JP2005129773A - Solar cell module and wiring for connecting solar cell element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell module which can reduce an interval between solar cells while avoiding the cracking of solar cell elements and preventing the disconnection of an inner lead from an electrode, and also to provide wiring for connecting the solar cell elements. <P>SOLUTION: The solar cell module includes a plurality of solar cell elements having electrodes on surfaces of light reception and light non-reception sides and electrically connected to one another. An inner lead is provided to each of the light reception and non-reception side electrodes to be extended outwards of the outer peripheral end edge of the solar cell element. A conductive connection member having nearly the same thickness as the solar cell elements is provided between the inner lead connected to the light reception surface side of one solar cell element and the inner lead connected to the light non-reception surface side of another solar cell element adjacent thereto to electrically connect the inner leads. Consequently, when the light reception and non-reception side electrodes of the adjacent solar cell elements are connected by the inner leads, an interval between the adjacent solar cell elements can be prevented from being reduced. Even when the inner leads are bent, stress can be avoided from being applied to between the inner leads and the electrodes or to the outer peripheral end edge of the solar cell element, thus solving the problem of the generation of cracks. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention particularly relates to a solar cell module in which a plurality of solar cell elements are connected to an inner lead by a conductive connecting member, and a wiring for connecting solar cell elements for connecting the plurality of solar cell elements to each other.

  Solar cell elements are often manufactured using a single crystal silicon substrate or a polycrystalline silicon substrate. For this reason, a solar cell element is weak to a physical impact, and when a solar cell element is attached outdoors, it is necessary to protect this from rain. Moreover, since the electrical output generated by one solar cell element is small, it is necessary to connect a plurality of solar cell elements in series and parallel so that a practical electrical output can be taken out. For this reason, a solar cell module is usually manufactured by connecting a plurality of solar cell elements and enclosing with a filler mainly composed of a translucent substrate and ethylene vinyl acetate copolymer (EVA). .

  FIG. 9 shows an example of a conventional method for connecting solar cell elements. 1 is a solar cell element, 2 is a light receiving surface side electrode, 3 is a non-light receiving surface side electrode, and 4 is an inner lead.

  The solar cell element 1 is made of, for example, single crystal silicon or polycrystalline silicon having a thickness of about 0.3 to 0.4 mm and a size of about 100 to 150 mm square. On both surfaces, a light receiving surface side electrode 2 and a non-light receiving surface side electrode 3 for taking out outputs are formed. As a forming method, a screen printing method is generally used for cost reduction, and printing is performed by printing a silver paste on the surface of the solar cell element 1 and baking it. And in order to make it easy to connect the surface of the light-receiving surface side electrode 2 and the non-light-receiving surface side electrode 3 with the inner lead 4 in order to connect solar cell elements, and to ensure the long-term reliability of the solar cell element 1. Further, it is covered with a solder layer (not shown). In general, the inner lead is made of a copper foil having a thickness of about 0.1 to 0.3 mm which is coated with solder on the entire surface.

  Moreover, FIG. 10 is a figure which shows an example of the electrode provided in the light-receiving surface side and non-light-receiving surface side of a solar cell element. The light-receiving surface side electrode 2 shown in FIG. 10A includes a bus bar electrode 7 for attaching the inner lead 4 and a finger electrode 8 for current collection, and the non-light-receiving surface side electrode 3 shown in FIG. It comprises a bus bar electrode 7 and a current collecting electrode 9 made of aluminum.

When the solar cell elements 1 are connected in series, the inner lead 4 attached to the light receiving surface side electrode 2 of one solar cell element 1 is connected to the non-light receiving surface side electrode 3 of another adjacent solar cell element 1. To do. The connection of the inner leads is performed by heating and melting the solder (see Patent Document 1).
JP 1999-31820 A JP 2001-60710 A JP 2002-359388 A

  In this conventional solar cell module, in order to draw the inner lead 4 from the light-receiving surface side of one solar cell element to the non-light-receiving surface side of another solar cell element, the interval between adjacent solar cell elements 1 is 2 to 5 mm. The total solar cell element area relative to the area of the solar cell module cannot be increased, and module materials such as glass, resin, and aluminum frame cannot be reduced, which is one of the causes of high costs. .

