JP2009081217A - Solar battery module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar battery module which can suppress a gas bubble from being confined in each gap between a resin bonding agent and the other member. <P>SOLUTION: The solar battery module 10 has structure (comprising first and second structures 45, 55) constituted by bonding conductors (comprising a bus-bar electrode 40 and a wiring material 5) to a resin layer 50. Each conductor has a plurality of grooves (first and second degassing paths 41, 51) communicatively continuous to the outside of structure from the bonding surface of the resin layer 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solar cell module in which a resin adhesive is disposed between a wiring material and a main surface of a solar cell.

  Solar cells are expected as a new energy source because they can directly convert clean and inexhaustible sunlight into electricity.

  Generally, the output per solar cell is about several watts. Therefore, when a solar cell is used as a power source for a house or a building, a solar cell module whose output is increased by connecting a plurality of solar cells is used. The solar cell module is configured by electrically connecting a plurality of solar cells arranged according to the arrangement direction to each other by a wiring material.

  The solar cell includes a photoelectric conversion unit that generates a photogenerated carrier by receiving light, a thin line electrode that collects the photo generated carrier from the photoelectric conversion unit, and a bus bar electrode that collects the photo generated carrier from the thin line electrode. The bus bar electrode is formed along the arrangement direction on the photoelectric conversion unit. The wiring member is connected to the bus bar electrode of one solar cell and the bus bar electrode of another solar cell adjacent to the one solar cell.

  Here, a technique has been proposed in which a wiring material is connected to a bus bar electrode using a resin adhesive that is thermoset at a temperature lower than the melting temperature of the solder (see, for example, Patent Document 1). Specifically, after a film-like resin adhesive and a wiring material are sequentially stacked on the bus bar electrode, the wiring material is thermocompression bonded to the bus bar electrode.

According to this, the wiring material can be connected to the bus bar electrode at a temperature lower than the soldering. Therefore, the influence which the temperature change at the time of connecting a wiring material has on a solar cell can be made small.
JP 2005-101519 A

  On the other hand, fine irregularities exist on the surfaces of the resin adhesive, the wiring material, and the bus bar electrode. For this reason, when the wiring member is connected to the bus bar electrode via the resin adhesive, a large number of minute bubbles are confined at the interface between the bus bar electrode and the resin adhesive and the interface between the wiring member and the resin adhesive. When such bubbles remain at each interface, the contact area between the members becomes small. For this reason, the adhesive force between members decreases and the contact resistance at each interface increases.

  Further, such bubbles repeatedly expand and contract due to temperature changes in the usage environment of the solar cell module. For this reason, peeling between members occurs, and the contact resistance at each interface further increases.

  As a result, there is a problem that the electrical characteristics of the solar cell module are deteriorated.

  Then, this invention is made | formed in view of said problem, and it aims at providing the solar cell module which can suppress that a bubble is enclosed between a resin adhesive and another member. To do.

  A first feature of the present invention relates to a solar cell module, wherein a plurality of solar cells are sealed between a light-receiving surface side protection member and a back surface side protection member, and the plurality of solar cells are arranged in the arrangement direction. An array of solar cell modules, in which a conductor extending along the arrangement direction has a structure bonded to a resin layer formed of a resin adhesive, and the conductor includes a conductor and a resin layer. It has a plurality of deaeration paths communicating from the adhesive surface to the outside of the structure, and the gist is that the resin adhesive is filled in the deaeration paths.

  Thus, a plurality of deaeration paths are formed in the conductor bonded to the resin layer. Accordingly, when the resin adhesive is thermocompression-bonded to the conductor, it is possible to promote deaeration of air sandwiched between the conductor and the resin adhesive or air dissolved in the resin adhesive. Specifically, the resin adhesive melted by heating is filled in the groove, whereby air is pushed out of the structure. Therefore, bubbles can be prevented from remaining at the interface between the conductor and the resin layer. As a result, an increase in contact resistance can be reduced.

  Moreover, since the resin adhesive is filled in the plurality of deaeration paths, the adhesive force between the conductor and the resin layer can be improved by a so-called anchor effect.

