JP2012119365A - Solar battery module and method for manufacturing solar battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve favorable connection reliability by using a tab line with an adhesive layer formed preliminary on one surface thereof, in a solar battery module.SOLUTION: A solar battery module includes: a plurality of solar battery cells 2, each of which has electrodes 11, 13 formed on front and back surfaces thereof; and a tab line 3 having an adhesive layer 17 provided on one surface of a conductive base material 16 and connecting each solar battery cell 2 by being connected to the front surface electrode 11 and the back surface electrode 13 of each solar battery cell 2 via the adhesive layer 17. In the tab line 3, one surface on which the adhesive layer 17 is provided is inverted between the solar battery cells 2 adjacent with each other, and connected to the front surface electrode 11 of each solar battery cell 2 and the back surface electrode 13 of an adjacent solar battery cell.

Description

  The present invention relates to a solar cell module in which electrodes of a plurality of solar cells are connected by tab wires, and a method for manufacturing the solar cell module.

  In the crystalline silicon solar cell module, a plurality of adjacent solar cells are connected by tab wires made of a ribbon-like copper foil or the like coated with solder as an interconnector. One end side of the tab wire is connected to the front surface electrode of one solar battery cell, and the other end side is connected to the back surface electrode of the adjacent solar battery cell, thereby connecting the solar battery cells in series. At this time, the tab wire is bonded to the surface electrode of one solar battery cell on one surface side of one end side, and to the back electrode of the adjacent solar battery cell on the other surface side of the other end side.

  Specifically, the connection between the solar battery cell and the tab wire is made up of a bus bar electrode formed by screen printing of silver paste on the light receiving surface of the solar battery cell, an Ag electrode formed on the back surface connection portion of the solar battery cell, and a tab. The wires are connected by soldering (Patent Document 1). In addition, Al electrodes and Ag electrodes are formed in regions other than the connection portion on the back surface of the solar battery cell.

  However, since soldering is performed at a high temperature of about 260 ° C., the solar cells are warped, the internal stress generated at the connection between the tab wire and the front and back electrodes, the residue of the flux, etc. There is a concern that the connection reliability between the front and back electrodes of the battery cell and the tab wire is lowered.

  Therefore, conventionally, a conductive adhesive film that can be connected by thermocompression treatment at a relatively low temperature is used for connection between the front and back electrodes of the solar battery cell and the tab wire (Patent Document 2). As such a conductive adhesive film, a film obtained by dispersing spherical or scaly conductive particles having an average particle size on the order of several μm in a thermosetting binder resin composition is used.

  The conductive adhesive film is interposed between the front electrode and the back electrode and the tab wire, and then thermally pressed from above the tab wire, so that the binder resin exhibits fluidity and between the electrode and the tab wire. As it flows out, the conductive particles conduct between the electrode and the tab wire, and in this state, the binder resin is thermally cured. Thereby, the string by which the several photovoltaic cell was connected in series by the tab wire is formed.

  A plurality of solar cells in which a tab wire and a front electrode and a back electrode are connected using a conductive adhesive film are made of a surface protective material having translucency such as glass and translucent plastic, and PET (Poly Ethylene Terephthalate). ) And the like, and a back protective material made of a film such as ethylene vinyl acetate resin (EVA).

JP 2004-356349 A JP 2008-135654 A JP 2008-294383 A

  By the way, in the manufacturing process of the solar cell module using the conductive adhesive film, the conductive adhesive film is temporarily pasted in advance at predetermined positions on the surface electrode and the back electrode of the solar battery cell, and then the conductive adhesion is performed. The tab wire is temporarily arranged on the film, and the conductive adhesive film is cured by heating and pressing the tab wire. Thus, in the conventional construction method, many man-hours, such as temporary sticking of an electroconductive adhesive film, temporary arrangement | positioning of a tab wire | line, the thermal pressurization of a tab wire | line, are required.

  Therefore, in recent years, a method has been proposed in which a tab wire on which an adhesive layer is formed in advance is used, and the tab wire with the adhesive layer is directly adhered to predetermined positions on the front surface electrode and the back surface electrode of the solar battery cell.

  However, in the construction method, since the adhesive layer is formed on only one surface of the tab line that is defined in advance, the one surface and the other surface cannot be adhered to each electrode of the adjacent solar battery cell as it is. In addition, if an adhesive layer is formed on one side and the other side of the tab wire, it is possible to adhere to the front electrode and the back electrode of the adjacent solar battery cell, but it is uneconomical to form an unused adhesive layer. In addition, since the adhesive layer is exposed, there is a concern about adhesion or outflow of the adhesive composition to other components.

  Moreover, although the construction method which adheres the tab wire with an adhesive layer to the front electrode and the back electrode by twisting between adjacent solar cells (see Patent Document 3), the stress caused by twisting the tab wire is a solar cell. It is transmitted to the connection part with each electrode of the cell, and there is a concern about peeling from the electrode of the tab wire. Further, in the solar battery cell, the tab wire has been thinned to reduce the shadow loss, so that twisting may cause disconnection, deterioration, high resistance, and the like, resulting in poor connection reliability.

  Accordingly, the present invention provides a solar cell module capable of achieving connection with good connection reliability while using a tab wire with an adhesive layer in which an adhesive layer is formed on one surface in advance, and a method for manufacturing the solar cell module The purpose is to do.

  In order to solve the above-described problems, a solar cell module according to the present invention includes a plurality of solar cells having electrodes formed on the front and back surfaces, and an adhesive layer provided on one surface of the conductive substrate. Via a tab wire that connects each of the solar cells by being connected to the surface electrode and the back electrode of the solar cell, and the tab layer has the adhesive layer between the adjacent solar cells. One surface provided is inverted and connected to the surface electrode of the solar cell and the back electrode of the adjacent solar cell.

  In addition, the method for manufacturing a solar cell module according to the present invention includes a step of arranging a plurality of solar cells having electrodes formed on the front and back sides, a solar cell in which an adhesive layer is provided on one surface and the one surface is adjacent. The one surface on one end side of the tab line inverted between is temporarily arranged on the surface electrode of one solar cell, and the one surface on the other end side of the tab line is temporarily arranged on the back electrode of the other solar cell. The step and the other side of the tab wire opposite to the one surface are heated and pressed to connect the front surface electrode and the back surface electrode to the tab wire, and the solar cells adjacent via the tab wire Connecting.

  According to the present invention, the tab wire is connected to the surface electrode of the solar battery cell and the back electrode of the adjacent solar battery cell, with one surface provided with the adhesive layer reversed. Therefore, a solar cell module can be formed using a tab wire having an adhesive layer provided on one side in advance, the number of parts and work man-hours can be reduced, and productivity is improved while ensuring good connection reliability. be able to.

