is not limited to the matrix configuration.
  • the configuration of the solar cell module may be an annular arrangement or a one-dimensional linear or curved arrangement.
  • the present invention can be realized by any combination of the components and functions in the above-described embodiment without departing from the gist of the present invention, and forms obtained by making various modifications conceived by those skilled in the art. Forms are also included in the present invention.

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Abstract

A solar battery module (1) comprises two adjacent solar battery elements (11) and a long tab wire (20) for electrically connecting the two solar battery elements (11). Each of the two solar battery elements (11) is formed along the lengthwise direction of the tab wire (20) and has a long busbar electrode (40) that overlaps and is joined to the tab wire (20). The busbar electrode (40) includes: a charge-transmitting part (41) which transmits, to the tab wire (20), a photo-reception charge generated by the solar battery element (11); and a plurality of openings (42). The plurality of openings (42) are disposed in a row in a lengthwise direction, and the plurality of openings (42) include openings (42) having different surface areas in the planar view.

Description

太陽電池モジュールSolar cell module
　本発明は、太陽電池モジュールに関する。 The present invention relates to a solar cell module.
　従来、光エネルギーを電気エネルギーに変換する光電変換装置として、太陽電池モジュールの開発が進められている。太陽電池モジュールは、太陽光を直接電気に変換できることから、また、化石燃料による発電と比べて環境負荷が小さくクリーンであることから、新しいエネルギー源として期待されている。 Conventionally, solar cell modules are being developed as photoelectric conversion devices that convert light energy into electrical energy. The solar cell module is expected as a new energy source because it can directly convert sunlight into electricity and has a smaller environmental load than clean power generation using fossil fuel.
　太陽電池モジュールは、例えば、表面保護部材と裏面保護部材との間に複数の太陽電池素子が充填部材で封止された構造となっている。太陽電池モジュールにおいて、複数の太陽電池素子は、マトリクス状に配置されている。行方向又は列方向の一方に沿って直線状に配列された複数の太陽電池素子は、隣り合う２つの太陽電池素子どうしのバスバー電極に接合されたタブ配線によって連結されていき、ストリングを構成している。特許文献１には、このような太陽電池モジュールに関する技術が記載されている。 The solar cell module has, for example, a structure in which a plurality of solar cell elements are sealed with a filling member between a surface protection member and a back surface protection member. In the solar cell module, the plurality of solar cell elements are arranged in a matrix. A plurality of solar cell elements arranged linearly along one of the row direction or the column direction are connected by tab wiring joined to the bus bar electrodes of two adjacent solar cell elements to form a string. ing. Patent Document 1 describes a technique related to such a solar cell module.
　ところで、特許文献１に記載の太陽電池モジュールでは、バスバー電極とタブ配線とが、タブ配線の長尺方向におけるバスバー電極の全域にわたり一様に接着されている。このため、温度サイクル等により太陽電池素子及びタブ配線が膨張及び収縮を繰り返すと、太陽電池素子及びタブ配線にストレスが生じる可能性がある。 Incidentally, in the solar cell module described in Patent Document 1, the bus bar electrode and the tab wiring are uniformly bonded over the entire area of the bus bar electrode in the longitudinal direction of the tab wiring. For this reason, when a solar cell element and a tab wiring repeat expansion and contraction due to a temperature cycle or the like, stress may occur in the solar cell element and the tab wiring.
　そこで、特許文献２には、バスバー電極にタブ配線が一部半田で接続されない部分を作り、太陽電池素子及びタブ配線に生じるストレスを緩和してセル割れなどを防ぐ構成が開示されている。 Therefore, Patent Document 2 discloses a configuration in which a portion of the tab wiring is not connected to the bus bar electrode by solder to relieve stress generated in the solar cell element and the tab wiring and prevent cell cracking or the like.
特開２０１１－１８７８８２号公報JP 2011-187882 A 特許第４１７４５４５号公報Japanese Patent No. 4174545
　しかしながら、特許文献２における太陽電池モジュールの構成においては、バスバー電極とタブ配線とが接続されていない部分が一様に存在することから、セル割れなどの不具合が発生していない状態であっても、バスバー電極とタブ配線とが接続されていない部分の電気的ロスによってモジュール出力が低下する。したがって、セル割れなどの不具合は常に発生する訳ではないので、不具合が発生していない場合にはタブ配線とバスバー電極とが接続する部分を増やすことで電気的ロスを低減し、万が一ストレスなどでセル割れなどの不具合が発生するような状況になった場合に、ストレスを緩和する構造に変化させることができた方が良い。 However, in the configuration of the solar cell module in Patent Document 2, since there is a portion where the bus bar electrode and the tab wiring are not connected uniformly, even if there is no problem such as cell cracking. The module output is reduced due to the electrical loss of the portion where the bus bar electrode and the tab wiring are not connected. Therefore, defects such as cell cracks do not always occur, so if there are no defects, increase the portion where the tab wiring and bus bar electrode are connected to reduce the electrical loss. It is better to be able to change the structure to relieve stress when a situation such as a cell crack occurs.
　そこで、本発明は、商品寿命内でのトータルの出力を高めた上で、上記の様なストレスが生じた場合でも太陽電池素子及びタブ配線のストレスを低減することができる太陽電池モジュールを提供することを目的とする。 Therefore, the present invention provides a solar cell module capable of reducing the stress of the solar cell element and the tab wiring even when the above-described stress occurs, while increasing the total output within the product life. For the purpose.
　本発明の一態様に係る太陽電池モジュールは、隣り合う２つの太陽電池素子と、前記２つの太陽電池素子を電気的に接続する長尺状のタブ配線と、を備え、前記２つの太陽電池素子のそれぞれは、前記タブ配線の長尺方向に沿って形成され、前記タブ配線と重なって接合する長尺状のバスバー電極を有し、前記バスバー電極は、前記太陽電池素子で生成された受光電荷を前記タブ配線に伝達する電荷伝達部と、複数の開口部とを有し、前記複数の開口部は、前記長尺方向に沿って並んで設けられ、前記複数の開口部には、平面視における面積が異なる開口部が含まれる。 The solar cell module which concerns on 1 aspect of this invention is equipped with two adjacent solar cell elements, and the elongate tab wiring which electrically connects the said two solar cell elements, These two solar cell elements Each has a long bus bar electrode that is formed along the long direction of the tab wiring and is joined to the tab wiring so as to overlap, and the bus bar electrode is a light-receiving charge generated by the solar cell element. A plurality of openings, and the plurality of openings are provided side by side along the longitudinal direction. Openings with different areas are included.
　本発明の一態様に係る太陽電池モジュールは、隣り合う２つの太陽電池素子と、前記２つの太陽電池素子を電気的に接続する長尺状のタブ配線と、を備え、前記２つの太陽電池素子のそれぞれは、前記タブ配線の長尺方向に沿って形成され、前記タブ配線と重なって接合する長尺状のバスバー電極を有し、前記バスバー電極は、前記太陽電池素子で生成された受光電荷を前記タブ配線に伝達する電荷伝達部と、複数の開口部とを有し、前記複数の開口部は、前記長尺方向及び当該長尺方向と平面視において交差する交差方向に沿って並んで設けられ、前記複数の開口部の前記交差方向に沿って並んで設けられる数は、前記長尺方向に沿って異なる。 The solar cell module which concerns on 1 aspect of this invention is equipped with two adjacent solar cell elements, and the elongate tab wiring which electrically connects the said two solar cell elements, These two solar cell elements Each has a long bus bar electrode that is formed along the long direction of the tab wiring and is joined to the tab wiring so as to overlap, and the bus bar electrode is a light-receiving charge generated by the solar cell element. And a plurality of openings, the openings being aligned along the longitudinal direction and the intersecting direction intersecting the longitudinal direction in plan view. The number of the plurality of openings provided side by side along the intersecting direction is different along the longitudinal direction.
　本発明の一態様に係る太陽電池モジュールは、隣り合う２つの太陽電池素子と、前記２つの太陽電池素子を電気的に接続する長尺状のタブ配線と、を備え、前記２つの太陽電池素子のそれぞれは、前記タブ配線の長尺方向に沿って形成され、前記タブ配線と重なって接合する長尺状のバスバー電極を有し、前記バスバー電極は、前記太陽電池素子で生成された受光電荷を前記タブ配線に伝達する電荷伝達部と、前記長尺方向と平面視において交差する交差方向に沿って並ぶ複数の分岐部に当該電荷伝達部を分岐させる開口部とを有し、前記分岐部の前記交差方向の幅は、前記長尺方向に沿って変化する。 The solar cell module which concerns on 1 aspect of this invention is equipped with two adjacent solar cell elements, and the elongate tab wiring which electrically connects the said two solar cell elements, These two solar cell elements Each has a long bus bar electrode that is formed along the long direction of the tab wiring and is joined to the tab wiring so as to overlap, and the bus bar electrode is a light-receiving charge generated by the solar cell element. A charge transfer portion for transferring the charge transfer portion to the tab wiring, and an opening for branching the charge transfer portion into a plurality of branch portions arranged in a crossing direction intersecting the longitudinal direction in plan view, the branch portion The width in the crossing direction varies along the longitudinal direction.
　本発明に係る太陽電池モジュールによれば、商品寿命内でのトータルの出力を高めた上で、太陽電池素子及びタブ配線のストレスを低減することができる。 According to the solar cell module according to the present invention, it is possible to reduce the stress of the solar cell element and the tab wiring while increasing the total output within the product life.
図１は、実施の形態１に係る太陽電池モジュールの概観平面図である。1 is a schematic plan view of the solar cell module according to Embodiment 1. FIG. 図２は、実施の形態１に係る太陽電池素子の平面図である。2 is a plan view of the solar cell element according to Embodiment 1. FIG. 図３は、実施の形態１に係る太陽電池素子の積層構造を表す断面図である。FIG. 3 is a cross-sectional view illustrating a stacked structure of the solar cell element according to Embodiment 1. 図４は、実施の形態１に係る太陽電池モジュールの列方向における構造断面図である。4 is a structural cross-sectional view in the column direction of the solar cell module according to Embodiment 1. FIG. 図５は、実施の形態１に係るバスバー電極の構成の一例を示す平面図である。FIG. 5 is a plan view showing an example of the configuration of the bus bar electrode according to the first embodiment. 図６は、実施の形態１に係るバスバー電極の構成の一例を示す平面図である。FIG. 6 is a plan view showing an example of the configuration of the bus bar electrode according to the first embodiment. 図７は、実施の形態１に係るバスバー電極の構成の一例を示す平面図である。FIG. 7 is a plan view showing an example of the configuration of the bus bar electrode according to the first embodiment. 図８は、実施の形態２に係るバスバー電極の構成の一例を示す平面図である。FIG. 8 is a plan view showing an example of the configuration of the bus bar electrode according to the second embodiment. 図９は、実施の形態２に係るバスバー電極の構成の一例を示す平面図である。FIG. 9 is a plan view showing an example of the configuration of the bus bar electrode according to the second embodiment. 図１０は、実施の形態２に係るバスバー電極の構成の一例を示す平面図である。FIG. 10 is a plan view showing an example of the configuration of the bus bar electrode according to the second embodiment. 図１１は、実施の形態３に係るバスバー電極の構成の一例を示す平面図である。FIG. 11 is a plan view showing an example of the configuration of the bus bar electrode according to the third embodiment. 図１２は、実施の形態３に係るバスバー電極の構成の一例を示す平面図である。FIG. 12 is a plan view showing an example of the configuration of the bus bar electrode according to the third embodiment. 図１３は、実施の形態３の変形例に係るバスバー電極の構成の一例を示す平面図である。FIG. 13 is a plan view showing an example of the configuration of a bus bar electrode according to a modification of the third embodiment. 図１４は、実施の形態３の変形例に係るバスバー電極の構成の一例を示す平面図である。FIG. 14 is a plan view showing an example of a configuration of a bus bar electrode according to a modification of the third embodiment. 図１５は、実施の形態３及びその変形例に係る太陽電池素子における受光電荷の流れを説明する模式図である。FIG. 15 is a schematic diagram for explaining the flow of received light charges in the solar cell element according to Embodiment 3 and its modification. 図１６は、実施の形態４に係るバスバー電極の構成の一例を示す平面図である。FIG. 16 is a plan view showing an example of the configuration of the bus bar electrode according to the fourth embodiment. 図１７は、実施の形態４に係るバスバー電極の構成の一例を示す平面図である。FIG. 17 is a plan view showing an example of the configuration of the bus bar electrode according to the fourth embodiment. 図１８は、実施の形態４に係るバスバー電極の構成の一例を示す平面図である。FIG. 18 is a plan view showing an example of the configuration of the bus bar electrode according to the fourth embodiment. 図１９は、その他の実施の形態に係るバスバー電極の構成の一例を示す平面図である。FIG. 19 is a plan view showing an example of a configuration of a bus bar electrode according to another embodiment. 図２０は、その他の実施の形態に係るバスバー電極の構成の一例を示す平面図である。FIG. 20 is a plan view showing an example of a configuration of a bus bar electrode according to another embodiment. 図２１は、その他の実施の形態に係るバスバー電極の構成の一例を示す平面図である。FIG. 21 is a plan view showing an example of a configuration of a bus bar electrode according to another embodiment.
　以下では、本発明の実施の形態に係る太陽電池モジュールについて、図面を用いて詳細に説明する。以下に説明する実施の形態は、いずれも本発明の好ましい一具体例を示すものである。したがって、以下の実施の形態で示される数値、形状、材料、構成要素、構成要素の配置及び接続形態などは、一例であり、本発明を限定する趣旨ではない。よって、以下の実施の形態における構成要素のうち、本発明の最上位概念を示す独立請求項に記載されていない構成要素については、任意の構成要素として説明される。 Hereinafter, the solar cell module according to the embodiment of the present invention will be described in detail with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.
　また、各図は、模式図であり、必ずしも厳密に図示されたものではない。また、各図において、同じ構成部材については同じ符号を付している。 Each figure is a schematic diagram and is not necessarily shown strictly. Moreover, in each figure, the same code | symbol is attached | subjected about the same structural member.
　本明細書において、太陽電池素子の「表面」とは、その反対側の面である「裏面」に比べ、例えば、光が多く内部へ入射可能な面を意味（５０％超過～１００％の光が表面から内部に入射する）、し、「裏面」側から光が内部に全く入らない場合も含む。また太陽電池モジュールの「表面」とは、太陽電池素子の「表面」と対向する側の光が入射可能な面を意味し、「裏面」とはその反対側の面を意味する。また、「第１の部材上に第２の部材を設ける」などの記載は、特に限定を付さない限り、第１及び第２の部材が直接接触して設けられる場合のみを意図しない。即ち、この記載は、第１及び第２の部材の間に他の部材が存在する場合を含む。また、「略＊＊」との記載は、「略同一」を例に挙げて説明すると、全く同一はもとより、実質的に同一と認められるものを含む意図である。 In this specification, the “front surface” of the solar cell element means, for example, a surface in which more light can enter the interior than the “back surface” that is the opposite surface (light exceeding 50% to 100% light). Is incident on the inside from the front surface), and no light enters the interior from the “back surface” side. The “surface” of the solar cell module means a surface on which light on the side facing the “surface” of the solar cell element can be incident, and the “back surface” means a surface on the opposite side. In addition, descriptions such as “providing the second member on the first member” do not intend only when the first and second members are provided in direct contact unless specifically limited. That is, this description includes a case where another member exists between the first and second members. In addition, the description of “substantially **” is intended to include not only exactly the same, but also those that are recognized as being substantially the same, with “substantially identical” as an example.
　（実施の形態１）
　実施の形態１に係る太陽電池モジュールについて、図１～７を用いて説明する。 (Embodiment 1)
The solar cell module according to Embodiment 1 will be described with reference to FIGS.
　［１－１．太陽電池モジュールの基本構成］
　本実施の形態に係る太陽電池モジュールの基本構成の一例について、図１を用いて説明する。 [1-1. Basic configuration of solar cell module]
An example of the basic configuration of the solar cell module according to this embodiment will be described with reference to FIG.
　図１は、実施の形態１に係る太陽電池モジュール１の概観平面図である。同図に示された太陽電池モジュール１は、複数の太陽電池素子１１と、タブ配線２０と、わたり配線３０と、枠体６０とを備える。 FIG. 1 is a schematic plan view of a solar cell module 1 according to Embodiment 1. FIG. The solar cell module 1 shown in the figure includes a plurality of solar cell elements 11, a tab wiring 20, a cross wiring 30, and a frame body 60.
　太陽電池素子１１は、受光面に平行な方向で２次元状に配置され、光照射により電力を発生する平板状の光起電力セルである。ここで、受光面とは、後述する受光面電極１０２の面を意味する。以下の説明では、特に限定を付さない限り、「平面視」とは、受光面に垂直な方向から見ることを意味する。 The solar cell element 11 is a planar photovoltaic cell that is two-dimensionally arranged in a direction parallel to the light receiving surface and generates electric power by light irradiation. Here, the light receiving surface means a surface of a light receiving surface electrode 102 described later. In the following description, unless otherwise specified, “plan view” means viewing from a direction perpendicular to the light receiving surface.
　タブ配線２０は、隣り合う２つの太陽電池素子１１の一方の表面及び他方の裏面に配置され、隣接する太陽電池素子１１を電気的に接続する長尺状の配線部材である。タブ配線２０は、例えば列方向に隣接する太陽電池素子１１を後述する図４に示されるように電気的に接続する。 The tab wiring 20 is a long wiring member that is disposed on one front surface and the other back surface of two adjacent solar cell elements 11 and electrically connects the adjacent solar cell elements 11. The tab wiring 20 electrically connects the solar cell elements 11 adjacent in the column direction, for example, as shown in FIG.
