WO2005098969A1 - Solar battery and solar battery module - Google Patents

Solar battery and solar battery module Download PDF

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Publication number
WO2005098969A1
WO2005098969A1 PCT/JP2005/005910 JP2005005910W WO2005098969A1 WO 2005098969 A1 WO2005098969 A1 WO 2005098969A1 JP 2005005910 W JP2005005910 W JP 2005005910W WO 2005098969 A1 WO2005098969 A1 WO 2005098969A1
Authority
WO
WIPO (PCT)
Prior art keywords
interconnector
solar cell
current collecting
solar
cell module
Prior art date
Application number
PCT/JP2005/005910
Other languages
French (fr)
Japanese (ja)
Inventor
Akihide Takaki
Satoshi Tanaka
Original Assignee
Sharp Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2004114684A external-priority patent/JP2005302902A/en
Priority claimed from JP2004261194A external-priority patent/JP2006080217A/en
Application filed by Sharp Kabushiki Kaisha filed Critical Sharp Kabushiki Kaisha
Publication of WO2005098969A1 publication Critical patent/WO2005098969A1/en

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Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00Semiconductor 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
    • H01L31/04Semiconductor 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
    • H01L31/042PV modules or arrays of single PV cells
    • H01L31/05Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/50Photovoltaic [PV] energy

Definitions

  • the present invention relates to a solar cell and a solar cell module, and more particularly, to a solar cell in which an interconnector is connected to a current collecting electrode provided on the surface of the solar cell, and a plurality of solar cells by the interconnector
  • the present invention relates to a solar cell module to which is connected.
  • a solar cell module is formed by connecting a plurality of solar cells.
  • a conventional solar cell used in this solar cell module is composed of a semiconductor substrate 11 and current collecting electrodes 15 and 16 provided on the front and back thereof.
  • An N-type region 12 and a P-type region 13 are formed on a semiconductor substrate 11 used for a solar cell 20, and a semiconductor junction 14 is formed at an interface between the N-type region 12 and the P-type region 13. .
  • a current collecting electrode 15 on the front surface is provided, and on the surface of the P-type region 13, a current collecting electrode 16 on the back surface is provided.
  • the current collecting electrode 15 on the front surface is composed of a grid-shaped finger portion 15 b and a bus bar portion 15 a connecting the interconnector 17.
  • the current collecting electrode 16 on the back surface is composed of a silver electrode (not shown) for connecting the interconnector 7 and an aluminum current collecting electrode (not shown) formed on almost the entire back surface excluding the silver electrode. It is composed of
  • an interconnector 17 as shown in FIGS. 13 and 14 is used to connect a plurality of solar cells 20.
  • the interconnector 17 has electrode contact portions 17a and 17b at both ends, and is made of rectangular copper foil or invar (an alloy of iron and nickel) or the like, and its entire surface is covered with solder.
  • a plurality of solar cells 20 are connected as shown in FIG. That is, one of the electrode contact portions 17a is disposed over substantially the entire length of the current collecting electrode 15 on the surface of the solar cell 20 on the bus bar portion 15a, and a plurality of portions are joined to the bus bar portion 15a. Connected to the nose bar 15a of the current collecting electrode 15 on the front side.
  • the other electrode contact portion 17b is connected to the current collecting electrode 16 on the back by soldering! RU
  • one of the electrode contacts 17a of the interconnector 17 connected to the bus bar 15a of the current collecting electrode 15 on the surface of the solar battery cell 20 is referred to in this specification.
  • Various types of such solar cell modules have been proposed (for example, see Patent Document 1).
  • the solar cell device described in Patent Document 1 uses a stranded wire as an interconnector
  • Patent Document 1 Japanese Patent Application Laid-Open No. H11 251613
  • soldering is used to connect the electrode contact portion of the interconnector to the current collecting electrode of the solar cell.
  • the heat of the soldering raises the temperature of the electrode contact portion of the interconnector and the current collecting electrode of the solar cell, and when the raised temperature returns to normal temperature, the solar cell is formed. It is a well-known fact that a compressive stress is applied to a given semiconductor substrate.
  • the only way to increase the cross-sectional area of the interconnector is to increase the thickness of the interconnector.
  • the above-mentioned compressive stress applied to the semiconductor substrate increases due to the following two factors.
  • the welding between the current collecting electrode on the surface and the interconnector takes a long time, so that the interconnector expands due to thermal expansion, and the compressive stress applied to the semiconductor substrate increases.
  • the above-described compressive stress increases, so that a large warpage occurs in the semiconductor substrate, which causes a problem such as cell cracking and electrode peeling, thereby lowering the manufacturing yield. .
  • the solar cell device described in Patent Document 1 uses a stranded wire as the interconnector.
  • the use of a stranded wire as an interconnector is one solution to the problem described above. Even if a power stranded wire is used, it is still a single linear wire as a whole. I have to say that it stays at a level. In other words, since there is no gap between the current collecting electrode and the interconnector, for example, if an interconnector using a stranded wire whose entire surface is covered with solder is used, the entire surface is covered with a solder.
  • the stranded wire that has expanded due to the heat of hot air reflow, a soldering iron, etc. is fixed to the current collecting electrode on the surface in the expanded state. Then, when the temperature increased by heating decreases and the stranded wire shrinks, the stranded wire that should have the effect of reducing the warpage of the semiconductor substrate due to the elongation of the stranded wire by unwinding the stranded wire, It is fixed and cannot be undone. Therefore, when a stranded wire is used as the interconnector, the effect of reducing the warpage of the semiconductor substrate is drastically reduced, and eventually, when the stranded wire shrinks, the semiconductor substrate is warped.
  • the stranded wire before the stranded wire exhibits the effect of reducing the warpage of the semiconductor substrate, the stranded wire is fixed to the current collecting electrode on the surface of the solar cell by the solder. It is almost gone. Therefore, if you try to use a stranded wire for the interconnector, Therefore, an interconnector having a special structure in which solder is coated only on the portion that comes into contact with the solder must be used, and an extra process is required for the manufacture of the interconnector, and the cost increases. In addition, the process of processing the stranded wire into the interconnector itself is complicated and time-consuming.
  • the present invention has been made to solve the above problems, and even if the thickness of the interconnector is increased to reduce the resistance loss with the increase in the area of the solar cell, In the manufacturing process of the solar cell module, it is possible to prevent the semiconductor substrate of the solar cell from being greatly warped, cracking the cell, peeling off the electrodes, etc., thereby preventing a reduction in manufacturing yield and reducing a resistance loss.
  • FF fill factor: photoelectric conversion efficiency
  • a solar cell of the present invention made to solve the above problem has a solar cell on which a current collecting electrode is formed, and an interconnector is connected to the current collecting electrode of the solar cell.
  • the interconnector is formed with an uneven portion.
  • the solar cell module of the present invention is a solar cell module in which a plurality of solar cells are arranged and connected by the solar cell power S interconnectors adjacent to each other. It is characterized in that the interconnector has an uneven portion.
  • the above-mentioned solar cell or solar cell module is configured such that at least a part of a portion of the interconnector used for the solar cell or the solar cell, which is located on a front surface or a back surface of the solar cell, is formed in a concave-convex shape. I prefer to.
  • the interconnector used for the above-mentioned solar cell module may include a part of a part located on the front surface of the solar cell and a part of a part located on the back surface of the solar cell. Only the part may be formed in an uneven shape. [0015] In the above-described solar cell or solar cell module, since the uneven portion is formed in the interconnector, expansion and contraction of the uneven portion of the interconnector during heating and cooling in the manufacturing process of the solar cell module causes It is unlikely to occur in the direction parallel to the surface of the photovoltaic cells as soon as it occurs along the uneven direction.
  • the cross-sectional area of the interconnector is increased, so that the compressive stress is increased in accordance with the thickness, or As the thickness of the interconnect becomes thicker, even though the welding of the surface electrode and the interconnector takes a long time and the expansion of the interconnector becomes large due to thermal expansion, the interconnector may be in contact with the surface of the solar cell. Expansion and contraction in the parallel direction can be suppressed. Therefore, it is possible to prevent the semiconductor substrate of the solar battery cell from being greatly warped, or the cell from being cracked or the electrode from being peeled off during the manufacturing process of the solar battery module.
  • the uneven portion formed on the interconnector causes a partial gap between the current collecting electrode on the surface and the interconnector, even if the interconnector is entirely covered with solder, The effect of reducing the warpage of the semiconductor substrate can be sufficiently obtained. Therefore, a decrease in manufacturing yield can be prevented, and the thickness of the interconnect can be increased, so that the resistance loss of the solar cell module can be reduced and the FF can be increased.
  • the unevenness formed on the interconnector of the solar cell or the solar cell module may be a corrugated shape or an arched or anti-arched shape. Is also good.
  • the shape of these concavities and convexities should be a partial projection type or a partial depression type.
  • the pitch of the irregularities formed on the interconnector of the solar cell or the solar cell module is less than the length of one side of the solar cell and the height of the irregularities is 2 mm or less. preferable.
  • a flat portion may be formed in the interconnector, and the uneven portion and the flat portion may be alternately formed a plurality of times.
  • the plurality of concave and convex portions are formed in the interconnector. For this reason, processing during the manufacturing process of the solar cell module is performed. At the time of thermal cooling, the expansion and contraction force due to the heat of the concave and convex portions is generated along the concave and convex direction, and is hardly generated in the direction parallel to the surface of the solar cell.
  • the thickness of the interconnector is increased in order to reduce the resistance loss, even if the compressive stress increases according to the thickness due to the increase in the cross-sectional area of the interconnector, Even if the expansion of the interconnector increases due to thermal expansion due to the time required for welding to the interconnector, expansion and contraction of the interconnector in a direction parallel to the surface of the solar cell can be suppressed. Therefore, in the manufacturing process of the solar cell module, it is possible to prevent the semiconductor substrate of the solar cell from being significantly warped, or the cells from being cracked or the electrodes from being peeled off. Therefore, a decrease in manufacturing yield can be prevented, and the thickness of the interconnector can be increased, so that the resistance loss of the solar cell module can be reduced and the FF can be increased.
  • the flat portion is formed by inserting the flat portion between the concavo-convex portions adjacent to the interconnector, the flat portion is formed on the upper surface of the current collecting electrode.
  • the interconnector By bonding to the current collector, the interconnector can be pressed and fixed to the current collecting electrode, and the interconnector plays a role of reinforcing the strength of the current collecting electrode. Can be enhanced.
  • the presence of the flat portion in the interconnector allows the interconnector to be vacuum-adsorbed and transported, thereby improving the productivity of the solar cell module.
  • the above-mentioned uneven portion of the interconnector is formed by independently forming a protrusion-shaped portion having a single rounded top.
  • a plurality of protrusion-shaped portions each having a single rounded top are formed, and the plurality of protrusion-shaped portions are formed by inserting a linear shape portion between adjacent ones of the protrusion-shaped portions. U, like to do.
  • the linear part is formed on the upper surface of the current collecting electrode.
  • the interconnector can be firmly fixed to the current collecting electrode similarly to the flat portion, and the interconnector reinforces the strength of the current collecting electrode. Therefore, the strength of the current collecting electrode can be further enhanced.
  • the projection-shaped portion is formed so that the top of the projection-shaped portion is rounded, when the interconnector is molded using a hydraulic press, the molded interconnector is formed. It is possible to suppress a decrease in the productivity of the solar cell or the solar cell module, which is prevented from being wound by a hooking force on a mold.
  • the linear portion of the uneven portion of the interconnector is longer than the width of the bottom of the projecting portion of the uneven portion, and Preferably, it is formed to be shorter than the length of the.
  • the interconnector is fixedly fixed to the current collecting electrode while maintaining the effect of reducing the warpage of the semiconductor substrate due to the projection-shaped portion of the uneven portion. And the strength of the current collecting electrode can be enhanced.
  • the protrusion-shaped portion of the uneven portion of the interconnector has a width at the bottom of the protrusion-shaped portion approximately four times the height of the protrusion-shaped portion. It is preferred to be formed so that.
  • expansion and contraction of the protrusion-shaped portion of the uneven portion can be effectively caused along the protrusion direction during heating and cooling in the manufacturing process of the solar cell module.
  • expansion and contraction of the interconnector in a direction parallel to the surface of the solar cell can be effectively suppressed. Therefore, the above-described warpage of the semiconductor substrate can be effectively reduced.
  • the interconnector is formed such that portions of the solar cell that adhere to the upper surfaces of both ends of the current collecting electrode are flat. . By doing so, the interconnector can be firmly fixed to the front surface or the back surface of the solar cell using the flat portion.
  • the solar cell module and the interconnector can be configured such that the solar cell module is sandwiched between a transparent substrate and a back cover. By doing so, the front and back surfaces of the solar cell can be protected.
  • a part of the interconnector of the solar cell module may be formed in a linear shape.
  • a stress release that relieves various stresses on the interconnector is formed in a portion of the interconnector between adjacent solar cells connected by the interconnector.
  • the stress release is a crank-shaped component formed in the interconnector in advance, and has a function of alleviating various stresses applied to the interconnector.
  • the stress release is formed in the direction in which the solar cells are arranged in a length of about the thickness of the solar cells.
  • the stress release force is formed at a portion between the solar cells of the interconnector, so that a plurality of the solar cells are arranged or a plurality of the arranged solar cells are transparent.
  • the stress generated in the interconnector can be released by the interconnector pressing down the edge of the solar cell.
  • cell cracking and force of four which are generated when the interconnector presses the edge of the solar cell, can be significantly reduced.
  • expansion or contraction occurs due to heating, cooling, or the like, the change in length due to the expansion or contraction can be released in a direction having little effect, and the interconnector expands and contracts in the arrangement direction of the solar cells. Can be suppressed.
  • the semiconductor substrate of the solar cell in the manufacturing process of the solar cell module, it is possible to prevent the semiconductor substrate of the solar cell from being significantly warped, or the cells from being cracked or the electrodes from being peeled off.
  • a further advantage of the stress release is that after the solar cell module is completed, the interconnector thermally expands due to direct sunlight or the like, or the transparent substrate on the front surface of the solar cell and the back cover can be used. Even if the transparent filler material expands and contracts during this time, it is possible to suppress expansion and contraction of the interconnector in the arrangement direction of the solar cells. Therefore, the reliability of the solar cell module can be improved, and the life can be prolonged.
  • the interconnector has a flat edge portion of the solar cell, and irregularities are formed on a front side and a rear side of the interconnector except for the flat portion. It may be configured as follows. Doing something like this Thereby, the interconnector can be firmly fixed to the front and back surfaces of the solar cell using the flat edge portion.
  • the solar cell module of the present invention even if the thickness of the interconnector is increased to reduce the resistance loss with the increase in the area of the solar cell, the solar cell module can be used.
  • the manufacturing process it is possible to prevent the semiconductor substrate of the solar battery cell from being significantly warped, cell breakage, electrode peeling, and the like, thereby preventing a reduction in manufacturing yield and reducing resistance loss to reduce FF. Can be improved.
  • FIG. 1 is a plan view of a solar cell according to a first embodiment.
  • FIG. 2 is a sectional view taken along line AA of FIG. 1.
  • FIG. 3 is a cross-sectional view of the solar cell module according to the first embodiment.
  • FIG. 4 is an enlarged view of an inter-cell portion of an interconnector used in the solar cell module according to the first embodiment.
  • FIG. 5 is an explanatory diagram of a reflow method used for manufacturing the solar cell module according to the first embodiment.
  • 6 (a) to 6 (h) are explanatory diagrams showing other examples of the shape of the electrode contact portion of the interconnector.
  • FIG. 7 is a plan view of a solar cell according to a second embodiment.
  • FIG. 8 is a sectional view taken along the line A′-A ′ in FIG. 7.
  • FIG. 9 is a cross-sectional view of a solar cell module according to a second embodiment.
  • FIG. 10 is a partially enlarged view of FIG.
  • FIG. 11 is a diagram showing a shape of an uneven portion of the interconnector.
  • FIG. 12 is a view showing the shape of another example of the uneven portion of the interconnector.
  • FIG. 13 is a plan view of a conventional solar cell.
  • FIG. 14 is a cross-sectional view taken along line BB of FIG. 13.
  • FIG. 15 is a cross-sectional view of a conventional solar cell module.
  • FIG. 1 is a plan view of a solar cell according to the first embodiment
  • FIG. 2 is a cross-sectional view thereof
  • FIG. 3 is a cross-sectional view of a solar cell module according to the present embodiment.
  • the solar cell is configured by connecting one interconnector 7 to one solar cell 10.
  • the solar cell module is configured by connecting a plurality of arranged solar cells 10 in series using an interconnector 7. That is, the solar cell module includes, in the arrayed solar cells, the other end 7b of the interconnector 7 having one end 7a connected to the surface of one adjacent solar cell and the other end of the adjacent solar cell. It is configured by connecting to the back surface.
  • a solar cell 10 used in the solar cell and the solar cell module according to the present embodiment includes a semiconductor substrate 1 and a current collecting electrode 5 on the surface formed on the front and back surfaces thereof. And a current collecting electrode 6 on the back surface.
  • the semiconductor substrate 1 is formed of a P-type silicon substrate such as single-crystal silicon or polycrystalline silicon having a square shape with a side of about 155 mm and a thickness of about 0.2 to 0.3 mm.
  • a PZN junction is formed on the surface of the P-type silicon substrate. Specifically, the formation of the PZN junction is performed by applying a solution containing N-type impurities to the surface of the P-type silicon substrate. Alternatively, the PZN junction is formed by placing this P-type silicon substrate in the gas phase and thermally diffusing N-type impurities at a temperature of about 800 to 900 ° C to the surface of the P-type silicon substrate. This is performed by forming an impurity diffusion layer on the substrate.
  • the N-type diffusion surface thus formed is referred to as the front surface, which is the light receiving surface of the solar cell 10, and the non-diffusion surface is referred to as the back surface. That is, an N-type region 2 and a P-type region 3 are formed in the semiconductor substrate 1, and an interface between the N-type region 2 and the P-type region 3 is formed. A semiconductor junction 4 is formed at this time. It is desirable to form an antireflection film such as a metal oxide on the surface that is the light receiving surface.
  • the semiconductor substrate 1 may be formed of single crystal gallium arsenide or the like other than silicon.
  • a collecting electrode 5 on the front surface is formed on the surface of the N-type region 2, and a collecting electrode on the back surface is formed on the surface of the P-type region 3, as shown in FIGS. Electrode 6 is formed.
  • the collecting electrode 5 on the surface is composed of a grid-like finger portion 5b and a bus bar portion 5a for connecting the interconnector 7.
  • the current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface are specifically formed as follows. That is, in the electrode forming step, the light-receiving surface of the semiconductor substrate 1 is patterned in a grid shape with a metal or a substance similar thereto as the current collecting electrode 5, and the current is collected using a vacuum deposition method or a screen printing method. The electrode 5 is formed. A metal or a substance similar thereto is patterned as a current collecting electrode 6 on substantially the entire back surface, and the current collecting electrode 6 is formed using a vacuum deposition method or a screen printing method.
  • the current collecting electrode 5 on the front surface is composed of the bus bar portion 5a for connecting the interconnector 7, and the grid-like finger portion 5b branched and formed to cross the bus bar portion 5a.
  • the two busbar portions 5a are formed in parallel so as to cross substantially the entire surface of the semiconductor substrate 1.
  • a plurality of finger portions 5b are formed over substantially the entire length of the substrate 1 so as to intersect the bus bar portion 5a at right angles.
  • the width of the bus bar portion 5a is, for example, about 2 mm, and the width of the finger portion 5b is, for example, about 0.2 mm.
  • the current collecting electrode 5 on this surface is, for example, screen-printed with silver powder, glass frit, a binder, and a paste having a force such as a solvent and baked at a temperature of about 700 to 800 ° C. It is formed by coating.
  • the current collecting electrode 6 on the back surface is composed of a silver electrode (not shown) for connecting the interconnector 7, and a current collecting aluminum electrode (not shown) formed on almost the entire surface except the silver electrode.
  • the silver electrode is covered with a solder layer.
  • the interconnector 7 is connected to the solar cell 10 to form a solar cell as shown in FIGS. 1 and 2. Further, by arranging a plurality of solar cells and connecting them in series, a solar cell module as shown in FIG. 3 is formed. The interval between the solar cells 10 in the solar cell module is about 2 to 3 mm. As shown in FIG. 3, the interconnector 7 includes one electrode contact portion 7a and the other electrode contact portion 7b with the inter-cell portion 7c interposed therebetween. When the interconnector 7 is viewed from the side, the shape of the interconnector 7 is such that one electrode contact portion 7a is formed higher than the other electrode contact portion 7b and is formed in a step shape.
  • Each of the one electrode contact portion 7a and the other electrode contact portion 7b has a shape which is bent up and down in a wavy shape over the entirety. Also, two edge portions 7d, 7d of one electrode contact portion 7a of the interconnector 7 connected to the bus bar portion 5a of the current collecting electrode 5 on the front surface of the solar cell 10 and the back surface of the solar cell 10 The two edge portions 7e and 7e of the other electrode contact portion 7b of the interconnector 7 connected to the collecting electrode 6 have a flat shape. By doing so, it is possible to firmly adhere to the solar cell 10 while maintaining the effect of bending the electrode contact portions 7a and 7b of the interconnector 7 up and down.
  • the interconnector 7 is formed of a rectangular copper foil, invar, or the like.
  • a copper wire or an Invar wire having a width of 2 mm and a thickness of 0.15 to: L Omm is immersed in a solder bath having a desired composition, and wound at a constant speed. put out.
  • one electrode contact portion 7a and the other electrode contact portion 7b of the interconnector 7 are bent up and down in a wavy manner over the entire length thereof.
  • the pitch p of the wavy bent portion needs to be shorter than the length of the bus bar portion 5a, and is set to about 3.5 mm in the present embodiment.
  • the height q of the peak is set to about 0.4 mm in the present embodiment, which is desirably 2 mm or less from a practical point of view.
  • a stress release having a shape as shown in FIG. 4 is formed in the inter-cell portion 7c of the interconnector 7.
