JPWO2016199501A1 - Wiring sheet - Google Patents

Abstract

A wiring sheet including wiring for electrically connecting back electrode type solar cells, wherein the wiring includes a first wiring and a second wiring which are electrically insulated, and the first wiring and The second wiring includes a plurality of first wiring line shape portions and a plurality of second wiring line shape portions extending in a first direction, respectively, and the plurality of first wiring line shape portions and the plurality of second wiring lines. There is provided a wiring sheet in which an opening is formed inside a wiring line region formed of a shape portion.

Description

  The present invention relates to a wiring sheet.

  Patent Document 1 (Japanese Patent Laid-Open No. 2011-151262) is known as a solar battery using a back electrode type solar battery cell.

  Patent Document 1 includes a first conductivity type electrode and a second conductivity type electrode formed on one surface side of a semiconductor substrate, and the first conductivity type electrode on one surface side of the semiconductor substrate. And a back electrode type solar battery cell having at least four alignment marks and a wiring for electrically connecting the back electrode type solar battery cell to a region other than where the electrode for the second conductivity type is formed. A solar cell comprising a wiring sheet having a plurality of same-shaped parts having the same shape and at least two different-shaped parts lacking a part of the same-shaped part is described. ing.

JP 2011-151262 A

  Currently, further improvement in the power generation efficiency of solar cells is desired. In a solar battery composed of a back electrode type solar battery cell and a wiring sheet, an alignment technique suitable for further improving power generation efficiency has not been proposed.

  Further, when the back electrode type solar cell and the wiring sheet are overlapped, the back electrode type solar cell and the wiring sheet are temporarily fixed via an ultraviolet curable resin. The wiring sheet is provided with an opening for irradiating the ultraviolet curable resin with ultraviolet rays from the wiring sheet side. Normally, as shown in FIG. 19, the opening 30 is disposed outside the comb-shaped wiring portion on the wiring sheet. If the position of the opening changes, the amount of ultraviolet light irradiated to the ultraviolet curable resin changes, so that the ultraviolet curable resin is not sufficiently cured, or conversely, the ultraviolet curable resin is overcured. . If the ultraviolet curable resin is not sufficiently cured, a short circuit failure due to misalignment of the back electrode type solar cells tends to occur. Further, when the ultraviolet curable resin is overcured, the back electrode type solar cell is cracked or chipped. Thus, by changing the position of the opening, the production yield of the back electrode solar cell with wiring sheet is likely to be reduced. Therefore, the position of the opening cannot be freely moved and is limited. Therefore, in order to improve the luminous efficiency of the solar cell, the position of the opening of the wiring sheet can be moved even when the length of the cell electrode is increased or the cell area of the solar cell is increased. In addition, since the wiring portion cannot be arranged in a region outside the opening, there is a problem that current collection loss occurs in this region.

  Therefore, the present invention has been made in view of the above problems, and is a wiring sheet provided with wiring for electrically connecting back electrode type solar cells, and can improve current collection efficiency. An object is to provide a simple wiring sheet.

  The present invention is a wiring sheet comprising wiring for electrically connecting back electrode type solar cells, wherein the wiring includes a first wiring and a second wiring that are electrically insulated, Each of the first wiring and the second wiring includes a plurality of first wiring line shape portions and a plurality of second wiring line shape portions extending in the first direction, and the plurality of first wiring line shape portions and the plurality of second wiring line shape portions. It is a wiring sheet in which an opening is formed inside a wiring line region composed of a second wiring line shape portion.

  According to the present invention, it is possible to provide a wiring sheet capable of improving current collection efficiency.

FIG. 3 is a schematic plan view of an example of the solar cell according to Embodiment 1 viewed from the light receiving surface side. It is the schematic which shows the arrangement | positioning relationship between the back surface electrode type photovoltaic cell and wiring sheet in Embodiment 1. FIG. FIG. 3 is a schematic cross-sectional view along III-III in FIG. 2. 4 is a schematic plan view of an example of the back surface of the back electrode type solar battery cell in Embodiment 1. FIG. It is an enlarged view of the part shown by V of FIG. It is an enlarged view of the part shown by VI of FIG. FIG. 3 is a schematic plan view of an example of a wiring pattern on the wiring sheet according to the first embodiment. FIG. 8 is an enlarged view of a portion indicated by XV in FIG. 7. It is the typical top view which looked at an example of the photovoltaic cell with a wiring sheet in Embodiment 1 from the back surface side. FIG. 10 is an enlarged view of a portion indicated by XI in FIG. 9. FIG. 3 is a schematic cross-sectional view illustrating an example of a method for manufacturing a solar cell in the first embodiment. It is a schematic diagram which shows the structure of the opening part of the wiring sheet in Embodiment 2, and is an enlarged view of the part shown by VIII of FIG. It is a schematic diagram which shows the structure of the opening part of the wiring sheet of the back electrode type solar cell with a wiring sheet in Embodiment 2, and is an enlarged view of the part shown by X of FIG. 6 is a schematic diagram showing a structure of an opening portion of a wiring sheet in Embodiment 3. FIG. 6 is a schematic diagram showing a structure of an opening of a wiring sheet in Embodiment 4. FIG. FIG. 10 is a schematic diagram showing a structure in the vicinity of an opening of a wiring sheet of a back electrode solar cell with wiring sheet in a fourth embodiment. FIG. 10 is a schematic diagram showing a structure of an opening of a wiring sheet in a fifth embodiment. FIG. 10 is a schematic diagram showing a structure in the vicinity of an opening of a wiring sheet of a back electrode type solar cell with a wiring sheet in a fifth embodiment. It is a plane schematic diagram of an example of the conventional wiring sheet.

  Embodiments of the present invention will be described below with reference to the drawings. In these drawings, the same reference numerals represent the same or corresponding parts. In the following, a single or a plurality of solar cells are arranged in a row direction on a wiring sheet provided with a cell arrangement portion (region on the wiring sheet corresponding to one solar cell) for arranging solar cells. A description will be given of a configuration arranged in a matrix in the column direction. In addition, in this specification, when it only describes as a "solar cell", the photovoltaic cell with a wiring sheet comprised from a photovoltaic cell and a wiring sheet also uses the sealing material for the photovoltaic cell with a wiring sheet. It is also an expression including a sealed solar cell module.

<Embodiment 1>
(Solar cell with wiring sheet)
In FIG. 1, the typical top view which looked at the solar cell (solar cell with a wiring sheet) using the wiring sheet of Embodiment 1 from the light-receiving surface side is shown. Here, the wiring sheet is a configuration in which a cell arrangement portion for arranging solar cells is formed by providing the wiring 16 on one surface side of the insulating base material 11. The back electrode type solar cell 20 is electrically connected by the wiring 16 on the surface of the insulating base material 11. In addition, the outer peripheral shape of the back electrode type solar cell 20 is, for example, as shown in FIG. 4 described later when a wafer (single crystal semiconductor substrate) cut from a single crystal ingot having a substantially circular cross section is used. Two sets of two substantially parallel sides obtained by excising a part of a circle are provided, and the corner portion (corner portion) connecting them is an arc shape having a part of the circumference. Further, this outer peripheral shape is substantially rectangular when a wafer (polycrystalline semiconductor substrate) cut from a polycrystalline ingot having a substantially rectangular cross section is used.

