JP5183257B2 - Solar cell module - Google Patents

Description

  The present invention relates to a solar cell module having a plurality of solar cells electrically connected to each other by a wiring material.

The solar cell module has a plurality of solar cells that are electrically connected to each other by a wiring material. Conventionally, the wiring material is bonded to the electrode of the solar cell with solder. In addition, it has been studied to bond a wiring material to an electrode of a solar cell using an anisotropic conductive adhesive containing conductive particles in a polymer resin instead of solder (for example, see Patent Document 1). According to this method, the wiring material can be bonded at a lower temperature than in the case of using solder, so that the working efficiency in manufacturing can be increased and the manufacturing cost can be reduced.
JP 2005-101519 A

  In Patent Document 1, a wiring material made of solder-plated copper is bonded to an electrode of a solar cell using a film adhesive. However, in this method, stress is applied to the interface between the wiring material and the film-like adhesive or the interface between the film-like adhesive and the solar cell due to the difference in the linear expansion coefficient between the wiring material, the film-like adhesive and the solar cell. When added, the adhesive strength may be reduced, and the reliability may be reduced.

  Then, this invention is made | formed in view of said problem, and it aims at providing the solar cell module which improved reliability.

  A solar cell module according to one aspect of the present invention has a connection electrode on a surface thereof, a plurality of solar cells arranged along the arrangement direction, and electrically connected on the connection electrode, the arrangement direction being a longitudinal direction A wiring material, and an adhesive that bonds the wiring material and the connection electrode, and the wiring material includes a plurality of connection portions provided so as to be separated from each other in a short direction perpendicular to the longitudinal direction, And a conductive layer provided so as to cover the surface of the connection portion facing the surface of the connection electrode.

  In one aspect of the present invention, the wiring member may have a connecting portion that connects a plurality of connecting portions.

  In one aspect of the present invention, the adhesive may be filled in a gap that separates adjacent connecting portions.

  In one aspect of the present invention, the adhesive material may include a resin and conductive particles, and the wiring material may be electrically connected to the connection electrode through the conductive particles.

  In one aspect of the present invention, the connection electrode may have a protrusion on the surface facing the conductive layer, and the wiring member may be electrically connected to the connection electrode by the protrusion being recessed in the conductive layer. .

  In one aspect of the present invention, the adhesive may be insulative.

  According to the present invention, a solar cell module with improved reliability 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.
<< First Embodiment >>
First, the solar cell module 1 which concerns on 1st Embodiment of this invention is demonstrated using FIGS. 1-4.

(Configuration of solar cell module)
FIG. 1 is a conceptual cross-sectional view showing the configuration of the solar cell module 1 according to the present embodiment. The solar cell module 1 includes a plurality of solar cells 31, 32, 33, 34... Electrically connected by the wiring material 2, a light receiving surface protection member 107, a sealing material 109, and a back surface protection member 108. .

  A light-transmitting surface protective member 107 is bonded to a light-receiving surface side of the plurality of solar cells 31, 32, 33, 34. The surface protection member 107 is configured using a light-transmitting material such as glass or light-transmitting plastic. Further, a back surface protection member 108 is bonded to the back surface side of the solar cell 3 with a sealing material 109. The back surface protection member 108 is made of, for example, a resin film such as PET or a laminated film having a structure in which an Al foil is sandwiched between resin films.

  The sealing material 109 is a light-transmitting resin such as EVA or PVB, and has a function of sealing the solar cell 3. Further, a terminal box for taking out electric power (not shown) is arranged on the back surface of the back surface protection member 108, for example. Further, a frame body is attached to the outer peripheral portion of the solar cell module 1 as necessary.

  In manufacturing such a solar cell module 1, first, the light-receiving surface protection member 107, the sealing material 109, the plurality of solar cells 31, 32, 33, 34. Laminate to create a laminate. Next, it heats, applying a pressure from the upper and lower sides of a laminated body, and the solar cell module 1 is created.