  • the stress release is a crank-shaped component formed in the interconnector 7 in advance, and has a function of relieving stresses such as various stresses applied to the interconnector 7 by escaping in a direction having less influence. .
  • This stress release is formed in the direction of arrangement of the solar cells 10 so as to have a length of about the thickness of the solar cells 10.
  • the drop height X is about lmm and the drop width y is about 0.5 mm in FIG. Since the interval between the solar cells 10 is about 2 to 3 mm, the drop height X and the drop width y are determined by the thickness of the solar cells 10 and the interconnect. The thickness of the cutter 7 can be sufficiently covered.
  • the height z of the play portions 7f and 7g which preferably include the play portions 7f and 7g before and after the stress release, is set to about 0.1 mm.
  • the above interconnector 7 is connected to solar cell 10 to form a solar cell. That is, as shown in FIGS. 1 and 2, the lower end of the valley portion of one of the corrugated electrode contact portions 7a of the interconnector 7 is brought into contact with the surface of the bus bar portion 5a of the solar cell 10a, The contact portion is spot-connected using solder or the like to form a solar cell.
  • a solar cell module is formed as shown in FIG. That is, first, a plurality of solar cells 10 with the interconnector 7 attached to the surface are arranged. Then, the other electrode contact portion 7b in the form of a corrugated shape covered with solder of the interconnector 7 in which the one electrode contact portion 7a is already bonded to the bus bar portion 5a of one of the adjacent solar cells 1 Oa The upper end of the crest portion is set so as to be in contact with the silver electrode covered with solder on the current collecting electrode 6 on the back surface of the other solar cell 10b adjacent to each other.
  • a method of connecting the interconnector 7 to the solar cell 10 in addition to the above-mentioned method, there is a reflow method, a method using a soldering iron, or the like.
  • the reflow method instead of blowing hot air when melting the solder, as shown in Fig. 5, the interconnector 7 and the solar cell 10 are sandwiched between the SUS plates 8 heated to a high temperature to melt the solder. Is the way.
  • a solar cell module it is necessary to protect the front and back surfaces of the solar cell 10. Therefore, as a solar cell module product, a plurality of solar cells 10 provided with the interconnector 7 described above are used.
  • the solar cell module is formed between the transparent substrate and the back cover.
  • the front surface which is the light receiving surface of the solar cell 10
  • a transparent plate such as a glass plate
  • a back cover with the transparent substrate facing the transparent substrate.
  • a super straight system in which a plurality of provided solar cells are sealed is generally used.
  • the transparent filler for example, PVB (polybutyrol), which has a small decrease in light transmittance, and EVA (ethylene buracetate) excellent in metahumidity are used.
  • one electrode contact portion 7a and the other electrode contact portion 7b of interconnector 7 are configured to bend up and down in a wave shape.
  • the expansion and contraction of each bent portion of the one electrode contact portion 7a or the other electrode contact portion 7b occurs along the bent direction and hardly occurs in the arrangement direction of the solar cells 10 . Therefore, as the thickness of the interconnector 7 is increased in order to reduce the resistance loss, the cross-sectional area of the interconnector 7 is increased, and the compressive stress applied to the semiconductor substrate 1 is increased in accordance with the thickness.
  • a stress release is formed in the inter-cell portion 7c of the interconnector 7, and play is provided before and after the stress release. Therefore, when arranging a plurality of solar cells or enclosing the arranged plurality of solar cells between a transparent substrate and a back cover with a transparent filler, the interconnector 7 is connected to the edge of the solar cell 10. By pressing down, the stress generated in the interconnector 7 can be released. For this reason, cell breaks, splinters, and the like that occur when the interconnector 7 presses the edge of the solar cell 10 can be significantly reduced.
  • the expansion of the interconnector 7 due to thermal expansion is large, in combination with the fact that the one electrode contact portion 7a and the other electrode contact portion 7b of the interconnector 7 are formed to bend up and down in a wave shape.
  • expansion and contraction of the interconnector 7 in the arrangement direction of the solar cells 10 can be suppressed. For this reason, it is possible to prevent the semiconductor substrate 1 of the solar cell 10 from being significantly warped, cracking the cell, peeling off the electrode, or the like during the manufacturing process of the solar cell module.
  • the interconnector 7 thermally expands due to direct sunlight or the like after completion of the solar cell module, or if the transparent filler material expands and contracts between the front transparent substrate and the back cover, The expansion and contraction of 7 in the arrangement direction of the solar cells 10 can be suppressed. Therefore, the reliability of the solar cell module can be improved and the life can be prolonged.
  • the vertical direction and the arrangement direction of the solar cells 10 due to the strain and the like generated during the manufacturing process and after the completion of the solar cell module. Even if the tension is applied to the solar battery cell 1, it can be absorbed or reduced, and the advantages of the stress release described above can be more effectively exerted.
  • the electrode contact portions 7a and 7b of the interconnector 7 are bent up and down to process the shapes of the electrode contact portions 7a and 7b.
  • the shape of the electrode contact portions 7a and 7b is not limited to this, and any shape may be adopted as long as the shape is uneven.
  • FIGS. 6A to 6H schematically show other examples of the shapes of the electrode contact portions 7a and 7b. It is. For example, as shown in FIG. 6 (a), semi-circles are continuously arranged in a row, and are arch-shaped, anti-arch shaped as shown in FIG. 6 (f), or partially projecting or You may use a partially concave shape!
  • the entirety of one electrode contact portion 7a and the other electrode contact portion 7b of the interconnect connector 7 is provided with an uneven portion.
  • only one electrode contact portion 7a or the other electrode contact portion 7b may be provided, or the one electrode contact portion 7a or the other electrode contact portion 7b, or an uneven portion may be provided only on a part of both.
  • the inter-cell portion 7c of the inter-connector 7 has a shape of the force inter-cell portion 7c forming a stress release.
  • the present invention is not limited to this, and may be, for example, a linear shape.
  • FIG. 7 is a plan view of the solar cell according to the present embodiment
  • FIG. 8 is a cross-sectional view taken along line A′-A ′ of FIG. 7
  • FIG. 3 is a cross-sectional view of the solar cell module according to the present embodiment. is there.
  • the solar cell is configured by connecting one interconnector 7 to one solar cell 10.
  • the solar cell module is configured by connecting a plurality of arranged solar cells 10 in series using an interconnector 7. That is, the solar cell module is configured by arranging a plurality of the above solar cells, and connecting the other end 7b of the interconnector 7 having one end 7a connected to the front surface of the solar cell to the back surface of the adjacent solar cell. Being done.
  • a solar cell 10 used in the solar cell and the solar cell module according to the present embodiment includes a semiconductor substrate 1, a current collecting electrode 5 formed on the front and back surfaces, and a back surface.
  • the current collecting electrode 6 is composed of:
  • the semiconductor substrate 1 is formed of a P-type silicon substrate such as single-crystal silicon or polycrystalline silicon having a square shape with a side of about 155 mm and a thickness of about 0.24 mm.
  • This P-type silicon A PZN junction is formed on the surface of the substrate. Specifically, the formation of the PZN junction is performed by applying a solution containing N-type impurities to the surface of the P-type silicon substrate. Alternatively, the PZN junction is formed by placing this P-type silicon substrate in the gas phase and thermally diffusing N-type impurities at a temperature of about 800 to 900 ° C to the surface of the P-type silicon substrate. This is performed by forming an impurity diffusion layer on the substrate.
  • the N-type diffusion surface thus formed is referred to as the front surface, which is the light receiving surface of the solar cell 10, and the non-diffusion surface is referred to as the back surface. That is, the N-type region 2 and the P-type region 3 are formed in the semiconductor substrate 1, and the semiconductor junction 4 is formed at the interface between the N-type region 2 and the P-type region 3. It is desirable to form an antireflection film such as a metal oxide on the surface that is the light receiving surface.
  • the semiconductor substrate 1 may be formed of single crystal gallium arsenide or the like other than silicon.
  • the current collecting electrode 5 on the front surface is formed on the surface of the N-type region 2, and the collecting electrode 5 on the rear surface is formed on the surface of the P-type region 3, as shown in FIGS. Electrode 6 is formed.
  • the collecting electrode 5 on the surface is composed of a grid-like finger portion 5b and a bus bar portion 5a for connecting the interconnector 7.
  • the current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface are specifically formed as follows. That is, in the electrode forming step, the light-receiving surface of the semiconductor substrate 1 is patterned in a grid shape with a metal or a substance similar thereto as the current collecting electrode 5, and the current is collected using a vacuum deposition method or a screen printing method. The electrode 5 is formed. A metal or a substance similar thereto is patterned as a current collecting electrode 6 on substantially the entire back surface, and the current collecting electrode 6 is formed using a vacuum deposition method or a screen printing method.
  • the current collecting electrode 5 on the front surface is composed of the bus bar portion 5a for connecting the interconnector 7, and the grid-like finger portion 5b branched and formed to cross the bus bar portion 5a.
  • the two busbar portions 5a are formed in parallel so as to cross substantially the entire surface of the semiconductor substrate 1.
  • a plurality of finger portions 5b are formed over substantially the entire length of the substrate 1 so as to intersect the bus bar portions 5a at right angles.
  • the width of the bus bar part 5a is, for example, about 2 mm, and the width of the finger part 5b is, for example, about 0.2 mm.
  • the current collecting electrode 5 on this surface is screen-printed, for example, with silver powder, glass frit, a binder, and a paste such as a solvent, and baked at a temperature of about 700 to 800 ° C. It is formed by coating with a solder layer.
  • the current collecting electrode 6 on the back surface includes a silver electrode (not shown) for connecting the interconnector 7 and a current collecting aluminum electrode (not shown) formed on almost the entire surface except the silver electrode.
  • the silver electrode is covered with a solder layer.
  • the interconnector 7 is connected to the solar cell 10 to form a solar cell as shown in FIGS. 7 and 8.
  • a solar cell module as shown in FIG. 9 is formed.
  • the interval between the solar cells 10 in the solar cell module is about 2 to 3 mm.
  • the interconnector 7 is formed of a copper wire or an invar wire having a width of 2 mm and a thickness of 0.3 mm. As shown in Figs. 8 and 9, the inter-cell portion 7c is interposed therebetween. It is composed of one electrode contact 7a and the other electrode contact 7b. One electrode contact portion 7a is connected to the bus bar portion 5a of the current collecting electrode 5 on the surface of the solar cell 10. The other electrode contact portion 7b is connected to the current collecting electrode 6 on the back surface of the solar cell 10. When the interconnector 7 is viewed from the side, the shape of the interconnector 7 is such that one electrode contact portion 7a is formed in a step shape at a position higher than the other electrode contact portion 7b!
  • the one electrode contact portion 7a and the other electrode contact portion 7b are composed of an uneven portion 7h and a flat portion 7k.
  • the uneven portion 7h and the flat portion 7k are formed by inserting the flat portion 7k between the plurality of uneven portions 7h. That is, the uneven portions 7h and the flat portions 7k are alternately formed.
  • the flat portion 7k has a flat plate shape as shown in FIG.
  • the uneven portion 7h includes a protruding portion 7i and a linear portion 7j.
  • the projecting portion 7i and the linear portion 7j include a plurality of projecting portions 7i formed of one projection, and the plurality of projecting portions 7i are located between adjacent projecting portions 7i. Are inserted and arranged. That is, the projecting portions 7i and the linear portions 7j are formed alternately.
  • the concavo-convex portion 7h is formed by a plurality of protruding portions 7i, but may be formed by only one protruding portion 7i without using the linear portion 7j.
  • the protruding shape portion 7i has a rounded triangular shape at the top, an arc swelling upward with a radius of curvature r of about 0.1 mm, and a hem at the bottom. Bulging downward It has an arc shape.
  • the height H of the projection 7i is 0.4 mm, and the width Wl between both bottoms of the bottom is 1.5 mm.
  • the linear portion 7j has a flat plate shape, like the flat portion 7k.
  • the thickness t of the interconnector 7 is 0.3 mm as described above.
  • one concavo-convex portion 7h is composed of four protruding portions 7i and three linear portions 7j.
  • the number of the protruding portions 7i that constitute one uneven portion 7h is not limited to this, but the total number is 20 to 40 for each of the electrode contact portions 7a and 7b of the interconnector 7. Is one guideline. Therefore, one interconnector 7 has a guideline of 40 to 80 connectors. Further, as shown in FIG. 12, the number of the protrusion-shaped portions 7i constituting one uneven portion 7h is different depending on each of the uneven portions 7h.
  • the number of uneven portions 7h formed on the electrode contact portions 7a, 7b may be the same as each of the electrode contact portions 7a, 7b, but is not limited thereto.
  • the number of electrode contact portions 7a may be different from five, and the other electrode contact portion 7b may be six.
  • the number of the protruding portions 7i constituting one uneven portion 7h may be different between the one electrode contact portion 7a and the other electrode contact portion 7b, or the length of the flat portion 7k may be different. May be different between the one electrode contact portion 7a and the other electrode contact portion 7b.
  • the pitch P of the plurality of protrusions 7i is 3.5 mm, so the length W2 of the linear portion 7j is 2 mm. That is, the linear shape portion 7j is formed such that the length W2 of the linear shape portion 7j is longer than the width W1 between both bottoms of the bottom of the projection shape portion 7i. Further, the linear portion 7j is formed shorter than the flat portion 7k, and can be distinguished from the flat portion 7k.
  • the edge portions 71 where the electrode contact portions 7a and 7b are adhered to the upper surfaces at both ends of the current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface, respectively, are flat as shown in FIGS. It is formed in a shape.
  • the uneven portion 7h and the flat portion 7k described above are formed to have substantially the same length. However, this is not always necessary.For example, the ratio between the length of the uneven portion 7h and the length of the flat portion 7k is adjusted according to the situation of the current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface.
  • the current collecting electrode 5 has a ratio of 8: 7
  • the current collecting electrode 6 on the back has a ratio of 10:11. Is also good.
  • the value obtained by integrating the lengths of all the concave and convex portions 7h formed on the electrode contact portions 7a and 7b of the interconnector 7 is substantially equal to the value obtained by integrating the lengths of all the flat portions 7k. It is desirable to form the uneven portion 7h and the flat portion 7k in such a way as to make it easier.
  • the interconnector 7 As a specific method of manufacturing the interconnector 7, first, a copper wire or an invar wire having a width of ⁇ mm and a thickness of 0.3mm is immersed in a solder bath having a desired composition, and is wound at a constant speed. Pull out. Then, the interconnector 7 whose surface is covered with solder is bent to form an electrode contact constituted by the uneven portion 7h composed of the above-mentioned protrusion 7i and the linear portion 7j, a flat portion 7k and an edge portion 71. Parts 7a and 7b are formed.
  • the inter-cell portion 7c of the interconnector 7 forms a stress release having a shape as shown in FIGS.
  • the stress release is a crank-shaped component formed in the interconnector 7 in advance, and has a function of relieving stresses such as various stresses applied to the interconnector 7 by releasing them in a direction with little effect.
  • RU This stress release is formed in the direction of arrangement of the solar cells 10 so as to have a length of about the thickness of the solar cells 10.
  • the interconnector 7 is connected to the solar cell 10 to form a solar cell. That is, as shown in FIGS. 7 to 9, the flat portion 7 k, the linear portion 7 j and the edge portion 71 formed on one electrode contact portion 7 a of the interconnector 7 are combined with the bus bar part 5 a of the solar cell 10. And soldered to the surface.
  • This bonding is specifically performed as follows. First, one electrode contact portion 7a of the interconnector 7 whose entire surface is covered with solder is set so as to be in contact with the bus bar portion 5a of the solar cell 10 also covered with solder. Then, hot air of about 400 ° C is blown onto the entire interconnector 7 to melt the solder in the parts that are in contact with each other, and then cool and solidify the interconnector 7 and the solar cells 10. And are integrated.
  • a solar cell module as shown in FIG. 9 is formed. That is, first, a plurality of solar cells 10 having one electrode contact portion 7a of the interconnector 7 attached to the surface are arranged.
  • the flat portion 7k formed on the other electrode contact portion 7b of the interconnector 7 has a linear shape.
  • the portion 7j and the edge portion 71 are brought into contact with the surface of the current collecting electrode 6 on the back surface of the adjacent solar cell 10 and are adhered with solder.
  • This bonding is specifically performed as follows. First, the other electrode contact portion 7b of the interconnector 7, which is attached to the bus bar portion 5a of the solar cell 10 and whose entire surface is covered with solder, is covered with the same solder of the adjacent solar cell 10. It is set so as to be in contact with the current collecting electrode 6 on the back surface. Then, hot air of about 400 ° C is blown to the entire interconnector 7 to melt the solder in the parts that are in contact with each other, and then cool and solidify to form the interconnector 7 and the solar cell. And 10 are integrated to form a solar cell module.
  • the interconnector 7 and the solar cell are heated by a SUS plate heated to a high temperature (see reference numeral 8 shown in FIG. 5 of the first embodiment). This is a method of sandwiching the pond cell 10 and melting the solder.
  • a plurality of solar cells 10 provided with the interconnector 7 described above are used as a solar cell module product.
  • the solar cell module is formed between the transparent substrate and the back cover.
  • the front surface which is the light receiving surface of the solar cell 10
  • a transparent plate such as a glass plate and the back cover with the transparent substrate facing the transparent substrate.
  • a super-straight method for enclosing a plurality of solar cells 10 provided with is used.
  • the transparent filler for example, PVB (polybutyrol), which has a small decrease in light transmittance, and EVA (ethylene butyl acetate) excellent in meta-humidity are used.
  • the interconnector 7 is formed with a plurality of uneven portions 7h having the protruding portions 7i. Therefore, during heating and cooling in the manufacturing process of the solar cell module, the expansion and contraction of the protrusions 7i due to heat hardly occurs in the protrusion direction and hardly occurs in the direction parallel to the surface of the solar cell 10 immediately. Therefore, as the thickness of the interconnector 7 is increased to reduce the resistance loss, the cross section of the interconnector 7 is increased. Due to the increase in the product, the expansion and contraction of the interconnector 7 in the direction parallel to the surface of the solar cell 10 can be suppressed even if the compressive stress increases according to the thickness.
  • the interconnector 7 is oriented parallel to the surface of the solar cell 10. The expansion and contraction can be suppressed. Therefore, it is possible to prevent the semiconductor substrate 1 of the solar battery cell 10 from being significantly warped, or the cells from being cracked or the electrodes being peeled off during the manufacturing process of the solar battery module. Therefore, a decrease in manufacturing yield can be prevented, and the thickness of the interconnector 7 can be increased, so that the resistance loss of the solar cell module can be reduced and the FF can be increased.
  • a flat portion 7k is inserted between the concavo-convex portions 7h of the interconnector 7 adjacent to each other.
  • the interconnector 7 can be firmly fixed to the collecting electrodes 5 and 6, and the interconnector 7 serves to reinforce the strength of the collecting electrodes 5 and 6.
  • the strength of the electrodes 5, 6 can be increased.
  • the presence of the flat portion 7k in the interconnector 7 makes it possible to carry by vacuum suction and transfer, thereby improving the productivity of the solar cell module.
  • the uneven portion 7h of the interconnector 7 is formed by inserting a linear shape portion 7j between a plurality of projecting shape portions 7i adjacent to each other. Therefore, by bonding this linear portion 7j to the upper surfaces of the current collecting electrodes 5 and 6, the interconnector 7 can be fixedly fixed to the current collecting electrodes 5 and 6 in the same manner as the flat portion 7k. Further, since the interconnector 7 plays a role of reinforcing the strength of the current collecting electrodes 5 and 6, the strength of the current collecting electrodes 5 and 6 can be further enhanced.
  • the edge portion 71 has a flat shape, the interconnector 7 can be firmly fixed to the current collecting electrodes 5 and 6 of the solar cell using this flat portion. .
  • the linear shape portion 7j is formed such that the length W2 of the linear shape portion 7j is longer than the width W1 between both bottom portions of the bottom of the projection shape portion 7i. Therefore, while maintaining the effect of reducing the warpage of the semiconductor substrate 1 due to the projections 7i of the projections and depressions 7h, the interconnector 7 can be firmly fixed to the current collecting electrode while the current collecting is performed. The strength of the electrodes 5 and 6 can be increased.
  • a stress release is formed in inter-cell portion 7 c of interconnector 7. Therefore, when arranging a plurality of solar cells, or when encapsulating the arranged plurality of solar cells between a transparent substrate and a back cover with a transparent filler, the interconnector 7 is connected to the solar cells 10.
  • the stress generated in the interconnector 7 can be released by holding down the edge. Therefore, it is possible to greatly reduce cell cracking, force 4 and the like that occur when the interconnector 7 presses the edge of the solar cell 10. Further, even if the expansion of the interconnector 7 increases due to thermal expansion, expansion and contraction of the interconnector 7 in the direction in which the solar cells 10 are arranged can be suppressed.
  • the semiconductor substrate i of the solar cell: LO it is possible to prevent the semiconductor substrate i of the solar cell: LO from causing a large warp, a cell crack, an electrode peeling, and the like. Furthermore, even after the completion of the solar cell module, even if the interconnector 7 thermally expands due to direct sunlight or the like, expansion and contraction of the interconnector 7 in the arrangement direction of the solar cell 10 can be suppressed. Similarly, even if the transparent filling material expands and contracts between the front transparent substrate and the back cover, expansion and contraction of the interconnector 7 in the arrangement direction of the solar cell 10 can be suppressed. Therefore, the reliability of the solar cell module can be improved and the life can be prolonged.
  • the inter-cell portion 7c of the inter-connector 7 has a shape of the force inter-cell portion 7c forming a stress release.
  • the present invention is not limited to this, and may be, for example, a linear shape.
  • the electrode contact portions 7a and 7b of the interconnector 7 are formed with the concavo-convex portions 7h and the flat portions 7k each including the protruding portions 7i and the linear portions 7j. It has been done.
  • the inventor has performed various trials in the process of deriving such a configuration plan, and the details of the trials will be described next. In this trial, for convenience, reference numerals of the respective components of the solar cell and the solar cell module according to the present embodiment are used.