  In the solar cell 100 shown in FIG. 1 configured as described above, a plurality of back electrode type solar cells 20 are connected in series in the row direction on the surface of the insulating substrate 11 of the wiring sheet. An example in which a plurality of string strings are arranged in the column direction and the ends of the solar cell string strings are connected to each other so that the energization path is meandered in series so as to meander.

  The arrangement relationship between the back electrode type solar cell and the wiring sheet is shown in FIG. FIG. 2 corresponds to a part of the row of solar cells 100 shown in FIG. As shown in FIG. 2, the wiring 16 of the wiring sheet 10 is used to connect the first wiring 12 for connection of the first conductivity type electrode of the solar battery cell and the second conductivity type electrode of the solar battery cell. The second wiring 13 is a wiring line shape portion that is a portion corresponding to the comb teeth of the comb-shaped first wiring 12 and a wiring that is a portion corresponding to the comb teeth of the comb-shaped second wiring 13. The first wiring 12 and the second wiring 13 are arranged so that the line-shaped portions are alternately meshed one by one. As a result, the wiring line shape part of the first wiring 12 and the wiring line shape part of the second wiring 13 are alternately arranged one by one at a predetermined interval.

  Moreover, the 1st wiring 12 and the 2nd wiring 13 are also provided with the wiring connection part which connects a some wiring line shape part. In the solar cell 100 shown in FIG. 1, the wiring line shape part of one first wiring 12 and the wiring line shape part of the other second wiring 13 are connected between the cell arrangement parts adjacent to each other in the row direction. Between the cell arrangement part at the end of the column L1 and the cell arrangement part at the end of the column L2 that are adjacent to each other in the row direction surrounded by the broken line in FIG. The wiring line shape part of one first wiring 12 and the distribution line shape part of the other second wiring 13 are electrically connected via the wiring connection part.

  And on the surface of the insulating base material 11 of the wiring sheet 10, the cell arrangement | positioning part 19 which is a combination of the 1st wiring 12 and the 2nd wiring 13 is arranged in the surface of the insulating base material 11. FIG. Here, FIG. 2 shows a part of the solar cell shown in FIG. 1 and is constituted by three cell arrangement portions 19, but is not limited to this, and is surrounded by a broken line in FIG. 1. As shown in the part, the cell arrangement part 19 may be electrically connected to another cell arrangement part 19 arranged adjacent to the surface of the insulating substrate 11 in the column direction.

  And the solar cell with a wiring sheet shown in FIG. 1 can be produced by installing the back electrode type solar battery cell 20 on the surface of the wiring sheet 10 having the configuration shown in FIG.

  FIG. 3 shows a schematic cross-sectional view along III-III in FIG. The back electrode type solar cell 20 shown in FIG. 3 includes a semiconductor substrate 21 such as a silicon substrate having n-type or p-type conductivity, and a semiconductor substrate 21 serving as a light receiving surface of the back electrode type solar cell 20. It has an antireflection film 27 formed on the concavo-convex surface on one surface side, and a passivation film 26 formed on the back surface of the semiconductor substrate 21 serving as the back surface of the back electrode type solar battery cell 20.

  Also, on one surface side of the semiconductor substrate 21, a first conductivity type impurity region 22 formed by diffusing the first conductivity type impurity and a second conductivity type impurity formed by diffusing the second conductivity type impurity. The regions 23 are alternately formed at predetermined intervals, and first conductivity type electrodes that contact the first conductivity type impurity regions 22 through contact holes provided in the passivation film 26 on the back surface of the semiconductor substrate 21 are formed. A first conductivity type electrode line 24 and a second conductivity type electrode line 25 constituting a second conductivity type electrode in contact with the second conductivity type impurity region 23 are provided. As the first conductivity type impurity and the second conductivity type impurity, phosphorus or the like can be used when the conductivity type is n type, and boron or the like can be used when the conductivity type is p type.

  Here, on one surface side of the semiconductor substrate 21, a plurality of pn junctions are formed at the interface between the first conductivity type impurity region 22 or the second conductivity type impurity region 23 and the inside of the semiconductor substrate 21. .

  In the first embodiment, at least part of the surface of the first conductivity type electrode line 24 and / or at least part of the surface of the second conductivity type electrode line 25 of the back electrode type solar battery cell 20 is, for example, At least one selected from the group consisting of nickel (Ni), gold (Au), platinum (Pt), palladium (Pd), silver (Ag), tin (Sn), SnPb solder, and ITO (Indium Tin Oxide) An electrically conductive material containing may be provided. In this case, the wiring of the wiring sheet 10 and the electrode of the back electrode type solar battery cell 20 (first conductivity type electrode constituted by a plurality of first conductivity type electrode lines 24, a plurality of second conductivity type electrodes). There is a tendency that the electrical connection with the second conductivity type electrode constituted by the line 25 is made favorable, and the weather resistance of the electrode of the back electrode type solar cell 20 can be improved.

  As the semiconductor substrate 21, for example, a silicon substrate made of polycrystalline silicon or single crystal silicon having n-type or p-type conductivity can be used.

  As the first conductivity type electrode and the second conductivity type electrode, for example, an electrode made of a metal such as silver can be used.

  As the passivation film 26, for example, a silicon oxide film, a silicon nitride film, or a stacked body of a silicon oxide film and a silicon nitride film can be used.

  As the antireflection film 27, for example, a silicon oxide film, a silicon nitride film, or a stacked body of a silicon oxide film and a silicon nitride film can be used.

  In the configuration shown in FIGS. 2 and 3, both ends are arranged such that one end of the wiring sheet 10 in one cell arrangement portion becomes a wiring line shape portion of the first wiring 12 and the other end becomes a wiring line shape portion of the second wiring 13. However, it is also possible to make the conductivity types (polarities) of the wiring line shape portions at both ends the same. Similarly, in the configuration shown in FIG. 3, one end of one back electrode type solar cell 20 becomes the first conductivity type electrode line 24, and the other end becomes the second conductivity type electrode line 25. Although the conductivity types (polarities) are different, the conductivity types (polarities) of the electrode lines at both ends may be the same.

  It should be noted that the concept of the back electrode type solar cell has only a configuration in which both the first conductivity type electrode and the second conductivity type electrode are formed only on one surface (back surface) of the semiconductor substrate 21 described above. In addition, a so-called back-contact solar cell (a solar cell having a light receiving surface), such as an MWT (Metal Wrap Through) cell (a solar cell having a configuration in which a part of an electrode is disposed in a through-hole provided in a semiconductor substrate) All of the solar cells having a structure in which current is extracted from the back surface on the opposite side are included.

  And the 1st conductivity type electrode line 24 which comprises the 1st conductivity type electrode of the said back surface electrode type photovoltaic cell 20 and the 2nd conductivity type electrode line 25 which comprises the 2nd conductivity type electrode are respectively a figure. As shown in FIG. 1, the solar cell 100 is manufactured in FIG. 1 by being electrically connected to a cell placement portion that is a combination of one first wiring 12 and one second wiring 13 of the wiring sheet 10. become.