It is a disassembled perspective view which shows a solar cell module. It is sectional drawing which shows the string of a photovoltaic cell. It is a top view which shows two photovoltaic cells connected by the tab line from the light-receiving surface side. It is a figure which shows the difference in the manufacturing process of this invention and the conventional invention. It is a figure which shows an original fabric film. It is a figure which shows the conventional solar cell module in which a defective photovoltaic cell interposes. It is a figure which shows the conventional solar cell module which isolate | separates a defective photovoltaic cell by connecting a tab wire. It is a figure which shows the conventional solar cell module which has arrange | positioned the normal photovoltaic cell. It is a figure which shows the conventional solar cell module which connected the normal photovoltaic cell and the existing photovoltaic cell with the auxiliary tab line. It is a figure which shows the solar cell module in which a defective photovoltaic cell interposes. It is a figure which shows the solar cell module which cuts off a defective photovoltaic cell by connecting a tab wire. It is a figure which shows the solar cell module which has arrange | positioned the normal photovoltaic cell. It is a figure which shows the solar cell module which connected the normal photovoltaic cell and the existing photovoltaic cell with the auxiliary tab line. It is a perspective view which shows the other structure of a tab line. It is a top view which shows the distance of the finger electrode which the tab wire in the conventional photovoltaic cell collects electricity. It is a top view which shows the distance of the finger electrode which the tab wire collects in the photovoltaic cell using the tab wire which formed the 1st connecting piece stuck on the light-receiving surface side of a photovoltaic cell. It is a perspective view which shows the other structure of a tab line. It is a figure for demonstrating the temporary arrangement | positioning process of a tab line. It is a figure for demonstrating the heating-pressing process of a tab wire. It is a side view which shows the structure which clamps the outer edge part of a photovoltaic cell by a folding | turning part. It is a perspective view which shows the tab line which has the uneven | corrugated | grooved part by which the peak part and trough part which continue on the surface over a longitudinal direction were formed alternately in the width direction. It is sectional drawing which shows the solar cell module to which the tab wire in which the uneven | corrugated | grooved part was formed was connected. It is sectional drawing which shows the shape of an uneven | corrugated | grooved part. It is sectional drawing which shows the conventional solar cell module to which the tab wire in which the uneven | corrugated | grooved part was formed was connected. It is a top view which shows the solar cell module which varied the width | variety of the 1st, 2nd connection piece. It is a figure for demonstrating the structure of a general silicon-type solar cell. It is a side view for demonstrating the curvature of a general silicon type photovoltaic cell.

  Hereinafter, a solar cell module to which the present invention is applied and a method for manufacturing the solar cell module will be described in detail with reference to the drawings.

[Solar cell module]
The solar cell module 1 to which the present invention is applied has a string 4 in which a plurality of solar cells 2 are connected in series by a tab wire 3 serving as an interconnector, as shown in FIGS. A matrix 5 in which a plurality of 4 are arranged is provided. And the solar cell module 1 is laminated together with the front cover 7 provided on the light receiving surface side and the back sheet 8 provided on the back surface side, with the matrix 5 sandwiched between the sealing adhesive sheets 6. Finally, a metal frame 9 such as aluminum is attached to the periphery.

  As the sealing adhesive, for example, a translucent sealing material such as ethylene vinyl acetate resin (EVA) is used. Moreover, as the surface cover 7, for example, a light-transmitting material such as glass or light-transmitting plastic is used. Further, as the back sheet 8, a laminated body in which glass or aluminum foil is sandwiched between resin films is used.

  Each solar battery cell 2 of the solar battery module has a photoelectric conversion element 10. The photoelectric conversion element 10 is a single crystal silicon photoelectric conversion element, a crystalline silicon solar cell using a polycrystalline photoelectric conversion element, a cell made of amorphous silicon and a cell made of microcrystalline silicon or amorphous silicon germanium. Various photoelectric conversion elements 10 such as a thin film silicon solar cell using the photoelectric conversion elements can be used.

  Further, the photoelectric conversion element 10 is provided with a bus bar electrode 11 serving as a surface electrode on the light receiving surface side and a finger electrode 12 that is a collecting electrode formed in a direction substantially orthogonal to the bus bar electrode 11. Further, the photoelectric conversion element 10 is provided with a back electrode 13 made of aluminum or silver on the back side opposite to the light receiving surface.

  And the photovoltaic cell 2 is electrically connected with the bus-bar electrode 11 of the surface, and the back surface electrode 13 of the adjacent photovoltaic cell 2 by the tab wire 3, Thereby, the string 4 connected in series is comprised. . The tab wire 3, the bus bar electrode 11, and the back electrode 13 are connected by a conductive adhesive film 17 provided in advance on one surface 3 a of the tab wire 3.

  The bus bar electrode 11 is formed by applying Ag paste and heating. The bus bar electrode 11 formed on the light receiving surface of the solar battery cell 2 is formed in a line shape with a width of 1 mm, for example, in order to reduce the area that blocks incident light and suppress shadow loss. The number of bus bar electrodes 11 is appropriately set in consideration of the size and resistance of the solar battery cell 2. The bus bar electrode 11 is bonded to the one surface 3a of the tab wire 3 provided with a conductive adhesive film 17 to be described later on the one surface 3a.

  The finger electrode 12 is formed over substantially the entire light receiving surface of the solar battery cell 2 so as to intersect the bus bar electrode 11 by the same method as the bus bar electrode 11. The finger electrodes 12 are formed with lines having a width of about 100 μm, for example, at a predetermined interval, for example, every 2 mm.

  As shown in FIG. 2, the back electrode 13 is formed of an electrode made of aluminum or silver on the back surface of the solar battery cell 2 by, for example, screen printing or sputtering. The back surface electrode 13 has a tab wire connecting portion 14 to which the one surface 3a of the tab wire 3 provided with a conductive adhesive film 17 to be described later is provided on the one surface 3a.

[Tab line]
As shown in FIG. 2, the tab wire 3 is provided on one surface of the long conductive base material 16 that electrically connects the adjacent solar cells 2 a and 2 b and the conductive base material 16. And a conductive adhesive film 17 serving as a layer.

  The conductive base material 16 uses, for example, a ribbon-like copper foil having a thickness of 50 to 300 μm as in the case of the tab wire used in the conventional solar cell module. If necessary, gold plating, silver plating, tin plating, solder Plating etc. are given.