(Structure of wiring material)
As shown in FIG. 1, the wiring member 2 includes a light receiving surface electrode (not shown) of one solar cell 31 and a solar cell 32 of the other solar cell 31 among the plurality of solar cells 31, 32. A back electrode (not shown) is electrically connected. In the wiring member 2, the arrangement direction of the solar cells 31, 32... Is the longitudinal direction X, and the direction orthogonal to the arrangement direction is the short direction Y.

  FIG. 2 is a cross-sectional view when the wiring member 2 is cut along the short direction Y. FIG. As shown in the figure, a plurality of connecting portions 21, 21,. In the present embodiment, as shown in FIG. 1, the lower surface side of one wiring member is connected to the connection electrode 4 </ b> B (not shown) on the light receiving surface side of one adjacent solar cell 31. The upper surface side of the wiring member is connected to a connection electrode 41B (not shown) on the back surface side of the other adjacent solar cell 32. In the present embodiment, as shown in FIG. 2, the connection portions 21 are provided on the upper surface side and the lower surface side of the wiring material 2, but the connection portions 21 are provided only on the side facing the connection electrodes 4 </ b> B and 41 </ b> B of the wiring material 2. May be provided.

  In addition, a conductive layer 23 is formed on the upper surface of the connection portion 21 formed on the upper surface side of the wiring material 2 shown in FIG. 2 and the lower surface of the connection portion 21 formed on the lower surface side of the wiring material 2. ing. At this time, the plurality of connecting portions 21 are arranged at predetermined intervals so that the adjacent conductive layers 23 are separated from each other by the grooves 22. The connection part 21 consists of electroconductive materials, such as copper foil. Further, the conductive layer 23 is formed on the surface of the connection portion 21 by a conductive material such as tin or solder by plating or dipping.

  In the present embodiment, the wiring member 2 has a connecting portion 24 for connecting a plurality of connecting portions 21, 21. Therefore, the wiring member 2 in the present embodiment includes a plurality of connection portions 21 separated from each other by grooves 22 formed along the longitudinal direction X on the surface of the solar cells 31, 32. The shape which has 21 ... is comprised. By providing the connecting portion 24, the wiring member 2 can be easily handled.

(Solar cell structure)
FIG. 3 is a plan view of the solar cell 31 according to the present embodiment as viewed from the light receiving surface side, and FIG. 3B is a plan view as viewed from the back surface side. As shown in FIGS. 3A and 3B, the solar cell 31 includes a photoelectric conversion unit 5 and current collecting electrodes 4 and 41 arranged on the light receiving surface and the back surface of the photoelectric conversion unit 5, respectively. have. The photoelectric conversion unit 5 internally generates a photogenerated carrier by receiving light. The photogenerated carriers are electrons and holes generated in the photoelectric conversion unit 5 by receiving light.

  The photoelectric conversion unit 5 is made of a semiconductor material having a semiconductor junction such as a pn junction or a pin junction. Semiconductor materials include crystalline silicon semiconductors such as single crystal semiconductor silicon and polycrystalline silicon, compound semiconductors such as GaAs, amorphous silicon thin film semiconductors, compound thin film semiconductors, and other semiconductor materials made of known semiconductor materials. Can be used. As a material for forming a semiconductor junction with the semiconductor material, a crystalline semiconductor, an amorphous semiconductor, a compound semiconductor, or other known semiconductor materials can be used.

  As shown in the plan view of FIG. 3A, the current collecting electrode 4 formed on the light receiving surface of the photoelectric conversion unit 5 includes a plurality of fine wire electrodes 4A, 4A,... And connection electrodes 4B, 4B. have. The connection electrodes 4B and 4B are electrodes to which the wiring material 2 is connected.

  The thin wire electrodes 4A, 4A... Are electrodes for collecting electron / hole carriers generated in the photoelectric conversion unit 5 by light incidence. The thin wire electrodes 4A, 4A,... Are arranged in parallel to each other so as to cover substantially the entire light receiving surface of the photoelectric conversion unit 5.

