JP2013143529A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cracking of a pair of circuit boards 6, 7 by limiting concentration of pressure on the connections P, Q of the terminals of an FPC3 and external wiring 8, 9 when the circuit boards 6, 7 are pressed, even if the connections P, Q have a thickness.SOLUTION: A solar cell module 1 is configured by pressure holding an FPC3 mounting a solar cell 2 by means of a pair of circuit boards 6, 7 with fillers 4, 5 interposed therebetween. Connections P, Q formed by superposing external wiring 8, 9 on the terminals leading out the electrodes 3a, 3b of the FPC3 are located between the pair of circuit boards 6, 7. At least one of the pair of circuit boards 6, 7 is provided with a pressure adjustment part (e.g., recesses 7a, 7b) which adjusts the pressure applied to the connections P, Q when the pair of circuit boards 6, 7 are pressed so that the pressure applied to the connections P, Q approaches the pressure applied to the FPC3 at a part other than the connections P, Q.

Description

  The present invention relates to a solar cell module in which a wiring substrate on which solar cells are mounted is pressed and sandwiched between a pair of substrates via a filler.

  Solar cells that convert light energy into electrical energy have been attracting attention as a clean energy source with a low environmental load due to increased interest in global environmental problems. There are various types of materials used for solar cells, such as those using compound semiconductor materials and organic materials, but currently, materials using silicon crystals are the mainstream.

  A solar cell is rarely used alone as a single solar cell, and a plurality of solar cells connected in series or in parallel (solar cell string) are used as a pair of substrates so that a predetermined output can be obtained. It is used in the form of a solar cell module filled with a filler in between.

  FIG. 11 is a cross-sectional view showing a schematic configuration of a conventional solar cell module 100. As shown in the figure, the solar cell module 100 is a so-called laminating process in which a FPC (flexible printed circuit board) 102 on which solar cells 101 are mounted is pressed with a pair of substrates 105 and 106 via fillers 103 and 104. Is formed by. For simplification of description, in FIG. 11, the number of solar cells 101 and FPCs 102 held between the pair of substrates 105 and 106 is one.

FIG. 12A is a bottom view of the solar battery cell 101, and FIG. 12B is a plan view of the FPC 102. Note that the cross-sectional view of FIG. 11 is a cross-sectional view corresponding to the cross section taken along the line CC ′ of the FPC 102 of FIG. The solar battery cell 101 is composed of, for example, a back electrode type solar battery cell in which positive electrodes 101a and negative electrodes 101b are alternately arranged on the back surface (surface opposite to the light receiving surface) of a semiconductor substrate. Has been. In the FPC 102, electrodes 102a and 102b are formed in a pattern corresponding to the arrangement pattern of the electrodes 101a and 101b. The electrodes 102a and 102b are electrically connected to the electrodes 101a and 101b of the solar battery cell 101, respectively. The plurality of electrodes 102a is a strip of terminals 102 t ₁ are electrically connected, the plurality of electrodes 102b are electrically connected to the strip-like terminals 102 t _2. These terminals 102t ₁ · 102t _2, so that the plurality of electrodes 102a · 102b is withdrawn.

The terminals 102t ₁ and 102t ₂ are electrically connected to the external wirings 107 and 108, for example, by soldering. That is, the terminals 102 t ₁ and 102 t ₂ and the external wirings 107 and 108 are connected to overlap each other via the solder 109 and 110. In FIG. 12B, hatched portions indicate portions connected by the solders 109 and 110. With such a configuration, electric power generated in the solar battery cell 101 can be taken out via the FPC 102 and the external wirings 107 and 108.

  By the way, in the solar cell module 100 having the above-described configuration, there is a problem that cracks are easily generated in the pair of substrates 105 and 106 in the vicinity of the solder-mounted region at the time of laminating. The reason is as follows.

The FPC 102 is configured by, for example, a substrate (thickness 12.5 μm) made of polyimide (PI) with a copper foil layer (thickness 35 μm), and the FPC 102 at the portions of the terminals 102 t ₁ and 102 t ₂ . The thickness is about 50 μm. On the other hand, the external wirings 107 and 108 are configured by, for example, wire lines (thickness of 1 mm or more), bus bars (thickness of about 0.5 mm), and the like. Therefore, the connecting portion Q between the connecting part P, and terminals 102 t ₂ and the external circuit 108 between terminals 102 t ₁ and the external circuit 107, is thicker than other parts to increase.

