JP2014143391A - Solar cell, solar cell module and manufacturing method of solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily join a lead wire and a bus bar electrode and to reduce cost of manufacture.SOLUTION: On a rear side of a solar cell 3, two lines of bus bar electrodes 330 are provided in a direction 61. Each of the bus bar electrodes 330 includes: a plurality of first island-like electrodes 33 which are provided in parallel with each other in one line; and a plurality of second island-like electrodes 35 holding the first island-like electrode 33 therebetween at predetermined intervals and disposed side by side in the same line adjacently to the held first island-like electrode 33. The first island-like electrode 33 and the second island-like electrode 35 which are neighboring to each other, are alternately provided in the same line as one electrode set 350. In a rear side electrode layer 34, an opening 340 is formed correspondingly to each electrode set 350. Both ends of the electrode set 350 in the direction 61 are exposed by the opening 340, and both sides of the electrode set 350 in a direction 62 are covered by the rear side electrode layer 34.

Description

  The present invention relates to a solar cell, a solar cell module, and a method for manufacturing a solar cell, and more particularly to a solar cell using crystalline silicon, a solar cell module, and a method for manufacturing a solar cell.

  15 and 16 show an example of a crystalline silicon solar cell that uses conventional crystalline silicon. As shown in the figure, the conventional crystalline silicon solar cell includes a battery main body 91 that converts solar energy into electric power, a front electrode unit (not shown) and a back electrode laminated on both surfaces of the battery main body 91, respectively. A unit 92. The back electrode unit 92 includes at least one bus bar electrode 93 and a back electrode layer 94 connected around the bus bar electrode 93 and arranged to cover the back surface of the battery body 91. The bus bar electrode 93 is not formed in a strip shape by extending in a longitudinal direction along a predetermined first direction 95, but a plurality of electrode portions 931 arranged along the first direction 95 at predetermined intervals. Is provided. By doing so, the amount of conductive paste for electrode formation can be reduced, and the manufacturing cost of the battery can be reduced.

  The back electrode unit 92 forms a bus bar electrode 93 by applying a conductive paste by a screen printing method, and forms a back electrode layer 94 by applying another conductive paste. Then, the conductive paste is cured by sintering, whereby the bus bar electrode 93 and the back electrode layer 94 are formed.

  When several batteries are packaged in a battery module after the solar battery is manufactured in this way, the front electrode of one battery in several batteries and the bus bar electrode 93 provided on the back surface of the other battery are connected. As shown, adjacent batteries are connected in series with a plurality of strip-shaped conductors (ribbons) 96.

JP 2007-306041 A

  In the conventional solar cell, the back electrode layer 94 is formed so as to surround the bus bar electrode 93 and cover the back surface of the battery body 91, so that the back electrode layer 94 covers both ends of the electrode portion 931 in the first direction 95. It will cover up. For this reason, the overlapped portion becomes piled up. For example, as shown in FIG. 16, since the protruding portion 941 of the back electrode layer 94 is thick, a part 961 of the conductive wire 96 becomes high, and a gap 930 is formed between the bus bar electrode 93. For this reason, the conductive wire 96 cannot be welded to the bus bar electrode 93 well. In the bus bar electrode 93, the area that can be contacted by the conducting wire 96, that is, the welding area by the conducting wire 96 becomes small, so that the welding between the two becomes weak and the bonding strength is lowered, which adversely affects the reliability of the product.

  The present invention has been made in view of the above-described problems, and can provide a solar cell, a solar cell module, and a solar cell that can satisfactorily join a conductive wire and a bus bar electrode and can reduce manufacturing costs. It aims at providing the manufacturing method of.

  In order to achieve the above object, a solar cell according to the present invention is formed on a battery body having a surface as a light receiving surface and a back surface back to back on the surface, a surface electrode formed on the surface, and the back surface. A first island-shaped electrode; a second island-shaped electrode provided on the back surface along the first direction at a predetermined interval; and a second island-shaped electrode provided on the back surface. And a back electrode layer provided so as to cover the back surface including the first island electrode and the second island electrode, and the first island electrode and the second island are provided on the back electrode layer. An opening exposing a part of the electrode is provided.