  The second feature of the present invention is related to the first feature of the present invention, wherein the conductor is a wiring material that electrically connects a plurality of solar cells, and the deaeration path is formed on the bonding material on the bonding surface. The gist of the present invention is that the groove has a shape extending from one end of the wiring member to the other end of the wiring member along an orthogonal direction substantially orthogonal to the arrangement direction.

  The third feature of the present invention relates to the second feature of the present invention, and is summarized in that the wiring member has a curved surface that curves toward the inside of the groove in the boundary region between the bonding surface and the groove.

  The fourth feature of the present invention relates to the second feature of the present invention, and is summarized in that the depth of the groove is deeper from the inner side of the wiring member toward the outer side of the wiring member in the orthogonal direction.

  A fifth feature of the present invention relates to the second feature of the present invention, wherein the wiring member is composed of a low resistance body and a soft conductor covering the outer periphery of the low resistance body, and the groove is a soft conductive body. The gist is to be provided on the body.

  A sixth feature of the present invention relates to the first or second feature of the present invention, wherein the conductor is a wiring member that electrically connects a plurality of solar cells, and a deaeration path is provided in the wiring member. The gist of the present invention is that the through hole is a hole that penetrates the wiring material from the adhesive surface.

  A seventh feature of the present invention relates to the first feature of the present invention, wherein the conductor is a current collecting electrode provided in each of the plurality of solar cells, and the deaeration path is a current collecting on the bonding surface. It is a groove provided in the electrode, and the groove has a shape extending from one end of the collecting electrode to the other end of the collecting electrode along an orthogonal direction substantially orthogonal to the arrangement direction.

  An eighth feature of the present invention relates to the seventh feature of the present invention, and is summarized in that the collecting electrode has a curved surface that curves toward the inside of the groove in the boundary region between the bonding surface and the groove. .

  The ninth feature of the present invention is related to the seventh feature of the present invention, and the gist is that the depth of the groove increases from the inside of the collecting electrode toward the outside of the collecting electrode in the orthogonal direction. To do.

  ADVANTAGE OF THE INVENTION According to this invention, the solar cell module which can suppress that a bubble is enclosed between a resin adhesive and another member can be provided.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

1. 1st Embodiment (Schematic structure of a solar cell module)
A schematic configuration of the solar cell module 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a side view of a solar cell module 10 according to the present embodiment.

  The solar cell module 10 includes a plurality of solar cells 1, a light receiving surface side protective material 2, a back surface side protective material 3, a sealing material 4, and a wiring material 5. The solar cell module 10 seals the plurality of solar cells 1 between the light receiving surface side protective material 2 and the back surface side protective material 3.

  The plurality of solar cells 1 are arranged along the arrangement direction. The plurality of solar cells 1 are connected to each other by the wiring material 5.

  Solar cell 1 has a light receiving surface on which sunlight is incident and a back surface provided on the opposite side of the light receiving surface. The light receiving surface and the back surface are the main surfaces of the solar cell 1. The configuration of the solar cell 1 will be described later.

  The wiring member 5 is connected to the light receiving surface of one solar cell 1 and the back surface of another solar cell 1 adjacent to the one solar cell. Accordingly, the wiring member 5 is a conductor extending along the arrangement direction. Thereby, one solar cell 1 and the other solar cell 1 are electrically connected. The wiring member 5 includes a thin plate-like low resistance body (such as copper) and a soft conductor (such as eutectic solder) plated on the outer periphery of the low resistance body.

  The light receiving surface side protective material 2 is disposed on the light receiving surface side of the sealing material 4 and protects the surface of the solar cell module 10. As the light-receiving surface side protective material 2, glass having translucency and water shielding properties, translucent plastic, or the like can be used.

  The back surface side protective material 3 is disposed on the back surface side of the sealing material 4 and protects the back surface of the solar cell module 10. As the back surface side protective material 3, a resin film such as PET (Polyethylene Terephthalate), a laminated film having a structure in which an Al foil is sandwiched between resin films, and the like can be used.

  The sealing material 4 seals the plurality of solar cells 1 between the light receiving surface side protective material 2 and the back surface side protective material 3. As the sealing material 4, a translucent resin such as EVA, EEA, PVB, silicon, urethane, acrylic, or epoxy can be used.

