JP2013102027A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module having improved reliability.SOLUTION: A solar cell module 1 includes a solar cell 20 and a wiring material 33. The solar cell 20 includes first and second electrodes 21, 22. The wiring material 33 is electrically connected to the first electrode 21 of the solar cell 20. The wiring material 33 includes a wiring material body 33a and a plurality of connections 33b. The wiring material body 33a extends along one direction y. The connections 33b extend along a direction tilted relative to the one direction y, from the wiring material body 33a. The connections 33b are bonded to the solar cell 20. The connections 33b are electrically connected to the first electrode 21. Recessed parts 33a1, 33a2 are provided on both sides in the one direction of a part to which the connections of 33b of the wiring material body 33a are connected.

Description

  The present invention relates to a solar cell module.

  In recent years, attention has been focused on solar cell modules having a plurality of solar cells electrically connected by wiring materials as an energy source with a small environmental load. For example, Patent Document 1 describes an example thereof. The solar cell module described in Patent Document 1 has a plurality of solar cell strings. Each of the plurality of solar cell strings has a plurality of solar cells arranged along one direction and electrically connected by a wiring material. The plurality of solar cell strings are arranged along another direction perpendicular to the one direction. Solar cell strings adjacent in other directions are electrically connected by a wiring material. Thereby, the several solar cell contained in a solar cell module is electrically connected.

JP 2011-159646 A

  Usually, the thermal expansion coefficient of the wiring material is different from the thermal expansion coefficient of the solar cell. For this reason, when the temperature of the solar cell module changes, stress is generated between the solar cell and the wiring member. Due to this stress, the solar cell may be warped or the wiring material may be peeled off from the solar cell. Therefore, in a solar cell module, how to suppress a decrease in reliability due to a difference in thermal expansion coefficient between the solar cell and the wiring material has become a major issue.

  An object of the present invention is to provide a solar cell module having improved reliability.

  The solar cell module according to the present invention includes a solar cell and a wiring material. The solar cell has first and second electrodes. The wiring member is electrically connected to the first electrode of the solar cell. The wiring material has a wiring material main body and a plurality of connecting portions. The wiring material main body extends along one direction. The plurality of connecting portions extend from the wiring material body along a direction inclined with respect to one direction. The plurality of connecting portions are bonded to the solar cell. The plurality of connecting portions are electrically connected to the first electrode. Concave portions are provided on both sides in one direction of the portion where the connection portion of the wiring material body is connected.

  According to the present invention, it is possible to provide a solar cell module having improved reliability.

1 is a schematic cross-sectional view of a solar cell module according to an embodiment of the present invention. It is a schematic back view of a solar cell module according to an embodiment of the present invention. It is a schematic back view of the solar cell in one embodiment of the present invention. It is a schematic back view of a solar cell string in one embodiment of the present invention. FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. 4. FIG. 3 is a schematic rear view of a VI part in FIG. 2. It is a schematic back view of the VII part of FIG. It is a schematic back view of the solar cell in a modification.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described, and the ratio of the dimensions of the objects drawn in the drawings may be different from the ratio of the dimensions of the actual objects. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

  As shown in FIGS. 1 and 2, the solar cell module 1 includes a plurality of solar cell strings 10. Specifically, the solar cell module 1 includes first to sixth solar cell strings 10a to 10f. As shown in FIG. 1, the plurality of solar cell strings 10 are arranged between a first protection member 11 located on the light receiving surface side and a second protection member 12 located on the back surface side. A filler layer 13 is provided between the first protective member 11 and the second protective member 12. The plurality of solar cell strings 10 are sealed with the filler layer 13.

  The 1st protection member 11 can be comprised by the member which has translucency, such as a glass substrate and a resin substrate, for example. The second protective member 12 can be constituted by, for example, a resin sheet, a resin sheet with a metal foil interposed therebetween, a glass substrate, a resin substrate, or the like. The filler layer 13 can be made of, for example, a resin such as ethylene / vinyl acetate copolymer (EVA), polyvinyl butyral (PVB), polyethylene (PE), polyurethane (PU), or the like.

  Each of the plurality of solar cell strings 10 includes a plurality of solar cells 20 arranged along the x-axis direction. As shown in FIGS. 1 and 3, the solar cell 20 has first and second main surfaces 20a and 20b. Solar cell 20 receives light mainly on first main surface 20a. For this reason, the 1st main surface 20a may be called a light-receiving surface, and the 2nd main surface 20b may be called a back surface. Solar cell 20 may be a solar cell that can generate power only when light is received at first main surface 20a constituting the light receiving surface, or at any of first and second main surfaces 20a, 20b. A double-sided light-receiving solar cell that can generate power even when receiving light may be used.

  The kind of solar cell 20 is not particularly limited. The solar cell 20 can be constituted by, for example, a crystalline silicon solar cell using a crystalline silicon substrate.