　わたり配線３０は、太陽電池ストリングどうしを接続する配線部材である。なお、太陽電池ストリングとは、列方向に配置されタブ配線２０により接続された複数の太陽電池素子１１の集合体である。 The cross wiring 30 is a wiring member for connecting the solar cell strings. The solar cell string is an aggregate of a plurality of solar cell elements 11 arranged in the column direction and connected by the tab wiring 20.
　枠体６０は、複数の太陽電池素子１１が２次元配列されたパネルの外周部を覆う外枠部材である。 The frame body 60 is an outer frame member that covers the outer peripheral portion of the panel in which the plurality of solar cell elements 11 are two-dimensionally arranged.
　［１－２．太陽電池素子の構造］
　太陽電池モジュール１の主たる構成要素である太陽電池素子１１の構造について説明する。 [1-2. Structure of solar cell element]
The structure of the solar cell element 11 which is the main component of the solar cell module 1 will be described.
　図２は、実施の形態１に係る太陽電池素子１１の平面図である。同図に示すように、太陽電池素子１１は、平面視において略正方形状である。太陽電池素子１１は、例えば、縦１２５ｍｍ×横１２５ｍｍ×厚み２００μｍである。また、太陽電池素子１１の表面上には、ストライプ状の複数のバスバー電極４０が互いに平行に形成され、バスバー電極４０と直交するようにストライプ状の複数のフィンガー電極５０が互いに平行に形成されている。なお、複数のバスバー電極４０のそれぞれの間隔及び複数のフィンガー電極５０のそれぞれの間隔は図２に示されるものに限定されない。 FIG. 2 is a plan view of the solar cell element 11 according to the first embodiment. As shown in the figure, the solar cell element 11 has a substantially square shape in plan view. The solar cell element 11 is, for example, 125 mm long × 125 mm wide × 200 μm thick. Further, on the surface of the solar cell element 11, a plurality of striped bus bar electrodes 40 are formed in parallel to each other, and a plurality of striped finger electrodes 50 are formed in parallel to each other so as to be orthogonal to the bus bar electrodes 40. Yes. In addition, each space | interval of the some bus-bar electrode 40 and each space | interval of the several finger electrode 50 are not limited to what is shown by FIG.
　バスバー電極４０の上には、図２において点線で示されるようにタブ配線２０が接合されている。バスバー電極４０及びタブ配線２０は、例えば略同一の線幅を有する。太陽電池素子１１で生成された受光電荷は、フィンガー電極５０で集電される。そして、フィンガー電極５０で集電された受光電荷は、バスバー電極４０へ伝達され、さらに、バスバー電極４０の直上に接合されたタブ配線２０へ伝達される。また、バスバー電極４０は、例えば図２に示されるような開口部を有する。バスバー電極４０が有する開口部の詳細については後述する。バスバー電極４０及びフィンガー電極５０は、集電極１００を構成する。集電極１００は、例えば、Ａｇ（銀）などの導電性粒子を含む導電性ペーストにより形成される。なお、図２では、バスバー電極４０及びフィンガー電極５０にハッチングを付加しているが、ここでのハッチングは、開口部と区別するために付加したものであって、断面を意味するものではない。同様に後述する図５～２１に示されるバスバー電極及びフィンガー電極に付加されたハッチングも断面を意味するものではない。 The tab wiring 20 is joined on the bus bar electrode 40 as shown by a dotted line in FIG. The bus bar electrode 40 and the tab wiring 20 have, for example, substantially the same line width. The received light charges generated by the solar cell element 11 are collected by the finger electrode 50. The light-receiving charges collected by the finger electrodes 50 are transmitted to the bus bar electrode 40 and further transmitted to the tab wiring 20 joined immediately above the bus bar electrode 40. The bus bar electrode 40 has an opening as shown in FIG. Details of the opening of the bus bar electrode 40 will be described later. The bus bar electrode 40 and the finger electrode 50 constitute a collector electrode 100. The collector electrode 100 is formed of, for example, a conductive paste containing conductive particles such as Ag (silver). In FIG. 2, hatching is added to the bus bar electrode 40 and the finger electrode 50, but the hatching here is added to distinguish from the opening and does not mean a cross section. Similarly, hatching added to bus bar electrodes and finger electrodes shown in FIGS. 5 to 21 described later does not mean a cross section.
　図３は、実施の形態１に係る太陽電池素子１１の積層構造を表す断面図である。なお、同図は、図２における太陽電池素子１１のＩＩＩ－ＩＩＩ断面図である。図３に示されるように、ｎ型単結晶シリコンウエハ１０１の主面上にｉ型非晶質シリコン膜１２１及びｐ型非晶質シリコン膜１２２が、この順で形成されている。ｎ型単結晶シリコンウエハ１０１、ｉ型非晶質シリコン膜１２１及びｐ型非晶質シリコン膜１２２は、光電変換層を形成し、ｎ型単結晶シリコンウエハ１０１が主たる発電層となる。さらに、ｐ型非晶質シリコン膜１２２上に、受光面電極１０２が形成されている。図３に示されるように、受光面電極１０２上には、複数のバスバー電極４０及び複数のフィンガー電極５０からなる集電極１００が形成されている。なお、図３では、集電極１００のうち、フィンガー電極５０のみが示されている。 FIG. 3 is a cross-sectional view showing the laminated structure of solar cell element 11 according to Embodiment 1. 2 is a cross-sectional view taken along the line III-III of the solar cell element 11 in FIG. As shown in FIG. 3, an i-type amorphous silicon film 121 and a p-type amorphous silicon film 122 are formed in this order on the main surface of an n-type single crystal silicon wafer 101. The n-type single crystal silicon wafer 101, the i-type amorphous silicon film 121, and the p-type amorphous silicon film 122 form a photoelectric conversion layer, and the n-type single crystal silicon wafer 101 serves as a main power generation layer. Further, the light receiving surface electrode 102 is formed on the p-type amorphous silicon film 122. As shown in FIG. 3, a collecting electrode 100 including a plurality of bus bar electrodes 40 and a plurality of finger electrodes 50 is formed on the light receiving surface electrode 102. In FIG. 3, only the finger electrode 50 of the collector electrode 100 is shown.
　また、ｎ型単結晶シリコンウエハ１０１の裏面には、ｉ型非晶質シリコン膜１２３及びｎ型非晶質シリコン膜１２４が、この順で形成されている。さらに、ｎ型非晶質シリコン膜１２４上に、受光面電極１０３が形成され、受光面電極１０３上に、複数のバスバー電極４０及び複数のフィンガー電極５０からなる集電極１００が形成されている。 Further, an i-type amorphous silicon film 123 and an n-type amorphous silicon film 124 are formed in this order on the back surface of the n-type single crystal silicon wafer 101. Further, the light receiving surface electrode 103 is formed on the n-type amorphous silicon film 124, and the collector electrode 100 including the plurality of bus bar electrodes 40 and the plurality of finger electrodes 50 is formed on the light receiving surface electrode 103.
　なお、ｐ型非晶質シリコン膜１２２がｎ型単結晶シリコンウエハ１０１の裏面側に、ｎ型非晶質シリコン膜１２４がｎ型単結晶シリコンウエハ１０１の受光面側にそれぞれ形成されていてもよい。 Even if the p-type amorphous silicon film 122 is formed on the back surface side of the n-type single crystal silicon wafer 101 and the n-type amorphous silicon film 124 is formed on the light-receiving surface side of the n-type single crystal silicon wafer 101, respectively. Good.
　集電極１００は、例えば、樹脂材料をバインダとし、銀粒子などの導電性粒子をフィラーとした熱硬化型である樹脂型導電性ペーストを用いて、スクリーン印刷などの印刷法により形成することができる。 The collector electrode 100 can be formed by a printing method such as screen printing using, for example, a thermosetting resin-type conductive paste using a resin material as a binder and conductive particles such as silver particles as a filler. .
　なお、図３に示されるように、裏面のフィンガー電極５０のピッチは、表面のフィンガー電極５０のピッチと同じであるが、裏面のフィンガー電極５０のピッチが表面のフィンガー電極５０のピッチよりも小さくてもよい。言い換えると、裏面のフィンガー電極５０の本数は、表面のフィンガー電極５０の本数よりも多くてもよい。つまり、裏面に形成された集電極１００の面積占有率は、表面に形成された集電極の面積占有率よりも高くてもよい。ここで、集電極の面積占有率とは、平面視における太陽電池素子１１の面積に対する、平面視におけるバスバー電極４０及びフィンガー電極５０のトータル面積の割合である。 As shown in FIG. 3, the pitch of the finger electrodes 50 on the back surface is the same as the pitch of the finger electrodes 50 on the front surface, but the pitch of the finger electrodes 50 on the back surface is smaller than the pitch of the finger electrodes 50 on the front surface. May be. In other words, the number of finger electrodes 50 on the back surface may be larger than the number of finger electrodes 50 on the front surface. That is, the area occupation ratio of the collector electrode 100 formed on the back surface may be higher than the area occupation ratio of the collector electrode formed on the front surface. Here, the area occupation ratio of the collector electrode is a ratio of the total area of the bus bar electrode 40 and the finger electrode 50 in the plan view to the area of the solar cell element 11 in the plan view.
　裏面におけるフィンガー電極５０の本数が多い場合、裏面における集電効率は増加するが、表面に比べて遮光ロスが増加する。しかしながら、本実施の形態に係る太陽電池素子１１は受光面が表面である片面受光型であるので、裏面における遮光ロスの増加が与える影響よりも、裏面における集電効率の増加が与える影響のほうが大きい。よって、太陽電池素子１１の集電効率を向上させることが可能となる。 When the number of finger electrodes 50 on the back surface is large, the current collection efficiency on the back surface increases, but the light shielding loss increases compared to the front surface. However, since the solar cell element 11 according to the present embodiment is a single-sided light receiving type in which the light receiving surface is the front surface, the effect of increasing the current collection efficiency on the back surface is more than the effect of increasing the light shielding loss on the back surface. large. Therefore, the current collection efficiency of the solar cell element 11 can be improved.
　本実施の形態に係る太陽電池素子１１は、ｐｎ接合特性を改善するために、ｎ型単結晶シリコンウエハ１０１とｐ型非晶質シリコン膜１２２又はｎ型非晶質シリコン膜１２４との間に、ｉ型非晶質シリコン膜１２１を設けた構造を有している。 The solar cell element 11 according to the present embodiment is provided between the n-type single crystal silicon wafer 101 and the p-type amorphous silicon film 122 or the n-type amorphous silicon film 124 in order to improve the pn junction characteristics. The i-type amorphous silicon film 121 is provided.
　本実施の形態に係る太陽電池素子１１は、片面受光型であり、ｎ型単結晶シリコンウエハ１０１の表面側の受光面電極１０２が受光面となる。ｎ型単結晶シリコンウエハ１０１において発生したキャリアは、光電流として表面側及び裏面側の受光面電極１０２及び１０３に拡散し、集電極１００で収集される。 The solar cell element 11 according to the present embodiment is a single-sided light receiving type, and the light receiving surface electrode 102 on the surface side of the n-type single crystal silicon wafer 101 serves as a light receiving surface. Carriers generated in the n-type single crystal silicon wafer 101 diffuse as photocurrents to the light-receiving surface electrodes 102 and 103 on the front surface side and the back surface side and are collected by the collector electrode 100.
　受光面電極１０２及び１０３は、例えば、ＩＴＯ（インジウム錫酸化物）、ＳｎＯ２（酸化錫）、ＺｎＯ（酸化亜鉛）などからなる透明電極である。なお、裏面側の受光面電極１０３は、透明でない金属電極であってもよい。 The light receiving surface electrodes 102 and 103 are transparent electrodes made of, for example, ITO (indium tin oxide), SnO 2 (tin oxide), ZnO (zinc oxide), or the like. The light receiving surface electrode 103 on the back side may be a metal electrode that is not transparent.
　なお、本実施の形態に係る太陽電池素子１１は、両面受光型であってもよい。この場合には、ｎ型単結晶シリコンウエハ１０１の表面側の受光面電極１０２及び裏面側の受光面電極１０３がそれぞれ受光面となる。ｎ型単結晶シリコンウエハ１０１において発生したキャリアは、光電流として表面側及び裏面側の受光面電極１０２及び１０３に拡散し、集電極１００で収集される。また、受光面電極１０２及び１０３は、透明電極である。 The solar cell element 11 according to the present embodiment may be a double-sided light receiving type. In this case, the light receiving surface electrode 102 on the front surface side and the light receiving surface electrode 103 on the back surface side of the n-type single crystal silicon wafer 101 are light receiving surfaces. Carriers generated in the n-type single crystal silicon wafer 101 diffuse as photocurrents to the light-receiving surface electrodes 102 and 103 on the front surface side and the back surface side and are collected by the collector electrode 100. The light receiving surface electrodes 102 and 103 are transparent electrodes.
　また、太陽電池素子１１は、光起電力としての機能を有するものであればよく、太陽電池素子１１の構造は上述した構造に限定されない。 Further, the solar cell element 11 only needs to have a function as a photovoltaic power, and the structure of the solar cell element 11 is not limited to the above-described structure.
　［１－３．太陽電池モジュールの構造］
　次に、本実施の形態に係る太陽電池モジュール１の具体的構造について説明する。 [1-3. Structure of solar cell module]
Next, a specific structure of the solar cell module 1 according to the present embodiment will be described.
　図４は、実施の形態１に係る太陽電池モジュール１の列方向における構造断面図である。図４は、図１の太陽電池モジュール１におけるＩＶ－ＩＶ断面図である。同図に示された太陽電池モジュール１は、太陽電池素子１１と、タブ配線２０と、表面充填部材７０Ａ及び裏面充填部材７０Ｂと、表面保護部材８０及び裏面保護部材９０とを備える。 FIG. 4 is a structural cross-sectional view of the solar cell module 1 according to Embodiment 1 in the column direction. 4 is a cross-sectional view taken along the line IV-IV in the solar cell module 1 of FIG. The solar cell module 1 shown in the figure includes a solar cell element 11, a tab wiring 20, a surface filling member 70A and a back surface filling member 70B, a surface protection member 80, and a back surface protection member 90.
　タブ配線２０は、長尺状の導電性配線であって、例えば、リボン状の金属箔である。タブ配線２０は、例えば、銅箔や銀箔等の金属箔の表面全体を半田や銀等で被覆したものを所定の長さに短冊状に切断することによって作製することができる。列方向に隣接する２つの太陽電池素子１１において、一方の太陽電池素子１１の表面に配置されたタブ配線２０は、他方の太陽電池素子１１の裏面にも配置される。より具体的には、タブ配線２０の一端部の下面は、一方の太陽電池素子１１の表面側のバスバー電極４０（図４では図示せず）に接合される。また、タブ配線２０の他端部の上面は、他方の太陽電池素子１１の裏面側のバスバー電極４０（図４では図示せず）に接合される。これにより、列方向に配置された複数の太陽電池素子１１からなる太陽電池ストリングは、当該複数の太陽電池素子１１が列方向に直列接続された構成となっている。タブ配線２０とバスバー電極４０とは、例えば、ハンダ材により接合される。 The tab wiring 20 is a long conductive wiring, for example, a ribbon-shaped metal foil. The tab wiring 20 can be produced, for example, by cutting a metal foil such as a copper foil or a silver foil, which is covered with solder, silver, or the like into a strip having a predetermined length. In the two solar cell elements 11 adjacent to each other in the column direction, the tab wiring 20 disposed on the surface of one solar cell element 11 is also disposed on the back surface of the other solar cell element 11. More specifically, the lower surface of one end of the tab wiring 20 is joined to the bus bar electrode 40 (not shown in FIG. 4) on the surface side of one solar cell element 11. Further, the upper surface of the other end portion of the tab wiring 20 is joined to a bus bar electrode 40 (not shown in FIG. 4) on the back surface side of the other solar cell element 11. Thereby, the solar cell string composed of a plurality of solar cell elements 11 arranged in the column direction has a configuration in which the plurality of solar cell elements 11 are connected in series in the column direction. The tab wiring 20 and the bus bar electrode 40 are joined by, for example, a solder material.
　また、図４に示されるように、複数の太陽電池素子１１の表面側には表面保護部材８０が配設され、裏面側には裏面保護部材９０が配設されている。そして、複数の太陽電池素子１１を含む面と表面保護部材８０との間には表面充填部材７０Ａが配置され、複数の太陽電池素子１１を含む面と裏面保護部材９０との間には裏面充填部材７０Ｂが配置されている。表面保護部材８０及び裏面保護部材９０は、それぞれ、表面充填部材７０Ａ及び裏面充填部材７０Ｂにより固定されている。 Further, as shown in FIG. 4, a surface protection member 80 is disposed on the surface side of the plurality of solar cell elements 11, and a back surface protection member 90 is disposed on the back surface side. A surface filling member 70 </ b> A is disposed between the surface including the plurality of solar cell elements 11 and the surface protection member 80, and the back surface filling is performed between the surface including the plurality of solar cell elements 11 and the back surface protection member 90. A member 70B is arranged. The front surface protection member 80 and the back surface protection member 90 are fixed by a front surface filling member 70A and a back surface filling member 70B, respectively.