  In order to improve this, if the interval between the adjacent solar cell elements 1 is reduced, the inner lead 4 is bent greatly, so that the inner lead 4 and the light receiving surface side electrode 2, the non-light receiving surface side electrode 3, or the sun. Stress is applied to the outer peripheral edge of the battery element 1. Therefore, there is a problem that the inner lead 4 is detached from the electrode, the outer peripheral edge of the solar cell element 1 is cracked, or a crack is generated from this portion. Moreover, since the possibility that the inner lead 4 comes into contact with the outer peripheral edge of the adjacent solar cell element 1 is increased, the current leaks.

  In addition, since the solar cell module is usually installed outdoors, it is subject to daily temperature cycle stress, and the inner lead 4 may be disconnected at the bent portion because the temperature stress is concentrated at the bent portion. Long-term reliability was not obtained.

  Furthermore, in recent years, the thickness of the solar cell element 1 has been reduced from the viewpoint of cost reduction, and the coating of the solder layer of the electrode has been reduced from the viewpoint of environmental problems. Since the lead 4 is easily detached from the electrode, it has been desired to reduce the stress accompanying the inner lead connection.

  Further, Patent Document 2 discloses that a solar cell element interval can be narrowed by a solar cell connection method in which a plurality of solar cells are electrically connected by a connection metal fitting made of a conductive metal and also mechanically connected. ing. However, when this connection fitting is used, it is necessary to sandwich the solar cell element by applying a certain amount of stress. As a result, the daily temperature cycle may apply more stress than necessary to the metal fittings or weaken the stress, which may lead to cracks in the solar cell elements and poor connection, resulting in problems with long-term reliability. there were.

  Further, in Patent Document 3, in a solar cell module in which a plurality of solar cell elements are connected by inner leads, separate inner leads are connected to the light receiving surface side electrode and the non-light receiving surface side electrode of the solar cell element, and one solar By connecting the inner lead connected to the light receiving surface side of the battery element and the inner lead connected to the non-light receiving surface side of another adjacent solar cell element, the solar cells adjacent to each other are not pulled A technique capable of avoiding element cracking is disclosed. However, in this case, since it is necessary to bend at least one of the inner leads, there is a problem in that stress is applied between the inner lead and the electrode, and cracks and cracks are generated.

  The present invention has been made in view of such problems of the prior art, and does not cause cracking or cracking of the solar cell element, and the interval between the solar cells is reduced without the inner lead being detached from the electrode. An object of the present invention is to provide a solar cell module and a wiring for connecting solar cell elements.

  In order to achieve the above object, a solar cell module according to claim 1 is a solar cell module formed by electrically connecting a plurality of solar cell elements each having a light receiving surface side electrode and a non-light receiving surface side electrode. Each of the light receiving surface side electrode and the non-light receiving surface side electrode includes an inner lead that is connected to each of the light receiving surface side electrode and the outer peripheral edge of the solar cell element, and one solar cell. Between the inner lead connected to the light receiving surface side of the element and the inner lead connected to the non-light receiving surface side of another adjacent solar cell element, the thickness of these solar cell elements is approximately the same. These inner leads are electrically connected to each other by interposing a conductive connecting member having

  Moreover, in the said solar cell module, it is preferable that the maximum value of the width | variety when the connection part of the said connection member and the said inner lead is cut | disconnected in the longitudinal direction of this inner lead is larger than the thickness of this inner lead.

  In the solar cell module, it is preferable that the maximum value of the width of the connecting member when cut in the short direction of the inner lead is equal to or larger than the width of the inner lead in the short direction.

  In the solar cell module, it is preferable that an insulating member is interposed between the connection member and the solar cell element.

  Moreover, in the said solar cell module, it is preferable that the connection part of the said connection member and an inner lead is coat | covered with the insulating material.

  According to a sixth aspect of the present invention, there is provided a wiring for connecting solar cell elements for electrically connecting a plurality of solar cell elements having a light receiving surface side electrode and a non-light receiving surface side electrode. A first inner lead connected to the light receiving surface side electrode of one solar cell element, a second inner lead connected to the non-light receiving surface side electrode of the other solar cell element, and these solar cells A conductive connecting member having substantially the same thickness as the element, and electrically connecting the connecting member between one end of the first inner lead and one end of the second inner lead. As one.

  In the connection wiring, the maximum value of the width when the connection portion between the connection member and the first inner lead or the second inner lead is cut in the longitudinal direction of any of the inner leads. However, the thickness is preferably larger than the thickness of the inner lead.