  As shown in FIG. 3, the solar cell 20 is a back junction type solar cell having electrodes 21 and 22 on the second main surface 20b side. Specifically, the solar cell 20 includes a photoelectric conversion unit 23 and electrodes 21 and 22 disposed on the main surface on the back surface side of the photoelectric conversion unit 23. One of the electrodes 21 and 22 is an electrode that collects holes, and the other is an electrode that collects electrons.

  The shape of each of the electrodes 21 and 22 is not particularly limited. In the present embodiment, each of the electrodes 21 and 22 has a comb-like shape. The electrode 21 and the electrode 22 are arranged so as to be inserted into each other. Specifically, each of the electrodes 21 and 22 has a plurality of finger portions 21a and 22a and bus bar portions 21b and 22b. Each of the plurality of finger portions 21a and 22a extends along the x-axis direction. The plurality of finger portions 21a and 22a are arranged at intervals from each other along the y-axis direction perpendicular to the x-axis direction.

  The plurality of finger portions 21a are electrically connected to the bus bar portion 21b. The bus bar portion 21b is arranged on one side (x1 side) in the x-axis direction of the plurality of finger portions 21a. The bus bar portion 21 b is provided from the one side end portion in the y axis direction to the other side end portion in the x1 side end portion in the x axis direction of the solar cell 20.

  Similarly, the plurality of finger portions 22a are electrically connected to the bus bar portion 22b. The bus bar portion 22b is arranged on the other side (x2 side) in the x-axis direction of the plurality of finger portions 22a. The bus bar portion 22b is provided from the one side end portion in the y axis direction to the other side end portion in the x2 side end portion in the x axis direction of the solar cell 20.

  As shown in FIG. 2, in each of the plurality of solar cell strings 10, the plurality of solar cells 20 are electrically connected by a first wiring member 31. Specifically, as shown in FIGS. 4 and 5, the first wiring member 31 includes an electrode 21 of one solar cell 20 and an electrode 22 of the other solar cell adjacent to each other in the x-axis direction. Are electrically connected. The first wiring member 31 and the second main surface 20b of the solar cell 20 are bonded by an adhesive layer 40 shown in FIG. The adhesive layer 40 can be composed of, for example, a cured product of solder or resin adhesive. The first wiring member 31 can be composed of, for example, a metal foil such as Ag or Cu, a laminated body of metal foil, a metal foil whose surface is covered with solder or the like.

  The first to sixth solar cell strings 10 a to 10 f are electrically connected by the second wiring member 32. Specifically, the solar cell 20A located on the most x2 side of the first solar cell string 10a, the solar cell 20B located on the most x2 side of the second solar cell string 10b, and the third solar cell string 10c Solar cell 20C located on the most x2 side and solar cell 20D located on the most x2 side of the fourth solar cell string 10d, and solar cell 20E located on the most x2 side of the fifth solar cell string 10e and the sixth The solar cell 20F located on the most x2 side of the solar cell string 10f is electrically connected by the second wiring member 32, respectively. More specifically, the electrodes 22 of the solar cells 20A, 20C, and 20E are electrically connected to the electrodes 22 of the solar cells 20B, 20D, and 20F by the second wiring member 32, respectively.

  Further, the solar cell 20H located on the most x1 side of the second solar cell string 10b, the solar cell 20I located on the most x1 side of the third solar cell string 10c, and the most x1 of the fourth solar cell string 10d. The solar cell 20J located on the side and the solar cell 20K located closest to the x1 side of the fifth solar cell string 10e are also electrically connected by the second wiring member 32, respectively. More specifically, the electrodes 21 of the solar cells 20H and 20J are electrically connected to the electrodes 21 of the solar cells 20I and 20K by the second wiring member 32, respectively. A first lead electrode 41 is provided on each of the second wiring member 32 electrically connected to the solar cells 20H and 20I and the second wiring member 32 electrically connected to the solar cells 20J and 20K. Are electrically connected.

  A third wiring member 33 is electrically connected to the electrode 21 of the solar cell 20G located closest to the x1 side of the first solar cell string 10a. The solar cell 20G and the third wiring member 33 are bonded by the adhesive layer 40. Similarly, the third wiring member 33 is also electrically connected to the electrode 21 of the solar cell 20L located closest to the x1 side of the sixth solar cell string 10f. The solar cell 20L and the third wiring member 33 are bonded by the adhesive layer 40.

  The second lead electrode 42 is electrically connected to each of the third wiring member 33 electrically connected to the solar cell 20G and the third wiring member 33 electrically connected to the solar cell 20L. Connected. The electric power generated in the solar cell module 1 is extracted by the second extraction electrode 42 and the first extraction electrode 41.