　表面保護部材８０は、太陽電池素子１１の表面側に配置された保護部材である。表面保護部材８０は、太陽電池モジュール１の内部を風雨や外部衝撃、火災などから保護し、太陽電池モジュール１の屋外暴露における長期信頼性を確保するための部材である。この観点から表面保護部材８０は、例えば、透光性及び遮水性を有するガラス、フィルム状又は板状の硬質の透光性及び遮水性を有する樹脂部材などを用いることができる。 The surface protection member 80 is a protection member disposed on the surface side of the solar cell element 11. The surface protection member 80 is a member that protects the inside of the solar cell module 1 from wind and rain, external impact, fire, and the like, and ensures long-term reliability of the solar cell module 1 when exposed outdoors. From this point of view, the surface protection member 80 can be made of, for example, glass having translucency and water shielding properties, a resin member having a light-transmitting property and water shielding properties such as a film or plate.
　裏面保護部材９０は、太陽電池素子１１の裏面側に配置された保護部材である。裏面保護部材９０は、太陽電池モジュール１の裏面を外部環境から保護する部材であり、例えば、ポリエチレンテレフタレートなどの樹脂フィルム、又は、Ａｌ箔を樹脂フィルムでサンドイッチした構造を有する積層フィルムなどを用いることができる。 The back surface protection member 90 is a protection member disposed on the back surface side of the solar cell element 11. The back surface protection member 90 is a member that protects the back surface of the solar cell module 1 from the external environment. For example, a resin film such as polyethylene terephthalate or a laminated film having a structure in which an Al foil is sandwiched between resin films is used. Can do.
　表面充填部材７０Ａは、複数の太陽電池素子１１と表面保護部材８０との間の空間に充填された充填材であり、裏面充填部材７０Ｂは、複数の太陽電池素子１１と裏面保護部材９０との間の空間に充填された充填材である。表面充填部材７０Ａ及び裏面充填部材７０Ｂは、太陽電池素子１１を外部環境から遮断するための封止機能を有している。表面充填部材７０Ａ及び裏面充填部材７０Ｂの配置により、屋外設置が想定される太陽電池モジュール１の高耐熱性及び高耐湿性を確保することが可能となる。 The front surface filling member 70 </ b> A is a filler filled in the space between the plurality of solar cell elements 11 and the surface protection member 80, and the back surface filling member 70 </ b> B is formed between the plurality of solar cell elements 11 and the back surface protection member 90. It is a filler filled in the space between. The front surface filling member 70A and the back surface filling member 70B have a sealing function for blocking the solar cell element 11 from the external environment. With the arrangement of the front surface filling member 70A and the back surface filling member 70B, it is possible to ensure high heat resistance and high moisture resistance of the solar cell module 1 assumed to be installed outdoors.
　表面充填部材７０Ａは、封止機能を有する透光性の高分子材料からなる。表面充填部材７０Ａの高分子材料は、例えば、エチレンビニルアセテート（ＥＶＡ）等の透光性樹脂材料が挙げられる。 The surface filling member 70A is made of a translucent polymer material having a sealing function. Examples of the polymer material of the surface filling member 70A include translucent resin materials such as ethylene vinyl acetate (EVA).
　裏面充填部材７０Ｂは、封止機能を有する高分子材料からなる。ここで、裏面充填部材７０Ｂは、白色加工されている。裏面充填部材７０Ｂの高分子材料は、例えば、ＥＶＡ等が白色加工された樹脂材料が挙げられる。 The back surface filling member 70B is made of a polymer material having a sealing function. Here, the back surface filling member 70B is processed in white. Examples of the polymer material of the back surface filling member 70B include a resin material obtained by processing EVA or the like in white.
　なお、製造工程の簡素化及び表面充填部材７０Ａと裏面充填部材７０Ｂとの界面の密着性といった観点から、表面充填部材７０Ａと裏面充填部材７０Ｂとは、同じ材料系であることが好ましい。表面充填部材７０Ａ及び裏面充填部材７０Ｂは、複数の太陽電池素子１１（セルストリング）を挟んだ２つの樹脂シート（透光性のＥＶＡシートと白色加工されたＥＶＡシート）をラミネート処理（ラミネート加工）することで形成される。 In addition, it is preferable that the surface filling member 70A and the back surface filling member 70B are made of the same material system from the viewpoint of simplification of the manufacturing process and the adhesion of the interface between the surface filling member 70A and the back surface filling member 70B. The front surface filling member 70A and the back surface filling member 70B are obtained by laminating (laminating) two resin sheets (translucent EVA sheet and white processed EVA sheet) sandwiching a plurality of solar cell elements 11 (cell strings). It is formed by doing.
　［１－４．実施の形態１に係るバスバー電極の構成］
　図５～７は、実施の形態１に係るバスバー電極４０の構成の一例を示す平面図である。 [1-4. Configuration of Bus Bar Electrode According to Embodiment 1]
5 to 7 are plan views showing an example of the configuration of the bus bar electrode 40 according to the first embodiment.
　図５～７には、バスバー電極４０の他にフィンガー電極５０が図示されている。なお、太陽電池素子１１の表面及び裏面のうちの少なくとも一方におけるバスバー電極が、図５～７に示されるバスバー電極４０の構成を有する。つまり、図５～７に示されるバスバー電極４０の構成を太陽電池素子１１の表面のみ、裏面のみ、又は、両面のバスバー電極が有してもよい。なお、後述する図８～１４、図１６～２１についても同様である。 5 to 7 show a finger electrode 50 in addition to the bus bar electrode 40. The bus bar electrode on at least one of the front and back surfaces of the solar cell element 11 has the configuration of the bus bar electrode 40 shown in FIGS. That is, the bus bar electrode 40 shown in FIGS. 5 to 7 may have only the front surface, the back surface, or both surfaces of the solar cell element 11. The same applies to FIGS. 8 to 14 and FIGS. 16 to 21 described later.
　バスバー電極４０は、タブ配線２０の長尺方向に沿って形成され、タブ配線２０と重なって接合する長尺状の電極である。バスバー電極４０は、太陽電池素子１１で生成された受光電荷をタブ配線２０に伝達する電荷伝達部４１を有する。また、バスバー電極４０は、複数の開口部４２を有する。複数の開口部４２は、タブ配線２０の長尺方向（バスバー電極４０の長手方向）に沿って並んで設けられる。なお、以下では、タブ配線２０の長尺方向を、単に、長尺方向とも呼ぶ。 The bus bar electrode 40 is a long electrode that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap. The bus bar electrode 40 has a charge transfer portion 41 that transfers the light-receiving charge generated by the solar cell element 11 to the tab wiring 20. The bus bar electrode 40 has a plurality of openings 42. The plurality of openings 42 are provided side by side along the longitudinal direction of the tab wiring 20 (longitudinal direction of the bus bar electrode 40). Hereinafter, the longitudinal direction of the tab wiring 20 is also simply referred to as a longitudinal direction.
　また、複数の開口部４２には、平面視における面積が異なる開口部４２が含まれる。具体的には、複数の開口部４２のうちの面積の異なる開口部４２の長尺方向の幅及び長尺方向と平面視において交差する交差方向（バスバー電極４０の短手方向）の幅の少なくとも一方が異なる。当該交差方向は、例えば、長尺方向と平面視において略垂直な方向である。なお、複数の開口部４２全ての平面視における面積が異なってもよい。また、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の中央及び両端のうちのどちらか一方に近いほど大きくてもよい。 The plurality of openings 42 include openings 42 having different areas in plan view. Specifically, at least the width in the long direction of the openings 42 having different areas among the plurality of openings 42 and the width in the crossing direction (the short direction of the bus bar electrode 40) intersecting the long direction in plan view. One is different. The crossing direction is, for example, a direction substantially perpendicular to the long direction in plan view. In addition, the area in planar view of all the plurality of openings 42 may be different. In addition, the area of the plurality of openings 42 in plan view may be larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction.
　図５では、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の両端に近いほど大きい。例えば、複数の開口部４２の、交差方向の幅は同じであり、長尺方向の幅が異なる。具体的には、複数の開口部４２の長尺方向の幅が、長尺方向におけるバスバー電極４０の両端に近いほど大きい。これにより、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の両端に近いほど大きくなる。 In FIG. 5, the area of the plurality of openings 42 in plan view is larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction. For example, the plurality of openings 42 have the same width in the intersecting direction and different widths in the longitudinal direction. Specifically, the width in the longitudinal direction of the plurality of openings 42 is larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction. Thereby, the area in the planar view of the plurality of openings 42 becomes larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction.
　また、図６では、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の中央に近いほど大きい。例えば、複数の開口部４２の交差方向の幅は同じであり、長尺方向の幅が異なる。具体的には、複数の開口部４２の長尺方向の幅が、長尺方向におけるバスバー電極４０の中央に近いほど大きい。これにより、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の中央に近いほど大きくなる。 In FIG. 6, the area of the plurality of openings 42 in plan view is larger as it is closer to the center of the bus bar electrode 40 in the longitudinal direction. For example, the widths in the intersecting direction of the plurality of openings 42 are the same, and the widths in the longitudinal direction are different. Specifically, the width in the longitudinal direction of the plurality of openings 42 increases as the distance from the center of the bus bar electrode 40 in the longitudinal direction increases. As a result, the area of the plurality of openings 42 in plan view increases as the area is closer to the center of the bus bar electrode 40 in the longitudinal direction.
　また、図７では、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の両端に近いほど大きい。例えば、複数の開口部４２の交差方向の幅及び長尺方向の幅の少なくとも一方が異なる。具体的には、長尺方向におけるバスバー電極４０の両端に近い位置にある開口部４２の長尺方向及び交差方向の幅が、その他の開口部４２の長尺方向及び交差方向の幅よりも大きい。また、その他の開口部４２の交差方向の幅は、長尺方向におけるバスバー電極４０の中央に近いほど小さい。これにより、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の両端に近いほど大きくなる。 In FIG. 7, the area of the plurality of openings 42 in plan view is larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction. For example, at least one of the width in the intersecting direction and the width in the longitudinal direction of the plurality of openings 42 is different. Specifically, the width in the longitudinal direction and the intersecting direction of the opening 42 located near both ends of the bus bar electrode 40 in the longitudinal direction is larger than the width in the longitudinal direction and the intersecting direction of the other opening 42. . Further, the width of the other opening portions 42 in the intersecting direction is smaller as it is closer to the center of the bus bar electrode 40 in the longitudinal direction. Thereby, the area in the planar view of the plurality of openings 42 becomes larger as it is closer to both ends of the bus bar electrode 40 in the longitudinal direction.
　このように、バスバー電極４０は、長尺方向に沿って並んで設けられ、平面視における面積が長尺方向に沿って不均一な複数の開口部４２を有する。これにより、バスバー電極４０は、例えば、図５～７に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部４１の面積占有率が異なる領域を有する。例えば、第１の領域における電荷伝達部４１の面積占有率は、第２の領域における電荷伝達部４１の面積占有率よりも大きい。ただし、第１の領域及び第２の領域の大きさは、それぞれ同じ大きさを有する。また、第１の領域及び第２の領域の大きさは、所定の大きさ以上である必要がある。例えば、所定の大きさは、少なくとも１つの開口部４２を含む大きさである。 Thus, the bus bar electrodes 40 are provided side by side along the longitudinal direction, and have a plurality of openings 42 whose area in plan view is non-uniform along the longitudinal direction. As a result, the bus bar electrode 40 has regions with different area occupancy rates of the charge transfer portions 41 for the respective regions, such as the first region and the second region shown in FIGS. For example, the area occupancy of the charge transfer unit 41 in the first region is larger than the area occupancy of the charge transfer unit 41 in the second region. However, the first region and the second region have the same size. Further, the size of the first region and the second region needs to be equal to or larger than a predetermined size. For example, the predetermined size is a size including at least one opening 42.
　また、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の中央及び両端のうちのどちらか一方に近いほど大きい。これにより、バスバー電極４０は、例えば、図５及び図７に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極４０の中央側の領域ほど、長尺方向におけるバスバー電極４０の両端側の領域よりもそれぞれの領域に対する電荷伝達部４１の面積占有率が大きくなる領域を有する。または、バスバー電極４０は、例えば、図６に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極４０の両端側の領域ほど、長尺方向におけるバスバー電極４０の中央側の領域よりもそれぞれの領域に対する電荷伝達部４１の面積占有率が大きくなる領域を有する。 Further, the area of the plurality of openings 42 in plan view is larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction. Thereby, the bus bar electrode 40 is, for example, the bus bar electrode in the longitudinal direction as the central region of the bus bar electrode 40 in the longitudinal direction as in the first region and the second region shown in FIGS. 5 and 7. It has a region where the area occupancy of the charge transfer portion 41 with respect to each region is larger than the regions on both ends of the electrode 40. Alternatively, the bus bar electrode 40 is, for example, as the first region and the second region shown in FIG. 6, the regions on both ends of the bus bar electrode 40 in the longitudinal direction are closer to the center of the bus bar electrode 40 in the longitudinal direction. There are regions in which the area occupancy of the charge transfer portion 41 with respect to each region is larger than the region on the side.
　なお、第１の領域及び第２の領域は、図５～７に示される領域に限らず、図５～７に示される領域とは異なる位置の領域であってもよい。 Note that the first region and the second region are not limited to the regions shown in FIGS. 5 to 7, and may be regions at positions different from the regions shown in FIGS.
　［１－５．効果等］
　従来の太陽電池モジュールでは、バスバー電極とタブ配線とが接続されていない部分が一様に存在することから、セル割れなどの不具合が発生していない状態であっても、バスバー電極とタブ配線とが接続されていない部分の電気的ロスによってモジュール出力が低下する。したがって、セル割れなどの不具合は常に発生する訳ではないので、不具合が発生していない場合にはタブ配線とバスバー電極とが接続する部分を増やすことで電気的ロスを低減し、万が一ストレスなどでセル割れなどの不具合が発生するような状況になった場合に、ストレスを緩和する構造に変化させることができた方が良い。 [1-5. Effect]
In the conventional solar cell module, since the portion where the bus bar electrode and the tab wiring are not connected exists uniformly, the bus bar electrode and the tab wiring The module output decreases due to the electrical loss of the part where is not connected. Therefore, defects such as cell cracks do not always occur, so if there are no defects, increase the portion where the tab wiring and bus bar electrode are connected to reduce the electrical loss. It is better to be able to change the structure to relieve stress when a situation such as a cell crack occurs.
　そこで、本実施の形態に係る太陽電池モジュール１は、隣り合う２つの太陽電池素子１１と、２つの太陽電池素子１１を電気的に接続する長尺状のタブ配線２０とを備える。２つの太陽電池素子１１のそれぞれは、タブ配線２０の長尺方向に沿って形成され、タブ配線２０と重なって接合する長尺状のバスバー電極４０を有する。バスバー電極４０は、太陽電池素子１１で生成された受光電荷をタブ配線２０に伝達する電荷伝達部４１と、複数の開口部４２とを有する。複数の開口部４２は、長尺方向に沿って並んで設けられ、複数の開口部４２には、平面視における面積が異なる開口部４２が含まれる。 Therefore, the solar cell module 1 according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11. Each of the two solar cell elements 11 has a long bus bar electrode 40 that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap. The bus bar electrode 40 has a charge transfer portion 41 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a plurality of openings 42. The plurality of openings 42 are provided side by side along the longitudinal direction, and the plurality of openings 42 include openings 42 having different areas in plan view.
　これにより、バスバー電極４０は、例えば、図５～７に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部４１の面積占有率が異なる領域を有する。つまり、電荷伝達部４１の面積占有率は、長尺方向に沿って不均一になる。言い換えると、バスバー電極４０は、タブ配線２０と電荷伝達部４１との接着強度が低い領域（第２の領域）と高い領域（第１の領域）とを有する。従来の太陽電池モジュールでは、タブ配線とバスバー電極とが接続しない部分が一様に設けられており、電気的ロスが一様に発生していた。一方、実施の形態１に係る太陽電池モジュール１では、タブ配線２０とバスバー電極４０とが接続しない部分が不均一に設けられるため、電気的ロスを小さくしている。つまり、実施の形態１に係る太陽電池モジュール１では、タブ配線２０とバスバー電極４０とが接続しない部分を場所によって小さくしているため、電気的ロスを小さくしている。したがって、温度サイクル等によりセル割れなどの不具合が発生するような状況になるまでは電気的ロスは抑制され、太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部４１との接着強度が低い領域のタブ配線２０が剥がれる。これにより、タブ配線２０のバスバー電極４０との接合が剥がれた領域にストレスを吸収させることができるため、以降は、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。また、タブ配線２０と電荷伝達部４１との接着強度が高い領域では、タブ配線２０と電荷伝達部４１とが接合しているため、集電効率の低下を抑制することができる。つまり、商品寿命内でのトータルの出力を高めた上で、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Thereby, the bus bar electrode 40 has regions having different area occupancy rates of the charge transfer portions 41 with respect to the respective regions, for example, the first region and the second region shown in FIGS. That is, the area occupancy rate of the charge transfer portion 41 becomes non-uniform along the longitudinal direction. In other words, the bus bar electrode 40 has a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 41 is low (second region) and a region where the adhesive strength is high (first region). In the conventional solar cell module, the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly. On the other hand, in the solar cell module 1 according to Embodiment 1, since the portion where the tab wiring 20 and the bus bar electrode 40 are not connected is provided unevenly, the electrical loss is reduced. That is, in the solar cell module 1 according to Embodiment 1, since the portion where the tab wiring 20 and the bus bar electrode 40 are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 41 is low is peeled off. Thereby, since stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 40 is peeled off, the stress of the solar cell element 11 and the tab wiring 20 can be reduced thereafter. Further, in the region where the adhesive strength between the tab wiring 20 and the charge transfer portion 41 is high, since the tab wiring 20 and the charge transfer portion 41 are joined, it is possible to suppress a decrease in current collection efficiency. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
　また、バスバー電極４０は、開口部４２においてタブ配線２０と接合していない。したがって、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０のバスバー電極４０と接合していない領域にストレスを吸収させることができるので、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Further, the bus bar electrode 40 is not joined to the tab wiring 20 at the opening 42. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region that is not joined to the bus bar electrode 40 of the tab wiring 20. The stress on the tab wiring 20 can be reduced.