  A solar cell module using a solar cell according to the present invention includes a first plate-like member and a second plate-like member which are arranged to face each other, a front surface as a light receiving surface, and a back surface back to back. A plurality of island-shaped electrodes provided on the back surface at a predetermined interval along the first direction, and a plurality of island-shaped electrodes on the back surface. A back electrode layer provided so as to cover the back surface including the island-shaped electrode, and an opening exposing at least one part of the plurality of island-shaped electrodes is provided in the back electrode layer. A plurality of solar cells arranged in a matrix between the first plate-like member and the second plate-like member, and one of the island-like electrodes in the adjacent solar cells A strip-shaped lead wire electrically connected to the other surface electrode, and at least one package surrounding the solar cell and disposed between the first plate-like member and the second plate-like member And a member.

  A solar cell according to the present invention includes a step of preparing a battery body having a surface as a light receiving surface and a back-to-back surface on the surface, a step of forming a surface electrode on the surface, and a first surface on the back surface in a first direction. A plurality of island-shaped electrodes arranged at a predetermined interval along the back surface, and a back electrode layer covering the back surface including the plurality of island-shaped electrodes, and at least one of the plurality of island-shaped electrodes formed on the back electrode layer And a step of providing an opening exposing one part, and the back electrode layer is formed after the island-shaped electrode is formed.

  According to the solar cell of the present invention, since the opening that exposes both ends of the island-shaped electrode in the first direction is formed in the back electrode layer, both ends of the island-shaped electrode in the first direction are the back electrode. Not covered by a layer. Therefore, a sufficient welding area can be ensured by the conducting wire, so that the welding strength can be improved and, as a result, the product reliability can be improved.

It is a partial cross section figure which shows the structure of 1st Embodiment of the solar cell module which concerns on this invention. It is a bottom view of the solar cell which concerns on 1st Embodiment. It is a figure which expands and shows a part of FIG. It is sectional drawing of line BB in FIG. It is sectional drawing of line CC in FIG. It is a flowchart which shows the manufacturing method of the solar cell which concerns on 1st Embodiment. It is a bottom view which shows the structure of 2nd Embodiment of the solar cell module which concerns on this invention. It is a figure which expands and shows a part of FIG. It is a bottom view which expands and shows a part of structure of 3rd Embodiment of the solar cell module which concerns on this invention. It is a bottom view which expands and shows a part of structure of 4th Embodiment of the solar cell module which concerns on this invention. It is a bottom view which expands and shows a part of structure of 5th Embodiment of the solar cell module which concerns on this invention. It is a bottom view which shows the structure of 6th Embodiment of the solar cell module which concerns on this invention. It is a bottom view which expands and shows a part of structure of 7th Embodiment of the solar cell module which concerns on this invention. It is a bottom view which expands and shows a part of structure of 8th Embodiment of the solar cell module which concerns on this invention. It is a bottom view which shows an example of the conventional solar cell module. It is a partial cross section figure which shows an example of the conventional solar cell module.

  Hereinafter, the present invention will be described based on some preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

(First embodiment)
FIG. 1 is a partial cross-sectional view showing a configuration of a first embodiment of a solar cell module according to the present invention. As shown in the figure, this solar cell module includes a first plate-like member 1 and a second plate-like member 2 which are arranged to face each other vertically, and a first plate-like member 1 and a second plate-like member. A plurality of solar cells 3 arranged in a matrix between 2, a strip-shaped lead wire (ribbon) 4 electrically connecting adjacent solar cells 3, and surrounding the solar cell 3 and And at least one package member 5 disposed between one plate-like member 1 and the second plate-like member 2.

  As the first plate-like member 1 and the second plate-like member 2, glass or plastic plates can be used, but are not particularly limited. In addition, as a plate-shaped member as the light-receiving surface side of a battery, what has a light transmittance is required. The conducting wire 4 electrically connects the surface of the solar cell 3 and the back surface of another adjacent solar cell 3 to form a pair of two solar cells 3. For the package member 5, for example, a material such as an ethylene vinyl acetate (EVA) copolymer having optical transparency can be appropriately used, but there is no particular limitation.

  As shown in FIGS. 2 to 5, the solar cell 3 includes a battery body 31, a surface electrode 32, a plurality of first island electrodes 33, and a back electrode layer 34.

