JP2016225446A - Sealing sheet for solar cell module and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pair of sealing sheets which can efficiently produce a solar cell module excellent in power generation efficiency.SOLUTION: A pair of sealing sheets for a solar cell module is provided. The pair of sealing sheets includes a first sealing sheet and a second sealing sheet. The first sealing sheet includes a first conductive portion partially disposed on one surface of the first sealing resin layer. The second sealing sheet includes a second conductive portion that is partially disposed on one surface of the second sealing resin layer. The first conductive portion includes a first conductive path unit having a conductive line, and a ratio (H/W) of a height (H) and a width (W) of the conductive line is 1/2 or less. The area of the second conductive portion in a solar cell opposing region on the surface of the second sealing sheet is larger than the area of the first conductive portion in a solar cell opposing region on the surface of the first sealing sheet.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a solar cell module sealing sheet and a solar cell module.

  Solar cell modules that convert light energy into electric power are widely used as clean power generators. The solar cell module includes a solar cell and a wiring connected to the cell, and the power generated in the cell through the wiring is configured to be supplied to the outside. Patent documents 1-7 are mentioned as literature which discloses this kind of conventional technology. Patent Documents 1 to 5 relate to a solar cell module of a type in which an n-type electrode is partially disposed on the front surface side of the solar battery cell and a p-type electrode is disposed on the back surface side. The present invention relates to a solar cell module that employs a back contact method in which both electrodes are arranged on the back side.

Japanese Patent Laid-Open No. 2005-72115 JP2013-232496A JP 2005-536894 A Japanese Patent No. 5185913 JP 2014-63978 A JP 2010-41009 A JP 2011-238849 A

  In solar cell modules of the type having electrodes on the front and back surfaces, for example, the structures disclosed in Patent Documents 1 and 2 require that the wiring of solar cells must be individually joined using solder etc. And takes time. In addition, when heating is performed at the time of bonding, such as solder bonding, the characteristics of the cell may be reduced by heating, or the cell may be warped or cracked. Solder joints also have a problem of flux contamination. The solar cell modules disclosed in Patent Documents 3 and 4 also have the same problems as Patent Documents 1 and 2 because the wires serving as the conductive paths are soldered. Moreover, the wire is arrange | positioned by the method of embedding in the adhesive bond layer on the resin film different from a sealing member. This method has a large number of parts and processes, and is disadvantageous in terms of production efficiency.

  This invention was created in view of said situation, and it aims at providing a pair of sealing sheet which can manufacture efficiently the solar cell module excellent in electric power generation efficiency. Another object of the present invention is to provide a solar cell module using the sealing sheet.

  According to the present invention, there is provided a pair of sealing sheets that are sealed by sandwiching at least one solar battery cell in the solar battery module. The pair of sealing sheets includes a first sealing sheet disposed on the surface side of the at least one solar battery cell, a second sealing sheet disposed on the back surface side of the at least one solar battery cell, Is provided. The first sealing sheet includes a first sealing resin layer and a first conductive portion partially disposed on one surface of the first sealing resin layer. The second sealing sheet includes a second sealing resin layer and a second conductive portion partially disposed on one surface of the second sealing resin layer. The first conductive part has at least one first conductive path unit. The first conductive path unit has at least one conductive line as a solar cell contact portion. The conductive line of the first conductive path unit has a ratio (H / W) of a height (H) to a width (W) of 1/2 or less. And the area of the said 2nd electroconductive part in the photovoltaic cell opposing area | region of the said 2nd sealing sheet surface is larger than the area of the said 1st electroconductive part in the photovoltaic cell opposing area | region of the said 1st sealing sheet surface.

  Wiring in the solar cell module can be realized by sandwiching the solar cell between the pair of sealing sheets configured as described above. Therefore, the wiring workability of the solar cell module can be improved by using the pair of sealing sheets. Moreover, the 2nd electroconductive part in the photovoltaic cell opposing area | region of the 2nd sealing sheet arrange | positioned at a back surface side is rather than the 1st electroconductive part in the photovoltaic cell opposing area | region of the 1st sealing sheet arrange | positioned at the surface side. By making the area large, it is possible to reduce the series resistance on the back side while preventing an increase in shadow loss, and to improve the current collection efficiency. Furthermore, since the ratio (H / W) between the height and the width of the conductive wire constituting the first conductive portion is set to ½ or less, the stability on the first sealing resin layer (at the time of sealing) It is excellent in the stability of the shape of the conductive wire and the stability of its position, and the contact area with the solar battery cell can be increased. This contributes to improvement in wiring workability and power generation efficiency. By applying the technology disclosed herein, it becomes possible to easily change the shape (typically the area) of the conductive portion on the front surface side and the back surface side, and in such a configuration, the type having electrodes on the front and back surfaces Improvement of power generation efficiency in the solar cell module is efficiently realized.

  In a preferred aspect of the technology disclosed herein (including a pair of sealing sheets, a solar cell module, and a manufacturing method thereof, the same shall apply hereinafter), the second conductive portion includes at least one second conductive path unit. Have The second conductive path unit preferably has a plurality of conductive lines as a solar cell contact portion. The number of the conductive lines in the second conductive path unit is preferably larger than the number of the conductive lines in the first conductive path unit. Further / or preferably, the width of the conductive line in the second conductive path unit is larger than the width of the conductive line in the first conductive path unit. By using the sealing sheet having such a configuration, a solar cell module excellent in power generation efficiency is preferably realized.

  In another preferred aspect, the second conductive portion has at least one second conductive path unit. It is preferable that the second conductive path unit is disposed in substantially the entire region of the solar cell facing region on the surface of the second sealing sheet. By using the sealing sheet having such a configuration, a solar cell module particularly excellent in power generation efficiency is preferably realized.

  In a preferred aspect of the technology disclosed herein, the conductive line of the first conductive path unit has a rectangular shape in a cross section orthogonal to the longitudinal direction of the conductive line. By comprising in this way, the stability on the 1st sealing resin layer of a conductive wire improves further, and the upper surface of a conductive wire contacts a solar cell surface favorably.

  In a preferred aspect of the technology disclosed herein, the height of the conductive line of the first conductive path unit is 50 to 300 μm, and the width of the conductive line is 100 to 1200 μm. By adopting a conductive wire having the above height and width and satisfying the above ratio (H / W), a solar cell module excellent in power generation efficiency is preferably realized.

  In a preferred aspect of the technology disclosed herein, in the first conductive path unit, the at least one conductive line is a plurality of conductive lines arranged at intervals. By using the sealing sheet having such a configuration, a solar cell module excellent in power generation efficiency is preferably realized.

  By using the pair of sealing sheets having the above configuration, a solar cell module having excellent power generation efficiency can be efficiently manufactured. Therefore, according to this invention, a solar cell module provided with an at least 1 photovoltaic cell and any one pair of sealing sheet disclosed here is provided.

It is a top view which shows typically the principal part of the 1st sealing sheet which concerns on 1st Embodiment. It is sectional drawing in the II-II line of the 1st sealing sheet of FIG. It is a top view which shows typically the principal part of the 2nd sealing sheet which concerns on 1st Embodiment. It is an exploded sectional view showing typically the structure of the principal part of the solar cell module concerning a 1st embodiment. It is a top view which shows typically the principal part of the 2nd sealing sheet which concerns on 2nd Embodiment. It is a top view which shows typically the principal part of the 2nd sealing sheet which concerns on 3rd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field. Further, in the following drawings, members / parts having the same action are described with the same reference numerals, and overlapping descriptions may be omitted or simplified. In addition, the embodiments described in the drawings are schematically illustrated in order to clearly explain the present invention, and do not necessarily accurately represent the size and scale of a product actually provided.

<< First Embodiment >>
FIG. 1 is a top view schematically showing the main part of the first sealing sheet according to the first embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II of the first sealing sheet of FIG.

(A pair of sealing sheets)
The 1st sealing sheet 110 is utilized as one of a pair of sealing sheet 100 sealed on both sides of a photovoltaic cell in a solar cell module. The 1st sealing sheet 110 is a sealing sheet with an electroconductive part arrange | positioned at the surface side of a photovoltaic cell, and as shown to FIG. 1,2, the 1st sealing resin layer 120 and the 1st electroconductive part 130 are shown. And comprising. In addition, since the 1st sealing sheet 110 and the 2nd sealing sheet 210 mentioned later have an electroconductive part, they are also called a sealing sheet with an electroconductive part from a structural surface, or a current collection sealing sheet from a functional surface. .

  The 1st sealing resin layer 120 seals a photovoltaic cell in a solar cell module so that it may mention later. On the first surface 120A of the first sealing resin layer 120, the first conductive portion 130 is disposed. The first conductive part is not provided on the second surface (first conductive part non-formation surface) of the first sealing resin layer 120, and this surface constitutes the outer surface of the first sealing sheet 110. Yes.

  The first conductive portion 130 is partially disposed on the first surface 110 </ b> A of the first sealing sheet 110 and constitutes a part of the first surface 110 </ b> A of the first sealing sheet 110. A portion where the first conductive portion 130 is not formed on the first surface 120A of the first sealing resin layer 120 (a portion where the first conductive portion is not formed) is exposed as the outer surface of the first sealing sheet 110. And constitutes a part of the first surface 110 </ b> A of the first sealing sheet 110. Alternatively, when an additional layer such as an adhesive layer is disposed on the surface of the first sealing resin layer 120, the surface of the additional layer is a part of the first surface 110 </ b> A of the first sealing sheet 110. The part can be configured.

  The first conductive unit 130 includes a plurality of first conductive path units 140a and 140b. The first conductive path units 140a and 140b are arranged so as to correspond to the solar cells when the solar cell module is constructed. In this embodiment, the first conductive path units 140a and 140b exist separately from each other and each has a continuous structure.