  The connection electrodes 4B and 4B are electrodes to which the wiring material 2 is connected. Therefore, the connection electrodes 4B and 4B are formed with the arrangement direction of the solar cells 31, 32. Further, the connection electrodes 4B and 4B are formed with the direction perpendicular to the longitudinal direction X of the plurality of thin wire electrodes 4A, 4A. Therefore, the connection electrodes 4B and 4B intersect with the plurality of thin wire electrodes 4A, 4A. The connection electrodes 4B and 4B also have a function of collecting carriers collected by the plurality of thin wire electrodes 4A, 4A. Note that the dimensions and number of the thin wire electrodes 4A and the dimensions and number of the connection electrodes 4B are appropriately set in consideration of the dimensions and physical properties of the photoelectric conversion unit 5.

  FIG.3 (b) is the top view which looked at the solar cell 31 from the back surface side. The collecting electrode 41 formed on the back surface also has a plurality of fine wire electrodes 41A, 41A,... And connecting electrodes 41B, 41B, like the collecting electrode 11 formed on the light receiving surface side. The dimensions and number of the fine wire electrodes 41A on the back surface side and the dimensions and number of the connection electrodes 41B are appropriately set in consideration of the dimensions and physical properties of the photoelectric conversion unit 5. In addition, the current collecting electrode 41 on the back surface side can take various configurations without being limited thereto. For example, a conductive material may be formed on the entire back surface to form a current collecting electrode.

  The collector electrodes 4 and 41 are formed from, for example, a thermosetting conductive paste using an epoxy resin as a binder and conductive particles as a filler. In the case of a single crystal silicon solar cell, a polycrystalline silicon solar cell, etc., not limited to this, a fired paste composed of a metal powder such as silver or aluminum, a glass frit and an organic vehicle is used. Also good. Alternatively, a general metal material such as silver or aluminum may be used.

(Connection of wiring material)
FIG. 4 is a plan view for explaining the connection relationship between the wiring member 2 and the connection electrode 4B. FIG. 5 is a cross-sectional view taken along the line AA shown in FIG.

  As shown in FIG. 4, the wiring member 2 is bonded so that the longitudinal direction X of the wiring member 2 is aligned with the solar cells 31, 32. Further, as shown in FIG. 5, the wiring member 2 is bonded to the surface of the connection electrode 4 </ b> B with an adhesive 7. In the present embodiment, a case where the adhesive 7 is composed of a resin 7b containing a plurality of conductive particles 7a will be described. In the wiring member 2, the conductive layer 23 provided on the side facing the connection electrode 4B of the plurality of connection portions 21, 21... Indirectly contacts the connection electrode 4B via the conductive particles 7a, 7a. Thus, it is electrically connected to the connection electrode 4B. Further, the wiring member 2 and the connection electrode 4B are mechanically connected by the resin 7b. Further, the resin 7b also enters the gap formed by the groove 22 between the adjacent connecting portions 21 and 21. Note that the wiring member 2 and the connection electrode 41B are similarly connected on the back surface side.

  Examples of the material of the resin 7b include an epoxy resin, an acrylic resin, a polyimide resin, a phenol resin, a urethane resin, a silicon resin, and the like. At least one selected from these materials, or a mixture or copolymer of these resins is used. Can be applied.

  As the conductive particles 7a, for example, at least one metal particle selected from nickel, copper, silver, aluminum, tin, gold or the like having a diameter of about 0.5 μm to about 20 μm, or an alloy or a mixture thereof can be applied. Further, it may be one in which at least one inorganic oxide selected from alumina, silica, titanium oxide, glass and the like is subjected to metal coding, epoxy resin, acrylic resin, polyimide resin, phenol resin, urethane resin, silicon At least one selected from resins and the like, or a copolymer or mixture of these resins may be provided with a metal coating.