  The battery body 31 is formed on the front side of the surface 312, a substrate 311 having a surface 312 as a light receiving surface and a back surface 313 back to back to the surface 312, an emitter layer 314 disposed on the back side of the substrate 311 near the surface 312. And an antireflection layer 315. As the substrate 311, for example, a silicon substrate can be used. The battery body 31 has a structure in which one of the substrate 311 and the emitter layer 314 is an n-type semiconductor and the other is a p-type semiconductor, and an n-type semiconductor and a p-type semiconductor are joined. The antireflection layer 315 uses, for example, a silicon nitride (SiNx) compound in order to suppress light reflection and increase the amount of incident light.

  The surface electrode 32 is provided on the surface 312 through the antireflection layer 315 on the front side of the surface 312 as the light receiving surface of the battery body 31. Since the arrangement of the surface electrode 32 is a known technique in the technical field, details thereof are omitted here.

  The plurality of first island electrodes 33 are arranged in two rows on the back surface 313, and the plurality of first island electrodes 33 in the same row arranged in the first direction 61 are used as the bus bar electrodes 330. In total, two rows are formed at predetermined intervals in a second direction 62 that is perpendicular to the first direction 61.

  The first island electrode 33 preferably has a minimum length a1 along the first direction 61 larger than a minimum width a2 along the second direction 62. As an example, the first island electrode 33 includes: It is formed in a rectangular shape having a longitudinal direction in the first direction 61. The “island electrode” in the present invention means that these first island electrodes 33 are arranged at intervals, and the shape is not limited, and is rectangular, circular, It may be a semicircular shape, an elliptical shape, a multi-sided shape, or the like.

  The back electrode layer 34 includes a plurality of first island electrodes 33 and is disposed so as to cover the back surface 313, and the first island electrodes 33 correspond to the first island electrodes 33. Both ends of the direction 61 are open, and an opening 340 in which a part of the first island electrode 33 is exposed is provided. The opening 340 is provided so as to have a one-to-one correspondence with the first island electrode 33.

  The minimum length a1 along the first direction 61 of the first island-shaped electrode 33 is smaller than the minimum length b1 along the first direction 61 of the opening 340, and the second length of the first island-shaped electrode 33 is The minimum width a2 along the direction 62 is greater than the minimum width b2 along the second direction 62 of the opening 340. The first island electrode 33 and the back electrode layer 34 have a difference between a2 and b2 (twice that of d2 in FIG. 3) of 0.1 mm to 1.2 mm in consideration of processing accuracy by screen printing. It is preferable to fit.

  More specifically, the first island-shaped electrode 33 includes the first electrode body 331 exposed by the opening 340 and the second direction 62 from both sides of the second direction 62 of the first electrode body 331. And two first electrode extending portions 332 extending along the line. The shapes of the two first electrode extending portions 332 may be the same or different. In this embodiment, the two first electrode extending portions 332 are formed to extend from both sides of the first electrode main body portion 331 while being covered with the back electrode layer 34. As shown in FIG. 3, d <b> 2 corresponds to the minimum width along the second direction 62 of the first electrode extending portion 332.

  The opening 340 includes an opening main body 341 exposing the first electrode main body 331 and two openings extending along the first direction 61 subsequent to both ends of the opening main body 341 in the first direction 61. It has the extended part 342, and the outline of the two opening extended parts 342 may be the same or different. In this embodiment, the minimum length d1 along the first direction 61 of the opening extension 342 is preferably 0 mm <d1 ≦ 0.4 mm.

  Each of the plurality of first island electrodes 33 is welded to the corresponding conductor 4 of the solar cell 3 by each bus bar electrode 330. The solar cells 3 are connected in series by connecting one first island-shaped electrode 33 and the other surface electrode 32 of the adjacent solar cells 3 to each other by the corresponding conductive wire 4.

  In this embodiment, d1 is d1> 0 as described above, and the opening 340 is provided as b1 = a1 + d1, so b1 is larger than a1, that is, the opening 340 is the first island-shaped electrode 33. It is formed so as to extend longer than the length along the first direction 61. As a result, both ends of the first island-shaped electrode 33 in the first direction 61 are not covered with the back electrode layer 34, and thus can be in good contact with the conductive wire 4. Therefore, it can weld favorably and can obtain the outstanding joint strength. In this embodiment, when FIG. 5 is compared with FIG. 16, it can be seen that the gap 930 in FIG. 16 can be reduced or eventually eliminated.