  Moreover, 110 A of 1st surfaces of the 1st sealing sheet 110 are the area | region (solar cell opposing area | region) 105a, 105b which opposes the surface of one photovoltaic cell when encapsulating a photovoltaic cell, and one sun. A region (a solar cell non-opposing region) 107 that does not face the surface of the battery cell. The first conductive path unit 140a includes, on the first surface 110A of the first sealing sheet 110, a solar cell contact portion 150a located in the solar cell facing region 105a and a connection portion located in the solar cell non-facing region 107. 160a. Note that the solar cell contact portion 150a is a portion that contacts (typically abuts) the solar cell when sealing the solar cell, and in the first sealing sheet 110, Means the part where the contact is planned.

  In the first conductive path unit 140a, the solar cell contact portion 150a has a shape extending toward the connection portion 160a, and the solar cell contact portion 150a is connected to the connection portion 160a at one end (specifically, Is fixed). More specifically, the solar cell contact portion 150a is configured by a plurality of conductive lines 155a extending linearly on the first surface 110A of the first sealing sheet 110. The plurality of conductive lines 155a are arranged at intervals. In this embodiment, the conductive lines 155a extend in a straight line and are arranged in parallel at a predetermined interval. For simplicity, only three conductive lines 155a are shown in FIG.

  The conductive line 155a has a ratio (H / W) between the height (H) and the width (W) shown in FIG. Accordingly, the first conductive path unit 140a including the conductive line 155a exhibits excellent shape stability, and is not easily affected by the deformation or the like of the first sealing resin layer 120 on the first sealing resin layer 120. Become. The ratio (H / W) is preferably about 1/3 or less from the viewpoint of shape stability, and is preferably 1/5 or more (for example, 1/4 or more) from the viewpoint of power generation efficiency. Note that the height (H) and width (W) of the conductive wire are typically the height (H) and width (W) in a cross section perpendicular to the longitudinal direction of the conductive wire.

  The conductive wire 155a has a rectangular shape in a cross section orthogonal to the longitudinal direction. Thereby, the whole upper surface of the conductive wire 155a can be in surface contact with the surface of the solar battery cell. The conductive wire 155a having the above shape is also excellent in shape stability. In this embodiment, the conductive wire 155 a is arranged such that the long side (upper side) of the rectangular cross section is the surface of the first surface 110 </ b> A of the first sealing sheet 110. Note that the cross-sectional shape of the conductive wire 155a is not limited thereto, and may be a circular shape, an elliptical shape, a semicircular shape, a trapezoidal shape, a triangular shape, or the like. From the viewpoint of the contact area with the solar battery cell, the conductive wire 155a (and thus the solar battery cell contact portion 150a) preferably has a flat portion (typically the upper surface) in contact with the solar battery cell.

  The connection portion 160a of the first conductive path unit 140a has a band shape extending in a direction intersecting (specifically, substantially orthogonal) with the longitudinal direction of the conductive lines 155a (which may also be the arrangement direction of solar cells). One end of the conductive wire 155a is connected (specifically fixed) to the connection portion 160a. That is, one end of each of the plurality of conductive lines 155a is connected to the connection portion 160a to be a fixed end. On the other hand, no connection portion is arranged on the other end side of each of the plurality of conductive lines 155a, and the other end of the conductive line 155a is a free end in the first conductive path unit 140a. The first conductive path unit 140a has a comb shape when viewed from above. In other words, the first conductive path unit 140a has a comb shape in which a plurality of conductive lines 155a extend in a tooth shape from the connection portion 160a serving as a base. In addition, the connection part 160a is typically arrange | positioned in a non-contact state with a photovoltaic cell, when sealing a photovoltaic cell with the 1st sealing sheet 110. FIG.

  The first conductive path unit 140b is disposed adjacent to the first conductive path unit 140a at a distance from the first conductive path unit 140a. Specifically, the first conductive path units 140a and 140b are arranged at intervals (in the arrangement direction of the solar cells) so as to correspond to the solar cell facing regions 105a and 105b, respectively. As for other matters, the first conductive path unit 140b has the same shape, structure, arrangement relationship and the like as the first conductive path unit 140a. Briefly, the first conductive path unit 140b has a solar cell contact portion 150b and a connection portion 160b, similar to the first conductive path unit 140a, and the solar cell contact portion 150b and the connection portion 160b are The solar cell contact portion 150a and the connection portion 160a have the same shape, structure, arrangement relationship, and the like. Therefore, the conductive wire 155b included in the solar cell contact portion 150b also has the same shape, structure, positional relationship, and the like as the conductive portion 155a.

  By arranging the first conductive part 130 including the first conductive path units 140a and 140b as described above, the first surface 110A of the first sealing sheet 110 includes the first conductive path units 140a and 140b. A part pattern is formed. In this embodiment, as shown in part of FIG. 1, a pattern in which a plurality of first conductive path units 140a, 140b having a comb shape are arranged in a plurality of rows at a predetermined interval is a first seal. It is formed on the first surface 110 </ b> A of the stop sheet 110.

  FIG. 3 is a top view schematically showing the main part of the second sealing sheet according to the first embodiment.

  The 2nd sealing sheet 210 is utilized as the other of a pair of sealing sheet 100 sealed on both sides of a photovoltaic cell in a solar cell module. The 2nd sealing sheet 210 is a sealing sheet with an electroconductive part arrange | positioned at the back surface side of a photovoltaic cell, and as shown in FIG. 3, the 2nd encapsulating resin layer 220, the 2nd electroconductive part 230, Is provided.

  The 2nd sealing resin layer 220 seals a photovoltaic cell in a solar cell module as mentioned later. On the first surface 220A of the second sealing resin layer 220, the second conductive portion 230 is disposed. The second conductive portion is not provided on the second surface (second conductive portion non-formation surface) of the second sealing resin layer 220, and this surface constitutes the outer surface of the second sealing sheet 210. Yes.

  The second conductive portion 230 is partially disposed on the first surface 210 </ b> A of the second sealing sheet 210 and constitutes a part of the first surface 210 </ b> A of the second sealing sheet 210. Note that a portion where the second conductive portion 230 is not formed on the first surface 220A of the second sealing resin layer 220 (a portion where the second conductive portion is not formed) is exposed as the outer surface of the second sealing sheet 210. And constitutes a part of the first surface 210 </ b> A of the second sealing sheet 210. Alternatively, when an additional layer such as an adhesive layer is disposed on the surface of the second sealing resin layer 220, the surface of the additional layer is a part of the first surface 210 </ b> A of the second sealing sheet 210. The part can be configured.

  The second conductive unit 230 includes a plurality of second conductive path units 240a and 240b. The second conductive path units 240a and 240b are arranged so as to correspond to the solar cells when the solar cell module is constructed. In this embodiment, the second conductive path units 240a and 240b exist separately from each other and each has a continuous structure.

  In addition, the first surface 210A of the second sealing sheet 210 includes regions (solar cell facing regions) 205a and 205b that face the surface of one solar cell when the solar cell is sealed, and one solar cell. A region (a solar cell non-opposing region) 207 that does not face the surface of the battery cell. The second conductive path unit 240a includes, on the first surface 210A of the second sealing sheet 210, a solar cell contact portion 250a located in the solar cell facing region 205a and a connecting portion located in the solar cell non-facing region 207. 260a. Note that the solar cell contact portion 250a is a portion that contacts (typically abuts) the solar cell when sealing the solar cell, and in the second sealing sheet 210, the solar cell and Means the part where the contact is planned.

  In the second conductive path unit 240a, the solar cell contact portion 250a has a shape extending toward the connection portion 260a, and the solar cell contact portion 250a is connected to the connection portion 260a at one end thereof (specifically, Is fixed). Further, the solar cell contact portion 250a is composed of a plurality of conductive wires 255a extending linearly on the first surface 210A of the second sealing sheet 210. The plurality of conductive lines 255a are arranged at intervals. In this embodiment, the conductive lines 255a extend in a straight line and are arranged in parallel at a predetermined interval.

  The number of the conductive lines 255a is larger than the number of the conductive lines 155a constituting the first conductive path unit 140a in the first sealing sheet 110. Specifically, in the first conductive path unit 140a and the second conductive path unit 240a corresponding to one solar battery cell, the number of conductive lines 255a in the second conductive path unit 240a that can contact the back surface of the solar battery cell is The number is larger than the number of conductive lines 155a in the first conductive path unit 140a that can contact the surface of the solar battery cell. Thereby, the power generation efficiency of the solar cell module is improved. In this embodiment, the number of conductive lines 155a in the first conductive path unit 140a is three, and the number of conductive lines 255a in the second conductive path unit 240a is six. However, the present invention is not limited to this. For example, the number of conductive lines 255a in the second conductive path unit 240a is one or more (more preferably two or more, more preferably five or more) than the number of conductive lines 155a in the first conductive path unit 140a. Preferably, the number of conductive lines 255a may be twice or more the number of conductive lines 155a.

  The conductive line 255a preferably has a ratio (H / W) of a height (H) to a width (W) set to ½ or less. Accordingly, the second conductive path unit 240a including the conductive line 255a exhibits excellent shape stability, and is not easily affected by the deformation of the second sealing resin layer 220 on the second sealing resin layer 220. Become. The ratio (H / W) is more preferably about 1/3 or less from the viewpoint of shape stability, and preferably 1/5 or more (for example, 1/4 or more) from the viewpoint of power generation efficiency. Note that the height (H) and width (W) of the conductive wire are typically the height (H) and width (W) in a cross section perpendicular to the longitudinal direction of the conductive wire.

  The conductive wire 255a preferably has a rectangular shape in a cross section perpendicular to the longitudinal direction thereof. Thereby, the whole upper surface of the conductive wire 255a can be in surface contact with the surface of the solar battery cell. The conductive wire 255a having the above shape is also excellent in shape stability. In this embodiment, the conductive wire 255 a is disposed such that the long side (upper side) of the rectangular cross section is the surface of the first surface 210 </ b> A of the second sealing sheet 210. Note that the cross-sectional shape of the conductive wire 255a is not limited thereto, and may be a circular shape, an elliptical shape, a semicircular shape, a square shape, a trapezoidal shape, a triangular shape, or the like. From the viewpoint of the contact area with the solar battery cell, the conductive wire 255a (and thus the solar battery cell contact portion 250a) preferably has a flat portion (typically the upper surface) in contact with the solar battery cell.