  As described above, the second wiring member 32 includes the electrode 21 with the one solar cell 20 and the electrode 21 of the other solar cell 20 adjacent to the one solar cell 20 in the y-axis direction (one direction). The electrode 22 is electrically connected.

  The second wiring member 32 has a wiring member main body 32a and a plurality of connecting portions. The wiring material main body 32a extends along the y-axis direction (one direction). The wiring material main body 32 a is not bonded to the solar cell 20 and is not directly electrically connected to the solar cell 20. The plurality of connection parts include a plurality of first connection parts 32b and a plurality of second connection parts 32c.

  Each of the plurality of first connection portions 32b extends from one side portion (y1 side portion) in the y-axis direction of the wiring material main body 32a along a direction inclined with respect to the y-axis direction. Specifically, each of the plurality of first connection portions 32b extends from one side portion (y1 side portion) in the y-axis direction of the wiring material body 32a along the x-axis direction perpendicular to the y-axis direction. It extends. Each of the plurality of first connection portions 32b is bonded to the solar cells 20A, 20C, 20E, 20H, and 20J by the adhesive layer 40. Each of the plurality of first connection portions 32b is directly electrically connected to the electrodes 22 of the solar cells 20A, 20C, and 20E or the electrodes 22 of the solar cells 20H and 20J.

  In the present invention, “tilt” includes vertical.

  Each of the plurality of second connection portions 32c extends from the other side portion (y2 side portion) in the y-axis direction of the wiring material body 32a along a direction inclined with respect to the y-axis direction. Specifically, each of the plurality of second connection portions 32c extends along the x-axis direction perpendicular to the y-axis direction from the other side portion (y2-side portion) of the wiring material body 32a in the y-axis direction. It extends. The plurality of second connection portions 32c are arranged at intervals from each other along the x-axis direction. Each of the plurality of second connection portions 32c is bonded to the solar cells 20B, 20D, 20F, 20I, and 20K by the adhesive layer 40. Each of the plurality of second connection portions 32c is directly electrically connected to the electrodes 21 of the solar cells 20B, 20D, 20F, 20I, and 20K.

  The third wiring member 33 includes a wiring member main body 33a and a plurality of connection portions 33b. The wiring material body 33a extends along the y-axis direction (one direction). Each of the plurality of connecting portions 33b extends from the wiring member body 33a along a direction inclined with respect to the y-axis direction. Specifically, each of the plurality of connecting portions 33b extends from the wiring member body 33a along the x-axis direction perpendicular to the y-axis direction. The wiring material body 33a is not bonded to the solar cell 20 and is not directly electrically connected to the solar cell 20. Each of the plurality of connection portions 33b is bonded to the solar cells 20G and 20L by the adhesive layer 40. Each of the plurality of connecting portions 33b is directly electrically connected to the electrodes 21 of the solar cells 20G and 20L.

  In the second and third wiring members 32 and 33, concave portions 32a1 and 32a2 are provided on both sides in the y-axis direction (one direction) of the portion where the connection portions 32b, 32c and 33b of the wiring member main bodies 32a and 33a are connected. , 33a1 and 33a2 are provided.

  6 and 7, the depth D and the width W1 may be the same or different in the recesses 32a1, 32a2, 33a1, and 33a2.

  By the way, for example, when the temperature of the solar cell module 1 is increased, the solar cell 20 and the wiring members 31 to 33 are thermally expanded. Here, the thermal expansion coefficients of the solar cell 20 and the wiring members 31 to 33 are different from each other. Therefore, the solar cell 20 and the wiring members 31 to 33 have different thermal expansion amounts. As a result, stress is generated between the wiring members 31 to 33 and the solar cell 20. Due to this stress, the solar cell 20 may be warped or the wiring members 31 to 33 may be peeled off.

  Here, in the present embodiment, in the second and third wiring members 32 and 33, the portions of the wiring member main bodies 32a and 33a where the connecting portions 32b, 32c and 33b are connected in the y-axis direction (one direction). Concave portions 32a1, 32a2, 33a1, and 33a2 are provided on both sides. For this reason, when the wiring members 32 and 33 are thermally expanded larger than the solar cell 20, relatively thin portions provided with the recesses 32a1, 32a2, 33a1 and 33a2 of the wiring member main bodies 32a and 33a are easily expanded and contracted. Further, the wiring material bodies 32a and 33a can be easily bent and deformed starting from the portions where the recesses 32a1, 32a2, 33a1 and 33a2 are provided. Therefore, the stress applied to the wiring members 32 and 33 and the solar cell 20 when the temperature of the solar cell module 1 changes can be suppressed. Accordingly, warpage of the solar cell 20 and peeling of the wiring materials 32 and 33 from the solar cell 20 can be suppressed. As a result, improved reliability can be realized.

