JP6352331B2 - Solar cell and solar cell panel including the same - Google Patents

Description

  The present invention relates to a solar cell and a solar cell panel including the solar cell, and more particularly to a solar cell connected by a wiring material and a solar cell panel including the solar cell.

  In recent years, with the anticipated depletion of existing energy resources such as oil and coal, interest in alternative energy to replace them is growing. In particular, solar cells are in the spotlight as next-generation batteries that convert solar energy into electrical energy.

  Such solar cells are connected in series or in parallel by a plurality of ribbons, and are manufactured in the form of a solar cell panel by a packaging process for protecting the plurality of solar cells. Solar cell panels must generate power over a long period of time in various environments, and long-term reliability is greatly required. Conventionally, a plurality of solar cells are connected by a ribbon.

  However, if the solar cells are connected using a ribbon having a large width of about 1.5 mm, light loss may occur due to the large width of the ribbon. Therefore, it is necessary to reduce the number of ribbons arranged in the solar cell. In addition, there may be a problem that the mounting strength of the ribbon is not good or the bending of the solar cell increases due to the ribbon. For this reason, there is a limit in improving the output of the solar cell panel, the ribbon may come off or the solar cell may be damaged, and the reliability of the solar cell panel may be lowered.

  If the electrode structure is improved in order to prevent this, the efficiency of the solar cell is lowered, and the output of the solar cell panel can be lowered.

  An object of the present invention is to provide a solar cell capable of improving the output and reliability of the solar cell panel and a solar cell panel including the solar cell.

  A solar cell panel according to an embodiment of the present invention includes a semiconductor substrate, a solar cell having a conductive type region formed on or on the semiconductor substrate, and an electrode connected to the conductive type region, and the solar cell. A wiring member electrically connected to the electrode so as to connect the battery to another solar battery or to an external circuit. A plurality of finger lines each having an outermost finger line adjacent to an edge of the semiconductor substrate; and a second direction intersecting the first direction. And a bus bar line electrically connected to the bus bar. One end edge region is located at one end of the bus bar line adjacent to one side edge of the semiconductor substrate, and the other end edge region is located at the other end of the bus bar line adjacent to the other side edge of the semiconductor substrate. In each of the one end edge region and the other end edge region, the bus bar line has an opening inside, and an outermost end portion is disposed on the same line as the outermost finger line or on an outer side of the electrode portion. Have.

  The solar cell which concerns on the Example of this invention is provided with the semiconductor substrate, the conductive type area | region provided in the said semiconductor substrate or on the said semiconductor substrate, and the electrode connected with the said conductive type area | region. A plurality of finger lines including an outermost finger line adjacent to an edge of the semiconductor substrate; and a second direction intersecting the first direction. And a bus bar line electrically connected to the bus bar. One end edge region is located at one end of the bus bar line adjacent to one side edge of the semiconductor substrate, and the other end edge region is located at the other end of the bus bar line adjacent to the other side edge of the semiconductor substrate. In each of the one end edge region and the other end edge region, the bus bar line has an opening inside, and an outermost end portion is disposed on the same line as the outermost finger line or on an outer side of the electrode portion. Have.

  According to the present embodiment, by using the wiring material in the form of a wire, optical loss can be minimized by irregular reflection or the like, the pitch of the wiring material can be reduced, and the carrier movement path can be reduced. Thereby, the efficiency of the solar cell and the output of the solar cell panel can be improved. At this time, the edge distance of the first electrode can be limited according to the width of the wiring material, and the adhesion between the wiring material having the wire form and the first electrode can be improved. Thereby, damage to the solar cell that may occur when the wiring member is separated from the first electrode can be prevented, and the solar cell can have excellent electrical characteristics and excellent reliability. And the number of wiring materials can be limited according to the width | variety of a wiring material, and the output of a solar cell panel can be maximized.

  In the present embodiment, the electrode portion is located on the same line as the outermost finger line or on the outer side in the one end edge region and the other end edge region, thereby stably forming the connection structure with the wiring material. Can do. And the electric current produced | generated by the part of the electrode area | region adjacent to one end edge area | region and the other end edge area | region can be effectively transmitted to a wiring material via an electrode part. Accordingly, the current generated in the electrode region located in the portion adjacent to the one end edge region and the other end edge region can be effectively transmitted to the wiring member by the electrode portion. Therefore, even when one end edge region and the other end edge region are provided in order to improve the adhesive force or bonding force of the wiring member, it is possible to prevent a decrease in efficiency that may occur due to this. As a result, the efficiency of the solar cell can be improved and the output of the solar cell panel can be improved.

  In addition, by forming the electrode part located in the edge region at one end and the electrode part located in the edge region at the other end separately, the electrode structure can be simplified while stably forming the connection structure of the wiring material. it can.

It is a perspective view which shows the solar cell panel which concerns on the Example of this invention. It is sectional drawing which follows the II-II line of FIG. It is a fragmentary sectional view which shows an example of the solar cell contained in the solar cell panel of FIG. It is a fragmentary sectional view which shows the other example of the solar cell contained in the solar cell panel of FIG. It is a perspective view which shows schematically the 1st solar cell and 2nd solar cell which are connected by the wiring material in the solar cell panel of FIG. It is the perspective view and sectional drawing which show the wiring material before adhering to the electrode of the solar cell shown in FIG. It is sectional drawing which shows the wiring material adhering to the pad part of the electrode of the solar cell shown in FIG. It is a schematic sectional drawing of A part of FIG. It is a top view which shows the solar cell contained in the solar cell panel of FIG. 1, and the ribbon connected with this. It is the photograph which image | photographed the cross section of the solar cell which adhered the wiring material which has a separate width | variety. It is a graph which shows the result of having measured the adhesive force of the wiring material in the edge part of an electrode, changing the width | variety and edge distance of a wiring material. It is a graph which shows the output of the solar cell panel measured while changing the width | variety and number of wiring materials. It is a partial front top view of the solar cell panel which concerns on the other Example of this invention. It is a partial front top view of the solar cell panel concerning other examples of the present invention. It is a partial front top view of the solar cell panel concerning other examples of the present invention. It is a partial front top view of the solar cell panel concerning other examples of the present invention. It is a partial front top view of the solar cell panel concerning other examples of the present invention. It is a partial front top view of the solar cell panel concerning other examples of the present invention. It is a partial front top view of the solar cell panel concerning other examples of the present invention. It is a graph which shows the result of having measured the adhesive force, pulling the wiring material adhering to the solar cell panel using an experimental apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these examples, and may be modified in various forms.

  In the drawings, in order to clearly and simply explain the present invention, illustrations of parts not related to the description are omitted, and the same or very similar parts are denoted by the same reference numerals throughout the specification. In the drawings, for the sake of clearer explanation, the thickness, the width, etc. are shown enlarged or reduced, and the thickness, the width, etc. of the present invention are not limited to those in the drawings.

  Also, throughout the specification, when a part “includes” another part, unless otherwise specified, it does not mean that another part is excluded, but may include another part. Good. In addition, when a layer, a film, a region, a plate, or the like is “on” another part, this is not only in the case of “directly on” the other part, but also between other parts. This includes the case where the part is interposed. When a part such as a layer, a film, a region, or a plate is “directly on” another part, it means that no other part is located between them.

  Hereinafter, a solar cell and a solar cell panel including the solar cell according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a solar cell panel according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  Referring to FIGS. 1 and 2, the solar cell panel 100 according to the present embodiment includes a plurality of solar cells 150 and a wiring member 142 that electrically connects the plurality of solar cells 150. Furthermore, the solar cell panel 100 includes a sealing material 130 that encloses and seals the plurality of solar cells 150 and the wiring material 142 that connects the solar cells 150, a front substrate 110 that is positioned on the front surface of the solar cell 150 on the sealing material 130, And a back substrate 200 positioned on the back surface of the solar cell 150 on the sealing material 130. This will be described in more detail.

  First, the solar cell 150 may include a photoelectric conversion unit that converts the solar cell into electric energy, and an electrode that is electrically connected to the photoelectric conversion unit and collects and transmits current. The plurality of solar cells 150 may be electrically connected in series, parallel, or series-parallel with the wiring member 142. Specifically, the wiring member 142 electrically connects two adjacent solar cells 150 among the plurality of solar cells 150.

  The bus ribbon 145 is connected by the wiring member 142 to alternately connect both ends of the wiring member 142 of the solar cell 150 (that is, the solar cell string) forming one row. The bus ribbon 145 may be arranged in a direction intersecting with the end of the solar cell string. Such a bus ribbon 145 can connect adjacent solar cell strings, or can connect the solar cell strings to a junction box (not shown) that prevents reverse current flow. The material, shape, connection structure, and the like of the bus ribbon 145 may be variously modified, and the present invention is not limited thereto.

  The sealing material 130 may include a first sealing material 131 located on the front surface of the solar cell 150 and a second sealing material 132 located on the back surface of the solar cell 150. The first sealing member 131 and the second sealing member 132 block moisture and oxygen that may adversely affect the solar cell 150, and allow each element of the solar cell panel 100 to be chemically bonded. The back panel 200, the second sealing material 132, the solar cell 150, the first sealing material 131, and the front substrate 110 may be integrated in the solar cell panel 100 through a lamination process in which heat and / or pressure is applied in a state where the rear substrate 200, the first sealing material 131, and the front substrate 110 are arranged in order. it can.

  For the first sealing material 131 and the second sealing material 132, ethylene vinyl acetate copolymer resin (EVA), polyvinyl butyral, silicon resin, ester resin, olefin resin, or the like can be used. However, the present invention is not limited to this. Therefore, the first and second sealing members 131 and 132 may be formed by other methods other than lamination using various other substances. At this time, the first and second sealing members 131 and 132 are light transmissive so that light incident from the back substrate 200 or light reflected from the back substrate 200 can reach the solar cell 150.

  The front substrate 110 is provided on the first sealing material 131 and constitutes the front surface of the solar cell panel 100. The front substrate 110 may be made of a material having a strength capable of protecting the solar cell 150 from an external impact or the like and a light transmitting property capable of transmitting light such as sunlight. As an example, the front substrate 110 may be composed of a glass substrate or the like. At this time, the front substrate 110 can be composed of a tempered glass substrate so that the strength can be improved, and various modifications such as various substances that can improve various other characteristics can be included. is there. Alternatively, the front substrate 110 may be a sheet or film made of a resin or the like. That is, the present invention is not limited to the material of the front substrate 110, and the front substrate 110 may be composed of various materials.

  The back substrate 200 is a layer that is provided on the second sealing material 132 and protects the solar cell 150 on the back surface of the solar cell 150, and can perform functions of waterproofing, insulation, and ultraviolet blocking.

The back substrate 200 can have a strength capable of protecting the solar cell 150 from an external impact or the like, and can have a property of transmitting or reflecting light according to a desired structure of the solar cell panel 100. For example, in a structure in which light is incident from the back substrate 200, the back substrate 200 can have a light projecting material, and in a structure in which light is reflected by the back substrate 200, the back substrate 200 is a non-light projecting material or It may be made of a reflective material. As an example, the back substrate 200 may be in the form of a substrate such as glass, or may be in the form of a film or a sheet. For example, the back substrate 200 may be a TPT (Tedlar / PET / Tedlar) type, and is made of a polyvinylidene fluoride (PVDF) resin formed on at least one surface of polyethylene terephthalate (PET). Also good. Polyvinylidene fluoride is a polymer having a (CH ₂ CF ₂ ) n structure, and has a double fluorine molecular structure, and therefore has excellent mechanical properties, weather resistance, and ultraviolet resistance. The present invention is not limited to the material of the back substrate 200.

  With reference to FIG. 3, an example of the solar cell included in the solar cell panel according to the embodiment of the present invention will be described in more detail.

  FIG. 3 is a partial cross-sectional view showing an example of a solar cell included in the solar cell panel of FIG.

  Referring to FIG. 3, a solar cell 150 according to the present embodiment includes a semiconductor substrate 160 including a base region 10, conductive type regions 20 and 30 formed on or on the semiconductor substrate 160, and a conductive type region. And electrodes 42 and 44 connected to 20 and 30. Here, the conductivity type regions 20 and 30 may include a first conductivity type region 20 having a first conductivity type and a second conductivity type region 30 having a second conductivity type. A first electrode 42 connected to the first conductivity type region 20 and a second electrode 44 connected to the second conductivity type region 30 may be included. The solar cell 150 may further include a first passivation film 22, an antireflection film 24, a second passivation film 32, and the like. This will be described in more detail.

  The semiconductor substrate 160 can be composed of a crystalline semiconductor. As an example, the semiconductor substrate 160 can be formed of a single crystal or a polycrystalline semiconductor (for example, single crystal or polycrystalline silicon). In particular, the semiconductor substrate 160 may be formed of a single crystal semiconductor (for example, a single crystal semiconductor wafer, more specifically, a single crystal silicon wafer). Thus, when the semiconductor substrate 160 is made of a single crystal semiconductor (for example, single crystal silicon), the solar cell 150 is based on the semiconductor substrate 160 made of a crystalline semiconductor with few defects because of high crystallinity. It becomes like this. Accordingly, the solar cell 150 can have excellent electrical characteristics.

  The front surface and / or the back surface of the semiconductor substrate 160 may be textured to have unevenness. As an example, the unevenness may have a pyramid shape with an outer surface constituted by the (111) plane of the semiconductor substrate 160 and having an irregular size. When unevenness is formed on the front surface of the semiconductor substrate 160 by such texturing to increase the surface roughness, the reflectance of light incident from the front surface of the semiconductor substrate 160 can be reduced. Therefore, the amount of light reaching the pn junction formed by the base region 10 and the first conductivity type region 20 can be increased, and light loss can be minimized. However, the present invention is not limited to this, and unevenness due to texturing may not be formed on the front surface and the back surface of the semiconductor substrate 160.

  The semiconductor substrate 160 may include a base region 10 having a second conductivity type including a second conductivity type dopant at a relatively low doping concentration. As an example, the base region 10 may be located farther from the front surface of the semiconductor substrate 160 or closer to the back surface than the first conductivity type region 20. The base region 10 can be located closer to the front surface of the semiconductor substrate 160 or farther from the back surface than the second conductivity type region 30. However, the present invention is not limited to this, and it goes without saying that the position of the base region 10 may be changed.

  Here, the base region 10 may be made of a crystalline semiconductor containing a second conductivity type dopant. As an example, the base region 10 may be composed of a single crystal or a polycrystalline semiconductor (for example, single crystal or polycrystalline silicon) including the second conductivity type dopant. In particular, the base region 10 may be composed of a single crystal semiconductor (for example, a single crystal semiconductor wafer, more specifically, a single crystal silicon wafer) including the second conductivity type dopant.

  The second conductivity type can be n-type or p-type. When the base region 10 has an n-type, the base region 10 may be a single crystal or a polycrystal doped with phosphorus (P), arsenic (As), bismuth (Bi), antimony (Sb), etc., which are group 5 elements. It can be composed of a crystalline semiconductor. In the case where the base region 10 has p-type, the base region 10 may be a single crystal or multiple doped with a group 3 element such as boron (B), aluminum (Al), gallium (Ga), or indium (In). It can be composed of a crystalline semiconductor.

  However, the present invention is not limited to this, and the base region 10 and the second conductivity type dopant may be composed of various materials.

  As an example, the base region 10 may be n-type. In this case, the first conductivity type region 20 that forms a pn junction with the base region 10 has a p-type. When such a pn junction is irradiated with light, electrons generated by the photoelectric effect move to the back side of the semiconductor substrate 160 and are collected by the second electrode 44, and holes move to the front side of the semiconductor substrate 160. And collected by the first electrode 42. This generates electrical energy. Then, holes whose movement speed is slower than that of electrons move to the front surface instead of the back surface of the semiconductor substrate 160, thereby improving the conversion efficiency. However, the present invention is not limited to this, and the base region 10 and the second conductivity type region 30 may have a p-type, and the first conductivity type region 20 may have an n-type.