  Therefore, in the pressurizing process of the laminating process, the pressure is concentrated in the region of the connecting portion P / Q where the thickness is increased, and the regions 105a, 106a facing the connecting portion P / Q in the substrates 105, 106 and Pressure concentrates in the regions 105b and 106b (see FIG. 11), and cracks are generated in these regions. In addition, when the board | substrates 105 * 106 are comprised with a thin board | substrate for the purpose of weight reduction of the solar cell module 100, since the intensity | strength of board | substrates 105 * 106 itself becomes still weaker, it becomes easy to produce a crack.

  In this regard, for example, in Patent Document 1, the lead wire for connecting the solar cell elements to each other and the output lead wire are thinner than a round hollow wire having a circular cross section or a round wire filled with contents. It is stated that the flat rectangular shape is more suitable for preventing element cracking in the laminating process at the time of module manufacture.

JP 2000-277784 A (refer to claim 2, paragraph [0013], FIG. 2 etc.)

  However, as described in Patent Document 1, there is a limit to thinning the wiring, and the wiring is thinned to the extent that pressure does not concentrate on the connection portion between the electrode terminal and the wiring (so that no step is generated in the connection portion). It is almost impossible to do. Therefore, even if the connection part has thickness, the structure which can suppress that a crack generate | occur | produces in a board | substrate in a lamination process is desired.

  The present invention has been made in order to solve the above-described problems. The purpose of the present invention is to provide a connection between the electrode terminal and the wiring even when the connection between the electrode terminal and the wiring has a thickness. An object of the present invention is to provide a solar cell module capable of suppressing the concentration of pressure and suppressing the generation of cracks in a substrate.

  In the solar cell module of the present invention, the wiring substrate on which the solar cells are mounted is pressed and sandwiched between the pair of substrates via the filler, and the external wiring overlaps the terminal from which the electrode of the wiring substrate is drawn. The connecting portion formed by the above is a solar cell module positioned between the pair of substrates, and at least one of the pair of substrates has a pressure applied to the connecting portion when the pair of substrates is pressurized. The pressure adjustment part which adjusts the pressure concerning the said connection part is provided so that the pressure concerning parts other than the said connection part in the said wiring board may be approached.

  According to said structure, when a pair of board | substrate is pressurized, the pressure concerning the connection part of an electrode terminal and external wiring is adjusted by the pressure adjustment part, and it approaches the pressure concerning parts other than a connection part in a wiring board. . As a result, even when the connection portion has a thickness, the pressure distribution between the pair of substrates can be made almost uniform between the connection portion and the portion other than the connection portion in the wiring board, and the connection portion and the pair of substrates are connected. It can suppress that a pressure concentrates on the site | part which opposes a part. As a result, the occurrence of cracks in the pair of substrates due to the pressure concentration can be suppressed.

  In the solar cell module of the present invention, the pressure adjusting portion may be a concave portion having a concave shape on the side facing the connection portion in at least one of the pair of substrates.

  In this configuration, when the pair of substrates is pressurized, the step between the terminal and the external wiring in the connection portion is canceled by the depression in the recess, and the pressure distribution between the pair of substrates is connected to the connection portion and the connection portion in the wiring substrate. It can be made almost uniform with other parts. Thereby, even when the connecting portion has a thickness, it is possible to reliably suppress partial concentration of pressure on the pair of substrates, and to reliably prevent cracks from occurring on the pair of substrates. Moreover, such an effect can be obtained with a simple configuration in which a recess is formed in the substrate.

  The solar cell module of this invention WHEREIN: The said recessed part may have the depth corresponded to the level | step difference of the said terminal and the said external wiring in the said connection part.

  In this case, when the pair of substrates is pressurized, the step between the terminal and the external wiring in the connection portion is surely canceled by the depression in the recess, and the pressure distribution between the pair of substrates is connected to the connection portion in the wiring substrate. It is possible to ensure that it is close to the uniform area.

  In the solar cell module of the present invention, the concave portion may be formed in a concave shape only on the surface facing the connection portion in at least one of the pair of substrates.

  In this configuration, the concave portion can be easily realized by molding or processing the substrate so that only the surface on the side facing the connection portion in at least one of the pair of substrates has a concave shape.

  The solar cell module of this invention WHEREIN: The said recessed part may be formed when the site | part which opposes the said connection part in at least one of the said pair of board | substrates is dented to the opposite side to the said connection part for every board | substrate.

  As described above, the concave portion as the pressure adjusting portion can also be realized when the portion of the substrate facing the connecting portion is recessed on the opposite side of the connecting portion together with the substrate.

  The solar cell module of this invention WHEREIN: The said recessed part may be formed in the taper shape from which an opening width becomes narrow as the distance with the said connection part increases.