　また、複数の開口部４２のうちの面積の異なる開口部４２の長尺方向の幅及び長尺方向と平面視において交差する交差方向の幅の少なくとも一方は、異なる。 Further, at least one of the width in the longitudinal direction of the opening 42 having a different area among the plurality of openings 42 and the width in the intersecting direction intersecting the longitudinal direction in plan view are different.
　これにより、複数の開口部４２の長尺方向の幅及び交差方向の幅の少なくとも一方を変えることで、複数の開口部４２の平面視における面積を変えることができる。 Thus, by changing at least one of the width in the longitudinal direction and the width in the intersecting direction of the plurality of openings 42, the area of the plurality of openings 42 in plan view can be changed.
　また、複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の中央及び両端のうちのどちらか一方に近いほど大きい。 Further, the area of the plurality of openings 42 in plan view is larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction.
　これにより、長尺方向におけるバスバー電極４０の中央及び両端のうちのどちらか一方側をタブ配線２０とバスバー電極４０との接着強度が低い領域にすることができる。 Thereby, one of the center and both ends of the bus bar electrode 40 in the longitudinal direction can be set to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 40 is low.
　例えば、長尺方向におけるバスバー電極４０の中央側をタブ配線２０とバスバー電極４０との接着強度が低い領域にすることで、中央側でタブ配線２０を剥がれやすくすることができる。したがって、太陽電池素子１１とタブ配線２０との接合強度が高いと、温度サイクル等によるストレスの逃げ場がないので、太陽電池素子１１に対するストレスが高まるが、中央側でタブ配線２０が剥がれることで、太陽電池素子１１に対するストレスが緩和される。 For example, by setting the central side of the bus bar electrode 40 in the longitudinal direction to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 40 is low, the tab wiring 20 can be easily peeled off at the central side. Therefore, if the bonding strength between the solar cell element 11 and the tab wiring 20 is high, there is no escape from stress due to temperature cycles or the like, so the stress on the solar cell element 11 is increased, but the tab wiring 20 is peeled off at the center side. The stress on the solar cell element 11 is alleviated.
　また、例えば、長尺方向におけるバスバー電極４０の両端側をタブ配線２０とバスバー電極４０との接着強度が低い領域にすることで、両端側でタブ配線２０が剥がれやすくすることができる。したがって、タブ配線２０の両端での自由度が高まるので、タブ配線２０の両端でのストレスを低減できる。 In addition, for example, by setting both end sides of the bus bar electrode 40 in the longitudinal direction to regions where the adhesive strength between the tab wiring 20 and the bus bar electrode 40 is low, the tab wiring 20 can be easily peeled off at both end sides. Therefore, the degree of freedom at both ends of the tab wiring 20 is increased, so that stress at both ends of the tab wiring 20 can be reduced.
　なお、図５～７に示される複数の開口部４２の平面視における面積は、長尺方向におけるバスバー電極４０の中央及び両端のうちのどちらか一方に近いほど大きかったが、これに限らない。例えば、複数の開口部４２の平面視における面積は、異なる面積であればよく、長尺方向におけるバスバー電極４０の中央及び両端のうちのどちらか一方から他方に向けて順番に大きくならなくてもよい。つまり、バスバー電極４０の中央及び両端のうちのどちらか一方の領域ではなく、バスバー電極４０の任意の領域をタブ配線２０とバスバー電極４０との接着強度が低い領域にしてもよい。これにより、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部４１との接着強度が低い領域のタブ配線２０が剥がれる。したがって、タブ配線２０のバスバー電極４０との接合が剥がれた領域にストレスを吸収させることができるため、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Although the area in plan view of the plurality of openings 42 shown in FIGS. 5 to 7 is larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction, it is not limited thereto. For example, the areas of the plurality of openings 42 in plan view may be different areas, and may not increase in order from one of the center and both ends of the bus bar electrode 40 in the longitudinal direction toward the other. Good. That is, any region of the bus bar electrode 40 may be an area where the adhesive strength between the tab wiring 20 and the bus bar electrode 40 is low, instead of one of the center and both ends of the bus bar electrode 40. Thereby, even if the solar cell element 11 and the tab wiring 20 are stressed due to a temperature cycle or the like, the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 41 is low is peeled off. Therefore, the stress can be absorbed in the region where the bonding of the tab wiring 20 with the bus bar electrode 40 is peeled off, so that the stress of the solar cell element 11 and the tab wiring 20 can be reduced.
　（実施の形態２）
　次に、実施の形態２に係る太陽電池モジュールについて、図８～１０を用いて説明する。 (Embodiment 2)
Next, a solar cell module according to Embodiment 2 will be described with reference to FIGS.
　本実施の形態に係る太陽電池モジュールは、隣り合う２つの太陽電池素子１１と、２つの太陽電池素子１１を電気的に接続する長尺状のタブ配線２０とを備える。２つの太陽電池素子１１のそれぞれは、タブ配線２０の長尺方向に沿って形成され、タブ配線２０と重なって接合する長尺状のバスバー電極１４０を有する。バスバー電極１４０は、太陽電池素子１１で生成された受光電荷をタブ配線２０に伝達する電荷伝達部１４１と、複数の開口部１４２とを有する。 The solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11. Each of the two solar cell elements 11 has a long bus bar electrode 140 that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap. The bus bar electrode 140 includes a charge transfer unit 141 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a plurality of openings 142.
　このように、本実施の形態に係る太陽電池モジュールの構造、及び、太陽電池素子１１の構造については、実施の形態１に係るそれらと同様であるため詳細な説明を省略し、以下、実施の形態１と異なるバスバー電極１４０を中心に説明する。 Thus, since the structure of the solar cell module according to the present embodiment and the structure of the solar cell element 11 are the same as those according to the first embodiment, a detailed description thereof will be omitted. The bus bar electrode 140 different from that of the first embodiment will be mainly described.
　［２－１．実施の形態２に係るバスバー電極の構成］
　図８～１０は、実施の形態２に係るバスバー電極１４０の構成の一例を示す平面図である。 [2-1. Configuration of Bus Bar Electrode According to Second Embodiment]
8 to 10 are plan views showing an example of the configuration of the bus bar electrode 140 according to the second embodiment.
　本実施の形態では、複数の開口部１４２は、長尺方向及び長尺方向と平面視において交差する交差方向に沿って並んで設けられ、複数の開口部１４２の交差方向に沿って並んで設けられる数は、長尺方向に沿って異なる。なお、複数の開口部１４２の平面視における面積は、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方に近いほど大きくてもよい。また、複数の開口部１４２が交差方向に沿って並んで設けられる数は、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方に近いほど多くてもよい。 In the present embodiment, the plurality of openings 142 are provided side by side along the longitudinal direction and the crossing direction that intersects the long direction in plan view, and are provided side by side along the crossing direction of the plurality of openings 142. The number obtained varies along the longitudinal direction. In addition, the area of the plurality of openings 142 in plan view may be larger as it is closer to either the center or both ends of the bus bar electrode 140 in the longitudinal direction. Further, the number of the plurality of openings 142 provided side by side in the crossing direction may be as large as closer to either the center or both ends of the bus bar electrode 140 in the longitudinal direction.
　図８では、複数の開口部１４２の交差方向に沿って並んで設けられる数は、長尺方向におけるバスバー電極１４０の両端に近いほど多い。例えば、長尺方向におけるバスバー電極１４０の両端では、開口部１４２は４つ設けられ、長尺方向におけるバスバー電極１４０の中央では、開口部１４２は１つ設けられる。また、長尺方向におけるバスバー電極１４０の両端の開口部１４２の平面視における面積が、その他の開口部１４２の面積よりも大きい。例えば、複数の開口部１４２のそれぞれの交差方向の幅は同じであり、長尺方向におけるバスバー電極１４０の両端の開口部１４２の長尺方向の幅が、その他の開口部１４２の長尺方向の幅よりも大きい。 In FIG. 8, the number of the plurality of openings 142 provided side by side along the intersecting direction is larger as it is closer to both ends of the bus bar electrode 140 in the longitudinal direction. For example, four openings 142 are provided at both ends of the bus bar electrode 140 in the longitudinal direction, and one opening 142 is provided at the center of the bus bar electrode 140 in the longitudinal direction. Further, the area of the opening 142 at both ends of the bus bar electrode 140 in the longitudinal direction in plan view is larger than the area of the other opening 142. For example, the widths of the plurality of openings 142 in the intersecting direction are the same, and the widths of the openings 142 at both ends of the bus bar electrode 140 in the longitudinal direction are the same as the widths of the other openings 142 in the longitudinal direction. Greater than width.
　また、図９では、複数の開口部１４２の交差方向に沿って並んで設けられる数は、長尺方向におけるバスバー電極１４０の中央に近いほど多い。例えば、長尺方向におけるバスバー電極１４０の両端では、開口部１４２は１つ設けられ、長尺方向におけるバスバー電極１４０の中央では、開口部１４２は４つ設けられる。また、長尺方向におけるバスバー電極１４０の中央の開口部１４２の平面視における面積が、その他の開口部１４２の面積よりも大きい。例えば、複数の開口部１４２のそれぞれの交差方向の幅は同じであり、長尺方向におけるバスバー電極１４０の中央の開口部１４２の長尺方向の幅が、その他の開口部１４２の長尺方向の幅よりも大きい。 In FIG. 9, the number of the plurality of openings 142 provided side by side along the intersecting direction increases as the distance from the center of the bus bar electrode 140 in the longitudinal direction increases. For example, one opening 142 is provided at both ends of the bus bar electrode 140 in the longitudinal direction, and four openings 142 are provided at the center of the bus bar electrode 140 in the longitudinal direction. In addition, the area of the opening 142 at the center of the bus bar electrode 140 in the longitudinal direction in plan view is larger than the areas of the other openings 142. For example, the widths in the intersecting direction of the plurality of openings 142 are the same, and the width in the longitudinal direction of the central opening 142 of the bus bar electrode 140 in the longitudinal direction is the same as the width in the longitudinal direction of the other openings 142. Greater than width.
　また、交差方向に沿って隣り合う２つの開口部１４２の間隔は、交差方向におけるバスバー電極１４０の中央に近いほど大きくてもよい。ここで、交差方向におけるバスバー電極１４０の中央に近い隣り合う２つの開口部１４２の間隔とは、例えば、図１０に示される電荷伝達部１４１ａの交差方向の幅である。図１０に示されるように、電荷伝達部１４１ａの交差方向の幅は、電荷伝達部１４１ａと交差方向に沿って並ぶ電荷伝達部１４１ｂの交差方向の幅よりも大きい。 Further, the interval between the two openings 142 adjacent in the cross direction may be larger as the distance from the center of the bus bar electrode 140 in the cross direction is closer. Here, the interval between two adjacent openings 142 close to the center of the bus bar electrode 140 in the intersecting direction is, for example, the width in the intersecting direction of the charge transfer portion 141a shown in FIG. As shown in FIG. 10, the width in the cross direction of the charge transfer unit 141a is larger than the width in the cross direction of the charge transfer unit 141b arranged along the cross direction with the charge transfer unit 141a.
　このように、バスバー電極１４０は、長尺方向及び交差方向に沿って並んで設けられ、交差方向に沿って並んで設けられる数が長尺方向に沿って不均一な複数の開口部１４２を有する。これにより、バスバー電極１４０は、例えば、図８～１０に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部１４１の面積占有率が異なる領域を有する。例えば、第１の領域における電荷伝達部１４１の面積占有率は、第２の領域における電荷伝達部１４１の面積占有率よりも大きい。ただし、第１の領域及び第２の領域の大きさは、それぞれ同じ大きさを有する。また、第１の領域及び第２の領域の大きさは、所定の大きさ以上である必要がある。例えば、所定の大きさは、交差方向に沿って並ぶ複数の開口部１４２及び交差方向におけるバスバー電極１４０の両端を含む大きさである。 Thus, the bus bar electrodes 140 are provided side by side along the longitudinal direction and the crossing direction, and have a plurality of openings 142 in which the number provided side by side along the crossing direction is non-uniform along the longitudinal direction. . Thereby, the bus bar electrode 140 has regions having different area occupancy rates of the charge transfer portions 141 for the respective regions, such as the first region and the second region shown in FIGS. For example, the area occupation rate of the charge transfer unit 141 in the first region is larger than the area occupation rate of the charge transfer unit 141 in the second region. However, the first region and the second region have the same size. Further, the size of the first region and the second region needs to be equal to or larger than a predetermined size. For example, the predetermined size is a size including a plurality of openings 142 arranged in the intersecting direction and both ends of the bus bar electrode 140 in the intersecting direction.
　また、複数の開口部１４２の交差方向に沿って並んで設けられる数は、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方に近いほど多い。これにより、バスバー電極１４０は、例えば、図８及び図１０に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極１４０の中央側の領域ほど、長尺方向におけるバスバー電極１４０の両端側の領域よりもそれぞれの領域に対する電荷伝達部１４１の面積占有率が大きくなる領域を有する。または、バスバー電極１４０は、例えば、図９に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極１４０の両端側の領域ほど、長尺方向におけるバスバー電極１４０の中央側の領域よりもそれぞれの領域に対する電荷伝達部１４１の面積占有率が大きくなる領域を有する。 Further, the number of the plurality of openings 142 provided side by side along the intersecting direction is larger as it is closer to either the center or both ends of the bus bar electrode 140 in the longitudinal direction. As a result, the bus bar electrode 140 has a bus bar in the longitudinal direction that is closer to the center side of the bus bar electrode 140 in the longitudinal direction, such as the first region and the second region shown in FIGS. 8 and 10. It has a region where the area occupancy of the charge transfer portion 141 with respect to each region is larger than the regions on both ends of the electrode 140. Alternatively, the bus bar electrode 140 is, for example, as the first region and the second region shown in FIG. 9, the regions on both ends of the bus bar electrode 140 in the longitudinal direction are closer to the center of the bus bar electrode 140 in the longitudinal direction. There are regions where the area occupancy of the charge transfer portion 141 for each region is larger than the region on the side.
　また、複数の開口部１４２の平面視における面積は、長尺方向におけるバスバー電極４０の中央及び両端のうちのどちらか一方に近いほど大きい。これにより、バスバー電極４０は、例えば、図８及び図１０に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極１４０の中央側の領域ほど、長尺方向におけるバスバー電極１４０の両端側の領域よりもそれぞれの領域に対する電荷伝達部１４１の面積占有率が大きくなる領域を有する。または、バスバー電極１４０は、例えば、図９に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極１４０の両端側の領域ほど、長尺方向におけるバスバー電極１４０の中央側の領域よりもそれぞれの領域に対する電荷伝達部１４１の面積占有率が大きくなる領域を有する。 Further, the area of the plurality of openings 142 in plan view is larger as it is closer to either the center or both ends of the bus bar electrode 40 in the longitudinal direction. As a result, the bus bar electrode 40 has a bus bar in the longitudinal direction that is closer to the center side of the bus bar electrode 140 in the longitudinal direction, such as the first region and the second region shown in FIGS. 8 and 10. It has a region where the area occupancy of the charge transfer portion 141 with respect to each region is larger than the regions on both ends of the electrode 140. Alternatively, the bus bar electrode 140 is, for example, as the first region and the second region shown in FIG. 9, the regions on both ends of the bus bar electrode 140 in the longitudinal direction are closer to the center of the bus bar electrode 140 in the longitudinal direction. There are regions where the area occupancy of the charge transfer portion 141 for each region is larger than the region on the side.
　なお、第１の領域及び第２の領域は、図８～１０に示される領域に限らず、図８～１０に示される領域とは異なる位置の領域であってもよい。 Note that the first region and the second region are not limited to the regions illustrated in FIGS. 8 to 10 and may be regions at positions different from the regions illustrated in FIGS.
　［２－２．効果等］
　本実施の形態に係る太陽電池モジュールは、隣り合う２つの太陽電池素子１１と、２つの太陽電池素子１１を電気的に接続する長尺状のタブ配線２０とを備える。２つの太陽電池素子１１のそれぞれは、タブ配線２０の長尺方向に沿って形成され、タブ配線２０と重なって接合する長尺状のバスバー電極１４０を有する。バスバー電極１４０は、太陽電池素子１１で生成された受光電荷をタブ配線２０に伝達する電荷伝達部１４１と、複数の開口部１４２とを有する。複数の開口部１４２は、長尺方向及び長尺方向と平面視において交差する交差方向に沿って並んで設けられ、複数の開口部１４２の交差方向に沿って並んで設けられる数は、長尺方向に沿って異なる。 [2-2. Effect]
The solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11. Each of the two solar cell elements 11 has a long bus bar electrode 140 that is formed along the long direction of the tab wiring 20 and is joined to the tab wiring 20 so as to overlap. The bus bar electrode 140 includes a charge transfer unit 141 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a plurality of openings 142. The plurality of openings 142 are provided side by side along the long direction and the crossing direction intersecting the long direction in plan view, and the number provided along the crossing direction of the plurality of openings 142 is long. Different along the direction.