  An Al frame (not shown) can be attached to the outer periphery of the solar cell module 10 having the above configuration.

(Configuration of solar cell)
Next, the configuration of the solar cell 1 will be described with reference to FIG. FIG. 2 is a plan view of the solar cell 1 on the light receiving surface side.

  As shown in FIG. 2, the solar cell 1 includes a photoelectric conversion unit 20, a thin wire electrode 30, and a bus bar electrode 40.

  The photoelectric conversion unit 20 generates photogenerated carriers by receiving sunlight. The photogenerated carrier refers to holes and electrons generated by absorption of sunlight into the photoelectric conversion unit 20. The photoelectric conversion unit 20 has an n-type region and a p-type region inside, and a semiconductor junction is formed at the interface between the n-type region and the p-type region. The photoelectric conversion unit 20 can be formed using a semiconductor substrate made of a crystalline semiconductor material such as single crystal Si or polycrystalline Si, or a semiconductor material such as a compound semiconductor material such as GaAs or InP. The photoelectric conversion unit 20 has a structure in which the characteristics of the heterojunction interface are improved by sandwiching a substantially intrinsic amorphous silicon layer between the single crystal silicon substrate and the amorphous silicon layer, that is, a so-called HIT. You may have a structure.

  In addition, the photoelectric conversion part 20 which concerns on this embodiment is shape | molded by about 100 mm each.

  The thin wire electrode 30 is an electrode that collects photogenerated carriers from the photoelectric conversion unit 20. As shown in FIG. 2, the thin wire electrode 30 is formed in a line shape along an orthogonal direction substantially orthogonal to the arrangement direction. A plurality of thin wire electrodes 30 are formed over substantially the entire light receiving surface of the photoelectric conversion unit 20. The fine wire electrode 30 can be formed using a resin-type conductive paste using a resin material as a binder and conductive particles such as silver particles as a filler. The thin wire electrode 30 is similarly formed on the back surface of the photoelectric conversion unit 20.

  The bus bar electrode 40 is an electrode that collects photogenerated carriers from the plurality of thin wire electrodes 30. As shown in FIG. 2, the bus bar electrodes 40 are formed along the arrangement direction so as to intersect the thin wire electrodes 30. The bus bar electrode 40 can be formed using a resin-type conductive paste using a resin material as a binder and conductive particles such as silver particles as a filler. Therefore, the bus bar electrode 40 is a conductor extending along the arrangement direction. The bus bar electrode 40 is similarly formed on the back surface of the photoelectric conversion unit 20.

  In addition, the solar cell 1 according to the present embodiment includes two bus bar electrodes 40 on the light receiving surface and the back surface. Therefore, the plurality of fine wire electrodes 30 and the bus bar electrodes 40 are formed in combination in a lattice shape.

  Here, as shown in FIG. 3, the wiring member 5 is electrically connected on the bus bar electrode 40. Accordingly, the bus bar electrode 40 and the wiring member 5 are both conductors extending along the arrangement direction.

(Detailed configuration of bus bar electrode and wiring material)
Next, a detailed configuration of the bus bar electrode 40 and the wiring member 5 will be described with reference to FIGS. FIG. 4 is an enlarged side view of the solar cell 1. FIG. 5 is an enlarged cross-sectional view taken along the line AA of FIG. 6 is an enlarged cross-sectional view taken along the line BB in FIG.

  As shown in FIG. 4, the bus bar electrode 40 and the wiring member 5 are connected via a resin layer 50. That is, the resin layer 50 is interposed between the bus bar electrode 40 and the wiring member 5.

  The resin layer 50 is formed on a flat plate with a resin adhesive. The resin adhesive is preferably cured at a temperature lower than the melting point of the eutectic solder, that is, about 200 ° C. or lower. As such a resin adhesive, for example, a two-component reaction in which a curing agent is mixed with an epoxy resin, an acrylic resin, or a urethane resin in addition to a thermosetting resin adhesive such as an acrylic resin or a highly flexible polyurethane type. A system adhesive or the like can be used. In this embodiment, a strip-shaped film sheet adhesive mainly composed of an epoxy resin is used as the resin adhesive. The resin adhesive includes a plurality of particles having conductivity. As the conductive particles, nickel, nickel with gold coating, or the like can be used.