  A first conductivity type region 20 having a first conductivity type opposite to the base region 10 may be formed on the front side of the semiconductor substrate 160. The first conductivity type region 20 forms a pn junction with the base region 10 and constitutes an emitter region that generates carriers by photoelectric conversion.

  In the present embodiment, the first conductivity type region 20 may be constituted by a doping region that constitutes a part of the semiconductor substrate 160. In this case, the 1st conductivity type area | region 20 can be comprised with the crystalline semiconductor containing a 1st conductivity type dopant. As an example, the first conductivity type region 20 can be formed of a single crystal or a polycrystalline semiconductor (as an example, single crystal or polycrystalline silicon) containing the first conductivity type dopant. In particular, the first conductivity type region 20 may be composed of a single crystal semiconductor (for example, a single crystal semiconductor wafer, more specifically, a single crystal silicon wafer) containing the first conductivity type dopant. As described above, the first conductivity type region 20 constitutes a part of the semiconductor substrate 160, and the bonding characteristics between the base region 10 and the first conductivity type region 20 can be improved.

  However, the present invention is not limited to this, and the first conductivity type region 20 may be formed on the semiconductor substrate 160 separately from the semiconductor substrate 160. In this case, the first conductivity type region 20 can be formed of a semiconductor layer having a crystal structure different from that of the semiconductor substrate 160 so as to be easily formed on the semiconductor substrate 160. For example, the first conductivity type region 20 may be an amorphous semiconductor, a microcrystalline semiconductor, or a polycrystalline semiconductor (for example, amorphous silicon, microcrystalline silicon, or polycrystal that can be easily manufactured by various methods such as vapor deposition. Crystalline silicon) or the like can be formed by doping the first conductivity type dopant. Various other modifications are possible.

  The first conductivity type may have a p-type or an n-type. When the first conductivity type region 20 is p-type, the first conductivity type region 20 is doped with a group 3 element such as boron (B), aluminum (Al), gallium (Ga), indium (In), or the like. It can be composed of a single crystal or polycrystalline semiconductor. When the first conductivity type region 20 has n-type, the first conductivity type region 20 is doped with phosphorus (P), arsenic (As), bismuth (Bi), antimony (Sb), etc., which are group 5 elements. It can be composed of a single crystal or polycrystalline semiconductor. As an example, the first conductivity type region 20 may be a single crystal or a polycrystalline semiconductor doped with boron. However, the present invention is not limited to this, and various substances may be used as the first conductivity type dopant.

  In the drawing, an example in which the first conductivity type region 20 has a uniform structure having a uniform doping concentration as a whole is shown. However, the present invention is not limited to this. Therefore, as another example, as shown in FIG. 4, the first conductivity type region 20 may have a selective structure.

  Referring to FIG. 4, the first conductivity type region 20 having a selective structure includes a first portion 20a formed adjacent to the first electrode 42 and in contact with the first electrode 42, and a portion other than the first portion 20a. And a second portion 20b formed on the substrate.

  The first portion 20a may have a relatively low resistance because of a high doping concentration, and the second portion 20b may have a relatively high resistance because the doping concentration is lower than that of the first portion 20a. . And the thickness of the 1st part 20a can be made thicker than the 1st part 20a. That is, the junction depth of the first portion 20a may be larger than the junction depth of the second portion 20b.

  Thus, in the present embodiment, a shallow emitter is realized by forming the second portion 20b having a relatively high resistance in a portion other than the first electrode 42 where light is incident. Thereby, the current density of the solar cell 150 can be improved. As described above, by forming the first portion 20 a having a relatively low resistance in the portion adjacent to the first electrode 42, the contact resistance with the first electrode 42 can be reduced. This can maximize efficiency.

  Various other structures and shapes may be applied to the structure and shape of the first conductivity type region 20.

  Referring to FIG. 3 again, a second conductivity type region having the same second conductivity type as that of the base region 10 and including a second conductivity type dopant at a higher doping concentration than the base region 10 is provided on the back side of the semiconductor substrate 160. 30 may be formed. The second conductivity type region 30 forms a back surface field and prevents the loss of carriers due to recombination on the surface of the semiconductor substrate 160 (more precisely, the back surface of the semiconductor substrate 160). Configure the area.

  In the present embodiment, the second conductivity type region 30 can be constituted by a doping region that constitutes a part of the semiconductor substrate 160. In this case, the second conductivity type region 30 can be composed of a crystalline semiconductor containing the second conductivity type dopant. As an example, the second conductivity type region 30 can be composed of a single crystal or a polycrystalline semiconductor (as an example, single crystal or polycrystalline silicon) containing the second conductivity type dopant. In particular, the second conductivity type region 30 may be composed of a single crystal semiconductor (for example, a single crystal semiconductor wafer, more specifically, a single crystal silicon wafer) containing the second conductivity type dopant. As described above, the second conductivity type region 30 constitutes a part of the semiconductor substrate 160, so that the junction characteristics between the base region 10 and the second conductivity type region 30 can be improved.

  However, the present invention is not limited to this, and the second conductivity type region 30 may be formed on the semiconductor substrate 160 separately from the semiconductor substrate 160. In this case, the second conductivity type region 30 may be formed of a semiconductor layer having a crystal structure different from that of the semiconductor substrate 160 so as to be easily formed on the semiconductor substrate 160. For example, the second conductivity type region 30 may be an amorphous semiconductor, a microcrystalline semiconductor, or a polycrystalline semiconductor (for example, amorphous silicon, microcrystalline silicon, or polycrystal that can be easily manufactured by various methods such as vapor deposition. Crystalline silicon) or the like can be formed by doping the second conductivity type dopant. Various other modifications are possible.

  The second conductivity type can be n-type or p-type. When the second conductivity type region 30 has n-type, the second conductivity type region 30 is doped with phosphorus (P), arsenic (As), bismuth (Bi), antimony (Sb), etc., which are group 5 elements. It can be composed of a single crystal or polycrystalline semiconductor. When the second conductivity type region 30 has p-type, the second conductivity type region 30 is doped with a group 3 element such as boron (B), aluminum (Al), gallium (Ga), indium (In), or the like. It can be composed of a single crystal or polycrystalline semiconductor. As an example, the second conductivity type region 30 may be a single crystal or a polycrystalline semiconductor doped with phosphorus. However, the present invention is not limited to this, and various substances may be used as the second conductivity type dopant. The second conductivity type dopant in the second conductivity type region 30 may be the same material as the second conductivity type dopant in the base region 10 or may be a different material.

  In this embodiment, the second conductivity type region 30 has a uniform structure having a uniform doping concentration as a whole. However, the present invention is not limited to this. Therefore, as another example, the second conductivity type region 30 may have a selective structure. In the selective structure, a portion of the second conductivity type region 30 adjacent to the second electrode 44 has a high doping concentration, a large junction depth and a low resistance, and the other portions have a low doping concentration and a small junction depth. And can have high resistance. Since the selective structure of the second conductivity type region 30 is similar or identical to the selective structure of the first conductivity type region 20 shown in FIG. 4, the first conductivity of the selective structure described with reference to FIG. The description regarding the mold region 20 can be applied to the second conductivity type region 30. As another embodiment, as shown in FIG. 4, the second conductivity type region 30 may have a local structure.

  Referring to FIG. 4, the second conductivity type region 30 having a local structure may include a first portion 30 a that is locally formed at a portion connected to the second electrode 44. In this case, the second conductivity type region 30 is located in the portion connected to the second electrode 44, the contact resistance with the second electrode 44 is reduced, and the fill factor (FF) characteristic can be maintained high. it can. On the other hand, in the portion not connected to the second electrode 44, the second conductivity type region 30 composed of the doping region is not formed, the recombination that may occur in the doping region is reduced, and the short-circuit current (Jsc) is reduced. ) And the open circuit voltage can be improved. In addition, the portion where the second conductivity type region 30 is not formed has an excellent value of internal quantum efficiency (IQE), and thus has very excellent characteristics with respect to light having a long wavelength. Therefore, the characteristics with respect to light having a long wavelength can be greatly improved as compared with the uniform structure and the selective structure in which the doping region is entirely formed. As described above, the second conductivity type region 30 having a local structure can maintain the fill factor, the short-circuit current density, and the open-circuit voltage related to the efficiency of the solar cell 150 at a high level, and can improve the efficiency of the solar cell 150.

  In addition, various structures may be applied to the structure of the second conductivity type region 30.

  Referring to FIG. 3 again, the first passivation film 22 and the antireflection film 24 are formed on the front surface of the semiconductor substrate 160, more precisely, on the first conductivity type region 20 provided in or on the semiconductor substrate 160. Are formed in order, and the first electrode 42 penetrates the first passivation film 22 and the antireflection film 24 (that is, through the opening 102) and is electrically connected to the first conductivity type region 20 (more specifically, Contact).

  The first passivation film 22 and the antireflection film 24 are formed substantially over the entire front surface of the semiconductor substrate 160 except for the opening 102 corresponding to the first electrode 42.

  The first passivation film 22 is formed in contact with the first conductivity type region 20 and immobilizes defects present on the surface or bulk of the first conductivity type region 20. Thereby, the recombination sites of minority carriers can be removed, and the open circuit voltage (Voc) of the solar cell 150 can be increased. The antireflection film 24 reduces the reflectance of light incident on the front surface of the semiconductor substrate 160. Accordingly, the reflectance of light incident from the front surface of the semiconductor substrate 160 can be lowered, and the amount of light reaching the pn junction formed by the base region 10 and the first conductivity type region 20 can be increased. Thereby, the short circuit current (Isc) of the solar cell 150 can be increased. As described above, the first passivation film 22 and the antireflection film 24 can increase the open-circuit voltage and the short-circuit current of the solar cell 150 and improve the efficiency of the solar cell 150.

The first passivation film 22 can be formed of various materials. As an example, the passivation film 22 is any one selected from the group consisting of a silicon nitride film, a hydrogen-containing silicon nitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, MgF ₂ , ZnS, TiO _2, and CeO _2. It can have a multilayer structure in which one single film or two or more films are combined. For example, the first passivation film 22 may include a silicon oxide film, a silicon nitride film, or the like having a fixed positive charge when the first conductivity type region 20 has an n-type. When p has a p-type, an aluminum oxide film having a fixed negative charge can be included.

The radiation prevention film 24 can be formed of various materials. As an example, the antireflection film 24 is any one selected from the group consisting of a silicon nitride film, a hydrogen-containing silicon nitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, MgF ₂ , ZnS, TiO _2, and CeO ₂ . One single film or a multilayer film structure in which two or more films are combined can be used. As an example, the antireflection film 24 may include silicon nitride.

  However, the present invention is not limited to this, and it goes without saying that the first passivation film 22 and the antireflection film 24 may contain various substances. In addition, one of the first passivation film 22 and the antireflection film 24 serves as an antireflection function and a passivation function, and the other may not be provided. Alternatively, various films other than the first passivation film 22 and the antireflection film 24 may be formed on the semiconductor substrate 160. Various other modifications are possible.

  The first electrode 42 is electrically connected to the first conductivity type region 20 through the opening 102 formed in the first passivation film 22 and the antireflection film 24 (that is, through the first passivation film 22 and the antireflection film 24). Connected. Such a first electrode 42 can be made of a material having excellent electrical conductivity (for example, metal). Although the 1st electrode 42 may have a specific pattern so that light can permeate | transmit, the specific shape is later mentioned with reference to FIG.

  A second passivation film 32 is formed on the back surface of the semiconductor substrate 160, more precisely, on the second conductivity type region 30 formed on the semiconductor substrate 160, and the second electrode 44 penetrates the second passivation film 32. (Ie, through the opening 104) to be electrically connected (as an example to the second conductivity type region 30).

  The second passivation film 32 is formed on the entire back surface of the semiconductor substrate 160 except for the opening 104 corresponding to the second electrode 44.

  The second passivation film 32 is formed in contact with the second conductivity type region 30 and immobilizes defects present on the surface or bulk of the second conductivity type region 30. As a result, the recombination sites of minority carriers can be removed, and the open circuit voltage (Voc) of the solar cell 150 can be increased.

The second passivation film 32 can be formed of various materials. As an example, the second passivation film 32 is any selected from the group consisting of a silicon nitride film, a hydrogen-containing silicon nitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, MgF ₂ , ZnS, TiO _2, and CeO _2. A single film or a multilayer structure in which two or more films are combined can be used. For example, the second passivation film 32 may include a silicon oxide film, a silicon nitride film, or the like having a fixed positive charge when the second conductivity type region 30 has an n-type. When p has a p-type, an aluminum oxide film having a fixed negative charge can be included.

  However, the present invention is not limited to this, and it goes without saying that the second passivation film 32 may contain various substances. Alternatively, various films other than the second passivation film 32 may be formed on the back surface of the semiconductor substrate 160. Various other modifications are possible.

  The second electrode 44 is electrically connected to the second conductivity type region 30 through the opening 104 formed in the second passivation film 32. Such a second electrode 44 can be made of a material having excellent electrical conductivity (for example, metal). Although the 2nd electrode 44 may have a specific pattern so that light can permeate | transmit, the specific shape is mentioned later.

  Thus, in this embodiment, since the first and second electrodes 42 and 44 of the solar cell 150 have a certain pattern, the solar cell 150 receives light from both sides where light can enter from the front surface and the back surface of the semiconductor substrate 160. It has a bi-facial structure. As a result, the amount of light used in the solar cell 150 can be increased, which can contribute to improving the efficiency of the solar cell 150.

  However, the present invention is not limited to this, and it is possible to have a structure in which the second electrode 44 is formed entirely on the back side of the semiconductor substrate 160. In addition, the first and second conductivity type regions 20 and 30 and the first and second electrodes 42 and 44 may be located on one surface (for example, the back surface side) of the semiconductor substrate 160. In addition, at least one of the second conductivity type regions 20 and 30 may be provided on both surfaces of the semiconductor substrate 160. That is, the above-described solar cell 150 is merely provided as an example, and the present invention is not limited to this.

  The solar cell 150 described above is electrically connected to the adjacent solar cell 150 by the wiring member 142, which will be described in more detail with reference to FIG. 5 together with FIGS. 1 and 2.

  FIG. 5 is a perspective view schematically showing the first solar cell 151 and the second solar cell 152 connected by the wiring member 142 in the solar cell panel 100 of FIG. In FIG. 5, the solar cell 150 is simply shown around the semiconductor substrate 160 and the electrodes 42 and 44. 6 is a perspective view and a cross-sectional view showing the wiring member 142 before being attached to the electrodes 42 and 44 of the solar cell 150 shown in FIG. 1, and FIG. 7 is a solar cell 150 shown in FIG. It is sectional drawing which shows the wiring material 142 adhering to the pad part (reference number 422 of FIG. 9) of the electrodes 42 and 44 of FIG. FIG. 8 is a schematic cross-sectional view of a portion A in FIG. For simplicity of illustration and explanation, only the pad portion 422 and the wiring member 142 are shown in FIG. In FIG. 8, the wiring member 142 that connects the first solar cell 151 and the second solar cell 152 is mainly illustrated.