  On the other hand, when d1 exceeds 0.4 mm, good bonding strength cannot be obtained. Therefore, d1 along the first direction 61, which is the length of the portion longer than the first island electrode 33 of the opening 340, is It is preferably larger than 0 mm and not larger than 0.4 mm.

  Considering the processing accuracy of screen printing, it is preferable that the minimum width d2 along the second direction 62 of the first electrode extending portion 332 is 0.3 mm or more. In this case, the back electrode layer 34 covers both sides of the first island-like electrode 33 in the second direction 62, so that the back electrode layer 34 is electrically connected to the plurality of first island-like electrodes 33. Can be done.

  Here, in the opening 340, one opening extending portion 342 and the other opening extending portion 342 may have the same or different minimum length d1. In the first island-shaped electrode 33, one first electrode extending portion 332 and the other first electrode extending portion 332 may have the same or different minimum width d2. In this embodiment, it is noted that the minimum length (width) is the minimum length (width) because each component cannot be made to have a uniform length or width when the components are irregularly shaped. I want.

  In this embodiment, the opening 340 may be formed so as to expose a part of the first island electrode 33, and the number thereof is not limited.

  Next, a first embodiment of a method for manufacturing a solar cell having the above configuration will be described with reference to FIG.

  In step S71, a substrate 311 having a front surface 312 as a light receiving surface and a back surface 313 back to back is formed, an emitter layer 314 disposed on the back side of the substrate 311 near the front surface 312 and a front surface of the surface 312. A battery body 31 having an antireflection layer 315 is prepared. The emitter layer is formed by a diffusion manufacturing process, and the antireflection layer 315 is formed by vacuum deposition or the like. The vacuum vapor deposition here includes physical vapor deposition (PVD), chemical vapor deposition (CVD) and the like, and the chemical vapor deposition is plasma enhanced chemical vapor deposition (PECVD) and the like.

  In step S72, the surface electrode 32 is formed on the front side of the surface 312 as the light receiving surface. For example, a conductive paste is applied to cover the surface 312 by screen printing or the like, and the conductive paste erodes the antireflection layer 315 and penetrates the emitter layer 314 by high temperature sintering. Then, the conductive paste is cured and the surface electrode 32 is formed.

  In step S <b> 73, the first island electrode 33 and the back electrode layer 34 provided so as to cover the back surface 313 including the first island electrode 33 are formed on the back surface 313, and An opening 340 for exposing a part of the first island electrode 33 is provided. In step S73, the first island electrode 33 is first formed on the back surface 313, and then the back electrode layer 34 is formed. For example, a conductive paste such as silver is applied so as to cover the back surface 313 by screen printing or the like, and the conductive paste is cured by sintering to form the first island-shaped electrode 33. Further, a conductive paste such as aluminum is applied by screen printing or the like, and the back electrode layer 34 is formed by high-temperature sintering. Step S73 may be performed before step S72.

  In this embodiment, the opening 340 is formed so as to expose both ends of the first island-shaped electrode 33 in the first direction 61. Thereby, the welding area by the conducting wire 4 is ensured, and the reliability of a product can be improved. In addition, the bus bar electrode 330 is not formed as a band-shaped bus bar electrode as in the prior art, but is formed by a plurality of first island-shaped electrodes 33 provided in a line at intervals from each other. The amount of conductive paste used is small. Therefore, the manufacturing cost can be reduced.

(Second Embodiment)
FIG. 7 is a bottom view showing the configuration of the second embodiment of the solar cell module according to the present invention, and FIG. 8 is an enlarged view showing a part thereof.

  In the second embodiment, the difference from the first embodiment is that the second island electrodes 35 are further arranged adjacent to the first island electrodes 33, and the back electrode layer 34 is An opening 340 having a predetermined shape is formed so that a part of the island-shaped electrodes arranged side by side is exposed.