  In this case, when the pair of substrates is pressurized, the change in pressure near the boundary between the inside and the outside of the recess in the substrate can be moderated. As a result, the pressure distribution between the pair of substrates can be made more uniform, and it is possible to more reliably suppress the occurrence of cracks due to partial concentration of pressure on the pair of substrates.

  The solar cell module of this invention WHEREIN: The resin substrate may be sufficient as the board | substrate with which the said recessed part is formed among a pair of said board | substrates.

  If it is a resin substrate, formation (processing) of a recessed part can be performed easily.

  In the solar cell module of the present invention, the pressure adjusting unit covers at least one of the pair of substrates from at least one portion facing the connecting portion, and covers the notched portion from the connecting portion side. Thus, it may be configured to have a stretchable sheet provided on the substrate having the cutout portion.

  In this configuration, even when the connecting portion has a thickness, when the pair of substrates are pressurized, the pressure applied to the connecting portion escapes to the stretchable sheet side, so that the pressure is partially applied to the pair of substrates. This can reduce the occurrence of cracks. In addition, since the stretchable sheet is provided on the substrate so as to cover the notch portion from the connection portion side, the filler does not leak outside from the notch portion, and the substrate, the stretchable sheet, and the wiring substrate Can be reliably laminated via the filler.

  In the solar cell module of the present invention, the wiring board is provided with a bypass diode for bypassing a current supplied from another wiring board via the external wiring, and the notch is formed of the pair of cutouts. In at least one of the substrates, a portion facing the connection portion and the bypass diode may be cut out.

  In this case, when the pair of substrates are pressurized, the pressure applied to the connecting portion and the bypass diode escapes to the stretchable sheet side, so that cracks in the pair of substrates can be suppressed and breakage of the bypass diode can be suppressed.

  In the solar cell module of the present invention, the solar cell may be a back electrode type solar cell in which a cell electrode is formed on the back surface of the semiconductor substrate opposite to the light receiving surface.

  In this case, the above-described effects can be obtained in the solar battery module in which the back electrode type solar battery cell is mounted.

  According to the present invention, the pressure applied to the connecting portion when the pair of substrates is pressurized is adjusted by the pressure adjusting portion, and the pressure distribution between the pair of substrates is different between the connecting portion and the portion other than the connecting portion in the wiring board. Almost uniform. As a result, even when the connection portion has a thickness, it is possible to suppress the pressure from being concentrated on the connection portion and the pair of substrates facing the connection portion, and to prevent the pair of substrates from being cracked.

It is sectional drawing which decomposes | disassembles and shows the schematic structure of the solar cell module which concerns on one Embodiment of this invention. It is a perspective view which shows the structure of the outline of the photovoltaic cell of the said solar cell module. It is a top view of the board | substrate located in FPC by which the said photovoltaic cell is mounted, and a back surface side. It is the top view of the said board | substrate, D-D 'arrow sectional drawing in the said top view, and E-E' arrow sectional drawing. It is sectional drawing which shows the other structure of the said board | substrate. It is sectional drawing which decomposes | disassembles and shows the structure of the outline of the solar cell module which concerns on other embodiment of this invention. It is a top view of the board | substrate located in FPC by which the photovoltaic cell of the said photovoltaic module is mounted, and a back surface side. It is the top view of the said board | substrate, D-D 'arrow sectional drawing in the said top view, and E-E' arrow sectional drawing. It is a top view of the board | substrate of FPC and the back surface in the other structure of the said solar cell module. It is the top view of the said board | substrate, D-D 'arrow sectional drawing in the said top view, and E-E' arrow sectional drawing. It is sectional drawing which shows the schematic structure of the conventional solar cell module. (A) is a bottom view of the solar cell of the solar cell module, and (b) is a plan view of the FPC on which the solar cell is mounted.

  Embodiments of the present invention will be described below with reference to the drawings. In each embodiment, the same components may be denoted by the same member numbers, and the description thereof may be omitted.

[Embodiment 1]
FIG. 1 is an exploded cross-sectional view showing a schematic configuration of a solar cell module 1 of the present embodiment. As shown in the figure, the solar cell module 1 is configured by pressing and sandwiching an FPC 3 on which solar cells 2 are mounted with a pair of substrates 6 and 7 through fillers 4 and 5. In this embodiment, one solar cell 2 is mounted on one FPC 3 and sealed between a pair of substrates 6 and 7. However, the number of solar cells 2 and FPCs 3 to be sealed is plural. May be.