  Referring to FIG. 5, two adjacent solar cells 150 (for example, a first solar cell 151 and a second solar cell 152) among a plurality of solar cells 150 are connected by a wiring member 142. At this time, the wiring member 142 is the first electrode 42 provided on the front surface of the first solar cell 151 and the second solar cell located on one side (the lower left side in the drawing) of the first solar cell 151. The second electrode 44 provided on the back surface of 152 is connected. Then, the other wiring member 1420a includes the second electrode 44 provided on the back surface of the first solar cell 151, and other solar cells located on the other side (upper right side in the drawing) of the first solar cell 151. The first electrode 42 provided on the front surface is connected. In addition, another wiring member 1420b is disposed on the first electrode 42 provided on the front surface of the second solar cell 152, and still another solar cell located on one side (the lower left side in the drawing) of the second solar cell 152. The second electrode 44 provided on the back surface of the second electrode 44 is connected. Thus, the plurality of solar cells 150 can be connected in a row by the wiring members 142, 1420a, and 1420b. Hereinafter, the description relating to the wiring member 142 can be applied to any wiring member 142 that connects two adjacent solar cells 150.

  In this embodiment, the wiring member 142 is connected from the first edge 161 in a state where it is connected to the first electrode 42 (more specifically, the bus bar line 42b of the first electrode 42) on the front surface of the first solar cell 151. The first portion 1421 extending toward the opposite second edge 162 and the back surface of the second solar cell 152 are connected to the second electrode 44 (more specifically, the bus bar line 44b of the second electrode 44). A second portion 1422 extending from the first edge 161 toward the second edge 162 opposite thereto, and extending from the front surface of the second edge 162 of the first solar cell 151 to the rear surface of the second solar cell 152. The third portion 1423 connecting the first portion 1421 and the second portion 1422 may be included. Accordingly, the wiring member 142 can be positioned across the second solar cell 152 in a partial region of the second solar cell 152 after crossing the first solar cell 151 in a partial region of the first solar cell 151. Thus, the wiring member 142 has a smaller width than the first and second solar cells 151 and 152, and corresponds to a part of the first and second solar cells 151 and 152 (for example, the bus bar electrode 42b). Since it is formed only in a portion, the first and second solar cells 151 and 152 can be effectively connected even with a small area.

  As an example, the wiring member 142 may be disposed so as to extend along the bus bar line 42b while being in contact with the bus bar line 42b on the bus bar line 42b in the first and second electrodes 42 and 44. As a result, the wiring member 142 and the first and second electrodes 42 and 44 are continuously in contact with each other, and the electrical connection characteristics can be improved. However, the present invention is not limited to this. The bus bar line 42b may not be provided. In this case, the wiring member 142 may be in contact with and connected to the plurality of finger lines 42a across the plurality of finger lines 42a in a direction intersecting the finger lines 42a. It may be arranged. However, the present invention is not limited to this.

  If one surface of each solar cell 150 is used as a reference, a plurality of wiring members 142 are provided, and the electrical connection characteristics of the adjacent solar cells 150 can be improved. In particular, in the present embodiment, the wiring member 142 is formed of a wire having a smaller width than a ribbon having a relatively wide width (for example, 1 mm to 2 mm) that has been used, and one surface of each solar cell 150 is used as a reference. In addition, a larger number of wiring members 142 than the number of existing ribbons (for example, 2 to 5) are used.

  In this embodiment, as shown in FIG. 6, the wiring member 142 includes a core layer 142a, and can include a coating layer 142b coated on the surface of the core layer 142a with a small thickness. The core layer 142a is made of a wire having excellent electrical conductivity and substantially transmits current, and the coating layer 142b protects the core layer 142a, improves the adhesion characteristics of the wiring material 142, and the like. Can play various roles. As an example, the coating layer 142b includes a solder material and can be melted by heat to easily attach the wiring member 142 to the electrodes 42 and 44. Accordingly, the wiring material 142 can be easily attached to the electrodes 42 and 44 by soldering only by applying heat after the wiring material 142 is disposed on the electrodes 42 and 44 without using a separate adhesive or the like. be able to. As a result, the tabbing process can be simplified.

  At this time, the tabbing process can be performed by applying a flux to the wiring member 142 and applying heat after the wiring member 142 coated with the flux is disposed on the electrodes 42 and 44. The flux is for preventing the formation of an oxide film that hinders soldering, and is not necessarily used.

  The core layer 142a is made of a material (for example, metal, more specifically, Ni, Cu, Ag, Al) that can have excellent electrical conductivity as a main material (for example, a material containing 50 wt% or more, more specifically, Specifically, it can be included as a substance that is 90 wt% or more. When the coating layer 142b includes a solder material, the coating layer 142b may include a material such as Pb, Sn, SnIn, SnBi, SnPb, SnPbAg, SnCuAg, or SnCU as a main material. However, the present invention is not limited to this, and the core layer 142a and the coating layer 142b may include various substances.

  As another example, the wiring member 142 may be attached to the electrodes 42 and 44 using another conductive adhesive. In this case, the wiring member 142 may or may not have the coating layer 142b. As the conductive adhesive, conductive particles such as Ni, Al, Ag, Cu, Pb, Sn, SnIn, SnBi, SnP, SnPbAg, SnCuAg, SnCu, and the like are used as epoxy synthetic resin or silicon synthetic resin. It is possible to use a substance that exists in the form of a liquid phase and that is thermoset when heated. When such a conductive adhesive is used, heat is applied after the conductive adhesive is disposed on the electrodes 42 and 44 and the wiring member 142 is disposed thereon, or the surface of the wiring member 142 is used. After the conductive adhesive is applied or disposed on the wiring member 142, the wiring material 142 can be attached to the electrodes 42 and 44 by placing the conductive adhesive on the electrodes 42 and 44 and applying heat.

  Thus, by using a wire having a smaller width than the existing ribbon as the wiring member 142, the material cost can be greatly reduced. Further, since the wiring member 142 has a smaller width than the ribbon, the output of the solar cell and the panel 100 can be improved by providing a sufficient number of wiring members 142 and minimizing the movement distance of the carrier. .

  In addition, the wire constituting the wiring member 142 according to the present embodiment has a circular or elliptical cross section, a curved cross section, or a round cross-section, and can induce reflection or irregular reflection. Thereby, the light reflected by the round surface of the wire constituting the wiring member 142 is reflected or totally reflected by the front substrate 110 or the back substrate 200 provided on the front surface or the back surface of the solar cell 150, and the solar cell 150. It can be made to re-enter on. Thereby, the output of the solar cell panel 100 can be improved effectively. However, the present invention is not limited to this. Therefore, the wire constituting the wiring member 142 may have a polygonal shape such as a quadrangle, and may have other various shapes.

  In the present embodiment, the wiring member 142 may have a width W1 of 250 μm to 500 μm. The current generated in the solar cell 150 is efficiently transmitted to an external circuit (for example, a bypass diode of a bus ribbon or a junction box) or another solar cell 150 by the wire-shaped wiring member 142 having such a width. Can do. In this embodiment, the wiring member 142 is positioned and fixed on the electrodes 42 and 44 of the solar cell 150 without being inserted into a separate layer or film. For this reason, if the width W1 of the wiring member 142 is less than 250 μm, the strength of the wiring member 142 may be insufficient, and the connection area of the electrodes 42 and 44 is very small. And the adhesion can be low. When the width W1 of the wiring material 142 exceeds 500 μm, the material cost of the wiring material 142 increases, the wiring material 142 obstructs the incidence of light incident on the front surface of the solar cell 150, and the light loss increases. sell. Further, since the force applied to the wiring member 142 in the direction away from the electrodes 42 and 44 is increased, the adhesion force between the wiring member 142 and the electrodes 42 and 44 is low, and there is a problem such as a crack in the electrodes 42 and 44 or the semiconductor substrate 160. Can occur. As an example, the width W1 of the wiring member 142 may be 350 μm to 450 μm (particularly 350 μm to 400 μm). By setting it within this range, the output can be improved while increasing the adhesive force with the electrodes 42 and 44.

  Here, before the tabbing process, the thickness T2 of the coating layer 142b in the wiring member 142 is as small as 10% or less (for example, 20 μm or less, for example, 7 μm to 20 μm) of the width of the core layer 142a. At this time, if the thickness of the coating layer 142b is less than 7 μm, the tabbing process may not be smoothly performed. On the other hand, when the thickness of the coating layer 142b exceeds 20 μm, the material cost increases, the width of the core layer 142a decreases, and the strength of the wiring member 142 may decrease. Then, after the wiring member 142 is attached to the solar cell 150 by the tabbing process, as shown in FIG. 7, the coating layer 142b melts and flows between the wiring member 142 and the solar cell 150 (more precisely, It is thickly formed between the wiring member 142 and the pad portions 422 of the electrodes 42 and 44, and relatively thin on the other surface of the core layer 142a. The portion formed between the wiring member 142 and the solar cell 150 can have a width W7 that is the same as or larger than the diameter of the core layer 142a of the wiring member 142. The coating layer 142b may have a thickness T1 of 11 μm to 21 μm between the wiring member 142 and the pad portion 422 of the electrodes 42 and 44, and the coating layer 142b may be 2 μm or less on the surface of the other part of the core layer 142a. As an example, it can have a very thin thickness T2 of 0.5 μm to 1.5 μm. In consideration of this, the width W1 of the wiring member 142 in this specification means the width or diameter of the core layer 142a in a plane that passes through the center of the wiring member 142 and is perpendicular to the thickness direction of the solar cell 150. be able to. At this time, since the coating layer 142b has a very thin thickness in the portion located at the center of the core layer 142a, the coating layer 142b hardly affects the width of the wiring member 142, and the width W1 of the wiring member 142 is It may mean the sum or diameter of the widths of the core layer 142a and the coating layer 142b in a plane passing through the center of the core layer 142a and perpendicular to the thickness direction of the solar cell 150.

  Thus, if the wiring material 142 of a wire form is provided, there can exist an effect of an output improvement. However, in this embodiment, since the adjacent solar cells 150 are electrically connected using the wiring member 142 having a thinner width than in the conventional case, the adhesion area between the wiring member 142 and the electrodes 42 and 44 is small. , Adhesion may be insufficient. In addition, when the wiring member 142 has a circular, elliptical, or round cross section, the adhesion area with the electrodes 42 and 44 is further reduced, so that the adhesion force with the electrodes 42 and 44 may be insufficient. Further, when the wiring member 142 has a circular, elliptical, or rounded cross section, the thickness of the wiring member 142 is relatively increased, and the solar cell 150 or the semiconductor substrate 160 is more easily bent.

  In particular, between the first solar cell 151 and the second solar cell 152, the wiring member 142 must be connected from the front surface of the first solar cell 151 to the back surface of the second solar cell 152. The wiring member 142 can be bent. That is, as shown in FIG. 8, the first portion 1421 of the wiring member 142 maintains a state of being attached (contacted as an example) to the first electrode 42 of the first solar cell 151, and the wiring member 142. The second portion 1422 maintains a state of being attached (contacted as an example) to the second electrode 44 of the second solar cell 152. The third portion 1423 of the wiring member 142 must be connected so as not to bend the first portion 1421 and the second portion 1422 described above. For this reason, the third portion 1423 includes a portion 1423a that is bent so as to have an arc shape that bulges to the front side so as to have a certain distance from the first solar cell 151 in the vicinity of the edge of the first solar cell 151, and the above-described portion 1423a. And a portion 1423b that is connected so as to have an inflection point and bends so as to have an arc shape that swells to the back side so as to have a certain distance from the second solar cell 152 in the vicinity of the edge of the second solar cell 152. be able to.

  In this way, the bent portions 1423a and 1423b of the third portion 1423 are the connection portions with the first portion 1421 or the second portion 1422 (that is, the edge portion of the first solar cell 151 or the edge portion of the second solar cell 152). It has the part which goes to the direction which goes away from the 1st or 2nd solar cell 151,152 gradually. As a result, the wiring member 142 receives a force in the direction away from the electrodes 42 and 44 at the edge portion of the solar cell 150.

  The boundary between the first portion 1421 and the third portion 1423 or the boundary between the second portion 1422 and the third portion 1423 (that is, the last connection portion between the wiring member 142 and the electrodes 42 and 44) is at the edge of the solar cell 150. The closer to the arc, the smaller the radius of curvature of the arc. For this reason, the force which the wiring material 142 close to the edge of the solar cell 150 receives in the direction away from the solar cell 150 is increased, and the adhesion force between the wiring material 142 and the electrodes 42 and 44 can be reduced. Therefore, when the wire-shaped wiring member 142 is provided as in this embodiment, the portions of the electrodes 42 and 44 that are adjacent to the edge of the solar cell 150 and to which the wiring member 142 is connected (particularly, the wiring member 142 is connected). The wiring member 142 and the electrode can be bonded to each other with a sufficient bonding force or adhesive force by separating the pad portion 422) having a large area and a large bonding force from the edge of the solar cell 150 by a certain distance or more. 42, 44 can be attached.

  In consideration of this, the electrodes 42 and 44 of the solar cell 150 are formed in this embodiment, which will be described in detail with reference to FIG. In the following, the second electrode 44 will be described after detailed description with reference to the first electrode 42 with reference to FIG. 9.

  FIG. 9 is a plan view showing a solar cell included in the solar cell panel of FIG. 1 and a ribbon connected thereto.

  Referring to FIG. 9, in this embodiment, the solar cell 150 (or the semiconductor substrate 160) is partitioned into an electrode area EA and an edge area PA. At this time, the solar cell 150 (or the semiconductor substrate 160), for example, intersects the first and second edges 161, 162 parallel to the finger line 42a and the finger line 42a (for example, intersects perpendicularly or obliquely). It may have third and fourth edges 163,164. The third and fourth edges 163 and 164 are substantially perpendicular to the first and second edges 161 and 162, respectively, and a central portion 163a and 164a occupying most of the third or fourth edges 163 and 164, and a center Inclined portions 163b and 163b that are inclined from the portions 163a and 164a and connected to the first and second edges 161 and 162, respectively. Thereby, for example, when viewed from the plane, the solar cell 150 can have a substantially octagonal shape. However, the present invention is not limited to this, and the planar shape of the solar cell 150 can have various shapes.

  In the present embodiment, the electrode area EA may be an area where finger lines 42a formed in parallel to each other are arranged at a uniform pitch P. The electrode area EA can include a plurality of electrode areas EA partitioned by the wiring material 142. The edge area PA includes a space between two adjacent electrode areas EA, and the edge of the semiconductor substrate 160 or the solar cell 150 (that is, the edge or the wiring material 142 positioned in the length direction of the wiring material 142 or the bus bar line 42b). Or the area | region located adjacent to the bus-bar line 42b (edge which crosses as an example) may be sufficient. At this time, the edge region PA may be a region where the electrode portions 424a and 424b are located at a density lower than the density of the finger lines 42a in the electrode region EA, or may be a region where the electrode portions 424a and 424b are not located. Good.

  In this embodiment, the electrode area EA may include a plurality of electrode areas EA that are partitioned based on the bus bar line 42b or the wiring member 142. More specifically, the electrode area EA includes the first electrode area EA1 provided between two adjacent bus bar lines 42b or the wiring material 142, and the third and fourth edges 163 of the wiring material 142 and the solar cell 150. , 164 and two second electrode regions EA2 respectively provided between them. In the present embodiment, a plurality of wiring members 142 are provided on the basis of one surface of the solar cell 150 (for example, six or more), and therefore a plurality of first electrode regions EA1 (that is, one more than the number of wiring members 142). A small number).

  At this time, the width W2 of the first electrode area EA1 may be smaller than the width W3 of the second electrode area EA2. In this embodiment, a plurality of wiring members 142 or bus bar lines 42b are provided. Therefore, by relatively increasing the width W3 of the second electrode area EA2, the inclined portions 163b and 164b of the third or fourth edge 163 and 164 can be positioned in the second electrode area EA2, and this Thus, the bus bar line 42b or the wiring member 142 can be prevented from being located at the third or fourth edge 163,164. However, the present invention is not limited to this, and the width W2 of the first electrode area EA1 and the width W3 of the second electrode area EA may have various values.