  In the above solar cell, in order to achieve good connection between the electrode pattern of the back electrode type solar cell and the wiring pattern provided on the wiring sheet, alignment accuracy between the electrode pattern and the wiring pattern is required. Is required to be high. In the present embodiment, a predetermined mark is provided on the back electrode type solar cell for the above alignment accuracy. In the present embodiment, the mark can be recognized by, for example, a transmission image or a reflection image using the observation device 15 provided in the direction of the arrow A in FIG. 3 or the direction of the arrow B in FIG. It can be used for alignment between the back electrode type solar cell 20 and the wiring sheet 10. In addition, what is necessary is just to use the observation apparatus 15 which used the infrared sensor (infrared camera), for example, in order to recognize the part which the mark of the back electrode type photovoltaic cell and the wiring of the wiring sheet overlapped. By forming the marks so that they can be recognized in this way, the alignment accuracy can be maintained. An example of a mark and alignment using the mark will be described below.

(Marks and electrode patterns in back electrode type solar cells)
FIG. 4 shows a schematic plan view of an example of the back surface of the back electrode type solar battery cell in the first embodiment. 4 corresponds to the back surface of one of the solar cells 20 shown in FIG. 1, and is a schematic plan view seen from the direction of arrow A in FIG.

  In FIG. 4, the first conductivity type electrode is formed so as to arrange a plurality of first conductivity type electrode lines 24, and the second conductivity type electrode includes a plurality of second conductivity type electrode lines 25. The first conductivity type electrode lines 24 and the second conductivity type electrode lines 25 are alternately arranged. In FIG. 4, the first conductivity type electrode line 24 and the second conductivity type electrode line 25 extend in the y-axis direction. 5 and 6 are enlarged views of portions indicated by V and VI in FIG. 4, respectively.

  Six marks a, b, c, d, e, and f are provided in the back electrode type solar cell 20 in the first embodiment, and at least a part of the plurality of marks a, b, c, d, e, and f is provided. Is preferably formed on the impurity region of the back electrode type solar battery cell 20. When the mark formed of the electrode material on the impurity region is in contact with the wiring as will be described later, the mark functions as an electrode, so that the power generation efficiency of the cell can be maintained well.

  In the electrode lines 24 and 25 in the back electrode type solar cell 20 in the first embodiment, electrode line shape portions 24a and 25a extending in the first direction (y-axis direction in FIG. 4), and the electrode line shape portions What is comprised from electrode extension part 24b, 25b provided on the extension line in the 1st direction of electrode line shape part 24a, 25a so that it may isolate | separate from 24a, 25a is contained. The marks a, b, c, d, e, and f are the regions between the electrode line-shaped portions 24a and 25a and the electrode extension portions 24b and 25b and the regions adjacent to the regions where no electrode is present. It is provided at least in part. Thus, by providing the electrode extension portions 24b and 25b on the cell end side with respect to the marks a, b, c, d, e, and f, the end portions than the marks a, b, c, d, e, and f are provided. The cell region on the side can also function as a power generation region, and the power generated in that region can be taken out, so that power generation efficiency can be improved.

  In the first embodiment, one solar cell has four first conductivity type marks a, b, d, e for alignment of the first conductivity type electrode, and the second conductivity type electrode. It includes a total of six marks including two second conductivity type marks c and f for alignment. Further, in one solar battery cell, it can be expressed that three marks a, b, and c are provided in the vicinity of the corner portion A, and three marks d, e, and f are provided in the vicinity of the corner portion D. .

  It is desirable that these marks have an arrangement or shape that does not have a point-symmetrical position or shape with respect to the center of the electrode pattern in the same plane when considering the shape and arrangement of the electrodes on the back surface of the cell and the mark. In other words, it is desirable that the mark does not have rotational symmetry. Here, rotational symmetry means a property that overlaps the original figure when a certain figure is rotated at a certain rotation angle. By adopting such an arrangement or shape, in the process of placing solar cells on the wiring sheet, when the solar cells rotate in the same plane, the mark cannot be observed or the shape of the mark to be observed is Since it is different from other observed shapes, an error in the arrangement of the cells becomes clear, and it is possible to prevent alignment with the wiring sheet in an incorrect state.

  The said mark can be formed with the material similar to the electrode material used in order to form an electrode pattern. By forming the mark with the same material as the electrode material, the mark can be applied simultaneously with the electrode pattern. For example, when forming the mark by a process different from the formation of the electrode pattern using another material. In comparison, the mark can be accurately manufactured at a desired position. As described above, a mark for alignment with the wiring pattern formed on the wiring sheet is formed on one surface side of the solar battery cell.

  The shape of the mark may be an elliptical shape extending in the length direction of the electrode lines 24 and 25 as shown in FIGS. 4 to 6, or may be a circle, a triangle, or a rectangle. Further, the mark may include a plurality of marks having different shapes. Especially, it is preferable that the mark has an elliptical shape extending in the length direction of the electrode lines 24 and 25. For example, in electrode formation by screen printing, a printed pattern may be lost depending on the conditions and environment during printing. In the case where the defect is a scum that occurs at the beginning or end of squeegeeing, the tip shape of the electrode pattern may be similar to a circle. In particular, if the tip shape of the electrode pattern is circular and the mark is also circular, the circle shape at the tip of the electrode pattern is erroneously recognized as a mark, resulting in extremely poor alignment recognition accuracy and incorrect alignment. It becomes easy to do. By making the shape of the alignment mark an elliptical shape having a certain length and directivity, an effect of reducing erroneous recognition can be obtained.

  In the first embodiment, each electrode line has a solid line shape in which electrode materials are continuously formed, but the electrode material can also be a dotted line or broken line electrode line formed in a dot shape or the like, When a dot electrode is employed, it is preferable that at least one of the shape and size of the dot electrode and the mark is different so that the mark can be identified.

  In the first embodiment, the width of the electrode line shape portion (length in the x-axis direction in FIG. 4) is 50 to 200 μm, the interval between the electrode line shape portions is 300 to 1000 μm, and the mark size (in the case of a circle) In the case of an ellipse, the major axis or the minor axis is preferred, and in the case of a polygon, the length or height of one side is preferably 100 to 10,000 μm, but other sizes can also be used.

(Wiring pattern including alignment area in wiring sheet)
In FIG. 7, the plane schematic diagram of an example of the wiring sheet in Embodiment 1 is shown. FIG. 7 shows a state of the wiring pattern as viewed from the wiring arrangement side, showing a wiring pattern corresponding to one cell arrangement portion in FIG. 1, and a schematic plan view seen from the direction of arrow B in FIG. FIG. FIG. 8 is an enlarged view of a portion indicated by XV in FIG.

  The wiring sheet of the first embodiment includes wiring for electrically connecting the back electrode type solar cells, and such wiring corresponds to the electrode pattern of the back electrode type solar cells. Use a wiring pattern. As shown in FIG. 7, the wiring sheet has an opening formed inside a wiring line region 123 including a plurality of first wiring line shape portions 12 a and a plurality of second wiring line shape portions 13 a. Specifically, in the wiring of the first embodiment, a plurality of wiring line shape portions 12a and 13a extending in the first direction (y-axis direction in FIG. 7) are alternately provided. At least a part of each of the wiring line shape portions 12a and 13a is branched to include branch portions 12a ', 12a' ', 13a', and 13a ''.