　これにより、バスバー電極１４０は、例えば、図８～１０に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部１４１の面積占有率が異なる領域を有する。つまり、電荷伝達部１４１の面積占有率は、長尺方向に沿って不均一になる。言い換えると、バスバー電極１４０は、タブ配線２０と電荷伝達部１４１との接着強度が低い領域（第２の領域）と高い領域（第１の領域）とを有する。従来の太陽電池モジュールでは、タブ配線とバスバー電極とが接続しない部分が一様に設けられており、電気的ロスが一様に発生していた。一方、実施の形態２に係る太陽電池モジュールでは、タブ配線２０とバスバー電極１４０とが接続しない部分が不均一に設けられるため、電気的ロスを小さくしている。つまり、実施の形態２に係る太陽電池モジュールでは、タブ配線２０とバスバー電極１４０とが接続しない部分を場所によって小さくしているため、電気的ロスを小さくしている。したがって、温度サイクル等によりセル割れなどの不具合が発生するような状況になるまでは電気的ロスは抑制され、太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部１４１との接着強度が低い領域のタブ配線２０が剥がれる。これにより、タブ配線２０のバスバー電極１４０との接合が剥がれた領域にストレスを吸収させることができるため、以降は、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。また、タブ配線２０と電荷伝達部１４１との接着強度が高い領域では、タブ配線２０と電荷伝達部１４１とが接合しているため、集電効率の低下を抑制することができる。つまり、商品寿命内でのトータルの出力を高めた上で、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Thereby, the bus bar electrode 140 has regions having different area occupancy rates of the charge transfer portions 141 for the respective regions, such as the first region and the second region shown in FIGS. That is, the area occupancy of the charge transfer portion 141 becomes non-uniform along the longitudinal direction. In other words, the bus bar electrode 140 has a region (second region) where the adhesive strength between the tab wiring 20 and the charge transfer portion 141 is low (second region) and a region (first region). In the conventional solar cell module, the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly. On the other hand, in the solar cell module according to Embodiment 2, since the portion where the tab wiring 20 and the bus bar electrode 140 are not connected is provided unevenly, the electrical loss is reduced. That is, in the solar cell module according to Embodiment 2, since the portion where the tab wiring 20 and the bus bar electrode 140 are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 141 is low is peeled off. Thereby, since stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 140 is peeled off, the stress of the solar cell element 11 and the tab wiring 20 can be reduced thereafter. Further, in the region where the adhesive strength between the tab wiring 20 and the charge transfer portion 141 is high, since the tab wiring 20 and the charge transfer portion 141 are joined, it is possible to suppress a decrease in current collection efficiency. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
　また、バスバー電極１４０は、開口部１４２においてタブ配線２０と接合していない。したがって、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０のバスバー電極１４０と接合していない領域にストレスを吸収させることができるので、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Further, the bus bar electrode 140 is not joined to the tab wiring 20 at the opening 142. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region that is not joined to the bus bar electrode 140 of the tab wiring 20. The stress on the tab wiring 20 can be reduced.
　また、複数の開口部１４２が交差方向に沿って並んで設けられる数は、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方に近いほど多い。 In addition, the number of the plurality of openings 142 provided side by side along the crossing direction increases as the distance from the center and both ends of the bus bar electrode 140 in the longitudinal direction increases.
　また、複数の開口部１４２の平面視における面積は、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方に近いほど大きい。 Also, the area of the plurality of openings 142 in plan view is larger as it is closer to either the center or both ends of the bus bar electrode 140 in the longitudinal direction.
　これにより、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方側をタブ配線２０とバスバー電極１４０との接着強度が低い領域にすることができる。 Thereby, one of the center and both ends of the bus bar electrode 140 in the longitudinal direction can be an area where the adhesive strength between the tab wiring 20 and the bus bar electrode 140 is low.
　例えば、長尺方向におけるバスバー電極１４０の中央側をタブ配線２０とバスバー電極１４０との接着強度が低い領域にすることで、中央側でタブ配線２０を剥がれやすくすることができる。したがって、太陽電池素子１１とタブ配線２０との接合強度が高いと、温度サイクル等によるストレスの逃げ場がないので、太陽電池素子１１に対するストレスが高まるが、中央側でタブ配線２０が剥がれることで、太陽電池素子１１に対するストレスが緩和される。 For example, by setting the central side of the bus bar electrode 140 in the longitudinal direction to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 140 is low, the tab wiring 20 can be easily peeled off at the central side. Therefore, if the bonding strength between the solar cell element 11 and the tab wiring 20 is high, there is no escape from stress due to temperature cycles or the like, so the stress on the solar cell element 11 is increased, but the tab wiring 20 is peeled off at the center side. The stress on the solar cell element 11 is alleviated.
　また、例えば、長尺方向におけるバスバー電極１４０の両端側をタブ配線２０とバスバー電極１４０との接着強度が低い領域にすることで、両端側でタブ配線２０が剥がれやすくすることができる。したがって、タブ配線２０の両端での自由度が高まるので、タブ配線２０の両端でのストレスを低減できる。 In addition, for example, by setting both end sides of the bus bar electrode 140 in the longitudinal direction to regions where the adhesive strength between the tab wiring 20 and the bus bar electrode 140 is low, the tab wiring 20 can be easily peeled off at both end sides. Therefore, the degree of freedom at both ends of the tab wiring 20 is increased, so that stress at both ends of the tab wiring 20 can be reduced.
　なお、図８～１０に示される複数の開口部１４２の交差方向に沿って並んで設けられる数は、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方に近いほど多かったが、これに限らない。例えば、複数の開口部１４２の交差方向に沿って並んで設けられる数は、長尺方向に沿って異なればよく、長尺方向におけるバスバー電極１４０の中央及び両端のうちのどちらか一方から他方に向けて順番に多くならなくてもよい。つまり、バスバー電極１４０の中央及び両端のうちのどちらか一方の領域ではなく、バスバー電極１４０の任意の領域をタブ配線２０とバスバー電極１４０との接着強度が低い領域にしてもよい。これにより、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部１４１との接着強度が低い領域のタブ配線２０が剥がれる。したがって、タブ配線２０のバスバー電極１４０との接合が剥がれた領域にストレスを吸収させることができるため、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Although the number of the plurality of openings 142 shown in FIGS. 8 to 10 provided side by side along the crossing direction is closer to one of the center and both ends of the bus bar electrode 140 in the longitudinal direction, the number is larger. Not limited to this. For example, the number of the plurality of openings 142 provided side by side along the intersecting direction may be different along the longitudinal direction, from one of the center and both ends of the bus bar electrode 140 in the longitudinal direction to the other. It does not have to increase in order. That is, any area of the bus bar electrode 140 may be an area where the adhesive strength between the tab wiring 20 and the bus bar electrode 140 is low, instead of one of the center and both ends of the bus bar electrode 140. Thereby, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 141 is low is peeled off. Therefore, the stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 140 is peeled off, so that the stress of the solar cell element 11 and the tab wiring 20 can be reduced.
　また、交差方向に沿って隣り合う２つの開口部１４２の間隔は、交差方向におけるバスバー電極１４０の中央に近いほど大きい。 Also, the distance between the two openings 142 adjacent in the crossing direction is larger as the distance from the center of the bus bar electrode 140 in the crossing direction is closer.
　これにより、タブ配線２０とバスバー電極１４０との接合が、交差方向にずれた場合であっても、交差方向におけるバスバー電極１４０の中央に近い交差方向に沿って隣り合う２つの開口部１４２の間隔が大きいため、タブ配線２０と電荷伝達部１４１とが接合している面積の低下は抑制される。したがって、集電効率の低下を抑制することができる。 Thereby, even when the junction between the tab wiring 20 and the bus bar electrode 140 is shifted in the cross direction, the distance between the two openings 142 adjacent to each other along the cross direction close to the center of the bus bar electrode 140 in the cross direction. Therefore, a decrease in the area where the tab wiring 20 and the charge transfer portion 141 are joined is suppressed. Therefore, it is possible to suppress a decrease in current collection efficiency.
　（実施の形態３）
　次に、実施の形態３に係る太陽電池モジュールについて、図１１～１５を用いて説明する。 (Embodiment 3)
Next, a solar cell module according to Embodiment 3 will be described with reference to FIGS.
　本実施の形態に係る太陽電池モジュールは、隣り合う２つの太陽電池素子１１と、２つの太陽電池素子１１を電気的に接続する長尺状のタブ配線２０とを備える。２つの太陽電池素子１１のそれぞれは、タブ配線２０の長尺方向に沿って形成され、タブ配線２０と重なって接合する長尺状のバスバー電極２４０を有する。バスバー電極２４０は、太陽電池素子１１で生成された受光電荷をタブ配線２０に伝達する電荷伝達部２４１と、長尺方向と平面視において交差する交差方向に沿って並ぶ複数の領域に電荷伝達部２４１を分岐させる開口部２４２とを有する。ここで、電荷伝達部２４１における、開口部２４２によって交差方向に並ぶように分岐させられた領域を分岐部２４１ａと呼ぶ。 The solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11. Each of the two solar cell elements 11 has a long bus bar electrode 240 that is formed along the lengthwise direction of the tab wiring 20 and overlaps and is joined to the tab wiring 20. The bus bar electrode 240 includes a charge transfer unit 241 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20, and a charge transfer unit in a plurality of regions that are aligned along the crossing direction that intersects the long direction in plan view. And an opening 242 for branching 241. Here, the region branched in the crossing direction by the opening 242 in the charge transfer portion 241 is referred to as a branch portion 241a.
　このように、本実施の形態に係る太陽電池モジュールの構造、及び、太陽電池素子１１の構造については、実施の形態１に係るそれらと同様であるため詳細な説明を省略し、以下、実施の形態１と異なるバスバー電極２４０を中心に説明する。 Thus, since the structure of the solar cell module according to the present embodiment and the structure of the solar cell element 11 are the same as those according to the first embodiment, a detailed description thereof will be omitted. The bus bar electrode 240 different from that of the first embodiment will be mainly described.
　［３－１．実施の形態３に係るバスバー電極の構成］
　図１１及び図１２は、実施の形態３に係るバスバー電極２４０の構成の一例を示す平面図である。 [3-1. Configuration of Bus Bar Electrode According to Embodiment 3]
11 and 12 are plan views showing an example of the configuration of the bus bar electrode 240 according to the third embodiment.
　電荷伝達部２４１は、開口部２４２によって、交差方向に沿って並ぶ複数の分岐部２４１ａに分岐させられる。本実施の形態では、電荷伝達部２４１は、開口部２４２によって、交差方向に沿って並ぶ２つの分岐部２４１ａに分岐させられる。また、開口部２４２は、長尺方向におけるバスバー電極２４０の両端のうちの少なくとも一端に設けられた切り欠きであってもよい。また、分岐部２４１ａの交差方向の幅は、長尺方向に沿って変化する。なお、分岐部２４１ａの交差方向の幅は、長尺方向におけるバスバー電極２４０の中央及び両端のうちのどちらか一方から他方に向けて大きくなってもよい。 The charge transfer portion 241 is branched into a plurality of branch portions 241 a arranged along the crossing direction by the opening 242. In the present embodiment, the charge transfer portion 241 is branched into two branch portions 241 a arranged along the crossing direction by the opening 242. Further, the opening 242 may be a notch provided at at least one end of both ends of the bus bar electrode 240 in the longitudinal direction. Moreover, the width | variety of the crossing direction of the branch part 241a changes along a elongate direction. Note that the width of the branching portion 241a in the intersecting direction may increase from one of the center and both ends of the bus bar electrode 240 in the longitudinal direction toward the other.
　図１１では、バスバー電極２４０には、１つの開口部２４２が設けられる。開口部２４２は、図１１に示されるように、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極２４０の中央から両端に向けて大きくなるように設けられる。具体的には、開口部３４２は、長尺方向におけるバスバー電極２４０の中央から両端に向けて先細りになる形状を有する。これにより、分岐部２４１ａは、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極２４０の中央から両端に向けて大きくなるような逆テーパ形状を有する。 In FIG. 11, the bus bar electrode 240 is provided with one opening 242. As shown in FIG. 11, the opening 242 is provided so that the width in the intersecting direction of the branching portion 241 a increases from the center of the bus bar electrode 240 in the longitudinal direction toward both ends. Specifically, the opening 342 has a shape that tapers from the center of the bus bar electrode 240 toward both ends in the longitudinal direction. Thereby, the branch part 241a has a reverse taper shape in which the width in the intersecting direction of the branch part 241a increases from the center of the bus bar electrode 240 toward both ends in the longitudinal direction.
　図１２では、バスバー電極２４０には、長尺方向におけるバスバー電極２４０の両端のそれぞれに切り欠きとして開口部２４２が設けられる。開口部２４２は、図１２に示されるように、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極２４０の両端から中央に向けて大きくなるように設けられる。具体的には、開口部２４２は、長尺方向におけるバスバー電極２４０の両端から中央に向けて先細りになる形状を有する。これにより、分岐部２４１ａは、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極２４０の両端から中央に向けて大きくなるような逆テーパ形状を有する。 In FIG. 12, the bus bar electrode 240 is provided with openings 242 as notches at both ends of the bus bar electrode 240 in the longitudinal direction. As shown in FIG. 12, the opening 242 is provided such that the width of the branching portion 241a in the crossing direction increases from both ends of the bus bar electrode 240 toward the center in the longitudinal direction. Specifically, the opening 242 has a shape that tapers from both ends of the bus bar electrode 240 toward the center in the longitudinal direction. Thereby, the branch part 241a has a reverse taper shape in which the width in the crossing direction of the branch part 241a increases from both ends of the bus bar electrode 240 toward the center in the longitudinal direction.
　このように、バスバー電極２４０は、交差方向の幅が長尺方向に沿って不均一な開口部２４２を有する。言い換えると、バスバー電極２４０は、交差方向の幅が長尺方向に沿って不均一な分岐部２４１ａを有する。これにより、バスバー電極２４０は、例えば、図１１及び図１２に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部２４１の面積占有率が異なる領域を有する。例えば、第１の領域における電荷伝達部２４１の面積占有率は、第２の領域における電荷伝達部２４１の面積占有率よりも大きい。ただし、第１の領域及び第２の領域の大きさは、それぞれ同じ大きさを有する。また、第１の領域及び第２の領域の大きさは、所定の大きさ以上である必要がある。例えば、所定の大きさは、開口部２４２の一部及び交差方向におけるバスバー電極２４０の両端を含む大きさである。 Thus, the bus bar electrode 240 has the opening 242 whose width in the crossing direction is not uniform along the longitudinal direction. In other words, the bus bar electrode 240 has a branch portion 241a whose width in the intersecting direction is not uniform along the longitudinal direction. Accordingly, the bus bar electrode 240 has regions having different area occupancy rates of the charge transfer portions 241 for the respective regions, such as the first region and the second region illustrated in FIGS. 11 and 12, for example. For example, the area occupancy of the charge transfer unit 241 in the first region is larger than the area occupancy of the charge transfer unit 241 in the second region. However, the first region and the second region have the same size. Further, the size of the first region and the second region needs to be equal to or larger than a predetermined size. For example, the predetermined size is a size including a part of the opening 242 and both ends of the bus bar electrode 240 in the crossing direction.
　また、分岐部２４１ａの交差方向の幅は、長尺方向におけるバスバー電極２４０の中央及び両端のうちのどちらか一方から他方に向けて大きくなる。これにより、バスバー電極２４０は、例えば、図１１に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極２４０の両端側の第１の領域ほど、長尺方向におけるバスバー電極２４０の中央側の第２の領域よりもそれぞれの領域に対する電荷伝達部２４１の面積占有率が大きい領域を有する。または、バスバー電極２４０は、例えば、図１２に示される第１の領域及び第２の領域のように、長尺方向におけるバスバー電極２４０の中央側の第１の領域ほど、長尺方向におけるバスバー電極２４０の両端側の第２の領域よりもそれぞれの領域に対する電荷伝達部２４１の面積占有率が大きい領域を有する。 Further, the width of the branching portion 241a in the crossing direction increases from one of the center and both ends of the bus bar electrode 240 in the long direction toward the other. Thereby, the bus bar electrode 240 is, for example, the first region on both ends of the bus bar electrode 240 in the longitudinal direction as in the first region and the second region shown in FIG. The region having a larger area occupancy ratio of the charge transfer portion 241 for each region than the second region on the center side of the electrode 240 is provided. Alternatively, the bus bar electrode 240 is, for example, the first region on the central side of the bus bar electrode 240 in the longitudinal direction as in the first region and the second region shown in FIG. The area occupying area of the charge transfer portion 241 with respect to each region is larger than the second regions on both ends of 240.
　なお、第１の領域及び第２の領域は、図１１及び図１２に示される領域に限らず、図１１及び図１２に示される領域とは異なる位置の領域であってもよい。 Note that the first region and the second region are not limited to the regions illustrated in FIGS. 11 and 12, and may be regions at positions different from the regions illustrated in FIGS. 11 and 12.
　［３－２．実施の形態３の変形例に係るバスバー電極の構成］
　図１３及び図１４は、実施の形態３の変形例に係るバスバー電極２４０ａの構成の一例を示す平面図である。 [3-2. Configuration of Bus Bar Electrode According to Modified Example of Embodiment 3]
13 and 14 are plan views showing an example of the configuration of the bus bar electrode 240a according to a modification of the third embodiment.
　本変形例に係るバスバー電極２４０ａの構成は、図１１及び図１２に示されるバスバー電極２４０の構成と比較して、分岐部２４１ａが交差方向に沿って３つ以上並ぶ点が異なる。以下では、図１１及び図１２に示されるバスバー電極２４０の構成と同じ点は詳細な説明を省略し、異なる点を中心に説明する。 The configuration of the bus bar electrode 240a according to the present modification is different from the configuration of the bus bar electrode 240 shown in FIGS. 11 and 12 in that three or more branch portions 241a are arranged along the crossing direction. Hereinafter, detailed description of the same points as the configuration of the bus bar electrode 240 shown in FIGS. 11 and 12 will be omitted, and different points will be mainly described.