  In this embodiment, the solar battery cell 2 is composed of a back electrode type solar battery cell. FIG. 2 is a perspective view showing a schematic configuration of the solar battery cell 2. The solar battery cell 2 is provided on the semiconductor substrate 20, the antireflection film 21 provided on the light receiving surface 20a of the semiconductor substrate 20, and the back surface (surface opposite to the light receiving surface 20a) 20b of the semiconductor substrate 20. A passivation layer 22, an n-electrode 23 (negative electrode) and a p-electrode 24 (positive electrode).

  The semiconductor substrate 20 is formed using, for example, an n-type single crystal silicon substrate, and has an n-type conductive region 20c, an n-type diffusion region 20d, and a p-type diffusion region 20e. The n-type diffusion region 20d is a region that is provided on the back surface 20b side of the semiconductor substrate 20 and has a higher concentration of n-type impurities than the n-type conductive region 20c. The p-type diffusion region 20e is a region that is provided on the back surface 20b side of the semiconductor substrate 20 and has p-type impurities.

  Here, two directions perpendicular to each other in a plane parallel to the back surface of the semiconductor substrate 20 are defined as an A direction and a B direction. The n-type diffusion region 20d and the p-type diffusion region 20e are formed to extend in a strip shape in the A direction and are alternately formed at a predetermined pitch in the B direction. In FIG. 2, two n-type diffusion regions 20d and two p-type diffusion regions 20e are shown. However, a large number (for example, several tens or more) of n-type diffusion regions 20d and p-type diffusion regions 20e are formed. May be.

  The n-electrode 23 is in ohmic contact with the n-type diffusion region 20 d through the opening 22 a of the passivation layer 22. Similarly, the p-electrode 24 is in ohmic contact with the p-type diffusion region 20 e through the opening 22 a of the passivation layer 22. Similarly to the n-type diffusion region 20d and the p-type diffusion region 20e, the n-electrode 23 and the p-electrode 24 are formed to extend in a band shape in the A direction and are alternately formed at a predetermined pitch in the B direction. .

  In the above configuration, when light (sunlight) is incident on the solar battery cell 2, excitons (electrons and holes) are generated, and electrons are collected on the n electrode 23 side and holes are collected on the p electrode 24 side. A potential difference is generated between the n electrode 23 and the p electrode 24. A current corresponding to this potential difference is taken out through the FPC 3 on which the solar battery cell 2 is mounted.

  The solar battery cell 2 is configured using an n-type silicon substrate as the semiconductor substrate 20, but may be configured using a p-type silicon substrate, or using a semiconductor substrate other than the silicon substrate. It may be configured.

  The FPC 3 is a flexible printed circuit board (wiring board) on which the solar cells 2 are mounted, and is composed of a base material made of polyimide (PI) with a copper foil layer. Here, FIG. 3 is a plan view of the FPC 3 and the substrate 7 on the back surface side. 1 is a cross-sectional view corresponding to the cross section taken along the line C-C ′ of the FPC 3 in FIG. 3.

As shown in FIG. 3, the FPC 3 includes a plurality of electrodes 3 a and 3 b formed in a pattern corresponding to the formation pattern of the p electrode 24 and the n electrode 23 of the solar battery cell 2. These electrodes 3a and 3b are formed in a line shape in the A direction, and are arranged in parallel and alternately in the B direction. A plurality of electrodes 3a is B direction are electrically connected at one end side of the formed terminals 3t ₁ and A direction in a strip, a plurality of electrodes 3b are terminals 3t ₂ formed in a strip shape in the direction B And the other end in the A direction are electrically connected. The plurality of electrodes 3a and 3b are drawn out by these terminals 3t ₁ and 3t ₂ . Furthermore, comb-shaped electrodes are formed of a plurality of electrodes 3a and the terminal 3t _1, a plurality of electrodes 3b and comb-shaped electrodes at the terminals 3t ₂ there is formed, these comb-shaped electrodes They are arranged to engage with each other.

The terminals 3t ₁ and 3t ₂ are electrically connected to the external wirings 8 and 9 by soldering. That is, the terminals 3t ₁ and 3t ₂ and the external wirings 8 and 9 are connected to each other via the solders 10 and 11. Incidentally, hatched portions in FIG. 3 indicate portions connected by the solders 10 and 11.

  Therefore, by connecting the p-electrode 24 and the n-electrode 23 of the solar battery cell 2 and the electrodes 3a and 3b of the FPC 3, respectively, the electric power generated in the solar battery cell 2 is supplied via the FPC 3 and the external wirings 8 and 9. It can be taken out (current can be passed through the external wirings 8 and 9).