  The branch portion 12a ′ of the first wiring line shape portion extends on the extension of the first wiring line shape portion 12a closest to the first wiring line shape portion 12a including the branch portion, and the branch portion 12a ″ is It extends on the extension of the first wiring line shape portion 12a that is second closest to the first wiring line shape portion 12a including the branch portion. Both the branch portions 12a 'and 12a' 'branch to the same direction side with respect to the first wiring line shape portion 12a including the branch portion. The first wiring line shape part 12a including the branch part and the branch parts 12a 'and 12a' 'are electrically connected by the arc-shaped first connection pattern 12c. In addition, the 1st connection pattern 12c is defined as what is contained in the 1st wiring line shape part 12a containing a branch part.

  The branch portion 13a ′ of the second wiring line shape portion extends on the extension of the second wiring line shape portion 13a closest to the second wiring line shape portion 13a including the branch portion, and the branch portion 13a ″ is It extends on the extension of the second wiring line shape portion 13a that is second closest to the second wiring line shape portion 13a including the branch portion. Both the branch portions 13a 'and 13a' 'branch to the same direction side with respect to the second wiring line shape portion 13a including the branch portion. The second wiring line shape portion 13a including the branch portion and the branch portions 13a 'and 13a' 'are electrically connected by the arc-shaped second connection pattern 13c. In addition, the 2nd connection pattern 13c is defined as what is contained in the 2nd wiring line shape part 13a containing a branch part.

  The first wiring line shape portion 12a including the branch portion and the branch portion 13a '' of the second wiring line shape portion are adjacent to each other with the insulating portion interposed therebetween, and the second wiring line shape portion 13a including the branch portion and the first wiring The branch portion 12a '' of the line-shaped portion is adjacent to the insulating portion with the insulating portion interposed therebetween. The first wiring line shape portion 12a including the branch portion, the branch portions 12a ′ and 12a ″ and the first connection pattern 12c, the second wiring line shape portion 13a including the branch portion, the branch portions 13a ′ and 13a ″ and the first connection pattern 12c. No wiring pattern exists in the portion surrounded by the two connection patterns 13c, that is, the portion surrounded by the first wiring line shape portion including the branch portion and the second wiring line shape portion including the branch portion, and the insulating base An opening in which the material is exposed is formed.

  In the first embodiment, there are two branch portions included in the first wiring line shape portion and two branch portions included in the second wiring line shape portion. However, if the opening portion can be formed, the branch portion The number of is not particularly limited. Moreover, the wiring pattern which connects a wiring line shape part and a branch part is not limited to arc shape, It can also be made into a straight line.

  In the wiring sheet shown in FIG. 7, the wiring includes a first wiring 12 and a second wiring 13 that are electrically insulated. The first wiring 12 includes a first wiring connection portion 12b that connects the first wiring line shape portions 12a. The second wiring 13 includes a second wiring connection portion 13b that connects the second wiring line shape portions 13a. In the wiring sheet of the first embodiment, the first wiring line shape portion 12a is connected to the first conductivity type electrode line 24 of the back electrode type solar cell, and the second wiring line shape portion 13a is for the second conductivity type. Connect to electrode line 25. The branch portion 12a 'of the first wiring line shape portion is connected to the first conductivity type electrode line 24b, and the branch portion 13a' of the second wiring line shape portion is connected to the second conductivity type electrode line 25a. Further, the branch portion 12 a ″ of the first wiring line shape portion is connected to the first conductivity type electrode line 24, and the branch portion 13 a ″ of the second wiring line shape portion is connected to the second conductivity type electrode line 25. To do.

  When the wiring sheet 10 and the back electrode type solar battery cell 20 are aligned and overlapped, the wiring sheet 10 is turned over relative to the back electrode type solar battery cell 20. In consideration of this, in FIG. 7, each of the four corner portions of the cell arrangement portion corresponds to each of the four corner portions A, B, C, D of the back electrode type solar cell 20 shown in FIG. A, B, C, and D are attached.

  The insulating base material can be used without particular limitation as long as it is an electrically insulating material. For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide ( A material containing at least one resin selected from the group consisting of PPS (polyphenylene sulfide), polyvinyl fluoride (PVF), and polyimide can be used.

  The thickness of the insulating substrate is not particularly limited, and can be, for example, 10 μm or more and 200 μm or less. Note that the insulating substrate may have a single-layer structure consisting of only one layer or a multi-layer structure consisting of two or more layers.

  The material of the first wiring 12 and the second wiring 13 can be used without particular limitation as long as it is made of an electrically conductive material. For example, a metal containing at least one selected from the group consisting of copper, aluminum, and silver can be used.

  Further, the thicknesses of the first wiring 12 and the second wiring 13 are not particularly limited, and can be, for example, 5 μm or more and 75 μm or less.

  As for the shapes of the first wiring 12 and the second wiring 13, at least a part of the first wiring line shape portion 12a and the second wiring line shape portion 13a branches, and the first wiring line shape portion and the branch portion including the branch portion. Needless to say, the opening is surrounded by the second wiring line shape portion including, and is not limited to the shape described above, and can be set as appropriate.

  For example, nickel (Ni), gold (Au), platinum (Pt), palladium (Pd), silver (on the surface of at least a part of the first wiring 12 and / or at least a part of the surface of the second wiring 13 is used. You may install the electroconductive substance containing at least 1 sort (s) selected from the group which consists of Ag), tin (Sn), SnPb solder, and ITO (Indium Tin Oxide). In this case, the electrical connection between the first wiring 12 and the second wiring 13 and the electrode of the back electrode type solar battery cell is improved, and the weather resistance of the first wiring 12 and / or the second wiring 13 is improved. It tends to be able to be made.

  At least a part of the surface of the first wiring 12 and / or at least a part of the surface of the second wiring 13 may be subjected to a surface treatment such as a blackening treatment.

  Each of the first wiring 12 and the second wiring 13 may have a single-layer structure composed of only one layer, or may have a multi-layer structure composed of two or more layers.

  Below, an example of the manufacturing method of a wiring sheet is demonstrated. First, a translucent insulating base material such as a PET film is prepared, and an electrically conductive material such as a metal foil or a metal plate is bonded to the entire surface of one surface of the insulating base material.

  Next, a part of the electrically conductive material bonded to the surface of the insulating base material is removed by photo-etching or the like to pattern the electrically conductive material, thereby patterning the electric material patterned on the surface of the insulating base material. A wiring material composed of the first wiring 12 and the second wiring 13 made of a conductive material is formed. As described above, a wiring sheet having a wiring pattern having the configuration shown in FIG. 7 can be produced.

  In the first embodiment, the wiring line shape portion has a solid line shape in which wiring materials are continuously formed.

  In the first embodiment, the width of the wiring line shape portion (the length in the x-axis direction in FIG. 7) is preferably 100 to 900 μm, and the interval between the wiring line shape portions is preferably 300 to 1000 μm. It can also be a size.

  In the above description, the alignment region near the corner portion A has been described. However, the alignment region near the corner portion D can also have the same structure.

(Alignment of back electrode type solar cells and wiring sheet)
FIG. 9 shows a schematic plan view of an example of the solar cell in the first embodiment. 9 shows the back electrode type solar battery cell 20 shown in FIG. 4 and the cell arrangement part of the wiring sheet 10 shown in FIG. 7 with the back electrode type so that the corner parts A, B, C, D coincide with each other. It shows a state in which it is aligned and overlapped so as to be turned upside down relative to the solar battery cell 20, and for the wiring sheet 10, only the wiring pattern is shown by a broken line. FIG. 10 is an enlarged view of the alignment region peripheral portion XI including the three marks a, b, and c shown in FIG.