  The concentration of the conductive particles 7a contained in the resin 7b is, for example, a concentration such that the wiring member 2 and the connection electrode 4B are electrically connected by 1 to 3 conductive particles 7a stacked in the thickness direction. Is done. By setting it as such a density | concentration, the number of the contact interfaces of the electroconductive particle 7a which exists in the thickness direction can be reduced. Therefore, the contact resistance generated at the contact interface between the conductive particles 7a can be reduced, so that the resistance loss between the wiring member 2 and the connection electrode 4B can be reduced.

(Function and effect)
The effects of the present invention will be described below in comparison with the structure of the comparative example shown in FIG.

  In the structure of the comparative example, the copper flat plate 21 whose surface is covered with the solder layer 23 is used as the wiring member 2 as described above. The solder layer 23 is usually formed by a dipping method in which the flat plate 21 is immersed in a solder bath. However, the surface shape of the solder layer 23 formed by the dip method becomes convex as shown in FIG. 6 due to the influence of the surface tension of the molten solder at the time of formation. For example, when a solder having a thickness of 40 μm is to be formed on the surface of a copper flat plate having a width in the short direction Y of about 1.5 mm, the thickness of the actually formed solder is about 40 μm near the thickest central portion. It becomes about 1 μm or less at the thin end. Therefore, at the end portion in the short direction Y, the distance between the surface of the connection electrode 4B and the surface of the wiring member 2 is larger than the dimension of the conductive particles 7a. For this reason, in the structure of the comparative example, it is difficult to electrically connect the wiring member 2 and the connection electrode 4B via the conductive particles 7a at the end in the short direction Y. An increase was incurred.

  On the other hand, the wiring member 2 of the present embodiment includes a plurality of connecting portions 21, 21..., And a plurality of connecting portions 21, 21. The conductive layer 23 is formed so as to cover the surface on the side facing the connection electrode. For this reason, in this embodiment, although the shape of each conductive layer 23 is convex, since the width of the connecting portion 21 is narrow, the thickest portion (center portion) and the thinnest portion (ends) The difference in thickness with respect to the part) can be made significantly smaller than the structure of the comparative example. For this reason, according to the present embodiment, as shown in FIG. 5, it is possible to electrically connect the wiring member 2 and the connection electrode 4b via the conductive particles 7a over substantially the entire surface of each connection portion 21. The increase in resistance of the connection resistance can be suppressed.

  Further, in the structure of the comparative example, the connection electrode 4B and the wiring member 2 are connected at one place near the central portion where the thickness of the solder formed on the surface of the flat plate 21 is the thickest. For example, connection is possible at a plurality of locations of each connection portion 21. Therefore, the reliability of connection between the connection electrode 4B and the wiring member 2 can be increased as compared with the structure of the comparative example.

  Moreover, since a solar cell module is normally used outdoors, it is affected by ambient temperature changes. In general, the thermal expansion coefficient of the resin material used as the resin 7 b for the conductive adhesive 7 is larger than the thermal expansion coefficient of copper used for the connection portion 21 of the wiring member 2. For this reason, the wiring member 2 is affected by the thermal expansion / contraction of the resin 7b accompanying the ambient temperature change. For this reason, in the structure of the comparative example, the amount of the resin 7b existing between the wiring member 2 and the connection electrode 4B at the end portion in the short direction Y is larger than the amount of the resin 7b existing in the center portion. There is a possibility that a greater stress is applied to the wiring member 2 at the end portion than at the center portion, and the bonding strength of the wiring member 2 is lowered. For this reason, there existed a possibility that the output characteristic of a solar cell module may fall after use for a long time.

  On the other hand, in this embodiment, the amount of the resin 7b at the end portion and the amount of the resin at the central portion are substantially equal. In addition, in this embodiment, the resin 7b enters the gap formed by the groove 22 existing between the connecting portions 21 and 21. For this reason, the connection strength between the wiring member 2 and the connection electrode 4B can be increased as compared with the structure of the comparative example. Therefore, according to this embodiment, since the output fall after long-time use can be suppressed, the solar cell module with improved reliability can be provided.