  The connection portion 260a of the second conductive path unit 240a has a strip shape extending in a direction intersecting (specifically substantially orthogonal) with the longitudinal direction of the conductive lines 255a (which may also be the arrangement direction of solar cells). One end of the conductive wire 255a is connected (specifically fixed) to the connection portion 260a. That is, one end of each of the plurality of conductive lines 255a is connected to the connection portion 260a to be a fixed end. On the other hand, no connection portion is disposed on the other end side of each of the plurality of conductive lines 255a, and in the second conductive path unit 240a, the other end of the conductive line 255a is a free end. The second conductive path unit 240a has a comb shape when viewed from above. In other words, the second conductive path unit 240a has a comb shape in which a plurality of conductive lines 255a extend in a tooth shape from the connection portion 260a serving as a base. In addition, the connection part 260a is typically arrange | positioned in a non-contact state with a photovoltaic cell, when a photovoltaic cell is sealed with the 2nd sealing sheet 210. FIG.

  The second conductive path unit 240b is disposed next to the second conductive path unit 240a at a distance from the second conductive path unit 240a. Specifically, the second conductive path units 240a and 240b are arranged at intervals (in the arrangement direction of the solar cells) so as to correspond to the solar cell facing regions 205a and 205b, respectively. Regarding other matters, the second conductive path unit 240b has the same shape, structure, arrangement relationship, and the like as the second conductive path unit 240a. Briefly, the second conductive path unit 240b has a solar cell contact portion 250b and a connection portion 260b, similar to the second conductive path unit 240a, and the solar cell contact portion 250b and the connection portion 260b are The solar cell contact portion 250a and the connection portion 260a have the same shape, structure, arrangement relationship, and the like. Therefore, the conductive wire 255b included in the solar cell contact portion 250b also has the same shape, structure, positional relationship, and the like as the conductive portion 255a.

  By arranging the second conductive part 230 including the second conductive path units 240a and 240b as described above, the first surface 210A of the second encapsulating sheet 210 includes the second conductive path units 240a and 240b. A part pattern is formed. In this embodiment, as shown in FIG. 3, a pattern in which a plurality of second conductive path units 240 a and 240 b having a comb shape are arranged in a plurality of rows at a predetermined interval is formed as a second seal. It is formed on the first surface 210 </ b> A of the stop sheet 210.

(Solar cell module)
FIG. 4 is an exploded cross-sectional view schematically showing the structure of the main part of the solar cell module according to the first embodiment. Hereinafter, a solar cell module constructed using a pair of sealing sheets will be described with reference to FIG.

  As shown in FIG. 4, the solar cell module 300 includes a plurality of solar cells including solar cells 305a and 305b. Moreover, the solar cell module 300 is provided with the 1st sealing sheet 110 which covers the surface of the photovoltaic cell 305a, 305b, and the 2nd sealing sheet 210 which covers the back surface of the photovoltaic cell 305a, 305b. Furthermore, the solar cell module 300 includes a surface covering member 320 disposed on the outer side (upper side) of the first sealing sheet 110 and a rear surface covering member disposed on the outer side (lower side) of the second sealing sheet 210. 330. The surface covering member 320 and the back surface covering member 330 constitute the front (front) surface and the back (back) surface of the solar cell module 300, respectively.

  The solar battery cell group 302 including a plurality of solar battery cells including the solar battery cells 305a and 305b is arranged in a straight line at a predetermined interval. An n-type electrode (surface electrode) is partially formed on the surface of the solar battery cells 305a and 305b, and a p-type electrode (back electrode) is formed on the back surface. Although not particularly illustrated, the solar cell modules 300 are arranged in a row so as to be parallel to the arrangement direction of the solar cell groups 302 in addition to the solar cell groups 302 arranged in a row as described above. The solar battery cell group is provided.

  As the first sealing sheet 110, the above-described one is used, and the first conductive path units 140 a and 140 b constituting the first conductive portion 130 have a predetermined interval in the arrangement direction of the solar battery cell group 302. Are arranged separately. The first conductive path units 140a and 140b are arranged so as to face and come into contact with the surfaces (more specifically, surface electrodes) of two adjacent solar cells 305a and 305b, respectively. The first conductive path unit 140a is not in contact with solar cells other than the solar cells 305a, and the first conductive path unit 140b is not in contact with solar cells other than the solar cells 305b. . By providing the first conductive portion 130 on the first sealing sheet 110, the bus bar (typically, solder-coated copper wire) provided on the surface of the conventional solar battery cell is not necessary.

  The first conductive path unit 140a includes a solar cell contact portion 150a that faces the solar cell 305a. The first conductive path unit 140a extends from the solar cell contact portion 150a along the arrangement direction of the solar cells 305a and 305b and protrudes into a region located between the solar cells 305a and 305b. The connection portion 160a is provided in the part. In other words, the first conductive path unit 140a has a solar cell contact portion 150a and a portion that protrudes into a region located between the solar cells 305a and 305b, and the protruding portion has a connection portion 160a. . As described above, the protruding portion is provided in the first conductive path unit 140 a, and the connecting portion 160 a is disposed in the protruding portion, so that the first conductive path unit 140 a of the first conductive portion 130 is the second conductive portion 230. The second conductive path unit 240b is easily electrically connected.

  The first conductive path unit 140a has a plurality of conductive lines 155a as described above and shown in FIG. These conductive lines 155a extend linearly in a direction parallel to the arrangement direction of the solar battery cell group 302, and are arranged at a predetermined interval in a direction orthogonal to the arrangement direction. More specifically, each of the conductive lines 155a has a linearly extending shape, and is disposed so as to be spaced from and parallel to each other. The conductive wire 155a is arranged in a region 105a facing the solar battery cell 305a on the first surface 110A of the first sealing sheet 110, and linearly extends to a region located between the solar battery cells 305a and 305b. It extends and is connected to the connection portion 160a.

  The connection portion 160a of the first conductive path unit 140a is disposed in the solar cell non-facing region 107 between the plurality of solar cells 305a and 305b on the surface 110A of the first sealing sheet 110. Moreover, the connection part 160a is arrange | positioned so that it may extend in strip | belt shape in the direction which cross | intersects the arrangement direction of the photovoltaic cell group 302 (specifically substantially orthogonal). As a result, the first conductive path unit 140a contacts the solar battery cell 305a, and the connecting portion 160a contacts another wiring member. Specifically, the connection portion 160a contacts the connection portion 260b of the second conductive path unit 240b that contacts the solar battery cell 305b between the solar battery cells 305a and 305b. Further, although not particularly illustrated, in the first conductive portion 130 of the first sealing sheet 110, the first conductive path unit positioned at the end in the arrangement direction among the plurality of first conductive path units arranged at intervals. The connecting portion can be in contact with the extraction electrode (not shown) in the solar cell non-facing region outside the solar cell facing region.

  The first conductive path unit 140b is basically configured in the same manner as the first conductive path unit 140a, and the solar cell contact portion 150b, the conductive line 155b, and the connection portion 160b are also the solar cell contact portion 150a and the conductive line, respectively. Since the configuration is basically the same as 155a and the connection portion 160a, overlapping description is omitted.

  The above-mentioned thing is used as the 2nd sealing sheet 210, The 2nd conductive path unit 240a, 240b which comprises the 2nd conductive part 230 has a predetermined space | interval in the arrangement direction of the photovoltaic cell group 302. FIG. Are arranged separately. The second conductive path units 240a and 240b are arranged so as to face and come in contact with the back surfaces (more specifically, back electrode) of the two adjacent solar cells 305a and 305b. The second conductive path unit 240a is not in contact with solar cells other than the solar cells 305a, and the second conductive path unit 240b is not in contact with solar cells other than the solar cells 305b. . By providing the 2nd electroconductive part 230 in the 2nd sealing sheet 210, the bus bar (typically solder covering copper wire) provided in the conventional photovoltaic cell back surface becomes unnecessary.

  The second conductive path unit 240b has a solar cell contact portion 250b that is in opposed contact with the solar cell 305b. The second conductive path unit 240b extends from the solar cell contact portion 250b along the arrangement direction of the solar cells 305a and 305b and protrudes into a region located between the solar cells 305a and 305b. The connection part 260b is provided in the part. In other words, the second conductive path unit 240b has a solar cell contact portion 250b and a portion that protrudes into a region located between the solar cells 305a and 305b, and the protruding portion has a connection portion 260b. . As described above, the protruding portion is provided in the second conductive path unit 240 b, and the connection portion 260 b is disposed in the protruding portion, so that the second conductive path unit 240 b of the second conductive portion 230 is connected to the first conductive portion 130. The first conductive path unit 140a is easily electrically connected.

  The second conductive path unit 240b has a plurality of conductive lines 255b as described above and shown in FIG. These conductive lines 255b extend linearly in a direction parallel to the arrangement direction of the solar battery cell group 302, and are arranged at a predetermined interval in a direction orthogonal to the arrangement direction. More specifically, the conductive lines 255b each have a linearly extending shape, and are arranged so as to be spaced apart from and parallel to each other. The conductive wire 255b is arranged in a region 205b facing the solar battery cell 305b on the first surface 210A of the second sealing sheet 210, and linearly extends to a region located between the solar battery cells 305a and 305b. It extends and is connected to the connection portion 260b.

  The connection portion 260b of the second conductive path unit 240b is disposed in the solar cell non-facing region 207 between the plurality of solar cells 305a and 305b on the surface 210A of the second sealing sheet 210. Moreover, the connection part 260b is arrange | positioned so that it may extend in strip | belt shape in the direction which cross | intersects the arrangement direction of the photovoltaic cell group 302 (specifically substantially orthogonal). As a result, the second conductive path unit 240b comes into contact with the solar battery cell 305b, and its connecting portion 260b comes into contact with another wiring member. Specifically, the connection portion 260b contacts the connection portion 160a of the first conductive path unit 140a that is in contact with the solar battery cell 305a between the solar battery cells 305a and 305b. Further, although not particularly illustrated, in the second conductive portion 230 of the second sealing sheet 210, the second conductive path units positioned at the end in the arrangement direction among the plurality of second conductive path units arranged at intervals. The connecting portion can be in contact with the extraction electrode (not shown) in the solar cell non-facing region outside the solar cell facing region.