  A wiring pattern in which an opening surrounded by a back electrode type solar cell having the mark (FIG. 4), a first wiring line shape portion including a branch portion, and a second wiring line shape portion including a branch portion is formed. As shown in FIGS. 9 and 10, the wiring sheet (FIG. 7) having the mark has a mark “a”, “b”, “c” of the back electrode type solar cell overlapped with the opening near the corner portion A of the wiring sheet. In the first embodiment, the marks d, e, and f of the back electrode type solar cell are overlapped with the opening in the vicinity of the corner portion D of the wiring sheet. Thus, the back electrode type solar cell and the wiring sheet have marks a, b, c, and c provided on the back electrode type solar cell from an opening (hereinafter also referred to as an alignment region) where there is no wiring on the wiring sheet. They are superimposed so that d, e, and f can be recognized.

  In such a configuration, when the solar cells are arranged one by one on the wiring sheet, the back electrode type solar cell is observed while observing the portion including the alignment region of the wiring sheet from the direction of arrow A in FIG. The solar cells are aligned so that at least part of the marks provided on the battery cells can be recognized through the alignment region of the wiring sheet. For example, the back electrode type solar cell is observed through the alignment region of the wiring sheet as shown in FIGS. 9 and 10 by observing from the position corresponding to the direction of the arrow A in FIG. It is arranged so that the marks a, b, c, d, e, f on the back side of are recognized. In the corner portion A, the marks a, b, and c are overlaid on the alignment region that is the opening of the wiring sheet. At the same time, in the corner portion D, the marks d, e, and f are overlaid on the alignment region that is the opening of the wiring sheet. By arranging the solar cells in this way, a solar cell with a wiring sheet having an alignment error of 50 μm or less is formed.

  As shown in FIGS. 4 to 6, in both the corner portion A and the corner portion D, two marks a and b and a mark d, respectively, are formed on the extension of the left electrode line shape portion 24 a in the x-axis direction. e is arranged, and one mark c and mark f are arranged on the extension of the right electrode line shape portion 25a. Furthermore, the distance between the mark a and the mark b is different from the distance between the mark d and the mark e. Therefore, for example, when the back electrode type solar battery cell 20 is rotated by 180 ° relative to the wiring sheet 10, all of the marks a, b, c, d, e, and f are replaced with an appropriate wiring sheet. It cannot be overlaid on the alignment area.

  Conventionally, for example, in the alignment region on the wiring sheet side, a narrow portion is provided in the wiring line shape portion, and the narrow portion and the mark on the back surface of the back electrode type solar battery cell are overlapped. In this case, there is a problem that the current collection efficiency is reduced in the narrow portion of the wiring line shape portion. According to the first embodiment, since the alignment region is formed by branching the wiring line shape portion without changing the width of the wiring line shape portion, the current collection efficiency can be favorably maintained. The power generation efficiency can be improved.

  By configuring so that the mark provided on the back electrode type solar cell can be recognized through the alignment region provided on the wiring sheet as described above, the mark on the back surface of the solar cell and the wiring sheet in one observation region Both alignment regions can be observed.

  When the mark passing through the alignment region of the wiring sheet is observed by observing a transmitted image by transmitted light using X-rays, IR light, or the like, the direction of arrow A in FIG. 3 or the direction of arrow B in FIG. Can be recognized from. Further, when the reflection image by reflected light is confirmed using an LED, a halogen lamp or the like, the mark of the back electrode type solar cell and the alignment region of the wiring sheet can be recognized from the direction of the arrow A in FIG. . Positioning by such observation may be performed for each location, and the number of observation devices corresponding to the alignment of the solar cell mark and / or wiring sheet is provided to observe all the marks or alignment regions simultaneously. You may do it.

  In Embodiment 1, when the solar cell mark and the alignment region of the wiring sheet are used, at the time of producing the solar cell, at least a part of the mark of the back electrode type solar cell is a branch of the wiring sheet. The back electrode type solar cell and the wiring sheet are aligned so as to overlap with an alignment region composed of an opening surrounded by the first wiring line shape part including the part and the second wiring line shape part including the branch part. Then, the back electrode type solar cell and the wiring sheet are overlapped. In this way, the back electrode type solar cell and the wiring sheet can be aligned with high accuracy to form a solar cell with a wiring sheet. In this state, it is desirable that the back electrode type solar cell and the wiring sheet are fixed by temporary fixing such as partially bonding them with an adhesive so as to maintain the relative position between the back electrode type solar cell and the wiring sheet.

  The manufacturing method of the photovoltaic cell with a wiring sheet in this Embodiment is as follows, for example. An electrode line shape portion extending in the first direction, and an electrode extension portion provided on an extension line in the first direction of the electrode line shape portion so as to be a part of the electrode and separated from the electrode line shape portion A back electrode solar cell comprising: a region between the electrode line shape portion and the electrode extension portion; and a mark provided in at least a part of the region adjacent to the region where the electrode is not present. prepare. The first wiring and the second wiring each include a first wiring and a second wiring that are electrically insulated, and the first wiring and the second wiring each extend in a first direction, and a plurality of second wiring lines. A first wiring line shape portion and a second wiring line shape portion are alternately arranged, and at least a part of each of the first wiring line shape portion and the second wiring line shape portion is branched. A wiring sheet is prepared in which an opening surrounded by a first wiring line shape portion including the branch portion and a second wiring line shape portion including the branch portion is formed. The back electrode solar cell and the wiring sheet are aligned and overlapped so that at least a part of the mark of the back electrode solar cell overlaps the opening of the wiring sheet.

(Solar cell module)
FIG. 11A and FIG. 11B are schematic cross-sectional views illustrating an example of a method for manufacturing an example of a solar cell (solar cell module) in the present embodiment. Hereinafter, with reference to FIG. 11 (a) and FIG. 11 (b), an example of the manufacturing method of an example of the solar cell module in Embodiment 1 using the solar cell with the wiring sheet manufactured as described above. Will be described.

  First, as shown to Fig.11 (a), while installing the 1st transparent resin 31a and the transparent substrate 33 in the light-receiving surface side of a back electrode type photovoltaic cell, it is 2nd transparent resin in the back surface side of a wiring sheet. 31b and the back surface protection sheet 32 are installed. Here, as a solar cell with a wiring sheet, a solar cell with a wiring sheet prepared by electrically connecting a plurality of solar cells as described above, as well as a plurality of divided solar cells with a wiring sheet You may use the photovoltaic cell with a wiring sheet produced by electrically connecting battery cells.

  Next, the first transparent resin 31a is crimped to each back electrode type solar cell, and the second transparent resin 31b is heat-treated in a state of being crimped to the wiring sheet. The second transparent resin 31b is integrated and cured. As a result, as shown in FIG. 11B, the wiring sheet and the solar cell are sealed in the sealing material 31 formed by integrating the first transparent resin 31a and the second transparent resin 31b. A solar cell module is produced.

  In the solar cell module shown in FIG. 11B, the back electrode type solar cell is strongly pressed against the wiring sheet by the expansion and contraction force of the sealing material 31, and the first conductive type electrode line 24 of the back electrode type solar cell. And the first wiring 12 of the wiring sheet and the crimping of the second conductive type electrode line 25 of the back electrode type solar cell and the second wiring 13 of the wiring sheet are strengthened, respectively. A good electrical connection is obtained between the electrode of the battery cell and the wiring of the wiring sheet.