  In addition, the conductive base material 16 has a conductive adhesive film 17 integrally bonded to one surface that is bonded to the bus bar electrode 11 and the back electrode 13. The tab wire 3 is connected to the bus bar electrode 11 formed on the surface of one solar battery cell 2a on the one surface 3a provided with the conductive adhesive film 17 and adjacent to the solar battery cell 2a. The direction of the one surface 3a is reversed between the other solar cells 2b and connected to the back electrode 13 of the other solar cells 2b.

  By using such a tab wire 3, as shown in FIG. 4, when the solar cell module 1 connects two solar cells 2a and 2b, a standard cut (2 pieces) of the raw fabric tab of the tab wire 3 is used. Then, following the molding of the tab wire 3 (two), the one surface 3a provided with the conductive adhesive film 17 of the tab wire 3 on the bus bar electrode 11 and the tab wire connecting portion 14 of the back electrode 13 is temporarily arranged (2 The solar cell 2 can be connected by the tab wire 3 only by the step of (main) and heat pressing (two).

  On the other hand, as shown in FIG. 4, in the conventional method, a regular cut of the conductive adhesive film (front electrode x 2 pieces, back electrode x 2 pieces) and a conductive adhesive film temporarily attached (front electrode x 2) Book, back electrode x 2), tab wire fixed cut (2) and tab wire molding (2), and then temporarily pasted on the bus bar electrode and on the back electrode tab line connection part The tab wire is temporarily pasted on the conductive adhesive film (two), and then the tab wire is thermocompression bonded at a predetermined temperature and pressure (two).

  Therefore, the solar cell module 1 can reduce the number of parts and the number of work steps as compared with the conventional method, and can improve the productivity. Moreover, since the solar cell module 1 reduces the man-hour of processing, arrangement | positioning, and heat pressurization of an electroconductive adhesive film or a tab wire, there is no problem of the position shift in the arrangement | positioning of a tab wire or an electroconductive adhesive film, or a temporary crimping process. Connection reliability with the bus bar electrode and the back electrode can be ensured.

  Specifically, as shown in FIGS. 2 and 3, the tab wire 3 includes a first connection piece 20 connected to the bus bar electrode 11 of one solar battery cell 2 a and the other connection line adjacent to the solar battery cell 2 a. The second connection piece 21 connected to the tab line connection portion 14 of the back surface electrode 13 of the solar battery cell 2b and the connection serving as a common end of the first and second connection pieces 20 and 21 extending in the same direction. And a folded portion 23 that folds back one of the first connection piece 20 and the second connection piece 21 (second connection piece 21 in the present embodiment) from the connection portion 22.

  The first connection piece 20 is formed by integrally providing a conductive adhesive film 17 on a connection surface between the conductive base material 16 and the bus bar electrode 11. The first connection piece 20 extends from the connection portion 22 and has a predetermined length corresponding to the length of the bus bar electrode 11 to be connected.

  The second connection piece 21 is formed by integrally providing a conductive adhesive film 17 on a connection surface of the back surface electrode 13 of the conductive base material 16 with the tab wire connection portion 14. Further, the second connection piece 21 is extended in the same direction as the first connection piece 20 from the connection portion 22, and the surface on which the conductive adhesive film 17 is provided is inverted and connected via the folded portion 23. The back electrode 13 has a predetermined length corresponding to the length of the tab line connecting portion 14.

  The first and second connection pieces 20 and 21 are continuous via a connection portion 22 serving as a common end portion. In the connection portion 22, the conductive adhesive film 17 is integrally provided on the conductive base material 16. In the drawing, for convenience of explanation, the dimensions of the bus bar electrode 11, the tab line connecting portion 14 of the back electrode 13, and the tab line 3 are excessively expressed as compared with the areas of the solar cells 2 a and 2 b. .

[Tab line processing]
The tab line 3 is formed as follows. First, a wide original film 25 is prepared. The raw film 25 is a long and wide conductive substrate 16 before being processed into the first and second connection pieces 20 and 21, the connection part 22, and the folded part 23, and has a thickness of 50 to 300 μm. Ribbon-shaped copper foil is used, and gold plating, silver plating, tin plating, solder plating, etc. are applied as necessary. The raw film 25 is bonded over the entire surface of the one surface 25a by heat-pressing the conductive adhesive film 17.

[Adhesive film]
As shown in FIG. 5A, the conductive adhesive film 17 is a thermosetting binder resin layer containing conductive particles 26 at a high density, and has a low temperature and low pressure such that the binder resin layer is not thermally cured in advance. Then, the film is bonded to the one surface 25 a of the original film 25 by heat and pressure, and is integrated with the original film 25. Moreover, as for the electroconductive adhesive film 17, it is preferable that the minimum melt viscosity of binder resin is 100-100000 Pa.s from a pressable viewpoint. If the minimum melt viscosity of the conductive adhesive film 17 is too low, the resin flows in the process of low pressure bonding to main curing, and connection failure or protrusion to the cell light receiving surface is likely to occur, which causes a decrease in the light receiving rate. Moreover, even if the minimum melt viscosity is too high, defects are likely to occur when the film is adhered, and the connection reliability may be adversely affected. The minimum melt viscosity can be measured while a sample is loaded in a predetermined amount of rotational viscometer and raised at a predetermined temperature increase rate.

  The conductive particles 26 used for the conductive adhesive film 17 are not particularly limited. For example, metal particles such as nickel, gold, silver, and copper, resin particles that are gold-plated, and resin particles that are gold-plated And the like. In addition, by containing flat flaky metal particles as the conductive particles 26, the number of the conductive particles 26 that overlap each other can be increased, and good conduction reliability can be ensured.

  Moreover, it is preferable that the electroconductive adhesive film 17 is 10-10000 kPa * s at the normal temperature vicinity, More preferably, it is 10-5000 kPa * s. When the conductive adhesive film 17 has a viscosity in the range of 10 to 10,000 kPa · s, when the conductive adhesive film 17 is a tape-shaped reel winding, so-called protrusion can be prevented, and a predetermined tack can be prevented. You can maintain power.

  The composition of the binder resin layer of the conductive adhesive film 17 is not particularly limited as long as it does not impair the above-described characteristics, but more preferably a film-forming resin, a liquid epoxy resin, a latent curing agent, a silane cup Contains a ring agent.

  The film-forming resin corresponds to a high molecular weight resin having an average molecular weight of 10,000 or more, and preferably has an average molecular weight of about 10,000 to 80,000 from the viewpoint of film formation. As the film-forming resin, various resins such as an epoxy resin, a modified epoxy resin, a urethane resin, and a phenoxy resin can be used. Among them, a phenoxy resin is preferably used from the viewpoint of the film formation state, connection reliability, and the like. .