  The second conductive path unit 240a is basically configured in the same manner as the second conductive path unit 240b, and the solar cell contact portion 250a, the conductive line 255a, and the connection portion 260a are also the solar cell contact portion 250b and the conductive line, respectively. Since the configuration is basically the same as 255b and the connection portion 260b, a duplicate description is omitted.

  The solar cells other than the solar cells 305a and 305b, the first conductive path units other than the first conductive path units 140a and 140b in the first conductive portion 130, the second conductive path units 240a in the second conductive portion 230, Regarding the shape, structure, arrangement relationship, etc. of the second conductive path units other than 240b, from the viewpoint of efficiently performing the wiring work, the solar cells 305a, 305b, the first conductive path units 140a, 140b, the second conductive path units It is preferably configured basically in the same manner as the structural unit composed of 240a and 240b, and more preferably configured so that the same structural unit is repeated.

  With the configuration as described above, in the solar cell module 300, the first conductive portion 130 and the second conductive portion 230 have one surface of two adjacent solar cells (for example, the surface of the solar cell 305a) and the other. The conductive path between the back surfaces (for example, the back surface of the solar battery cell 305b) is formed. When the solar cells are further arranged, the first conductive portion 130 and the second conductive portion 230 can electrically connect the front and back surfaces of the solar cells alternately. As a result, the wiring of the solar battery cell group 302 is realized. The electric power generated in the solar cell group 302 passes through terminal bars (not shown) as extraction electrodes arranged at both ends of the solar cell module 300 in the arrangement direction of the solar cell group 302, and then the solar cell module. 300 is supplied to the outside. Since the technique disclosed here can be implemented basically using a conventionally known existing configuration except that the sealing sheet with a conductive portion is used as the sealing sheet, it is necessary to replace the entire equipment. There is no practical advantage.

  In the above-described configuration, a pair of the above-mentioned encapsulating sheet with a conductive part is prepared, and at least one solar cell is sandwiched between the pair of encapsulating sheets with an electroconductive part, and the conductive part and the at least one solar cell are This is realized by abutting. Specifically, when constructing the solar cell module 300, the pair of encapsulating sheets 100 including the first encapsulating sheet 110 and the second encapsulating sheet 210 so that the conductive part forming surfaces face each other, The solar cells 305a and 305b are sandwiched. And if a pair of sealing sheet 100 is pressed on photovoltaic cell 305a, 305b, the 1st conductive part 130 of the 1st sealing sheet 110 and the 2nd conductive part 230 of the 2nd sealing sheet 210 will each be equipped. The contact portions 160a and 160b and the connection portions 260a and 260b are brought into contact with each other, whereby the solar cell module 300 is electrically connected. More specifically, the solar cell contact portion 150a of the first conductive path unit 140a and the solar cell contact portion 250a of the second conductive path unit 240a abut on the solar cell 305a. Further, the solar cell contact portion 150b of the first conductive path unit 140b and the solar cell contact portion 250b of the second conductive path unit 240b are in contact with the solar cell 305b. Then, the connection portion 160a of the first conductive path unit 140a and the connection portion 260b of the second conductive path unit 240b abut. In addition, the connection portion 160b of the first conductive path unit 140b abuts on the connection portion of the second conductive path unit arranged on the right side of the second conductive path unit 240b in FIG. 4 to connect the second conductive path unit 240a. The portion 260a abuts on a connection portion of the first conductive path unit arranged on the left side of the first conductive path unit 140a in FIG. Note that, in the arrangement direction of the solar cell group 302, the connection portions of the first conductive path units and the second conductive path units corresponding to the solar cells arranged at both ends in the arrangement direction are outside the solar cell group 302. It contacts with an unillustrated extraction electrode (terminal bar) arranged on the side. In this way, wiring in the solar cell module 300 is realized using the first conductive portion 130 of the first sealing sheet 110 and the second conductive portion 230 of the second sealing sheet 210. The general construction of the solar cell module 300 can be implemented based on the common general technical knowledge in the technical field, and does not characterize the present invention.

  The above configuration is excellent in wiring workability of the solar battery cell as compared with a conventional wiring method (typically a method performed using solder or the like). Moreover, since it is excellent also in an intensity | strength surface, troubles, such as a disconnection resulting from the stress of a sealing sheet etc., are prevented, for example. Furthermore, since the electrical connection does not require soldering, it is possible to avoid problems (typically, cell warpage or cracking, characteristic deterioration, flux contamination) due to soldering. The fact that solder bonding is not required also brings advantages to the solar cell structure. Specifically, it is preferable to provide an aluminum electrode (back surface electrode) on the entire surface of the back surface of the solar battery cell from the viewpoint of a BSF (Back Surface Field) effect and the like. However, since aluminum is inferior in solder jointability, a silver electrode having excellent solder jointability is usually disposed at a joint location with metal wiring. That is, as the back electrode of the solar battery cell, an aluminum electrode and a silver electrode are usually used in combination. According to the technology disclosed herein, the electrical connection on the back surface of the solar battery cell is realized only by contacting the back electrode (aluminum electrode) on the back surface and the second conductive path unit of the second sealing sheet. Therefore, solder bonding on the back surface of the solar battery cell is not necessary. Therefore, by adopting the technology disclosed herein, a solar cell module having a structure in which the back electrode of the solar cell does not substantially contain a silver electrode can be realized. This configuration has significant advantages in cost reduction and productivity improvement.

<< Second Embodiment >>
FIG. 5 is a top view schematically showing the main part of the second sealing sheet according to the second embodiment.

  The second sealing sheet according to the second embodiment has basically the same configuration as the second sealing sheet according to the first embodiment except for the second conductive path unit. Therefore, in this embodiment, the second conductive path unit will be mainly described, and description of other points will be omitted.

  As shown in FIG. 5, the number of conductive lines 255a in the second conductive path unit 240a of the second sealing sheet 210 is the same as the number of conductive lines 155a in the first conductive path unit 140a of the first sealing sheet 110. However, the width of the conductive line 255a is larger than the width of the conductive line 155a. The conductive lines 255b in the second conductive path unit 240b are configured in the same manner as the conductive lines 255a, and the number of the conductive lines 255b is the same as the number of the conductive lines 155b in the first conductive path unit 140b, but the width is the conductive line 155b. Greater than the width of Also with this configuration, the wiring workability and power generation efficiency of the solar cell module are improved as in the first embodiment. Note that the width of the conductive lines 255a and 255b is preferably 1.2 times or more (more preferably 1.5 times or more, more preferably 2 times or more) the width of the conductive lines 155a and 155b, and is approximately 50 times. It is appropriate to make it not more than twice (for example, not more than 35 times), preferably not more than 30 times, more preferably not more than 20 times.

«Third embodiment»
FIG. 6 is a top view schematically showing the main part of the second sealing sheet according to the third embodiment.

  The second sealing sheet according to the third embodiment has basically the same configuration as the second sealing sheet according to the first embodiment except for the second conductive path unit. Therefore, in this embodiment, the second conductive path unit will be mainly described, and description of other points will be omitted.

  As shown in FIG. 6, the second conductive path unit 240 a (typically, the solar cell contact portion 250 a thereof) of the second sealing sheet 210 is formed on the first surface 210 </ b> A of the second sealing sheet 210. The battery cell facing region (solar cell back surface facing region) 205a is disposed in almost the entire region (for example, 80% or more, typically 90 to 100% of the area of the solar cell facing region 205a). Further, the second conductive path unit 240a protrudes from the solar cell facing region 205a to the solar cell non-facing region 207, and has a connection portion 260a at the protruding portion. This connection portion 260a is continuous with the solar cell contact portion 250a in the solar cell facing region 205a, and the arrangement direction of the solar cells 305a and 305b from the solar cell contact portion 250a (therefore, the solar cell facing region). 205a and 205b (in the direction of arrangement). The second conductive path unit 240b is configured similarly to the second conductive path unit 240a. In this embodiment, a metal sheet (specifically, a metal foil) is used as the second conductive path units 240a and 240b. As the metal sheet, those described later can be used. Further, the second conductive path units 240a and 240b in this embodiment have a rectangular shape when viewed from above. Also with this configuration, the wiring workability and power generation efficiency of the solar cell module are improved as in the first embodiment.

  In each of the above embodiments, the number of conductive path units (including the first conductive path unit and the second conductive path unit; the same applies hereinafter) is the number of the first sealing sheet and the second sealing sheet. However, the technique disclosed herein is not limited to this. The number of conductive path units in one sealing sheet basically corresponds to the number of solar cells sealed by the sealing sheet. For example, when a solar cell module is constructed by sealing a single solar cell with a pair of sealing sheets and connecting a plurality of this configuration (that is, a configuration in which the solar cells are sandwiched between a pair of sealing sheets). The number of conductive path units provided in one sealing sheet is one. On the other hand, when a plurality of solar cells are sealed with a pair of sealing sheets and batch wiring is performed, the number of conductive path units provided in one sealing sheet corresponds to the number of solar cells. 5 or more (for example, 30 or more, typically 50 or more), and may actually be about 50 to 60. Alternatively, a plurality of solar cells (for example, 2 to 20 solar cells arranged in a line at intervals) are sandwiched between a pair of sealing sheets, and a plurality (about 2 to 10) of this configuration is combined. It is also possible to construct a solar cell module.

  In each of the above embodiments, each of the first conductive path units constituting the first conductive portion has a plurality of conductive lines extending linearly. However, the technology disclosed herein is limited to this. Alternatively, one first conductive path unit may have one conductive line, the conductive line may extend in a curved line, and are not parallel to each other (for example, non-contact with each other) Parallel).