  In the second embodiment, two rows of bus bar electrodes 330 extending in a strip shape along the first direction 61 are provided on the back surface side of the solar cell 3, and the bus bar electrodes 330 are spaced apart from each other by a predetermined distance. Adjacent to the plurality of first island-shaped electrodes 33 arranged in a row and the first island-shaped electrode 33 sandwiched and sandwiched between the first island-shaped electrodes 33 at a predetermined interval from each other. And a plurality of second island-like electrodes 35 provided so as to be arranged in the same row. Adjacent first island-shaped electrodes 33 and second island-shaped electrodes 35 are provided as one electrode set 350 alternately arranged in the same row at a predetermined interval.

  In the back electrode layer 34, a plurality of openings 340 are formed at predetermined intervals corresponding to the plurality of electrode sets 350. Both ends of the electrode set 350 in the first direction 61 are exposed by the openings 340, and both sides of the electrode set 350 in the second direction 62 are covered by the back electrode layer 34.

  More specifically, the first island-shaped electrode 33 includes a first electrode main body 331 exposed by the opening 340 and a second electrode 62 from both sides of the first electrode main body 331 in the second direction 62. And two first electrode extension portions 332 extended along the direction 62. The two first electrode extending portions 332 are covered with the back electrode layer 34, and each may have the same or different outline. The second island-shaped electrode 35 is extended along the second direction 62 from both sides of the second electrode main body 351 opened by the opening 340 and the second direction 62 of the second electrode main body 351. And two second electrode extending portions 352. The two second electrode extending portions 352 are covered with the back electrode layer 34, and each may have the same or different outline.

  The opening 340 includes a first opening main body 343 and a second opening main body 344 that expose the first electrode main body 331 and the second electrode main body 351, and the first island-shaped electrode 33. Two first opening extending portions 345 formed longer than the first opening main body portion 343 so as to expose both end portions in the direction 61, and both ends in the first direction 61 of the second island-shaped electrode 35 Two second opening extension portions 346 formed to be longer than the second opening main body portion so as to expose the portion, and adjacent first opening extension portions 345 and second opening extension portions in the electrode set 350 And a connecting portion 347 to which the 346 is connected. In this embodiment, as shown in FIG. 8, the connecting portion 347 connects the first opening extension portion 345 and the second opening extension portion 346, and It is bent inward in the first direction 61 so as to be smaller than the minimum width b2 along the second direction 62 with the second opening extension 346, and is formed in a pincushion neck shape.

  Note that the outlines of the two first opening extending portions 345 may be the same or different. The outlines of the two second opening extending portions 346 may be the same or different. The outlines of the first opening extension 345 and the second opening extension 346 may be the same or different.

  The minimum length d3 along the first direction 61 of each first opening extension 345 may be the same as or different from each other, and is preferably 0 mm <d3 ≦ 0.4 mm. The minimum length d4 along the first direction 61 of each second opening extension 346 may be the same as or different from each other, and is preferably 0 mm <d4 ≦ 0.4 mm.

  Both the minimum width a2 along the second direction 62 of the first island electrode 33 and the minimum width c2 along the second direction 62 of the second island electrode 35 are both the first opening body 343. The second opening main body 344 is larger than the minimum width b2 along the second direction 62, and the difference between a2 and b2 and the difference between c2 and b2 are both 0.1 mm to 1.2 mm. preferable.

  As an example, the minimum width d2 along the second direction 62 of the first electrode extension 332 and the minimum width d5 along the second direction 62 of the second electrode extension 352 may both be greater than 0.3 mm. preferable. The minimum width d2 of the first electrode extending portion 332 on both sides of the first island electrode 33 may be the same or different, and the second electrode extending portion 352 on both sides of the second island electrode 35 may be different. The minimum width d5 may be the same or different, and d2 and d5 may be the same or different.

  In the solar cell according to this embodiment, the first island-shaped electrode 33 and the second island-shaped electrode 35 may be the same or different in structure. Here, in the solar cell module, it is necessary to connect the first island-shaped battery 33 and the second island-shaped battery 35 of one battery and the surface electrodes of the other battery with conductive wires in adjacent solar cells 3. Please note that.

  In this embodiment, the connection portion 347 is formed in a neck shape with a smaller diameter than the two second opening extension portions 346, so that the conductive area of the back electrode layer 34 can be increased, and the current concentration efficiency can be increased. Can be improved.

  Since the manufacturing method of the solar cell according to this embodiment is the same as the manufacturing method of the solar cell according to the first embodiment, detailed description thereof is omitted.