  From the viewpoint of realizing improved reliability, the ratio of the depth D of the recesses 32a1, 32a2, 33a1, 33a2 in the x-axis direction to the width W0 of the wiring material bodies 32a, 33a in the x-axis direction (D / W0) Is preferably 1/3 or more, and more preferably 1/2 or more. However, if the ratio (D / W0) is too large, the electrical resistivity of the wiring material bodies 32a and 33a may become too high, or the strength of the wiring material bodies 32a and 33a may become too low. Therefore, (D / W0) is preferably 2/3 or less, and more preferably 1/2 or less.

  Further, from the viewpoint of realizing improved reliability, the ratio of the width W1 of the recesses 32a1, 32a2, 33a1, 33a2 in the y-axis direction to the width W0 of the wiring material bodies 32a, 33a in the x-axis direction (W1 / W0 ) Is preferably 1/20 or more. However, if the ratio (W1 / W0) is too large, the electrical resistivity of the wiring material bodies 32a and 33a may become too high, or the strength of the wiring material bodies 32a and 33a may become too low. Therefore, the ratio (W1 / W0) is preferably 1/6 or less, and more preferably 1/10 or less.

(Modification)
In the above embodiment, the example in which the bus bar portions 21b and 22b are each provided in a straight line having a uniform width has been described. On the other hand, in this modification, as shown in FIG. 8, each of the bus bar portions 21b and 22b has a relatively thick portion and a relatively thin portion. The bus bar portions 21b and 22b are electrically connected to the wiring members 31 to 33 at relatively thick portions. That is, in the bus bar portions 21b and 22b, the portions connected to the wiring members 31 to 33 are relatively thick, and the other portions are relatively thin. By doing in this way, while being able to connect electrically the wiring materials 31-33 and the solar cell 20 reliably, the loss | disappearance by recombination of a carrier can be suppressed, and the improved photoelectric conversion efficiency can be obtained.

  The present invention includes various embodiments not described herein. For example, the solar cell does not necessarily have to be a back junction type solar cell having first and second electrodes on one main surface, and has a first electrode on one main surface and a second electrode on the other main surface. It may be a solar cell having these electrodes.

  Each of the first and second electrodes may not be a bus bar portion but may be a bus bar-less electrode constituted by a plurality of finger portions.

  The wiring member may connect the first electrode of one solar cell of adjacent solar cells and the first electrode of another solar cell, or one of the adjacent solar cells. The second electrode of the battery may be connected to the second electrode of another solar cell, or the first electrode of one solar cell and the second of the other solar cells among the adjacent solar cells. May be connected to the other electrode.

  The solar cell module may include only one solar cell.

  As described above, the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Solar cell module 10, 10a-10f ... Solar cell string 11 ... 1st protection member 12 ... 2nd protection member 13 ... Filler material layer 20, 20A-20L ... Solar cell 20a ... 1st main surface 20b ... 2nd main surface 21, 22 ... Electrode 21a, 22a ... Finger part 21b, 22b ... Busbar part 23 ... Photoelectric conversion part 31-33 ... Wiring material 32a, 33a ... Wiring material main body 32a1, 32a2, 33a1, 33a2 ... Recessed part 32b 32c, 33b ... connection 40 ... adhesive layer

Claims (4)

A solar cell having first and second electrodes;
A wiring material electrically connected to the first electrode of the solar cell;
With
The wiring material is
A wiring material body extending along one direction;
A plurality of connecting portions extending from the wiring member body along a direction inclined with respect to the one direction, bonded to the solar cell, and electrically connected to the first electrode;
Have
The solar cell module in which the recessed part is provided in the both sides in the said one direction of the part to which the said connection part of the said wiring material main body was connected. The solar cell module according to claim 1,
A plurality of solar cells,
The wiring member electrically connects the first electrode of one solar cell and the first or second electrode of another solar cell adjacent to the one solar cell in the one direction. And
The plurality of connecting portions are:
The wiring member body extends from one side portion in the one direction along the direction inclined with respect to the one direction, and is bonded to the one solar cell and the first of the one solar cell. A plurality of first connections electrically connected to the electrodes;
The wiring member body extends from the other side portion in the one direction along the direction inclined with respect to the one direction, and is bonded to the other solar cell and the first or the other solar cell. A plurality of second connecting portions electrically connected to the second electrode;
Including
The concave portion is provided on both sides in the one direction of a portion where the plurality of first and second connection portions of the wiring member main body are connected. The solar cell module according to claim 1 or 2,
Ratio of the depth of the recess in the other direction to the width of the wiring material body in the other direction perpendicular to the one direction ((depth of the recess in the other direction) / (in the other direction) The width of the wiring material body)) is 1/3 to 2/3. It is a solar cell module as described in any one of Claims 1-3,
Ratio of the width of the recess in the one direction to the width of the wiring material body in the other direction perpendicular to the one direction ((width of the recess in one direction) / (wiring material in the other direction) The width of the main body)) is 1/20 to 1/6.

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