  Further, the second conductive portion and the second conductive path unit are not limited to the shapes, structures, and the like of the above embodiments. When a sealing sheet with a conductive portion is applied to a solar cell module, various shapes, structures, and the like that can realize wiring of solar cells using the second conductive portion can be employed. For example, the shape of the second conductive part and the second conductive path unit may be curved or annular. For example, the second conductive portion may have a pattern such as a lattice shape or a shape in which a plurality of rings are connected. Therefore, when the second conductive portion has the second conductive path unit and further has the solar cell contact portion and the connection portion, they have various shapes as long as the effects of the technology disclosed herein can be realized. And typically have various shapes and the like according to the pattern of the second conductive portion. For example, when the second conductive path unit has a conductive line, the conductive line may extend in a curved shape. When one second conductive path unit has a plurality of conductive lines, the plurality of conductive lines may be separated from each other, may be in contact with each other, or may be non-parallel (for example, cross each other), Alternatively, they may be non-parallel so as not to contact each other. The second conductive path unit may have a rectangular shape covering the entire back surface of the solar battery cell as in the third embodiment.

  Further, the number of conductive lines in one conductive path unit is not limited to the number in the first and second embodiments, for example. The number of conductive lines in one conductive path unit is preferably 2 or more (typically 2 to 20, more preferably 4 to 12, more preferably 6 to 10), or one There may be.

  The width of the conductive lines in the first conductive path unit (each width in the case of having a plurality of conductive lines) is preferably 30 μm or more, more preferably from the viewpoint of reduction of current collection loss, strength, handling properties and workability. Is 100 μm or more, more preferably 500 μm or more. The width is preferably 1500 μm or less, more preferably 1200 μm or less, and still more preferably 1000 μm or less from the viewpoint of reducing shadow loss. In addition, the said width | variety points out the length (width) orthogonal to the longitudinal direction of a conductive wire, as shown with the code | symbol W in FIG. When the second conductive path unit has a conductive line as in the first and second embodiments, the width of the conductive line of the second conductive path unit can be preferably selected from the above range.

  The height (thickness, height indicated by the symbol H in FIG. 2) of the conductive wire in the first conductive path unit is 10 μm or more (for example, 50 μm or more, for example) from the viewpoint of conductivity, strength, handling property, and workability. (Typically, it is preferably about 200 μm or more). The height is preferably about 1000 μm or less (for example, 500 μm or less, typically 300 μm or less) from the viewpoint of stability or the like. When the second conductive path unit has a conductive line as in the first and second embodiments, the height of the conductive line of the second conductive path unit can be preferably selected from the above range.

  When the first conductive path unit has two or more conductive lines, the distance between the conductive lines is preferably 0.1 cm or more, more preferably 0.8 cm or more, from the viewpoint of reduction of shadow loss, etc. Preferably it is 1.5 cm or more. The distance is preferably less than 4.0 cm, more preferably less than 3.0 cm, and even more preferably 2.5 cm or less from the viewpoint of reducing current collection loss. In addition, the said space | interval is a pitch and points out the distance between the centerlines in the width direction of a conductive wire. When the second conductive path unit has a plurality of conductive lines as in the first and second embodiments, the interval between the conductive lines of the second conductive path unit can be preferably selected from the above range.

  In addition, the shape and structure of the connection portion constituting the conductive path unit is not limited to the shape of each of the above embodiments, and the connection function with other wiring members (other conductive path units, extraction electrodes, etc.) is exhibited. Various arrangement states and shapes can be taken within the range. For example, the connecting portion may be the solar cell non-facing region portion in a shape in which the solar cell contact portion extends to the solar cell non-facing region as in the third embodiment.

  When the connection part in the conductive path unit has a shape extending linearly (also referred to as a band shape), the width of the connection part is preferably 0.1 cm or more from the viewpoint of wiring workability of the solar cell module, and more Preferably it is 0.3 cm or more, more preferably 0.5 cm or more. The width is preferably 2 cm or less, more preferably 1.5 cm or less, and further preferably 1.0 cm or less. In addition, the said width | variety points out the length (width | variety) orthogonal to the longitudinal direction of a connection part.

  In addition, the thickness (height) of the conductive portion (including the first conductive portion and the second conductive portion; the same applies hereinafter) is 0.01 to 1 mm from the viewpoints of conductivity, strength, handling properties, and workability. It is preferable to be about (for example, 0.02 to 0.5 mm, typically 0.05 to 0.3 mm). The thickness of the conductive path unit, conductive line, and connecting portion is preferably selected from the same range.

  Moreover, the solar cell module disclosed here is not limited to the structure of each said embodiment. For example, the number of solar cells arranged in the solar cell module may be one or more. According to the technology disclosed herein, a plurality of solar cells can be electrically connected in a lump. Therefore, the greater the number of solar cells, the greater the effect of improving the wiring workability. For example, when a plurality of solar cells are configured as a solar cell group arranged in a line, the number of cells in the solar cell group is preferably 3 or more, more preferably 5 or more (for example, 7 -20, typically 8-12). Moreover, a photovoltaic cell group may be 2 or more rows (for example, 3-10 rows, typically 5-8 rows).

  Moreover, in each said embodiment, although the several photovoltaic cell was comprised as a photovoltaic cell group arranged in a row, the arrangement | sequence (arrangement | positioning) of a several photovoltaic cell is not limited to this, linear form, It may be a curvilinear, regular pattern, or irregular pattern. Moreover, the space | interval of a photovoltaic cell does not need to be constant.

  Furthermore, the electrical connection method between the first conductive portion and the second conductive portion in the solar cell module is not limited to the method of each of the above embodiments. The first conductive part and the second conductive part can be electrically connected by appropriately modifying a conventionally known wiring method.

≪Each component of sealing sheet with conductive part and solar cell module≫
Next, each element which comprises the sealing sheet with an electroconductive part and a solar cell module is demonstrated.

<Sealing resin layer>
The sealing resin layer disclosed herein (including the first sealing resin layer and the second sealing resin layer; the same applies hereinafter) is a sheet-like member formed from the sealing resin. The sealing resin layer may have insulating properties and translucency. For example, it may be a resin layer that can exhibit fluidity by heat or pressure. In this specification, “having insulation” means a specific resistance at 25 ° C. of 1 × 10 ⁶ Ω · cm or more (preferably 1 × 10 ⁸ Ω · cm or more, typically 1 × 10 ¹⁰ Ω). -Cm or more). In this specification, electric resistance (for example, specific resistance) means a value at 25 ° C. unless otherwise specified. Further, in the present specification, “having translucency” means that the total light transmittance defined by JIS K 7375: 2008 is 50% or more (preferably 80% or more, typically 95% or more). That means. In addition, the 2nd sealing resin layer does not need to have translucency.

  The sealing resin is preferably a thermosetting resin, and may be a resin before curing (before performing a thermosetting process such as a crosslinking process) in the encapsulating sheet with a conductive part. As the sealing resin, an ethylene-vinyl acetate copolymer (EVA) is preferably used from the viewpoints of translucency, workability, weather resistance, and the like. The sealing resin is an ethylene-vinyl ester copolymer typified by EVA, an ethylene-unsaturated carboxylic acid copolymer such as an ethylene- (meth) acrylic acid copolymer, or an ethylene- (meth) acrylic acid ester. An unsaturated carboxylic acid ester copolymer such as ethylene-unsaturated carboxylic acid ester copolymer such as polymethyl methacrylate may be used. Alternatively, fluoropolymers such as vinylidene fluoride resin and polyethylene tetrafluoroethylene; manufactured using low density polyethylene (LDPE), linear low density polyethylene (LLDPE, typically Ziegler catalyst, vanadium catalyst, metallocene catalyst, etc. Can be produced using polyethylene (PE) such as LLDPE), polypropylene (PP. For example, PP that can be produced using Ziegler catalyst, Phillips catalyst, metallocene catalyst, etc.), Ziegler catalyst, vanadium catalyst, metallocene catalyst, etc. Polyolefins such as ethylene / α-olefin copolymers and their modified products (modified polyolefins); Polybutadienes; Polyvinyl acetals such as polyvinyl formal, polyvinyl butyral (PVB resin), and modified PVB; Terephthalate (PET); polyimide; amorphous polycarbonate; siloxane sol - gel; polyurethane; polystyrene; polyether sulfone; polyarylate, epoxy resins, may be like; silicone resin; ionomers. These resins may be used alone or in combination of two or more. The sealing resin may contain various additives known in this field such as an ultraviolet absorber and a light stabilizer.

  Moreover, it is preferable to provide an adhesion improver on the surface of the sealing resin layer before forming the above-described conductive portion. By forming the conductive part on the surface of the sealing resin layer to which the adhesion improver is applied, the adhesion between the conductive part and the sealing resin layer is improved, and disconnection, displacement, and deformation of the conductive part are preferably performed. Can be prevented. When an EVA sheet is used as the sealing resin layer, a silane coupling agent is preferably used as an adhesion improver. Typically, the adhesiveness of the conductive part is improved by applying an adhesion improver to the surface of the sealing resin layer and then performing a heat treatment. In addition, the usage form of an adhesive improvement agent is not limited to application | coating, It is also possible to use it by including in the said sealing resin layer.

  The surface of the sealing resin layer not only can be provided with the above-mentioned adhesion improver, but also improves the adhesion between the sealing resin layer and the conductive part, suppresses deformation of the sealing resin layer, and stabilizes the conductive part. For the purpose of arrangement, an additional layer (for example, a resin layer such as an adhesive layer or a pressure-sensitive adhesive layer) can be arranged. In that case, the additional layer may be disposed between the sealing resin layer and the conductive portion. In addition, for the purpose of improving the adhesion and the like, various surface treatments such as corona treatment and atmospheric pressure plasma treatment can be performed alone or in combination. The surface treatment may be performed on the conductive portion.

  The thickness of the sealing resin layer is preferably about 100 to 2000 μm (for example, 200 to 1000 μm, typically 400 to 800 μm) from the viewpoint of the conductive part forming property, the solar cell sealing property, and the like.