  Further, in the present embodiment, the pressure applied when the wiring member 2 and the connection electrodes 4B, 41B are bonded is dispersed and applied to the solar cells 31, 32,. it can. Therefore, generation | occurrence | production of defects, such as a crack, a chip | tip, or a crack, is suppressed in a solar cell, and a yield improves.

  Moreover, in this embodiment, the wiring material 2 has the connection part 24 for connecting the some connection parts 21, 21, .... Accordingly, the wiring material 2 can be easily handled and has excellent workability.

  In the above-described embodiment, the connection portion 24 is provided between the connection portions 21, 21... On the upper surface side of the wiring member 2 and the connection portions 21, 21. The shape of the material 2 is not limited to this. FIG. 7 is a plan view illustrating an example of the wiring member according to the present embodiment, as viewed from the connection electrode 4B side. As shown in the figure, the connecting portion 24 may be provided in a shape that divides the groove 22 in plan view. In this case, the groove 22 is not limited to the groove shape, and may be a slit shape. Even when the wiring member 2 having such a shape is used, the same effects as those of the above-described embodiment are obtained.

In the above-described embodiment, the conductive layer 23 is not provided on the side surface of the connection portion 21, but the position where the conductive layer 23 is provided is not limited thereto. For example, as shown in the cross-sectional view of FIG. 8, the surface of the connecting portions 21, 21... Including the surface of the connecting portion 24 may be entirely covered with the conductive layer 23. Even if it is such a form, there exists an effect similar to embodiment mentioned above.
<< Second Embodiment >>
A second embodiment of the present invention will be described with reference to FIG. In the following description, descriptions of the same or similar parts as in the first embodiment are omitted.

(Connection of wiring material)
FIG. 9 is an enlarged cross-sectional view of a main part for explaining the connection relationship between the wiring member 2 and the connection electrode 4B.

  In the present embodiment, as shown in FIG. 9, the connection electrode 4B has a protrusion 45, and the protrusion 45 is recessed into the conductive layer 23, whereby the wiring member 2 and the connection electrode 4B are electrically connected. ing. Further, the wiring member 2 and the connection electrode 4B are mechanically connected by the adhesive layer 7. The protrusions 45 as shown in FIG. 9 can be created, for example, by forming the connection electrodes 4B by screen printing. That is, the projection 45 reflecting the pattern of the mesh plate can be created on the connection electrode 4B due to the influence of the mesh plate used for screen printing. In the case of the protrusion 45 reflecting the pattern of the mesh plate, the height of the protrusion 45 is about 1 μm to about 20 μm, and the pitch is about 10 μm to about 30 μm. And the protrusion 45 can be sunk in the conductive layer 23 by adjusting suitably the magnitude | size of the pressure applied when connecting the wiring material 2 and the connection electrode 4b.

(Function and effect)
In the present embodiment, as in the first embodiment, the wiring member 2 and the connection electrode 4B can be electrically connected to each other through the protrusions 45 over substantially the entire surface of each connection portion 21, and the resistance of the connection resistance Increase can be suppressed. Further, the electrical connection between the wiring member 2 and the connection electrode 4B can also be made at the end of the wiring member.

  Moreover, since the output fall after use for a long time can be suppressed, the solar cell module with improved reliability can be provided.

  Furthermore, the generation of defects such as cracks, chips or cracks in the solar cell can be suppressed, and the yield can be improved.

In the present embodiment, as described above, the protrusion 45 is recessed into the conductive layer 23 to directly connect the wiring member 2 and the connection electrode 4B. Therefore, the adhesive layer can be an insulating layer as well as a conductive layer including conductive particles in the resin used in the first embodiment. Further, the wiring member 2 and the connection electrode 4B may be electrically connected by both the protrusion 45 and the conductive particles.
(Example)
Hereinafter, the solar cell module according to the present invention will be specifically described with reference to examples.