  In the connection wiring, it is preferable that the maximum value of the width of the connection member when cut in the short direction of the inner lead is equal to or larger than the width of the inner lead in the short direction.

  In the connection wiring, it is preferable that the connection member is covered with an insulating member.

  In the connection wiring, it is preferable that a connection portion between the connection member and the first inner lead or the second inner lead is covered with an insulating member.

  According to the present invention, the inner lead formed on the light-receiving surface side electrode and the non-light-receiving surface side electrode of the solar cell element is connected to each of the light-receiving surface side electrode and the non-light-receiving surface side electrode. Between the inner leads connected to the light receiving surface side of one solar cell element and the inner leads connected to the non-light receiving surface side of another adjacent solar cell element. By interposing a conductive connecting member having a thickness substantially the same as the thickness and electrically connecting the inner leads to each other, the inner lead and the light receiving surface side electrode and the non-light receiving surface side electrode are connected. In addition, the stress applied to the outer peripheral edge of the solar cell element can be relieved, and therefore, problems such as disengagement of the inner lead electrode can be prevented without causing the solar cell element to crack or crack. It is possible. In addition, the space between adjacent solar cell elements can be reduced, the total solar cell element area relative to the area of the solar cell module can be increased, and the cost can be reduced by reducing module materials such as glass, resin, and aluminum frame. It is. In addition, disconnection due to temperature cycle stress of the inner lead can be prevented, and long-term reliability is improved. In addition, by covering the part of the connecting member with an insulating member, there is an effect in reducing leakage due to contact.

  Hereinafter, an embodiment of a solar cell module according to claim 1 of the present invention will be described first. FIG. 1 is a cross-sectional view showing an embodiment of the solar cell module of the present invention. In FIG. 1, 1 is a solar cell element, 2 is a light receiving surface side electrode, 3 is a non-light receiving surface side electrode, 4 is an inner lead, and 5 is a conductive connecting member.

The solar cell element 1 is made of single crystal silicon, polycrystalline silicon, or the like having a thickness of about 0.3 to 0.4 mm and a size of about 100 to 150 mm square. The solar cell element 1 has an n-type region and a p-type region, and a semiconductor junction is formed at an interface portion between the n-type region and the p-type region. In this n-type region, a p-type silicon substrate is placed in a diffusion furnace and heated in phosphorus oxychloride (POCl ₃ ) to diffuse phosphorus atoms over the entire surface of the silicon substrate, resulting in a thickness of 0.2 It is formed to about 0.5 μm. Thereafter, the diffusion layers on the side surface and the bottom surface are removed.

  An antireflection film (not shown) made of, for example, a silicon nitride film is formed on the light receiving surface side of the solar cell element 1. Such an antireflection film is formed by, for example, a plasma CVD method or the like.

  A light-receiving surface side electrode 2 is formed on the surface portion of the n-type region. As shown in FIG. 10A, the light-receiving surface side electrode 2 includes a bus bar electrode 7 for connecting the inner lead 4 and a current collecting finger electrode 8 formed by crossing the bus bar electrode 7 and branching. And. Two or three bus bar electrodes 7 are formed in parallel over substantially the entire length of the solar cell element 1, and a plurality of finger electrodes 8 are formed over the entire length of the solar cell element 1 so as to intersect the bus bar electrode 7. . The bus bar electrode 7 is formed with a width of about 2 mm, for example, and the finger electrode 8 is formed with a width of about 0.2 mm, for example. Such a light receiving surface side electrode 2 is formed, for example, by screen-printing a paste containing silver powder, glass frit, and organic vehicle, baking it at a temperature of about 700 to 800 ° C., and covering the whole with a solder layer.

  A non-light-receiving surface side electrode 3 is formed on the non-light-receiving surface side of the solar cell element 1. As shown in FIG. 10B, the non-light-receiving surface side electrode 3 also includes a bus bar electrode 7 and a current collecting electrode 9 formed on the entire surface of the non-light-receiving surface.

  The bus bar electrode 7 of the non-light-receiving surface side electrode 3 is also made of, for example, a paste containing silver powder, glass frit and organic vehicle, and the current collecting electrode 9 is made of, for example, a paste containing aluminum powder, glass frit and organic vehicle. It is formed by screen printing, baking at a temperature of about 700 to 800 ° C., and covering the whole with a solder layer. Further, the non-light-receiving surface side electrode 3 does not have the above-described structure, and may have a structure including a bus bar electrode 7 and finger electrodes 8 similar to those of the light-receiving surface side electrode 2.