  • a semiconductor substrate made of a P-type silicon substrate such as monocrystalline silicon or polycrystalline silicon having a square shape of about 155 mm on a side and a thickness of about 0.24 mm and an interconnector having a width of 2 mm were used.
  • the present invention relates to a solar cell module configured to be used.
  • the thickness of the interconnector 7 was set to 0.3 mm, and the electrode contact portions 7a and 7b of the interconnector 7 were provided with uneven portions.
  • a continuous sine curve with a peak-to-peak height of 0.4mm and a pitch of 3.5mm was formed.
  • the continuous sine curve with a peak-to-peak height of 0.4 mm and a pitch of 3.5 mm formed at the electrode contact parts 7a and 7b has a height of 0.4 mm and a width between the bottom skirts of 3 mm.
  • the top of 5mm can be regarded as a convex waveform close to a rounded triangular waveform. In this convex waveform, the width between the bottom hem portions is about 9 times the height, so that the width between the bottom hem portions is too long compared to the height, and the width of the interconnector 7 is reduced.
  • the configuration of the interconnector 7 is the configuration of the present embodiment described above.
  • the semiconductor substrate 1 does not warp and the adhesive strength between the interconnector 7 and the current collecting electrodes 5 and 6 can be ensured.
  • the height H of the projection 7i is 0.4 mm, and the width W1 between the bottoms of the bottom is 1.5 mm, which is different from the trial 1.
  • the width W1 between the bottoms of the bottom of the part 7i is about four times the height H, and the expansion and contraction force of the interconnector 7 due to the heat generated by the interconnector 7 It is unlikely to occur in a direction parallel to the surface of the solar cell 1 and is considered to be due to the body.
  • the interconnector 7 of Trial 2 was excellent in the above-described embodiment, which was not easily adopted. That is, the projecting portion 7i of the uneven portion 7h of the interconnector 7 is formed such that the width between both bottoms of the bottom of the projecting portion 7i is approximately four times the height of the projecting portion 7i.
  • the expansion and contraction of the projection-shaped portion 7i of the uneven portion 7h can be effectively caused along the projection direction. Therefore, the expansion and contraction of the interconnector 7 in the direction parallel to the surface of the solar cell 10 can be effectively suppressed, and the warpage of the semiconductor substrate 1 can be effectively reduced, and the productivity can be reduced. Can be prevented from being hindered.
  • the top of the protruding portion 7i is formed in an arc shape having a radius of curvature r of about 0.1 mm because the molded interconnector is formed by using a hydraulic press. 7 is also a force that is effective in ensuring that the mold has no catching force.
  • the height of the protruding portion 7i formed in the interconnector 7 is preferably low. Therefore, in Trial 3, the thickness of the interconnector was set to 0.3 mm, and the width between the bottom hem portions of the electrode contact portions 7a and 7b of the interconnector 7 was approximately four times the height of the projection-shaped portion 7i. In this state, a projection 7i having a height of 0.2 mm was formed. That is, the protrusion 7i has a height of 0.2 mm and a width between both bottom hem portions of 0.75 mm. In this state, although warpage occurs somewhat, warpage can be suppressed by setting the pitch of the protruding portions 7i to 2.5 mm.
  • the height of the projection 7i is smaller than 0.2 mm, the interconnector 7 having the projection 7i formed thereon is bonded to the current collecting electrodes 5 and 6 of the solar battery cell 10. Then, when the entire surface of the interconnector 7 is covered with a solder and adhered to the current collecting electrodes 5 and 6 of the solar cell 10, the uneven portions 7 h formed on the electrode contact portions 5 and 6 of the interconnector 7 are formed. Solder clogged the space formed between the projection 7i and the surfaces of the current collecting electrodes 5 and 6, and the effect of forming the irregularities 7h on the electrode contact portions 7a and 7b of the interconnect connector 7 was exhibited. There was a problem that it was not possible. Therefore, considering the productivity of the solar cell module, The height of the protrusion 7i of the uneven portion 7h formed on the electrode contact portions 7a and 7b of one connector 7 is desirably 0.2 mm or more.
  • the interconnector 7 of the present embodiment when the collector electrodes 5, 6 and the interconnector 7 are bonded to each other, the interconnector 7 that is entirely covered with a solder can be used.
  • the space formed between the projection-shaped portion 7i of the uneven portion 7h formed on 7 and the collecting electrodes 5 and 6 can be maintained, and the effect of reducing the warpage of the semiconductor substrate 1 can be sufficiently obtained. .
  • the solar cell and the solar cell module of the present invention can be applied to the semiconductor substrate of the solar cell in the manufacturing process of the solar cell or the solar cell module even if the thickness of the interconnector is increased in order to reduce the resistance loss. It can be effectively used to prevent large warpage, cell cracking, electrode peeling, and the like, and to prevent a reduction in manufacturing yield.

Abstract

In a solar battery module wherein a plurality of solar battery cells are arranged and the adjacent solar battery cells are connected by an interconnector, an uneven part is formed on the interconnector. Alternatively, in the solar battery module wherein the plurality of solar battery cells are arranged and the adjacent solar battery cells are connected by the interconnector, the uneven parts and flat parts are alternately formed a plurality of times on the interconnector.

Description

明 細 書  Specification
太陽電池及び太陽電池モジュール  Solar cell and solar cell module
技術分野  Technical field
[0001] 本発明は太陽電池、及び、太陽電池モジュールに関し、詳しくは、太陽電池セルの 表面に備えられた集電電極にインターコネクタを接続した太陽電池、及び、インター コネクタによって複数の太陽電池セルを接続した太陽電池モジュールに関する。 背景技術  The present invention relates to a solar cell and a solar cell module, and more particularly, to a solar cell in which an interconnector is connected to a current collecting electrode provided on the surface of the solar cell, and a plurality of solar cells by the interconnector The present invention relates to a solar cell module to which is connected. Background art
[0002] 太陽電池モジュールは、複数の太陽電池セルを接続して形成されて 、る。この太 陽電池モジュールに使用される従来の太陽電池セルは、図 13, 14に示すように、半 導体基板 11とその表裏に備えられた集電電極 15, 16とで構成されている。太陽電 池セル 20に用いられる半導体基板 11には、 N型領域 12と P型領域 13が形成され、 N型領域 12と P型領域 13との界面部分に半導体接合部 14が形成されている。又、 N型領域 12の表面上には表面の集電電極 15が、 P型領域 13の表面上には裏面の 集電電極 16が設けられている。表面の集電電極 15は、グリッド状のフィンガー部 15 b、及び、インターコネクタ 17を接続するバスバー部 15aで構成されている。又、裏面 の集電電極 16は、インターコネクタ 7を接続するための銀電極 (不図示)、及び、該銀 電極を除く裏面のほぼ全面に形成された集電用のアルミニウム電極 (不図示)で構成 されている。  [0002] A solar cell module is formed by connecting a plurality of solar cells. As shown in FIGS. 13 and 14, a conventional solar cell used in this solar cell module is composed of a semiconductor substrate 11 and current collecting electrodes 15 and 16 provided on the front and back thereof. An N-type region 12 and a P-type region 13 are formed on a semiconductor substrate 11 used for a solar cell 20, and a semiconductor junction 14 is formed at an interface between the N-type region 12 and the P-type region 13. . On the surface of the N-type region 12, a current collecting electrode 15 on the front surface is provided, and on the surface of the P-type region 13, a current collecting electrode 16 on the back surface is provided. The current collecting electrode 15 on the front surface is composed of a grid-shaped finger portion 15 b and a bus bar portion 15 a connecting the interconnector 17. The current collecting electrode 16 on the back surface is composed of a silver electrode (not shown) for connecting the interconnector 7 and an aluminum current collecting electrode (not shown) formed on almost the entire back surface excluding the silver electrode. It is composed of
[0003] 従来の太陽電池モジュールでは、複数の太陽電池セル 20の接続には、図 13, 14 に示すようなインターコネクタ 17が用いられている。インターコネクタ 17は、両端に電 極接触部 17a, 17bを備えており、平角状の銅箔やインバール (鉄とニッケルの合金) 等で形成され、その表面全体がハンダで被覆されている。このインターコネクタ 17を 用いて、図 15に示すように、複数の太陽電池セル 20が接続されている。即ち、一方 の電極接触部 17aが、太陽電池セル 20の表面の集電電極 15のバスバー部 15a上 の略全長にわたつて配設され、その複数箇所をバスバー部 15aと接合することによつ て表面の集電電極 15のノ スバー部 15aに接続されている。又、他方の電極接触部 1 7bが、裏面の集電電極 16にハンダ付けにて接続されて!、る。 [0004] 図 13, 14に示すように、インターコネクタ 17の一方の電極接触部 17aが、太陽電 池セル 20の表面の集電電極 15のバスバー部 15aに接続されたものを、本明細書で は、太陽電池と称する。つまり、太陽電池モジュールは、図 15に示すように、配列さ れた太陽電池において、互いに隣接する一方の太陽電池の表面に接続されたイン ターコネクタ 17の他方の電極接触部 17bが、互いに隣接する他方の太陽電池の、裏 面の集電電極 16に接続されることにより形成されているのである。このような太陽電 池モジュールは、種々のものが提案されている(例えば、特許文献 1を参照)。特許文 献 1に記載の太陽電池装置は、インターコネクタとして、撚り線を使用したものである 特許文献 1 :特開平 11 251613号公報 In a conventional solar cell module, an interconnector 17 as shown in FIGS. 13 and 14 is used to connect a plurality of solar cells 20. The interconnector 17 has electrode contact portions 17a and 17b at both ends, and is made of rectangular copper foil or invar (an alloy of iron and nickel) or the like, and its entire surface is covered with solder. Using this interconnector 17, a plurality of solar cells 20 are connected as shown in FIG. That is, one of the electrode contact portions 17a is disposed over substantially the entire length of the current collecting electrode 15 on the surface of the solar cell 20 on the bus bar portion 15a, and a plurality of portions are joined to the bus bar portion 15a. Connected to the nose bar 15a of the current collecting electrode 15 on the front side. Also, the other electrode contact portion 17b is connected to the current collecting electrode 16 on the back by soldering! RU As shown in FIGS. 13 and 14, one of the electrode contacts 17a of the interconnector 17 connected to the bus bar 15a of the current collecting electrode 15 on the surface of the solar battery cell 20 is referred to in this specification. Will be referred to as solar cells. That is, in the solar cell module, as shown in FIG. 15, in the arranged solar cells, the other electrode contact portions 17b of the interconnector 17 connected to the surface of one of the adjacent solar cells are adjacent to each other. It is formed by being connected to the current collecting electrode 16 on the back surface of the other solar cell. Various types of such solar cell modules have been proposed (for example, see Patent Document 1). The solar cell device described in Patent Document 1 uses a stranded wire as an interconnector Patent Document 1: Japanese Patent Application Laid-Open No. H11 251613
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0005] 上述したように、太陽電池の製造過程では、インターコネクタの電極接触部を太陽 電池セルの集電電極に接続するのに、ハンダ付けが用いられる。このハンダ付けの 際、ハンダ付けの熱により、インターコネクタの電極接触部及び太陽電池セルの集電 電極の温度が上昇し、この上昇した温度が常温に戻る際に、太陽電池セルを構成し ている半導体基板に圧縮応力が印加されることは、周知の事実である。  [0005] As described above, in the process of manufacturing a solar cell, soldering is used to connect the electrode contact portion of the interconnector to the current collecting electrode of the solar cell. At the time of this soldering, the heat of the soldering raises the temperature of the electrode contact portion of the interconnector and the current collecting electrode of the solar cell, and when the raised temperature returns to normal temperature, the solar cell is formed. It is a well-known fact that a compressive stress is applied to a given semiconductor substrate.
[0006] ところで、従来の太陽電池モジュールでは、インターコネクタにおける抵抗損失のた め、太陽電池モジュールを構成する一つ一つの太陽電池セルの出力を犠牲にして おり、太陽電池モジュールの出力としては、それらを構成する太陽電池セルの出力 に見合うだけの十分な出力が得られていないという重大な問題があった。それに加え て、今後の太陽電池モジュールの出力向上とコスト低減のためには、太陽電池セル の面積増大が効果的であるが、太陽電池セルの面積を増大すると、発生する電流が 増大するのみならず、表面の集電電極が長くなるので、インターコネクタにおける抵 抗損失はさらに増大し、事態はさらに深刻化するという問題があった。この解決策とし ては、インターコネクタの断面積を増加する方法が考えられ、この断面積を増加する 方法として、インターコネクタの表面積を増大させる方法がある。しかし、インターコネ クタの表面積を増大させると、太陽電池セルの表面における受光面積が減少して出 力が減少するという問題が生じる。そこで、インターコネクタの断面積を増加するには 、インターコネクタの厚みを厚くするよりほかに方法がない。 [0006] By the way, in the conventional solar cell module, the output of each solar cell constituting the solar cell module is sacrificed due to resistance loss in the interconnector. There was a serious problem that the output was not enough to match the output of the solar cells that make up them. In addition, increasing the area of the solar cell is effective for improving the output and reducing the cost of the solar cell module in the future, but if the area of the solar cell increases, the generated current will only increase. However, since the current collecting electrode on the surface becomes longer, the resistance loss in the interconnector further increases, and the problem becomes more serious. One solution to this problem is to increase the cross-sectional area of the interconnector. One way to increase the cross-sectional area is to increase the surface area of the interconnector. However, when the surface area of the interconnect is increased, the light receiving area on the surface of the photovoltaic cell is reduced and the output is reduced. The problem of reduced force arises. Therefore, the only way to increase the cross-sectional area of the interconnector is to increase the thickness of the interconnector.
[0007] ところが、インターコネクタの厚みを厚くすると、以下にあげる 2つの要因から、半導 体基板に印加される上述した圧縮応力が増大する。第 1に、インターコネクタの厚み を厚くするとインターコネクタの断面積が増加するので、その圧縮応力は厚みに応じ て大きくなる。第 2に、太陽電池モジュールの製造過程で、表面の集電電極とインタ 一コネクタとの溶着の際に、ホットエアーゃリフロー、ハンダ鏝等の熱力 表面の集電 電極のハンダまで伝わりに《なる。そのため、表面の集電電極とインターコネクタと の溶着に時間が力かることから、熱膨張によりインターコネクタの伸びが大きくなり、半 導体基板に印加される圧縮応力が増大する。このように、インターコネクタの厚みを 厚くすると、上述した圧縮応力が増大するので、半導体基板に大きな反りが発生し、 セル割れや電極剥がれ等を誘発して製造歩留りが低下するという問題があった。  [0007] However, when the thickness of the interconnector is increased, the above-mentioned compressive stress applied to the semiconductor substrate increases due to the following two factors. First, increasing the thickness of the interconnector increases the cross-sectional area of the interconnector, so that its compressive stress increases with the thickness. Second, in the process of manufacturing the solar cell module, when welding the current collecting electrode on the surface and the interconnector, the heat is transmitted to the hot current collecting electrode on the surface, such as hot air reflow and a soldering iron. . For this reason, the welding between the current collecting electrode on the surface and the interconnector takes a long time, so that the interconnector expands due to thermal expansion, and the compressive stress applied to the semiconductor substrate increases. As described above, when the thickness of the interconnector is increased, the above-described compressive stress increases, so that a large warpage occurs in the semiconductor substrate, which causes a problem such as cell cracking and electrode peeling, thereby lowering the manufacturing yield. .
[0008] この点に関して、特許文献 1に記載の太陽電池装置は、インターコネクタとして、撚 り線を用いている。インターコネクタとして撚り線を用いることは、上記の問題における ひとつの解決策ではある力 撚り線であっても全体として直線状の一本の電線である ことに変わりはなぐその効果は、小規模な程度に留まるといわざるを得ない。つまり、 集電電極とインターコネクタとの間に隙間が無い為、例えば、表面全体をハンダで被 覆した撚り線を用いたインターコネクタを使用すると、表面全体をノヽンダで被覆して ヽ る集電電極にインターコネクタを溶着する際、ホットエアーゃリフロー、ハンダ鏝等の 熱により膨張した撚り線が、膨張したままの状態で表面の集電電極に固定されてしま う。すると、本来、加熱により上昇した温度が下がって撚り線が収縮する際に、撚り線 がほどけることによる撚り線の伸びによって、半導体基板の反りを低減する効果を出 すはずの撚り線が、固定されてしまってほどけない。そのため、インターコネクタとして 撚り線を用いた場合、半導体基板の反りを低減する効果は激減され、結局、撚り線が 収縮する際に半導体基板に反りを生じさせてしまう。即ち、撚り線が半導体基板の反 りを低減する効果を発揮する前に、ハンダによって撚り線が太陽電池セルの表面の 集電電極に固定されてしまうので、半導体基板の反りを低減する効果はほとんど無く なってしまうのである。従って、撚り線をインターコネクタに用いようとすると、集電電極 に接触する部分のみにハンダを被覆した特殊な構造のインターコネクタを用いなけ ればならず、インターコネクタ製作に余分な工程が必要となり、コストも増大してしまう 。又、そもそも、撚り線をインターコネクタに加工する工程自体が複雑であり、手間が かかることになる。 [0008] In this regard, the solar cell device described in Patent Document 1 uses a stranded wire as the interconnector. The use of a stranded wire as an interconnector is one solution to the problem described above. Even if a power stranded wire is used, it is still a single linear wire as a whole. I have to say that it stays at a level. In other words, since there is no gap between the current collecting electrode and the interconnector, for example, if an interconnector using a stranded wire whose entire surface is covered with solder is used, the entire surface is covered with a solder. When the interconnector is welded to the electrode, the stranded wire that has expanded due to the heat of hot air reflow, a soldering iron, etc., is fixed to the current collecting electrode on the surface in the expanded state. Then, when the temperature increased by heating decreases and the stranded wire shrinks, the stranded wire that should have the effect of reducing the warpage of the semiconductor substrate due to the elongation of the stranded wire by unwinding the stranded wire, It is fixed and cannot be undone. Therefore, when a stranded wire is used as the interconnector, the effect of reducing the warpage of the semiconductor substrate is drastically reduced, and eventually, when the stranded wire shrinks, the semiconductor substrate is warped. That is, before the stranded wire exhibits the effect of reducing the warpage of the semiconductor substrate, the stranded wire is fixed to the current collecting electrode on the surface of the solar cell by the solder. It is almost gone. Therefore, if you try to use a stranded wire for the interconnector, Therefore, an interconnector having a special structure in which solder is coated only on the portion that comes into contact with the solder must be used, and an extra process is required for the manufacture of the interconnector, and the cost increases. In addition, the process of processing the stranded wire into the interconnector itself is complicated and time-consuming.
[0009] そこで、本発明は上記の問題を解決するためになされたものであって、太陽電池セ ルの面積増大に伴って抵抗損失の低減の為にインターコネクタの厚みを厚くしても、 太陽電池モジュールの製造過程で、太陽電池セルの半導体基板に大きな反りが生 じたり、セル割れや電極剥がれ等が発生したりするのを防止でき、製造歩留りの低下 を防止できると共に、抵抗損失を低減して F. F. (フィルファクター:光電変換効率)を 向上した太陽電池または太陽電池モジュールを提供することを目的として!/、る。 課題を解決するための手段  [0009] Therefore, the present invention has been made to solve the above problems, and even if the thickness of the interconnector is increased to reduce the resistance loss with the increase in the area of the solar cell, In the manufacturing process of the solar cell module, it is possible to prevent the semiconductor substrate of the solar cell from being greatly warped, cracking the cell, peeling off the electrodes, etc., thereby preventing a reduction in manufacturing yield and reducing a resistance loss. With the aim of providing a solar cell or solar cell module with reduced and improved FF (fill factor: photoelectric conversion efficiency)! Means for solving the problem
[0010] 上記の問題を解決するためになされた本発明の太陽電池は、集電電極が形成され た太陽電池セルを有し、前記太陽電池セルの前記集電電極にインターコネクタが接 続された太陽電池において、前記インターコネクタに凹凸部が形成されていることを 特徴としている。 [0010] A solar cell of the present invention made to solve the above problem has a solar cell on which a current collecting electrode is formed, and an interconnector is connected to the current collecting electrode of the solar cell. In the above solar cell, the interconnector is formed with an uneven portion.
[0011] 又、本発明の太陽電池モジュールは、複数の太陽電池セルが配列されていると共 に、互いに隣接する前記太陽電池セル力 Sインターコネクタによって接続されている太 陽電池モジュールにおいて、前記インターコネクタに凹凸部が形成されていることを 特徴としている。  [0011] In addition, the solar cell module of the present invention is a solar cell module in which a plurality of solar cells are arranged and connected by the solar cell power S interconnectors adjacent to each other. It is characterized in that the interconnector has an uneven portion.
[0012] 又、上記の太陽電池や太陽電池モジュールは、これらに用いられる前記インターコ ネクタの、前記太陽電池セルの表面又は裏面に位置する部分の少なくとも一部が凹 凸形状に形成されるようにするのが好ま 、。  [0012] Further, the above-mentioned solar cell or solar cell module is configured such that at least a part of a portion of the interconnector used for the solar cell or the solar cell, which is located on a front surface or a back surface of the solar cell, is formed in a concave-convex shape. I prefer to.
[0013] 又、上記の太陽電池は、これらに用いられる前記インターコネクタの、前記太陽電 池セルの表面に位置する部分の一部、又は、前記太陽電池セルの裏面に位置する 部分の一部のみが、凹凸状に形成されるようにしてもょ 、。  [0013] Further, in the above solar cell, a part of a portion of the interconnector used for the solar cell, which is located on the front surface of the solar cell, or a part of a portion which is located on the back surface of the solar cell. Only the irregularities may be formed.