  As examples of the present invention, solar cell modules according to the first and second embodiments were produced as follows. In the following manufacturing method, a process is divided into steps 1 to 5 and described.

<Step 1> Formation of Photoelectric Conversion Part First, an n-type single crystal silicon substrate of about 125 mm square having a resistivity of about 1 Ω · cm and a thickness of about 200 μm was prepared. Next, an CVD method is used to form an i-type amorphous silicon layer having a thickness of about 5 nm and a p-type amorphous silicon layer having a thickness of about 5 nm on the light-receiving surface of the n-type single crystal silicon substrate. Were formed in this order.

  Next, an i-type amorphous silicon layer having a thickness of about 5 nm and an n-type amorphous silicon layer having a thickness of about 5 nm are formed on the back surface of the n-type single crystal silicon substrate by CVD. Formed in order.

  Next, an ITO film having a thickness of about 100 nm was formed on each of the p-type amorphous silicon layer and the n-type amorphous silicon layer by sputtering.

  The photoelectric conversion part of the solar cell which concerns on an Example was produced according to the above process.

<Process 2> Current collection electrode formation Next, on the surface of the ITO film | membrane distribute | arranged to the light-receiving surface side and back surface side of a photoelectric conversion part, respectively by the printing method, using an epoxy-type thermosetting silver paste, the following A current collecting electrode having a shape was formed.

  A plurality of thin wire electrodes 4A and 41A having a width of about 100 μm and a thickness of about 40 μm were formed at a pitch of about 2 mm for the samples of Example 1 and Example 2 relating to the first embodiment and the second embodiment, respectively. In addition, as the samples of Example 1 and Example 2, the connection electrodes 4B and 41B having a length of about 122 mm, a width of about 1.0 mm, and a thickness of about 50 μm are arranged in a direction orthogonal to the thin wire electrodes 4A and 41A, respectively. Two were formed.

<Step 3> Wiring material preparation For Example 1 and Example 2, a copper thin plate having a width of about 1.5 mm, a thickness of about 0.15 mm, and a length of about 255 mm is prepared, and the width along the longitudinal direction X is provided on both sides. By forming a rectangular groove 22 having a width of about 0.1 mm and a depth of about 0.05 mm in a line shape, a line-shaped connection portion 21 having a width of about 0.3 mm was produced.

  A solder layer having a thickness of about 0.02 mm was formed on the surface of the wiring member 2 according to Example 1 and Example 2 by the dipping method.

<Step 4> Wiring material connecting step Next, a resin-type adhesive containing a thermosetting epoxy resin is dispensed by a dispenser or the like on the connection electrodes on the light receiving surface side and the back surface side of the samples of Example 1 and Example 2. Applied. Note that the adhesive imparts conductivity by including nickel particles having a volume ratio of about 5% in the resin. Next, the wiring material created in step 3 was placed on the adhesive applied to each sample.

  Further, in the samples of Example 1 and Example 2, the amount of the adhesive was adjusted so that the adhesive entered the inside of the groove 22 existing between the connecting portions 21 and 21.

And the wiring material 2 distribute | arranged on the solar cell was pinched | interposed one by one by the heating part from the upper and lower sides, it heated, applying a predetermined pressure, and the wiring material 2 and the solar cells 31, 32 ... were connected. At this time, for the samples of Examples 1 and 3, the pressure was adjusted so that the wiring material and the connection electrode were electrically connected via the conductive particles in the adhesive. For the sample of Example 2, the pressure was adjusted so that the protrusion of the connection electrode was recessed in the solder layer formed on the surface of the wiring material. Each pressure was obtained in advance by a preliminary experiment.
(Comparative example)
A sample of a comparative example in the same manner as the sample of Example 1 except that the wiring material is a copper thin plate having a width of about 1.5 mm, a thickness of about 0.15 mm, and a length of about 255 mm covered with a solder layer. It was created.
(result)
About the solar cell module which concerns on Example 1, Example 2, and a comparative example, each production yield was computed. In addition, the production yield was calculated by determining that the solar cell cracks and cracks that occurred when the wiring material was connected could be visually confirmed. Moreover, about the solar cell module which concerns on Example 1, 2 and a comparative example, the temperature cycle test (JIS C8917) was done in the period of 3 times. And the deterioration rate of the output of the solar cell module which generate | occur | produced by the temperature cycle test was computed from ratio of the conversion efficiency before a test, and the conversion efficiency after a test. The results are shown in Table 1.