　図１３に示されるバスバー電極２４０ａでは、開口部２４２は、長尺方向における開口部２４２の両端のそれぞれに、電荷伝達部２４１を交差方向に沿って並ぶ４つの分岐部２４１ａに分岐させる形状を有する。具体的には、開口部２４２は、長尺方向における開口部２４２の両端のそれぞれに、長尺方向におけるバスバー電極２４０の中央から両端に向けて先細りになる部分が交差方向に沿って３つ並ぶ形状を有する。これにより、交差方向に沿って並ぶ４つの分岐部２４１ａは、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極２４０の中央から両端に向けて大きくなるような逆テーパ形状を有する。なお、開口部２４２は、電荷伝達部２４１を交差方向に沿って並ぶ３つ又は５つ以上の分岐部２４１ａに分岐させる形状を有してもよい。具体的には、開口部２４２は、長尺方向における開口部２４２の両端のそれぞれに、長尺方向におけるバスバー電極２４０の中央から両端に向けて先細りになる部分が交差方向に沿って２つ又は４つ以上並ぶ形状を有してもよい。これにより、交差方向に沿って並ぶ３つ又は５つ以上の分岐部２４１ａは、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極２４０の中央から両端に向けて大きくなるような逆テーパ形状を有してもよい。 In the bus bar electrode 240a shown in FIG. 13, the opening 242 has a shape that branches the charge transfer part 241 into four branch parts 241a arranged along the crossing direction at both ends of the opening 242 in the longitudinal direction. . Specifically, in the opening 242, three portions that taper from the center of the bus bar electrode 240 toward both ends in the longitudinal direction are arranged along the crossing direction at each of both ends of the opening 242 in the longitudinal direction. Has a shape. Thus, the four branch portions 241a arranged along the cross direction have reverse tapered shapes such that the width of the branch portion 241a in the cross direction increases from the center of the bus bar electrode 240 toward both ends in the longitudinal direction. The opening 242 may have a shape that branches the charge transfer portion 241 into three or five or more branch portions 241a arranged along the crossing direction. Specifically, the opening portion 242 has two portions that taper from the center of the bus bar electrode 240 in the longitudinal direction toward both ends at each of both ends of the opening portion 242 in the longitudinal direction. It may have a shape of four or more. As a result, the three or five or more branch portions 241a arranged along the intersecting direction have a reverse taper such that the width of the branch portion 241a in the intersecting direction increases from the center of the bus bar electrode 240 toward both ends in the longitudinal direction. You may have a shape.
　図１４に示されるバスバー電極２４０ａでは、電荷伝達部２４１は、長尺方向におけるバスバー電極２４０ａの両端のそれぞれにおいて、交差方向に沿って並ぶ２つの開口部（切り欠き）２４２によって、交差方向に沿って並ぶ３つの分岐部２４１ａに分岐させられる。具体的には、交差方向に沿って並ぶ２つの開口部２４２は、長尺方向におけるバスバー電極２４０の両端から中央に向けて先細りになる形状を有する。これにより、交差方向に沿って並ぶ３つの分岐部２４１ａは、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極１４０の両端から中央に向けて大きくなるような逆テーパ形状を有する。なお、開口部２４２は、長尺方向におけるバスバー電極２４０ａの両端のそれぞれにおいて、電荷伝達部２４１を交差方向に沿って並ぶ４つ以上の分岐部２４１ａに分岐させるために、交差方向に沿って３つ以上並ぶように設けられてもよい。具体的には、長尺方向におけるバスバー電極２４０ａの両端のそれぞれにおいて、長尺方向におけるバスバー電極２４０ａの両端から中央に向けて先細りになる形状を有する開口部２４２が、交差方向に沿って３つ以上並ぶように設けられてもよい。これにより、交差方向に沿って並ぶ４つ以上の分岐部２４１ａは、分岐部２４１ａの交差方向の幅が長尺方向におけるバスバー電極２４０の両端から中央に向けて大きくなるような逆テーパ形状を有してもよい。 In the bus bar electrode 240a shown in FIG. 14, the charge transfer portion 241 extends along the cross direction by two openings (notches) 242 arranged along the cross direction at each of both ends of the bus bar electrode 240a in the longitudinal direction. Are branched into three branch portions 241a arranged side by side. Specifically, the two openings 242 aligned along the intersecting direction have a shape that tapers from both ends of the bus bar electrode 240 toward the center in the longitudinal direction. As a result, the three branch portions 241a arranged along the cross direction have reverse tapered shapes such that the width of the branch portion 241a in the cross direction increases from both ends of the bus bar electrode 140 toward the center in the longitudinal direction. Note that the opening 242 is formed along the cross direction in order to branch the charge transfer portion 241 into four or more branch portions 241a arranged along the cross direction at both ends of the bus bar electrode 240a in the longitudinal direction. Two or more may be provided. Specifically, at each of both ends of the bus bar electrode 240a in the longitudinal direction, there are three openings 242 having a shape that tapers from both ends of the bus bar electrode 240a in the longitudinal direction toward the center. You may provide so that it may line up. As a result, the four or more branch portions 241a arranged along the intersecting direction have a reverse taper shape in which the width of the intersecting direction of the branch portion 241a increases from both ends of the bus bar electrode 240 toward the center in the longitudinal direction. May be.
　なお、図１４に示されるバスバー電極２４０ａのように、バスバー電極２４０ａの交差方向の幅が、長尺方向に沿って変化してもよい。例えば、バスバー電極２４０ａは、長尺方向におけるバスバー電極２４０ａの両端から中央に向けて大きくなるような逆テーパ形状を有してもよい。 In addition, like the bus bar electrode 240a shown in FIG. 14, the width in the crossing direction of the bus bar electrode 240a may change along the longitudinal direction. For example, the bus bar electrode 240a may have a reverse tapered shape that increases from both ends of the bus bar electrode 240a in the longitudinal direction toward the center.
　このように、バスバー電極２４０ａは、交差方向の幅が長尺方向に沿って変化する分岐部２４１ａを、交差方向に沿って３つ以上並ぶように有する。なお、バスバー電極２４０ａが分岐部２４１ａを交差方向に沿って３つ以上並ぶように有する場合であっても、図１１及び図１２と同様に、バスバー電極２４０ａは、例えば、図１３及び図１４に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部２４１の面積占有率が異なる領域を有する。 Thus, the bus bar electrode 240a has three or more branching portions 241a whose width in the crossing direction changes along the longitudinal direction so as to be arranged in the crossing direction. Even when the bus bar electrode 240a has three or more branching portions 241a arranged in the crossing direction, the bus bar electrode 240a is, for example, as shown in FIGS. Like the first region and the second region shown, there are regions where the area occupancy rates of the charge transfer portions 241 with respect to the respective regions are different.
　［３－３．効果等］
　本実施の形態に係る太陽電池モジュールは、隣り合う２つの太陽電池素子１１と、２つの太陽電池素子１１を電気的に接続する長尺状のタブ配線２０とを備える。２つの太陽電池素子１１のそれぞれは、タブ配線２０の長尺方向に沿って形成され、タブ配線２０と重なって接合する長尺状のバスバー電極２４０（２４０ａ）を有する。バスバー電極２４０（２４０ａ）は、太陽電池素子１１で生成された受光電荷をタブ配線２０に伝達する電荷伝達部２４１と、長尺方向と平面視において交差する方向である交差方向に沿って並ぶ複数の分岐部２４１ａに電荷伝達部２４１を分岐させる開口部２４２とを有する。分岐部２４１ａの交差方向の幅は、長尺方向に沿って変化する。 [3-3. Effect]
The solar cell module according to the present embodiment includes two adjacent solar cell elements 11 and a long tab wiring 20 that electrically connects the two solar cell elements 11. Each of the two solar cell elements 11 has a long bus bar electrode 240 (240a) that is formed along the lengthwise direction of the tab wiring 20 and overlaps and is joined to the tab wiring 20. A plurality of bus bar electrodes 240 (240a) are arranged along a crossing direction, which is a direction crossing the long direction in a plan view, with a charge transfer unit 241 that transmits the received light charges generated by the solar cell element 11 to the tab wiring 20. The branch portion 241a has an opening 242 for branching the charge transfer portion 241. The width of the branching portion 241a in the intersecting direction changes along the longitudinal direction.
　これにより、バスバー電極２４０（２４０ａ）は、例えば、図１１～１４に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部２４１の面積占有率が異なる領域を有する。つまり、電荷伝達部２４１の面積占有率は、長尺方向に沿って不均一になる。言い換えると、バスバー電極２４０（２４０ａ）は、タブ配線２０と電荷伝達部２４１との接着強度が低い領域（第２の領域）と高い領域（第１の領域）とを有する。従来の太陽電池モジュールでは、タブ配線とバスバー電極とが接続しない部分が一様に設けられており、電気的ロスが一様に発生していた。一方、実施の形態３に係る太陽電池モジュールでは、タブ配線２０とバスバー電極２４０（２４０ａ）とが接続しない部分が不均一に設けられるため、電気的ロスを小さくしている。つまり、実施の形態３に係る太陽電池モジュールでは、タブ配線２０とバスバー電極２４０（２４０ａ）とが接続しない部分を場所によって小さくしているため、電気的ロスを小さくしている。したがって、温度サイクル等によりセル割れなどの不具合が発生するような状況になるまでは電気的ロスは抑制され、太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部２４１との接着強度が低い領域のタブ配線２０が剥がれる。これにより、タブ配線２０のバスバー電極２４０との接合が剥がれた領域にストレスを吸収させることができるため、以降は、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。また、タブ配線２０と電荷伝達部２４１との接着強度が高い領域では、タブ配線２０と電荷伝達部２４１とが接合しているため、集電効率の低下を抑制することができる。 As a result, the bus bar electrode 240 (240a) has regions having different area occupancy rates of the charge transfer portions 241 for the respective regions, such as the first region and the second region shown in FIGS. . That is, the area occupation ratio of the charge transfer portion 241 becomes non-uniform along the long direction. In other words, the bus bar electrode 240 (240a) includes a region (second region) where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low (second region) and a region (first region). In the conventional solar cell module, the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly. On the other hand, in the solar cell module according to Embodiment 3, since the portion where the tab wiring 20 and the bus bar electrode 240 (240a) are not connected is provided unevenly, the electrical loss is reduced. That is, in the solar cell module according to Embodiment 3, since the portion where the tab wiring 20 and the bus bar electrode 240 (240a) are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 241 is low is peeled off. Thereby, since stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 240 is peeled off, the stress of the solar cell element 11 and the tab wiring 20 can be reduced thereafter. Further, in the region where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is high, since the tab wiring 20 and the charge transfer portion 241 are joined, it is possible to suppress a decrease in current collection efficiency.
　また、バスバー電極２４０（２４０ａ）は、開口部２４２においてタブ配線２０と接合していない。したがって、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０のバスバー電極２４０（２４０ａ）と接合していない領域にストレスを吸収させることができるので、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。つまり、商品寿命内でのトータルの出力を高めた上で、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Further, the bus bar electrode 240 (240a) is not joined to the tab wiring 20 at the opening 242. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region of the tab wiring 20 that is not joined to the bus bar electrode 240 (240a). The stress of the element 11 and the tab wiring 20 can be reduced. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
　また、開口部２４２は、例えば、電荷伝達部２４１を交差方向に沿って３つ以上並ぶ分岐部２４１ａに分岐させる。これにより、開口部２４２が電荷伝達部２４１を細かく分岐させるため、タブ配線２０と電荷伝達部２４１とが接合する面積は増える。したがって、集電効率の低下を抑制することができる。 Further, the opening 242 branches, for example, the charge transfer portion 241 into the branch portions 241a arranged in the three or more directions along the crossing direction. As a result, the opening 242 branches the charge transfer portion 241 finely, so that the area where the tab wiring 20 and the charge transfer portion 241 are joined increases. Therefore, it is possible to suppress a decrease in current collection efficiency.
　また、開口部２４２は、長尺方向におけるバスバー電極２４０の両端のうちの少なくとも一端に設けられた切り欠きである。 The opening 242 is a notch provided at at least one end of both ends of the bus bar electrode 240 in the longitudinal direction.
　これにより、開口部２４２が電荷伝達部２４１を切り欠いた切り欠きであっても、バスバー電極２４０（２４０ａ）は、例えば、図１２及び図１４に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部２４１の面積占有率が異なる領域を有する。つまり、電荷伝達部２４１の面積占有率は、長尺方向に沿って不均一になる。言い換えると、バスバー電極２４０（２４０ａ）は、タブ配線２０と電荷伝達部２４１との接着強度が低い領域（第２の領域）と高い領域（第１の領域）とを有する。したがって、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部２４１との接着強度が低い領域のタブ配線２０が剥がれるため、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 As a result, even if the opening 242 is a cutout formed by cutting out the charge transfer portion 241, the bus bar electrode 240 (240a) is formed in, for example, the first region and the second region shown in FIGS. As described above, there are regions in which the area occupancy ratios of the charge transfer portions 241 with respect to the respective regions are different. That is, the area occupation ratio of the charge transfer portion 241 becomes non-uniform along the long direction. In other words, the bus bar electrode 240 (240a) includes a region (second region) where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low (second region) and a region (first region). Accordingly, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low is peeled off. The stress on the tab wiring 20 can be reduced.
　また、分岐部２４１ａの交差方向の幅は、長尺方向におけるバスバー電極２４０（２４０ａ）の中央及び両端のうちのどちらか一方から他方に向けて大きくなる。 Also, the width of the branching portion 241a in the intersecting direction increases from one of the center and both ends of the bus bar electrode 240 (240a) in the longitudinal direction toward the other.
　これにより、長尺方向におけるバスバー電極２４０（２４０ａ）の中央及び両端のうちのどちらか一方側をタブ配線２０とバスバー電極２４０（２４０ａ）との接着強度が低い領域にすることができる。 Thereby, either one of the center and both ends of the bus bar electrode 240 (240a) in the longitudinal direction can be set to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 240 (240a) is low.
　例えば、長尺方向におけるバスバー電極２４０（２４０ａ）の中央側をタブ配線２０とバスバー電極２４０（２４０ａ）との接着強度が低い領域にすることで、中央側でタブ配線２０を剥がれやすくすることができる。したがって、太陽電池素子１１とタブ配線２０との接合強度が高いと、温度サイクル等によるストレスの逃げ場がないので、太陽電池素子１１に対するストレスが高まるが、中央側でタブ配線２０が剥がれることで、太陽電池素子１１に対するストレスが緩和される。 For example, by making the central side of the bus bar electrode 240 (240a) in the longitudinal direction an area where the adhesive strength between the tab wiring 20 and the bus bar electrode 240 (240a) is low, the tab wiring 20 can be easily peeled off at the central side. it can. Therefore, if the bonding strength between the solar cell element 11 and the tab wiring 20 is high, there is no escape from stress due to temperature cycles or the like, so the stress on the solar cell element 11 is increased, but the tab wiring 20 is peeled off at the center side. The stress on the solar cell element 11 is alleviated.
　また、例えば、長尺方向におけるバスバー電極２４０（２４０ａ）の両端側をタブ配線２０とバスバー電極２４０（２４０ａ）との接着強度が低い領域にすることで、両端側でタブ配線２０が剥がれやすくすることができる。したがって、タブ配線２０の両端での自由度が高まるので、タブ配線２０の両端でのストレスを低減できる。 Further, for example, by setting the both ends of the bus bar electrode 240 (240a) in the longitudinal direction to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 240 (240a) is low, the tab wiring 20 is easily peeled off at both ends. be able to. Therefore, the degree of freedom at both ends of the tab wiring 20 is increased, so that stress at both ends of the tab wiring 20 can be reduced.
　また、これにより、長尺方向におけるバスバー電極２４０（２４０ａ）の中央及び両端のうちのどちらか一方から他方に向けて、単位長さあたりの抵抗値を小さくすることができる。ここで、タブ配線２０とバスバー電極２４０（２４０ａ）とが剥がれた場合の太陽電池素子１１における受光電荷の流れを、図１５を用いて説明する。 Further, this makes it possible to reduce the resistance value per unit length from one of the center and both ends of the bus bar electrode 240 (240a) in the longitudinal direction toward the other. Here, the flow of received light charges in the solar cell element 11 when the tab wiring 20 and the bus bar electrode 240 (240a) are peeled will be described with reference to FIG.
　図１５は、実施の形態３及びその変形例に係る太陽電池素子１１における受光電荷の流れを説明する模式図である。図１５は、図１２のバスバー電極１４０におけるＸＶ－ＸＶから見た図である。ただし、図１５には、バスバー電極２４０の周囲の構成についても示されている。また、図１５に示される矢印は、受光電荷の流れを示しており、矢印が太いほど受光電荷の量が多いことを示している。 FIG. 15 is a schematic diagram for explaining the flow of received light charges in the solar cell element 11 according to Embodiment 3 and its modification. FIG. 15 is a view as seen from XV-XV in the bus bar electrode 140 of FIG. However, FIG. 15 also shows the configuration around the bus bar electrode 240. Further, the arrows shown in FIG. 15 indicate the flow of received light charges, and the thicker the arrows, the greater the amount of received light charges.