  The liquid epoxy resin is not particularly limited as long as it has fluidity at room temperature, and all commercially available epoxy resins can be used. Specific examples of such epoxy resins include naphthalene type epoxy resins, biphenyl type epoxy resins, phenol novolac type epoxy resins, bisphenol type epoxy resins, stilbene type epoxy resins, triphenolmethane type epoxy resins, phenol aralkyl type epoxy resins. Resins, naphthol type epoxy resins, dicyclopentadiene type epoxy resins, triphenylmethane type epoxy resins, and the like can be used. These may be used alone or in combination of two or more. Moreover, you may use it combining suitably with other organic resins, such as an acrylic resin.

  As the latent curing agent, various curing agents such as a heat curing type and a UV curing type can be used. The latent curing agent does not normally react but is activated by some trigger and starts the reaction. The trigger includes heat, light, pressurization, etc., and can be selected and used depending on the application. When a liquid epoxy resin is used, a latent curing agent made of imidazoles, amines, sulfonium salts, onium salts, or the like can be used.

  As the silane coupling agent, epoxy, amino, mercapto sulfide, ureido, and the like can be used. Among these, in this Embodiment, an epoxy-type silane coupling agent is used preferably. Thereby, the adhesiveness in the interface of an organic material and an inorganic material can be improved.

  Moreover, it is preferable to contain an inorganic filler as another additive composition. By containing an inorganic filler, the fluidity of the resin layer during pressure bonding can be adjusted, and the particle capture rate can be improved. As the inorganic filler, silica, talc, titanium oxide, calcium carbonate, magnesium oxide and the like can be used, and the kind of the inorganic filler is not particularly limited.

  FIG. 5A is a diagram schematically illustrating an example of a form before the raw film 25 and the conductive adhesive film 17 are processed into the tab wire 3. The original film 25 and the conductive adhesive film 17 are laminated with a binder resin layer on a release substrate 27, and the original film 25 is pasted as a cover film on the binder resin layer and molded into a tape shape. ing. This tape-shaped film laminate is wound around a reel 28. There is no restriction | limiting in particular as the peeling base material 27, PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methlpentene-1), PTFE (Polytetrafluoroethylene) etc. can be used.

  In this way, by previously laminating and integrating the conductive adhesive film 17 and the raw film 25 on the release substrate 27, it is possible to easily perform a cutting process and a folding process described later. Further, when the tab wire 3 is actually used, the peeling substrate 27 is peeled off, and the binder resin layer of the conductive adhesive film 17 is stuck on the connection portion 14 of the bus bar electrode 11 or the back electrode 13 to thereby remove the tab wire. 3 and the electrodes 11 and 13 are connected. In addition, the peeling base material 27 may be peeled off before the cutting process of the film laminate, or may be peeled off immediately before actual use after the cutting process.

  In addition, the film laminated body of the raw fabric film 25 and the conductive adhesive film 17 is not limited to a reel shape, and may be a strip shape.

  When provided as a reel product in which the conductive adhesive film 17 is wound as shown in FIG. 5 (a), the conductive adhesive film 17 has a viscosity of 10 to 10,000 kPa · s. The deformation of the adhesive film 17 can be prevented and a predetermined dimension can be maintained. Similarly, when two or more conductive adhesive films 17 are stacked in a strip shape, deformation can be prevented and a predetermined dimension can be maintained.

  The conductive adhesive film 17 described above dissolves the conductive particles 26, the film-forming resin, the liquid epoxy resin, the latent curing agent, and the silane coupling agent in a solvent. As the solvent, toluene, ethyl acetate or the like, or a mixed solvent thereof can be used. The conductive adhesive film 17 is obtained by applying the resin-generating solution obtained by dissolution onto the release substrate 27 and volatilizing the solvent. The conductive adhesive film 17 is integrated with the original film 25 by applying heat and pressure to the one surface 25a of the original film 25 at a low temperature and low pressure so that the binder resin is not thermally cured but exhibits fluidity.

  Next, the film laminate in which the conductive adhesive film 17 and the raw film 25 are laminated on the peeling substrate 27 has a predetermined length necessary for connecting the two adjacent solar cells 2a and 2b. It cut | disconnects and the raw fabric tab 30 shown in FIG.5 (b) is obtained.

  Next, a cut line 31 is inserted from one end 30 a to the other end 30 b along the longitudinal direction of the original fabric tab 30, and the original fabric tab 30 is cut. The cut line 31 is formed along the longitudinal direction at a substantially intermediate portion in the width direction of the raw fabric tab 30. Thereby, one separated by the cut line 31 becomes the first connection piece 20, and the other becomes the second connection piece 21.

  Further, the cut line 31 is formed by leaving the other end 30b side of the raw fabric tab 30 by a predetermined length corresponding to the distance between the solar cells 2a and 2b. As a result, the other end portion becomes a connection portion 22 that is a common end portion of the first and second connection pieces 20 and 21.

  Next, as shown in FIG. 5C, the base end portion of the second connection piece 21 extending from the connection portion 22 is folded back, and the tab wire 3 is formed. The tab wire 3 has the first connecting piece 20 and the second connecting piece 21 with the conductive adhesive film 17 formed in the opposite direction through the folded portion 23. Therefore, the tab wire 3 electrically connects the first connection piece 20 onto the bus bar electrode 11 formed on the surface of one solar cell 2a, and the second connection piece 21 is adjacent to the other solar cell 2b. It is possible to conduct conductive connection to the tab line connecting portion 14 of the back electrode 13 formed on the back surface.

  Moreover, according to the tab wire 3, it can be used longer than the length of the original fabric tab 30, for example, when the original fabric film 25 is wound 300m around the reel 28, the tab wire 3 for 500m is cut out. be able to.

  The tab wire 3 is a tab wire of the first connection piece 20 connected on the bus bar electrode 11 provided on the light receiving surface of the solar battery cell 2 and the back electrode 13 provided on the back surface of the solar battery cell 2. The second connecting piece 21 connected on the connecting portion 14 has a width of the raw fabric tab 30 and is connected via a connecting portion 22 which is a common end of the first and second connecting pieces 20 and 21. Connected. The solar cell module 1 using the tab wire 3 has the following effects as compared with the solar cell module 101 using the conventional long tab wire 100.