<Conductive part>
The conductive part (including the first conductive part and the second conductive part. In addition, the solar cell contact part and the connection part of the first conductive path unit and the second conductive path unit may be included. The same shall apply hereinafter). Typically includes a conductive material. The conductive portion is formed, for example, by applying a conductive paste as a conductive material. Thereby, a conductive path can be efficiently formed while reducing the number of parts. As the conductive paste, conductive components made of metal materials such as gold, silver, copper, aluminum, iron, nickel, tin, chromium, bismuth, indium, and alloys thereof, and conductive components made of non-metals such as carbon (hereinafter referred to as “conductive paste”) The same)) and a resin component such as polyester or epoxy resin can be used in a suitable solvent. Especially, it is preferable to use silver or copper as a conductive component from a viewpoint of temporal stability. Specific examples of the conductive paste include silver paste (trade name “Pertron K-3105”, manufactured by Pernox, conductive component: Ag, resin component: polyester resin, specific resistance: 6.5 × 10 ⁻⁵ Ω · cm). Is mentioned. The specific resistance of the conductive paste at 25 ° C. is about 5 × 10 ⁻⁴ Ω · cm or less (for example, 1 × 10 ⁻⁴ Ω · cm or less, typically 5.0 × 10 ⁻⁷ Ω · m or less). Preferably there is. The specific resistance of the conductive component constituting the conductive paste is preferably 5.0 × 10 ⁻⁷ Ω · m or less.

  The conductive portion can be formed by applying a conductive paste to the surface of the sealing resin layer using a known dispenser. Alternatively, the conductive paste is applied to the surface of a peelable support (for example, a sheet-like release liner), not to the surface of the sealing resin layer, and the conductive portion having a predetermined pattern on the surface of the peelable support Then, the conductive portion may be formed on the surface of the sealing resin layer by transferring the conductive portion to the surface of the sealing resin layer.

  Moreover, you may use a conductive sheet as a connection part which comprises the conductive path unit (a 1st conductive path unit and a 2nd conductive path unit are included) of a conductive part. The conductive path unit according to a preferred embodiment is such that the solar cell contact portion is formed of the conductive paste as described above, and the conductive sheet serving as the connection portion is connected to the solar cell contact portion formed of the conductive paste. It is arranged to do. The conductive sheet may be selected from a conductive resin sheet in which the above-described conductive component is blended in a resin, or a metal sheet (for example, a metal foil) made of a metal such as copper or aluminum, an alloy, or the like. Especially, since it is excellent in alignment and workability | operativity, it is preferable to use the electroconductive adhesive sheet which has adhesiveness to at least one surface (typically both surfaces) as an electroconductive sheet.

  Examples of the conductive adhesive sheet include a conductive adhesive sheet, a hot melt type, a thermosetting type, a drying type, a moisture curing type, a two-component reaction curing type, an ultraviolet (UV) curing type, an anaerobic type, and a UV anaerobic type. A conductive adhesive sheet can be used. As the adhesive component of the adhesive sheet, urethane, acrylic, epoxy and other adhesive components can be used. Among these, a conductive pressure-sensitive adhesive sheet that does not require a heating operation and is excellent in handleability is particularly preferable. Typically, a substrate-less pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer (for example, an acrylic pressure-sensitive adhesive layer) containing about 3 to 70% by weight of the above-described conductive component (more preferably, a silver filler), copper foil or aluminum foil A pressure-sensitive adhesive sheet in which the above-mentioned pressure-sensitive adhesive layer is formed on at least one surface (typically both surfaces) of a metal foil substrate such as is preferably used. The pressure-sensitive adhesive layer may contain a tackifier, a crosslinking agent, and other additives depending on the purpose. As said adhesive sheet, what is described, for example in Unexamined-Japanese-Patent No. 2012-7093 can be used preferably. Alternatively, the conductive pressure-sensitive adhesive sheet is a double-sided pressure-sensitive adhesive sheet in which a non-conductive pressure-sensitive adhesive layer is formed on both surfaces of the above-mentioned conductive base material, and the conductive base material is partially the surface of the pressure-sensitive adhesive layer. It may be a conductive pressure-sensitive adhesive sheet exposed to the surface. Examples of such a conductive pressure-sensitive adhesive sheet include those described in JP-A-8-185714.

  In another preferred embodiment, the conductive portion is formed by hot-melt coating a metal material (typically an alloy) having a low melting point (for example, a melting point of 300 ° C. or lower, preferably 250 ° C. or lower). Specifically, a low melting point alloy (for example, “SnBi solder” manufactured by Arakawa Chemical Industries, Ltd., melting point 139 ° C.) is used on the surface of the sealing resin layer using a commercially available hot melt dispenser (for example, manufactured by Musashi Engineering Co., Ltd.). A conductive part can be formed by coating. The low melting point metal material may be applied not to the surface of the sealing resin layer but to the surface of a peelable support (for example, a release liner). In that case, the conductive part can be formed on the surface of the sealing resin layer by transferring the conductive part formed so as to have a predetermined pattern on the surface of the peelable support to the surface of the sealing resin layer. Note that the same configuration as described above can be obtained by employing various printing methods such as screen printing.

  In another preferred embodiment, a metal material such as gold, silver, copper, aluminum, iron, nickel, tin, chromium, bismuth, indium, or an alloy thereof can be preferably used as the material constituting the conductive portion. Among these, silver, copper, aluminum, and iron are more preferable, and copper and aluminum are more preferable. Conductive paths composed essentially of metal have the advantage of lower resistance. As a typical example, there is a conductive portion composed of a conductive path unit in which the solar cell contact portion is a conductive wire made of a metal wire and the connection portion is a metal sheet (typically a metal foil). As an example of the metal wire, one provided with a plating coating such as tin (Sn) or silver (Ag) can be given. The plating thickness may be about 10 μm or less (for example, 3 μm or less). As said metal sheet (typically metal foil), what gave at least 1 type of surface treatment of a roughening process, a rust prevention process, and an adhesive improvement process may be used preferably. Suitable examples of the metal sheet include copper foil (in particular, electrolytic copper foil).

  The sealing sheet having the conductive part (including the first sealing sheet and the second sealing sheet) is produced, for example, as follows. That is, first, the conductive line and the connecting portion of the solar cell contact portion are fixed to produce a conductive path unit (also referred to as a conductive member). Then, by disposing the produced conductive path unit on the surface of the sealing resin layer (in the case where there are a plurality of conductive path units, by disposing each at an interval), the encapsulating sheet with the conductive portion is produced. Is done. Note that the sealing resin layer and the conductive portion may be bonded using a known or common bonding means such as a pressure-sensitive adhesive or an adhesive.

  As a method for fixing the solar cell contact portion (for example, conductive wire) and the connection portion in the conductive path unit, it is preferable to employ welding. As the welding method, conventionally known various types of welding can be employed. For example, arc welding, resistance welding, laser beam welding, electron beam welding, and ultrasonic welding can be preferably employed. Or it is also possible to employ | adopt the fixing method by plating joining and a conductive adhesive.

  As another preferred example in which the conductive portion is made of a metal material, a configuration in which the conductive path unit is made of a metal wire can be given. As a metal wire, the above-mentioned thing can be used preferably. For joining metal wires, various joining methods such as the above-described welding can be employed.

  Alternatively, the conductive path unit may be formed from a patterned metal sheet. Such a conductive path unit can integrally form the solar cell contact portion and the connection portion by etching the metal sheet. Specifically, a resist is attached to the surface of a metal sheet (typically a metal foil), and a predetermined resist pattern is formed by applying a photolithography technique. Next, the metal sheet is patterned using a known or conventional etching solution. Thus, a conductive sheet unit with a conductive part can be obtained by forming a conductive path unit and disposing it on the surface of the sealing resin layer. A similar configuration can be obtained by various vapor deposition methods.

  Alternatively, the conductive path unit may be formed from a metal sheet (mesh sheet) having a mesh structure. The mesh sheet typically has a mesh structure (mesh shape) in which a plurality of metal wires are arranged vertically and horizontally. More specifically, the conductive path unit includes a plurality of metal lines (vertical lines) arranged along one direction and a plurality of metals arranged in a direction intersecting (typically substantially orthogonal) with the vertical lines. A network structure composed of lines (horizontal lines). In each of the vertical and horizontal lines, the plurality of metal lines are spaced apart and are typically substantially parallel. The mesh-shaped wire diameter and mesh size can be set to be within the above-described ranges of the width and spacing of the conductive wires and the width of the connecting portion.

  Alternatively, the conductive line of the conductive path unit may be formed of a mesh material containing a conductive material (for example, a metal such as copper). The mesh material may be a composite material of a metal wire and a resin fiber (typically a transparent resin fiber). The metal wires are arranged in stripes, and the resin fibers are arranged in the same direction as the metal wires and in a direction intersecting with the metal wires, thereby forming a mesh structure. The mesh material can be produced by weaving metal wires into resin fibers so that the metal wires are arranged in a predetermined direction. In this case, it is preferable to use a resin fiber for the weft and a metal wire and a resin fiber for the warp. By disposing the mesh material on the surface of the sealing resin layer, a sealing sheet with a conductive part can be obtained. The resin fiber is preferably a material having high transparency and excellent insulating properties. Specific examples include a mesh material in which the metal wire is a copper wire and the resin fiber is a PET fiber having excellent transparency. The mesh material is available, for example, from NBC Meshtec.

  The connection portion constituting the conductive path unit may have a single layer structure or a multilayer structure. Further, when the solar cell is sandwiched between the first sealing sheet and the second sealing sheet, an additional conductive connection member is provided between the connection part of the first conductive path unit and the connection part of the second conductive path unit. May be arranged. As such a conductive connection member, an appropriate material can be selected and used from the materials that can be used as the connection portion. Preferred examples thereof include a metal sheet (specifically, a metal foil) and a conductive adhesive sheet. Thereby, when the solar cell is sandwiched between the first sealing sheet and the second sealing sheet, the thickness of the laminated portion of the connection portion of the first conductive path unit and the connection portion of the second conductive path unit increases. In addition, the contact state between the connection portion of the first conductive path unit and the connection portion of the second conductive path unit is improved, and the current collection efficiency is improved. The shape of the conductive connection member is not particularly limited, and is preferably the same shape as the connection portion of the first conductive path unit and the connection portion of the second conductive path unit.