[0014] 又、上記の太陽電池モジュールは、これらに用いられる前記インターコネクタの、前 記太陽電池セルの表面に位置する部分の一部、及び、前記太陽電池セルの裏面に 位置する部分の一部のみが、凹凸状に形成されるようにしてもょ 、。 [0015] 上記の太陽電池や太陽電池モジュールは、前記インターコネクタに前記凹凸部が 形成されているので、当該太陽電池モジュールの製造過程における加熱冷却に際し て、前記インターコネクタの凹凸部分の伸縮が、凹凸方向に沿って生じやすぐ前記 太陽電池セルの表面と平行な方向には生じにくい。そのため、抵抗損失の低減の為 に前記インターコネクタの厚みを厚くすることに伴 、、前記インターコネクタの断面積 の増加により、圧縮応力が厚みに応じて大きくなつても、或いは、前記インターコネク タの厚みを厚くすることに伴い、表面電極と前記インターコネクタとの溶着に時間がか 力つて熱膨張により前記インターコネクタの伸びが大きくなつても、前記インターコネ クタが前記太陽電池セルの表面と平行な方向に伸縮するのを抑えることができる。従 つて、当該太陽電池モジュールの製造過程で、前記太陽電池セルの半導体基板に 大きな反りが生じたり、セル割れや電極剥がれ等が発生したりするのを防止すること ができる。又、前記インターコネクタに形成された前記凹凸部により、前記表面の集 電電極と前記インターコネクタとの間に部分的な隙間が生じるため、全体をハンダで 被覆した前記インターコネクタを用いても、半導体基板の反りを低減する効果を十分 得ることができる。そのため、製造歩留りの低下を防止できると共に、前記インターコ ネクタを厚くすることができることから、当該太陽電池モジュールの抵抗損失を低減し て F. F.を高めることができる。 [0014] In the above-mentioned solar cell module, the interconnector used for the above-mentioned solar cell module may include a part of a part located on the front surface of the solar cell and a part of a part located on the back surface of the solar cell. Only the part may be formed in an uneven shape. [0015] In the above-described solar cell or solar cell module, since the uneven portion is formed in the interconnector, expansion and contraction of the uneven portion of the interconnector during heating and cooling in the manufacturing process of the solar cell module causes It is unlikely to occur in the direction parallel to the surface of the photovoltaic cells as soon as it occurs along the uneven direction. Therefore, as the thickness of the interconnector is increased to reduce the resistance loss, the cross-sectional area of the interconnector is increased, so that the compressive stress is increased in accordance with the thickness, or As the thickness of the interconnect becomes thicker, even though the welding of the surface electrode and the interconnector takes a long time and the expansion of the interconnector becomes large due to thermal expansion, the interconnector may be in contact with the surface of the solar cell. Expansion and contraction in the parallel direction can be suppressed. Therefore, it is possible to prevent the semiconductor substrate of the solar battery cell from being greatly warped, or the cell from being cracked or the electrode from being peeled off during the manufacturing process of the solar battery module. Further, since the uneven portion formed on the interconnector causes a partial gap between the current collecting electrode on the surface and the interconnector, even if the interconnector is entirely covered with solder, The effect of reducing the warpage of the semiconductor substrate can be sufficiently obtained. Therefore, a decrease in manufacturing yield can be prevented, and the thickness of the interconnect can be increased, so that the resistance loss of the solar cell module can be reduced and the FF can be increased.
[0016] 又、上記の太陽電池や太陽電池モジュールの前記インターコネクタに形成される 凹凸形状としては、波型形状とするようにしてもよぐ或いは、アーチ型又は反アーチ 型とするようにしてもよい。又、これらの凹凸形状が、部分的な突起型又は、部分的な へこみ型とするようにしてちょ 、。  [0016] The unevenness formed on the interconnector of the solar cell or the solar cell module may be a corrugated shape or an arched or anti-arched shape. Is also good. In addition, the shape of these concavities and convexities should be a partial projection type or a partial depression type.
[0017] 又、上記の太陽電池や太陽電池モジュールの前記インターコネクタに形成される 凹凸形状のピッチが、太陽電池セルの 1辺の長さ未満で、凹凸の高さが 2mm以下と するのが好ましい。  [0017] Further, it is preferable that the pitch of the irregularities formed on the interconnector of the solar cell or the solar cell module is less than the length of one side of the solar cell and the height of the irregularities is 2 mm or less. preferable.
[0018] 又、上記の太陽電池や太陽電池モジュールは、前記インターコネクタに平坦部が 形成され、前記凹凸部と前記平坦部とが交互に複数回形成されてなつてもよい。  In the above-described solar cell or solar cell module, a flat portion may be formed in the interconnector, and the uneven portion and the flat portion may be alternately formed a plurality of times.
[0019] 上記の太陽電池や太陽電池モジュールは、前記インターコネクタに前記複数の凹 凸部が形成されている。そのため、当該太陽電池モジュールの製造過程における加 熱冷却に際して、この凹凸部分の熱による伸縮力 凹凸方向に沿っては生じやすぐ 前記太陽電池セルの表面と平行な方向には生じにくい。そのため、抵抗損失の低減 の為に前記インターコネクタの厚みを厚くすることに伴い、前記インターコネクタの断 面積の増加により、圧縮応力が厚みに応じて大きくなつても、或いは、表面電極と前 記インターコネクタとの溶着に時間が力かって熱膨張により前記インターコネクタの伸 びが大きくなつても、前記インターコネクタが前記太陽電池セルの表面と平行な方向 に伸縮するのを抑えることができる。従って、当該太陽電池モジュールの製造過程で 、前記太陽電池セルの半導体基板に大きな反りが生じたり、セル割れや電極剥がれ 等が発生したりするのを防止することができる。そのため、製造歩留りの低下を防止 できると共に、前記インターコネクタを厚くすることができることから、当該太陽電池モ ジュールの抵抗損失を低減して F. F.を高めることができる。 [0019] In the above solar cell or solar cell module, the plurality of concave and convex portions are formed in the interconnector. For this reason, processing during the manufacturing process of the solar cell module is performed. At the time of thermal cooling, the expansion and contraction force due to the heat of the concave and convex portions is generated along the concave and convex direction, and is hardly generated in the direction parallel to the surface of the solar cell. Therefore, as the thickness of the interconnector is increased in order to reduce the resistance loss, even if the compressive stress increases according to the thickness due to the increase in the cross-sectional area of the interconnector, Even if the expansion of the interconnector increases due to thermal expansion due to the time required for welding to the interconnector, expansion and contraction of the interconnector in a direction parallel to the surface of the solar cell can be suppressed. Therefore, in the manufacturing process of the solar cell module, it is possible to prevent the semiconductor substrate of the solar cell from being significantly warped, or the cells from being cracked or the electrodes from being peeled off. Therefore, a decrease in manufacturing yield can be prevented, and the thickness of the interconnector can be increased, so that the resistance loss of the solar cell module can be reduced and the FF can be increased.
[0020] 又、上記の太陽電池や太陽電池モジュールは、前記インターコネクタの相隣接する 前記凹凸部間に前記平坦部が挿入されて形成されているので、この平坦部を前記 集電電極の上面に接着することにより、前記インターコネクタを前記集電電極にしつ 力り固定することができると共に、前記インターコネクタが前記集電電極の強度を補 強する役割を果たすので、前記集電電極の強度を増強することができる。又、前記ィ ンターコネクタにこの平坦部が存在することにより、前記インターコネクタを真空吸着 して搬送することが可能となり、当該太陽電池モジュールの生産性を向上することが できる。 Further, in the above-described solar cell or solar cell module, since the flat portion is formed by inserting the flat portion between the concavo-convex portions adjacent to the interconnector, the flat portion is formed on the upper surface of the current collecting electrode. By bonding to the current collector, the interconnector can be pressed and fixed to the current collecting electrode, and the interconnector plays a role of reinforcing the strength of the current collecting electrode. Can be enhanced. In addition, the presence of the flat portion in the interconnector allows the interconnector to be vacuum-adsorbed and transported, thereby improving the productivity of the solar cell module.
[0021] 又、上記の太陽電池や太陽電池モジュールにおいて、前記インターコネクタの前 記凹凸部は、頂部が丸みを帯びた 1個の突起でなる突起形状部が単独で形成され てなり、又は、頂部が丸みを帯びた 1個の突起でなる突起形状部が複数形成されると ともに、複数の前記突起形状部が相隣接する該突起形状部間に直線形状部を挿入 して形成されてなるようにするのが好ま U、。  [0021] Further, in the above-mentioned solar cell or solar cell module, the above-mentioned uneven portion of the interconnector is formed by independently forming a protrusion-shaped portion having a single rounded top. A plurality of protrusion-shaped portions each having a single rounded top are formed, and the plurality of protrusion-shaped portions are formed by inserting a linear shape portion between adjacent ones of the protrusion-shaped portions. U, like to do.
[0022] このように、前記複数の突起形状部が相隣接する該突起形状部間に前記直線形 状部を挿入して形成されて 、ると、この直線形状部を前記集電電極の上面に接着す ることにより、上記の平坦部と同様、前記インターコネクタを前記集電電極にしっかり 固定することができると共に、前記インターコネクタが前記集電電極の強度を補強す る役割を果たすので、前記集電電極の強度をさらに増強することができる。 As described above, when the plurality of protrusions are formed by inserting the linear part between the adjacent protrusions, the linear part is formed on the upper surface of the current collecting electrode. By adhering to the flat portion, the interconnector can be firmly fixed to the current collecting electrode similarly to the flat portion, and the interconnector reinforces the strength of the current collecting electrode. Therefore, the strength of the current collecting electrode can be further enhanced.
[0023] 又、前記突起形状部は、該突起形状部の頂部が丸みを帯びるように形成されるの で、油圧プレスを用いて前記インターコネクタを成型する際に、成型された前記インタ 一コネクタが型に引っ掛力つて卷回してしまうようなこともなぐ当該太陽電池や太陽 電池モジュールの生産性が低下するのを抑制することができる。  [0023] Further, since the projection-shaped portion is formed so that the top of the projection-shaped portion is rounded, when the interconnector is molded using a hydraulic press, the molded interconnector is formed. It is possible to suppress a decrease in the productivity of the solar cell or the solar cell module, which is prevented from being wound by a hooking force on a mold.
[0024] 又、上記の太陽電池や太陽電池モジュールにおいて、前記インターコネクタの前 記凹凸部の前記直線形状部は、前記凹凸部の前記突起形状部の底部の幅よりも長 く、前記平坦部の長さよりも短く形成されるようにするのが好ま 、。  [0024] In the above solar cell or solar cell module, the linear portion of the uneven portion of the interconnector is longer than the width of the bottom of the projecting portion of the uneven portion, and Preferably, it is formed to be shorter than the length of the.
[0025] このようにすることにより、前記凹凸部の前記突起形状部による上述した半導体基 板の反りを低減する効果を維持しつつ、前記インターコネクタを前記集電電極にしつ 力り固定することができると共に、前記集電電極の強度を増強することができる。  [0025] With this configuration, the interconnector is fixedly fixed to the current collecting electrode while maintaining the effect of reducing the warpage of the semiconductor substrate due to the projection-shaped portion of the uneven portion. And the strength of the current collecting electrode can be enhanced.
[0026] 又、上記の太陽電池や太陽電池モジュールにおいて、前記インターコネクタの前 記凹凸部の前記突起形状部は、前記突起形状部の底部の幅が前記突起形状部の 高さの略 4倍となるように形成されるようにするのが好ま 、。  [0026] In the above-mentioned solar cell or solar cell module, the protrusion-shaped portion of the uneven portion of the interconnector has a width at the bottom of the protrusion-shaped portion approximately four times the height of the protrusion-shaped portion. It is preferred to be formed so that.
[0027] このようにすることにより、当該太陽電池モジュールの製造過程における加熱冷却 に際して、前記凹凸部の前記突起形状部の伸縮を、突起方向に沿って効果的に生 じさせることができ、その結果、前記インターコネクタが前記太陽電池セルの表面と平 行な方向に伸縮するのを効果的に抑えることができる。従って、上述した半導体基板 の反りを効果的に低減することができる。  [0027] By doing so, expansion and contraction of the protrusion-shaped portion of the uneven portion can be effectively caused along the protrusion direction during heating and cooling in the manufacturing process of the solar cell module. As a result, expansion and contraction of the interconnector in a direction parallel to the surface of the solar cell can be effectively suppressed. Therefore, the above-described warpage of the semiconductor substrate can be effectively reduced.
[0028] 又、上記の太陽電池や太陽電池モジュールにおいて、前記インターコネクタは、前 記太陽電池セルの前記集電電極の両端部上面と接着する部分が平坦に形成される ようにするのが好ましい。このようにすることにより、この平坦な部分を用いて、前記ィ ンターコネクタを前記太陽電池セルの表面や裏面にしつ力りと固着することができる。  [0028] In the above solar cell or solar cell module, it is preferable that the interconnector is formed such that portions of the solar cell that adhere to the upper surfaces of both ends of the current collecting electrode are flat. . By doing so, the interconnector can be firmly fixed to the front surface or the back surface of the solar cell using the flat portion.
[0029] 上述した太陽電池モジュールにおいて、前記太陽電池セル及び前記インターコネ クタを、透明基板と裏面カバーとの間に挟んで太陽電池モジュールを構成することが できる。このようにすることにより、前記太陽電池セルの表面や裏面を保護することが できる。  [0029] In the above-described solar cell module, the solar cell module and the interconnector can be configured such that the solar cell module is sandwiched between a transparent substrate and a back cover. By doing so, the front and back surfaces of the solar cell can be protected.
[0030] 上記の太陽電池モジュールのインターコネクタの一部分であって、当該インターコ ネクタにより接続された隣接する太陽電池セル間となる部分が直線形状となるように 形成してもよい。或いは、インターコネクタの一部分であって、当該インターコネクタに より接続された隣接する太陽電池セル間となる部分に、当該インターコネクタにかか る種々のストレスを緩和させるストレスリリースが形成されるようにしてもよ!、。 [0030] A part of the interconnector of the solar cell module, The portion between adjacent solar cells connected by the connector may be formed in a linear shape. Alternatively, a stress release that relieves various stresses on the interconnector is formed in a portion of the interconnector between adjacent solar cells connected by the interconnector. You can!
[0031] ストレスリリースとは、予め、前記インターコネクタに形成したクランク形状の構成部 分であり、前記インターコネクタにかかる種々のストレスを緩和させる機能を有してい る。このストレスリリースは、前記太陽電池セルの配列方向に、前記太陽電池セルの 厚さ程度の長さで形成される。  [0031] The stress release is a crank-shaped component formed in the interconnector in advance, and has a function of alleviating various stresses applied to the interconnector. The stress release is formed in the direction in which the solar cells are arranged in a length of about the thickness of the solar cells.
[0032] このストレスリリース力 前記インターコネクタの前記太陽電池セル間となる部分に形 成されていることにより、複数の当該太陽電池を配列する際、或いは、配列した複数 の当該太陽電池を透明な充填剤を用いて透明基板と裏面カバーとの間に封入する 際に、前記インターコネクタが前記太陽電池セルのエッジを押さえつけることによって 前記インターコネクタに生じる応力を逃がすことが可能となる。そのため、前記インタ 一コネクタが前記太陽電池セルのエッジを押さえつけることによって発生するセル割 れ、力 4ナ等を大幅に低減することができる。又、加熱、冷却等による膨張、収縮が生じ ても、これらの膨張、収縮による長さの変化を影響の少ない方向に逃がすことができ 、前記インターコネクタが前記太陽電池セルの配列方向に伸縮するのを抑えることが できる。そのため、当該太陽電池モジュールの製造過程で、前記太陽電池セルの半 導体基板に大きな反りが生じたり、セル割れや電極剥がれ等が発生したりするのを防 止することができる。又、このストレスリリースによる更なる利点は、当該太陽電池モジ ユールが完成した後において、直射日光等によって前記インターコネクタが熱膨張し たり、或いは、前記太陽電池セルの表面の透明基板と裏面カバーとの間の透明な充 填材料が伸縮したりしても、前記インターコネクタが前記太陽電池セルの配列方向に 伸縮するのを抑えることができることである。そのため、当該太陽電池モジュールの信 頼性を高め、寿命を延ばすことができる。  [0032] The stress release force is formed at a portion between the solar cells of the interconnector, so that a plurality of the solar cells are arranged or a plurality of the arranged solar cells are transparent. When sealing between the transparent substrate and the back cover using a filler, the stress generated in the interconnector can be released by the interconnector pressing down the edge of the solar cell. For this reason, cell cracking and force of four, which are generated when the interconnector presses the edge of the solar cell, can be significantly reduced. Further, even if expansion or contraction occurs due to heating, cooling, or the like, the change in length due to the expansion or contraction can be released in a direction having little effect, and the interconnector expands and contracts in the arrangement direction of the solar cells. Can be suppressed. Therefore, in the manufacturing process of the solar cell module, it is possible to prevent the semiconductor substrate of the solar cell from being significantly warped, or the cells from being cracked or the electrodes from being peeled off. A further advantage of the stress release is that after the solar cell module is completed, the interconnector thermally expands due to direct sunlight or the like, or the transparent substrate on the front surface of the solar cell and the back cover can be used. Even if the transparent filler material expands and contracts during this time, it is possible to suppress expansion and contraction of the interconnector in the arrangement direction of the solar cells. Therefore, the reliability of the solar cell module can be improved, and the life can be prolonged.
[0033] 上記の太陽電池や太陽電池モジュールにおいて、前記インターコネクタは、前記 太陽電池セルのエッジ部分が平坦であり、その平坦部を除く部分の当該インターコ ネクタの表側及び裏側に凹凸が形成されるように構成してもよ ヽ。このよう〖こすること により、平坦なエッジ部分を用いて、前記インターコネクタを前記太陽電池セルの表 面や裏面にしつ力りと固着することができる。 [0033] In the above-described solar cell or solar cell module, the interconnector has a flat edge portion of the solar cell, and irregularities are formed on a front side and a rear side of the interconnector except for the flat portion. It may be configured as follows. Doing something like this Thereby, the interconnector can be firmly fixed to the front and back surfaces of the solar cell using the flat edge portion.
発明の効果  The invention's effect
[0034] 本発明に力かる太陽電池または太陽電池モジュールによれば、太陽電池セルの面 積増大に伴って抵抗損失の低減の為にインターコネクタの厚みを厚くしても、太陽電 池モジュールの製造過程で、太陽電池セルの半導体基板に大きな反りが生じたり、 セル割れや電極剥がれ等が発生したりするのを防止でき、製造歩留りの低下を防止 できると共に、抵抗損失を低減して F. F.を向上させることができる。  [0034] According to the solar cell or the solar cell module of the present invention, even if the thickness of the interconnector is increased to reduce the resistance loss with the increase in the area of the solar cell, the solar cell module can be used. In the manufacturing process, it is possible to prevent the semiconductor substrate of the solar battery cell from being significantly warped, cell breakage, electrode peeling, and the like, thereby preventing a reduction in manufacturing yield and reducing resistance loss to reduce FF. Can be improved.
図面の簡単な説明  Brief Description of Drawings
[0035] [図 1]図 1は、第 1の実施の形態における太陽電池の平面図である。 FIG. 1 is a plan view of a solar cell according to a first embodiment.
[図 2]図 2は、図 1の A— A線断面図である。  FIG. 2 is a sectional view taken along line AA of FIG. 1.
[図 3]図 3は、第 1の実施の形態における太陽電池モジュールの断面図である。  FIG. 3 is a cross-sectional view of the solar cell module according to the first embodiment.
[図 4]図 4は、第 1の実施の形態における太陽電池モジュールに使用されるインターコ ネクタのセル間部の拡大図である。  FIG. 4 is an enlarged view of an inter-cell portion of an interconnector used in the solar cell module according to the first embodiment.
[図 5]図 5は、第 1の実施の形態における太陽電池モジュールの製造に使用されるリ フロー方式の説明図である。  FIG. 5 is an explanatory diagram of a reflow method used for manufacturing the solar cell module according to the first embodiment.
[図 6]図 6 (a)〜図 6 (h)は、インターコネクタの電極接触部の形状の他の例を示した 説明図である。  6 (a) to 6 (h) are explanatory diagrams showing other examples of the shape of the electrode contact portion of the interconnector.
[図 7]図 7は、第 2の実施の形態における太陽電池の平面図である。  FIG. 7 is a plan view of a solar cell according to a second embodiment.
[図 8]図 8は、図 7の A'— A'線断面図である。  FIG. 8 is a sectional view taken along the line A′-A ′ in FIG. 7.
[図 9]図 9は、第 2の実施の形態における太陽電池モジュールの断面図である。  FIG. 9 is a cross-sectional view of a solar cell module according to a second embodiment.
[図 10]図 10は、図 8の部分拡大図である。  FIG. 10 is a partially enlarged view of FIG.
[図 11]図 11は、インターコネクタの凹凸部の形状を示した図である。  FIG. 11 is a diagram showing a shape of an uneven portion of the interconnector.
[図 12]図 12は、インターコネクタの凹凸部の他の例の形状を示した図である。  FIG. 12 is a view showing the shape of another example of the uneven portion of the interconnector.
[図 13]図 13は、従来例の太陽電池の平面図である。  FIG. 13 is a plan view of a conventional solar cell.
[図 14]図 14は、図 13の B— B線断面図である。  FIG. 14 is a cross-sectional view taken along line BB of FIG. 13.
[図 15]図 15は、従来例の太陽電池モジュールの断面図である。  FIG. 15 is a cross-sectional view of a conventional solar cell module.
符号の説明 半導体基板 Explanation of reference numerals Semiconductor substrate
N型領域  N-type region
P型領域  P-type area
半導体接合部  Semiconductor junction
表面の集電電極a バスバー部 Current collecting electrode a Busbar part on the surface
b フィンガー部 b Finger part
裏面の集電電極 インターコネクタa, 7b 電極接触部c セル間部 Current collecting electrode on the back side Interconnector a, 7b Electrode contact part c Intercell part
d, 7e エッジ部d, 7e edge
f, 7g 遊び部f, 7g play section
h 凹凸部h Uneven part
1 突起形状部1 Protrusion
j 直線形状部j Straight section
k 平坦部k flat part
1 エッジ部 1 Edge
高温 SUS板 High temperature SUS plate
0, 10a, 10b 太陽電池セル1 半導体基板0, 10a, 10b Solar cell 1 Semiconductor substrate
2 N型領域2 N-type region
3 P型領域3 P-type area
4 半導体接合部4 Semiconductor junction
5 表面の集電電極5 Current collecting electrode on the surface
5a バスバー部5a Busbar section
5b フィンガー部5b finger part
6 裏面の集電電極 17 インターコネクタ 6 Current collecting electrode on the back 17 Interconnector
17a, 17b 電極接触部  17a, 17b Electrode contact
17c セル間部  17c Between cells
20 太陽電池セル  20 solar cells
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0037] 以下、本発明の第 1の実施の形態に力かる太陽電池、及び、太陽電池モジュール の実施の形態について、図面を参照して説明する。 Hereinafter, embodiments of a solar cell and a solar cell module according to the first embodiment of the present invention will be described with reference to the drawings.