  The edge region PA corresponds to a portion where the wiring member 142 is located, and is a portion other than the first edge region PA1 located between the finger electrodes 42a and the first edge region PA1, and the outermost finger electrode 42a. And a second edge region PA2 spaced apart from the first to fourth edges 161, 162, 163, and 164 of the semiconductor substrate 160 by a certain distance. The first edge region PA1 can be located in a portion adjacent to the edge of the solar cell 150 in the portion where the wiring member 142 is located. The first edge region PA <b> 1 is a region formed to separate the first pad portion 422 a from the edge of the solar cell 150 so that the wiring member 142 can be attached to the first electrode 42 with a sufficient bonding force.

  At this time, the edge region PA includes one end edge region PA3 located at one end portion of the bus bar line 42b adjacent to the first edge 161 of the semiconductor substrate 160 between the two adjacent electrode regions EA, and the first region of the semiconductor substrate 160. The other end edge region PA4 located at the other end of the bus bar line 42b adjacent to the two edges 162 may be included. More specifically, the one-end edge area PA3 is a part of the second edge area PA2 corresponding to each of the first edge areas PA1 adjacent to the first edge 161 (that is, in the second edge area PA2). 1 edge region PA and the part located between the 1st edge 161) can be included. The other end edge area PA4 is a part of the second edge area PA2 corresponding to the first edge area PA1 adjacent to the second edge 162 (that is, the first edge area PA2 in the second edge area PA2). A portion located between the PA and the second edge 162).

  Here, the one end edge region PA3 may be a region that is located adjacent to the first edge 161 of the semiconductor substrate 160 and in which the end of the wiring member 142 is located. The wiring member 142 may be extended to another solar cell 150 or an external circuit through the other end edge region PA4 and the second edge 162 of the semiconductor substrate 160. In the specification, terms such as “one end” and “the other end” are merely for distinction, and the present invention is not limited thereto.

  The first electrode 42 may include a plurality of finger lines 42a each having a constant width W5 and a pitch P in the electrode area EA and provided apart from each other. The drawing shows an example in which the finger lines 42a are provided side by side in the first direction and are parallel to the main edges (particularly, the first and second edges 161 and 162) of the solar cell 150. The invention is not limited to this. At this time, the plurality of finger lines 42a may include outermost finger lines 421a and 422a that are positioned closest to the edges (more specifically, the first and second edges 161 and 162) of the semiconductor substrate 160. it can.

  As an example, the finger line 42a of the first electrode 42 may have a width W5 of 35 μm to 120 μm. Also, the finger lines 42a of the first electrode 42 may have a pitch P of 1.2 mm to 2.8 mm. Further, the number of finger lines 42a may be 55 to 130 in the direction intersecting the finger lines 42a. The width W5 and the pitch P can be formed under a gentle process condition, and can effectively collect the current generated by the photoelectric conversion, while minimizing the light loss due to the finger line 42a. As such, it is limited. The thickness of the finger line 42a may be 5 μm to 50 μm. The thickness of such a finger line 42a can be easily formed during the process, and is in a range that can have a desired specific resistance. However, the present invention is not limited to this, and the width, pitch, thickness, and the like of the finger line 42a are variously changed according to changes in process conditions, the size of the solar cell 150, the constituent material of the finger line 42a, and the like. May be.

  At this time, the width W1 of the wiring member 142 may be smaller than the pitch P of the finger lines 42a and larger than the width of the finger lines 42a. However, the present invention is not limited to this, and various modifications are possible.

  The first electrode 42 may include a bus bar line 42b that is provided in a second direction that intersects the finger line 42a at least in the electrode region EA and connects the finger line 42a. In this embodiment, the bus bar line 42b further includes electrode portions 424a and 424b located in the first edge region PA1 and positioned so as to overlap the wiring member 142.

  As an example, the bus bar line 42b may be continuously provided from a portion adjacent to the first edge 161 to a portion adjacent to the second edge 162 in the electrode area EA. As described above, the bus bar line 42b can be positioned so as to correspond to a portion where the wiring member 142 for connection to the adjacent solar cell 150 is positioned. Such bus bar lines 42b may be provided so as to correspond to the wiring members 142 on a one-to-one basis. Accordingly, the bus bar lines 42b may be provided in the same number as the wiring members 142 based on one surface of the solar cell 150 in the present embodiment. The bus bar line 42b referred to in the present embodiment is located in a portion adjacent to the wiring member 142, and is provided in a direction orthogonal to or inclined with respect to the finger line 42a, and is connected to, contacts with, or overlaps with the wiring member 142. Can mean.

  The bus bar line 42b has a line portion 421 that extends long with a relatively narrow width along the direction in which the wiring member 142 is connected in the electrode area EA, and a width wider than the line portion 421. A pad portion 422 that increases a connection area. The narrow width line portion 421 can minimize the area that blocks light incident on the solar cell 150, and the wide width pad portion 422 improves the adhesion between the wiring member 142 and the bus bar line 42b, Contact resistance can be reduced. The pad portion 422 has a wider width than the line portion 421 and is a region where the wiring material 142 is substantially attached. The wiring member 142 may be attached to the line portion 421, or the wiring member 142 may not be attached to the line portion 421 but may be placed.

  The pad portion 422 is located at an end portion of the line portion 421 in the electrode area EA (that is, a portion where the first electrode 42 and the wiring portion 142 are connected, or an inner end portion of one end or the other end edge regions PA3, PA4). The first pad part 422a and the second pad part 422b located in the internal region of the bus bar line 42b other than the first pad part 422a may be included. As described above, at the end of the line part 421 or the first pad part 422a, a force can be applied to the wiring member 142 in a direction away from the first electrode 42 (a direction away from the semiconductor substrate 160). For this reason, the area of the 1st pad part 422a may be larger than the 2nd pad part 422a in the said area | region, and you may make it the wiring material 142 and the 1st electrode 42 adhere with a strong adhesive force. At this time, even if the width of the first pad portion 422a is larger than the width of the second pad portion 422b, it does not greatly contribute to improving the adhesion to the wiring member 142, and therefore the first pad portion 422a The length (the length L1 in the length direction of the wiring member 142) may be larger than the length of the second pad portion 422b (the length L2 in the length direction of the wiring member 142).

  The width of the pad portion 422 (more specifically, the width of each of the first pad portion 422a and the second pad portion 422b) is that of the line portion 421, the edge portion 423, the electrode portions 424a and 424b, and the finger line 42a. May be larger. The pitch of the bus bar lines 42b may be larger than the pitch of the finger lines 42a.

  In this embodiment, an example in which the line portion 421 of the bus bar line 42b is provided so as to correspond to the wiring member 142 is shown. More specifically, conventionally, a bus bar electrode having a very large width compared to the finger line 42a is provided corresponding to the wiring member 142, but in this embodiment, it is very small compared to the bus bar electrode. A line portion 421 of the bus bar line 42b having a width is provided. In the present embodiment, the line unit 421 can connect a plurality of finger lines 42a and provide a path that can bypass the carrier when some of the finger lines 42a are disconnected.

  The bus bar electrode referred to in this specification refers to an electrode portion that is provided in a direction intersecting the finger line so as to correspond to the ribbon and has a width of 12 times or more (usually 15 times) or more of the width of the finger line. Since the bus bar electrodes have a relatively large width, two to three are usually provided. And the line part 421 of the bus-bar line 42b said by the present Example is provided in the direction which cross | intersects the finger line 42a so as to correspond to the wiring material 142, and has the width | variety 10 times or less of the width of the finger line 42a. Can be pointed out.

  As an example, the width W4 of the line portion 421 can be 0.5 to 10 times the width W5 of the finger line 42a. If this ratio is less than 0.5 times, the width of the line portion 421 becomes small, and the effect of the line portion 421 cannot be sufficiently obtained. When the ratio exceeds 10 times, the width of the line portion 421 is increased and the optical loss can be increased. In particular, since a large number of wiring members 142 are provided in this embodiment, a large number of line portions 421 must also be provided, and the optical loss can be further increased. More specifically, the width W4 of the line part 421 may be 0.5 to 7 times the width W5 of the finger line 42a. Thus, the optical loss can be further reduced by setting the ratio to 7 times or less. For example, referring to optical loss, the width W4 of the line part 421 may be 0.5 to 4 times the width W5 of the finger line 42a. More specifically, the width W4 of the line part 421 may be 0.5 to 2 times the width W5 of the finger line 42a. By setting this range, the efficiency of the solar cell 150 can be greatly improved.

  Alternatively, the width W4 of the line part 42b may be equal to or smaller than the width W1 of the wiring member 142. When the wiring member 142 has a circular, elliptical, or round cross-sectional shape, the width or area that contacts the line portion 42b is not large at the lower portion of the wiring member 142, and as a result, the width W4 of the line portion 42b is set to the width W1 of the wiring member 142. This is because it can be made equal to or smaller. Thus, if the width W4 of the line part 42b is relatively reduced, the area of the first electrode 42 can be reduced, and the material cost of the first electrode 42 can be reduced.

  As an example, the ratio of the width W1 of the wiring member 142 to the width W4 of the line portion 42b can be set to 1: 0.07 to 1: 1. If this ratio is less than 1: 0.07, the width of the line portion 42b is too small, and the electrical characteristics and the like may be deteriorated. If the ratio exceeds 1: 1, the contact characteristics with the line part 42b and the like are not greatly improved, but the area of the first electrode 42 increases, leading to problems such as an increase in light loss and an increase in material cost. As an example, if light loss, material cost, etc. are further considered, the ratio is 1: 0.1 to 1: 0.5, more specifically 1: 0.1 to 1: 0.3. May be.

  Alternatively, the width W4 of the line portion 421 may be 35 μm to 350 μm. If the width W4 of the line part 421 is less than 35 μm, the width of the line part 42b is too small, and the electrical characteristics and the like may be deteriorated. If the width W4 of the line part 421 exceeds 350 μm, the contact characteristics with the line part 42b do not greatly improve, but the area of the first electrode 42 increases, resulting in problems such as an increase in optical loss and an increase in material cost. Connected. As an example, in consideration of light loss, material cost, and the like, the width W4 of the line portion 421 may be 35 μm to 200 μm, more specifically 35 μm to 120 μm. At this time, if the electric characteristics are further considered, the width W4 of the line portion 421 that connects the pad portion 422 and the pad portion 422 may be 75 μm to 120 μm.

  However, the present invention is not limited to this. Accordingly, the width W4 of the line portion 421 can be variously modified within a range in which the optical loss is minimized while the current generated by the photoelectric conversion is effectively transmitted.

  Further, the width W6 of the pad portion 422 is larger than the width W4 of the line portion 421, and may be equal to or larger than the width W1 of the wiring member 142. The pad portion 422 is a portion for increasing the contact area with the wiring member 142 and improving the adhesion with the wiring member 142, has a width larger than that of the line portion 421, and is equal to or larger than the wiring member 142. It has a width.

  As an example, the ratio of the width W1 of the wiring member 142 to the width W6 of the pad portion 422 can be 1: 1 to 1: 5. If this ratio is less than 1: 1, the width W6 of the pad portion 422 may not be sufficient, and the adhesive force between the pad portion 422 and the wiring member 142 may be insufficient. When the ratio exceeds 1: 5, the area where light is lost by the pad portion 422 increases, and the light loss may increase. The ratio may be 1: 2 to 1: 4 (more specifically 1: 2.5 to 1: 4) in consideration of adhesion force, light loss, and the like.

  Alternatively, as an example, the width W6 of the pad portion 422 may be 0.25 mm to 2.5 mm. If the width W6 of the pad portion 422 is less than 0.25 mm, the contact area with the wiring member 142 is not sufficient, and the adhesive force between the pad portion 422 and the wiring member 142 may be insufficient. If the width W6 of the pad portion 422 exceeds 2.5 mm, the area where light is lost by the pad portion 422 increases, and the light loss may increase. As an example, the width W6 of the pad portion 422 may be 0.8 mm to 1.5 mm.

  For example, the lengths L1 and L2 of the pad portion 422 may be 0.2 mm to 30 mm. If the lengths L1 and L2 of the pad part 422 are less than 0.2 mm, the contact area with the wiring member 142 is not sufficient, and the adhesive force between the pad part 422 and the wiring member 142 may be insufficient. If the length of the pad part 422 exceeds 30 mm, the area where light is lost by the pad part 422 increases, and the light loss may increase.

  At this time, the length L1 of the first pad portion 422a to which a relatively large force is applied may be larger than the length L2 of the second pad portion 422b. More specifically, the length L1 of the first pad portion 422a may be 0.4 mm to 30 mm, and the length L1 of the first pad portion 422a is 0.4 mm to 5 mm in consideration of optical loss. It may be. The length L2 of the second pad portion 422b may be 0.02 mm to 1 mm, and more specifically 0.3 mm to 1 mm. As a result, the adhesion of the first pad portion 422a to which a large force is applied can be further improved, and the area of the second pad portion 422b can be reduced to reduce light loss, material cost, and the like.

  As an example, the pad portion 422 may have a width of 0.5 mm to 2.0 mm and may have a length of 0.2 mm to 5 mm. At this time, as described above, in order to make the area of the first pad portion 422a larger than that of the first pad portion 422b, the widths of the first pad portion 422a and the second pad portion 422b are made the same or similar to each other (as an example) The length of the first pad portion 422a can be made longer than the length of the second pad portion 422b. Accordingly, the first pad portion 422a has a length equal to or larger than the width (for example, the length is larger than the width), and the second pad portion 422b has a width equal to or larger than the length (an example). The width may be greater than the length). As an example, the first pad part 422a may have a width of 1.0 mm to 1.5 mm and a length of 3.5 mm to 4.5 mm, and the second pad part 422b may have a width of 1.0 mm to 4.5 mm. It may be 1.5 mm and the length may be 0.3 mm to 0.5 mm. By setting it as such a range, the effect by the 1st and 2nd pad parts 422a and 422b can be maximized.

  Alternatively, as an example, the ratio of the width W5 of the finger line 42a to the lengths L1 and L2 of the pad portion 422 may be 1: 1.1 to 1:20. Within such a range, the adhesion area between the pad portion 422 and the wiring member 142 can be increased, and the adhesion force between the pad portion 422a and the wiring member 142 can be improved.

  Alternatively, as an example, the ratio of the width W1 of the wiring member 142 to the lengths L1 and L2 of the pad portion 422 may be 1: 1 to 1:10. If this ratio is less than 1: 1, the lengths L1 and L2 of the pad portion 422 are not sufficient, and the adhesive force between the pad portion 422 and the wiring member 142 may be insufficient. When the ratio exceeds 1:10, the area where light is lost by the pad portion 422 increases, and the light loss may increase. The ratio may be 1: 3 to 1: 6 in consideration of adhesion force, light loss, and the like.

  Six to twenty-four (for example, twelve to twenty-two) pad portions 422 can be arranged in one bus bar line 42b. The plurality of pad portions 422 may be arranged at equal intervals. For example, the pad portion 422 can be arranged for every two to ten finger lines 42a. According to this, the part which the adhesion area of the bus-bar line 42b and the wiring material 142 increases regularly is provided, and the adhesive force of the bus-bar line 42b and the wiring material 142 can be improved. Alternatively, a plurality of pad portions 422 may be arranged with the distance between the two pad portions 422 being different. In particular, the pad portions 422 can be arranged at a high density in the end portion of the bus bar line 42b where a larger force is applied than in other portions (that is, the central portion of the bus bar line 42b). Various other modifications are possible.