  As shown in FIG. 4, the first structure 45 is formed by bonding the bus bar electrode 40 (conductor) to the resin layer 50. The bus bar electrode 40 has a plurality of first deaeration paths 41. The first degassing passage 41 is filled with a resin adhesive. That is, the bus bar electrode 40 has a plurality of first deaeration paths 41 filled with a resin adhesive. Therefore, the interface between the bus bar electrode 40 and the resin layer 50, that is, the first adhesive surface α is substantially horizontal.

  The first deaeration path 41 communicates with the outside of the structure 45 from the first adhesive surface α between the bus bar electrode 40 and the resin layer 50. In the present embodiment, the first deaeration path 41 is a groove provided on the first bonding surface α.

  Similarly, as shown in FIG. 4, the second structure 55 is formed by bonding the wiring member 5 (conductor) to the resin layer 50. The wiring member 5 has a plurality of second deaeration paths 51. The second deaeration path 51 is filled with a resin adhesive. That is, the wiring member 5 has a plurality of second deaeration paths 51 filled with a resin adhesive. Therefore, the interface between the wiring member 5 and the resin layer 50, that is, the second adhesive surface β is substantially horizontal.

  The second deaeration path 51 communicates with the outside of the second structure 55 from the second adhesive surface β between the wiring member 5 and the resin layer 50. In the present embodiment, the second deaeration path 51 is a groove provided on the second adhesive surface β.

  As shown in FIG. 5, the bus bar electrode 40 includes a first deaeration path 41 filled with a resin adhesive and a resin-type conductive paste 42 such as a silver paste. The first deaeration path 41 is a groove having a shape extending from one end of the bus bar electrode 40 to the other end of the bus bar electrode 40 along an orthogonal direction substantially orthogonal to the arrangement direction. That is, the first deaeration path 41 communicates with both side surfaces of the bus bar electrode 40 in the orthogonal direction. A plurality of such first deaeration channels 41 are formed at intervals of about 50 μm to 1 mm, for example.

  Further, as shown in FIG. 5, the depth of the first degassing passage 41 is deeper from the inside of the bus bar electrode 40 toward the outside of the bus bar electrode 40 in the orthogonal direction. That is, the depth of the first deaeration channel 41 is formed deeper toward the both side surfaces from the central part in the orthogonal direction on the cut surface orthogonal to the arrangement direction. The depth of the first deaeration path 41 is set in consideration of the thickness of the resin adhesive. Specifically, when the resin adhesive is pressure-bonded to the wiring member 5 and the bus bar electrode 40, the amount of the resin adhesive and the first desorption are set such that the resin adhesive is filled in the first degassing passage 41. It is preferable to set the depth of the air passage 41.

  As shown in FIG. 5, the wiring member 5 includes a second deaeration path 51 filled with a resin adhesive, a low resistance body 52, and a soft conductor 53. The soft conductor 53 covers the outer periphery of the low resistance body 52. As the low resistance body 52, a thin plate-like copper or the like can be used. As the soft conductor 53, eutectic solder or the like can be used. The second deaeration path 51 is preferably formed in the soft conductor 53 as shown in FIG.

  The second deaeration path 51 is a groove having a shape extending from one end of the wiring member 5 to the other end of the wiring member 5 along an orthogonal direction substantially orthogonal to the arrangement direction. That is, the second deaeration path 51 communicates with both side surfaces of the wiring member 5 in the orthogonal direction. A plurality of such second deaeration paths 51 are formed at intervals of about 50 μm to 1 mm, for example.

  Further, as shown in FIG. 5, the depth of the second deaeration path 51 is deeper from the inside of the wiring member 5 toward the outside of the wiring member 5 in the orthogonal direction. That is, the depth of the second deaeration path 51 is formed deeper in the cut surface perpendicular to the arrangement direction as it approaches the both side surfaces from the central portion in the orthogonal direction. The depth of the second deaeration path 51 is set in consideration of the thickness of the resin adhesive. Specifically, when the resin adhesive is pressure-bonded to the wiring member 5 and the bus bar electrode 40, the amount of the resin adhesive and the second desorption are set so that the resin adhesive is filled in the second degassing passage 51. It is preferable to set the depth of the air passage 51.