  As described above, in this embodiment, similarly to the first embodiment, it is possible to sufficiently secure the welding area by the conductive wire 4 to improve the reliability of the product, and to reduce the usage amount of the conductive paste. This also has the effect of reducing the manufacturing cost.

(Third embodiment)
FIG. 9 is an enlarged bottom view showing a part of the configuration of the solar cell module according to the third embodiment.

  In the solar cell module according to the third embodiment, the difference from the second embodiment is that the neck-shaped connection part 347 is not formed, and the first opening extension part 345 and the second opening extension part 346 are different. The opening 340 is formed so as to be connected and have the same width along the second direction 62 over the first direction 61.

  The first island electrode 33 and the second island electrode 35 are such that the minimum widths a2 and c2 along the second direction 62 are larger than the minimum width b2 along the second direction 62 of the opening 340. Is provided. The difference between a2 and b2 and the difference between c2 and b2 are both preferably 0.1 mm to 1.2 mm.

  Since the manufacturing method of the solar cell according to the third embodiment is the same as the manufacturing method of the solar cell according to the first embodiment, detailed description thereof is omitted.

  Also in this embodiment, as in the above-described embodiment, a sufficient welding area can be secured by the conducting wire 4 to improve the reliability of the product, the amount of conductive paste used can be reduced, and the manufacturing cost can be reduced. It also has an effect that can be.

(Fourth embodiment)

  FIG. 10 is an enlarged bottom view showing a part of the configuration of the fourth embodiment of the solar cell module according to the present invention. As shown in the drawing, the fourth embodiment has a second opening except that an opening 340 having a connecting portion 347 extending from the first opening extending portion 345 to the second opening extending portion 346 is formed. This is almost the same as the embodiment.

  The connecting portion 347 is formed in a neck shape with a first opening extending portion 345 and a second opening extending portion 346 in the shape of a work in plan view, and is the outermost portion along the second direction 62 of the connecting portion 347. The small width is smaller than the minimum width along the second direction 62 of the first opening main body 343 and the second opening main body 344.

(Fifth embodiment)
FIG. 11: is a bottom view which expands and shows a part of structure of 5th Embodiment of the solar cell module which concerns on this invention. As shown in the figure, the connecting portion 347 is formed in an approximately S shape in plan view from the first island-shaped electrode 33 to the second island-shaped electrode 35, and extends along the second direction 62 of the connecting portion 347. Is provided to be smaller than the minimum width along the second direction 62 of the first opening main body 343 and the second opening main body 344.

(Sixth embodiment)
FIG. 12 is a bottom view showing the configuration of the sixth embodiment of the solar cell module according to the present invention.

  In the sixth embodiment, the bus bar electrodes 330 are arranged in two rows along the first direction 61, and each bus bar electrode 330 includes one first island electrode 33 and the first island electrode. 33, one second island-shaped electrode 35 arranged in the first direction 61 with a predetermined interval and N arranged in the first direction 61 with a predetermined interval from the second island-shaped electrode 35 (however, , N ≧ 1) third island-shaped electrodes 36. The back electrode layer 34 is provided with an opening 340 extending from the first island electrode 33 to the third island electrode 36 corresponding to each bus bar electrode 330. Each opening 340 extends along the first direction 61 corresponding to the bus bar electrode 330, and the first island electrode 33, the second island electrode 35, and the like in the corresponding bus bar electrode 330 through the opening 340 A part of each of the N third island electrodes 36 is exposed, and the other part of each of the first island electrodes 33, the second island electrodes 35, and the N third island electrodes 36. Is covered with a back electrode layer 34.

  Thus, by forming one opening 340 for each bus bar electrode 330, both ends of the island-shaped electrodes 33, 35, and 36 in the first direction 61 are not covered by the back electrode layer 34, which is sufficient. A large welding area can be secured, and the bonding strength can be improved. In addition, since one opening 340 is formed for each bus bar electrode 330, manufacturing is also simplified.

  The structures of the first island-shaped electrode 33, the second island-shaped electrode 35, and the third island-shaped electrode 36 may be the same or different. Since the manufacturing method according to this embodiment is substantially the same as the manufacturing method according to the first embodiment, detailed description thereof is omitted.