　タブ配線２０とバスバー電極２４０とが剥がれていない場合、太陽電池素子１１で発生した受光電荷は、フィンガー電極５０で集電される。そして、フィンガー電極５０で集電された受光電荷は、バスバー電極２４０へ伝達され、さらに、バスバー電極２４０の直上に接合されたタブ配線２０へ伝達される。 When the tab wiring 20 and the bus bar electrode 240 are not peeled off, the received charge generated in the solar cell element 11 is collected by the finger electrode 50. The light-receiving charges collected by the finger electrode 50 are transmitted to the bus bar electrode 240 and further transmitted to the tab wiring 20 joined immediately above the bus bar electrode 240.
　一方、タブ配線２０とバスバー電極２４０の一部とが剥がれている場合、太陽電池素子１１で発生した受光電荷は、フィンガー電極５０で集電される。そして、フィンガー電極５０で集電された受光電荷は、バスバー電極２４０へ伝達される。しかし、タブ配線２０とバスバー電極２４０の一部とが剥がれているため、バスバー電極２４０へ伝達された受光電荷は、タブ配線２０とバスバー電極２４０とが剥がれていない箇所までバスバー電極２４０を流れる。このとき、バスバー電極２４０へ伝達された受光電荷は、各フィンガー電極で集電された受光電荷が加わりながら、タブ配線２０とバスバー電極２４０とが剥がれていない箇所までバスバー電極２４０を流れる。つまり、図１５に示される矢印のように、バスバー電極２４０とフィンガー電極５０とが交差する毎に受光電荷の量が多くなる。したがって、受光電荷の量が多いほどバスバー電極２４０が有する抵抗成分による電力の損失が大きくなってしまう。 On the other hand, when the tab wiring 20 and a part of the bus bar electrode 240 are peeled off, the received charge generated in the solar cell element 11 is collected by the finger electrode 50. The received charge collected by the finger electrode 50 is transmitted to the bus bar electrode 240. However, since the tab wiring 20 and a part of the bus bar electrode 240 are peeled off, the received light charge transmitted to the bus bar electrode 240 flows through the bus bar electrode 240 to a position where the tab wiring 20 and the bus bar electrode 240 are not peeled off. At this time, the received charge transmitted to the bus bar electrode 240 flows through the bus bar electrode 240 to a portion where the tab wiring 20 and the bus bar electrode 240 are not peeled off while the received charge collected by each finger electrode is added. That is, as shown by the arrows in FIG. 15, the amount of received light charges increases each time the bus bar electrode 240 and the finger electrode 50 intersect. Therefore, the greater the amount of received light charge, the greater the power loss due to the resistance component of the bus bar electrode 240.
　そこで、分岐部２４１ａの交差方向の幅を長尺方向におけるバスバー電極２４０（２４０ａ）の中央及び両端のうちのどちらか一方から他方に向けて大きくする。これにより、バスバー電極２４０（２４０ａ）の単位長さあたりの抵抗値を、バスバー電極２４０（２４０ａ）の中央及び両端のうちのどちらか一方から他方に向けて小さくすることができる。例えば、図１２に示されるように、分岐部２４１ａの交差方向の幅を長尺方向におけるバスバー電極２４０の両端から中央に向けて大きくする（Ｗ１＜Ｗ２＜Ｗ３）。これにより、バスバー電極２４０の単位長さあたりの抵抗値が長尺方向におけるバスバー電極２４０の両端から中央に向けて小さくなる。 Therefore, the width of the branching portion 241a in the crossing direction is increased from one of the center and both ends of the bus bar electrode 240 (240a) in the long direction toward the other. Thereby, the resistance value per unit length of the bus bar electrode 240 (240a) can be decreased from one of the center and both ends of the bus bar electrode 240 (240a) toward the other. For example, as shown in FIG. 12, the width of the branching portion 241a in the intersecting direction is increased from both ends of the bus bar electrode 240 in the longitudinal direction toward the center (W1 <W2 <W3). Thereby, the resistance value per unit length of the bus bar electrode 240 decreases from the both ends of the bus bar electrode 240 in the longitudinal direction toward the center.
　これにより、タブ配線２０とバスバー電極２４０（２４０ａ）とが剥がれている領域において、バスバー電極２４０（２４０ａ）が有する抵抗成分による電力の損失を抑制することができる。 Thereby, in the region where the tab wiring 20 and the bus bar electrode 240 (240a) are peeled off, power loss due to the resistance component of the bus bar electrode 240 (240a) can be suppressed.
　なお、図１１～１４に示される分岐部２４１ａの交差方向の幅は、長尺方向におけるバスバー電極２４０の中央及び両端のうちのどちらか一方から他方に向けて大きくなったが、これに限らない。例えば、分岐部２４１ａの交差方向の幅が長尺方向に沿って変化すればよく、長尺方向におけるバスバー電極２４０（２４０ａ）の中央及び両端のうちのどちらか一方から他方に向けて大きくならなくてもよい。つまり、バスバー電極２４０（２４０ａ）の中央及び両端のうちのどちらか一方の領域ではなく、バスバー電極２４０（２４０ａ）の任意の領域をタブ配線２０とバスバー電極２４０（２４０ａ）との接着強度が低い領域にしてもよい。これにより、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部２４１との接着強度が低い領域のタブ配線２０が剥がれる。したがって、タブ配線２０のバスバー電極２４０（２４０ａ）との接合が剥がれた領域にストレスを吸収させることができるため、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 The width of the branching portion 241a shown in FIGS. 11 to 14 is increased from one of the center and both ends of the bus bar electrode 240 toward the other in the longitudinal direction, but is not limited thereto. . For example, the width in the intersecting direction of the branch portion 241a only needs to change along the longitudinal direction, and does not increase from one of the center and both ends of the bus bar electrode 240 (240a) in the longitudinal direction toward the other. May be. That is, the adhesive strength between the tab wiring 20 and the bus bar electrode 240 (240a) is low in any region of the bus bar electrode 240 (240a), not in one of the center and both ends of the bus bar electrode 240 (240a). It may be an area. Thereby, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the tab wiring 20 in a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low is peeled off. Therefore, the stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 240 (240a) is peeled off, so that the stress of the solar cell element 11 and the tab wiring 20 can be reduced.
　また、バスバー電極２４０（２４０ａ）の交差方向の幅は、長尺方向に沿って変化する。 Further, the width of the bus bar electrode 240 (240a) in the intersecting direction changes along the longitudinal direction.
　これにより、バスバー電極２４０（２４０ａ）の交差方向の幅、つまり、電荷伝達部２４１の交差方向における上端と下端との間の幅を長尺方向に沿って変化させることで、開口部２４２の形状を変化させなくても、タブ配線２０と電荷伝達部２４１との接着強度が低い領域と高い領域とを作ることができる。 Thereby, the width of the bus bar electrode 240 (240a) in the crossing direction, that is, the width between the upper end and the lower end in the crossing direction of the charge transfer unit 241 is changed along the longitudinal direction, thereby forming the shape of the opening 242. Even without changing, it is possible to create a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 241 is low and a region where it is high.
　（実施の形態４）
　次に、実施の形態４に係る太陽電池モジュールについて、図１６～１８を用いて説明する。 (Embodiment 4)
Next, a solar cell module according to Embodiment 4 will be described with reference to FIGS.
　本実施の形態に係る太陽電池モジュールの構造、及び、太陽電池素子１１の構造については、実施の形態３に係るそれらと同様であるため詳細な説明を省略し、以下、実施の形態３と異なるバスバー電極３４０を中心に説明する。 Since the structure of the solar cell module according to the present embodiment and the structure of the solar cell element 11 are the same as those according to the third embodiment, a detailed description thereof will be omitted, and hereinafter, different from the third embodiment. The description will focus on the bus bar electrode 340.
　［４－１．実施の形態４に係るバスバー電極の構成］
　図１６～１８は、実施の形態４に係るバスバー電極３４０の構成の一例を示す平面図である。 [4-1. Configuration of Bus Bar Electrode According to Embodiment 4]
16 to 18 are plan views showing an example of the configuration of the bus bar electrode 340 according to the fourth embodiment.
　バスバー電極３４０は、開口部３４２を複数有する。開口部３４２は、長尺方向に沿って並んで設けられる。なお、分岐部３４１ａの交差方向の幅は、長尺方向における開口部３４２の中央及び両端のうちのどちらか一方から他方に向けて大きくなってもよい。 The bus bar electrode 340 has a plurality of openings 342. The openings 342 are provided side by side along the longitudinal direction. Note that the width of the branching portion 341a in the intersecting direction may increase from one of the center and both ends of the opening 342 in the longitudinal direction toward the other.
　図１６及び図１７では、バスバー電極３４０には、図１１及び図１３に示される開口部２４２の形状と類似した開口部３４２が、長尺方向に沿って４つ並んで設けられる。図１６及び図１７に示されるように、開口部３４２は、分岐部３４１ａの交差方向の幅が長尺方向における開口部３４２の両端から中央に向けて大きくなるように設けられる。具体的には、開口部３４２は、長尺方向における開口部３４２の中央から両端に向けて先細りになる形状を有する。これにより、バスバー電極３４０は、分岐部３４１ａの交差方向の幅が長尺方向における開口部３４２の中央から両端に向けて大きくなるような逆テーパ形状を有する分岐部３４１ａを開口部３４２毎に有する。 16 and 17, the bus bar electrode 340 is provided with four openings 342 similar to the shape of the opening 242 shown in FIGS. 11 and 13 along the longitudinal direction. As shown in FIGS. 16 and 17, the opening 342 is provided such that the width in the intersecting direction of the branching portion 341 a increases from both ends of the opening 342 in the longitudinal direction toward the center. Specifically, the opening 342 has a shape that tapers from the center of the opening 342 in the longitudinal direction toward both ends. As a result, the bus bar electrode 340 has, for each opening 342, a branching part 341a having a reverse taper shape in which the width in the crossing direction of the branching part 341a increases from the center of the opening 342 toward both ends in the longitudinal direction. .
　図１８では、バスバー電極３４０には、円形の形状の開口部３４２が４つ設けられる。図１８に示されるように、開口部３４２は、長尺方向に沿って並んで設けられ、開口部３４２が円形の形状を有することで分岐部３４１ａの交差方向の幅が長尺方向における開口部３４２の両端から中央に向けて大きくなるように設けられる。これにより、バスバー電極３４０は、分岐部３４１ａの交差方向の幅が長尺方向における開口部３４２の中央から両端に向けて大きくなるような逆テーパ形状を有する分岐部３４１ａを開口部３４２毎に有する。 In FIG. 18, the bus bar electrode 340 is provided with four circular openings 342. As shown in FIG. 18, the openings 342 are provided side by side along the longitudinal direction, and the opening 342 has a circular shape, so that the width in the intersecting direction of the branching part 341 a is the opening in the longitudinal direction. It is provided so as to increase from both ends of 342 toward the center. As a result, the bus bar electrode 340 has, for each opening 342, a branching part 341a having a reverse tapered shape such that the width of the branching part 341a in the crossing direction increases from the center of the opening 342 toward both ends in the longitudinal direction. .
　このように、バスバー電極３４０は、交差方向の幅が長尺方向に沿って不均一な開口部３４２を複数有する。言い換えると、バスバー電極３４０は、交差方向の幅が長尺方向に沿って不均一な分岐部３４１ａを複数有する。これにより、バスバー電極３４０は、例えば、図１６～１８に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部３４１の面積占有率が異なる領域を有する。例えば、第１の領域における電荷伝達部３４１の面積占有率は、第２の領域における電荷伝達部３４１の面積占有率よりも大きい。ただし、第１の領域及び第２の領域の大きさは、それぞれ同じ大きさを有する。また、第１の領域及び第２の領域の大きさは、所定の大きさ以上である必要がある。例えば、所定の大きさは、開口部３４２の一部及び交差方向におけるバスバー電極３４０の両端を含む大きさである。 Thus, the bus bar electrode 340 has a plurality of openings 342 whose width in the intersecting direction is not uniform along the longitudinal direction. In other words, the bus bar electrode 340 has a plurality of branch portions 341a whose width in the crossing direction is not uniform along the longitudinal direction. Accordingly, the bus bar electrode 340 includes regions having different area occupancy rates of the charge transfer portions 341 for the respective regions, such as the first region and the second region illustrated in FIGS. For example, the area occupancy of the charge transfer unit 341 in the first region is larger than the area occupancy of the charge transfer unit 341 in the second region. However, the first region and the second region have the same size. Further, the size of the first region and the second region needs to be equal to or larger than a predetermined size. For example, the predetermined size is a size including a part of the opening 342 and both ends of the bus bar electrode 340 in the crossing direction.
　また、分岐部３４１ａの交差方向の幅は、長尺方向における開口部３４２の中央及び両端のうちのどちらか一方から他方に向けて大きくなる。これにより、バスバー電極３４０は、例えば、図１６～１８に示される第１の領域及び第２の領域のように、長尺方向における開口部３４２の両端側の第１の領域ほど、長尺方向における開口部３４２の中央側の第２の領域よりもそれぞれの領域に対する電荷伝達部３４１の面積占有率が大きい領域を有する。 Also, the width of the branching portion 341a in the intersecting direction increases from one of the center and both ends of the opening 342 in the longitudinal direction toward the other. As a result, the bus bar electrode 340 is formed so that the first region on both ends of the opening 342 in the longitudinal direction is longer in the longitudinal direction, such as the first region and the second region shown in FIGS. The area occupying area of the charge transfer portion 341 in each region is larger than the second region on the center side of the opening 342 in FIG.
　なお、第１の領域及び第２の領域は、図１６～１８に示される領域に限らず、図１６～１８に示される領域とは異なる位置の領域であってもよい。 Note that the first region and the second region are not limited to the regions illustrated in FIGS. 16 to 18 and may be regions at positions different from the regions illustrated in FIGS.
　また、図１６～１８に示される分岐部３４１ａの交差方向の幅は、長尺方向における開口部３４２の中央及び両端のうちのどちらか一方から他方に向けて大きくなったが、これに限らない。例えば、分岐部３４１ａの交差方向の幅が長尺方向に沿って変化すればよく、長尺方向における開口部３４２の中央及び両端のうちのどちらか一方から他方に向けて大きくならなくてもよい。 Also, the width in the crossing direction of the branching portion 341a shown in FIGS. 16 to 18 increases from one of the center and both ends of the opening 342 in the longitudinal direction toward the other, but is not limited thereto. . For example, the width in the intersecting direction of the branching portion 341a only needs to change along the longitudinal direction, and does not have to increase from one of the center and both ends of the opening 342 in the longitudinal direction toward the other. .
　また、開口部３４２は、長尺方向に沿って４つ並んで設けられたが、これに限らない。例えば、開口部３４２は、長尺方向に沿って２つ、３つ又は５つ以上並んで設けられてもよい。 Moreover, although the four openings 342 are provided side by side along the longitudinal direction, the present invention is not limited to this. For example, two, three, or five or more openings 342 may be provided along the longitudinal direction.
　［４－２．効果等］
　バスバー電極３４０は、開口部３４２を複数有し、開口部３４２は、長尺方向に沿って並んで設けられる。 [4-2. Effect]
The bus bar electrode 340 has a plurality of openings 342, and the openings 342 are provided along the longitudinal direction.
　これにより、バスバー電極３４０は、例えば、図１６～１８に示される第１の領域及び第２の領域のように、それぞれの領域に対する電荷伝達部３４１の面積占有率が異なる領域を有する。つまり、電荷伝達部３４１の面積占有率は、長尺方向に沿って不均一になる。言い換えると、バスバー電極３４０は、タブ配線２０と電荷伝達部３４１との接着強度が低い領域（第２の領域）と高い領域（第１の領域）とを有する。従来の太陽電池モジュールでは、タブ配線とバスバー電極とが接続しない部分が一様に設けられており、電気的ロスが一様に発生していた。一方、実施の形態４に係る太陽電池モジュールでは、タブ配線２０とバスバー電極３４０とが接続しない部分が不均一に設けられるため、電気的ロスを小さくしている。つまり、実施の形態４に係る太陽電池モジュールでは、タブ配線２０とバスバー電極３４０とが接続しない部分を場所によって小さくしているため、電気的ロスを小さくしている。したがって、温度サイクル等によりセル割れなどの不具合が発生するような状況になるまでは電気的ロスは抑制され、太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部３４１との接着強度が低い領域のタブ配線２０が剥がれる。これにより、タブ配線２０のバスバー電極３４０との接合が剥がれた領域にストレスを吸収させることができるため、以降は、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。また、タブ配線２０と電荷伝達部３４１との接着強度が高い領域では、タブ配線２０と電荷伝達部３４１とが接合しているため、集電効率の低下を抑制することができる。つまり、商品寿命内でのトータルの出力を高めた上で、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Thereby, the bus bar electrode 340 includes regions having different area occupancy rates of the charge transfer portions 341 for the respective regions, such as the first region and the second region shown in FIGS. That is, the area occupation ratio of the charge transfer portion 341 becomes non-uniform along the long direction. In other words, the bus bar electrode 340 has a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 341 is low (second region) and a region where the adhesive strength is high (first region). In the conventional solar cell module, the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly. On the other hand, in the solar cell module according to Embodiment 4, since the portion where the tab wiring 20 and the bus bar electrode 340 are not connected is provided unevenly, the electrical loss is reduced. That is, in the solar cell module according to Embodiment 4, since the portion where the tab wiring 20 and the bus bar electrode 340 are not connected is reduced depending on the location, the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 341 is low is peeled off. Thereby, stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 340 is peeled off, and thereafter, the stress of the solar cell element 11 and the tab wiring 20 can be reduced. Further, in the region where the adhesive strength between the tab wiring 20 and the charge transfer portion 341 is high, the tab wiring 20 and the charge transfer portion 341 are joined, so that a reduction in current collection efficiency can be suppressed. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
　また、バスバー電極３４０は、開口部３４２においてタブ配線２０と接合していない。したがって、温度サイクル等により太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０のバスバー電極３４０と接合していない領域にストレスを吸収させることができるので、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 Further, the bus bar electrode 340 is not joined to the tab wiring 20 in the opening 342. Therefore, even if stress is generated in the solar cell element 11 and the tab wiring 20 due to a temperature cycle or the like, the stress can be absorbed in a region that is not joined to the bus bar electrode 340 of the tab wiring 20. The stress on the tab wiring 20 can be reduced.