  In the solar cell module according to the present invention, as shown in FIG. 1, the light receiving surface side electrode 2 and the non-light receiving surface side electrode 3 of the solar cell element 1 are respectively provided with a light receiving surface side inner lead 4a and a non-light receiving surface side inner lead. Two kinds of inner leads having a 4b elongated shape are connected one by one, and each of these inner leads 4 (4a, 4b) extends outward from the outer peripheral edge of the solar cell element 1.

  Further, in FIG. 1, the light receiving surface side inner lead 4a connected to the light receiving surface side of the left solar cell element 1, and the non-light receiving surface side inner lead connected to the non-light receiving surface side of the adjacent right solar cell element 1. 4b, a conductive connecting member 5 is interposed between the inner lead 4 and the outer lead edge of the solar cell element 1, and the two types of inner leads 4 are connected to each other. Electrically connect to The connecting member 5 has substantially the same thickness as the solar cell element 1.

  In order to reduce the resistance component of the solar cell element, the inner lead 4 is preferably overlapped with almost all the bus bar electrodes.

  As a connection method, for example, the inner lead 4 is attached to the connection member 5 at the full length of the bus bar electrode or at a plurality of points by heat welding such as hot air.

  In the present invention, since the inner leads 4 are connected by the connecting member 5 having the same thickness as the solar cell element 1 as described above, the solar cell elements 1 can be connected to each other without bending the inner lead 4. The stress applied between the lead 4 and the light receiving surface side electrode 2 or the non-light receiving surface side electrode 3 or on the outer peripheral edge of the solar cell element 1 can be relaxed. Therefore, problems such as disengagement of the electrode of the inner lead can be prevented without causing cracks or cracks in the solar cell element. Moreover, the space | interval of the adjacent solar cell element 1 can be made small, the total solar cell element area with respect to the area of a solar cell module can be raised, and the cost reduction by reduction of module materials, such as glass, resin, and an aluminum frame, can be carried out. Is possible. Further, disconnection due to temperature cycle stress of the inner lead can be prevented, and the long-term reliability is excellent.

  Moreover, it is desirable that the connecting member 5 be disposed between two adjacent solar cell elements 1 in parallel with the outer peripheral end portions of the respective elements, whereby the connecting member 5 and the solar cell element 1 come into contact with each other. Current leakage can be reduced.

  As the inner lead 4 connected to the light-receiving surface side electrode 2 and the non-light-receiving surface side electrode 3, for example, a copper foil having a thickness of about 100 to 300 μm with the entire surface coated with a solder of about 20 to 70 μm can be used. .

  The widths of the light receiving surface side inner leads 4a connected to the light receiving surface side and the non-light receiving surface side inner leads 4b connected to the non-light receiving surface side are not necessarily the same. The width of the light receiving surface side inner lead 4a is preferably equal to or less than the width of the bus bar electrode so as not to cause a shadow on the light receiving surface of the solar cell element 1 by itself. On the other hand, the width of the inner lead 4b on the non-light-receiving surface side can be increased to increase the cross-sectional area and reduce the electrical resistance because there is no such problem. For example, the width is about 5 mm. Since it can be formed and the width can be increased, the thickness of the inner lead can be reduced.

  The material of the conductive connection member 5 is not particularly limited. However, when a material different from that of the inner lead 4 is used, stress is applied to the connection portion due to the difference in thermal expansion coefficient, and there is a problem in reliability. Therefore, it is preferable to use the same material as the inner lead 4 such as copper when a copper foil is used for the inner lead 4 and silver when a silver foil is used. Further, the connecting member 5 is not limited to one type of material, and may be a plurality of types, for example, copper coated with solder.

  Next, the size relationship between the connecting member 5 and the inner lead 4 will be described with reference to FIG.

  First, with respect to the size of the connecting portion between the connecting member 5 and the inner lead 4, that is, the size of the portion surrounded by the dotted line in FIG. 11, the width a when cut in the longitudinal direction of the inner lead 4 is the inner lead 4. The thickness c is preferably larger than the thickness c. By setting it as this range, the contact area of the inner lead 4 and the connection member 5 becomes large, and the electrical resistance between members can be lowered. Further, there is an advantage that the inner lead 4 and the connecting member 5 are not detached and the workability can be improved. Specifically, for example, the width of the connection member 5 is preferably formed to be about 0.3 to 1.0 mm. If the value is smaller than this value, there is a problem that the electrical resistance increases and the conversion efficiency decreases. When the connecting portion between the connecting member 5 and the inner lead 4 has an irregular shape, the maximum value of the width when cut in the longitudinal direction of the inner lead 4 is regarded as the width a.