  In addition, although the opening 340 is formed in a rectangular shape in the sixth embodiment, the outline of the portion at the boundary between adjacent island electrodes is formed as in the second, fourth, and fifth embodiments. Also good.

(Seventh embodiment)
FIG. 13: is a bottom view which expands and shows a part of structure of 7th Embodiment of the solar cell module which concerns on this invention. In the seventh embodiment, an opening 340 having an opening main body 341 that exposes a part of each island-shaped electrode and an opening extending portion 342 that exposes both ends of the island-shaped electrode 61 in the first direction 61 is provided. ing. Each opening extending portion 342 is formed with a protruding portion 348 that is further extended outward along the first direction 61 on the side opposite to the opening main body portion 341.

  In this embodiment, the protrusion 348 is formed in a triangular shape that is pointed along the first direction 61. The opening 340 is formed so that the adjacent protrusions 348 are not communicated with each other, but may be formed so that the adjacent protrusions 348 are communicated as in the sixth embodiment.

(Eighth embodiment)
FIG. 14 is an enlarged bottom view showing a part of the configuration of the eighth embodiment of the solar cell module according to the present invention. This embodiment is substantially the same as the seventh embodiment, but the protrusion 348 protrudes in an arc shape.

  The embodiment described above is intended to clarify the technical contents of the present invention, and the present invention is not limited to such specific examples and is not interpreted in a narrow sense. Various modifications can be made within the scope of the spirit of the invention and the claims.

DESCRIPTION OF SYMBOLS 1 1st plate-shaped member 2 2nd plate-shaped member 3 Solar cell 31 Battery main body 311 Board | substrate 312 Surface (light-receiving surface)
313 Back surface 314 Emitter layer 315 Antireflection layer 32 Front surface electrode 33 First island electrode 330 Bus bar electrode 331 First electrode main body portion 332 First electrode extending portion 34 Back electrode layer 340 Opening 341 Opening main body portion 342 Opening extending portion 343 First opening main body portion 344 Second opening main body portion 345 First opening extending portion 346 Second opening extending portion 347 Connection portion 348 Projection portion 35 Second island electrode 350 Electrode set 351 Second electrode main body Part 352 Second electrode extending part 36 Third island electrode 4 Conductive wire 5 Package member 61, 62 Direction S71 to S73 Steps a1, b1, d1, d3, d4 Lengths a2, b2, c2, d2, d5 Width

Claims (16)