In addition, in the connection part P between the terminal 3t ₁ and the external wiring 8, and the connection part Q between the terminal 3t ₂ and the external wiring 9, the external wirings 8 and 9 are overlapped and connected through the solders 10 and 11. , The thickness is larger than other parts (parts other than the connecting parts P and Q of the FPC 3). These connecting portions P and Q are located between the pair of substrates 6 and 7 and are sealed together with the solar cells 2 and the FPC 3 by the fillers 4 and 5 between the pair of substrates 6 and 7.

  In FIG. 1, among the fillers 4 and 5, the filler 4 positioned on the light incident side with respect to the solar battery cell 2 is formed of a transparent resin that transmits sunlight. Specifically, the filler 4 is selected from the group consisting of, for example, ethylene vinyl acetate resin, epoxy resin, acrylic resin, urethane resin, olefin resin, polyester resin, silicone resin, polystyrene resin, polycarbonate resin, and rubber-based resin. It is possible to use at least one transparent resin. In the present embodiment, the filler 5 positioned on the opposite side of the light incident side with respect to the solar battery cell 2 is formed of the same material as the filler 4 described above, but a material different from the filler 4 (for example, (Opaque or translucent resin).

  Of the pair of substrates 6 and 7, the substrate 6 (surface substrate) located on the light incident side with respect to the solar battery cell 2 is formed of a transparent glass substrate that transmits sunlight, but is polycarbonate (PC). It may be formed of a transparent resin substrate made of In this embodiment, the substrate 7 (back substrate) located on the opposite side of the light incident side with respect to the solar battery cell 2 is formed of a transparent resin substrate made of polycarbonate. In the substrate 7, concave portions 7a and 7b having concave shapes on the side facing the connection portions P and Q are formed at positions facing the connection portions P and Q. Thus, the point which provided the recessed part 7a * 7b in the board | substrate 7 is the big characteristic of this embodiment.

FIG. 4 shows a plan view of the substrate 7 (from the FPC 3 side), and a cross-sectional view taken along line DD ′ and a cross-sectional view taken along line EE ′ in the plan view. The concave portions 7a and 7b are formed so that when the solar battery cell 2 and the FPC 3 are pressed by the pair of substrates 6 and 7 via the fillers 4 and 5, the pressure applied to the connection portions P and Q is the connection portions P and Q in the FPC 3. It has a function as a pressure adjustment part which adjusts the pressure concerning connection part P * Q so that the pressure concerning other site | parts may be approached. The depth of the recess 7a is step L ₁ between the terminals 3t ₁ and the external circuit 8 at the connecting portion P is set to a depth D ₁ corresponding to _(see FIG. 1), the depth of the recess 7b, the connection portion The depth D ₂ corresponding to the step L ₂ between the terminal 3 t ₂ and the external wiring 9 at Q is set. Incidentally, the depth _D 1 · _{D 2} corresponding to the level difference _L 1 · _{L 2} is here, the depth _D 1 · _{D 2} means that almost identical with the step _L 1 · _{L 2.} Further, the recesses 7a and 7b are each formed in a tapered shape in which the opening width becomes narrower as the distance from the connection parts P and Q increases (as the distance from the connection parts P and Q increases).

  When the solar cell module 1 is obtained by laminating, the FPC 3 on which the solar cells 2 are mounted is pressurized with a pair of substrates 6 and 7 through the fillers 4 and 5. At this time, since the concave portions 7a and 7b are formed in the substrate 7 at positions facing the connection portions P and Q, respectively, when the solar cells 2 and the FPC 3 are pressurized with the pair of substrates 6 and 7, The pressure applied to the connecting portions P and Q is adjusted by the recesses 7a and 7b, respectively, and approaches the pressure applied to the portion other than the connecting portions P and Q in the FPC 3.

That is, when the pair of substrates 6 and 7 are pressurized, the stepped portions L ₁ and L ₂ of the connecting portions P and Q are canceled by the recesses (depths D ₁ and D ₂ ). -The pressure distribution between 7 becomes substantially uniform at the connection parts PQ in the FPC 3 and other parts. Therefore, even when the connection portions P and Q have a thickness, the connection portions P and Q and the pair of substrates 6 and 7 are prevented from concentrating pressure on the portions facing the connection portions P and Q, and the pair of substrates The generation of cracks at 6.7 can be suppressed.