  As shown in the figure, the first adhesive surface α between the bus bar electrode 40 and the resin layer 50 and the second adhesive surface β between the wiring member 5 and the resin layer 50 are virtual horizontal surfaces. That is, the resin adhesive filled in the resin layer 50, the first deaeration path 41, and the second deaeration path 51 is integrally formed.

  As shown in FIG. 6, the bus bar electrode 40 has a curved surface that curves toward the inside of the first deaeration channel 41 in the boundary region γ1 between the first adhesion surface α and the first deaeration channel 41. That is, the first adhesive surface α and the first deaeration path 41 are smoothly connected without being bent.

  Similarly, the wiring member 5 has a curved surface that curves toward the inside of the second deaeration path 51 in the boundary region γ <b> 2 between the second adhesion surface β and the second deaeration path 51. That is, the second adhesive surface β and the second deaeration path 51 are smoothly connected.

(Method for manufacturing solar cell module)
Next, a method for manufacturing the solar cell module 10 according to this embodiment will be described.
First, using a printing method such as a screen printing method or an offset printing method on a 100 mm square solar cell substrate, an epoxy thermosetting silver paste is applied on the light receiving surface and the back surface of the photoelectric conversion unit 20 in a predetermined manner. Arrange in a pattern. As shown in FIG. 2, the predetermined pattern refers to a lattice shape formed by two bus bar electrodes 40 extending along the arrangement direction and a plurality of thin wire electrodes 30 extending along the orthogonal direction. The thin wire electrode can be formed with a width of about 100 μm and a height of about 30 μm. The bus bar electrode 40 can be formed with a width of about 1.2 mm and a height of about 50 μm. On the surface of the bus bar electrode 40, a plurality of first deaeration channels 41 having a depth of 10 to 40 μm and a width of 10 to 100 μm formed at intervals of 50 μm to 1 mm are used.

  The silver paste is heated under predetermined conditions to volatilize the solvent, and then further heated to perform the main drying. Thus, the solar cell 1 is produced.

  Next, the wiring member 5 is thermocompression bonded onto the bus bar electrode 40 via a resin adhesive containing a plurality of conductive particles. Specifically, first, the resin adhesive formed in a film shape and the wiring member 5 are sequentially arranged on the bus bar electrodes 40 formed on the light receiving surface and the back surface of the photoelectric conversion unit 20. Next, the wiring member 5 is pressed toward the solar cell 1 at a pressure of 2 to 3 MPa for about 15 to 30 seconds with a heater block heated to about 150 to 200 ° C. As the wiring member 5, a material in which the periphery of 200 μm-thick copper (low resistance body 52) is covered with 40 μm-thick solder (soft conductor 53) can be used. As the resin adhesive, a film-like resin formed with a width of 1 mm and a thickness of 30 μm can be used. In addition, on the surface of the wiring member 5, a plurality of second deaeration paths 51 having a depth of 10 to 40 μm and a width of 10 to 100 μm formed at intervals of 50 μm to 1 mm are used.

  Next, an EVA sheet (sealing material 4), a plurality of solar cells 1, an EVA sheet (sealing material 4), and a PET sheet (back surface side protection material 3) are placed on the glass substrate (light-receiving surface side protection material 2). A laminated body is formed by sequentially laminating.

  Next, the laminated body is temporarily pressure-bonded by thermocompression bonding in a vacuum atmosphere, and then EVA is completely cured by heating under a predetermined condition. Thus, the solar cell module 10 is manufactured.

  Note that a terminal box, an Al frame, or the like can be attached to the solar cell module 10.

(Function and effect)
According to the solar cell module 10 according to the present embodiment, the bus bar electrode 40 has a shape that extends from one end to the other end of the bus bar electrode 40 along the orthogonal direction substantially orthogonal to the arrangement direction on the adhesive surface with the resin layer 50. The first deaeration passage 41 having In addition, the wiring member 5 has a second deaeration path 51 having a shape extending from one end to the other end of the wiring member 5 along an orthogonal direction substantially orthogonal to the arrangement direction on the adhesive surface with the resin layer 50.