  First, when defective solar cells are found after connecting a plurality of solar cells with tab wires, the conventional solar cell module 101 using the long tab wire 100 is shown in FIGS. ), The tab wire 100 is cut between the defective solar battery cell 102A and the solar battery cells 102B and 102C connected before and after the defective solar battery cell 102A. Next, as shown in FIGS. 7A and 7B, after removing the defective solar battery cell 102A, a new normal solar battery cell 102D is arranged as shown in FIGS. 8A and 8B. . In the replenished solar battery 102D, the tab line 103 is provided on the front and back surfaces in advance so as to be on the same line as the tab line 100.

  Next, as shown in FIGS. 9A and 9B, the end portions of the tab lines 100 of the normal solar cells 102B and 102C and the end portions of the tab lines 103 of the supplemented solar cells 102D are supported. Solder connection is made through the tab wire 105. At this time, in the solar cell module 101, since the distance between the solar cells 102B, 102C, and 102D is as narrow as about 1 to 2 mm, the connection reliability and the connection workability via the auxiliary tab wire 105 are inferior.

  That is, between the narrow cells of the solar battery cells 102B to 102D, there is hardly any blank space that can be soldered to the auxiliary tab wire 105 at the ends of the cut tab wires 100 of the solar battery cells 102B and 102C. . Therefore, the connection strength between the tab line 100 of the solar battery cells 102B and 102C via the auxiliary tab line 105 and each end of the tab line 103 of the supplemented solar battery cell 102D is not necessarily high.

  Further, as shown in FIG. 9A, the connection via the auxiliary tab line 105 is performed by slanting the tab line 100 and the tab line 103 between the narrow cells of the solar battery cells 102B to 102D, and the cell. Need to be done inside. Therefore, in the solar cell module 101, the connection work via the auxiliary tab wire 105 is not easy, and it is also difficult to confirm whether or not the connection has been made securely.

  On the other hand, in the solar cell module 1 using the tab wire 3, as shown in FIGS. 10 (a) and 10 (b), between the defective solar cell 102A and the solar cells 102B and 102C connected before and after the solar cell 102A. Then, the connecting portion 22 of the tab wire 3 is cut. At this time, the tab wire 3 is cut on an extension line of the cut line 31 that separates the first connection piece 20 and the second connection piece 21.

  Next, as shown in FIGS. 11 (a) and 11 (b), after removing defective solar cells 102A, new normal solar cells 102D are arranged as shown in FIGS. 12 (a) and 12 (b). . In this replenished solar cell 102D, the first connecting piece 20 of the tab wire 3 is previously provided on the front surface, and the portion from the second connecting piece 21 side of the connecting portion 22 of the tab wire 3 is provided on the back surface, respectively. Is provided. The first connection piece 21 of the solar battery cell 102D is provided so as to be adjacent to the connection part 22 of the solar battery cell 102B. Further, the connection portion 22 of the solar battery cell 102D is provided so as to be adjacent to the end portion of the first connection piece 20 of the solar battery cell 102C.

  Next, as shown in FIGS. 13A and 13B, the connection portion 22 of the solar battery cell 102 </ b> B and the first connection piece 20 of the replenished solar battery cell 102 </ b> D are soldered via the auxiliary tab wire 105. The end of the first connection piece 20 of the solar battery cell 102 </ b> C and the connection part 22 of the replenished solar battery 102 </ b> D are soldered via the auxiliary tab wire 105. At this time, in the solar cell module 1, the auxiliary tab wire 105 is overlapped over each connection portion 22 and the end portion of the first connection piece 20.

  Therefore, in the solar cell module 1, it is possible to secure a wide solder application region via the auxiliary tab wire 105, and the first connection piece 20 and the connection portion 22 of the supplemented solar cell 102D and the solar cell 102B. , 102C and the first connection piece 20 can be firmly connected.

  Moreover, in the solar cell module 1, the connection part 22 which is a common edge part of the 1st, 2nd connection pieces 20 and 21 is cut | disconnected, and the 1st connection piece 20 and the connection part 22 are made to adjoin the said cutting | disconnection location. The auxiliary tab wire 105 is soldered. Since this connection part 22 is located at the same height as the first connection piece 20 and is parallel to the gap between the narrow cells, the spacing between the solar cells 102B, 102C, 102D is about 1-2 mm. Even if it is narrow, it is possible to easily connect the auxiliary tab wire 105, and it is easy to confirm whether or not the auxiliary tab wire 105 is securely connected.

[Tab line variations]
The tab wire 3 may form a plurality of first connecting pieces 20 and / or second connecting pieces 21. For example, as shown in FIG. 14, the tab wire 3 may form two first connection pieces 20 and one second connection piece 21. The two first connecting pieces 20 and the first second connecting piece 21 may be formed to have the same width (for example, 1 mm), or may be formed to have different widths.

  The tab wire 3 can shorten the current collection distance from the finger electrode 12 by each connection piece by forming a plurality of connection pieces, and can suppress current collection loss. That is, as shown in FIG. 15, in the solar cell 102 using the conventional long tab wire 100, the distance D <b> 1 between each tab wire 100 and the end of the finger electrode 106, or between each tab wire 100. The distance D2 is separated. Therefore, in this solar battery cell 102, the distance between the finger electrodes 106 that each tab wire 100 collects becomes long, and a current collection loss occurs.

  On the other hand, in the solar cell 2 using the tab wire 3 in which a plurality of first connection pieces 20 adhered to the light receiving surface side of the solar battery cell 2 are formed, a plurality of first connection pieces as shown in FIG. The distance D3 between the end 20 of the finger electrode 12 and the distance D4 between the tab wires 3 can be shortened as compared with the solar battery cell 102. Therefore, in the photovoltaic cell 2, the distance of the finger electrode 12 which each 1st connection piece 20 collects becomes short, and it can suppress a current collection loss by that much.

  The tab wire 3 is considered to have a high resistance because the first connecting piece 20 is thinned compared to the tab wire 100, but an increase in the resistance of the first connecting piece 20 is suppressed by increasing the thickness. can do.

[Tab line variations]
Further, as shown in FIG. 17, the tab line 3 is shifted in the longitudinal direction from both sides in the middle of the original fabric tab in the longitudinal direction, and a cut line is formed toward the middle in the width direction, as shown in FIG. You may form by folding in a mountain fold along a dotted line, and folding in a valley fold along a dashed-dotted line.

  As shown in FIG. 17 (b), according to the tab line 3, the first connection piece 20 and the second connection piece 21 are arranged in parallel in the longitudinal direction. The first connection piece 20 connected to the second connection piece 21 connected to the tab line connection portion 14 of the back electrode 13 can be superimposed.

[Cell connection process]
Next, the manufacturing process of the solar cell module 1 will be described. First, the some photovoltaic cell 2 is arranged in the order connected in series.