　分岐部３４１ａの交差方向の幅は、長尺方向における開口部３４２の中央及び両端のうちのどちらか一方から他方に向けて大きくなる。 The width in the crossing direction of the branching portion 341a increases from one of the center and both ends of the opening 342 in the longitudinal direction toward the other.
　これにより、開口部３４２毎に、長尺方向における開口部３４２の中央及び両端のうちのどちらか一方側をタブ配線２０とバスバー電極３４０との接着強度が低い領域にすることができる。 Thus, for each opening 342, either the center or both ends of the opening 342 in the longitudinal direction can be set to a region where the adhesive strength between the tab wiring 20 and the bus bar electrode 340 is low.
　また、タブ配線２０とバスバー電極３４０とが剥がれている領域において、バスバー電極３４０が有する抵抗成分による電力の損失を抑制することができる。 Further, in the region where the tab wiring 20 and the bus bar electrode 340 are peeled off, power loss due to the resistance component of the bus bar electrode 340 can be suppressed.
　（その他の実施の形態）
　以上、本発明に係る太陽電池モジュールについて、上記実施の形態に基づいて説明したが、本発明は、上記の実施に限定されるものではない。 (Other embodiments)
As mentioned above, although the solar cell module which concerns on this invention was demonstrated based on the said embodiment, this invention is not limited to said implementation.
　例えば、上記実施の形態では、フィンガー電極５０は、バスバー電極を貫通するように設けられなかったが、これに限らない。例えば、以下で説明する図１９～２１に示されるフィンガー電極３５０のようにバスバー電極４４０を貫通してもよい。 For example, in the above embodiment, the finger electrode 50 is not provided so as to penetrate the bus bar electrode, but is not limited thereto. For example, the bus bar electrode 440 may be penetrated like a finger electrode 350 shown in FIGS. 19 to 21 described below.
　図１９～２１は、その他の実施の形態に係るバスバー電極４４０の構成の一例を示す平面図である。 19 to 21 are plan views showing an example of the configuration of the bus bar electrode 440 according to another embodiment.
　図１９には、フィンガー電極４５０が図１３に示されるバスバー電極２４０ａを交差方向に貫通した構成を有するバスバー電極４４０が示される。これにより、フィンガー電極４５０は開口部４４２を交差方向に縦断する。 FIG. 19 shows a bus bar electrode 440 having a configuration in which the finger electrode 450 penetrates the bus bar electrode 240a shown in FIG. 13 in the crossing direction. Thereby, the finger electrode 450 cuts the opening 442 vertically in the crossing direction.
　同様に、図２０には、フィンガー電極４５０が図１４に示されるバスバー電極２４０ａを交差方向に貫通した構成を有するバスバー電極４４０が示される。これにより、フィンガー電極４５０は開口部４４２を交差方向に縦断する。 Similarly, FIG. 20 shows a bus bar electrode 440 having a configuration in which the finger electrode 450 penetrates the bus bar electrode 240a shown in FIG. 14 in the crossing direction. Thereby, the finger electrode 450 cuts the opening 442 vertically in the crossing direction.
　同様に、図２１には、フィンガー電極４５０が図１７に示されるバスバー電極３４０を交差方向に貫通した構成を有するバスバー電極４４０が示される。これにより、フィンガー電極４５０は開口部４４２を交差方向に縦断する。 Similarly, FIG. 21 shows a bus bar electrode 440 having a configuration in which the finger electrode 450 penetrates the bus bar electrode 340 shown in FIG. 17 in the crossing direction. Thereby, the finger electrode 450 cuts the opening 442 vertically in the crossing direction.
　これにより、図１３、１４及び１７では、フィンガー電極５０に直接接続されていない分岐部２４１ａ、３４１ａがあったが、図１９～２１では、すべての分岐部４４１ａがフィンガー電極４５０に直接接続される。したがって、タブ配線２０とバスバー電極４４０とが剥がれている領域において、抵抗成分による電力の損失を考慮した複数の分岐部４４１ａに受光電荷が分散されるため、バスバー電極４４０が有する抵抗成分による電力の損失をより抑制することができる。また、電荷伝達部４４１の面積占有率が長尺方向に沿って不均一になっている。言い換えると、バスバー電極４４０は、タブ配線２０と電荷伝達部４４１との接着強度が低い領域と高い領域とを有する。従来の太陽電池モジュールでは、タブ配線とバスバー電極とが接続しない部分が一様に設けられており、電気的ロスが一様に発生していた。一方、その他の実施の形態に係る太陽電池モジュールでは、タブ配線２０とバスバー電極４４０とが接続しない部分が不均一に設けられるため、電気的ロスを小さくしている。つまり、その他の実施の形態に係る太陽電池モジュールでは、タブ配線２０とバスバー電極４４０とが接続しない部分を場所によって小さくしているため、電気的ロスを小さくしている。したがって、温度サイクル等によりセル割れなどの不具合が発生するような状況になるまでは電気的ロスは抑制され、太陽電池素子１１及びタブ配線２０にストレスが生じたとしても、タブ配線２０と電荷伝達部４４１との接着強度が低い領域のタブ配線２０が剥がれる。これにより、タブ配線２０のバスバー電極４４０との接合が剥がれた領域にストレスを吸収させることができるため、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。つまり、商品寿命内でのトータルの出力を高めた上で、太陽電池素子１１及びタブ配線２０のストレスを低減することができる。 13, 14 and 17, there are branch portions 241 a and 341 a that are not directly connected to the finger electrode 50, but in FIGS. 19 to 21, all the branch portions 441 a are directly connected to the finger electrode 450. . Therefore, in the region where the tab wiring 20 and the bus bar electrode 440 are peeled off, the received charge is distributed to the plurality of branch portions 441a in consideration of the power loss due to the resistance component. Loss can be further suppressed. Further, the area occupation ratio of the charge transfer portion 441 is non-uniform along the longitudinal direction. In other words, the bus bar electrode 440 has a region where the adhesive strength between the tab wiring 20 and the charge transfer portion 441 is low and a region where the adhesive strength is high. In the conventional solar cell module, the portion where the tab wiring and the bus bar electrode are not connected is provided uniformly, and the electrical loss occurs uniformly. On the other hand, in the solar cell modules according to other embodiments, since the portion where the tab wiring 20 and the bus bar electrode 440 are not connected is provided unevenly, the electrical loss is reduced. That is, in the solar cell module according to the other embodiment, the portion where the tab wiring 20 and the bus bar electrode 440 are not connected is reduced depending on the location, so that the electrical loss is reduced. Therefore, the electrical loss is suppressed until a situation such as a cell crack occurs due to a temperature cycle or the like, and even if stress is generated in the solar cell element 11 and the tab wiring 20, the tab wiring 20 and the charge transfer The tab wiring 20 in the region where the adhesive strength with the portion 441 is low is peeled off. Thereby, since stress can be absorbed in the region where the bonding of the tab wiring 20 to the bus bar electrode 440 is peeled off, the stress of the solar cell element 11 and the tab wiring 20 can be reduced. That is, the stress of the solar cell element 11 and the tab wiring 20 can be reduced while increasing the total output within the product life.
　また、上記実施の形態では、例えば図１４に示されるバスバー電極２４０ａの交差方向の幅は、長尺方向に沿って変化したが、これに限らず、その他のバスバー電極の交差方向の幅も長尺方向に沿って変化してもよい。 In the above embodiment, for example, the width in the cross direction of the bus bar electrode 240a shown in FIG. 14 changes along the longitudinal direction. However, the width in the cross direction of other bus bar electrodes is not limited to this. It may change along the scale direction.
　また、上記実施の形態では、フィンガー電極５０は、直線であったが直線でなくてもよく、曲線であってもよい。 In the above embodiment, the finger electrode 50 is a straight line, but may not be a straight line, but may be a curved line.
　また、上記実施の形態では、太陽電池モジュールの構成は、複数の太陽電池素子１１が面上に行列状配置された構成を示したが、行列状配置に限らない。例えば、太陽電池モジュールの構成は、円環状配置や１次元の直線状又は曲線状に配置された構成であってもよい。 In the above embodiment, the configuration of the solar cell module is a configuration in which a plurality of solar cell elements 11 are arranged in a matrix on the surface, but is not limited to the matrix configuration. For example, the configuration of the solar cell module may be an annular arrangement or a one-dimensional linear or curved arrangement.
　その他、上記実施の形態に対して当業者が思いつく各種変形を施して得られる形態や、本発明の趣旨を逸脱しない範囲で上記実施の形態における構成要素及び機能を任意に組み合わせることで実現される形態も本発明に含まれる。 In addition, the present invention can be realized by any combination of the components and functions in the above-described embodiment without departing from the gist of the present invention, and forms obtained by making various modifications conceived by those skilled in the art. Forms are also included in the present invention.
　１　　太陽電池モジュール
　１１　　太陽電池素子
　２０　　タブ配線
　４０、１４０、２４０、２４０ａ、３４０、４４０　　バスバー電極
　４１、１４１、１４１ａ、１４１ｂ、２４１、３４１、４４１　　電荷伝達部
　４２、１４２、２４２、３４２、４４２　　開口部
　２４１ａ、３４１ａ、４４１ａ　　分岐部 DESCRIPTION OF SYMBOLS 1 Solar cell module 11 Solar cell element 20 Tab wiring 40,140,240,240a, 340,440 Bus-bar electrode 41,141,141a, 141b, 241,341,441 Charge transfer part 42,142,242,342,442 Opening Section 241a, 341a, 441a Branching section

Claims (13)

  1. 　隣り合う２つの太陽電池素子と、
    　前記２つの太陽電池素子を電気的に接続する長尺状のタブ配線と、を備え、
    　前記２つの太陽電池素子のそれぞれは、
    　前記タブ配線の長尺方向に沿って形成され、前記タブ配線と重なって接合する長尺状のバスバー電極を有し、
    　前記バスバー電極は、前記太陽電池素子で生成された受光電荷を前記タブ配線に伝達する電荷伝達部と、複数の開口部とを有し、
    　前記複数の開口部は、前記長尺方向に沿って並んで設けられ、
    　前記複数の開口部には、平面視における面積が異なる開口部が含まれる
    　太陽電池モジュール。     Two adjacent solar cell elements;
    A long tab wiring for electrically connecting the two solar cell elements,
    Each of the two solar cell elements is
    It has a long bus bar electrode that is formed along the lengthwise direction of the tab wiring and overlaps and joins the tab wiring,
    The bus bar electrode includes a charge transfer portion that transmits the received light charges generated by the solar cell element to the tab wiring, and a plurality of openings.
    The plurality of openings are provided side by side along the longitudinal direction,
    The plurality of openings include openings having different areas in plan view.
  2. 　前記複数の開口部のうちの面積の異なる開口部の前記長尺方向の幅及び当該長尺方向と平面視において交差する交差方向の幅の少なくとも一方は、異なる
    　請求項１に記載の太陽電池モジュール。     2. The solar cell module according to claim 1, wherein at least one of a width in the longitudinal direction of an opening having a different area among the plurality of openings and a width in an intersecting direction intersecting the longitudinal direction in plan view are different. .
  3. 　前記複数の開口部の平面視における面積は、前記長尺方向における前記バスバー電極の中央及び両端のうちのどちらか一方に近いほど大きい
    　請求項１又は２に記載の太陽電池モジュール。     The solar cell module according to claim 1 or 2, wherein an area of the plurality of openings in plan view is larger as it is closer to either the center or both ends of the bus bar electrode in the longitudinal direction.
  4. 　隣り合う２つの太陽電池素子と、
    　前記２つの太陽電池素子を電気的に接続する長尺状のタブ配線と、を備え、
    　前記２つの太陽電池素子のそれぞれは、
    　前記タブ配線の長尺方向に沿って形成され、前記タブ配線と重なって接合する長尺状のバスバー電極を有し、
    　前記バスバー電極は、前記太陽電池素子で生成された受光電荷を前記タブ配線に伝達する電荷伝達部と、複数の開口部とを有し、
    　前記複数の開口部は、前記長尺方向及び当該長尺方向と平面視において交差する交差方向に沿って並んで設けられ、
    　前記複数の開口部の前記交差方向に沿って並んで設けられる数は、前記長尺方向に沿って異なる
    　太陽電池モジュール。     Two adjacent solar cell elements;
    A long tab wiring for electrically connecting the two solar cell elements,
    Each of the two solar cell elements is
    It has a long bus bar electrode that is formed along the lengthwise direction of the tab wiring and overlaps and joins the tab wiring,
    The bus bar electrode includes a charge transfer portion that transmits the received light charges generated by the solar cell element to the tab wiring, and a plurality of openings.
    The plurality of openings are provided side by side along the cross direction intersecting the long direction and the long direction in plan view,
    The number of the plurality of openings provided side by side along the intersecting direction is different along the longitudinal direction.
  5. 　前記複数の開口部が前記交差方向に沿って並んで設けられる数は、前記長尺方向における前記バスバー電極の中央及び両端のうちのどちらか一方に近いほど多い
    　請求項４に記載の太陽電池モジュール。     The solar cell module according to claim 4, wherein the number of the plurality of openings provided side by side along the intersecting direction increases as the distance from the center and both ends of the bus bar electrode in the longitudinal direction increases. .
  6. 　前記複数の開口部の平面視における面積は、前記長尺方向における前記バスバー電極の中央及び両端のうちのどちらか一方に近いほど大きい
    　請求項４又は５に記載の太陽電池モジュール。     6. The solar cell module according to claim 4, wherein an area of the plurality of openings in plan view is larger as closer to one of the center and both ends of the bus bar electrode in the longitudinal direction.
  7. 　前記交差方向に沿って隣り合う２つの開口部の間隔は、当該交差方向における前記バスバー電極の中央に近いほど大きい
    　請求項４～６のいずれか１項に記載の太陽電池モジュール。     The solar cell module according to any one of claims 4 to 6, wherein an interval between two openings adjacent to each other in the intersecting direction is larger as it is closer to the center of the bus bar electrode in the intersecting direction.
  8. 　隣り合う２つの太陽電池素子と、
    　前記２つの太陽電池素子を電気的に接続する長尺状のタブ配線と、を備え、
    　前記２つの太陽電池素子のそれぞれは、
    　前記タブ配線の長尺方向に沿って形成され、前記タブ配線と重なって接合する長尺状のバスバー電極を有し、
    　前記バスバー電極は、前記太陽電池素子で生成された受光電荷を前記タブ配線に伝達する電荷伝達部と、前記長尺方向と平面視において交差する交差方向に沿って並ぶ複数の分岐部に当該電荷伝達部を分岐させる開口部とを有し、
    　前記分岐部の前記交差方向の幅は、前記長尺方向に沿って変化する
    　太陽電池モジュール。     Two adjacent solar cell elements;
    A long tab wiring for electrically connecting the two solar cell elements,
    Each of the two solar cell elements is
    It has a long bus bar electrode that is formed along the lengthwise direction of the tab wiring and overlaps and joins the tab wiring,
    The bus bar electrode includes a charge transfer portion that transmits the received light charges generated by the solar cell element to the tab wiring, and a plurality of branch portions that are aligned along a crossing direction that intersects the longitudinal direction in plan view. An opening for branching the transmission part,
    The width | variety of the said crossing direction of the said branch part changes along the said elongate direction.
  9. 　前記開口部は、前記長尺方向における前記バスバー電極の両端のうちの少なくとも一端に設けられた切り欠きである
    　請求項８に記載の太陽電池モジュール。     The solar cell module according to claim 8, wherein the opening is a notch provided at at least one end of both ends of the bus bar electrode in the longitudinal direction.
  10. 　前記分岐部の前記交差方向の幅は、前記長尺方向における前記バスバー電極の中央及び両端のうちのどちらか一方から他方に向けて大きくなる
    　請求項８又は９に記載の太陽電池モジュール。     10. The solar cell module according to claim 8, wherein a width of the branch portion in the intersecting direction increases from one of the center and both ends of the bus bar electrode in the longitudinal direction toward the other.
  11. 　前記バスバー電極は、前記開口部を複数有し、
    　前記開口部は、前記長尺方向に沿って並んで設けられる
    　請求項８に記載の太陽電池モジュール。     The bus bar electrode has a plurality of the openings,
    The solar cell module according to claim 8, wherein the opening is provided side by side along the longitudinal direction.
  12. 　前記分岐部の前記交差方向の幅は、前記長尺方向における前記開口部の中央及び両端のうちのどちらか一方から他方に向けて大きくなる
    　請求項１１に記載の太陽電池モジュール。     The solar cell module according to claim 11, wherein a width of the branching portion in the intersecting direction increases from one of the center and both ends of the opening in the longitudinal direction toward the other.
  13. 　前記バスバー電極の前記長尺方向と平面視において交差する交差方向の幅は、前記長尺方向に沿って変化する
    　請求項１～１２のいずれか１項に記載の太陽電池モジュール。     The solar cell module according to any one of claims 1 to 12, wherein a width of a crossing direction of the bus bar electrode that intersects the long direction in a plan view changes along the long direction.
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