第 1の実施の形態  First embodiment
[0038] 図 1は、第 1の実施の形態における太陽電池の平面図であり、図 2はその断面図で あり、図 3は、本実施の形態における太陽電池モジュールの断面図である。本実施の 形態において、太陽電池は、 1個の太陽電池セル 10に 1個のインターコネクタ 7を接 続して構成される。又、太陽電池モジュールは、配列された複数の太陽電池セル 10 を、インターコネクタ 7を用いて直列接続して構成される。即ち、太陽電池モジュール は、配列された上記太陽電池において、互いに隣接する一方の太陽電池の表面に、 一端 7aが接続されたインターコネクタ 7の他端 7bを、互いに隣接する他方の太陽電 池の裏面に接続することにより構成されるのである。  FIG. 1 is a plan view of a solar cell according to the first embodiment, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is a cross-sectional view of a solar cell module according to the present embodiment. In the present embodiment, the solar cell is configured by connecting one interconnector 7 to one solar cell 10. The solar cell module is configured by connecting a plurality of arranged solar cells 10 in series using an interconnector 7. That is, the solar cell module includes, in the arrayed solar cells, the other end 7b of the interconnector 7 having one end 7a connected to the surface of one adjacent solar cell and the other end of the adjacent solar cell. It is configured by connecting to the back surface.
[0039] 図 1、図 2及び図 3において、本実施の形態の太陽電池及び太陽電池モジュール に用いられる太陽電池セル 10は、半導体基板 1と、その表裏に形成される表面の集 電電極 5及び裏面の集電電極 6とで構成される。  In FIG. 1, FIG. 2, and FIG. 3, a solar cell 10 used in the solar cell and the solar cell module according to the present embodiment includes a semiconductor substrate 1 and a current collecting electrode 5 on the surface formed on the front and back surfaces thereof. And a current collecting electrode 6 on the back surface.
[0040] 半導体基板 1は、一辺が 155mm程度の正方形状で、厚みが 0. 2〜0. 3mm程度 の単結晶シリコンや多結晶シリコン等の P型シリコン基板で形成される。この P型シリコ ン基板の表層には PZN接合が形成される。この PZN接合の形成は、具体的には、 N型の不純物を含む溶液を P型シリコン基板の表面に塗布して行われる。あるいは、 PZN接合の形成は、この P型シリコン基板を気相中に置いて、 800〜900°C程度の 温度によりその表面力 N型の不純物を熱拡散させることにより、 P型シリコン基板の 表層に不純物拡散層を形成することで行なわれる。こうして形成された N型拡散面を 、太陽電池セル 10の受光面である表面とし、不拡散面を裏面とする。即ち、半導体 基板 1内に N型領域 2と P型領域 3が形成され、 N型領域 2と P型領域 3との界面部分 に半導体接合部 4が形成される。受光面である表面には、金属酸化物等の反射防止 膜を形成しておくことが望ましい。尚、この半導体基板 1は、シリコン以外に単結晶ガ リウム砒素等で形成してもよい。 [0040] The semiconductor substrate 1 is formed of a P-type silicon substrate such as single-crystal silicon or polycrystalline silicon having a square shape with a side of about 155 mm and a thickness of about 0.2 to 0.3 mm. A PZN junction is formed on the surface of the P-type silicon substrate. Specifically, the formation of the PZN junction is performed by applying a solution containing N-type impurities to the surface of the P-type silicon substrate. Alternatively, the PZN junction is formed by placing this P-type silicon substrate in the gas phase and thermally diffusing N-type impurities at a temperature of about 800 to 900 ° C to the surface of the P-type silicon substrate. This is performed by forming an impurity diffusion layer on the substrate. The N-type diffusion surface thus formed is referred to as the front surface, which is the light receiving surface of the solar cell 10, and the non-diffusion surface is referred to as the back surface. That is, an N-type region 2 and a P-type region 3 are formed in the semiconductor substrate 1, and an interface between the N-type region 2 and the P-type region 3 is formed. A semiconductor junction 4 is formed at this time. It is desirable to form an antireflection film such as a metal oxide on the surface that is the light receiving surface. The semiconductor substrate 1 may be formed of single crystal gallium arsenide or the like other than silicon.
[0041] 上記の半導体基板 1には、図 1、図 3に示すように、 N型領域 2の表面上に表面の 集電電極 5が形成され、 P型領域 3の表面上に裏面の集電電極 6が形成される。表面 の集電電極 5は、グリッド状のフィンガー部 5bと、インターコネクタ 7を接続するバスバ 一部 5aとで構成される。  As shown in FIGS. 1 and 3, a collecting electrode 5 on the front surface is formed on the surface of the N-type region 2, and a collecting electrode on the back surface is formed on the surface of the P-type region 3, as shown in FIGS. Electrode 6 is formed. The collecting electrode 5 on the surface is composed of a grid-like finger portion 5b and a bus bar portion 5a for connecting the interconnector 7.
[0042] これらの表面の集電電極 5及び裏面の集電電極 6は、具体的には、次のようにして 形成される。即ち、電極形成工程において、上記の半導体基板 1の受光面にはグリツ ド状に、金属またはそれに準じる物質を集電電極 5としてパターニングし、真空蒸着 法やスクリ—ン印刷法を用いて集電電極 5を形成する。また、裏面には略全面に、金 属またはそれに準じる物質を集電電極 6としてパターニングし、真空蒸着法やスクリ ーン印刷法を用いて集電電極 6を形成する。表面の集電電極 5は、上述したように、 インターコネクタ 7を接続するためのバスバー部 5aと、これに交差するように分岐して 形成されるグリッド状のフィンガー部 5bとで構成される。バスバー部 5aは、半導体基 板 1の略全面を横切るようにして二本平行に形成される。フィンガー部 5bは、バスバ 一部 5aと直角に交差するようにして、基板 1の略全長にわたって複数本形成される。 バスバー部 5aの幅は、例えば 2mm程度であり、フィンガー部 5bの幅は、例えば 0. 2 mm程度である。この表面の集電電極 5は、例えば、銀粉末、ガラスフリット、結合剤、 及び、溶剤等力も成るペーストをスクリーン印刷して 700〜800°C程度の温度で焼き 付け、全体をノヽンダ層で被覆することにより形成される。  [0042] The current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface are specifically formed as follows. That is, in the electrode forming step, the light-receiving surface of the semiconductor substrate 1 is patterned in a grid shape with a metal or a substance similar thereto as the current collecting electrode 5, and the current is collected using a vacuum deposition method or a screen printing method. The electrode 5 is formed. A metal or a substance similar thereto is patterned as a current collecting electrode 6 on substantially the entire back surface, and the current collecting electrode 6 is formed using a vacuum deposition method or a screen printing method. As described above, the current collecting electrode 5 on the front surface is composed of the bus bar portion 5a for connecting the interconnector 7, and the grid-like finger portion 5b branched and formed to cross the bus bar portion 5a. The two busbar portions 5a are formed in parallel so as to cross substantially the entire surface of the semiconductor substrate 1. A plurality of finger portions 5b are formed over substantially the entire length of the substrate 1 so as to intersect the bus bar portion 5a at right angles. The width of the bus bar portion 5a is, for example, about 2 mm, and the width of the finger portion 5b is, for example, about 0.2 mm. The current collecting electrode 5 on this surface is, for example, screen-printed with silver powder, glass frit, a binder, and a paste having a force such as a solvent and baked at a temperature of about 700 to 800 ° C. It is formed by coating.
[0043] 又、裏面の集電電極 6は、インターコネクタ 7を接続するための銀電極 (不図示)と、 それを除くほぼ全面に形成された集電用のアルミニウム電極 (不図示)とで構成され 、銀電極はハンダ層で被覆される。  [0043] The current collecting electrode 6 on the back surface is composed of a silver electrode (not shown) for connecting the interconnector 7, and a current collecting aluminum electrode (not shown) formed on almost the entire surface except the silver electrode. When configured, the silver electrode is covered with a solder layer.
[0044] 上述したように、上記の太陽電池セル 10にインターコネクタ 7を接続して、図 1及び 図 2に示すような太陽電池が形成される。又、この太陽電池を複数個配列して直列接 続することにより、図 3に示すような太陽電池モジュールが形成される。太陽電池モジ ユールにおける太陽電池セル 10相互の間隔は、 2〜3mm程度である。 [0045] インターコネクタ 7は、図 3に示すように、セル間部 7cを間に挟んで一方の電極接触 部 7aと他方の電極接触部 7bとで構成される。インターコネクタ 7を側面視すると、イン ターコネクタ 7の形状は、一方の電極接触部 7aが他方の電極接触部 7bよりも高 、位 置にある階段形状に形成されている。一方の電極接触部 7aと他方の電極接触部 7b とは、共に全体に亘つて波状に上下に屈曲させた形状をしている。又、太陽電池セ ル 10の表面の集電電極 5のバスバー部 5aに接続されるインターコネクタ 7の一方の 電極接触部 7aの 2つのエッジ部 7d, 7d、及び、太陽電池セル 10の裏面の集電電極 6に接続されるインターコネクタ 7の他方の電極接触部 7bの 2つのエッジ部 7e, 7eは 、平坦な形状としている。このよう〖こすること〖こより、インターコネクタ 7の電極接触部 7 a, 7bを上下に屈曲させることによる効果を維持しつつ、太陽電池セル 10へ強固に 接着することができる。 As described above, the interconnector 7 is connected to the solar cell 10 to form a solar cell as shown in FIGS. 1 and 2. Further, by arranging a plurality of solar cells and connecting them in series, a solar cell module as shown in FIG. 3 is formed. The interval between the solar cells 10 in the solar cell module is about 2 to 3 mm. As shown in FIG. 3, the interconnector 7 includes one electrode contact portion 7a and the other electrode contact portion 7b with the inter-cell portion 7c interposed therebetween. When the interconnector 7 is viewed from the side, the shape of the interconnector 7 is such that one electrode contact portion 7a is formed higher than the other electrode contact portion 7b and is formed in a step shape. Each of the one electrode contact portion 7a and the other electrode contact portion 7b has a shape which is bent up and down in a wavy shape over the entirety. Also, two edge portions 7d, 7d of one electrode contact portion 7a of the interconnector 7 connected to the bus bar portion 5a of the current collecting electrode 5 on the front surface of the solar cell 10 and the back surface of the solar cell 10 The two edge portions 7e and 7e of the other electrode contact portion 7b of the interconnector 7 connected to the collecting electrode 6 have a flat shape. By doing so, it is possible to firmly adhere to the solar cell 10 while maintaining the effect of bending the electrode contact portions 7a and 7b of the interconnector 7 up and down.
[0046] このインターコネクタ 7は、平角状の銅箔やインバール等で形成される。インターコ ネクタ 7の具体的な製造方法としては、まず、所望の組成のハンダ浴に幅が 2mmで 厚さが 0. 15〜: L Ommの銅線またはインバール線を浸漬し、一定速度で卷取り引き 出す。そして、次に、図 1、図 3に示すように、このインターコネクタ 7の一方の電極接 触部 7a及び他方の電極接触部 7bをその長手方向の全体にわたって、波状に上下 に屈曲させる。波状の屈曲した部分のピッチ pは、バスバー部 5aの長さより短くする 必要があり、本実施の形態では、 3. 5mm程度としている。又、ピークの高さ qは、実 用的な見地から 2mm以下が望ましぐ本実施の形態では、 0. 4mm程度としている。  The interconnector 7 is formed of a rectangular copper foil, invar, or the like. As a specific method of manufacturing the interconnector 7, first, a copper wire or an Invar wire having a width of 2 mm and a thickness of 0.15 to: L Omm is immersed in a solder bath having a desired composition, and wound at a constant speed. put out. Then, as shown in FIGS. 1 and 3, one electrode contact portion 7a and the other electrode contact portion 7b of the interconnector 7 are bent up and down in a wavy manner over the entire length thereof. The pitch p of the wavy bent portion needs to be shorter than the length of the bus bar portion 5a, and is set to about 3.5 mm in the present embodiment. Also, the height q of the peak is set to about 0.4 mm in the present embodiment, which is desirably 2 mm or less from a practical point of view.
[0047] 又、インターコネクタ 7のセル間部 7cには、図 4に示すような形状をしたストレスリリー スを形成する。ストレスリリースとは、予めインターコネクタ 7に形成したクランク形状の 構成部分であり、インターコネクタ 7にかかる種々の応力等のストレスを、影響の少な い方向に逃がすことにより緩和させる機能を有している。このストレスリリースは、太陽 電池セル 10の配列方向に、太陽電池セル 10の厚さ程度の長さとなるように形成する  Further, a stress release having a shape as shown in FIG. 4 is formed in the inter-cell portion 7c of the interconnector 7. The stress release is a crank-shaped component formed in the interconnector 7 in advance, and has a function of relieving stresses such as various stresses applied to the interconnector 7 by escaping in a direction having less influence. . This stress release is formed in the direction of arrangement of the solar cells 10 so as to have a length of about the thickness of the solar cells 10.
[0048] このストレスリリースは、図 4における、落とし込み高さ Xを lmm程度、落とし込み幅 y を 0. 5mm程度としている。太陽電池セル 10間の間隔は 2〜3mm程度であるので、 これらの落とし込み高さ Xや落とし込み幅 yは、太陽電池セル 10の厚みとインターコネ クタ 7の厚みとを十分にカバーすることができる。又、このストレスリリースの前後に遊 び部 7f, 7gを入れるのが好ましぐこの遊び部 7f, 7gの高さ zを 0. 1mm程度とする。 In this stress release, the drop height X is about lmm and the drop width y is about 0.5 mm in FIG. Since the interval between the solar cells 10 is about 2 to 3 mm, the drop height X and the drop width y are determined by the thickness of the solar cells 10 and the interconnect. The thickness of the cutter 7 can be sufficiently covered. The height z of the play portions 7f and 7g, which preferably include the play portions 7f and 7g before and after the stress release, is set to about 0.1 mm.
[0049] 上記のインターコネクタ 7を太陽電池セル 10に接続して太陽電池を形成する。即ち 、図 1、図 2に示すように、インターコネクタ 7の波状の形状をした一方の電極接触部 7 aの谷部分の下端を、太陽電池セル 10aのバスバー部 5aの表面に接触させて、この 接触部分を、ハンダ等を用いてスポット接続し、太陽電池を形成する。  [0049] The above interconnector 7 is connected to solar cell 10 to form a solar cell. That is, as shown in FIGS. 1 and 2, the lower end of the valley portion of one of the corrugated electrode contact portions 7a of the interconnector 7 is brought into contact with the surface of the bus bar portion 5a of the solar cell 10a, The contact portion is spot-connected using solder or the like to form a solar cell.
[0050] この接続は、具体的には次のようにして行なわれる。まず、表面全体がハンダで被 覆されたインターコネクタ 7の一方の電極接触部 7aを、太陽電池セル 10の同じくハン ダで被覆されたバスバー部 5aに接するようにセットする。その上で、インターコネクタ 7 全体に 400°C程度の熱風を吹き付け、相互に接触している部分のハンダ同士をいつ たん融解させた後、冷却 ·固化することでインターコネクタ 7と太陽電池セル 10とを一 体化させる。  [0050] This connection is specifically performed as follows. First, one electrode contact portion 7a of the interconnector 7 whose entire surface is covered with solder is set so as to be in contact with the bus bar portion 5a of the solar cell 10 also covered with solder. Then, hot air of about 400 ° C is blown onto the entire interconnector 7 to melt the solder in the parts that are in contact with each other, and then cool and solidify the interconnector 7 and the solar cells 10. And are integrated.
[0051] 上記のようにして形成された太陽電池を複数個用いて、図 3に示すように、太陽電 池モジュールを形成する。即ち、まず、表面にインターコネクタ 7が取り付けられた複 数個の太陽電池セル 10を配列する。そして、互いに隣接する一方の太陽電池セル 1 Oaのバスバー部 5aに一方の電極接触部 7aが既に接着しているインターコネクタ 7の 、ハンダで被覆された波状の形状をした他方の電極接触部 7bの山部分の上端を、 互いに隣接する他方の太陽電池セル 10bの裏面の集電電極 6の、ハンダで被覆され た銀電極に接するようにセットする。その上で、セットしたインターコネクタ 7に 400°C 程度の熱風を吹き付け、相互に接触している部分のハンダ同士をいつたん融解させ た後、冷却'固化することで、インターコネクタ 7の他方の電極接触部 7bと、太陽電池 セル 10の裏面の集電電極 6とをスポット接続して一体化させ、太陽電池モジュールを 形成する。  Using a plurality of solar cells formed as described above, a solar cell module is formed as shown in FIG. That is, first, a plurality of solar cells 10 with the interconnector 7 attached to the surface are arranged. Then, the other electrode contact portion 7b in the form of a corrugated shape covered with solder of the interconnector 7 in which the one electrode contact portion 7a is already bonded to the bus bar portion 5a of one of the adjacent solar cells 1 Oa The upper end of the crest portion is set so as to be in contact with the silver electrode covered with solder on the current collecting electrode 6 on the back surface of the other solar cell 10b adjacent to each other. Then, hot air of about 400 ° C is blown onto the set interconnector 7 to melt the solder in the part that is in contact with each other, and then cool and solidify, so that the other end of the interconnector 7 is cooled. The electrode contact portion 7b and the current collecting electrode 6 on the back surface of the solar cell 10 are spot-connected and integrated to form a solar cell module.
[0052] 尚、太陽電池セル 10にインターコネクタ 7を接続する方法としては、上記の方法の 他、リフロー方式、或いは、ハンダ鏝を用いた手付けによる方法等もある。リフロー方 式とは、ハンダを融解させる際に熱風を吹き付ける代わりに、図 5に示すように、高温 に熱した SUSの板 8でインターコネクタ 7と太陽電池セル 10とを挟み込み、ハンダを 融解させる方法である。 [0053] 一般に、太陽電池モジュールでは、太陽電池セル 10の表面や裏面を保護する必 要があることから、太陽電池モジュール製品としては、上述したインターコネクタ 7を備 えた複数の太陽電池セル 10を、透明基板と裏面カバーとの間に挟んで太陽電池モ ジュールを構成する。この場合に、例えば、ガラス板等の透明板と裏面カバーとの間 に、太陽電池セル 10の受光面である表面を透明基板に向けて挟み、透明な充填材 料と裏面コートでインターコネクタを備えた複数の太陽電池セルを封入するスーパー ストレート方式が一般に用いられる。ここで透明な充填剤としては、光透過率の低下 の少な ヽ PVB (ポリビュルプチロール)ゃ而湿性に優れた EVA (エチレンビュルァセ タート)等が用いられる。 [0052] As a method of connecting the interconnector 7 to the solar cell 10, in addition to the above-mentioned method, there is a reflow method, a method using a soldering iron, or the like. In the reflow method, instead of blowing hot air when melting the solder, as shown in Fig. 5, the interconnector 7 and the solar cell 10 are sandwiched between the SUS plates 8 heated to a high temperature to melt the solder. Is the way. Generally, in a solar cell module, it is necessary to protect the front and back surfaces of the solar cell 10. Therefore, as a solar cell module product, a plurality of solar cells 10 provided with the interconnector 7 described above are used. The solar cell module is formed between the transparent substrate and the back cover. In this case, for example, the front surface, which is the light receiving surface of the solar cell 10, is sandwiched between a transparent plate such as a glass plate and a back cover with the transparent substrate facing the transparent substrate. A super straight system in which a plurality of provided solar cells are sealed is generally used. Here, as the transparent filler, for example, PVB (polybutyrol), which has a small decrease in light transmittance, and EVA (ethylene buracetate) excellent in metahumidity are used.
[0054] 上記の本実施の形態における太陽電池モジュールでは、インターコネクタ 7の一方 の電極接触部 7a及び他方の電極接触部 7bが、波状に上下に屈曲して構成されて いるので、太陽電池モジュールの製造過程における加熱冷却に際して、一方の電極 接触部 7a又は他方の電極接触部 7bの各屈曲した部分の伸縮は、屈曲された方向 に沿って生じ、太陽電池セル 10の配列方向には生じにくい。そのため、抵抗損失の 低減の為にインターコネクタ 7の厚みを厚くすることに伴い、インターコネクタ 7の断面 積が増加することにより、半導体基板 1に印加される圧縮応力が厚みに応じて大きく なっても、或いは、バスバー部 5aとインターコネクタ 7の一方の電極接触部 7aとの溶 着や、裏面の集電電極 6とインターコネクタ 7の他方の電極接触部 7bとの溶着に時間 がかかって、熱膨張によりインターコネクタ 7の伸びが大きくなつても、インターコネク タ 7が太陽電池セル 10の表面と平行な方向に伸縮するのを抑えることができる。  [0054] In the solar cell module according to the above-described embodiment, one electrode contact portion 7a and the other electrode contact portion 7b of interconnector 7 are configured to bend up and down in a wave shape. During heating and cooling in the manufacturing process, the expansion and contraction of each bent portion of the one electrode contact portion 7a or the other electrode contact portion 7b occurs along the bent direction and hardly occurs in the arrangement direction of the solar cells 10 . Therefore, as the thickness of the interconnector 7 is increased in order to reduce the resistance loss, the cross-sectional area of the interconnector 7 is increased, and the compressive stress applied to the semiconductor substrate 1 is increased in accordance with the thickness. Alternatively, it takes time to weld the bus bar portion 5a to one electrode contact portion 7a of the interconnector 7 and the welding between the current collecting electrode 6 on the back surface and the other electrode contact portion 7b of the interconnector 7, Even if the expansion of the interconnector 7 increases due to thermal expansion, the expansion and contraction of the interconnector 7 in a direction parallel to the surface of the solar cell 10 can be suppressed.