  Referring again to FIG. 7, the width W <b> 1 of the wiring material 142 is a coating layer 142 b (a separate adhesive layer (for example, a soldering layer) for attaching the wiring material 142 and the pad portion 422) at a portion adjacent to the pad portion 422. , The ratio of the width W7 of the adhesive layer positioned between the pad portion 422 may be 1: 1 to 1: 3.33. However, the present invention is not limited to this, and the ratio may have various values.

  Further, the width W6 of the pad portion 422 may be equal to or larger than the width W7 of the coating layer 142b in a portion adjacent to the pad portion 422. As an example, the ratio of the width W7 of the coating layer 142b to the width W6 of the pad portion 422 in a portion adjacent to the pad portion 422 may be 1: 1 to 1: 4.5. If this ratio is less than 1: 1, the adhesive property between the wiring member 142 and the pad portion 422 may be insufficient. When the ratio exceeds 1: 4.5, the area of the pad portion 422 increases, which may lead to an increase in optical loss and an increase in manufacturing cost.

  However, the present invention is not limited to this. The width W6 and the lengths L1 and L2 of the pad portion 422 may have various values within a range in which the contact area with the wiring member 142 can be increased and the adhesion with the wiring member 142 can be improved. Further, the pad portion 422 may not be provided separately.

  Referring to FIG. 9 again, the first electrode 42 may further include an edge 423 that partitions the electrode area EA and the first edge area PA1. The edge portion 423 extends from the end portion (or the pad portion 422) of the line portion 421 and passes through the end portions of the plurality of finger lines 42a adjacent to the one end edge region PA3 to the end portions of the outermost finger lines 421a and 422a. Can be reached. The edge part 423 can connect the edge part of the finger line 42a adjacent to the edge area | region PA3 at one end. When the edge portion 423 is provided, a path through which carriers flow can be provided even if a break or the like occurs in a part of the finger line 42a adjacent to the one end edge region PA3. In addition, the electrode portions 424a and 424b positioned in the edge region PA3 at one end can be connected to the finger line 42a via the edge portion 423. In this way, the current collected by the finger line 42a located in the portion adjacent to the one end edge region PA3 in the electrode region EA is transmitted from the electrode portions 424a and 424b to the wiring member 142 via the edge portion 423. Thus, the current generated in the electrode area EA adjacent to the one end edge area PA3 can be effectively transmitted to the electrode portions 424a and 424b. However, the present invention is not limited to this, and the electrode portions 424a and 424b in the first edge region PA1 may be directly connected to the finger line 42a without passing through the edge portion 423. Various other modifications are possible.

  The edge portion 423 is disposed to be inclined to the finger line 42a and the bus bar line 42b so that the width of the first edge region PA1 gradually increases toward the first or second edge 161, 162 side of the solar cell 150. May be. As an example, the first edge region PA1 may have a substantially triangular shape, and the two edges 423 that define the first edge region PA1 may have a substantially “V-shaped” shape. Accordingly, the outer end portions of the finger lines 42a may be disposed gradually away from each other in the two electrode regions EA adjacent to the first edge region PA1. In addition, the first edge region PA1 may have a shape that increases in width as it approaches the first or second edge 161, 162 of the solar cell 150 between the two electrode regions E. As a result, the width of the end of the electrode area EA adjacent to the first edge area PA1 is smaller than that of the other parts. As an example, the first edge region PA1 may have an isosceles triangle shape, and each electrode region EA may have a substantially octagonal shape.

  Accordingly, the wiring member 142 can be stably positioned in the first edge region PA1 while adhering to the edge portion 423. In the present embodiment, the end portion of the wiring member 142 that is not connected to the other solar cell 150 is extended to the inside of the first edge region PA1 through the end portion of the line portion 421 to be the first edge region PA1 or one end edge region. It is located inside PA3. Accordingly, the wiring member 142 can be stably fixed to the end portion of the line portion 421, and can be fixed to the first electrode 42 with sufficient adhesive force by the first pad portion 422a. On the other hand, if the end of the wiring member 142 is positioned at the end of the line portion 421 or does not reach the end of the line portion 421, the end of the wiring member 142 is positioned at the end of the line portion 421. There is a possibility that the first pad portion 422a is not stably attached. Alternatively, when the end portion of the wiring member 142 is extended to the second edge region PA2, problems such as an unnecessary short circuit may occur.

  As an example, in the first edge region PA1, the length of the wiring material 142 located in the first edge region PA1 may be larger than the length of the portion where the wiring material 142 is not located. That is, the ratio of the length L3 of the first edge region PA1 to the length L4 of the wiring member 142 located in the first edge region PA1 may be 1: 0.5 to 1: 1. As a result, the wiring member 142 can be stably attached to the first pad portion 422a. More specifically, the ratio of the length L3 of the first edge area PA1 to the length L4 of the wiring member 142 located in the first edge area PA1 may be 1: 0.6 to 1: 0.9. Good. By setting it within this range, the wiring member 142 can be stably attached to the first pad portion 422a and can be prevented from being extended to the second edge region PA2. However, the present invention is not limited to this.

  Further, the other end portion of the wiring member 42 may extend to the outside of the semiconductor substrate 160 through the first edge region PA1 (or the other end edge region PA4). That is, the wiring member 42 is extended from one end edge region PA3 to the first pad portion 422a adjacent to the other end edge region PA4 through the first pad portion 422a adjacent thereto, and subsequently to the first pad portion 422a and the other. It extends to the outside of the semiconductor substrate 160 through the edge region PA4.

  At this time, the wiring member 142 is positioned in a state where it is structurally coupled or attached to the pad portion 422. The wiring member 142 may be structurally coupled or attached to the line portion 421 and / or the electrode portions 424a and 424b in the one end and the other end edge regions PA3 and PA4, and is not structurally connected or attached. You may be located at. Even if the wiring member 142 is not structurally coupled or attached to the line portion 421 and / or the electrode portions 424a and 424b in the one end and other end edge regions PA3 and PA4, the line portion 421 and / or the electrode portions 424a and 424b They can be connected (eg, electrically connected) to them by overlapping contacts. This is because the coating layer 142b containing the solder substance in the wiring member 142 is well attached to the pad part 422 having a relatively wide width, but the line part 421 and / or the bus bar line 42b having a relatively narrow width. Alternatively, it may not be attached to the electrode portions 424a and 424b.

  Therefore, the coupling force between the bus bar line 42b and the wiring member 142 in the one end edge region PA3 and the other end edge region PA4 is such that the bus bar line 42b and the wiring member 142 in the region other than the one end edge region PA3 and the other end edge region PA4. It may be smaller than the binding force. In particular, the bonding strength between the electrode portions 424a and 424b of the bus bar line 42b and the wiring member 142 in the one end edge region PA3 and the other end edge region PA4 is such that the pad portion 422 (particularly, the first pad portion 422a) and the wiring member 142 It may be smaller than the binding force. Accordingly, a sufficient coupling force can be realized by the pad portion 422, and smooth electrical connection can be realized by a small electrode area in the one end edge region PA3 and the other end edge region PA4.

  The width (or width of one end or other end edge areas PA3, PA4) W8 of the first edge area PA1 located between the outermost finger lines 421a, 422a may be larger than the width W1 of the wiring member 142. Thereby, the wiring member 142 can be stably positioned in the first edge region PA1. In particular, the wiring member 142 can be positioned in the first edge region PA1 even when the wiring member 142 bends left and right in the first edge region PA1 during the attaching process of the wiring member 142.

  The width W8 of the first edge region PA1 may be 0.73 mm to 3.8 mm. As an example, the width W8 of the first edge region PA1 may be 0.73 mm to 2 mm. Alternatively, the ratio of the width W1 of the wiring member 142 to the width W8 of the first edge region PA1 may be 1: 1.46 to 1: 15.2 (for example, 1: 1.46 to 1: 5). Good. In such a range, the wiring material 142 can be stably positioned in the first edge region PA1.

  Alternatively, when the width W8 of the first edge region PA1 is L and the edge distance D is D, L and D can satisfy the following Expression 1. Here, the edge distance D refers to the inner edge of the first edge region PA1 located on the inner side of the outermost finger lines 421a and 422a (or the pad part 422 located in this part) and the edge of the solar cell 150 ( More specifically, it means the distance between the first or second edge 161, 162).

[Formula 1]

  This is because the phenomenon that the wiring member 142 is bent more frequently occurs as the edge distance D becomes larger, and the width W8 of the first edge region PA1 must be sufficiently secured as the edge distance D becomes larger. However, the present invention is not limited to this.

  The width of the edge portion 423 is smaller than the width of the line portion 421. As an example, the width of the line portion 421 may have a value that is twice or more the width of the edge portion 423. Then, the sum of the widths of the two edge portions 423 is equal to or smaller than the width of the line portion 421 at a portion branched from the line portion 421 into two. As a result, the width of the edge portion 423 can be minimized and the width of the bus bar line 42b can be prevented from becoming wide at the portion where the line portion 421 and the two edge portions 423 are connected. As an example, the width W4 of the line part 421 may be 2 to 10 times the width of the edge part 423. Alternatively, as an example, the line width of the edge 423 may be 35 μm to 120 μm.

  Alternatively, the width of the edge 423 may be smaller than the width of the finger line 42a, or similar or identical to the width of the finger line 42a. As an example, the width of the edge 423 may be two times or less (as an example, 0.5 to 2 times) the width of the finger line 42a. Thus, problems such as an increase in optical loss due to the edge 423 can be prevented while realizing the effect of the edge 423. However, the present invention is not limited to this, and it is sufficient that the width of the edge portion 423 has a width that allows a current to flow by connecting the finger lines 42a.

  In this embodiment, the bus bar line 42b may include electrode portions 424a and 424b that are positioned in the one end edge region PA3 and the other end edge region PA4, respectively. The wiring member 142 overlaps and contacts the electrode portions 424a and 424b located in the one end edge region PA3 and the other end edge region PA4, or the wiring member 142 is electrically connected. As a result, the electrode portions 424a and 424b provide a path through which a current can flow through the wiring member 142. Therefore, it can be said that the electrode portions 424a and 424b constitute part of the bus bar line 424b.

  In the present embodiment, the current generated in the electrode area EA adjacent to the one end edge area PA3 and the other end edge area PA4 via the electrode portions 424a and 424b located in the one end edge area PA3 and the other end edge area PA4. Can be transmitted to the wiring member 142. As a result, a portion of the electrode area EA located in a portion adjacent to the one end edge area PA3 and the other end edge area PA4 (that is, two end edge areas PA3 provided side by side in a direction parallel to the finger line 42a). A part of the electrode area EA located between and / or a part of the electrode area EA located between two other edge areas PA3 provided side by side in a direction parallel to the finger line 42a). The current can be effectively transmitted to the wiring member 142 by the electrode portions 424a and 424b. As a result, even when the first edge region PA1 (or the one end edge region PA3 and the other end edge region PA4) is provided in order to improve the adhesive force or bonding force of the wiring member 142, a reduction in efficiency that may occur due to this. Etc. can be prevented. Therefore, the efficiency of the solar cell 150 can be improved and the output of the solar cell panel 100 can be improved.

  Unlike the present embodiment, when the electrode portions 424a and 424b are not provided in the one-end edge region PA3 and the other-end edge region PA4, they are generated in the electrode area EA adjacent to the one-end edge region PA3 and the other-end edge region PA4. The collected current is transmitted to the wiring member 142 after being collected at the first pad portion 422a. For this reason, it is difficult to effectively collect the current generated in the electrode area EA adjacent to the one end edge area PA3 and the other end edge area PA4.

  At this time, in the present embodiment, it is sufficient that the electrode portions 424a and 424b have a shape that can be connected to the finger line 42a, the bus bar line 42b, or the wiring member 142. Accordingly, the electrode portions 424a and 424b are positioned in the one end edge region PA3 and the other end edge region PA4 with a density lower than that of the finger lines 42a in the electrode region EA.

  More specifically, the one end edge region PA3 and the other end edge region PA4 may be formed symmetrically with respect to the center line of the semiconductor substrate 160 (that is, the center line parallel to the finger lines 42a). Thus, in this embodiment, one end edge region PA3 and the other end edge region PA4 are provided on both side edges (that is, the first and second edges 161 and 162) of the semiconductor substrate 160, respectively. It is possible to effectively prevent a decrease in adhesion force with the wiring member 142 that may occur in the portion.

  In the present embodiment, the electrode portion 424a located in the edge region PA3 at one end has an opening inside, and the outermost end portion of the electrode portion 424a is located on the same line as the outermost finger line 421a adjacent thereto. Or may be located outside (ie, closer to the first edge 161 of the semiconductor substrate 160). Similarly, the electrode part 424b located in the other end edge area PA has an opening therein, and the outermost end part of the electrode part 424b is located on the same line as the outermost finger line 422a adjacent thereto. Alternatively, it may be located on the outer side (that is, closer to the second edge 162 of the semiconductor substrate 160). Accordingly, the electrode portions 424a and 424b can be stably connected to the wiring member 142. Accordingly, the current generated in the electrode area EA adjacent to the one end and the other end edge areas PA3 and PA4 can be more stably transmitted to the wiring member 142.

  Thus, since the electrode portions 424a and 424b located in the one end edge region PA3 and the other end edge region PA4 each have an opening (a portion where no electrode is formed), the electrode portion located in the electrode region EA As compared with the above, the electrode portions 424a and 424b having a lower density can be formed, and the finger line 42a can be smoothly connected. The outermost ends of the electrode portions 424a and 424b (that is, the outer end portion of the second electrode portion 4242 and the outer end portion of the second electrode portion 4243) are aligned with the outermost finger line 42a, or this Therefore, the current collected on the side of the finger line 42a adjacent to the outside does not remain and can be effectively transmitted to the wiring member 142.

  In the present embodiment, the electrode portion 424a formed by the one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 have different shapes (that is, an asymmetric shape). For this reason, the opening part of the electrode part 424a located in one end edge area | region PA3 and the opening part of the electrode part 424b located in other end edge area | region PA4 can also have a mutually different shape or arrangement | positioning. As described above, the end portion of the wiring material 142 is located in the one end edge region PA3, and the wiring material 142 is extended to the outside of the semiconductor substrate 160 in the other end edge region PA4. For this reason, the length of the wiring member 142 located in the one end edge region PA3 is different from the length of the wiring member 142 located in the other end edge region PA4. More specifically, the length of the wiring member 142 located in the other end edge region PA4 is larger than the length of the wiring member 142 located in the one end edge region PA. In consideration of this, the electrode portion 424a formed by the one end edge region PA3 and the electrode portion 424b positioned in the other end edge region PA4 are formed into separate shapes.

  More specifically, in one end edge region PA3, the electrode portion 424a is in the direction intersecting the first electrode portion 4241 from the first electrode portion 4241 located on the inner side of the outermost finger line 421a, and the first electrode portion 4241. A second electrode part 4242 may be included that extends to the same line as the outermost finger line 421a or to the outside.

  At this time, the first electrode portion 4241 is parallel to the finger line 42a, or intersects with the line portion 421 of the bus bar line 42b (for example, orthogonal), and is a portion of the electrode area EA located on both sides of the edge area PA3. It may be connected (directly connected or connected via the edge 423) to the finger line 42a located inside. Accordingly, the first electrode portion 4241 is connected to the finger line 42a located in the portion of the electrode area EA located on both sides of the one end edge area PA3, and the current generated in the portion of the electrode area EA is 1 electrode part 4241 may be transmitted. Thus, an opening is provided between the first electrode portion 4241, the first pad portion 422a located at the inner end, and the edge portion 423.