  Next, as shown in FIG. 18, the tab wires 3 are provisionally disposed on the bus bar electrodes 11 and the tab wire connecting portions 14 of the back electrode 13 for each of the arranged solar cells 2. In the temporary arrangement step of the tab wire 3, the peeling base material 27 provided on the conductive adhesive film 17 is peeled off, and the bus bar electrode formed on the surface of the preceding one solar cell 2a as shown in FIG. 11, the first connection piece 20 of the tab wire 3 is temporarily disposed via the uncured conductive adhesive film 15, and uncured on the connection portion 14 of the back electrode 13 of the other solar battery cell 2 b that follows. The second connection piece 21 of the tab wire 3 is temporarily arranged through the conductive adhesive film 15. Similarly, uncured electrical conductivity is formed on the bus bar electrode 11 formed on the surface of the other solar battery cell 2b and the connection part 14 of the back electrode 13 of the solar battery cell 2c following the solar battery cell 2b. The first connection piece 20 and the second connection piece 21 of the tab wire 3 are temporarily arranged via the adhesive film 15. In this way, adjacent solar cells 2 are connected in series with the tab wire 3.

  Since the direction of the one surface 3a provided with the conductive adhesive film 17 of the first connection piece 20 and the second connection piece 21 is reversed via the connection portion 22 and the turn-back portion 23, the tab line 3 is reversed. Each of the first and second connection pieces 20 and 21 can be connected to the tab line connection portion 14 of the bus bar electrode 11 or the back electrode 13 through the conductive adhesive film 17.

  At this time, since the tab wire 3 is folded so that the conductive adhesive film 17 is folded inward by the folded portion 23 at the base end portion of the second connection piece 21, the conductive base material 16 is gently curved. In addition, an excessive load is not applied to the folded portion 23. Therefore, the tab wire 3 can maintain connection reliability without danger of disconnection or deterioration in the folded portion 23.

  In addition, the tab line 3 has the connection part 22 and the folding | returning part 23 located between the photovoltaic cells 2 by adjusting the length of the raw fabric tab 30 and the distance of the cut line 31.

  Next, as shown in FIG. 19, the solar cells 2 connected in series by the tab wires 3 are transported to a predetermined position facing the pair of upper and lower heating press heads 32, and the tab wires 3 are The conductive adhesive film 17 is cured by heating and pressing the one connection piece 20 and the second connection piece 21 from the conductive base material 16 side, and connected to the electrodes 11 and 13 of the solar battery cell 2. At this time, the plurality of solar cells 2 are configured so that the preceding solar cell 2a is moved up and down in synchronization with a pair of heating and pressing heads 32 provided above and below, so that the tab wire 3 is at a predetermined pressure. Pressed. The heating and pressing head 32 is heated to a predetermined temperature at which the conductive adhesive film 17 is cured. Therefore, in the conductive adhesive film 17, the binder resin is thermally cured, and the tab wire 3 and the connection portion 14 of the bus bar electrode 11 or the back electrode 13 are electrically and mechanically connected.

  When the tab wire 3 is finally pressure-bonded to the preceding solar cell 2 a by the heating and pressing head 32, the pair of heating and pressing heads 32 are separated from the tab wire 3, and the subsequent solar cell 2 b is connected to the pair of heating and pressing heads 32. It is transported directly below. In this way, the solar cells 2 are conveyed one by one directly below the heating and pressing head 32, and the tab wires 3 are sequentially bonded to the connection portions 14 of the bus bar electrodes 11 and the back electrode 13 and adjacent solar cells. Connected in series with the cell 2, a string 4 is formed.

  In addition, in this Embodiment, since the connection part 14 and the tab wire 3 are connected by the conductive adhesive film 15, either Al or Ag can be used as the back surface electrode 13 of the solar battery cell 2, By using a back surface Al current collecting electrode as the back surface electrode 13, it is not necessary to provide a conventional Ag electrode for solder connection, so that the manufacturing process of the solar battery cell is shortened and there is a merit in terms of production technology.

  Thereafter, a matrix 5 in which a plurality of strings 4 are arranged is formed according to a conventional process, and the matrix 5 is sandwiched between sheets of sealing adhesive such as EVA and laminated together with a front cover 7 and a back sheet 8. Then, the solar cell module 1 is completed by finally attaching the frame 9.

[Modification of solar cell module]
Moreover, as shown in FIG. 20, the solar cell module 1 to which the present invention is applied may sandwich the outer edge portion of the adjacent solar cell 2b by the folded portion 23 of the tab wire 3. Thereby, the solar cell module 1 can arrange | position the photovoltaic cells 2a and 2b close.

  At this time, in the solar battery cell 2 b, the outer edge portion sandwiched between the folded portions 23 is not pressed by the heating and pressing head 32. Therefore, the conductive substrate 16 and the bus bar electrode 11 or the back electrode 13 are not electrically connected by the conductive adhesive film 17 provided in the folded portion 23.

[Tab line variations]
In addition, as shown in FIG. 21, the solar cell module 1 to which the present invention is applied may include a tab wire 40 in which a conductive adhesive film 17 is integrally provided on one surface and an uneven shape is formed on the other surface. Good. In the following description, the same components as those of the tab line 3 are denoted by the same reference numerals, and the details thereof are omitted. This tab wire 40 is composed of a long conductive base material 41 and a conductive adhesive film 17 integrally provided on one surface of the conductive base material 41, as in the above-described tab wire 3, An uneven portion 43 is formed on the other surface of the conductive substrate 41. As shown in FIG. 22, the concavo-convex portion 43 is alternately provided with crest portions 43 a and trough portions 43 b that continue in the longitudinal direction of the tab wire 40 in the width direction.

  And the tab wire 40 is connected to the bus bar electrode 11 formed on the surface of one solar battery cell 2a on the one surface 40a provided with the conductive adhesive film 17 in the same manner as the tab wire 3, and The direction of the one surface 40a is reversed between another solar cell 2b adjacent to the solar cell 2a and connected to the back electrode 13 of the other solar cell 2b. Moreover, by this, the other surface 40b in which the uneven | corrugated | grooved part 43 was formed is orient | assigned to the same direction as the surface of the photovoltaic cell 2a, and the tab wire 40 is also directed to the same direction as the back surface of the adjacent photovoltaic cell 2b.

  Specifically, the tab wire 40 includes the first connecting piece 20 connected to the bus bar electrode 11 of one solar battery cell 2a and the other solar battery adjacent to the solar battery cell 2a in the same manner as the tab wire 3 described above. The second connection piece 21 connected to the tab line connection part 14 of the back surface electrode 13 of the cell 2b and the connection part 22 serving as a common end of the first and second connection pieces 20 and 21 extending in the same direction. And a folded portion 23 that turns back one of the first connection piece 20 and the second connection piece 21 (the second connection piece 21 in this embodiment) from the connection portion 22.