  In the vicinity of the alignment region, as shown in FIGS. 9 and 10, the branch portion 12a 'of the first wiring line shape portion is connected to the first conductivity type electrode line 24b. The branch portion 12 a ″ of the first wiring line shape portion is connected to the first conductivity type electrode line 24. The branch portion 13a 'of the second wiring line shape portion is connected to the second second conductivity type electrode line 25a. The branch portion 13 a ″ of the second wiring line shape portion is connected to the second conductivity type electrode line 25.

  The pressure bonding and heat treatment for sealing the solar cell with wiring sheet in the sealing material 31 can be performed using, for example, a vacuum pressure bonding and heat treatment apparatus called a laminator. For example, the first transparent resin 31a and the second transparent resin 31b are thermally deformed by a laminator, and the first transparent resin 31a and the second transparent resin 31b are thermally cured, so that these transparent resins are integrated. The sealing material 31 is formed, and the solar cell with wiring sheet is encapsulated in the sealing material 31 to be sealed.

  The vacuum pressure bonding is a process of pressure bonding in an atmosphere reduced in pressure from atmospheric pressure. Here, when vacuum pressure bonding is used as the pressure bonding method, it is difficult to form a gap between the first transparent resin 31a and the second transparent resin 31b, and the first transparent resin 31a and the second transparent resin are not formed. This is preferable in that air bubbles tend not to remain in the sealing material 31 formed integrally with the resin 31b. In addition, when vacuum pressing is used, it tends to be advantageous for securing a uniform pressing force between the back electrode type solar cell and the wiring sheet.

  Here, as the transparent substrate 33, any substrate that is transparent to sunlight can be used without any particular limitation, and for example, a glass substrate or the like can be used.

  As the first transparent resin 31a and the second transparent resin 31b, a resin transparent to sunlight can be used without any particular limitation. The first transparent resin 31a and the second transparent resin 31b may be the same type of transparent resin or different types of transparent resin.

  What is necessary is just to adjust suitably the heat processing at the time of sealing said photovoltaic cell with a wiring sheet in the sealing material 31 with melting | fusing point of the 1st transparent resin 31a and the 2nd transparent resin 31b.

  In order to make the above electrical connection stronger and more reliable, for example, an adhesive such as non-conductive paste (NCP) or anisotropic conductive paste (ACP) or a conductive bonding material such as solder may be used. it can. In this case, it is desirable that NCP or ACP is coated with a pattern or transparent so as not to hinder the observation of the mark of the solar battery cell. Moreover, it is desirable that ACP and solder are applied to at least one of the back electrode of the solar battery cell and the wiring of the wiring sheet.

  As the back surface protection sheet 32, any material can be used without particular limitation as long as it can protect the back surface of the sealing material 31. For example, a conventionally used weathering film such as PET can be used.

  From the viewpoint of sufficiently suppressing permeation of water vapor and oxygen into the sealing material 31 and ensuring long-term reliability, the back surface protection sheet 32 may include a metal film such as aluminum.

  The end face of the solar cell module can be completely adhered to the end face using a moisture permeation prevention tape such as an elastomer or butyl rubber tape.

  In an example of the solar cell module of the present invention produced as described above, a frame made of, for example, an aluminum alloy may be attached so as to surround the outer periphery of the solar cell module.

(Other configurations and functions)
Needless to say, the solar cell in Embodiment 1 is not limited to the above-described configuration, and various configurations can be employed. For example, although the electrical connection between the solar battery cell and the wiring sheet has been described in the case of all in series, the electrical connection may be in series, parallel, or a combination of series and parallel.

  In the first embodiment, the number of marks is six and the number of alignment areas corresponding to the marks is two. However, regarding the arrangement of the marks and alignment areas, the marks do not have rotational symmetry and can overlap the alignment areas. There is no particular limitation.

  In the above description, in the alignment of the solar battery cells and the wiring sheet, when the solar battery cells are arranged on the wiring sheet, the portions including the alignment region of the wiring sheet are observed and aligned and overlapped. However, the present invention is not limited to this. For example, when using a cell holding device that holds solar cells and a sheet holding device that holds a wiring sheet, the solar cells and wiring sheets held by these holding devices are relatively moved and overlapped. If the relative movement and superposition can be performed with sufficient accuracy, the solar cell is aligned with the cell holding device using the above-described mark, and the above-described wiring sheet alignment region is used. Then, after alignment with the sheet holding device, the solar cells and the wiring sheet may be relatively moved and overlapped without observing the portion including the alignment region of the wiring sheet. In this case, it is possible to confirm whether or not these are overlaid at an appropriate position by observing a portion including the alignment region of the wiring sheet after the solar battery cell and the wiring sheet are overlaid.

  As described above, according to the solar cell in the first embodiment, the mark of the back electrode type solar cell, the first wiring line shape portion including the branch portion of the wiring sheet, and the second wiring line shape portion including the branch portion. The alignment of the solar battery cell and the wiring sheet can be aligned with high accuracy by observing the mark of the solar battery cell through the alignment area of the wiring sheet using the alignment area consisting of the opening surrounded by it can.

  In addition, since it is configured so that at least part of the marks provided on the back electrode type solar cells can be recognized through the alignment region of the wiring sheet, these marks and the alignment region can be observed simultaneously by one observation device. can do. As a result, it is possible to satisfactorily align the solar battery cell and the wiring sheet, and to provide a highly reliable solar battery.

  In the solar cell in the first embodiment, the first electrode extension portion separated from the first electrode line shape portion by the alignment mark is electrically connected to the first wiring line shape portion via the branch portion of the first wiring line shape portion. Connected. Furthermore, the second electrode extension portion separated from the second electrode line shape portion by the alignment mark is electrically connected to the second wiring line shape portion via a branch portion of the second wiring line shape portion. Thereby, the 1st, 2nd electrode extension part formation area located in the edge part side rather than a mark can also be made to function as a power generation field, and it becomes possible to improve the power generation efficiency of a solar cell.

<Embodiment 2>
In Embodiment 2, in the solar cell with a wiring sheet having the same configuration as that of Embodiment 1, openings other than the alignment region formed in the wiring sheet will be described.

(Wiring sheet opening)
As shown in FIG. 7, the wiring sheet includes two openings near the corner portion C and near the corner portion B. FIG. 12 is an enlarged view of a portion indicated by VIII in FIG.

  As shown in FIG. 12, the opening in the vicinity of the corner C has basically the same structure as the opening in the alignment region of the first embodiment. That is, in the wiring of the second embodiment, a plurality of wiring line shape portions 12a and 13a extending in the first direction (y-axis direction in FIG. 7) are alternately provided. At least a part of each of the wiring line shape portions 12a and 13a branches to include branch portions 12a 'and 12a' 'or 13a' and 13a ''.

  The branch portion 12a ′ of the first wiring line shape portion extends on the extension of the first wiring line shape portion 12a closest to the first wiring line shape portion 12a including the branch portion, and the branch portion 12a ″ is It extends on the extension of the first wiring line shape portion 12a that is second closest to the first wiring line shape portion 12a including the branch portion. Both the branch portions 12a 'and 12a' 'branch to the same direction side with respect to the first wiring line shape portion 12a including the branch portion. The first wiring line shape portion 12a including the branch portion and the branch portions 12a ′ and 12a ″ are electrically connected by the first connection pattern 12c extending in the direction orthogonal to the first direction (x-axis direction in FIG. 7). Connected. In addition, the 1st connection pattern 12c is defined as what is contained in the 1st wiring line shape part 12a containing a branch part.