In particular, by providing concave portions 7a and 7b whose surfaces facing the connection portions P and Q on the substrate 7 are provided as pressure adjusting portions, the steps L ₁ and L ₂ of the connection portions P and Q as described above. Can be canceled by the depression of the recess, and the pressure distribution between the pair of substrates 6 and 7 can be made substantially uniform. Thereby, even when the connecting portions P and Q have a thickness, it is possible to reliably suppress partial concentration of pressure on the pair of substrates 6 and 7 and to ensure that cracks are generated on the pair of substrates 6 and 7. Can be suppressed. Moreover, the above effect can be obtained with a simple configuration in which the recesses 7a and 7b are provided in the substrate 7.

Further, when the recess 7a-7b, since a level difference _L 1 depth corresponds to · _{L 2 D} 1 · _{D 2} at the connecting portion P, Q, pressurized the pair of substrates 6, 7, The steps L ₁ and L ₂ of the connecting portions P and Q are surely canceled by the recesses (depths D ₁ and D ₂ ), so that the pressure distribution between the pair of substrates 6 and 7 is reduced. Q and other parts can be made close to each other reliably.

It is desirable that D ₁ = L ₁ and D ₂ = L ₂ , but of course when D ₁ > L ₁ and D ₂ > L ₂ , D ₁ <L ₁ and D ₂ <L ₂ Even in this case, as long as the recesses 7a and 7b are formed, there is an effect of suppressing partial pressure concentration. That is, if D ₁ ≧ L ₁ and D ₂ ≧ L ₂ , the pressure distribution is made more uniform and cracks occur in the substrates 6 and 7 than in the case of D ₁ <L ₁ and D ₂ <L _2. Can be suppressed.

  Further, since the recesses 7a and 7b are formed in a taper shape, when the pair of substrates 6 and 7 are pressurized, the pressure changes in the vicinity of the boundary between the inside and the outside of the recesses 7a and 7b in the substrate 7 Can be relaxed. As a result, the pressure distribution in the vicinity of the connecting portions P and Q between the pair of substrates 6 and 7 can be made more uniform, and the pressure is partially concentrated on the pair of substrates 6 and 7 to cause cracks. Can be more reliably suppressed.

  Moreover, in this embodiment, the resin substrate is used as the board | substrate 7 in which recessed part 7a * 7b is formed among a pair of board | substrates 6 * 7. If the resin substrate is used in this way, the concave portions 7a and 7b can be easily formed by, for example, resin molding or processing using a mold, and the pressure adjusting portion can be easily realized.

  In this embodiment, as shown in FIG. 2, cell electrodes (n electrode 23 and p electrode 24) are formed on the back surface 20 b of the semiconductor substrate 20 opposite to the light receiving surface 20 a as the solar battery cell 2. In the solar cell module 1 in which such a solar cell 2 is mounted on the FPC 3, the above-described effect (effect of suppressing cracks on the substrates 6 and 7) can be obtained. it can.

  Further, the recesses 7a and 7b have a configuration in which only the surface of the substrate 7 facing the connection portions P and Q is formed in a concave shape. In this case, the concave portions 7a and 7b can be easily realized by molding or processing the substrate 7 so that only the surface of the substrate 7 facing the connection portions P and Q has a concave shape. However, the recesses 7a and 7b are not limited to such a configuration.

  FIG. 5 is a cross-sectional view showing another configuration of the substrate 7. As shown in the figure, the portions of the substrate 7 that face the connection portions P and Q may be formed by being recessed on the opposite side of the connection portions P and Q together with the substrate 7. That is, the front surface of the substrate 7 (on the connection portion P / Q side) may be concave, and the back surface of the substrate 7 may be convex. The substrate 7 having such a shape can be obtained by resin molding, for example.

  Thus, even when the recesses 7a and 7b are formed by recessing the entire substrate 7, the pressure applied to the connection portions P and Q when the pair of substrates 6 and 7 are pressurized is adjusted by the recesses 7a and 7b. The pressure applied to the parts other than the connecting portions P and Q of the FPC 3 can be approached. Therefore, the pressure adjusting portions (recesses 7a and 7b) can also be realized by forming the recesses 7a and 7b by recessing the substrate 7 itself.

  In the present embodiment, the recesses 7a and 7b are formed as pressure adjusting portions only on the back surface side substrate 7 of the pair of substrates 6 and 7, but the pressure adjusting portion is provided only on the front surface side substrate 6. A recess may be formed, and the above recess may be formed on both substrates. However, when forming a recess in the substrate 6, it is desirable to use a transparent resin substrate that can be easily processed as the substrate 6.