同表に示すように、比較例に対して実施例１、２の歩留りは向上した。比較例において、配線材２と接続電極４Ｂ、４１Ｂを接続する際に印加される圧力は、配線材２の中央部近傍に集中する。これに対して、実施例１、２では、配線材２の複数の接続部２１により配線材２の短手方向Ｙの端部においても接続電極４Ｂ、４１Ｂとの接続が可能なため、接続電極４Ｂ、４１Ｂに印加される圧力を分散して太陽電池に加えることができる。よって、実施例１、２において、太陽電池割れやクラックの発生を抑制することができたと考えられる。

As shown in the table, the yields of Examples 1 and 2 were improved with respect to the comparative example. In the comparative example, the pressure applied when connecting the wiring member 2 and the connection electrodes 4 </ b> B and 41 </ b> B is concentrated near the center of the wiring member 2. On the other hand, in the first and second embodiments, the connection electrodes 4B and 41B can be connected to the end portions in the short direction Y of the wiring member 2 by the plurality of connecting portions 21 of the wiring member 2. The pressure applied to 4B and 41B can be dispersed and applied to the solar cell. Therefore, in Example 1, 2, it is thought that generation | occurrence | production of the solar cell crack and the crack was able to be suppressed.

Further, the deterioration rate was improved in Examples 1 and 2 with respect to the comparative example. This is because the connection is made by the plurality of connecting portions 21 in the first and second embodiments, so that the connection reliability between the connection electrodes 4B and 41B and the wiring member 2 can be improved. Further, in the first and second embodiments, the adhesive material has entered the inside of the groove 22 existing between the connecting portions 21 and 21. For this reason, the connection strength between the wiring member 2 and the connection electrode 4B is increased as compared with the conventional case. For these reasons, in Example 1 and Example 2, output reduction in the temperature cycle test could be suppressed, so it is considered that the deterioration rate was improved.
<< Third Embodiment >>
A third embodiment of the present invention will be described with reference to FIG. In the following description, descriptions of the same or similar parts as in the first embodiment are omitted.

(Structure of wiring material)
FIG. 10 is a cross-sectional view of the wiring member 2 according to the present embodiment cut along the short direction Y. As shown in the figure, the wiring member 2 has a plurality of connecting portions 21, 21... Provided in the short direction Y so as to be separated from each other with a gap 221 formed at a predetermined interval. Layer 23. In the present embodiment, unlike the first and second embodiments, the connecting member 24 is not formed in the wiring member 2.

(Function and effect)
Also in the present embodiment, as in the first embodiment, the wiring member 2 and the connection electrode 4B can be electrically connected via the conductive particles 7a over almost the entire surface of each connection portion 21. An increase in resistance can be suppressed.

  Moreover, since the output fall after use for a long time can be suppressed, the solar cell module with improved reliability can be provided.

  Furthermore, the generation of defects such as cracks, chips or cracks in the solar cell can be suppressed, and the yield can be improved.

In the present embodiment, similarly to the second embodiment, the protrusion 45 of the connection electrode 4B may be directly inserted into the conductive layer 23 of the wiring member 2 to make electrical connection. In this case, the same effect can be obtained.
(Other embodiments)
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.