  Further, it is preferable that the width b of the connecting member 5 when cut in the short direction of the inner lead 4 is equal to or larger than the width d of the inner lead 4 in the short direction. If it is out of this range, there is a risk that the inner lead 4 may be detached from the connecting member 5 by bending the portion of the inner lead 4 that is not in contact with the connecting member 5 in a subsequent process, for example, a laminating process. By setting the range, it is possible to prevent the inner lead 4 from coming off from the connecting member 5 and to improve the yield. If the width of the inner lead is different between the light receiving surface side and the non-light receiving surface side, the width of the connecting member 5 may be adjusted to the width of the wider inner lead. Alternatively, the width on the light receiving surface side and the width on the non-light receiving surface side of the connection member 5 may correspond to the width of the inner lead corresponding to each. When the connecting member 5 has an irregular shape, the maximum width when the inner lead 4 is cut in the short direction is regarded as the width b.

  FIG. 2 is a perspective view showing an example of a connection member used in the present invention. The shape of the connecting member 5 only needs to have the same thickness as that of the solar cell element 1. For example, the connecting member 5 may have a rectangular parallelepiped shape as shown in (a) or an elliptical shape that contacts the inner lead as shown in (b). It may be a shape.

  FIG. 3 shows a perspective view when an insulating member is used. Thus, it is preferable that the insulating member 6 is interposed between the connecting member 5 and the solar cell element 1. At this time, the insulating member 6 is made of, for example, an epoxy resin, an acrylic resin, an EVA resin, glass, a ceramic plate, and a resin plate, and has a thickness of about 100 to 500 μm. As shown in FIG. 3 (a), the insulating member 6 may be provided only in a portion adjacent to the solar cell element 1 of the connecting member 5, or as shown in FIG. 3 (b), the insulating member is provided around the connecting member 5. 6 may be covered. If it does in this way, the current leak at the time of the connection member 5 contacting with the other solar cell element 1 which adjoins by an operation mistake etc. can be prevented.

  Furthermore, it is preferable to cover the connecting portion between the connecting member 5 and the inner lead 4 with an insulating material. As shown in FIG.3 (c), you may coat | cover the part adjacent to the solar cell element 1 with respect to both the connection member 5 and the inner lead 4, and as shown in FIG.3 (d), the connection member 5 may be covered. The entire connecting portion of the inner lead 4 may be covered. In this way, the insulating member is covered not only around the connection member 5 but also at the connection portion with the inner lead 4, so that current leakage caused when the inner lead 4 comes into contact with another adjacent solar cell element 1 due to an operation error. It is possible to further enhance the effect of preventing this.

  The state which connected the solar cell element using the insulating member mentioned above in FIG. 4 is shown.

  Fig.4 (a) is sectional drawing which shows the state which connected the solar cell element 1 using the connection member 5 shown to Fig.3 (a). In this case, since the insulating member 6 is interposed between the connecting member 5 and the solar cell element 1, the inner lead 4 is connected with the solar cell element 1 and the connecting member 5 in contact with each other in advance. Is possible. In this way, since the connection member 5 and the solar cell element 1 are in contact with each other in advance, the connection work becomes easy, and the solar cell elements 1 can be arranged close to each other. The total solar cell element area relative to the area can be increased.

  FIG. 4B is a cross-sectional view showing a state in which the solar cell element 1 is connected using the connecting member 5 and the inner lead 4 shown in FIG. In this case, since the insulating member 6 is coated on the connection member 5 and the inner lead 4 at a portion adjacent to the solar cell element 1, the solar cell element 1 and the connection member 5 are in contact with each other in advance. Thus, the inner lead 4 can be connected. In this way, since the connecting member 5 and the solar cell element 1 are in contact with each other in advance, the connection work is also easy, and the solar cell elements 1 can be arranged close to each other. The total solar cell element area relative to the area can be increased.

  Next, an embodiment of the solar cell element connection wiring according to claim 6 of the present invention will be described.