  The branch portion 13a ′ of the second wiring line shape portion extends on the extension of the second wiring line shape portion 13a closest to the second wiring line shape portion 13a including the branch portion, and the branch portion 13a ″ is It extends on the extension of the second wiring line shape portion 13a that is second closest to the second wiring line shape portion 13a including the branch portion. Both the branch portions 13a 'and 13a' 'branch to the same direction side with respect to the second wiring line shape portion 13a including the branch portion. The second wiring line shape portion 13a including the branch portion and the branch portions 13a ′ and 13a ″ are electrically connected by the second connection pattern 13c extending in a direction orthogonal to the first direction (x-axis direction in FIG. 7). Connected. In addition, the 2nd connection pattern 13c is defined as what is contained in the 2nd wiring line shape part 13a containing a branch part.

  The first wiring line shape portion 12a including the branch portion and the branch portion 13a '' of the second wiring line shape portion are adjacent to each other, and the second wiring line shape portion 13a including the branch portion and the branch portion of the first wiring line shape portion. It is adjacent to 12a ″. The first wiring line shape portion 12a including the branch portion, the branch portions 12a ′ and 12a ″ and the first connection pattern 12c, the second wiring line shape portion 13a including the branch portion, the branch portions 13a ′ and 13a ″ and the first connection pattern 12c. No wiring pattern exists in the portion surrounded by the two connection patterns 13c, that is, the portion surrounded by the first wiring line shape portion including the branch portion and the second wiring line shape portion including the branch portion, and the insulating base An opening in which the material is exposed is formed.

  In the second embodiment, there are two branch portions included in the first wiring line shape portion and two branch portions included in the second wiring line shape portion, but the number of branch portions is not particularly limited. Moreover, the wiring pattern that connects the wiring line shape portion and the branch portion is not limited to a straight line, but may be an arc shape. However, it is preferable that the opening of the alignment region of the first embodiment and the opening of the second embodiment have different shapes.

(Alignment of back electrode type solar cells and wiring sheet)
FIG. 9 is a schematic plan view of an example of the solar cell in the second embodiment. FIG. 13 is an enlarged view of a region peripheral portion X including the opening of the wiring sheet shown in FIG.

  As shown in FIG. 9, in the wiring sheet of the second embodiment, the first wiring line shape portion 12a and its branch portions 12a ′ and 12a ″ are the first conductive type electrode lines of the back electrode type solar cell. 24, the second wiring line shape portion 13 a and its branch portions 13 a, 13 a ″ are connected to the second conductivity type electrode line 25.

  The translucent insulating base material is exposed at the opening of the wiring sheet. Therefore, when the back electrode type solar cell and the wiring sheet are aligned and temporarily fixed in order to maintain their relative positions, the wiring sheet between the back electrode type solar cell and the wiring sheet When the ultraviolet curable resin is arranged in a range including at least a part of the opening and the ultraviolet ray is irradiated from the wiring sheet side, the ultraviolet ray passes through the opening and reaches the ultraviolet curable resin. Therefore, the ultraviolet curable resin is cured and the back electrode type solar cell and the wiring sheet can be temporarily fixed.

  The opening of the wiring sheet can be formed at a desired position by appropriately adjusting the shape of the branch portion of the wiring line shape portion. Therefore, in Embodiment 2, the opening can be formed at the same position as the opening of the wiring sheet produced by the existing production equipment. Furthermore, in the solar cell in the second embodiment, since the wiring line shape portion and its branching portion extend outside the opening portion of the wiring sheet, this region can also function as a current collecting region, The luminous efficiency of the solar cell is improved.

  As the ultraviolet curable resin used for temporary fixing, for example, urethane acrylate, acrylic resin acrylate, epoxy acrylate, or the like can be used.

<Embodiment 3>
The third embodiment is a solar cell with a wiring sheet having basically the same configuration as the first and second embodiments. The difference from the first and second embodiments is the structure of the opening for temporarily fixing the wiring sheet. Below, the opening part for temporarily fixing a wiring sheet is demonstrated.

(Wiring sheet opening)
As shown in FIG. 7, the wiring sheet includes a first wiring line region 121 including a plurality of wiring line shape portions having a predetermined length, and the predetermined length arranged on both sides of the first wiring line region. And a second wiring line region 122 composed of a plurality of short wiring line shape portions. The lengths of the first wiring line shape portion and the second wiring line shape portion of the second wiring line region are shortened according to the distance from the first wiring line region. The opening is formed near the tip of the first wiring line shape portion in the second wiring line region. The length from the front end of the first wiring line shape portion that is the branch source to the first wiring connection portion that connects the first wiring line shape portions to each other is longer than the length from the front end of the branch portion to the first wiring connection portion. Also short.

  Here, the first wiring line shape part of the branching source is the first line shape part 12a indicated by one straight line along the first direction among the first wiring line shape parts including the branching part. Branch portions 12 a ′ and 12 a ″ are branched from a branch point Z of the first wiring line shape portion of the branch source. Further, the first wiring connecting portion is, for example, the edge portion of the wiring sheet at the edge of the first wiring line shape portion along the direction orthogonal to the first direction, as indicated by reference numeral 12b in FIG. Are arranged on the side where no is arranged, and the plurality of first wiring line shape portions are electrically connected to each other.

  In the third embodiment, the structure of the two openings in the vicinity of the corner portion C and the vicinity of the corner portion B of the wiring sheet in FIG. 7 is different from that in the second embodiment. Specifically, the structure shown in FIG. ing.

  The length from the front end of the first wiring line shape portion 12a that forms the opening to the first wiring connection portion that connects the first wiring line shape portions is the length of the branch portion 12a ′ and the branch portion 12a ″. It is shorter than the length from the tip to the first wiring connection part. Note that the length from the leading end of the first wiring line shape portion 12a at the branching source, the leading end of the branching portion 12a ′, or the leading end of the branching portion 12a ″ to the first wiring connecting portion refers to the first wiring connecting portion from each leading end. Means the distance along the first direction. According to this, in the third embodiment, in the first wiring line shape portion 12a including the branch portion, the distance from the branch portion Z to the first wiring connection portion is the same as that in the second embodiment (the branch portion Z in FIG. 12). To the first wiring connection portion). Therefore, the resistance value of the first wiring line shape portion including the branch portion of the third embodiment is smaller than the resistance value of the first wiring line shape portion including the branch portion of the second embodiment. Therefore, in the solar cell in Embodiment 3, the current collection efficiency of the wiring pattern is improved, and the light emission efficiency of the solar cell is improved.

<Embodiment 4>
The fourth embodiment is a solar cell with a wiring sheet having basically the same configuration as the first and second embodiments. The difference from the first and second embodiments is the structure of the opening for temporarily fixing the wiring sheet. Below, the opening part for temporarily fixing a wiring sheet is demonstrated.