  Thus, the solar cell module 10 includes a structure (the first structure 45 or the second structure 55) configured by bonding the conductor (the bus bar electrode 40 or the wiring member 5) to the resin layer 50. Have. The conductor has a plurality of grooves (the first deaeration path 41 or the second deaeration path 51) communicating from the adhesive surface with the resin layer 50 to the outside of the structure.

  As described above, a plurality of grooves are formed in the conductor bonded to the resin layer 50. Accordingly, when the resin adhesive is thermocompression-bonded to the conductor, it is possible to promote deaeration of air sandwiched between the conductor and the resin adhesive or air dissolved in the resin adhesive. Specifically, the resin adhesive melted by heating is filled in the groove, whereby air is pushed out of the structure. Therefore, bubbles can be prevented from remaining at the interface between the conductor and the resin layer 50. As a result, an increase in contact resistance due to bubbles remaining at the interface between the conductor and the resin layer 50 can be reduced.

  Further, since the plurality of grooves are filled with the resin adhesive, the adhesive force between the conductor and the resin layer can be improved by a so-called anchor effect.

  In addition, the conductor has a curved surface that curves toward the inside of the groove in a boundary region (boundary region γ1 or boundary region γ2) between the bonding surface (first bonding surface α or second bonding surface β) and the groove. Therefore, when the conductor is thermocompression bonded to the resin adhesive, the resin adhesive can be smoothly guided into the groove.

  Further, the depth of the groove becomes deeper from the inside to the outside of the conductor in the orthogonal direction. Therefore, air can be efficiently discharged from the inside toward the outside.

  Further, the groove (second deaeration path 51) is formed in the soft conductor 53 constituting the wiring member 50. Therefore, it is not necessary to process the low resistance body as the core material. Therefore, the groove can be easily formed.

2. Second Embodiment Next, a second embodiment of the present invention will be described with reference to the drawings. The difference between this embodiment and the said 1st Embodiment is a point by which the several through-hole is provided in the wiring material 6 with which the solar cell module which concerns on this embodiment is provided. Therefore, in the following description, description of the same or similar parts as those in the first embodiment is omitted.

  FIG. 7 is a plan view of the solar cell 1 on the light receiving surface side. The wiring member 6 is provided with a plurality of through holes 61. 8 is a cross-sectional view taken along the line CC of FIG. The first deaeration path 41 is not formed in the bus bar electrode 40 according to the present embodiment. The wiring member 6 (conductor) is bonded to the resin layer 50 to form the third structure 65. The wiring member 6 has a plurality of through holes 61. The through hole 61 is filled with a resin adhesive. That is, the wiring member 6 has a plurality of through holes 61 filled with a resin adhesive. Therefore, the interface between the wiring member 6 and the resin layer 50, that is, the third adhesive surface δ is substantially horizontal.

  In the present embodiment, as shown in FIG. 8, the resin adhesive may not completely fill the through hole 61. In the present embodiment, the state where the resin adhesive is “filled” includes a state where the resin adhesive protrudes from the upper part of the through hole 61 and a state where the resin adhesive does not reach the upper part of the through hole 61.

  The through hole 61 is a hole that penetrates the wiring member 6 from the third adhesive surface δ between the wiring member 6 and the resin layer 50. As such a through hole 61, for example, a plurality of holes having a size of about 200 μm square can be formed at intervals of about 1 mm.

(Function and effect)
According to the solar cell module according to the present embodiment, the wiring member 6 has a hole penetrating the wiring member 6 from the adhesive surface with the resin layer 50.

  Thus, the solar cell module has a structure (third structure 65) configured by bonding a conductor (wiring member 6) to the resin layer 50, and the conductor is the resin layer 50. And a plurality of deaeration paths (through holes 61) communicating from the bonding surface to the outside of the structure.