  In addition, the second electrode portion 4242 may be provided so as to intersect with the finger line 42a (as an example, orthogonal) or in parallel with the line portion 421 of the bus bar line 42b. Since the second electrode portion 4242 is extended from the first electrode portion 4241 at a position separated from the first pad portion 422a of the bus bar line 42b, the first pad portion 422a increases the bonding force with the wiring member 142. In particular, unnecessary interference can be prevented, the electrode area can be reduced, and the material cost can be reduced. Further, the second electrode portion 4242 is positioned so as to pass through the center of the first electrode portion 4241, and the connection area or probability with the wiring member 142 can be greatly increased. Accordingly, the current transmitted through the first electrode portion 4241 can be stably transmitted to the wiring member 142.

  Accordingly, a kind of opening is formed between one side of the first electrode portion 4241 (left side of the drawing), the second electrode portion 4242 adjacent to one side of the first electrode portion 4241, and the first edge 161. . A kind of opening is also formed between the other side of the first electrode part 4241, the second electrode part 4242 adjacent to the other side of the first electrode part 4241, and the first edge 161.

  At this time, as an example, in the first edge region PA1, the position of the first electrode portion 4241 in the direction parallel to the line portion 421 is closer to the outermost finger line 42b than the inner end portion of the first edge region PA1. May be located. That is, in the direction parallel to the line portion 421, the length L3 of the first edge region PA1: The distance between the first electrode portion 4241 and the first pad portion 422a is 1: 0.5 to 1: 1. May be. More specifically, the length L3 of the first edge region PA1: the distance between the first electrode portion 4241 and the first pad portion 422 may be 1: 0.6 to 1: 0.9. . In this case, when the wiring member 142 is positioned on the second electrode portion 4242 across the first electrode portion 4241, the wiring member 142 can be attached so as to pass through the first pad portion 422a stably. Further, it is possible to prevent the wiring member 142 from extending to the second edge area PA2. However, the present invention is not limited to this.

  In the other end edge region PA4, the electrode part 424b may include a third electrode part 4243 positioned on the same line as the outermost finger line 422a or on the outer side. Accordingly, the wiring member 142 can be extended to the outside of the semiconductor substrate 160 across the third electrode portion 4243. At this time, the third electrode portion 4243 is provided in a direction parallel to the finger line 42a or intersecting (for example, orthogonal) to the line portion 421 of the bus bar line 42b, and is located on both sides of the other end edge region PA4. It may be connected (directly connected or connected via the edge 423) to the finger line 42a located in the portion of the area EA.

  In this way, the third electrode portion 4243 is connected to the finger line 42a located in the portion of the electrode area EA located on both sides of the other end edge area PA4. Accordingly, the current generated in the portion of the electrode area EA can be stably transmitted to the first electrode portion 4241 through the third electrode portion 4243. In the other end edge region PA4, since the wiring member 142 extends to the outside of the semiconductor substrate 160, even if it has only the third electrode portion 4243, it can be stably connected to the finger line 42a. Considering this, in the other end edge region PA4, the structure of the electrode portion 424b can be simplified to reduce the manufacturing cost, and the manufacturing process can be simplified. Thus, an opening is provided between the third electrode portion 4243, the first pad portion 422a located at the inner end, and the edge portion 423. At this time, the distance between the third electrode part 4243 and the first pad part 422a adjacent thereto is larger than the distance between the first electrode part 4241 and the first pad part 422a adjacent thereto. Accordingly, the area of the opening formed between the first pad portion 422a and the third electrode portion 4243 located in the other end edge region PA4 is located in the one end edge region PA3, and the first pad portion 422a It may be larger than the area of the opening formed between the first electrode portion 4241 and the first electrode portion 4241.

  In the drawing, the electrode portions 424a and 424b are illustrated as being located on the same line as the outermost finger lines 421a and 422a or extended to the same line. However, the present invention is not limited to this, and the electrode portions 424a and 424b may be extended so as to protrude from the outermost finger lines 421a and 422a as shown in FIGS. Details thereof will be described later.

  Thus, in the present embodiment, in the one end edge region PA3, the second electrode portion 4242 in the direction parallel to the line portion 421 is located on the same line as or outside the outermost finger line 421a, and the other end edge region PA4. In the example, the third electrode portion 4243 in the direction intersecting with the line portion 421 is located on the same line as the outermost finger line 422a or on the outer side. This is because the end of the wiring member 142 is located in the one end edge region PA3 and the wiring member 142 is extended to the outside across the other end edge region PA4. According to this, even if the arrangement of the wiring member 142 is changed, the wiring member 142 and the electrode portions 424a and 424b can be stably connected.

  The widths of the electrode portions 424a and 424b located in the edge region PA may be larger than the width of the finger lines 42a, or similar or identical to the finger lines 42a, and smaller than the pitch of the finger lines 42a. As an example, the width of the electrode portions 424a and 424b may be twice or less (as an example, 0.5 to 2 times) the width of the finger line 42a. Alternatively, the width of the wiring member 142 may be larger than the width of the electrode portions 424a and 424b. Alternatively, the distance ratio between the width of the electrode portions 424a and 424b and the other electrode portions, the width of the wiring member 142, the pitch, etc. is the distance between the finger line 42a and the width of the other electrode portions, the wiring member 142, the pitch, etc. The ratio can be applied as it is. Accordingly, problems such as an increase in optical loss due to the electrode portions 424a and 424b can be prevented while realizing the effects due to the electrode portions 424a and 424b. However, the present invention is not limited to this, and it is sufficient that the electrode portions 424a and 424b have a width that allows a current to flow smoothly.

  In this embodiment, the thickness of the bus bar line 42b may be 3 μm to 45 μm. The thickness of the bus bar line 42b may be within a range that can be easily formed during the process and can have a desired specific resistance. However, the present invention is not limited to this, and the thickness and the like of the bus bar line 42b may be variously changed according to changes in process conditions, the size of the solar cell 150, the constituent material of the bus bar line 42b, and the like. .

  In the present embodiment, the finger lines 42a and the bus bar lines 42b may be formed of separate layers. That is, the finger line 42a may be formed of a layer different from the line part 421, the pad part 422, and the electrode parts 424a and 424b constituting the bus bar line 42b. The edge part 423 may constitute a part of the finger line 42a and may be constituted of the same layer as the finger line 42a, or may constitute a part of the bus bar line 42b and consist of the same layer as the bus bar line 42b. . For example, as shown by an enlarged circle at the top of FIG. 9, the bus bar line 42b can be formed first, and then the finger line 42a can be formed on at least a part of the bus bar line 42b. In this embodiment, the finger line 42a located on one side (for example, the left side of the drawing) and the finger line 42a located on the other side (for example, the right side of the drawing) are located apart from each other with respect to the bus bar line 42b. . Thus, if there is a portion where the finger line 42a is not formed on the bus bar line 42b, the manufacturing cost of the finger line 42a can be minimized. However, the present invention is not limited to this, and the finger lines 42a can be positioned across the entire bus bar line 42b.

  The finger line 42a and the bus bar line 42b may be made of the same material or different materials. As an example, when the finger line 42a and the bus bar line 42b are formed by printing, the paste for forming the bus bar line 42b has a relatively low viscosity, and the paste for forming the finger line 42a is It can have a relatively high viscosity. For this reason, the thickness of the finger line 42a may be higher than the thickness of the bus bar line 42b after firing. Therefore, as described above, if the finger line 42a is formed after the bus bar line 42b is first formed, the bus bar line 42b can be formed more stably.

  As an example, the content of metal (for example, silver) in the paste for forming the finger line 42a may be larger than the content of metal (for example, silver) in the paste for forming the bus bar line 42b. This can reduce the resistance of the finger line 42a directly related to carrier collection, improve carrier collection efficiency, reduce the metal content of the bus bar line 42b, and reduce the manufacturing cost.

  At this time, the finger line 42 a of the first electrode 42 may be formed through the passivation film 22 and the antireflection film 24, and the bus bar line 42 b may be formed on the passivation film 22 and the antireflection film 24. In this case, the opening (reference numeral 102 in FIG. 3) may be formed in a shape corresponding to the finger line 42a in a portion where the bus bar line 42b is not located, and not formed in a portion where the bus bar line 42b is located. Good. At this time, the first conductivity type region 20 may have a shape corresponding to a portion where the opening 102 is formed. That is, the first conductivity type region 20 is formed in the electrode region EA so as to have a shape corresponding to the finger line 42a, and may not be formed in a portion corresponding to the bus bar line 42b. In this case, the line portion 421, the pad portion 422, and the electrode portions 424a and 424b (including the edge portion 423 when the edge portion 423 forms part of the bus bar line 42b) constituting the bus bar line 42b are included in the passivation film. The first conductivity type region 20 may not be formed in a portion corresponding to this formed on 22 and the antireflection film 24. Then, the line part 421 and the pad part 422 constituting the bus bar line 42b (including the edge part 423 when the edge part 423 constitutes a part of the bus bar line 42b) constitutes a floating electrode. Can do.

  However, the present invention is not limited to this, and it is also possible to form the bus bar line 42b after first forming the finger line 42a. Alternatively, as shown by the enlarged circle at the bottom of FIG. 9, the finger lines 42a and the bus bar lines 42b may be formed together in one process and configured as the same layer made of the same material. Various other modifications are possible.

  Further, the first electrode 42 is connected to the end of the finger line 42a, and an edge line 42c that partitions the electrode area EA and the second edge area PA2 at a portion adjacent to the third and fourth edges 163 and 164 is formed. Can be included. The edge line 42c is spaced apart from the third and fourth edges 163 and 164 at a portion adjacent to the third and fourth edges 163 and 164, and is the same as or similar to the third and fourth edges 163 and 164. Can have a shape. At this time, the edge line 42 c connects the ends of the finger lines 42 a adjacent to the third and fourth edges 163 and 164.

Each frame has a uniform width between the third and fourth edges 163 and 164 and the edge line 42c, and between the first and second edges 161 and 162 and the outermost finger line 42a. The second edge area PA2 to be performed may be located. The width W9 of the second edge region PA2 may be 0.5 mm to 1.5 mm. If the width W9 of the second edge area PA2 is less than 0.5 mm, problems such as unnecessary shunts may occur. If the width of the second edge region PA2 exceeds 1.5 m, the area of the ineffective region may increase and the efficiency of the solar cell 150 may decrease. However, the present invention is not limited to this.
The width of the edge line 42c may be similar to or the same as the width of the finger line 42a. The width and thickness of the finger line 42a, the relationship with other electrode portions and the wiring member 142, and the like can be applied to the edge line 42c as they are. The edge line 42c may constitute a part of the finger line 42a, for example.

  In this embodiment, if the width W1 of the wiring member 142 is W and the edge distance D is D, the above W and the above D can satisfy the following formula 2.

[Formula 2]

  As described above, in the first pad portion 422a of the first electrode 42 where the wiring material 142 is located, a force is applied to the wiring material 142 in a direction away from the solar cell 150, and the adhesion force between the wiring material 142 and the first electrode 42 is applied. Can be reduced. That is, as shown in FIG. 10, when the width W1 of the wiring member 142 is increased, the degree to which the solar cell 150 or the semiconductor substrate 160 is bent increases. For reference, in FIG. 10, 300 wire is a case where the width W1 of the wiring member 142 is 300 μm, 330 wire is a case where the width W1 of the wiring member 142 is 330 μm, and 400 wire is a width W1 of the wiring member 142 is 400 μm. Represents the case. When the width W1 of the wiring member 142 is increased in this way, a larger force acts on the wiring member 142 in the direction away from the solar cell 150 at the first pad portion 422a of the first electrode 42. Adhesion can be reduced. In order to prevent such a decrease in adhesion, in this embodiment, the edge distance D is sufficiently secured and the stress applied to the first electrode 42 is minimized.

  That is, the present inventors indicate that the adhesive force between the wiring member 142 and the first electrode 42 has a sufficient value only when the edge distance D increases as the width W1 of the wiring member 142 increases. The range of the edge distance D according to the heading and the width W1 of the wiring member 142 is presented as in Expression 2. Here, as described above, since the wiring member 142 is connected to the first pad portion 422a with a sufficient area and a sufficient bonding force, the distance between the first pad portion 422a and the edge of the semiconductor substrate 160 is set as an edge. This is the distance D.

  Furthermore, the present inventors measured the adhesive force with the wiring material 142 at the first pad portion 422a of the first electrode 42 while changing the width W1 and the edge distance D of the wiring material 142. At this time, a case where the adhesive force has a value greater than a certain value (for example, a value greater than or equal to 1.5 N (more preferably greater than or equal to 2 N)) was found and represented by x display in FIG. Then, as shown in FIG. 11, a portion including the range of the edge distance D by the width W1 of the wiring member 142 is found so as to include the portion where the x display is located, and the above-described lower limit line and upper limit line of the edge distance Equation 2 was derived.

  As a result, when the width W1 of the wiring member 142 has a constant value, the wiring member 142 having the wire form is stabilized at the end of the first electrode 42 if the edge distance D belongs to the range of the above-described formula 2. It is possible to maintain the attached state. Therefore, according to the present embodiment, the wiring material 142 having the wire form is used to realize various effects, and the edge distance D is adjusted to improve the adhesion with the wiring material 142. it can.

  At this time, since the width W1 of the wiring member 142 is 250 μm to 500 μm, the edge distance D can have a value of 2.37 mm to 21.94 mm. More specifically, when the width W1 of the wiring member 142 is 250 μm or more and less than 300 μm, the edge distance D can be 2.37 mm to 9.78 mm. When the width W1 of the wiring member 142 is 300 μm or more and less than 350 μm, the edge distance D may be 3.99 mm to 12.94 mm. When the width W1 of the wiring member 142 is 350 μm or more and less than 400 μm, the edge distance D may be 5.06 mm to 15.98 mm. When the width W1 of the wiring member 142 is 400 μm or more and less than 450 μm, the edge distance D may be 5.69 mm to 18.96 mm. When the width W1 of the wiring member 142 is 450 μm to 500 μm, the edge distance D may be 5.94 mm to 21.94 mm. In such a range, the above-described Expression 2 can be satisfied and excellent adhesion can be achieved.

  As an example, when the width W1 of the wiring member 142 is 250 μm or more and less than 300 μm, the edge distance D may be 4 mm to 9.78 mm. When the width W1 of the wiring member 142 is 300 μm or more and less than 350 μm, the edge distance D may be 6 mm to 12.94 mm. When the width W1 of the wiring member 142 is 350 μm or more and less than 400 μm, the edge distance D may be 9 mm to 15.98 mm. When the width W1 of the wiring member 142 is 400 μm or more and less than 450 μm, the edge distance D may be 10 mm to 18.96 mm. When the width W1 of the wiring member 142 is 450 μm to 500 μm, the edge distance D may be 12 mm to 21.94 mm. In such a range, it can have sufficient adhesive force more stably. In particular, in this embodiment, when the width W1 of the wiring member 142 is 350 μm or more and less than 400 μm, the edge distance D may be 9 mm to 15.98 mm. In this case, the output of the solar cell panel 100 can be maximized. However, the present invention is not limited to this.

  At this time, since the first pad portion 422a is located at the end of the bus bar line 42b where the wiring member 142 is located in this embodiment, the first pad portion 422a and the first or second edge 161, 162 of the solar cell 150 are provided. The edge distance D between and can satisfy the above-described expression 2 and range.

  The inventor has also found that the number of wiring members 142 (or the number of bus bar lines 42b) located on one surface of the solar cell 150 has a certain relationship with the width W1 of the wiring member 142. FIG. 12 is a graph showing the output of the solar cell panel 100 measured while changing the width W1 and the number of wiring members 142. FIG. It can be seen that when 6 to 33 wiring members 142 having a width W1 of 250 μm to 500 μm are provided, the output of the solar cell panel 100 has an excellent value. At this time, when the width W1 of the wiring member 142 is increased, the number of necessary wiring members 142 may be reduced.