(Wiring sheet opening)
As shown in FIG. 15, the first wiring line shape portion 12 a including the branch portion extends inside the opening, and extends from the first connection pattern 12 c in the first direction (along the first wiring line shape portion. Extending portion 12d having a width smaller than that of the first wiring line shape portion. Further, the second wiring line shape portion 13a including the branching portion extends inside the opening and extends in the first direction from the second connection pattern 13c and has a narrower width than the second wiring line shape portion. The existing part 13d is included. The width of the extending portion is narrower than the width of the wiring line shape portion means that the length in the direction (x-axis direction in FIG. 7) orthogonal to the extending direction (first direction) of the extending portion is the wiring line. It means that it is shorter than the length in the direction (x-axis direction in FIG. 7) orthogonal to the extending direction (first direction) of the shape portion.

  According to this, as shown in FIG. 16, when the wiring sheet is overlapped with the back electrode type solar cell, the extending portions 12d and 13d of the wiring sheet can also function as a current collecting region, and the light emission of the solar cell Efficiency is improved. Moreover, since the widths of the extending portions 12d and 13d are narrower than the wiring line shape portion, the exposure ratio of the insulating base material is larger than the other portions of the wiring sheet. For this reason, when an ultraviolet curable resin is disposed between the back electrode type solar cell and the wiring sheet in a range including at least a part of the opening of the wiring sheet, and ultraviolet rays are irradiated from the wiring sheet side, the ultraviolet rays are opened. Passes through the part and reaches the ultraviolet curable resin. Therefore, the ultraviolet curable resin is cured and the back electrode type solar cell and the wiring sheet can be temporarily fixed.

  The opening ratio of the opening, that is, the exposure ratio of the insulating base material in the opening is preferably 18% or more, and more preferably 40% or more. According to this, the ultraviolet curable resin can be efficiently cured.

  In FIG. 16, the first wiring line shape portion including the branch portion and the second wiring line shape portion including the branch portion each include two extending portions, and if the number of extending portions is one or more, There is no particular limitation. In addition, the length of the extending portion is not particularly limited as long as it is shorter than the length along the first direction of the opening.

<Embodiment 5>
The fifth embodiment is a solar cell with a wiring sheet basically having the same configuration as that of the first and second embodiments. The difference from the first and second embodiments is the structure of the opening for temporarily fixing the wiring sheet. Below, the opening part for temporarily fixing a wiring sheet is demonstrated.

(Wiring sheet opening)
As shown in FIG. 7, the wiring sheet has an opening formed inside a wiring line region 123 including a plurality of first wiring line shape portions 12 a and a plurality of second wiring line shape portions 13 a.

  In the fifth embodiment, the structure of the two openings near the corner portion C and the corner portion B of the wiring sheet of FIG. 7 is different from that of the second embodiment, and specifically, the structure shown in FIG. ing.

  As shown in FIG. 17, at least one of the first wiring line shape portions 12a has no first wiring portion 30 that has no wiring pattern made of a conductive material and exposes an insulating base material. Has been. The first opening has a width narrower than that of the first wiring line shape portion, and a length shorter than that of the first wiring line shape portion. There is no wiring pattern made of a conductive material in at least one second wiring line shape portion adjacent to the first wiring line shape portion in which the opening is formed, and the insulating base material is exposed. Two openings 31 are formed. The second opening has a width narrower than that of the second wiring line shape portion and a length shorter than that of the second wiring line shape portion. At least a part of each of the first opening and the second opening is on the same line along a second direction (x-axis direction in FIG. 7) orthogonal to the first direction (y-axis direction in FIG. 17). Exists.

  According to this, as shown in FIG. 18, when the wiring sheet is overlapped with the back electrode type solar cell, the first wiring line shape portion and the second wiring line shape portion in which the opening is formed are also other than the opening. This region can be made to function as a current collecting region, and the luminous efficiency of the solar cell is improved.

  In the opening including the first opening 30 and the second opening 31 of the wiring sheet, the translucent insulating base material is exposed. Therefore, when the back electrode type solar cell and the wiring sheet are aligned and temporarily fixed in order to maintain their relative positions, the wiring sheet between the back electrode type solar cell and the wiring sheet When the ultraviolet curable resin is arranged in a range including at least a part of the opening and the ultraviolet ray is irradiated from the wiring sheet side, the ultraviolet ray passes through the opening and reaches the ultraviolet curable resin. Therefore, the ultraviolet curable resin is cured and the back electrode type solar cell and the wiring sheet can be temporarily fixed.

  In FIG. 17, there are three first wiring line shape portions 12 a including the first openings 30 and three second wiring line shape portions 13 a including the second openings 31, but the number of each is one or more. If it is, it will not be specifically limited. The shape of the 1st opening part 30 and the 2nd opening part 31 is not limited to a rectangle, An ellipse may be sufficient. The size of the first opening 30 and the second opening is not particularly limited, and is formed so that the amount of ultraviolet light passing through the entire opening is sufficient to cure the ultraviolet curable resin. It only has to be.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include meanings equivalent to the scope of claims and all modifications within the scope.

  DESCRIPTION OF SYMBOLS 10 Wiring sheet, 11 Insulating base material, 12, 13, 16 Wiring, 12a, 13a Wiring line shape part, 12a ', 13a' Branch part, 12b, 13b Wiring connection part, 12c, 13c Connection pattern, 12d, 13d Extension Current part, 20 Back electrode type solar cell, 21 Semiconductor substrate, 24, 25 Electrode (electrode line), 24a, 25a Electrode line shape part, 24b, 25b Electrode extension part, 30, 31 Opening part, a, b, c , D, e, f mark

Claims (5)

A wiring sheet provided with wiring for electrically connecting back electrode type solar cells,
The wiring includes a first wiring and a second wiring that are electrically insulated,
The first wiring and the second wiring each include a plurality of first wiring line shape portions and a plurality of second wiring line shape portions extending in the first direction,
An opening is formed inside a wiring line region composed of the plurality of first wiring line shape portions and the plurality of second wiring line shape portions.
Wiring sheet. The first wiring line shape portions and the second wiring line shape portions are alternately arranged,
The opening includes a first opening formed in at least one of the first wiring line shape portions, and a second opening formed in at least one of the second wiring line shape portions. Including,
At least a part of each of the first opening and the second opening is on the same line along a second direction orthogonal to the first direction.
The wiring sheet according to claim 1. The first wiring line shape portions and the second wiring line shape portions are alternately arranged,
Each of the first wiring line shape part and the second wiring line shape part includes at least a branch part,
The opening is formed in a region surrounded by a first wiring line shape portion including the branch portion and a second wiring line shape portion including the branch portion.
The wiring sheet according to claim 1. The wiring line area includes a first wiring line area composed of a plurality of wiring line shape portions having a predetermined length, and a plurality of wiring line shapes shorter than the predetermined length disposed on both sides of the first wiring line area. A second wiring line region comprising a portion,
The first wiring line shape portion and the second wiring line shape portion of the second wiring line region are shortened along with the distance from the first wiring line region,
The opening is formed near the tip of the first wiring line shape portion in the second wiring line region,
The length from the front end of the first wiring line shape portion that is the branch source to the first wiring connection portion that connects the first wiring line shape portions to each other is longer than the length from the front end of the branch portion to the first wiring connection portion. Too short,
The wiring sheet according to claim 3. At least one of the first wiring line shape portion including the branch portion and the second wiring line shape portion including the branch portion extends into the opening, and the first wiring line shape portion and the second wiring Including an extended portion that is narrower than the line-shaped portion,
The wiring sheet according to claim 3 or 4.

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