  Thus, a plurality of through holes 61 are formed in the conductor bonded to the resin layer 50. Accordingly, when the resin adhesive is thermocompression-bonded to the conductor, it is possible to promote deaeration of air sandwiched between the conductor and the resin adhesive or air dissolved in the resin adhesive. Specifically, the resin adhesive melted by heating is filled in the through holes, so that air is pushed out of the structure. Therefore, bubbles can be prevented from remaining at the interface between the conductor and the resin layer 50. As a result, an increase in contact resistance due to bubbles remaining at the interface between the conductor and the resin layer 50 can be reduced.

  Further, since the plurality of grooves are filled with the resin adhesive, the adhesive force between the conductor and the resin layer can be improved by a so-called anchor effect.

(Other embodiments)
Although the present invention has been described according to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the first embodiment, the effect of the present invention can be obtained by forming a deaeration path in either the bus bar electrode 40 or the wiring member 5.

  In the first and second embodiments, the solar cell 1 may not include the bus bar electrode 40. The wiring material is mechanically and electrically connected to the fine wire electrode via a resin adhesive.

  Moreover, in the said 1st and 2nd embodiment, there is no restriction | limiting in the space | interval in which the deaeration path (a groove | channel or a through-hole) which a wiring material or a bus-bar electrode has is formed. Moreover, there is no special restriction | limiting also in the shape of a groove | channel and the shape of the hole of a through-hole.

  Moreover, in the said 1st and 2nd embodiment, the deaeration path (a groove | channel or a through-hole) which a wiring material or a bus-bar electrode has does not need to be orthogonal to the sequence direction.

  Moreover, in the said 1st and 2nd embodiment, although the thin wire electrode was formed in the line form, it is not restricted to this. Moreover, the thin wire electrode formed on the back surface side of the solar cell may be formed so as to cover the entire back surface. The present invention does not limit the shape of the thin wire electrode formed on the back surface side.

  In the first and second embodiments, the resin adhesive, the wiring material, and the bus bar electrode may have different widths.

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

    Hereinafter, the solar cell according to the present invention will be specifically described with reference to examples, but the present invention is not limited to those shown in the following examples, and within the scope not changing the gist thereof, It can be implemented with appropriate changes.

Example 1
First, an epoxy thermosetting silver paste was formed in a lattice shape on a 100 mm square solar cell substrate using a screen printing method. The thin wire electrode had a width of 100 μm and a height of 30 μm. The bus bar electrode had a width of 1.2 mm and a height of 50 μm.

  Next, a plurality of grooves extending in the short direction of the wiring material were formed on the surface of the wiring material using a mold. The wiring material had a width of 1.5 mm, a core wire thickness of 200 μm, and a solder thickness of 40 μm. The grooves had a depth of 30 μm, a width of 100 μm, and an interval of 1 mm.

  Next, a sheet-like resin adhesive and a wiring material were placed on the bus bar electrode. The resin adhesive had a width of 1 mm and a thickness of 30 μm. Then, using a heater block heated to 200 ° C., the resin adhesive was cured by pressing the wiring member against the solar cell substrate at a pressure of 2 MPa for 15 seconds. A solar cell according to Example 1 was produced as described above.

(Example 2)
In this embodiment, a groove extending in the short direction of the bus bar electrode is formed also in the bus bar electrode. The grooves had a depth of 30 μm, a width of 100 μm, and an interval of 1 mm. Other configurations and creation methods are the same as those in the first embodiment.

(Comparative example)
In this comparative example, no groove was formed in either the wiring material or the bus bar electrode. Other configurations and creation methods are the same as those in the first embodiment.

(Temperature cycle test)
About the solar cell which concerns on Example 1, Example 2, and the comparative example mentioned above, the temperature cycle test was done using the thermostat, and the output of the solar cell before and behind a test was compared.

  The temperature cycle test was performed in accordance with the provisions of JIS C 8917. Specifically, each sample is held in a thermostatic bath, raised from 25 ° C. to 90 ° C. over 45 minutes, held at this temperature for 90 minutes, and then lowered to −40 ° C. over 90 minutes. Hold for 90 minutes and then increase to 25 ° C. over 45 minutes. This was performed as 200 cycles for one cycle (6 hours).

  As shown in the table, it was confirmed that the output ratio of the solar cells according to Examples 1 and 2 generated higher output than the comparative example before and after the test.