[Embodiment 2]
FIG. 6 is an exploded cross-sectional view showing a schematic configuration of the solar cell module 1 of the present embodiment, and FIG. 7 is a plan view of the FPC 3 and the substrate 7 of the solar cell module 1. 6 is a cross-sectional view corresponding to the cross section taken along the line CC ′ in the FPC 3 of FIG. Further, FIG. 8 shows a plan view of the substrate 7 (from the FPC 3 side) and a sectional view taken along the line DD ′ and an arrow EE ′ in the plan view. is there.

  As shown in these drawings, the solar cell module 1 of the present embodiment is formed by forming notches 31a and 31b in the substrate 7 instead of forming the recesses 7a and 7b in the configuration of the first embodiment. The elastic sheets 32a and 32b are provided at the positions of the notches 31a and 31b. In FIG. 7, the stretchable sheets 32a and 32b are not shown.

  The cutout portions 31a and 31b are formed by cutting out at least portions of the substrate 7 that face the connection portions P and Q. The notches 31a and 31b may be formed at the same time as the resin molding of the substrate 7, or may be formed by cutting a predetermined part after the substrate 7 is molded. In the present embodiment, the cutout portions 31a and 31b have a substantially rectangular shape in plan view. However, if the cutout portions 31a and 31b have a cutout shape including at least a portion opposed to the connection portions P and Q, the cutout portions 31a and 31b. The shape of may be any shape (for example, a polygon other than a circle or a rectangle in plan view).

  The elastic sheets 32a and 32b are provided on the substrate 7 having the cutout portions 31a and 31b so as to cover the cutout portions 31a and 31b from the connection portions P and Q side. The stretchable sheets 32a and 32b are made of a stretchable resin sheet such as polybutylene naphthalate (PBN) or polyethylene terephthalate (PET). The stretchable sheets 32a and 32b may have any size as long as they can cover the cutout portions 31a and 31b. Further, for example, the stretchable sheet may be constituted by a single sheet common to the stretchable sheets 32a and 32b, and may be provided so as to cover the entire substrate 7 including the cutout portions 31a and 31b.

  In the above configuration, when the pair of substrates 6 and 7 are pressed to perform laminating, the pressure applied to the connecting portions P and Q escapes to the elastic sheets 32a and 32b (by the expansion and contraction of the elastic sheets 32a and 32b). Even if the connecting parts P and Q have a thickness, the pressure concentration in the connecting parts P and Q is eliminated, and the pressure distribution is made uniform between the connecting parts P and Q in the FPC 3 and other parts. be able to. Thereby, it can suppress that a pressure concentrates partially on the site | part which opposes connection part P * Q in the board | substrates 6 * 7, and can suppress that a crack generate | occur | produces in the board | substrates 6 * 7.

  As described above, the pressure applied to the connecting portions P and Q when the substrates 6 and 7 are pressurized can be adjusted by the elastic sheets 32a and 32b, so that the pressure concentration in the connecting portions P and Q can be eliminated. 32a and 32b, and the notches 31a and 31b in which the stretchable sheets 32a and 32b are provided, as in the case of the recesses 7a and 7b of the first embodiment, are pressure adjusting portions that adjust the pressure applied to the connecting portions P and Q. Can be said to function as.

  Further, since the stretchable sheets 32a and 32b are provided on the substrate 7 so as to cover the notches 31a and 31b from the connection portions P and Q side, the notches are notched even when the filler 4 melts at the time of laminating. There is no leakage from the portions 31 a and 31 b to the outside, and the substrate 7 and the stretchable sheets 32 a and 32 b and the FPC 3 can be reliably stacked via the filler 4.

  9 is a plan view of the FPC 3 and the substrate 7 in another configuration of the solar cell module 1. FIG. 10 is a plan view of the substrate 7 (from the FPC 3 side) and DD in the plan view. The cross-sectional view taken along the line “arrow” and the cross-sectional view taken along the line EE ”are shown together. As shown in these drawings, the FPC 3 may be provided with a bypass diode 41 for bypassing a current supplied from another FPC 3 via the external wiring 9. The cutout portions 31 a and 31 b described above may be formed by cutting out portions of the substrate 7 that face the connection portions P and Q and the bypass diode 41.

  The bypass diode 41 is supplied from the other solar battery cell 2 and the FPC 3 through the external wiring 9 when the solar battery cell 2 does not generate power due to a malfunction such as a failure of the solar battery cell 2 or a shadow that blocks sunlight. The solar cell 2 is provided in parallel for the purpose of preventing a decrease in electric power (a decrease in power generation efficiency) and preventing thermal damage of the solar cell 2.