  In the embodiment, the solar cells are electrically connected on the light receiving surface side and the back surface side of the adjacent solar cells, but the back contact type solar cell that enables connection between the solar cells only on the back surface side is used. The solar cells may be connected only on the back surface side of the solar cells. In such a back contact type solar cell, an electrode on one conductive side and an electrode on the opposite conductive side are formed on the back surface side. Therefore, the connection part 21 of the wiring member 2 may be formed only on the surface corresponding to the connection electrode of the wiring member 2 without being provided on both the upper surface side and the lower surface side of the wiring member. Even in this case, the wiring member 2 and the connection electrode can be electrically connected over the entire surface of the conductive layer 23 provided in the plurality of connection portions 21, and the same effects as those of the above-described embodiment can be obtained. Can do.

  Further, in the first and second embodiments, the connection between the adjacent solar cells is made by the integral wiring member 2, but the present invention is not limited to this, and a plurality of wiring members may be used. For example, a first wiring material is disposed on the connection electrode 4B on the light receiving surface side of one adjacent solar cell, a second wiring material is disposed on the connection electrode 41B on the back surface side of the other solar cell, The first wiring member and the second wiring member may be electrically connected by the third wiring member. In this case, one having a plurality of connection portions only on the surface of the first and second wiring members facing the connection electrodes can be used. Even in such a case, by providing a conductive layer in the connection portion provided on the side facing the connection electrode of the wiring material, the electrical connection between the wiring material 2 and the connection electrode can be achieved over the entire surface of the conductive layer 23. It becomes possible, and the same effect as the above-mentioned embodiment can be produced.

It is a conceptual diagram of the solar cell module which concerns on 1st Embodiment. It is sectional drawing of the wiring material of the solar cell module which concerns on 1st Embodiment. It is a top view of the solar cell which concerns on 1st Embodiment. It is a top view explaining the connection relation of the solar cell and wiring material of the solar cell module which concerns on 1st Embodiment. It is sectional drawing explaining the connection relation of the solar cell and wiring material of the solar cell module which concerns on 1st Embodiment. It is sectional drawing explaining the connection relation of the solar cell and wiring material of the solar cell module which concerns on a comparative example. It is a top view of the wiring material of the solar cell module which concerns on the modification of 1st Embodiment. It is sectional drawing of the wiring material of the solar cell module which concerns on the modification of 1st Embodiment. It is sectional drawing explaining the connection relation of the solar cell and wiring material of the solar cell module which concerns on 2nd Embodiment. It is sectional drawing of the wiring material of the solar cell module which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell module 2 Wiring material 21 Connection part 22 Groove 221 Gap 23 Conductive layer 24 Connection part 31,32,33,34 Solar cell 4,41 Current collection electrode 4A, 41A Fine wire electrode 4B, 41B Connection electrode 5 Photoelectric conversion part 7 Adhesive

Claims (4)

A plurality of solar cells having connection electrodes on the surface and arranged along the arrangement direction;
A wiring member electrically connected on the connection electrode and having the arrangement direction as a longitudinal direction;
An adhesive for bonding the wiring material and the connection electrode;
With
The wiring material is
A plurality of connecting portions provided to be separated from each other in a short direction perpendicular to the longitudinal direction on the side of the wiring member facing the surface of the connection electrode;
A connecting portion for connecting the plurality of connecting portions;
A convex conductive layer formed by forming a conductive material only on a flat surface opposite to the surface of the connection electrode of the plurality of connection portions in a state where the plurality of connection portions and the coupling portion are formed;
Including
The adhesive is
Resin,
Conductive particles;
Including
The adhesive is filled in a gap separating adjacent connecting portions;
The said wiring material is electrically connected with the said connection electrode through the said electroconductive particle, The solar cell module characterized by the above-mentioned. The connection electrode has a protrusion on the surface facing the conductive layer,
2. The solar cell module according to claim 1, wherein the wiring member is electrically connected to the connection electrode when the protrusion is recessed into the conductive layer.   The solar cell module according to claim 1, wherein the conductive layer is formed by a plating method. The solar cell module according to claim 1, wherein the conductive layer is formed by a dip method.

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