[0055] 従って、太陽電池セル 10の直列抵抗損失を低減するためにインターコネクタ 7の厚 みを厚くしても、太陽電池モジュールの製造過程で、太陽電池セル 10の半導体基板 1に大きな反りが生じたり、セル割れや電極剥がれ等が発生したりするのを防止する ことができる。又、インターコネクタ 7に形成された凹凸部により、表面の集電電極 5と インターコネクタ 7との間に部分的な隙間が形成されるため、全体をノヽンダで被覆し たインターコネクタ 7を用いても、半導体基板 1の反りを低減する効果を十分得ること ができる。そのため、製造歩留りの低下を防止できると共に、インターコネクタ 7を厚く することができること力ら、太陽電池モジュールの抵抗損失を低減して F. F.を高める ことができる。 [0055] Therefore, even if the thickness of the interconnector 7 is increased in order to reduce the series resistance loss of the solar cell 10, large warpage occurs in the semiconductor substrate 1 of the solar cell 10 in the manufacturing process of the solar cell module. And the occurrence of cell cracking, electrode peeling, and the like can be prevented. In addition, since an uneven portion formed on the interconnector 7 forms a partial gap between the current collecting electrode 5 on the surface and the interconnector 7, the interconnector 7 which is entirely covered with a solder is used. However, the effect of reducing the warpage of the semiconductor substrate 1 can be sufficiently obtained. As a result, it is possible to prevent a decrease in the manufacturing yield and to increase the thickness of the interconnector 7, and to reduce the resistance loss of the solar cell module and increase the FF. be able to.
[0056] 又、上記の本実施の形態における太陽電池モジュールでは、インターコネクタ 7の セル間部 7cにストレスリリースが形成されており、又、このストレスリリースの前後に遊 びを設けている。従って、複数の太陽電池を配列する際、或いは、配列した複数の 太陽電池を透明な充填剤により透明基板と裏面カバーの間に封入する際等に、イン ターコネクタ 7が太陽電池セル 10のエッジを押さえつけることによってインターコネク タ 7に生じる応力を逃がすことができる。そのため、インターコネクタ 7が太陽電池セル 10のエッジを押さえつけることによって発生するセル割れ、かけ等を大幅に低減する ことができる。又、インターコネクタ 7の一方の電極接触部 7aと他方の電極接触部 7b とが波状に上下に屈曲して形成されていることと相俟って、熱膨張によりインターコネ クタ 7の伸びが大きくなつても、インターコネクタ 7が太陽電池セル 10の配列方向に伸 縮するのを抑えることができる。そのため、太陽電池モジュールの製造過程で、太陽 電池セル 10の半導体基板 1に大きな反りが生じたり、セル割れや電極剥がれ等が発 生したりするのを防止することができる。さらに、太陽電池モジュールが完成した後に 、直射日光等によってインターコネクタ 7が熱膨張しても、或いは、表面の透明基板と 裏面カバーとの間の透明な充填材料の伸縮が起こっても、インターコネクタ 7が太陽 電池セル 10の配列方向に伸縮するのを抑えることができる。そのため、太陽電池モ ジュールの信頼性を高め、寿命を延ばすことができる。  In the solar cell module according to the present embodiment, a stress release is formed in the inter-cell portion 7c of the interconnector 7, and play is provided before and after the stress release. Therefore, when arranging a plurality of solar cells or enclosing the arranged plurality of solar cells between a transparent substrate and a back cover with a transparent filler, the interconnector 7 is connected to the edge of the solar cell 10. By pressing down, the stress generated in the interconnector 7 can be released. For this reason, cell breaks, splinters, and the like that occur when the interconnector 7 presses the edge of the solar cell 10 can be significantly reduced. In addition, the expansion of the interconnector 7 due to thermal expansion is large, in combination with the fact that the one electrode contact portion 7a and the other electrode contact portion 7b of the interconnector 7 are formed to bend up and down in a wave shape. In any case, expansion and contraction of the interconnector 7 in the arrangement direction of the solar cells 10 can be suppressed. For this reason, it is possible to prevent the semiconductor substrate 1 of the solar cell 10 from being significantly warped, cracking the cell, peeling off the electrode, or the like during the manufacturing process of the solar cell module. Further, even if the interconnector 7 thermally expands due to direct sunlight or the like after completion of the solar cell module, or if the transparent filler material expands and contracts between the front transparent substrate and the back cover, The expansion and contraction of 7 in the arrangement direction of the solar cells 10 can be suppressed. Therefore, the reliability of the solar cell module can be improved and the life can be prolonged.
[0057] 又、上記したようにストレスリリースの前後に遊びを設けたことにより、製造過程およ び太陽電池モジュール完成後に生じる歪等に起因する上下方向や太陽電池セル 1 0の配列方向向きのテンションが太陽電池セル 1にかかっても、これを吸収したり緩和 したりすることができ、上記に挙げたストレスリリースの利点をさらに効果的に発揮する ことができる。  In addition, by providing play before and after the stress release as described above, the vertical direction and the arrangement direction of the solar cells 10 due to the strain and the like generated during the manufacturing process and after the completion of the solar cell module. Even if the tension is applied to the solar battery cell 1, it can be absorbed or reduced, and the advantages of the stress release described above can be more effectively exerted.
[0058] 上記の本実施の形態における太陽電池、又は、太陽電池モジュールでは、インタ 一コネクタ 7における電極接触部 7a, 7bを、上下に屈曲させており、電極接触部 7a, 7bの形状の加工が容易に行なえる利点がある。しかし、電極接触部 7a, 7bの形状 は、これには限られず、凹凸状の形状であれば、いかなる形状をも採用することがで きる。図 6 (a)〜図 6 (h)は、電極接触部 7a, 7bの形状の他の例を模式的に示したも のである。例えば、図 6 (a)に示すような半円を横に連続して並べたアーチ型又は、 図 6 (f)に示すような反アーチ型とした形状、或いは、部分的な突起型又は、部分的 なへこみ型とした形状等を用いるようにしてもよ!、。 [0058] In the solar cell or the solar cell module according to the above-described embodiment, the electrode contact portions 7a and 7b of the interconnector 7 are bent up and down to process the shapes of the electrode contact portions 7a and 7b. Has the advantage that it can be easily performed. However, the shape of the electrode contact portions 7a and 7b is not limited to this, and any shape may be adopted as long as the shape is uneven. FIGS. 6A to 6H schematically show other examples of the shapes of the electrode contact portions 7a and 7b. It is. For example, as shown in FIG. 6 (a), semi-circles are continuously arranged in a row, and are arch-shaped, anti-arch shaped as shown in FIG. 6 (f), or partially projecting or You may use a partially concave shape!
[0059] 又、上記の本実施の形態における太陽電池、又は、太陽電池モジュールでは、ィ ンターコネクタ 7における一方の電極接触部 7a及び他方の電極接触部 7bの各全体 に凹凸部分を設けているが、一方の電極接触部 7a又は他方の電極接触部 7bのみと してもよく、或いは、一方の電極接触部 7a又は他方の電極接触部 7b、若しくは双方 の一部のみに凹凸部分を設けるようにしてもょ 、。  Further, in the solar cell or the solar cell module according to the above-described present embodiment, the entirety of one electrode contact portion 7a and the other electrode contact portion 7b of the interconnect connector 7 is provided with an uneven portion. However, only one electrode contact portion 7a or the other electrode contact portion 7b may be provided, or the one electrode contact portion 7a or the other electrode contact portion 7b, or an uneven portion may be provided only on a part of both. Anyway.
[0060] 又、上記の本実施の形態における太陽電池、又は、太陽電池モジュールでは、ィ ンターコネクタ 7のセル間部 7cには、ストレスリリースを形成している力 セル間部 7c の形状としてはこれには限られず、例えば、直線形状としてもよい。  In the above-described solar cell or solar cell module according to the present embodiment, the inter-cell portion 7c of the inter-connector 7 has a shape of the force inter-cell portion 7c forming a stress release. The present invention is not limited to this, and may be, for example, a linear shape.
第 2の実施の形態  Second embodiment
[0061] 次に、第 2の実施の形態に力かる太陽電池、及び、太陽電池モジュールにつ 、て、 図面を参照して説明する。なお、本第 2の実施の形態では、上記した第 1の実施の形 態に力かる太陽電池、及び、太陽電池モジュールと同一名称の構成には、同一番号 を付す。図 7は、本実施の形態における太陽電池の平面図であり、図 8は図 7の A '— A'線断面図であり、図 3は、本実施の形態における太陽電池モジュールの断面図で ある。本実施の形態において、太陽電池は、 1個の太陽電池セル 10に 1個のインタ 一コネクタ 7を接続して構成されている。又、太陽電池モジュールは、配列された複 数の太陽電池セル 10を、インターコネクタ 7を用いて直列接続して構成されて 、る。 即ち、太陽電池モジュールは、複数の上記太陽電池を配列し、太陽電池の表面に一 端 7aが接続されたインターコネクタ 7の他端 7bを、隣接する太陽電池の裏面に接続 すること〖こより構成されて ヽる。  Next, a solar cell and a solar cell module according to a second embodiment will be described with reference to the drawings. Note that, in the second embodiment, the same reference numerals are given to components having the same names as the solar cells and the solar cell modules that work in the first embodiment described above. 7 is a plan view of the solar cell according to the present embodiment, FIG. 8 is a cross-sectional view taken along line A′-A ′ of FIG. 7, and FIG. 3 is a cross-sectional view of the solar cell module according to the present embodiment. is there. In the present embodiment, the solar cell is configured by connecting one interconnector 7 to one solar cell 10. Further, the solar cell module is configured by connecting a plurality of arranged solar cells 10 in series using an interconnector 7. That is, the solar cell module is configured by arranging a plurality of the above solar cells, and connecting the other end 7b of the interconnector 7 having one end 7a connected to the front surface of the solar cell to the back surface of the adjacent solar cell. Being done.
[0062] 図 7〜図 9において、本実施の形態の太陽電池及び太陽電池モジュールに用いら れる太陽電池セル 10は、半導体基板 1と、その表裏に形成される表面の集電電極 5 及び裏面の集電電極 6とで構成されて 、る。  7 to 9, a solar cell 10 used in the solar cell and the solar cell module according to the present embodiment includes a semiconductor substrate 1, a current collecting electrode 5 formed on the front and back surfaces, and a back surface. The current collecting electrode 6 is composed of:
[0063] 半導体基板 1は、一辺が 155mm程度の正方形状で、厚みが 0. 24mm程度の単 結晶シリコンや多結晶シリコン等の P型シリコン基板で形成されている。この P型シリコ ン基板の表層には PZN接合が形成される。この PZN接合の形成は、具体的には、 N型の不純物を含む溶液を P型シリコン基板の表面に塗布して行われる。あるいは、 PZN接合の形成は、この P型シリコン基板を気相中に置いて、 800〜900°C程度の 温度によりその表面力 N型の不純物を熱拡散させることにより、 P型シリコン基板の 表層に不純物拡散層を形成することで行なわれる。こうして形成された N型拡散面を 、太陽電池セル 10の受光面である表面とし、不拡散面を裏面とする。即ち、半導体 基板 1内に N型領域 2と P型領域 3が形成され、 N型領域 2と P型領域 3との界面部分 に半導体接合部 4が形成されている。受光面である表面には、金属酸化物等の反射 防止膜を形成しておくことが望ましい。尚、この半導体基板 1は、シリコン以外に単結 晶ガリウム砒素等で形成してもよ 、。 The semiconductor substrate 1 is formed of a P-type silicon substrate such as single-crystal silicon or polycrystalline silicon having a square shape with a side of about 155 mm and a thickness of about 0.24 mm. This P-type silicon A PZN junction is formed on the surface of the substrate. Specifically, the formation of the PZN junction is performed by applying a solution containing N-type impurities to the surface of the P-type silicon substrate. Alternatively, the PZN junction is formed by placing this P-type silicon substrate in the gas phase and thermally diffusing N-type impurities at a temperature of about 800 to 900 ° C to the surface of the P-type silicon substrate. This is performed by forming an impurity diffusion layer on the substrate. The N-type diffusion surface thus formed is referred to as the front surface, which is the light receiving surface of the solar cell 10, and the non-diffusion surface is referred to as the back surface. That is, the N-type region 2 and the P-type region 3 are formed in the semiconductor substrate 1, and the semiconductor junction 4 is formed at the interface between the N-type region 2 and the P-type region 3. It is desirable to form an antireflection film such as a metal oxide on the surface that is the light receiving surface. Note that the semiconductor substrate 1 may be formed of single crystal gallium arsenide or the like other than silicon.
[0064] 上記の半導体基板 1には、図 7〜図 9に示すように、 N型領域 2の表面上に表面の 集電電極 5が形成され、 P型領域 3の表面上に裏面の集電電極 6が形成されて ヽる。 表面の集電電極 5は、グリッド状のフィンガー部 5bと、インターコネクタ 7を接続するバ スバ一部 5aとで構成されて 、る。  As shown in FIGS. 7 to 9, the current collecting electrode 5 on the front surface is formed on the surface of the N-type region 2, and the collecting electrode 5 on the rear surface is formed on the surface of the P-type region 3, as shown in FIGS. Electrode 6 is formed. The collecting electrode 5 on the surface is composed of a grid-like finger portion 5b and a bus bar portion 5a for connecting the interconnector 7.
[0065] これらの表面の集電電極 5及び裏面の集電電極 6は、具体的には、次のようにして 形成される。即ち、電極形成工程において、上記の半導体基板 1の受光面にはグリツ ド状に、金属またはそれに準じる物質を集電電極 5としてパターニングし、真空蒸着 法やスクリ—ン印刷法を用いて集電電極 5を形成する。また、裏面には略全面に、金 属またはそれに準じる物質を集電電極 6としてパターニングし、真空蒸着法やスクリ ーン印刷法を用いて集電電極 6を形成する。表面の集電電極 5は、上述したように、 インターコネクタ 7を接続するためのバスバー部 5aと、これに交差するように分岐して 形成されるグリッド状のフィンガー部 5bとで構成される。バスバー部 5aは、半導体基 板 1の略全面を横切るようにして 2本平行に形成される。フィンガー部 5bは、バスバー 部 5aと直角に交差するようにして、基板 1の略全長にわたって複数本形成される。バ スバ一部 5aの幅は、例えば 2mm程度であり、フィンガー部 5bの幅は、例えば 0. 2m m程度である。この表面の集電電極 5は、例えば、銀粉末、ガラスフリット、結合剤、及 び、溶剤等力 成るペーストをスクリーン印刷して 700〜800°C程度の温度で焼き付 け、全体をノ、ンダ層で被覆することにより形成される。 [0066] 又、裏面の集電電極 6は、インターコネクタ 7を接続するための銀電極 (不図示)と、 それを除くほぼ全面に形成された集電用のアルミニウム電極 (不図示)とで構成され 、銀電極はハンダ層で被覆されている。 [0065] The current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface are specifically formed as follows. That is, in the electrode forming step, the light-receiving surface of the semiconductor substrate 1 is patterned in a grid shape with a metal or a substance similar thereto as the current collecting electrode 5, and the current is collected using a vacuum deposition method or a screen printing method. The electrode 5 is formed. A metal or a substance similar thereto is patterned as a current collecting electrode 6 on substantially the entire back surface, and the current collecting electrode 6 is formed using a vacuum deposition method or a screen printing method. As described above, the current collecting electrode 5 on the front surface is composed of the bus bar portion 5a for connecting the interconnector 7, and the grid-like finger portion 5b branched and formed to cross the bus bar portion 5a. The two busbar portions 5a are formed in parallel so as to cross substantially the entire surface of the semiconductor substrate 1. A plurality of finger portions 5b are formed over substantially the entire length of the substrate 1 so as to intersect the bus bar portions 5a at right angles. The width of the bus bar part 5a is, for example, about 2 mm, and the width of the finger part 5b is, for example, about 0.2 mm. The current collecting electrode 5 on this surface is screen-printed, for example, with silver powder, glass frit, a binder, and a paste such as a solvent, and baked at a temperature of about 700 to 800 ° C. It is formed by coating with a solder layer. The current collecting electrode 6 on the back surface includes a silver electrode (not shown) for connecting the interconnector 7 and a current collecting aluminum electrode (not shown) formed on almost the entire surface except the silver electrode. The silver electrode is covered with a solder layer.
[0067] 上述したように、上記の太陽電池セル 10にインターコネクタ 7を接続して、図 7及び 図 8に示すような太陽電池が形成される。この太陽電池を複数個配列して直列接続 することにより、図 9に示すような太陽電池モジュールが形成される。太陽電池モジュ ールにおける太陽電池セル 10相互の間隔は、 2〜 3mm程度である。  As described above, the interconnector 7 is connected to the solar cell 10 to form a solar cell as shown in FIGS. 7 and 8. By arranging a plurality of solar cells and connecting them in series, a solar cell module as shown in FIG. 9 is formed. The interval between the solar cells 10 in the solar cell module is about 2 to 3 mm.
[0068] インターコネクタ 7は、幅が 2mmで厚さが 0. 3mmの銅線またはインバール線で形 成されており、図 8、図 9に示すように、セル間部 7cを間に挟んで一方の電極接触部 7aと他方の電極接触部 7bとで構成されて ヽる。一方の電極接触部 7aは太陽電池セ ル 10の表面の集電電極 5のバスバー部 5aに接続されて!、る。他方の電極接触部 7b は、太陽電池セル 10の裏面の集電電極 6に接続されている。インターコネクタ 7を側 面視すると、インターコネクタ 7の形状は、一方の電極接触部 7aが他方の電極接触 部 7bよりも高 、位置にある階段形状に形成されて!、る。  [0068] The interconnector 7 is formed of a copper wire or an invar wire having a width of 2 mm and a thickness of 0.3 mm. As shown in Figs. 8 and 9, the inter-cell portion 7c is interposed therebetween. It is composed of one electrode contact 7a and the other electrode contact 7b. One electrode contact portion 7a is connected to the bus bar portion 5a of the current collecting electrode 5 on the surface of the solar cell 10. The other electrode contact portion 7b is connected to the current collecting electrode 6 on the back surface of the solar cell 10. When the interconnector 7 is viewed from the side, the shape of the interconnector 7 is such that one electrode contact portion 7a is formed in a step shape at a position higher than the other electrode contact portion 7b!
[0069] 上記の一方の電極接触部 7aと他方の電極接触部 7bは、図 8〜図 10に示すように 、凹凸部 7hと平坦部 7kとで構成されている。これらの凹凸部 7hと平坦部 7kは、複数 の凹凸部 7hの間に平坦部 7kが挿入されて形成されている。即ち、凹凸部 7hと平坦 部 7kとが交互に形成されている。この内、平坦部 7kは、図 10に示すように、平坦な 平板形状をしている。  [0069] As shown in Figs. 8 to 10, the one electrode contact portion 7a and the other electrode contact portion 7b are composed of an uneven portion 7h and a flat portion 7k. The uneven portion 7h and the flat portion 7k are formed by inserting the flat portion 7k between the plurality of uneven portions 7h. That is, the uneven portions 7h and the flat portions 7k are alternately formed. Of these, the flat portion 7k has a flat plate shape as shown in FIG.
[0070] 凹凸部 7hは、図 10に示すように、突起形状部 7iと直線形状部 7jとで構成されてい る。この突起形状部 7iと直線形状部 7jは、 1個の突起でなる突起形状部 7iが複数形 成されるとともに、複数の突起形状部 7iが相隣接する突起形状部 7i間に直線形状部 7jを挿入して配列した状態で形成されている。即ち、突起形状部 7iと直線形状部 7jと が交互に形成されている。本実施の形態では、凹凸部 7hは複数の突起形状部 7iで 形成されているが、 1個の突起形状部 7iのみで直線形状部 7jを用いずに形成しても よい。  [0070] As shown in FIG. 10, the uneven portion 7h includes a protruding portion 7i and a linear portion 7j. The projecting portion 7i and the linear portion 7j include a plurality of projecting portions 7i formed of one projection, and the plurality of projecting portions 7i are located between adjacent projecting portions 7i. Are inserted and arranged. That is, the projecting portions 7i and the linear portions 7j are formed alternately. In the present embodiment, the concavo-convex portion 7h is formed by a plurality of protruding portions 7i, but may be formed by only one protruding portion 7i without using the linear portion 7j.
[0071] 突起形状部 7iは、図 11に示すように、頂部が丸みを帯びた三角形状で、頂部は上 向きに膨らんだ曲率半径 rが 0. 1mm程度の円弧状であり、裾部は下向きに膨らんだ 円弧状である。この突起形状部 7iの高さ Hは 0. 4mm,底部の両裾部間の幅 Wlは 1 . 5mmである。直線形状部 7jは、平坦部 7kと同様、平坦な平板形状をしている。尚、 インターコネクタ 7の厚さ tは、上述の通り 0. 3mmである。 [0071] As shown in Fig. 11, the protruding shape portion 7i has a rounded triangular shape at the top, an arc swelling upward with a radius of curvature r of about 0.1 mm, and a hem at the bottom. Bulging downward It has an arc shape. The height H of the projection 7i is 0.4 mm, and the width Wl between both bottoms of the bottom is 1.5 mm. The linear portion 7j has a flat plate shape, like the flat portion 7k. The thickness t of the interconnector 7 is 0.3 mm as described above.
[0072] 1つの凹凸部 7hは、図 10に示すように、 4個の突起形状部 7iと 3個の直線形状部 7 jとで構成されている。 1つの凹凸部 7hを構成する突起形状部 7iの個数は、これには 限られないが、その合計個数は、インターコネクタ 7の電極接触部 7a, 7bのそれぞれ にっき 20個〜 40個とするのが一つの目安であり、従って、 1本のインターコネクタ 7で は、 40個〜 80個とするのが一つの目安である。又、 1つの凹凸部 7hを構成する突起 形状部 7iの個数は、図 12に示すように、個々の凹凸部 7hによって異なる個数として ちょい。 [0072] As shown in Fig. 10, one concavo-convex portion 7h is composed of four protruding portions 7i and three linear portions 7j. The number of the protruding portions 7i that constitute one uneven portion 7h is not limited to this, but the total number is 20 to 40 for each of the electrode contact portions 7a and 7b of the interconnector 7. Is one guideline. Therefore, one interconnector 7 has a guideline of 40 to 80 connectors. Further, as shown in FIG. 12, the number of the protrusion-shaped portions 7i constituting one uneven portion 7h is different depending on each of the uneven portions 7h.