  The tab wire 40 is connected to the first connection piece 20 on the bus bar electrode 11 formed on the surface of the solar battery cell 2a, and the second connection piece 21 is connected to the back electrode of the adjacent solar battery cell 2b. By connecting on the 13 tab wire connection parts 14, the uneven | corrugated | grooved part 43 is orient | assigned to the same direction as the surface of the photovoltaic cell 2a and the back surface of the photovoltaic cell 2b. Therefore, as shown in FIG. 22, in the solar cell module 1, since the uneven portion 43 is directed in the same direction as the light receiving surface, the incident light is scattered by the uneven portion 43, and the scattered light is reflected by the surface cover 7, The light receiving efficiency can be improved by re-entering the light receiving surface.

  Moreover, when the solar cell module 1 uses the double-sided light receiving type solar cell 2, incident light is scattered by the uneven portion 43 even on the back side of the solar cell 2 b, and the light receiving efficiency can be further improved. .

  In the tab line 40, the shape of the concavo-convex portion 43 may be a saw blade shape, as shown in FIG. 23 (b), as shown in FIG. 23 (a). As described above, the cross-sectional shapes of the peak portions 43a and the valley portions 43b may be bowl-shaped, and both can improve the light receiving efficiency.

  Here, as shown in FIG. 24, a configuration is considered in which the folded portion 23 is not provided, and the other surface on which the uneven portion 43 is provided is connected by the conductive adhesive film 17 toward the back surface side of the solar battery cell 2b. . In such a configuration, the connection between the tab line and the back surface electrode 13 is achieved by the peak portion 43 a of the concavo-convex portion 43. Therefore, the back electrode 13 and the tab wire are not sufficiently connected, and there is a risk of a decrease in adhesive strength and an increase in conduction resistance. Moreover, like the tab wires 3 and 40, the conductive adhesive film 17 cannot be integrally provided on one surface of the conductive base material in advance, and in manufacturing the solar battery module, the conductive adhesive film to the solar battery cell. Each of the temporary bonding process, the temporary arrangement process of the tab line, and the final crimping process of the tab line is required, resulting in an increase in the number of parts and the number of work steps.

  On the other hand, according to the tab wire 40, since the one surface 40 a serving as a connection surface with the solar battery cell 2 is inverted between the solar battery cells 2 a and 2 b, both the front and back surfaces of the solar battery cell 2 have the conductive adhesive film 17. Connected by. Therefore, the tab wire 40 is sufficiently connected to the bus bar electrode 11 and the back surface electrode 13, and there is no risk of an increase in conduction resistance. In addition, the conductive adhesive film 17 is previously applied to one surface of the conductive substrate 41. By providing them integrally, the number of work steps and the number of parts can be reduced.

  As with the tab wire 3, the tab wire 40 is also provided with an original fabric tab in which a conductive adhesive film is integrally provided on one surface of a wide conductive base material, and the other end of the original fabric tab from one end in the longitudinal direction is prepared. After forming a cut line over the end side to form the first and second connection pieces 20 and 21 and the connection portion 22, it is turned back by turning back one of the first and second connection pieces 20 and 21. Molded by forming the portion 23.

  The raw fabric tab of the tab wire 40 uses, for example, a ribbon-like copper foil having a thickness of 50 to 300 μm, and is subjected to gold plating, silver plating, tin plating, solder plating or the like as necessary. The uneven portion 43 is formed by, for example, press-molding the plated ribbon-like copper foil. Since this uneven | corrugated | grooved part 43 formed along the longitudinal direction is formed in this original fabric tab when making a cut line over a longitudinal direction, it can be easily cut along the trough part 43b.

  In the method of reversing the surface on which the conductive adhesive film is provided by twisting the tab wire integrally provided with the conductive adhesive film on one surface of the conductive substrate between the solar cells 2, It is difficult to twist the tab wire provided with the portion, and the uneven portion cannot be provided on the other surface of the conductive substrate.

[Tab line variations]
Further, as shown in FIG. 25, the tab wires 3 and 40 have the width of the first connection piece 20 connected on the bus bar electrode 11 formed on the surface of the solar battery cell 2a as the back electrode of the solar battery cell 2b. You may make it larger than the width | variety of the 2nd connection piece 21 connected on the 13 tab wire connection parts 14. FIG.

  Here, FIG. 26 is a plan view (FIG. 26A) in which general crystalline silicon solar cells 50a and 50b are connected in series by a general tab wire 60, and a cross-sectional view along AA ′ (FIG. 26). (B)) and BB 'sectional drawing (FIG.26 (c)) is shown. As shown in FIG. 26, in a general crystalline silicon-based solar battery cell 50, an n-type semiconductor layer 51 and a p-type semiconductor layer 52 having different thicknesses are stacked one above the other. Further, an antireflection film 53 and an Ag electrode layer 54 such as a finger electrode or a bus bar electrode are formed on the front surface side, whereas an Ag electrode layer is formed on the back surface side in accordance with the connection portion of the Al reflection layer 55 and the tab wire. 56 is formed, and has a laminated structure made of different materials on the front surface side and the back surface side.

  Therefore, as shown in FIG. 27, the solar battery cell 50 is warped at all, regardless of the structure in which the tab wire is solder-connected in a high-temperature environment or the structure in which the conductive adhesive film is used to connect at a relatively low temperature. To do. The occurrence of warping indicates that a load is applied to the inside of the solar battery cell 50. During the tab wire 60 connection process or in the subsequent process, an assembly failure referred to as a cell crack or an inside of the cell that does not appear on the surface. Cracks occur, causing problems such as a decrease in power generation.

  In particular, silicon-based solar cells have become a subject to procure a large amount of silicon as a main raw material at low cost, and in recent years, a silicon wafer is cut out from a polycrystalline silicon ingot in a very thin (eg, 200 μm to 150 μm), Since it is used for mass production, the problem of warpage has become obvious, and the amount of warpage is regarded as one of the evaluation items for judging the quality of a product.

  Therefore, as shown in FIG. 25, the tab wires 3 and 40 indicate the bonding area between the first connection piece 20 connected to the front surface side of the solar battery cell 2 and the second connection piece 21 connected to the back surface side. Change intentionally. Thereby, the tab wires 3 and 40 adjust the stress generated on the front surface and the back surface of the solar battery cell 2 generated in the connection process to the solar battery cell 2 and the subsequent processes, and are generated inside the solar battery cell 2. To relieve stress. Accordingly, the tab lines 3 and 40 are warped of the solar battery cell 2 during the tab line connecting process and in the subsequent processes due to two effects of suppression of stress generated by low-temperature adhesion by the conductive adhesive film 17 and stress adjustment. Can be reduced, yield can be improved, and quality can be improved.