  FIG. 5 is a diagram showing an embodiment of the connection wiring for solar cell elements of the present invention. FIG. 5 (a) is a perspective view of one embodiment of the connection wiring for solar cell elements, and FIG. It is sectional drawing when a solar cell element is connected by (a).

  As shown in FIG. 5A, the solar cell element connection wiring 17 of the present invention is interposed between the first inner lead 14a, the second inner lead 14b, and one end of each inner lead. The conductive connecting member 15 that is electrically connected and integrated together is combined with each other. And as shown in FIG.5 (b), the other end part of the 1st inner lead 14a is connected to the light-receiving surface side electrode 2 of one solar cell element, and the other end part of the 2nd inner lead 14b is It is connected to the non-light-receiving surface side electrode 3 of the other solar cell element, and these solar cell elements are electrically connected. Further, the conductive connection member 15 has substantially the same thickness as these solar cell elements.

  As the first and second inner leads 14 (14a, 14b), for example, a copper foil having a thickness of about 100 to 300 μm in which the entire surface is coated with a solder of about 20 to 70 μm can be used. Further, the material of the conductive connection member 15 is not particularly limited. However, when a material different from that of the first and second inner leads 14 is used, the connection portion is caused by the difference in thermal expansion coefficient. Since the stress is applied to the surface, there is a possibility that a problem in reliability may occur. Therefore, the same material as the inner lead 14 is used, such as copper when the copper foil is used for the inner lead 14 and silver when the silver foil is used. It is preferable to use Further, the connecting member 15 is not limited to one type of material, and a plurality of types, for example, a composite material in which solder is coated on copper may be used.

  As a method for manufacturing the solar cell element connection wiring 17 according to the present invention, the inner lead 14 and the connection member 15 may be connected by thermal welding such as hot air.

  As a method of connecting the solar cell elements with the connection wiring 17 of the solar cell elements, for example, solar cells that connect the end portions of the first and second inner leads 14 by hot welding such as hot air, respectively. Connect at the full length of the bus bar electrode of the element or at multiple points.

  Since the solar cell elements can be connected to each other without bending the inner lead by using the connection wiring 17, the first and second inner leads 14, the light receiving surface side electrode 2, and the non-light receiving surface side electrode 3 are connected. In addition, the stress applied to the outer peripheral edge of the solar cell element 1 can be relaxed. Therefore, it is possible to prevent problems such as detachment of the first and second inner leads 14 from the electrode without generating cracks or cracks in the solar cell element.

  Moreover, the space | interval of the adjacent solar cell element 1 can be arrange | positioned closely, the total solar cell element area with respect to the area of a solar cell module can be raised, and by reduction of module materials, such as glass, resin, and an aluminum frame Cost reduction is possible. Furthermore, disconnection due to temperature cycle stress of the inner lead 14 can be prevented, and the long-term reliability is excellent.

  In addition, when the first and second inner leads 14 are disposed, the connecting member 15 is desirably disposed between two adjacent solar cell elements in parallel with the outer peripheral end of each element. If it makes it, it is effective also in reducing the current leak by the contact of the connection member 15 and the solar cell element 1. Further, since the connecting member 15 in the present invention is smaller than the first and second inner leads 14, it is more desirable to prepare the connecting wiring 17 in advance so that the workability is improved.

  Also in the connection wiring 17 of the solar cell element of the present invention, the magnitude relationship between the connection member 15 and the first and second inner leads is the same as that described in FIG. That is, the width when the connecting portion between the connecting member 15 and the first inner lead 14 a or the second inner lead 14 b is cut in the longitudinal direction of any one of the inner leads 14 is the thickness of the inner lead 14. Larger is preferred. By setting it as this range, the contact area of these inner leads 14 and the connection member 15 becomes large, and the electrical resistance between members can be lowered. Furthermore, there is an advantage that the inner lead 14 and the connecting member 15 are not detached and the workability can be improved. Specifically, for example, the width of the connection member 15 is preferably formed to be about 0.3 to 1.0 mm. If the width is made smaller than this value, the electrical resistance increases and there is a problem that the conversion efficiency decreases. In addition, when the connection part of the connection member 15 and the inner lead 14 has an irregular shape, the maximum value of the width when cut in the longitudinal direction of the inner lead 14 is regarded as a reference.