  The connecting portion constituting the conductive path unit may be a continuous layer (conductive layer) in a band shape as described above, but may be an intermittent layer. For example, the connecting portion may have an intermittent band shape, or may be arranged in a dot shape (also referred to as a granular shape). The dot shape is typically granular, and may be, for example, a spherical shape such as a true spherical shape or a flat spherical shape. The connection portion having such a shape can be formed by using, for example, the conductive paste or the low melting point metal material.

  The connection part of the conductive path unit is arranged at a distance from the solar battery cell in the solar battery module. However, in order to prevent short circuit with the solar battery cell reliably, the connection part between the connection part and the solar battery cell. It is preferable to provide an insulating part. For example, when a strip-shaped connection portion is disposed between two adjacent solar cells, it is preferable to provide insulating portions at both ends in the width direction of the connection portion. The insulating part can be provided by applying a known insulating resin material. Or it can also provide by coat | covering well-known insulating resin sheets, such as a polyimide tape. The product name “cellophane tape” manufactured by 3M may be used as the insulating portion.

  In the case where the connecting portion is formed in a strip shape with the above-described conductive paste or low melting point metal material, the advantage of providing insulating portions at both ends in the width direction is particularly great. In such a configuration, the connecting portion and the insulating portion may be formed by separately painting using a dispenser having a three-neck nozzle. As the conductive layer forming material, a material similar to the material capable of forming the conductive portion described above may be used. As the insulating layer forming material, a conventionally known resin paste or the like whose main component is a resin such as polyimide or polyester may be used.

  As described above, the solar battery cell contact portion and the connection portion of the conductive path unit may be integrally formed, for example, by the same method, or after being formed by different methods, they are connected to form a conductive path unit. May be used.

<Solar cell>
The type of the solar battery cell to be used is not particularly limited, and for example, a single crystal type or a polycrystalline type Si cell is suitable. The crystalline Si cell may be a p-type cell (a cell in which n-type is added to a p-type substrate) or an n-type cell (a cell in which p-type is added to an n-type substrate). Further, the solar battery cell may be an amorphous Si cell, a compound solar battery, an organic solar battery cell or the like. The shape is not particularly limited, and may be a wafer having a substantially rectangular plane, or may be a belt shape. The thickness of the solar battery cell is preferably about 0.5 mm or less, more preferably about 0.3 mm or less (for example, about 180 to 200 μm), and further preferably about 160 μm or less from the viewpoint of lightness and the like.

<Surface covering member>
As the surface covering member, various materials having translucency can be used. The surface covering member is a glass plate, a fluororesin sheet such as tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride resin, chlorotrifluoroethylene resin, acrylic resin, polyethylene terephthalate It may be a resin sheet composed of a material such as polyester such as (PET) or polyethylene naphthalate (PEN). For example, a flat plate member or a sheet member having a total light transmittance of 70% or more (for example, 90% or more, typically 95% or more) can be preferably used. The total light transmittance may be measured according to JIS K 7375: 2008. The thickness of the surface covering member is preferably about 0.5 to 10 mm (for example, 1 to 8 mm, typically 2 to 5 mm) from the viewpoint of protection and lightness.

<Backside coating member>
As the back surface covering member, a flat plate member or a sheet member made of various materials exemplified as the material of the surface covering member is preferably used. Especially, it is more preferable to use polyester, such as PET and PEN, as a back surface covering member forming material. Or as a back surface covering member, you may use the metal sheet (for example, aluminum plate) which has corrosion resistance, resin sheets, such as an epoxy resin, and composite sheets, such as a silica vapor deposition resin. The thickness of the back surface covering member is preferably about 0.1 to 10 mm (for example, 0.2 to 5 mm) from the viewpoint of handleability and lightness. In addition, the back surface covering member may not have translucency.

The matters disclosed by this specification include the following.
(1) a plurality of solar cells arranged at intervals;
A first sealing sheet covering the surfaces of the plurality of solar cells;
A second sealing sheet covering the back surface of the plurality of solar cells,
The first sealing sheet includes a first sealing resin layer and a first conductive part that constitutes a part of the first surface of the first sealing sheet,
The second sealing sheet includes a second sealing resin layer and a second conductive part that constitutes a part of the first surface of the second sealing sheet,
The first conductive part is in contact with the surface of one of the two adjacent solar cells among the plurality of solar cells,
The second conductive portion is in contact with the back surface of the other solar cell of the two adjacent solar cells, and the first conductive portion and the second conductive portion are configured to be electrically connected. A solar cell module.
(2) The first conductive portion has a portion that protrudes from a region located between two adjacent solar cells so as to face the surface of one of the adjacent two solar cells. Are arranged so that
The second conductive portion is disposed so as to face the back surface of the other solar cell of the two adjacent solar cells and to have a portion that protrudes from a region located between the two adjacent solar cells. The solar cell module according to (1) above.
(3) Each of the first conductive portion and the second conductive portion is composed of at least one conductive path unit,
The solar cell according to (1) or (2), wherein one conductive path unit includes a solar cell contact portion located in the solar cell facing region and a connection portion located in the solar cell non-opposing region. Battery module.
(4) In one conductive path unit, the solar cell contact portion has a shape extending toward the connection portion, and the connection portion is connected to one end of the solar cell contact portion. Solar cell module.
(5) In one conductive path unit, the solar cell contact part is composed of a plurality of conductive lines arranged at intervals, and the connection part extends in a direction intersecting with the longitudinal direction of the conductive line. The solar cell module according to (4), wherein the solar cell module has a strip shape connected to one end of the conductive wire.
(6) The protruding portion of the first conductive portion (typically, the connecting portion of the first conductive path unit) and the protruding portion of the second conductive portion (typically, the connecting portion of the second conductive path unit) Is a solar cell module according to (2), which is directly or indirectly connected (typically abutting).

(7) preparing a plurality of solar cells;
Obtaining a first encapsulating sheet comprising: a first encapsulating resin layer; and a first conductive portion constituting a part of the first surface of the first encapsulating sheet;
Obtaining a second encapsulating sheet comprising: a second encapsulating resin layer; and a second conductive portion constituting a part of the first surface of the second encapsulating sheet;
A step of sandwiching a plurality of solar cells between the first sealing sheet and the second sealing sheet (typically, in this step, the plurality of solar cells are arranged at intervals, and the plurality of solar cells The first conductive portion is brought into contact with the surface of one of the two adjacent solar cells, and the second conductive portion is brought into contact with the back surface of the other of the two adjacent solar cells, And the first conductive portion and the second conductive portion are electrically connected.);
A method for manufacturing a solar cell module, comprising:
(8) First so that the first conductive portion faces the surface of one of the two adjacent solar cells and protrudes into a region located between the two adjacent solar cells. Including a step of arranging a sealing sheet,
The second encapsulating sheet so that the second conductive portion faces the back surface of the other solar cell of the two adjacent solar cells and protrudes into a region located between the two adjacent solar cells. The manufacturing method as described in said (7) including the process of arrange | positioning.
(9) Each of the first conductive portion and the second conductive portion is composed of at least one conductive path unit,
(7) or (8), wherein one conductive path unit is formed to have a solar cell contact portion located in a solar cell facing region and a connection portion located in a solar cell non-opposing region. The manufacturing method as described in.
(10) The protruding portion of the first conductive portion (typically, the connecting portion of the first conductive path unit) and the protruding portion of the second conductive portion (typically, the connecting portion of the second conductive path unit) Are directly or indirectly connected (typically abutting) to each other.

  Examples of the present invention will be described below, but the present invention is not intended to be limited to those shown in the specific examples. In the following description, “parts” and “%” are based on weight unless otherwise specified.

<Reference experiment 1>
Prepare 2 sheets of EVA sheet (trade name “EVASC Fast Cure Type”, Sanvik) manufactured by Sanvik Co., Ltd.) with a thickness of 450 μm cut into 36cm × 18cm, and wire a silane coupling agent (Shin-Etsu Chemical Co., Ltd.) It was applied using a bar and dried at 60 ° C. for 2 minutes. Conductive paste (trade name “Pertron K-3105”, manufactured by Pernox, conductive component: Ag, resin component: polyester resin, specific resistance: 6.5 × 10 ^{−5) on} the silane coupling agent application surface of each EVA sheet. Ω · cm) is applied using a dispenser (manufactured by Musashi Engineering Co., Ltd.), so that two EVA sheets having conductive patterns (thickness of each conductive line: 200 μm) as shown in FIG. Was made.

  A back sheet (trade name “KOBATEC PV KB-Z1-3”, manufactured by Kobayashi Co., Ltd.) having a thickness of 200 μm cut to 36 cm × 18 cm is prepared as a back surface covering member, and the conductive part formation EVA prepared above is prepared thereon. One of the sheets was installed such that the conductive part forming surface was the upper surface. On the EVA sheet, two crystalline Si solar cells (manufactured by Q CELLS) are arranged with an interval, and a long conductive adhesive sheet (manufactured by NITTO DENKO CO., LTD.) Is placed between the two cells. Was installed such that the longitudinal direction thereof was perpendicular to the arrangement direction of the two cells. A terminal bar (trade name “A-SPS”, manufactured by Hitachi Cable, Ltd.) having a width of 6 cm was disposed on both outer sides of the two cells in the arrangement direction of the solar cells. On top of that, the conductive part-formed EVA sheet prepared above was placed so that the conductive part forming surface was the lower surface. The two terminal bars are respectively arranged so as to come into contact with the conductive portion protruding outward from each cell. Further, a 3.2 mm thick glass plate (manufactured by Asahi Glass Co., Ltd., white plate heat-treated glass) is placed thereon as a surface coating member, and then a commercially available laminator (manufactured by NPC Co.) is used at 140 ° C. and 70 kPa for 15 minutes. And a test solar cell module having a cross-sectional structure as shown in FIG. 4 (however, the number and thickness of the conductive wires in the upper and lower sealing sheets are the same).

  This test module was installed in a solar simulator (trade name “YSS-50”, manufactured by Yamashita Denso Co., Ltd.), and the maximum amount of power was measured. The conversion efficiency (power generation efficiency) obtained based on the irradiance was 6.3%. From this result, it can be seen that by applying the technique disclosed herein, the wiring workability is improved while realizing a power generation efficiency of a predetermined level or more.