A battery body having a surface as a light-receiving surface and a back-to-back surface on the surface;
A surface electrode formed on the surface;
A first island electrode formed on the back surface;
A second island-like electrode provided on the back surface along the first direction at a predetermined interval from the first island-like electrode;
A back electrode layer provided to cover the back surface including the first island electrode and the second island electrode on the back surface;
The solar cell, wherein the back electrode layer is provided with an opening exposing a part of the first island-like electrode and the second island-like electrode.   The minimum width along the second direction perpendicular to the first direction of the first island-shaped electrode and the second island-shaped electrode is larger than the minimum width along the second direction of the opening. The solar cell according to claim 1. The first island-shaped electrode has a first electrode main body exposed by the opening,
The second island-shaped electrode has a second electrode main body exposed by the opening,
The opening includes a first opening main body part exposing the first electrode main body part, a second opening main body part exposing the second electrode main body part, and the first opening main body part. Two first opening extension portions extended along the first direction from both ends of the first direction, and the first direction from both ends of the second opening main body portion in the first direction. And a second opening extending portion extending along the first opening extending portion and the second opening extending portion adjacent to the first opening extending portion are connected to each other. And
The minimum width along the second direction perpendicular to the first direction of the connection portion is smaller than the minimum width along the second direction of the first opening body portion and the second opening body portion. The solar cell according to claim 1.   4. The sun according to claim 3, wherein a minimum length along the first direction of the first opening extension portion and the second opening extension portion is greater than 0 mm and not more than 0.4 mm. battery. The first island-shaped electrode further includes two first electrode extending portions extending along the second direction from both sides of the first electrode main body portion in the second direction,
The second island-like electrode further includes two second electrode extending portions extending along the second direction from both sides in the second direction of the second electrode main body. The solar cell according to claim 4. The difference between the minimum width along the second direction perpendicular to the first direction of the first island electrode and the minimum width along the second direction of the opening is 0.1 mm to 1.2 mm. Yes,
The difference between the minimum width along the second direction of the second island electrode and the minimum width along the second direction of the opening is 0.1 mm to 1.2 mm. Item 2. The solar cell according to Item 1. Further, the third electrode is covered with the back electrode layer on the back surface, and is arranged in a row along the first direction so as to be separated from the first island electrode and the second island electrode. An island electrode is provided, where N is 1 or an integer of 1 or more;
The opening that exposes a part of the first island-like electrode, the second island-like electrode, and the N third island-like electrodes is formed in the back electrode layer. The solar cell according to claim 1. A first plate-like member and a second plate-like member which are arranged opposite to each other;
The plurality of solar cells according to any one of claims 1 to 6, which are arranged in a matrix between the first plate-like member and the second plate-like member,
A strip-shaped lead wire that electrically connects one of the first island-shaped electrodes and one of the second island-shaped electrodes in the adjacent solar cells to the other surface electrode;
A solar cell module comprising: at least one package member surrounding the solar cell and disposed between the first plate-like member and the second plate-like member. A first plate-like member and a second plate-like member which are arranged opposite to each other;
The plurality of solar cells according to claim 7, which are arranged in a matrix between the first plate-like member and the second plate-like member,
One of the first island-shaped electrodes, one of the second island-shaped electrodes, and one of the third island-shaped electrodes in the adjacent solar cells are electrically connected to the other surface electrode. Lead wires,
A solar cell module comprising: at least one package member surrounding the solar cell and disposed between the first plate-like member and the second plate-like member. Preparing a battery body having a front surface as a light receiving surface and a back-to-back surface on the surface;
Forming a surface electrode on the surface;
A first island-shaped electrode on the back surface; a second island-shaped electrode aligned with the first island-shaped electrode along the first direction at a predetermined interval; and the first island-shaped electrode, Forming a back electrode layer covering the back surface including the second island electrode, and opening the first electrode and a part of the second island electrode exposed on the back electrode layer; Providing a step,
The back electrode layer is formed after forming the first island-shaped electrode and the second island-shaped electrode.   The minimum width along the second direction perpendicular to the first direction of the first island-shaped electrode and the second island-shaped electrode is larger than the minimum width along the second direction of the opening. The method for manufacturing a solar cell according to claim 10. The first island-shaped electrode has a first electrode main body exposed by the opening,
The second island-shaped electrode has a second electrode main body exposed by the opening,
The opening includes a first opening main body part exposing the first electrode main body part, a second opening main body part exposing the second electrode main body part, and the first opening main body part. Two first opening extension portions extended along the first direction from both ends of the first direction, and the first direction from both ends of the second opening main body portion in the first direction. And a second opening extending portion extending along the first opening extending portion and the second opening extending portion adjacent to the first opening extending portion are connected to each other. And
The minimum width along the second direction perpendicular to the first direction of the connection portion is smaller than the minimum width along the second direction of the first opening body portion and the second opening body portion. The method for manufacturing a solar cell according to claim 10.   13. The sun according to claim 12, wherein a minimum length along the first direction of the first opening extension portion and the second opening extension portion is greater than 0 mm and not more than 0.4 mm. Battery manufacturing method. The first island-like electrode further includes two first electrode extending portions extending along the second direction from both ends in the second direction of the first electrode main body,
The second island-like electrode further includes two second electrode extending portions extending along the second direction from both ends of the second electrode main body in the second direction. The method for producing a solar cell according to claim 13. The difference between the minimum width along the second direction perpendicular to the first direction of the first island electrode and the minimum width along the second direction of the opening is 0.1 mm to 1.2 mm. Yes,
The difference between the minimum width along the second direction of the second island electrode and the minimum width along the second direction of the opening is 0.1 mm to 1.2 mm. Item 11. A method for producing a solar cell according to Item 10. In addition, N (where N ≧ 1) third islands are arranged on the back surface of the battery body and spaced apart from the first island-like electrode and the second island-like electrode along the first direction. Island electrodes are placed,
The back electrode layer is provided so that a part of the first island electrode, the second island electrode, and the N third island electrodes are exposed through the opening. The method for manufacturing a solar cell according to claim 10.

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