  Further, in the solar cell element connection wiring 17 of the present invention, it is preferable that the width of the connecting member when the inner lead 14 is cut in the short direction is equal to or larger than the width of the inner lead 14 in the short direction. If it is out of this range, there is a risk that the inner lead 14 may be detached from the connecting member 15 by bending the portion of the inner lead 14 that is not in contact with the connecting member 15 in a subsequent process, for example, a laminating process. In this range, the inner lead 14 can be prevented from coming off from the connecting member 15 and the yield can be improved. If the width of the inner lead 14 is different between the light receiving surface side and the non-light receiving surface side, the width of the connecting member 15 may be adjusted to the width of the wider inner lead. Alternatively, the width on the light receiving surface side and the width on the non-light receiving surface side of the connection member 15 may correspond to the width of the inner lead 14 corresponding to each. When the connection member 15 has an irregular shape, the maximum value of the width when the inner lead 14 is cut in the short direction is regarded as a reference.

  The perspective view of the example which provided the insulating member in the wiring for connection of the solar cell element of this invention in FIG. 6 is shown. Thus, in the connection wiring 17 of the solar cell element according to the present invention, the insulating member 16 is provided around the connection member 15 and the connection portion between the connection member 15 and the first inner lead 14a or the second inner lead 14b. Is preferably coated. At this time, the insulating member 16 is made of, for example, an epoxy resin, an acrylic resin, an EVA resin, glass, a ceramic plate, and a resin plate and has a thickness of about 100 to 500 μm.

  Then, as shown in FIG. 6A, only the portion adjacent to the solar cell element 1 of the connecting member 15 may be covered, or the insulating member 16 around the connecting member 15 as shown in FIG. May be coated. If it does in this way, the current leak at the time of the connection member 15 contacting with the other solar cell element 1 which adjoins by an operation mistake etc. can be prevented.

  Further, as shown in FIG. 6 (c), only the portion adjacent to the solar cell element 1 of the connecting member 15 of the connection wiring 17 and the inner lead 14 may be covered, as shown in FIG. 6 (d). The whole connecting portion between the connecting member 15 of the connection wiring 17 and the inner lead 14 may be covered with an insulating member. In this way, by covering the connection part of the inner lead 14 as well as the periphery of the connection member 15 with the insulating member, current leakage caused when the inner lead 14 comes into contact with another adjacent solar cell element 1 due to an operation error is prevented. The effect of preventing can be further enhanced.

  The state which connected the solar cell elements 1 using the wiring for a solar cell element which provided the insulation member mentioned above in FIG. 7 is shown. Fig.7 (a) is sectional drawing which shows the state which connected the solar cell elements 1 using the wiring 17 for a connection shown to Fig.6 (a). In this case, since the insulating member 16 is coated on the connection member 15 at a portion adjacent to the solar cell element 1, the connection wiring 17 is placed in a state where the solar cell element 1 and the connection wiring 17 are in contact with each other in advance. It is also possible to connect. If it does in this way, since a connection operation will become easy and the space | interval of the solar cell element 1 can be arranged close, the total solar cell element area with respect to the area of a solar cell module can be raised.

  FIG.7 (b) is sectional drawing which shows the state which connected the solar cell elements 1 using the wiring 17 for a connection shown in FIG.6 (c). In this case, since both the connection member 15 and the inner lead 14 of the connection wiring 17 are covered with the insulating member 16 in a portion adjacent to the solar cell element 1, the solar cell element 1 and the connection wiring 17 are connected in advance. It is also possible to connect in contact. If it does in this way, since a connection operation | work will also become easy and the space | interval of the solar cell element 1 can be packed and arrange | positioned, the total solar cell element area with respect to the area of a solar cell module can be raised.

  In addition, this invention is not limited to the above-mentioned embodiment, Many corrections and changes can be added to the said embodiment within the scope of the present invention. For example, the electrode shape is not limited to the above, and may be formed of only one kind of material such as silver, or a plurality of materials may be combined.

  Moreover, as long as the connection with the inner lead is possible, the electrode may not be covered with solder, and the connection method is not limited to heat welding such as hot air, and therefore the inner lead and the connection member are also not limited. You do not need to coat with solder. The same applies to the manufacturing method of the connection wiring, and for example, the connection may be made using a conductive paste.

  Further, with respect to the structure in which the conductive connecting member is covered with the insulating member, the insulating member 6 is interposed between the adjacent solar cell elements as shown in FIG. May be embedded and the inner leads may be connected.