  For example, when the width W1 of the wiring member 142 is 250 μm or more and less than 300 μm, the number of wiring members 142 (the number of wiring members 142 based on one surface of the solar cell 150) may be 15 to 33. . When the width W1 of the wiring member 142 is 300 μm or more and less than 350 μm, the number of the wiring members 142 may be 10 to 33. When the width W1 of the wiring member 142 is 350 μm or more and less than 400 μm, the number of the wiring members 142 may be 8 to 33. When the width W1 of the wiring member 142 is 400 μm to 500 μm, the number of wiring members 142 may be 6 to 33. And if the width W1 of the wiring material 142 is 350 micrometers or more, even if the number of the wiring materials 142 exceeds 15, the output of the solar cell panel 100 does not increase any more. In addition, as the number of wiring members 142 increases, the solar cell 150 may become a burden. Considering this, when the width W1 of the wiring member 142 is 350 μm or more and less than 400 μm, the number of the wiring members 142 can be 8 to 15. When the width W1 of the wiring member 142 is 400 μm to 500 μm, the number of the wiring members 142 may be 6 to 15. At this time, in order to further improve the output of the solar cell panel 100, the number of the wiring members 142 may be 10 or more (for example, 12 to 13). However, the present invention is not limited to this, and the number of wiring members 142 and the number of bus bar lines 42b thereby may have various values.

  At this time, the pitch of the wiring member 142 or the bus bar line 42b can be set to 4.75 mm to 26.13 mm. This takes into account the width W1 and the number of wiring members 142. For example, when the width W1 of the wiring member 142 is 250 μm or more and less than 300 μm, the pitch of the wiring member 142 may be 4.75 mm to 10.45 mm. When the width W1 of the wiring member 142 is 300 μm or more and less than 350 μm, the pitch of the wiring member 142 may be 4.75 mm to 15.68 mm. When the width W1 of the wiring member 142 is 350 μm or more and less than 400 μm, the pitch of the wiring member 142 may be 4.75 mm to 19.59 mm. When the width W1 of the wiring member 142 is 400 μm to 500 μm, the pitch of the wiring member 142 may be 4.75 mm to 26.13 mm. More specifically, when the width W1 of the wiring member 142 is 350 μm or more and less than 400 μm, the pitch of the wiring member 142 may be 10.45 mm to 19.59 mm. When the width W1 of the wiring member 142 is 400 μm to 500 μm, the number of the wiring members 142 may be 10.45 mm to 26.13 mm. However, the present invention is not limited to this, and the pitch of the wiring member 142 and the resulting pitch of the bus bar line 42b may have various values.

  In the present embodiment, the first electrode 42, the wiring material 142, the electrode area EA, the edge area PA, and the like are in the horizontal direction (direction parallel to the finger line 42a) and the vertical direction (direction parallel to the bus bar line 42b or the wiring material 142). May be positioned symmetrically with respect to each other. As a result, a current flow can be stably realized. However, the present invention is not limited to this.

  In the above, the first electrode 42 has been mainly described with reference to FIGS. The second electrode 44 may include a finger line, a bus bar line, and an edge line corresponding to the finger line 42a, the bus bar line 42b, and the edge line 42c of the first electrode 42, respectively. The contents relating to the finger line 42a, bus bar line 42b and edge line 42c of the first electrode 42 can be applied to the finger line, bus bar line and edge line of the second electrode 44 as they are. At this time, the description related to the first conductivity type region 20 related to the first electrode 42 may be the description related to the second conductivity type region 30 related to the second electrode 44. The description related to the first passivation film 22 and the antireflection film 24 related to the first electrode 42 and the opening 102 is related to the second passivation film 30 related to the second electrode 44 and the opening 104. Also good.

  At this time, the finger line 42a of the first electrode 42, the line portion 421 of the bus bar line 42b, and the width, pitch, number, etc. of the pad portion 442 are respectively the finger line 44a of the second electrode 44, the line portion of the bus bar line 44b, and the pad. It may be the same as the width, pitch, number, etc. of the parts. Alternatively, the finger line 42a of the first electrode 42, the line part 421 of the bus bar line 42b, and the width, pitch, and number of the pad part 442 are respectively the finger line 44a of the second electrode 44, the line part of the bus bar line 44b, and the pad part. May be different from the width, pitch, number, etc. As an example, the width of the electrode portion of the second electrode 44 with relatively little incident light may be larger than the width of the corresponding electrode portion of the first electrode 42, and the pitch of the second electrodes 44 may be The pitch of the electrode portions of the first electrode 42 corresponding to this may be smaller. Various other modifications are possible. However, the number and pitch of the bus bar lines 42b of the first electrode 42 may be the same as the number and pitch of the bus bar lines of the second electrode 44, respectively. Further, the planar shapes of the first electrode 42 and the second electrode 44 may be different from each other, and various other modifications are possible. As an example, the length of the pad portion 422 located on the back surface of the semiconductor substrate 10 may be larger than the length of the pad portion 422 located on the front surface of the semiconductor substrate 10. This is because it is difficult to increase the length from the burden of light loss on the front surface of the semiconductor substrate 10, but the burden of light loss is relatively small on the back surface.

  According to the present embodiment, the wiring member 142 in the form of a wire can be used, light loss can be minimized by diffuse reflection, the pitch of the wiring member 142 can be reduced, and the carrier movement path can be reduced. Thereby, the efficiency of the solar cell 150 and the output of the solar cell panel 100 can be improved. At this time, the edge distance D of the first pad portion 422a is limited by the width of the wiring member 142, and the adhesion between the wiring member 142 having a wire form and the first electrode 42 can be improved. Accordingly, damage to the solar cell 150 that may occur when the wiring member 142 is separated from the first electrode 42 can be prevented, and the solar cell 150 can have excellent electrical characteristics and excellent reliability. Further, the number of wiring members 142 is limited by the width W1 of the wiring member 142, and the output of the solar cell panel 100 can be maximized.

In the present embodiment, the electrode portions 424a and 424b are positioned on the same line as or outside of the outermost finger lines 421a and 422a in the one end edge region PA3 and the other end edge region PA4, and the connection structure with the wiring member 142 is stable. Can be formed. Wiring current generated in the electrode area EA adjacent to the one end edge area PA3 and the other end edge area PA4 via the electrode portions 424a and 424b located in the one end edge area PA3 and the other end edge area PA4 It can be effectively transmitted to the material 142. Thus, the current generated in the electrode area EA located adjacent to the one end edge area PA3 and the other end edge area PA4 is effectively transmitted to the wiring member 142 by the electrode portions 424a and 424b. Therefore, even when the first edge region PA1 (or the one end edge region PA3 and the other end edge region PA4) is provided in order to improve the adhesive force or bonding force of the wiring member 142, a reduction in efficiency that can be caused by this. Etc. can be prevented. Thereby, the efficiency of the solar cell 150 can be improved and the output of the solar cell panel 100 can be improved.
Further, the electrode portions 424a located in the one end edge region PA3 and the electrode portions 424b located in the other end edge region PA4 are separated from each other, thereby simplifying the electrode structure while stably forming the connection structure of the wiring members 142. be able to.

  Hereinafter, a solar cell and a solar cell panel including the solar cell according to another embodiment of the present invention will be described in detail with reference to the accompanying drawings. Since the above description can be applied as it is to the same or very similar part to the above description, the detailed description is omitted, and only different parts will be described in detail. And what combined the Example mentioned above or the example which changed this, and the following Example or the example which changed this also belongs to the scope of the present invention. In the following description, the first electrode is taken up and explained, but the same illustration and explanation can be applied to the second electrode.

  FIG. 13 is a partial front plan view of a solar cell according to another embodiment of the present invention. FIG. 13 (a) shows one end edge region PA3, and FIG. 13 (b) shows the other end edge region PA4.

  Referring to FIG. 13A, the second electrode portion 4242 further protrudes toward the first edge 161 from the outermost finger line 421a in the one end edge region PA3. According to this, the connection area or probability with the wiring member 142 can be further improved.

  Referring to FIG. 13B, the third electrode portion 4243 includes a portion further protruding toward the second edge 162 than the outermost finger line 422 a in the other end edge region PA. That is, the third electrode portion 4243 may have a shape protruding outward from the outermost finger line 422a while being connected to the outermost finger line 422a. In this embodiment, as an example, the center portion of the third electrode portion 4243 is parallel to the outermost finger line 422a, and the amount end portion of the third electrode portion 4243 is inclined with respect to the outermost finger line 422a. . However, the present invention is not limited to this, and the third electrode portion 4243 may have various shapes.

  FIG. 14 is a partial front plan view of a solar cell according to still another embodiment of the present invention.

  Referring to FIG. 14, the third electrode part 4243 has a thickness thicker than the outermost finger line 422a, and the outer edge of the third electrode part 4243 protrudes toward the second edge 162 from the outermost finger line 422a. Has the shape. Thus, when the thickness of the third electrode portion 4243 is relatively increased, the connection area with the wiring member 142 can be increased in the other end edge region PA4.

  FIG. 15 is a partial front plan view of a solar cell according to still another embodiment of the present invention.

  Referring to FIG. 15, the third electrode part 4243 has a thickness thicker than the outermost finger line 422a, the outer edge of the third electrode part 4243 is located on the same line as the outermost finger line 422a, and the third electrode The inner edge of the portion 4243 is located inside the outermost finger line 422a. Thus, if the thickness of the 3rd electrode part 4243 is made relatively large, the connection area with the wiring material 142 can be increased in other end edge area | region PA4.

  FIG. 16 is a partial front plan view of a solar cell panel according to still another embodiment of the present invention.

  Referring to FIGS. 16A and 16B, in this embodiment, the electrode portion 424a located in the one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 have a symmetrical shape. Yes. More specifically, an electrode portion 424a located in one end edge region PA3 and an electrode portion 424b located in the other end edge region PA4 are based on a virtual line passing through the center of the solar cell 150 and parallel to the finger line 42a. It is symmetrical. Accordingly, the opening of the electrode portion 424a located in the one end edge region PA3 and the opening of the electrode portion 424b located in the other end edge region PA4 can also have a symmetrical shape or arrangement.

  More specifically, referring to (a) of FIG. 16, the electrode portion 424 a in the edge region PA <b> 3 at one end includes the first electrode portion 4241 and the first electrode portion 4241 positioned on the inner side of the outermost finger line 421 a, A second electrode part 4242 may be included that extends in the direction intersecting with the first electrode part 4241 collinearly with the outermost finger line 421a or to the outside. The shape of the electrode portion 424a in the one-end edge region PA3 is the same as or very similar to the shape of the electrode portion 424a in the one-end edge region PA3 described with reference to FIG.

  In addition, referring to FIG. 16B, the electrode portion 424b in the other end edge region PA4 has a first electrode portion 4241 located on the inner side of the outermost finger line 421a and the first electrode portion 4241 from the first electrode portion 4241. A second electrode portion 4242 may be included that extends in the same direction as the outermost finger line 421a in the direction intersecting with the electrode portion 4241 or to the outside of the outermost finger line 421a. The shape of the electrode portion 424b in the other end edge region PA3 is the same as or very similar to the shape symmetrical to the shape of the electrode portion 424a in the one end edge region PA3 described with reference to FIG. .

  As a result, the first electrode portion 4241 located in the one end edge region PA3 and the first electrode portion 4241 located in the other end edge region PA4 have the same or very similar shape, length and width to each other at symmetrical positions. The second electrode part 4242 located in the edge region PA3 at one end and the second electrode part 4242 located in the edge region PA4 at the other end are symmetrical with each other at the same or very similar shape, length and width. Can be located.

  However, the present invention is not limited to this. For example, the electrode portion 424a located in the one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 are provided at symmetrical positions, but the shape, length, width, and the like may be different. Alternatively, the electrode portion 424a located in the one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 are not provided at exactly symmetrical positions, but at least one of its shape, length, and width is They may be identical or very similar to each other. Various other modifications are possible.

  In this embodiment, the electrode portion 424a located in the one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 are formed symmetrically with each other, thereby simplifying the structure and making the current flow uniform throughout. Can be made.

  FIG. 16 illustrates that each of the electrode portions 424a and 424b positioned in the one end edge region PA3 and the other end edge region PA includes the first electrode portion 4241 and the second electrode 4242, respectively. However, the present invention is not limited to this, and the electrode portions 424a and 424b located in the one end edge region PA3 and the other end edge region PA may have various shapes. This will be described with reference to FIG.

  FIG. 17 is a partial front plan view of a solar cell panel according to still another embodiment of the present invention.

  Referring to FIGS. 17A and 17B, in this embodiment, as in FIG. 16, the electrode portion 424a located in one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 are symmetrical. It has the shape of

  As an example, referring to FIG. 17A, the electrode portion 424 a in the one end edge region PA <b> 3 includes a first electrode portion 4241 positioned on the inner side of the outermost finger line 421 a, and the first electrode portion 4241. A second electrode portion 4242 that extends to the outside or the same line as the outermost finger line 421a in a direction intersecting the electrode portion 4241, and a third electrode that is located on the same line or the outer side from the outermost finger line 422a. And an electrode portion 4243. The second electrode portion 4242 reaches the third electrode portion 4243 and the second electrode portion 4242 and the third electrode portion 4243 are connected. The third electrode portion 4243 connects the outermost finger lines 421a located on both sides of the one end edge region PA3 to each other.

  Referring to (b) of FIG. 17, the electrode portion 424 b in the other end edge region PA <b> 4 includes a first electrode portion 4241 positioned on the inner side of the outermost finger line 421 a and the first electrode portion 4241, A second electrode portion 4242 that extends to the outside or the same line as the outermost finger line 421a in a direction intersecting the electrode portion 4241, and a third electrode that is located on the same line or the outer side from the outermost finger line 422a. And an electrode portion 4243. The second electrode portion 4242 reaches the third electrode portion 4243 and the second electrode portion 4242 and the third electrode portion 4243 are connected. The third electrode portion 4243 connects the outermost finger lines 421a located on both sides of the other end edge region PA4 to each other.

  In this embodiment, each of the one end edge region PA3 and the other end edge region PA4 has an opening in a closed space formed by the first electrode portion 4241, the second electrode portion 4242, the third electrode portion 4243, and the edge portion 423. Parts are provided. As an example, one opening may be located on each side of the second electrode portion 4242 facing the edge 423, and one opening may be located between the first electrode portion 4241 and the edge 423.

  In the drawing, the first electrode portion 4241 located in the one end edge region PA3 and the electrode portion 4241 located in the other end edge region PA4 are located at symmetrical positions with the same or very similar shape, length and width. ing. The second electrode part 4242 located in the one end edge area PA3 and the second electrode part 4242 located in the other end edge area PA4 are located symmetrically with each other and have the same or very similar shape, length and width. doing. In addition, the third electrode portion 4243 located in the one end edge region PA3 and the third electrode portion 4243 located in the other end edge region PA4 are located symmetrically with each other and have the same or very similar shape, length and width. doing.

  However, the present invention is not limited to this. For example, the electrode portion 424a located in the one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 are formed at positions symmetrical to each other. Its shape, length, width, etc. may be different. Alternatively, the electrode portion 424a located in the one end edge region PA3 and the electrode portion 424b located in the other end edge region PA4 are not formed at positions that are accurately symmetrical, but at least of the shape, length, and width thereof One may be the same or very similar. Various other modifications are possible.