  Thus, when the bypass diode 41 is provided in FPC3, if the photovoltaic cell 2 and FPC3 are pressurized with a pair of board | substrates 6 * 7 via the fillers 4 * 5, the connection part P * Q and the bypass diode 41 will be shown. If the pressure is concentrated on the substrate 6 or 7, there is a risk that a crack will occur at the portion facing the substrate 6 or 7, and the bypass diode 41 may be damaged by the pressure concentration. However, the notches 31a and 31b are formed by notching portions of the substrate 7 facing the connecting portions P and Q and the bypass diode 41, and the elastic sheets 32a and 32b cover the notches 31a and 31b. Since the pressure applied to the connection parts P and Q and the bypass diode 41 escapes to the stretchable sheets 32a and 32b when the substrates 6 and 7 are pressurized, cracks in the substrates 6 and 7 occur. Can be suppressed, and damage to the bypass diode 41 can be suppressed.

  In this embodiment, the notches 31a and 31b and the stretchable sheets 32a and 32b are formed on the substrate 7. However, they may be formed on the substrate 6 or on both the substrates 6 and 7. May be.

  In this embodiment, an FPC with a copper foil layer is used as a wiring board, but a glass epoxy board with a copper foil layer (for example, FR4 (Flame Retardant Type 4)) may be used.

  In the solar cell module of the present invention, the wiring substrate on which the solar cells are mounted is pressed and sandwiched between the pair of substrates via the filler, and the external wiring overlaps the terminal from which the electrode of the wiring substrate is drawn. Can be used for a solar cell module in which the connecting portion formed between the pair of substrates is positioned between the pair of substrates.

DESCRIPTION OF SYMBOLS 1 Solar cell module 2 Solar cell 3 FPC (wiring board)
3a electrode 3b electrode 3t ₁ terminal 3t ₂ terminal 4 filler 5 filler 6 substrate 7 substrate 7a recess (pressure adjusting portion)
7b Concave part (pressure adjustment part)
8 External wiring 9 External wiring 20 Semiconductor substrate 20a Light receiving surface 20b Back surface 23 n electrode (cell electrode)
24 p-electrode (cell electrode)
31a Notch (pressure adjusting part)
31b Notch (pressure adjusting part)
32a Elastic sheet (pressure adjustment part)
32b Elastic sheet (pressure adjustment part)
41 Bypass diode P connection Q connection

Claims (10)

A wiring board on which a solar cell is mounted is pressed and sandwiched between a pair of substrates via a filler, and a connection portion formed by overlapping external wiring on a terminal from which an electrode of the wiring board is drawn out A solar cell module positioned between the pair of substrates,
At least one of the pair of substrates is connected to the connection portion so that a pressure applied to the connection portion when the pair of substrates is pressurized approaches a pressure applied to a portion other than the connection portion in the wiring board. A solar cell module comprising a pressure adjusting unit for adjusting the pressure.   2. The solar cell module according to claim 1, wherein the pressure adjusting portion is a concave portion having a concave shape on a side facing the connection portion in at least one of the pair of substrates.   The solar cell module according to claim 2, wherein the concave portion has a depth corresponding to a step between the terminal and the external wiring in the connection portion.   4. The solar cell module according to claim 2, wherein the concave portion is formed in a concave shape only on the surface facing the connection portion in at least one of the pair of substrates. 5.   4. The recess according to claim 2, wherein a portion of the at least one of the pair of substrates facing the connection portion is recessed with the substrate on the opposite side of the connection portion. The solar cell module described.   The solar cell module according to any one of claims 2 to 5, wherein the concave portion is formed in a tapered shape whose opening width becomes narrower as the distance to the connection portion increases.   The solar cell module according to any one of claims 2 to 6, wherein, of the pair of substrates, the substrate on which the concave portion is formed is a resin substrate. The pressure adjusting unit is
At least one of the pair of substrates, a notch portion at least cut out a portion facing the connection portion;
2. The solar cell module according to claim 1, comprising a stretchable sheet provided on a substrate having the cutout portion so as to cover the cutout portion from the connection portion side. . The wiring board is provided with a bypass diode for bypassing a current supplied from another wiring board via the external wiring,
9. The solar cell module according to claim 8, wherein the cutout portion is formed by cutting out a portion facing the connection portion and the bypass diode in at least one of the pair of substrates.   The solar cell according to any one of claims 1 to 9, wherein the solar cell is a back electrode type solar cell in which a cell electrode is formed on the back surface of the semiconductor substrate opposite to the light receiving surface. Battery module.

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