[0073] 又、電極接触部 7a, 7bに形成する凹凸部 7hの個数は、電極接触部 7a, 7bのそれ ぞれに対して同じ個数としてよいが、これには限られず、例えば、一方の電極接触部 7aに 5個、他方の電極接触部 7bに 6個と、異なるようにしてもよい。この場合、 1個の 凹凸部 7hを構成する突起形状部 7iの個数を、一方の電極接触部 7aと他方の電極 接触部 7bとで異なるようにしてもよぐ或いは、平坦部 7kの長さを、一方の電極接触 部 7aと他方の電極接触部 7bとで異なるようにしてもょ 、。  [0073] The number of uneven portions 7h formed on the electrode contact portions 7a, 7b may be the same as each of the electrode contact portions 7a, 7b, but is not limited thereto. The number of electrode contact portions 7a may be different from five, and the other electrode contact portion 7b may be six. In this case, the number of the protruding portions 7i constituting one uneven portion 7h may be different between the one electrode contact portion 7a and the other electrode contact portion 7b, or the length of the flat portion 7k may be different. May be different between the one electrode contact portion 7a and the other electrode contact portion 7b.
[0074] 又、図 10では、複数の突起形状部 7iのピッチ Pは、 3. 5mmであるので、直線形状 部 7jの長さ W2は、 2mmである。即ち、直線形状部 7jは、この直線形状部 7jの長さ W 2が突起形状部 7iの底部の両裾部間の幅 W1よりも長くなるように形成されている。又 、直線形状部 7jは平坦部 7kよりも短く形成されており、平坦部 7kと区別することがで きる。  Further, in FIG. 10, the pitch P of the plurality of protrusions 7i is 3.5 mm, so the length W2 of the linear portion 7j is 2 mm. That is, the linear shape portion 7j is formed such that the length W2 of the linear shape portion 7j is longer than the width W1 between both bottoms of the bottom of the projection shape portion 7i. Further, the linear portion 7j is formed shorter than the flat portion 7k, and can be distinguished from the flat portion 7k.
[0075] 又、電極接触部 7a, 7bがそれぞれ表面の集電電極 5、裏面の集電電極 6の両端部 上面と接着するエッジ部 71は、図 8〜図 10に示すように、平坦な形状で形成されてい る。  The edge portions 71 where the electrode contact portions 7a and 7b are adhered to the upper surfaces at both ends of the current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface, respectively, are flat as shown in FIGS. It is formed in a shape.
[0076] 又、上述した凹凸部 7hと平坦部 7kとは、略同じ長さとなるように形成される。しかし 、必ずしも、このようにする必要はなぐ例えば、凹凸部 7hの長さと平坦部 7kの長さと の割合を、表面の集電電極 5と裏面の集電電極 6における状況に合わせて、表面の 集電電極 5では 8対 7とし、裏面の集電電極 6では 10対 11として、相異なるようにして もよい。この場合も、インターコネクタ 7の電極接触部 7a, 7bに形成された全ての凹 凸部 7hの長さを積算した値と、同じく全ての平坦部 7kの長さを積算した値とが略等 しくなるようにして、凹凸部 7hと平坦部 7kを形成するのが望ましい。 [0076] The uneven portion 7h and the flat portion 7k described above are formed to have substantially the same length. However, this is not always necessary.For example, the ratio between the length of the uneven portion 7h and the length of the flat portion 7k is adjusted according to the situation of the current collecting electrode 5 on the front surface and the current collecting electrode 6 on the rear surface. The current collecting electrode 5 has a ratio of 8: 7, and the current collecting electrode 6 on the back has a ratio of 10:11. Is also good. Also in this case, the value obtained by integrating the lengths of all the concave and convex portions 7h formed on the electrode contact portions 7a and 7b of the interconnector 7 is substantially equal to the value obtained by integrating the lengths of all the flat portions 7k. It is desirable to form the uneven portion 7h and the flat portion 7k in such a way as to make it easier.
[0077] インターコネクタ 7の具体的な製造方法としては、まず、所望の組成のハンダ浴に幅 力^ mmで厚さが 0. 3mmの銅線またはインバール線を浸漬し、一定速度で卷取り引 き出す。そして、この表面にハンダを被覆したインターコネクタ 7を屈曲させて、上述し た突起形状部 7iと直線形状部 7jとでなる凹凸部 7h、平坦部 7k及びエッジ部 71で構 成される電極接触部 7a, 7bを形成する。  [0077] As a specific method of manufacturing the interconnector 7, first, a copper wire or an invar wire having a width of ^ mm and a thickness of 0.3mm is immersed in a solder bath having a desired composition, and is wound at a constant speed. Pull out. Then, the interconnector 7 whose surface is covered with solder is bent to form an electrode contact constituted by the uneven portion 7h composed of the above-mentioned protrusion 7i and the linear portion 7j, a flat portion 7k and an edge portion 71. Parts 7a and 7b are formed.
[0078] 又、インターコネクタ 7のセル間部 7cは、図 8、図 9に示すような形状をしたストレスリ リースを形成する。ストレスリリースとは、予めインターコネクタ 7に形成したクランク形 状の構成部分であり、インターコネクタ 7に加わる種々の応力等のストレスを、影響の 少な 、方向に逃がすことにより緩和させる機能を有して 、る。このストレスリリースは、 太陽電池セル 10の配列方向に、太陽電池セル 10の厚さ程度の長さとなるように形 成する。  The inter-cell portion 7c of the interconnector 7 forms a stress release having a shape as shown in FIGS. The stress release is a crank-shaped component formed in the interconnector 7 in advance, and has a function of relieving stresses such as various stresses applied to the interconnector 7 by releasing them in a direction with little effect. RU This stress release is formed in the direction of arrangement of the solar cells 10 so as to have a length of about the thickness of the solar cells 10.
[0079] そして、上記のインターコネクタ 7を太陽電池セル 10に接続して太陽電池を形成す る。即ち、図 7〜図 9に示すように、インターコネクタ 7の一方の電極接触部 7aに形成 されている平坦部 7k、直線形状部 7j及びエッジ部 71を、太陽電池セル 10のバスバ 一部 5aの表面に接触させてハンダで接着する。  [0079] Then, the interconnector 7 is connected to the solar cell 10 to form a solar cell. That is, as shown in FIGS. 7 to 9, the flat portion 7 k, the linear portion 7 j and the edge portion 71 formed on one electrode contact portion 7 a of the interconnector 7 are combined with the bus bar part 5 a of the solar cell 10. And soldered to the surface.
[0080] この接着は、具体的には次のようにして行なわれる。まず、表面全体がハンダで被 覆されたインターコネクタ 7の一方の電極接触部 7aを、太陽電池セル 10の同じくハン ダで被覆されたバスバー部 5aに接するようにセットする。その上で、インターコネクタ 7 全体に 400°C程度の熱風を吹き付け、相互に接触している部分のハンダ同士をいつ たん融解させた後、冷却 ·固化することでインターコネクタ 7と太陽電池セル 10とを一 体化させる。  [0080] This bonding is specifically performed as follows. First, one electrode contact portion 7a of the interconnector 7 whose entire surface is covered with solder is set so as to be in contact with the bus bar portion 5a of the solar cell 10 also covered with solder. Then, hot air of about 400 ° C is blown onto the entire interconnector 7 to melt the solder in the parts that are in contact with each other, and then cool and solidify the interconnector 7 and the solar cells 10. And are integrated.
[0081] 上記のようにして形成された図 8に示すような太陽電池を複数個用いて、図 9に示 すような太陽電池モジュールを形成する。即ち、まず、インターコネクタ 7の一方の電 極接触部 7aが表面に取り付けられた複数個の太陽電池セル 10を配列する。そして、 インターコネクタ 7の、他方の電極接触部 7bに形成されている平坦部 7k、直線形状 部 7j及びエッジ部 71を、隣接する太陽電池セル 10の裏面の集電電極 6の表面に接 触させてハンダで接着する。 Using a plurality of the solar cells formed as described above and as shown in FIG. 8, a solar cell module as shown in FIG. 9 is formed. That is, first, a plurality of solar cells 10 having one electrode contact portion 7a of the interconnector 7 attached to the surface are arranged. The flat portion 7k formed on the other electrode contact portion 7b of the interconnector 7 has a linear shape. The portion 7j and the edge portion 71 are brought into contact with the surface of the current collecting electrode 6 on the back surface of the adjacent solar cell 10 and are adhered with solder.
[0082] この接着は、具体的には次のようにして行なわれる。まず、太陽電池セル 10のバス バー部 5aに取り付けられており、表面全体がハンダで被覆されたインターコネクタ 7 の他方の電極接触部 7bを、隣接する太陽電池セル 10の同じくハンダで被覆された 裏面の集電電極 6に接するようにセットする。その上で、インターコネクタ 7全体に 400 °C程度の熱風を吹き付け、相互に接触している部分のハンダ同士をいつたん融解さ せた後、冷却 '固化することでインターコネクタ 7と太陽電池セル 10とを一体ィ匕させ、 太陽電池モジュールを形成する。  [0082] This bonding is specifically performed as follows. First, the other electrode contact portion 7b of the interconnector 7, which is attached to the bus bar portion 5a of the solar cell 10 and whose entire surface is covered with solder, is covered with the same solder of the adjacent solar cell 10. It is set so as to be in contact with the current collecting electrode 6 on the back surface. Then, hot air of about 400 ° C is blown to the entire interconnector 7 to melt the solder in the parts that are in contact with each other, and then cool and solidify to form the interconnector 7 and the solar cell. And 10 are integrated to form a solar cell module.
[0083] 尚、太陽電池セル 10にインターコネクタ 7を接着する方法としては、上記の方法の 他、リフロー方式、或いは、ハンダ鏝を用いた手付けによる方法等もある。リフロー方 式とは、ハンダを融解させる際に熱風を吹き付ける代わりに、高温に熱した SUSの板 (上記した第 1の実施の形態の図 5に示す符号 8参照)でインターコネクタ 7と太陽電 池セル 10とを挟み込み、ハンダを融解させる方法である。  [0083] As a method of bonding the interconnector 7 to the solar cell 10, in addition to the above-mentioned method, there is a reflow method, a method using a soldering iron, or the like. In the reflow method, instead of blowing hot air when melting the solder, the interconnector 7 and the solar cell are heated by a SUS plate heated to a high temperature (see reference numeral 8 shown in FIG. 5 of the first embodiment). This is a method of sandwiching the pond cell 10 and melting the solder.
[0084] 一般に、太陽電池モジュールでは、太陽電池セル 10の表面や裏面を保護する必 要があることから、太陽電池モジュール製品としては、上述したインターコネクタ 7を備 えた複数の太陽電池セル 10を、透明基板と裏面カバーとの間に挟んで太陽電池モ ジュールを構成する。この場合に、例えば、ガラス板等の透明板と裏面カバーとの間 に、太陽電池セル 10の受光面である表面を透明基板に向けて挟み、透明な充填材 料と裏面コートでインターコネクタ 7を備えた複数の太陽電池セル 10を封入するスー パーストレート方式が一般に用いられる。ここで透明な充填剤としては、光透過率の 低下の少な ヽ PVB (ポリビュルプチロール)ゃ而湿性に優れた EVA (エチレンビュル ァセタート)等が用いられる。  [0084] In general, in a solar cell module, it is necessary to protect the front and back surfaces of the solar cell 10, and therefore, as a solar cell module product, a plurality of solar cells 10 provided with the interconnector 7 described above are used. The solar cell module is formed between the transparent substrate and the back cover. In this case, for example, the front surface, which is the light receiving surface of the solar cell 10, is sandwiched between a transparent plate such as a glass plate and the back cover with the transparent substrate facing the transparent substrate. In general, a super-straight method for enclosing a plurality of solar cells 10 provided with is used. Here, as the transparent filler, for example, PVB (polybutyrol), which has a small decrease in light transmittance, and EVA (ethylene butyl acetate) excellent in meta-humidity are used.
[0085] 上記の太陽電池モジュールでは、インターコネクタ 7に突起形状部 7iを有する複数 の凹凸部 7hが形成されている。そのため、太陽電池モジュールの製造過程における 加熱冷却に際して、この突起形状部 7iの熱による伸縮が、突起方向に沿っては生じ やすぐ太陽電池セル 10の表面と平行な方向には生じにくい。そこで、抵抗損失の 低減の為にインターコネクタ 7の厚みを厚くすることに伴い、インターコネクタ 7の断面 積の増加により、圧縮応力が厚みに応じて大きくなつても、インターコネクタ 7が太陽 電池セル 10の表面と平行な方向に伸縮するのを抑えることができる。同様に、表面 電極 5, 6とインターコネクタ 7との溶着に時間が力かって熱膨張によりインターコネク タ 7の伸びが大きくなつても、インターコネクタ 7が太陽電池セル 10の表面と平行な方 向に伸縮するのを抑えることができる。従って、太陽電池モジュールの製造過程で、 太陽電池セル 10の半導体基板 1に大きな反りが生じたり、セル割れや電極剥がれ等 が発生したりするのを防止することができる。そのため、製造歩留りの低下を防止でき ると共に、インターコネクタ 7を厚くすることができることから、太陽電池モジュールの 抵抗損失を低減して F. F.を高めることができる。 [0085] In the above-described solar cell module, the interconnector 7 is formed with a plurality of uneven portions 7h having the protruding portions 7i. Therefore, during heating and cooling in the manufacturing process of the solar cell module, the expansion and contraction of the protrusions 7i due to heat hardly occurs in the protrusion direction and hardly occurs in the direction parallel to the surface of the solar cell 10 immediately. Therefore, as the thickness of the interconnector 7 is increased to reduce the resistance loss, the cross section of the interconnector 7 is increased. Due to the increase in the product, the expansion and contraction of the interconnector 7 in the direction parallel to the surface of the solar cell 10 can be suppressed even if the compressive stress increases according to the thickness. Similarly, even if the time required to weld the surface electrodes 5 and 6 to the interconnector 7 increases the expansion of the interconnector 7 due to thermal expansion, the interconnector 7 is oriented parallel to the surface of the solar cell 10. The expansion and contraction can be suppressed. Therefore, it is possible to prevent the semiconductor substrate 1 of the solar battery cell 10 from being significantly warped, or the cells from being cracked or the electrodes being peeled off during the manufacturing process of the solar battery module. Therefore, a decrease in manufacturing yield can be prevented, and the thickness of the interconnector 7 can be increased, so that the resistance loss of the solar cell module can be reduced and the FF can be increased.
[0086] 又、上記の太陽電池モジュールは、インターコネクタ 7の相隣接する凹凸部 7h間に 平坦部 7kが挿入されて形成されているので、この平坦部 7kを集電電極 5, 6の上面 に接着することにより、インターコネクタ 7を集電電極 5, 6にしつ力り固定することがで き、さらに、インターコネクタ 7が集電電極 5, 6の強度を補強する役割を果たすので、 集電電極 5, 6の強度を増強することができる。又、インターコネクタ 7にこの平坦部 7k が存在することにより、真空吸着して搬送することが可能となり、太陽電池モジュール の生産性を向上することができる。  [0086] Further, in the above-mentioned solar cell module, a flat portion 7k is inserted between the concavo-convex portions 7h of the interconnector 7 adjacent to each other. By adhering to the collector, the interconnector 7 can be firmly fixed to the collecting electrodes 5 and 6, and the interconnector 7 serves to reinforce the strength of the collecting electrodes 5 and 6. The strength of the electrodes 5, 6 can be increased. In addition, the presence of the flat portion 7k in the interconnector 7 makes it possible to carry by vacuum suction and transfer, thereby improving the productivity of the solar cell module.
[0087] 又、上記の太陽電池モジュールでは、インターコネクタ 7の凹凸部 7hは、複数の突 起形状部 7iが相隣接する該突起形状部 7i間に直線形状部 7jを挿入して形成されて いるので、この直線形状部 7jを集電電極 5, 6の上面に接着することにより、上記の平 坦部 7kと同様、インターコネクタ 7を集電電極 5, 6にしつ力り固定することができ、さら に、インターコネクタ 7が集電電極 5, 6の強度を補強する役割を果たすので、集電電 極 5, 6の強度をさらに増強することができる。  [0087] In the above solar cell module, the uneven portion 7h of the interconnector 7 is formed by inserting a linear shape portion 7j between a plurality of projecting shape portions 7i adjacent to each other. Therefore, by bonding this linear portion 7j to the upper surfaces of the current collecting electrodes 5 and 6, the interconnector 7 can be fixedly fixed to the current collecting electrodes 5 and 6 in the same manner as the flat portion 7k. Further, since the interconnector 7 plays a role of reinforcing the strength of the current collecting electrodes 5 and 6, the strength of the current collecting electrodes 5 and 6 can be further enhanced.
[0088] 又、エッジ部 71は、平坦な形状であるので、この平坦な部分を用いて、インターコネ クタ 7を太陽電池セルの集電電極 5, 6にしつ力りと固着することができる。  Further, since the edge portion 71 has a flat shape, the interconnector 7 can be firmly fixed to the current collecting electrodes 5 and 6 of the solar cell using this flat portion. .
[0089] 又、上記の太陽電池モジュールでは、直線形状部 7jの長さ W2が、突起形状部 7i の底部の両裾部間の幅 W1よりも長くなるように直線形状部 7jが形成されているので 、凹凸部 7hの突起形状部 7iによる上述した半導体基板 1の反りを低減する効果を維 持しつつ、インターコネクタ 7を集電電極にしつ力り固定することができると共に、集電 電極 5, 6の強度を増強することができる。 Further, in the above-described solar cell module, the linear shape portion 7j is formed such that the length W2 of the linear shape portion 7j is longer than the width W1 between both bottom portions of the bottom of the projection shape portion 7i. Therefore, while maintaining the effect of reducing the warpage of the semiconductor substrate 1 due to the projections 7i of the projections and depressions 7h, the interconnector 7 can be firmly fixed to the current collecting electrode while the current collecting is performed. The strength of the electrodes 5 and 6 can be increased.
[0090] 又、上記の本実施の形態における太陽電池モジュールでは、インターコネクタ 7の セル間部 7cにストレスリリースが形成されている。従って、複数の太陽電池を配列す る際、或いは、配列した複数の太陽電池を透明な充填剤により透明基板と裏面カバ 一の間に封入する際等に、インターコネクタ 7が太陽電池セル 10のエッジを押さえつ けることによってインターコネクタ 7に生じる応力を逃がすことができる。そのため、イン ターコネクタ 7が太陽電池セル 10のエッジを押さえつけることによって発生するセル 割れ、力 4ナ等を大幅に低減することができる。又、熱膨張によりインターコネクタ 7の 伸びが大きくなつても、インターコネクタ 7が太陽電池セル 10の配列方向に伸縮する のを抑えることができる。そのため、太陽電池モジュールの製造過程で、太陽電池セ ル: LOの半導体基板 iに大きな反りが生じたり、セル割れや電極剥がれ等が発生した りするのを防止することができる。さらに、太陽電池モジュールが完成した後に、直射 日光等によってインターコネクタ 7が熱膨張しても、インターコネクタ 7が太陽電池セ ル 10の配列方向に伸縮するのを抑えることができる。同様に、表面の透明基板と裏 面カバーとの間の透明な充填材料の伸縮が起こっても、インターコネクタ 7が太陽電 池セル 10の配列方向に伸縮するのを抑えることができる。そのため、太陽電池モジュ ールの信頼性を高め、寿命を延ばすことができる。  Further, in the solar cell module according to the above-described embodiment, a stress release is formed in inter-cell portion 7 c of interconnector 7. Therefore, when arranging a plurality of solar cells, or when encapsulating the arranged plurality of solar cells between a transparent substrate and a back cover with a transparent filler, the interconnector 7 is connected to the solar cells 10. The stress generated in the interconnector 7 can be released by holding down the edge. Therefore, it is possible to greatly reduce cell cracking, force 4 and the like that occur when the interconnector 7 presses the edge of the solar cell 10. Further, even if the expansion of the interconnector 7 increases due to thermal expansion, expansion and contraction of the interconnector 7 in the direction in which the solar cells 10 are arranged can be suppressed. Therefore, in the manufacturing process of the solar cell module, it is possible to prevent the semiconductor substrate i of the solar cell: LO from causing a large warp, a cell crack, an electrode peeling, and the like. Furthermore, even after the completion of the solar cell module, even if the interconnector 7 thermally expands due to direct sunlight or the like, expansion and contraction of the interconnector 7 in the arrangement direction of the solar cell 10 can be suppressed. Similarly, even if the transparent filling material expands and contracts between the front transparent substrate and the back cover, expansion and contraction of the interconnector 7 in the arrangement direction of the solar cell 10 can be suppressed. Therefore, the reliability of the solar cell module can be improved and the life can be prolonged.
[0091] 又、上記の本実施の形態における太陽電池、又は、太陽電池モジュールでは、ィ ンターコネクタ 7のセル間部 7cには、ストレスリリースを形成している力 セル間部 7c の形状としてはこれには限られず、例えば、直線形状としてもよい。  [0091] In the solar cell or solar cell module according to the above-described embodiment, the inter-cell portion 7c of the inter-connector 7 has a shape of the force inter-cell portion 7c forming a stress release. The present invention is not limited to this, and may be, for example, a linear shape.