  The detailed description of the first to third electrode portions 4241, 4242, and 4243 is the same as or very similar to the description of the first to third electrode portions 4241, 4242, and 4243 with reference to FIG. Omitted. The present invention may further include an embodiment in which the shape of the electrode portion 424a positioned in the one end edge region PA3 in FIG. 9 has the shape shown in FIG.

  In the present embodiment, both of the electrode portions 424a and 424b located in the one end edge region PA3 and the other end edge region PA4 include the first to third electrode portions 4241, 4242, and 4243, and diversify paths through which current can flow. , Current can flow more smoothly.

  FIG. 18 is a partial front plan view of a solar cell panel according to still another embodiment of the present invention.

  Referring to FIG. 18, in the present embodiment, the finger line 42 a located between two adjacent bus bar lines 42 b may not be continuously connected and may have a broken portion S in which a part is broken.

  At this time, the disconnection part S is formed in the finger line 42a located in the first electrode area EA1, and may not be formed in the finger line 42a located in the second electrode area EA2. In the first electrode area EA1, even if the finger line 42a has the disconnection portion S, the finger line 42a is connected to one bus bar line 42b or the wiring member 142, so that current can flow smoothly. Thereby, while not interrupting the flow of current in the first electrode region EA1, the area of the first electrode 42 can be reduced, and the manufacturing cost and the optical loss can be reduced. In the second electrode area EA2, since the bus bar line 42b or the wiring material 142 is connected only to one side, the current is smoothly supplied to the bus bar line 42b or the wiring material 142 located on the one side without the disconnection portion S. To be able to flow.

  The disconnection portion S of the finger line 42a may be provided in a central portion between two adjacent bus bar lines 42b. As a result, the current transfer path can be minimized.

  The width of the disconnected portion S may be 0.5 times or more of the pitch of the finger lines 42a and 0.5 times or less of the pitch of the bus bar lines 42b. If the width of the disconnection part S is less than 0.5 times the pitch of the finger lines 42a, the effect of the disconnection part S may be insufficient because the width of the disconnection part S is narrow. If the width of the disconnected portion S exceeds 0.5 times the pitch of the bus bar line 42b, the electrical characteristics may be deteriorated because the width of the disconnected portion S is large. As an example, the width of the disconnected portion S may be 1.5 mm to 3.2 mm. Within such a range, the effect of the disconnected portion S can be maximized. However, the present invention is not limited to this, and the width of the disconnected portion S may have various values.

  In each first electrode area EA1, the ratio of the number of finger lines 42a having the broken portion S to the number of finger lines 42a measured in a direction parallel to the bus bar line 42b is 0.33 times to 1 time. Also good. Within such a range, the effect of the disconnected portion S can be maximized. However, this invention is not limited to this, The ratio of the number mentioned above may be changed.

  In the drawing, an example in which the disconnection portion S is provided in each of the first electrode regions EA1 is shown, but the present invention is not limited to this. Of the plurality of first electrode regions EA1, the disconnection portion S may be provided in part, and the disconnection portion S may not be provided in other portions. Further, a plurality of disconnection portions S (that is, two or more) may be provided in one finger line 42a, and the position of the disconnection portion S may be different for each finger line 42a. In the drawing, an example is shown in which the first electrode region EA1 is provided with the disconnection portion S and the second electrode region EA2 is not provided with the disconnection portion S, but the present invention is not limited to this. Absent. Therefore, the disconnection portion S may be provided in each of the first and second electrode regions EA1 and EA2, or the disconnection portion S may be provided only in the second electrode region EA2. In the drawings and the above description, the first electrode 42 is illustrated and described, but this description can be applied to the second electrode 44 as it is.

  FIG. 19 is a partial front plan view of a solar cell according to still another embodiment of the present invention.

  Referring to FIG. 19, the finger line 42 a located between two adjacent bus bar lines 42 b in this embodiment includes portions having different line widths. The finger line 42a can have a narrow portion S1 having a relatively narrow width and a wide portion S2 having a relatively wide width.

  As an example, in this embodiment, the finger line 42a located in the first electrode area EA1 includes the narrow width part S1 and the wide width part S2, and the finger line 42a located in the second electrode area EA2 has a uniform width (for example, The same width as the wide portion S2). In the first electrode area EA1, since the finger line 42a is connected to the two adjacent bus bar lines 42b or the wiring member 142, current can flow smoothly. As a result, while the current flow is not obstructed in the first electrode region EA1, the area of the first electrode 42 can be reduced by the narrow width portion S1 of the first electrode 42, and the manufacturing cost and the optical loss can be reduced. In the second electrode area EA2, the bus bar line 42b or the wiring member 142 is connected only on one side, so that the current is supplied to the bus bar line 42b or the wiring member 142 located on the one side with a uniform width without providing the narrow portion S1. To flow smoothly.

  In the present embodiment, the narrow width portion S1 of the finger line 42a is located at a central portion between two adjacent bus bar lines 42b, and the width of the finger line 42a gradually increases toward each of the two bus bar lines 42b. ing. Thereby, the flow of current can be made smooth. However, this invention is not limited to this, The finger line 42a which comprises the narrow part S1 and the wide part S2 may have various shapes.

  In each first electrode area EA1, the ratio of the number of finger lines 42a having narrow portions to the number of finger lines 42a measured in a direction parallel to the bus bar line 42b is 0.33 times to 1 time. Also good. Within such a range, the effect of the narrow portion can be maximized. However, the present invention is not limited to this, and the ratio of the number described above may be changed.

  In the drawing, an example in which the narrow width portion S1 is provided in each of the first electrode regions EA1 is shown, but the present invention is not limited to this. Of the plurality of first electrode regions EA1, the narrow portion S1 may be provided in a part, and the narrow portion S1 may not be provided in other portions. In addition, a plurality of narrow portions S1 (that is, two or more) may be formed in one finger line 42a, and the positions of the narrow portions S1 may be different for each finger line 42a. Further, the drawing shows an example in which the first electrode area EA1 is provided with the narrow width portion S1, and the second electrode area EA2 is not provided with the narrow width portion S1, but the present invention is limited to this. Do not mean. Therefore, the narrow portion S1 may be provided in each of the first and second electrode regions EA1, EA2, and the narrow portion S1 may be provided only in the second electrode region EA2. Moreover, the disconnection part S shown in FIG. 18 may be located in such various modifications. Further, in the drawings and the above description, the first electrode 42 is illustrated and described, but such description can be applied to the second electrode 44 as it is.

  Hereinafter, the present invention will be described in more detail with reference to experimental examples of the present invention. The following experimental examples are presented for reference only, and the present invention is not limited thereto.

Experimental example

  A wiring member having a circular cross section and a width of 300 μm was attached to a solar cell having an edge distance of 7.5 mm. The adhesion force was measured while pulling the wiring material with an experimental device (for example, a tensile test device). The measured adhesion is shown in FIG.

  In FIG. 20, the horizontal axis represents distance, and the vertical axis represents adhesive force. At this time, the horizontal axis can be distinguished into three sections. The first section I is a section from the time when the experimental device is started and before the wire starts to be pulled after the wiring material is pulled, the second section II is a section where the experimental device actually pulls the wire, and the third section III is , Represents a section after the wire is separated from the pad portion. Therefore, the actual adhesive force can be confirmed from the second section II.

  The first section I is a section having a small distance, and in fact, no force is applied to the wiring material in the first section I.

  In the second section II, since the experimental apparatus is pulling the wiring material, the stress applied to the wiring material increases in proportion to the increase in distance. For this reason, a graph shows a mode that it rises gradually toward the highest point. More specifically, the adhesion force rises in the second section II, and suddenly falls with 2.058N as the highest point.

  The third section III is a section after the highest point of the adhesive force, and the wiring material is separated from the first pad portion, so that the stress applied to the wiring material suddenly decreases.

  Thus, in this example, it can be seen that the adhesion of the wiring material has a very excellent value of 2.058 N.

  Features, structures, effects, and the like as described above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be implemented by combining or modifying other embodiments by those who have ordinary knowledge in the field to which the embodiment belongs. Therefore, contents relating to such combinations and modifications should be construed as being included in the scope of the present invention.

Claims (25)

A plurality of solar cells each having a semiconductor substrate, a conductive type region provided on or on the semiconductor substrate, and an electrode connected to the conductive type region;
A plurality of wiring members electrically connected in proximity to two solar cells between the plurality of solar cells;
With
The number of the wiring members is 6 to 33,
The electrodes are extended in parallel in a first direction, and a plurality of finger lines including a plurality of outermost finger lines adjacent to both end edges of the semiconductor substrate, and a second crossing the first direction. A plurality of pad portions arranged in a direction and electrically connected to one of the plurality of wiring members;
One end edge region is disposed between one outermost pad portion of the plurality of pad portions and one side edge of the other side edge of the semiconductor substrate, and the other end edge region is another portion of the plurality of pad portions. Between the outermost pad portion and the other side edge of the semiconductor substrate,
The plurality of pad portions are connected to each other by a bus bar line having a width narrower than the width of the pad portion,
At the end of the one end edge region, the wiring member is connected to the outermost pad part, and the end of the wiring member is located inside the outermost finger lines,
At the end of the other end edge region, the wiring member is connected to the other outermost pad portion, and the wiring member extended in the second direction is the other outermost finger line crossing the other end edge region. Connected to
The one end edge region does not include an outermost finger line that crosses the one end edge region.   The coupling force between the bus bar line and the wiring material in each of the one end edge region and the other end edge region is the coupling between the bus bar line and the wiring material in a region other than the one end edge region and the other end edge region. The solar cell panel according to claim 1, which is smaller than force. The electrode portion disposed in the one end edge region is connected to the finger line disposed in a portion of two electrode regions adjacent to the one end edge region;
2. The solar cell panel according to claim 1, wherein the electrode portion disposed in the other end edge region is connected to the finger line disposed in a portion of two electrode regions adjacent to the other end edge region. An end of the wiring member is disposed in the one end edge region,
Wherein the wiring member through the other end edge region other solar cell also extends to an external circuit,
The solar cell panel according to claim 1, wherein the electrode portion disposed in the one end edge region and the electrode portion disposed in the other end edge region have different shapes. The electrode portion disposed in the edge region of the one end includes a first electrode portion located on the inner side of the outermost finger line, and the outermost portion along a direction intersecting the first electrode portion from the first electrode portion. A second electrode portion extending to the same line as the outer finger line or to the outside of the outer finger line,
In the other end edge region, the electrode part has a third electrode part located on the same line as the outermost finger line or on the outer side, and
The wiring member is located in the first electrode portion and the second electrode portion in the one end edge region;
The solar cell panel according to claim 4, wherein the wiring member is located on the third electrode portion in the other end edge region. The first electrode part and the third electrode part are parallel to the finger lines;
The second electrode part is orthogonal to the finger line;
The second electrode part is positioned so as to pass through the center of the first electrode part,
The wiring member is located across the first electrode part, and the end of the wiring member is located on the second electrode part;
The solar cell panel according to claim 5, wherein the wiring member crosses the third electrode portion. The end of the wiring member is located in the one end edge region,
Wherein the wiring member through the other end edge region other solar cell also extends to an external circuit,
2. The solar cell panel according to claim 1, wherein the electrode portion disposed in the one end edge region and the electrode portion disposed in the other end edge region have symmetrical shapes. Each of the one end edge region and the other end edge region has an inner end located inside the outermost finger line,
The solar cell panel according to claim 1, wherein the pad portion is located at the inner end portion. A width of the pad portion is equal to or larger than a width of the wiring member;
The solar cell panel according to claim 8, wherein a width of the pad portion is larger than a width of the finger line and the electrode portion.   The solar cell panel according to claim 8, wherein the wiring member extends to the one end edge region or the other end edge region located outside the pad portion located at the inner end portion.   The solar cell panel according to claim 1, wherein a length of the wiring member arranged in the one end edge region and a length of the wiring member arranged in the other end edge region are different from each other. Each of the one end edge region and the other end edge region has an inner end located inside the outermost finger line,
When the width of the wiring material is W, and the edge distance between the inner end of the one end or the other end edge region and the edge of the semiconductor substrate is D, the W and the D satisfy the following formulas: The solar cell panel according to claim 1.
13.732 · ln (W) −71.436−0.0000321462 · (W) 2 ≦ D ≦ 13.732 · ln (W) −71.436 + 0.0000321462 · (W) 2 (where W is a unit) Is μm, and the unit of D is mm.) The wiring material has a width of 250 μm to 500 μm,
The edge distance is 2.37 mm to 21.94 mm;
The solar cell panel according to claim 12, wherein the number of the wiring members is 6 to 33 on the basis of one surface of the solar cell. The width of the electrode part is equal to or larger than the width of the finger line, and smaller than the pitch of the finger lines,
The width of the wiring material is larger than the width of the electrode part,
2. The solar cell panel according to claim 1, wherein a width of the one end or the other end edge region is larger than a width of the wiring member between the outermost finger lines.   2. The solar cell panel according to claim 1, wherein the one end or the other end edge region has a shape in which a width gradually increases toward an edge of the semiconductor substrate. Further comprising an edge portion that divides them between the one end edge region and the electrode region, or between the other end edge region and the electrode region,
A plurality of the finger lines are connected to the edge,
The solar cell panel according to claim 1, wherein an electrode portion of the one end edge region or the other end edge region is connected to the finger electrode via the edge portion. A semiconductor substrate;
A conductive region provided on or on the semiconductor substrate;
An electrode connected to the conductive type region;
With
The electrodes are extended in parallel in a first direction, and a plurality of finger lines including a plurality of outermost finger lines adjacent to both end edges of the semiconductor substrate, and a second crossing the first direction. A plurality of pad portions that are arranged in a direction and are electrically connected to a wiring member that is connected to another solar cell or an external circuit;
One end edge region is disposed between the outermost pad portion between the plurality of pad portions and one side edge of the semiconductor substrate, and the other end edge region is the other outermost pad portion between the plurality of pad portions. And the other side edge of the semiconductor substrate,
The plurality of pad portions are connected to each other by a bus bar line having a width narrower than the width of the pad portion,
At the end of the one end edge region, the wiring member is connected to the outermost pad part, and the end of the wiring member is located inside the outermost finger lines,
In the end of the other end edge region, the wiring member is connected to the outermost pad portion, and the wiring member extended in the second direction is connected to the other outermost finger line. The electrode portion disposed in the one end edge region is connected to the finger line disposed in a portion of two electrode regions adjacent to the one end edge region;
The solar cell according to claim 17, wherein the electrode portion disposed in the other end edge region is connected to the finger line disposed in a portion of two electrode regions adjacent to the other end edge region.   18. The solar cell according to claim 17, wherein the electrode portion disposed in the one end edge region and the electrode portion disposed in the other end edge region have separate shapes or are symmetrical to each other. The electrode portion disposed in the edge region of the one end includes a first electrode portion located on the inner side of the outermost finger line, and the outermost portion along a direction intersecting the first electrode portion from the first electrode portion. A second electrode portion extending to the same line as the outer finger line or to the outside of the outer finger line,
20. The solar cell according to claim 19, wherein in the other end edge region, the electrode part has a third electrode part located on the same line as the outermost finger line or on the outer side.   The solar cell according to claim 17, wherein the one end edge region and the other end edge region include an opening having no finger line.   The solar cell of claim 17, wherein the outermost finger line extends continuously in the other end edge region.   The solar cell according to claim 17, wherein a distance from the outermost pad portion to the end portion of the substrate in the one end edge region or the other end edge region is 2.37 to 21.94 mm.   The solar cell according to claim 17, wherein a width of the one end edge region or the other end edge region is 0.73 to 3.8 mm. The width of the wiring member is 250～500Myuemu, the wiring member comprises a conductor having a circular section, the solar cell according to claim 17.