  This result was obtained because grooves were formed in the wiring material or bus bar electrode in the solar cells according to Examples 1 and 2. That is, since air is discharged through such a groove, the air remaining at the interface between the wiring member and the resin adhesive or the interface between the bus bar electrode and the resin adhesive can be reduced.

  From the above results, in the structure formed by bonding the conductor to the resin layer, bubbles remain by forming a deaeration path communicating from the bonding surface between the conductor and the resin layer to the outside of the structure. It was found that can be suppressed.

1 is a side view of a solar cell module 10 according to a first embodiment of the present invention. It is a top view by the side of the light-receiving surface of the solar cell 1 which concerns on 1st Embodiment of this invention. It is a top view by the side of the light-receiving surface of the solar cell 1 which concerns on 1st Embodiment of this invention. 1 is an enlarged side view of a solar cell module 10 according to a first embodiment of the present invention. It is sectional drawing in the AA cut surface of FIG. It is sectional drawing in the BB cut surface of FIG. It is a top view by the side of the light-receiving surface of the solar cell 1 which concerns on 2nd Embodiment of this invention. It is sectional drawing in the CC cut surface of FIG.

Explanation of symbols

α ... Adhesive surface β ... Adhesive surface δ ... Adhesive surface γ1 ... Boundary region γ2 ... Boundary region 1 ... Solar cell 2 ... Light-receiving surface side protective material 3 ... Back side protective material 4 ... Sealing material 5 ... Wiring material 6 ... Wiring material DESCRIPTION OF SYMBOLS 10 ... Solar cell module 20 ... Photoelectric conversion part 30 ... Fine wire electrode 40 ... Bus-bar electrode 41 ... 1st deaeration path 42 ... Conductive paste 45 ... Structure 45 ... 1st structure 50 ... Resin layer 50 ... Wiring material 51 ... 2nd deaeration way 52 ... Low resistance 53 ... Soft conductor 55 ... 2nd structure 61 ... Through-hole 65 ... 3rd structure

Claims (9)

A plurality of solar cells are sealed between the light receiving surface side protection member and the back surface side protection member, and the plurality of solar cells is a solar cell module arranged along the arrangement direction,
The conductor extending along the arrangement direction has a structure bonded to a resin layer constituted by a resin adhesive,
The conductor has a plurality of deaeration paths communicating from the adhesive surface between the conductor and the resin layer to the outside of the structure.
The solar cell module, wherein the resin adhesive is filled in the deaeration path. The conductor is a wiring material that electrically connects the plurality of solar cells,
The deaeration path is a groove provided in the wiring member on the bonding surface,
2. The solar cell module according to claim 1, wherein the groove has a shape extending from one end of the wiring member to the other end of the wiring member along an orthogonal direction substantially orthogonal to the arrangement direction. The solar cell module according to claim 2, wherein the wiring member has a curved surface that curves toward the inside of the groove in a boundary region between the bonding surface and the groove. 3. The solar cell module according to claim 2, wherein a depth of the groove is deeper from an inner side of the wiring member toward an outer side of the wiring member in the orthogonal direction. The wiring material is composed of a low resistance body and a soft conductor covering an outer periphery of the low resistance body,
The solar cell module according to claim 2, wherein the groove is provided in the soft conductor. The conductor is a wiring material that electrically connects the plurality of solar cells,
The deaeration path is a through hole provided in the wiring member,
The solar cell module according to claim 1, wherein the through hole is a hole that penetrates the wiring member from the adhesion surface. The conductor is a collecting electrode provided in each of the plurality of solar cells,
The deaeration path is a groove provided in the current collecting electrode on the bonding surface,
2. The solar cell module according to claim 1, wherein the groove has a shape extending from one end of the current collecting electrode to the other end of the current collecting electrode along an orthogonal direction substantially orthogonal to the arrangement direction. . The solar cell module according to claim 7, wherein the current collecting electrode has a curved surface that curves toward the inside of the groove in a boundary region between the bonding surface and the groove. The solar cell module according to claim 7, wherein the depth of the groove is deeper from the inside of the current collecting electrode toward the outside of the current collecting electrode in the orthogonal direction.