It is sectional drawing which shows the solar cell module of this invention. (A), (b) is a perspective view which shows the example of the connection member concerning the solar cell module of this invention. (A)-(d) is a perspective view which shows the example connected with the example which provided the insulating member in the connection member concerning the solar cell module of this invention. (A), (b) is sectional drawing which shows the state which connected the solar cell element using the insulating member concerning the solar cell module of this invention. (A) is a perspective view of one Embodiment of the wiring for a solar cell element concerning this invention, (b) is sectional drawing when a solar cell element is connected by (a). (A)-(d) is a perspective view of the example which provided the insulating member concerning the wiring for connection of the solar cell element of this invention. (A), (b) is sectional drawing which shows the state which connected the solar cell element using the insulating member concerning the wiring for connection of the solar cell element of this invention. (A) is a top view which shows the state which connected the solar cell element using the insulating member concerning the solar cell module of this invention, (b) is sectional drawing which follows A-A '. It is sectional drawing which shows the conventional solar cell module. (A) is a figure which shows an example of the electrode shape by the side of the light-receiving surface of a solar cell element, (b) is a figure which shows an example of the electrode shape by the side of the non-light-receiving surface of a solar cell element. It is a figure for demonstrating the magnitude relationship of the connection member concerning the solar cell module of this invention, and an inner lead.

Explanation of symbols

1: Solar cell element 2: Light receiving surface side electrode 3: Non light receiving surface side electrode 4: Inner lead 4a: Light receiving surface side inner lead 4b: Non light receiving surface side inner lead 5: Connection member 6: Insulating member 7: Bus bar electrode 8 : Finger electrode 9: collecting electrode 14: inner lead 14a: first inner lead 14b: second inner lead 15: connecting member 16: insulating member 17: connecting wire a: cut in the longitudinal direction of the inner lead Width b: width of the connecting member when cut in the short direction of the inner lead c: thickness of the inner lead d: width of the inner lead in the short direction

Claims (10)

A solar cell module formed by electrically connecting a plurality of solar cell elements having a light receiving surface side electrode and a non-light receiving surface side electrode,
The light-receiving surface side electrode and the non-light-receiving surface side electrode are each provided with an inner lead that is connected one by one and extends outward from the outer peripheral edge of the solar cell element,
Between the inner leads connected to the light receiving surface side of one solar cell element and the inner leads connected to the non-light receiving surface side of another adjacent solar cell element, the thickness of these solar cell elements is approximately A solar cell module formed by electrically connecting these inner leads to each other with a conductive connecting member having the same thickness interposed therebetween. 2. The solar cell according to claim 1, wherein when the connecting portion between the connecting member and the inner lead is cut in the longitudinal direction of the inner lead, the maximum value of the width of the connecting portion is larger than the thickness of the inner lead. module. 3. The solar cell module according to claim 1, wherein when the connection member is cut in the short direction of the inner lead, the maximum value of the width of the connection member is equal to or greater than the width of the inner lead in the short direction. . The solar cell module according to any one of claims 1 to 3, wherein an insulating member is interposed between the connection member and the solar cell element. The solar cell module according to claim 1, wherein a connection portion between the connection member and the inner lead is covered with an insulating material. A solar cell element connection wiring for electrically connecting a plurality of solar cell elements having a light receiving surface side electrode and a non-light receiving surface side electrode,
A first inner lead connected to the light receiving surface side electrode of one solar cell element;
A second inner lead connected to the non-light-receiving surface side electrode of the other solar cell element;
A conductive connecting member having substantially the same thickness as these solar cell elements,
A connection wiring for a solar cell element in which the connection member is interposed between and electrically connected to one end of the first inner lead and one end of the second inner lead. The maximum value of the width when the connection portion between the connection member and the first inner lead or the second inner lead is cut in the longitudinal direction of any one of these inner leads is greater than the thickness of the inner lead. Wiring for connecting solar cell elements according to claim 6 which is large. The wiring for connecting solar cell elements according to claim 6 or 7, wherein the maximum width of the connecting member when cut in the short direction of the inner lead is equal to or greater than the width of the inner lead in the short direction. The wiring for connecting solar cell elements according to claim 6, wherein the connection member is covered with an insulating member around the connection member. The wiring for connecting solar cell elements according to any one of claims 6 to 9, wherein a connecting portion between the connecting member and the first inner lead or the second inner lead is covered with an insulating member.

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