[0092] 本実施の形態では、上述したように、インターコネクタ 7の電極接触部 7a, 7bに、突 起形状部 7i及び直線形状部 7jで構成される凹凸部 7hと平坦部 7kとが形成されてい る。発明者は、このような構成案を導き出す過程で、さまざまな試行を行なっており、 次にこの試行内容について説明する。なお、この試行では、便宜上、本実施の形態 にかかる太陽電池及び太陽電池モジュールの各構成の符号を用いる。  [0092] In the present embodiment, as described above, the electrode contact portions 7a and 7b of the interconnector 7 are formed with the concavo-convex portions 7h and the flat portions 7k each including the protruding portions 7i and the linear portions 7j. It has been done. The inventor has performed various trials in the process of deriving such a configuration plan, and the details of the trials will be described next. In this trial, for convenience, reference numerals of the respective components of the solar cell and the solar cell module according to the present embodiment are used.
[0093] この試行内容は、一辺が 155mm程度の正方形状で、厚みが 0. 24mm程度の単 結晶シリコンや多結晶シリコン等の P型シリコン基板でなる半導体基板と、幅 2mmの インターコネクタとを用いて構成される太陽電池モジュールに関するものである。 [0094] この太陽電池モジュールに関し、前述した課題を解決するために、まず、試行 1とし て、インターコネクタ 7の厚さを 0. 3mmとし、インターコネクタ 7の電極接触部 7a, 7b に凹凸部 7hとして、ピークツーピークの高さが 0. 4mm、ピッチが 3. 5mmの連続し たサインカーブを形成した。このインターコネクタ 7を半導体基板 1に取り付けると、半 導体基板 1に反りが生じた。電極接触部 7a, 7bに形成された、ピークツーピークの高 さが 0. 4mm、ピッチが 3. 5mmの連続したサインカーブは、高さ 0. 4mmで底辺の 裾部間の幅が、 3. 5mmの頂部が丸みを帯びた三角波形に近い凸状波形とみなせ る。この凸状波形は、底辺の両裾部間の幅が高さの約 9倍近くあり、そのため、高さに 比べて底辺の両裾部間の幅が長すぎ、インターコネクタ 7にカ卩えられる熱によるインタ 一コネクタ 7の伸縮が、凹凸方向に沿っては生じにくぐ太陽電池セル 10の表面と平 行な方向には生じやすいと考えられる。そのため、試行 1では、半導体基板 1に反り が生じたと思われる。又、この試行 1では、電極接触部部 7a, 7bに連続したサイン力 ーブを形成したため、インターコネクタ 7と集電電極 5, 6との接着がピンポイントとなり 、接着が弱くなるという不具合も生じた。 [0093] In this trial, a semiconductor substrate made of a P-type silicon substrate such as monocrystalline silicon or polycrystalline silicon having a square shape of about 155 mm on a side and a thickness of about 0.24 mm and an interconnector having a width of 2 mm were used. The present invention relates to a solar cell module configured to be used. [0094] Regarding this solar cell module, in order to solve the above-mentioned problem, first, as a trial 1, the thickness of the interconnector 7 was set to 0.3 mm, and the electrode contact portions 7a and 7b of the interconnector 7 were provided with uneven portions. At 7h, a continuous sine curve with a peak-to-peak height of 0.4mm and a pitch of 3.5mm was formed. When the interconnector 7 was attached to the semiconductor substrate 1, the semiconductor substrate 1 was warped. The continuous sine curve with a peak-to-peak height of 0.4 mm and a pitch of 3.5 mm formed at the electrode contact parts 7a and 7b has a height of 0.4 mm and a width between the bottom skirts of 3 mm. The top of 5mm can be regarded as a convex waveform close to a rounded triangular waveform. In this convex waveform, the width between the bottom hem portions is about 9 times the height, so that the width between the bottom hem portions is too long compared to the height, and the width of the interconnector 7 is reduced. It is considered that the expansion and contraction of the interconnector 7 due to the generated heat is likely to occur in the direction parallel to the surface of the solar cell 10, which is difficult to occur in the uneven direction. Therefore, in trial 1, it is considered that the semiconductor substrate 1 was warped. Also, in this trial 1, since a continuous sine wave was formed at the electrode contact portions 7a and 7b, the adhesion between the interconnector 7 and the current collecting electrodes 5 and 6 became a pinpoint, and the adhesion was weakened. occured.
[0095] そこで、インターコネクタ 7の構成を、上述した本実施の形態の構成とした。この本 実施の形態ではインターコネクタ 7の厚さを 0. 3mmとしても、半導体基板 1に反りは 生じず、又、インターコネクタ 7と集電電極 5, 6との接着強度も確保することができた。 これは、上述した本実施の形態の構成では、突起形状部 7iの高さ Hが 0. 4mm,底 部の両裾部間の幅 W1は 1. 5mmであり、試行 1と異なり、突起形状部 7iの底部の両 裾部間の幅 W1は、高さ Hの約 4倍であり、インターコネクタ 7にカ卩えられる熱によるィ ンターコネクタ 7の伸縮力 凹凸方向に沿っては生じやすぐ太陽電池セル 1の表面 と平行な方向には生じにく 、からであると考えられる。  [0095] Therefore, the configuration of the interconnector 7 is the configuration of the present embodiment described above. In this embodiment, even if the thickness of the interconnector 7 is set to 0.3 mm, the semiconductor substrate 1 does not warp and the adhesive strength between the interconnector 7 and the current collecting electrodes 5 and 6 can be ensured. Was. This is because, in the configuration of the present embodiment described above, the height H of the projection 7i is 0.4 mm, and the width W1 between the bottoms of the bottom is 1.5 mm, which is different from the trial 1. The width W1 between the bottoms of the bottom of the part 7i is about four times the height H, and the expansion and contraction force of the interconnector 7 due to the heat generated by the interconnector 7 It is unlikely to occur in a direction parallel to the surface of the solar cell 1 and is considered to be due to the body.
[0096] この結果から、電極接触部 7a, 7bに形成する凹凸部 7hとしては、凸状波形の底辺 の両裾部間の幅の高さに対する倍率が低いほど効果的であるように見える。そこで、 次に、試行 2として、インターコネクタ 7の厚さを 0. 3mmとし、インターコネクタ 7の電 極接触部 7a, 7bに、本実施の形態の突起形状部 7iにおけるのと同様の形状で、高 さが 0. 4mm、底部の両裾部間の幅が 1. Ommの凸状波形を形成した。し力し、この 形成を、油圧プレスを用いて行なう際、成型されたインターコネクタ 7が型に引っ掛か つて卷回してしまい、そのままでは、太陽電池セル 10の集電電極 5, 6に接着すること ができな!/、と 、う不具合が発生した。 [0096] From these results, it can be seen that as the unevenness 7h formed in the electrode contact portions 7a and 7b, the lower the magnification of the width between the bottoms of the bottom of the convex waveform, the more effective it becomes. Then, as a second trial, the thickness of the interconnector 7 was set to 0.3 mm, and the electrode contact portions 7a and 7b of the interconnector 7 were formed with the same shape as that of the protrusion-shaped portion 7i of the present embodiment. A convex waveform having a height of 0.4 mm and a width between both bottom hem portions of 1.0 mm was formed. When this formation is performed using a hydraulic press, the molded interconnector 7 may be caught by the mold. Then, it could not be adhered to the current collecting electrodes 5 and 6 of the solar cell 10 as it was! /
[0097] そのため、太陽電池モジュールの生産性を考慮すると、試行 2のインターコネクタ 7 は採用しがたぐ上述した本実施の形態が優れていることが判明した。即ち、インター コネクタ 7の凹凸部 7hの突起形状部 7iは、この突起形状部 7iの底部の両裾部間の 幅が突起形状部 7iの高さの略 4倍となるように形成することで、太陽電池モジュール の製造過程における加熱冷却に際して、凹凸部 7hの突起形状部 7iの伸縮を、突起 方向に沿って効果的に生じさせることができる。従って、インターコネクタ 7が太陽電 池セル 10の表面と平行な方向に伸縮するのを効果的に抑えることができ、上述した 半導体基板 1の反りを効果的に低減することができるとともに、生産性が阻害されるの を防止することちできる。  [0097] Therefore, in consideration of the productivity of the solar cell module, it was found that the interconnector 7 of Trial 2 was excellent in the above-described embodiment, which was not easily adopted. That is, the projecting portion 7i of the uneven portion 7h of the interconnector 7 is formed such that the width between both bottoms of the bottom of the projecting portion 7i is approximately four times the height of the projecting portion 7i. In addition, at the time of heating and cooling in the manufacturing process of the solar cell module, the expansion and contraction of the projection-shaped portion 7i of the uneven portion 7h can be effectively caused along the projection direction. Therefore, the expansion and contraction of the interconnector 7 in the direction parallel to the surface of the solar cell 10 can be effectively suppressed, and the warpage of the semiconductor substrate 1 can be effectively reduced, and the productivity can be reduced. Can be prevented from being hindered.
[0098] 又、本実施の形態において、突起形状部 7iの頂部を、曲率半径 rが 0. 1mm程度 の円弧状としているのは、油圧プレスを用いて成型する際に、成型されたインターコ ネクタ 7が型に引っ掛力もないようにするのに効果的である力もである。  [0098] In the present embodiment, the top of the protruding portion 7i is formed in an arc shape having a radius of curvature r of about 0.1 mm because the molded interconnector is formed by using a hydraulic press. 7 is also a force that is effective in ensuring that the mold has no catching force.
[0099] 太陽電池モジュールのコスト削減の観点からは、インターコネクタ 7に形成される突 起形状部 7iの高さは低い方がよい。そこで、試行 3として、インターコネクタの厚さを 0 . 3mmとし、インターコネクタ 7の電極接触部 7a, 7bに、底部の両裾部間の幅は突起 形状部 7iの高さの略 4倍となるようにした状態で、高さを 0. 2mmとした突起形状部 7i を形成した。即ち、この突起形状部 7iは、高さが 0. 2mm,底部の両裾部間の幅が 0 . 75mmである。この状態では、多少反りが生じるものの、突起形状部 7iのピッチを 2 . 5mmとすることで、反りが生じるのを抑制することができる。  [0099] From the viewpoint of cost reduction of the solar cell module, the height of the protruding portion 7i formed in the interconnector 7 is preferably low. Therefore, in Trial 3, the thickness of the interconnector was set to 0.3 mm, and the width between the bottom hem portions of the electrode contact portions 7a and 7b of the interconnector 7 was approximately four times the height of the projection-shaped portion 7i. In this state, a projection 7i having a height of 0.2 mm was formed. That is, the protrusion 7i has a height of 0.2 mm and a width between both bottom hem portions of 0.75 mm. In this state, although warpage occurs somewhat, warpage can be suppressed by setting the pitch of the protruding portions 7i to 2.5 mm.
[0100] しかし、突起形状部 7iの高さを 0. 2mmよりも小さくすると、このような突起形状部 7i を形成したインターコネクタ 7を太陽電池セル 10の集電電極 5, 6に接着する際に、ィ ンターコネクタ 7の表面全体をノ、ンダで被覆して太陽電池セル 10の集電電極 5, 6に 接着すると、インターコネクタ 7の電極接触部 5, 6に形成された凹凸部 7hの突起形 状部 7iと集電電極 5, 6の表面との間で形成される空間にハンダが詰まってしまい、ィ ンターコネクタ 7の電極接触部 7a, 7bに凹凸部 7hを形成した効果が発揮できないと いう不具合が発生した。従って、太陽電池モジュールの生産性を考慮すると、インタ 一コネクタ 7の電極接触部 7a, 7bに形成された凹凸部 7hの突起形状部 7iの高さは、 0. 2mm以上とするのが望ましい。 [0100] However, if the height of the projection 7i is smaller than 0.2 mm, the interconnector 7 having the projection 7i formed thereon is bonded to the current collecting electrodes 5 and 6 of the solar battery cell 10. Then, when the entire surface of the interconnector 7 is covered with a solder and adhered to the current collecting electrodes 5 and 6 of the solar cell 10, the uneven portions 7 h formed on the electrode contact portions 5 and 6 of the interconnector 7 are formed. Solder clogged the space formed between the projection 7i and the surfaces of the current collecting electrodes 5 and 6, and the effect of forming the irregularities 7h on the electrode contact portions 7a and 7b of the interconnect connector 7 was exhibited. There was a problem that it was not possible. Therefore, considering the productivity of the solar cell module, The height of the protrusion 7i of the uneven portion 7h formed on the electrode contact portions 7a and 7b of one connector 7 is desirably 0.2 mm or more.
[0101] 即ち、上述した本実施の形態におけるインターコネクタ 7では、集電電極 5, 6とイン ターコネクタ 7との接着に際して、全体をノヽンダで被覆したインターコネクタ 7を用いて も、インターコネクタ 7に形成された凹凸部 7hの突起形状部 7iと集電電極 5, 6との間 に形成される空間を保持することができ、半導体基板 1の反りを低減する効果を十分 得ることができる。 [0101] That is, in the above-described interconnector 7 of the present embodiment, when the collector electrodes 5, 6 and the interconnector 7 are bonded to each other, the interconnector 7 that is entirely covered with a solder can be used. The space formed between the projection-shaped portion 7i of the uneven portion 7h formed on 7 and the collecting electrodes 5 and 6 can be maintained, and the effect of reducing the warpage of the semiconductor substrate 1 can be sufficiently obtained. .
[0102] なお、本発明は、その精神または主要な特徴力 逸脱することなぐ他のいろいろな 形で実施することができる。そのため、上述の実施の形態はあらゆる点で単なる例示 にすぎず、限定的に解釈してはならない。本発明の範囲は特許請求の範囲によって 示すものであって、明細書本文には、なんら拘束されない。さらに、特許請求の範囲 の均等範囲に属する変形や変更は、全て本発明の範囲内のものである。  [0102] The present invention can be embodied in other various forms without departing from the spirit or main characteristic power. Therefore, the above-described embodiment is merely an example in every aspect, and should not be interpreted in a limited manner. The scope of the present invention is defined by the appended claims, and is not restricted by the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.
[0103] また、この出願は、 2004年 4月 8日に日本で出願された特願 2004— 114684号お よび 2004年 9月 8日に日本で出願された特願 2004— 261194号に基づく優先権を 請求する。これに言及することにより、その全ての内容は本出願に組み込まれるもの である。  [0103] This application has priority over Japanese Patent Application No. 2004-114684 filed on April 8, 2004 and Japanese Patent Application No. 2004-261194 filed on September 8, 2004 in Japan. Claim rights. By reference to this, the entire contents are incorporated into the present application.
産業上の利用可能性  Industrial applicability
[0104] 本発明の太陽電池及び太陽電池モジュールは、抵抗損失の低減の為にインターコ ネクタの厚みを厚くしても、太陽電池や太陽電池モジュールの製造過程で、太陽電 池セルの半導体基板に大きな反りが生じたり、セル割れや電極剥がれ等が発生した りするのを防止し、製造歩留りの低下を防止するのに、有効に利用することができる。 [0104] The solar cell and the solar cell module of the present invention can be applied to the semiconductor substrate of the solar cell in the manufacturing process of the solar cell or the solar cell module even if the thickness of the interconnector is increased in order to reduce the resistance loss. It can be effectively used to prevent large warpage, cell cracking, electrode peeling, and the like, and to prevent a reduction in manufacturing yield.

Claims

請求の範囲 The scope of the claims
[1] 集電電極が形成された太陽電池セルを有し、前記太陽電池セルの前記集電電極 にインターコネクタが接続された太陽電池にお 、て、  [1] In a solar cell having a solar cell on which a current collecting electrode is formed, and an interconnector connected to the current collecting electrode of the solar cell,
前記インターコネクタに凹凸部が形成されていることを特徴とする太陽電池。  A solar cell, wherein an uneven portion is formed on the interconnector.
[2] 前記インターコネクタの、前記太陽電池セルの表面又は裏面に位置する部分の少 なくとも一部が、凹凸形状に形成されていることを特徴とする請求項 1記載の太陽電 池。  2. The solar cell according to claim 1, wherein at least a part of a part of the interconnector located on a front surface or a back surface of the solar cell is formed in an uneven shape.
[3] 前記インターコネクタの、前記太陽電池セルの表面に位置する部分の一部、又は、 前記太陽電池セルの裏面に位置する部分の一部のみが、凹凸形状に形成されてい ることを特徴とする請求項 1または 2に記載の太陽電池。  [3] The interconnector is characterized in that only a portion of a portion located on the front surface of the solar cell or only a portion of a portion located on the back surface of the solar cell is formed in an uneven shape. The solar cell according to claim 1 or 2, wherein
[4] 前記インターコネクタの、前記太陽電池セルのエッジ部分が平坦であり、その平坦 部を除く部分の当該インターコネクタの表側及び裏側に凹凸が形成されていることを 特徴とする請求項 1乃至 3のうちいずれ力 1つに記載の太陽電池。 [4] The edge portion of the solar cell of the interconnector is flat, and irregularities are formed on a front side and a back side of the interconnector except for the flat portion. The solar cell according to one of the three powers.
[5] 前記インターコネクタの凹凸が、波型形状であることを特徴とする請求項 1乃至 4の うちいずれか 1つに記載の太陽電池。 [5] The solar cell according to any one of claims 1 to 4, wherein the unevenness of the interconnector has a corrugated shape.
[6] 前記インターコネクタの凹凸力 アーチ型又は反アーチ型であることを特徴とする 請求項 1乃至 5のうちいずれか 1つに記載の太陽電池。 [6] The solar cell according to any one of claims 1 to 5, wherein the interconnector is of an arch type or an anti-arch type.
[7] 前記インターコネクタの凹凸が、部分的な突起型又は、部分的なへこみ型である ことを特徴とする請求項 1乃至 6のうちいずれか 1つに記載の太陽電池。 [7] The solar cell according to any one of claims 1 to 6, wherein the unevenness of the interconnector is a partial projection type or a partial depression type.
[8] 前記インターコネクタの凹凸のピッチ力 前記太陽電池セルの 1辺の長さ未満で、 凹凸の高さが 2mm以下であることを特徴とする請求項 1乃至 7のうちいずれか 1つに 記載の太陽電池。 [8] The unevenness pitch force of the interconnector is less than the length of one side of the solar cell, and the height of the unevenness is 2 mm or less. The solar cell as described.
[9] 前記インターコネクタに平坦部が形成され、前記凹凸部と前記平坦部とが交互に複 数回形成されて!ヽることを特徴とする請求項 1に記載の太陽電池。  [9] The solar cell according to claim 1, wherein a flat portion is formed in the interconnector, and the uneven portion and the flat portion are alternately formed a plurality of times.
[10] 前記インターコネクタの前記凹凸部は、頂部が丸みを帯びた 1個の突起でなる突起 形状部が単独で形成されてなり、又は、頂部が丸みを帯びた 1個の突起でなる突起 形状部が複数形成されるとともに、複数の前記突起形状部が相隣接する前記突起形 状部間に直線形状部を挿入して形成されてなることを特徴とする請求項 9に記載の 太陽電池。 [10] The uneven portion of the interconnector has a projection formed by a single projection with a rounded top, or a projection formed by a single projection with a rounded top. 10. The method according to claim 9, wherein a plurality of shape portions are formed, and the plurality of protrusion shape portions are formed by inserting a linear shape portion between the adjacent protrusion shape portions. Solar cells.
[11] 前記インターコネクタの前記凹凸部の前記直線形状部は、前記凹凸部の前記突起 形状部の底部の幅よりも長ぐ前記平坦部の長さよりも短く形成されていることを特徴 とする請求項 10に記載の太陽電池。  [11] The straight-shaped portion of the uneven portion of the interconnector is formed to be shorter than a length of the flat portion which is longer than a width of a bottom of the protruding portion of the uneven portion. The solar cell according to claim 10.
[12] 前記インターコネクタの前記凹凸部の前記突起形状部は、前記突起形状部の底部 の幅が前記突起形状部の高さの略 4倍となるように形成されて!ヽることを特徴とする 請求項 10または 11に記載の太陽電池。 [12] The projection-shaped portion of the uneven portion of the interconnector is formed such that the width of the bottom of the projection-shaped portion is approximately four times the height of the projection-shaped portion. The solar cell according to claim 10 or 11.
[13] 前記インターコネクタは、前記太陽電池セルの前記集電電極の両端部上面と接着 する部分が平坦となるように形成されていることを特徴とする請求項 9乃至 12のうち いずれか 1つに記載の太陽電池。 13. The interconnector according to claim 9, wherein the interconnector is formed such that portions that adhere to upper surfaces of both ends of the current collecting electrode of the solar cell become flat. The solar cell according to any one of the above.
[14] 請求項 1乃至 13のいずれか 1項に記載の太陽電池が複数設けられてなる太陽電 池モジュールであって、 [14] A solar cell module provided with a plurality of the solar cells according to any one of claims 1 to 13,
前記複数の太陽電池セルが配列されていると共に、互いに隣接する前記太陽電池 セルが前記インターコネクタによって接続されていることを特徴とする太陽電池モジュ 一ノレ。  The plurality of solar cells are arranged, and the adjacent solar cells are connected by the interconnector.
[15] 前記太陽電池セル及び前記インターコネクタが、透明基板と裏面カバーとの間に 挟まれて構成されていることを特徴とする請求項 14に記載の太陽電池モジュール。  15. The solar cell module according to claim 14, wherein the solar cell and the interconnector are sandwiched between a transparent substrate and a back cover.
[16] 前記インターコネクタの一部分であって、該インターコネクタにより接続された隣接 する前記太陽電池セル間となる部分が直線形状であることを特徴とする請求項 14ま たは 15に記載の太陽電池モジュール。  16. The solar cell according to claim 14, wherein a part of the interconnector and a portion between the adjacent solar cells connected by the interconnector has a linear shape. Battery module.
[17] 前記インターコネクタの一部分であって、該インターコネクタにより接続された隣接 する前記太陽電池セル間となる部分に、該インターコネクタにかかる種々のストレスを 緩和させるストレスリリースが形成されていることを特徴とする請求項 14乃至 16のうち いずれか 1つに記載の太陽電池モジュール。  [17] A stress release for relieving various stresses applied to the interconnector is formed in a portion of the interconnector between adjacent solar cells connected by the interconnector. The solar cell module according to any one of claims 14 to 16, wherein:
PCT/JP2005/005910 2004-04-08 2005-03-29 Solar battery and solar battery module WO2005098969A1 (en)

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