<Reference experiment 2>
(Conductive member)
A 75 μm thick copper foil was cut into a size of 16 cm × 0.5 cm. As the copper foil, an electrolytic copper foil (electrolytic copper foil for rigid substrate, purity of 99.8% or more (before surface treatment)) was used. The electrolytic copper foil is subjected to roughening treatment, rust prevention treatment, and adhesion improving treatment using zinc, chromium, and arsenic. Next, a silver (Ag) -coated wire (width 800 μm, thickness 250 μm) was prepared, and one end thereof was placed on the copper foil and fixed by welding. The Ag-coated wire was fixed so that the longitudinal direction thereof was orthogonal to the longitudinal direction of the copper foil. As the Ag-coated wire, a copper (Cu) wire coated with Ag was used. The above-described fixing operation of the Ag-coated wire was repeated along the longitudinal direction of the copper foil to obtain a comb-shaped conductive member in which four or eight Ag-coated wires were arranged.
Further, a comb-shaped conductive member in which four, eight, or fifteen Sn-coated wires were arranged was obtained in the same manner as above except that the Ag-coated wire was changed to a tin (Sn) -coated wire (width: 500 μm). The conductive member has basically the same structure as the first conductive path unit shown in FIG. 1, but the number of wires does not match.
Further, a metal foil (Sn—Cu foil) was prepared as a conductive member. This conductive member has the same shape and structure as the second conductive path unit shown in FIG.

(Sealing resin)
A 450 μm thick EVA sheet (trade name “EVASKY”, manufactured by Bridgestone) was cut into 18 cm × 18 cm to prepare a sheet-shaped sealing resin (sealing resin layer).

(Seal sheet with conductive part)
After surface-treating one surface of the sheet-shaped sealing resin, the conductive member obtained above was disposed on the surface-treated surface to obtain a sealing sheet with a conductive part. For the surface treatment, corona treatment using a corona treatment device (for example, manufactured by Kasuga Denki Co., Ltd.), atmospheric pressure plasma treatment using an atmospheric pressure plasma processing device (for example, manufactured by Sekisui Chemical Co., Ltd.), and a silane coupling agent (trade name “KBM”). -503 "(manufactured by Shin-Etsu Chemical Co., Ltd.) is applied alone or in combination.

(Solar cell module)
A back sheet having a thickness of 200 μm (trade name “KOBATEC PV KB-Z1-3”, manufactured by Kobayashi Co., Ltd.) was prepared, cut to 18 cm × 18 cm, and a back coating member was prepared. This back surface covering member was placed, and the sealing sheet with a conductive part (second sealing sheet) produced above was placed thereon so that the conductive part forming surface was the upper surface. On the second sealing sheet, a Si-based solar battery cell (single crystal cell, manufactured by Q CELLS Co., Ltd.) having three bus bar electrodes (1.5 mm × 0.2 mm solder-coated copper wire) fixed on the front surface thereof Is disposed so as to abut on the second conductive portion (specifically, a comb-shaped tooth portion) of the second sealing sheet. In addition, the said bus-bar electrode is being fixed to the said photovoltaic cell with the solder. Then, a copper terminal bar (trade name “A-SPS”, manufactured by Hitachi Cable, Ltd.) having a width of 6 cm was installed on both sides of the solar battery cell as an extraction electrode. On top of that, the sheet-shaped sealing resin prepared above was installed. Further, a 3.2 mm thick glass plate (manufactured by Asahi Glass Co., Ltd., white plate heat-treated glass) is disposed thereon as a surface covering member, and then a commercially available laminator (manufactured by NPC Co.) is used at 150 ° C. and 100 kPa for 5 minutes. Was laminated and cured for 15 minutes. Furthermore, the solar cell module for a test was constructed by performing a drying treatment at 150 ° C. for 15 minutes using a commercially-available air constant temperature thermostat (manufactured by Yamato Scientific Co., Ltd.).
As the test solar cell module, a module is prepared in which the number of conductive wires (wires) in the second conductive path unit in the second encapsulating sheet is changed to 4 and 8, respectively, and the number of Sn-covered wires is changed to 15 did. Moreover, the solar cell module for a test using the 2nd sealing sheet which used the 2nd conductive path unit as metal foil was prepared.

  In addition, for comparison, solar cells that are wired with three bus bar electrodes on both the front and back surfaces are prepared, the solar cells with the bus bar electrodes are used, and both upper and lower sheet-shaped sealing resins (trade name “EVASKY”, Bridgestone) A test solar cell module was constructed in the same manner as described above except that 18 cm × 18 cm) was used. The bus bar electrode is also fixed to the solar battery cell with solder.

(Evaluation)
For the obtained test solar cell module, the series resistance Rs (Ω / cm ² ) was measured. The results are shown in Table 1.

  As shown in Table 1, it can be seen that the series resistance tends to decrease as the number of conductive wires on the back side of the solar battery cell increases. Moreover, when metal foil was arrange | positioned in the substantially whole back surface of a photovoltaic cell, series resistance reduced greatly. In this experiment, since the number of bus bar electrodes on the surface side of the solar battery cell was constant (three), it was shown that the series resistance can be reduced without increasing the shadow loss.

<Example>
As the solar battery cell, a Si solar battery cell (manufactured by Q Cells Inc., single crystal cell) in which the bus bar electrode was not fixed was used. Moreover, the 2nd sealing sheet which has a 2nd conductive path unit in which 15 Ag covering wires (conducting wire) were arranged was used as a 2nd sealing sheet. Moreover, the sheet-shaped sealing resin arrange | positioned on the upper surface of a photovoltaic cell was changed into the 1st sealing sheet which has the 1st conductive path unit with which eight Ag coating | coated wires (conductive wire) were arranged. As the Ag-coated wire, a wire (width 800 μm, thickness 250 μm, rectangular cross-section) obtained by coating a copper wire with Ag was used. Other than that, the test solar cell module having the cross-sectional structure schematically shown in FIG. The obtained test for a solar cell module was measured series resistance Rs (Ω / cm ²⁾ in the same manner as described above, it was 1.97Ω / cm ^2.

  From the above results, an increase in shadow loss is achieved by using a sealing sheet with a conductive part as the sealing resin and increasing the area of the second conductive part of the second sealing sheet disposed on the back side of the solar battery cell. It can be seen that the series resistance on the back surface side can be lowered while preventing current collection, and the current collection efficiency can be improved efficiently. Moreover, by using the sealing sheet with a conductive part, the bus bar electrode soldering step can be omitted, and the wiring workability can be greatly improved. In particular, in the above embodiment, since the conductive wire satisfying the ratio (H / W) of the cross-sectional shape of 1/2 or less was used as the conductive wire of the first sealing sheet, the arrangement of the first conductive path unit is stable, In addition, the contact area with the solar battery cell is increased, which is considered to have contributed to improvement in wiring workability and power generation efficiency. It turns out that the solar cell module excellent in power generation efficiency is efficiently manufactured by using a pair of sealing sheet disclosed here.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

100 A pair of sealing sheets 110 First sealing sheet 110A First surfaces 105a and 105b of the first sealing sheet Solar cell facing region 107 Solar cell non-facing region 120 First sealing resin layer 130 First conductive portion 140a , 140b First conductive path units 150a, 150b Solar cell contact portions 155a, 155b Conductive lines 160a, 160b Connection portion 210 Second sealing sheet 210A First surface 205a, 205b of second sealing sheet Solar cell facing region 207 Solar cell non-facing region 220 Second sealing resin layer 230 Second conductive portion 240a, 240b Second conductive path unit 250a, 250b Solar cell contact portion 255a, 255b Conductive line 260a, 260b Connection portion 300 Solar cell module 302 Sun Battery cell group 305, 305a, 305b Cell 320 surface-coated member 330 backside covering member

Claims (8)

A pair of encapsulating sheets for encapsulating at least one solar cell in a solar cell module,
A first sealing sheet disposed on the surface side of the at least one solar battery cell;
A second sealing sheet disposed on the back side of the at least one solar cell;
With
The first sealing sheet includes a first sealing resin layer, and a first conductive part partially disposed on one surface of the first sealing resin layer,
The second sealing sheet includes a second sealing resin layer and a second conductive portion partially disposed on one surface of the second sealing resin layer,
The first conductive part has at least one first conductive path unit;
The first conductive path unit has at least one conductive line as a solar cell contact portion,
The conductive wire of the first conductive path unit has a ratio (H / W) of height (H) to width (W) of 1/2 or less,
The area of the second conductive part in the solar cell facing region on the surface of the second sealing sheet is larger than the area of the first conductive part in the solar cell facing region on the surface of the first sealing sheet. Sealing sheet. The second conductive part has at least one second conductive path unit;
The second conductive path unit has a plurality of conductive lines as solar cell contact portions,
2. The pair of sealing sheets according to claim 1, wherein the number of the conductive lines in the second conductive path unit is greater than the number of the conductive lines in the first conductive path unit. The second conductive part has at least one second conductive path unit;
The second conductive path unit has a conductive wire as a solar cell contact portion,
The pair of sealing sheets according to claim 1 or 2, wherein a width of the conductive line in the second conductive path unit is larger than a width of the conductive line in the first conductive path unit. The second conductive part has at least one second conductive path unit;
2. The pair of sealing sheets according to claim 1, wherein the second conductive path unit is disposed in substantially the entire region of the solar cell facing region on the surface of the second sealing sheet.   The pair of encapsulating sheets according to any one of claims 1 to 4, wherein the conductive lines of the first conductive path unit have a rectangular shape in a cross section perpendicular to the longitudinal direction of the conductive lines.   The pair of sealing sheets according to any one of claims 1 to 5, wherein a height of the conductive line in the first conductive path unit is 50 to 300 µm, and a width of the conductive line is 100 to 1200 µm. .   The pair of sealing sheets according to any one of claims 1 to 6, wherein in the first conductive path unit, the at least one conductive line is a plurality of conductive lines arranged at intervals. .   A solar cell module provided with an at least 1 photovoltaic cell and a pair of sealing sheet as described in any one of Claims 1-7.

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