  Such tab wires 3 and 40 are formed by inserting a cut line to be inserted into a raw fabric tab in which a conductive adhesive film is integrally provided on one surface of a wide conductive base material so as to be biased to one side in the width direction. Is done. The extent to which the width of the first connection piece 20 is increased with respect to the width of the second connection piece 21 is appropriately adjusted according to the warp generated in the solar battery cell 2.

  Next, the results of measuring the amount of warpage generated in the solar battery cell 2 when the width is different between the first connection piece 20 and the second connection piece 21 and when the width is the same will be described. In this example, a tab wire having a thickness of 20 μm and a length of 150 mm obtained by soldering the copper foil surface to a polycrystalline silicon solar cell (thickness: 200 μm) having a side of 156 mm (6 inches), The change in the amount of warpage of the solar battery cell 2 before and after bonding was measured.

  The conditions for thermally pressing the tab wire to the solar battery cell 2 were an adhesion temperature of 180 ° C., a pressure of 2 MPa, and a pressurization time of 10 sec. The measured tab wire was 1 mm in width of the first connection piece 20 bonded to the light receiving surface and 2 mm in width of the second connection piece 21 bonded to the back surface (Example 1), and was bonded to the light receiving surface. The width of the first connection piece 20 is 1 mm, the width of the second connection piece 21 bonded to the back surface is 2 mm (Example 2), the width of the first connection piece 20 bonded to the light receiving surface is 1 mm, The width of the second connection piece 21 bonded to the back surface is 1 mm (Example 3), the width of the first connection piece 20 bonded to the light receiving surface is 2 mm, and the second connection piece 21 bonded to the back surface A width of 1 mm (Example 4) was used.

  The measurement results are shown in Table 1. The amount of warpage of the solar battery cell 2 is measured by placing the convex surface of the cell on a horizontal plate, measuring the height of the four corners from the horizontal plate with a ruler, +). The values in Table 1 are average values of the values at the four corners.

  As shown in Table 1, the first connecting piece 20 bonded to the light-receiving surface has a width of 2 mm, and the second connecting piece 21 bonded to the back surface has a width of 1 mm (Example 4). On the contrary, the first connecting piece 20 bonded to the light-receiving surface has a width of 1 mm, and the second connecting piece 21 bonded to the back surface has a width of 2 mm (Example 2). Became bigger. From this, it can be seen that forming the first connection piece 20 connected to the surface of the solar battery cell 2 effectively can suppress warpage.

  Further, when looking at Example 1 and Example 3 in which the widths of the first connection piece 20 and the second connection piece 21 are the same, the widths of the first and second connection pieces 20 and 21 are each 1 mm. In Example 3, the amount of warpage of the cell was smaller than that in Example 4 in which each was 2 mm. From this, it can be seen that even if the width of the tab line is simply increased, the warpage of the solar battery cell 2 is not necessarily suppressed.

DESCRIPTION OF SYMBOLS 1 Solar cell module, 2 photovoltaic cell, 3 tab wire, 4 strings, 5 matrix, 6 sheet, 7 surface cover, 8 back sheet, 9 metal frame, 10 photoelectric conversion element, 11 bus bar electrode, 12 finger electrode, 13 back surface Electrode, 14 Tab wire connection part, 16 Conductive base material, 17 Conductive adhesive film, 20 First connection piece, 21 Second connection piece, 22 Connection part, 23 Folded part, 25 Original fabric film, 26 Conductivity Particles, 27 Peeling substrate, 28 Reel, 30 Raw fabric tab, 31 Cut line, 32 Heat pressing head, 40 Tab wire, 41 Conductive substrate, 43 Concavity and convexity, 50 Solar cell, 51 N-type semiconductor layer, 52 p-type semiconductor layer, 53 antireflection film, 54 Ag electrode layer, 55 Al reflection layer, 56 Ag electrode layer

Claims (13)

Having a plurality of solar cells and tab wires with electrodes formed on the front and back surfaces,
The tab wire is provided with an adhesive layer on one surface of the conductive substrate, and is connected to the front and back electrodes of the solar battery cell via the adhesive layer,
The tab line is a solar battery module in which one surface provided with the adhesive layer is inverted between adjacent solar cells and is connected to the surface electrode of the solar battery cell and the back electrode of the adjacent solar battery cell. .   The tab wire extends in the same direction as the first connection piece connected to the electrode of one of the solar cells and the second connection piece connected to the electrode of the other solar cell. The sun according to claim 1, further comprising: a connecting portion that is a common end of the first and second connecting pieces; and a folded portion that turns back one of the first connecting piece or the second connecting piece from the connecting portion. Battery module.   The tab line is separated into the first connection piece and the second connection piece extending in the same direction from the connection portion by inserting a cut line from one end to the other end side along the longitudinal direction, The solar cell module according to claim 2, wherein the solar cell module is formed by folding back one of the connection piece or the second connection piece from the connection portion.   The solar cell module according to claim 2, wherein the tab wire is formed with a width different from that of the first connection piece and the second connection piece.   The tab wire is formed such that a connection piece connected to a front electrode formed on a light receiving surface of the solar battery cell is wider than a connection piece connected to a back electrode of an adjacent solar battery cell. 4. The solar cell module according to 4.   4. The solar cell module according to claim 3, wherein the tab wire forms the first connection piece and the second connection piece having different widths by inserting a cut line at a position biased to one side in the width direction. 5. .   The solar cell module according to claim 3, wherein the tab wire includes a plurality of either the first connection piece or the second connection piece.   The solar cell module according to claim 7, wherein the tab line is formed by inserting a plurality of cut lines from one end to the other end side along the longitudinal direction.   The solar cell module according to any one of claims 2 to 8, wherein the solar cell is sandwiched by the folded portion.   The tab line is formed on the other surface opposite to the one surface, with crests and troughs extending along the longitudinal direction or the width direction extending in the width direction or the longitudinal direction. 2. The solar cell module according to item 1. A step of juxtaposing a plurality of solar cells having electrodes formed on the front and back surfaces;
An adhesive layer is provided on one surface, and the one surface of one end side of the tab wire that is inverted between adjacent solar cells is temporarily disposed on the surface electrode of one solar cell, and the other end of the tab wire Temporarily placing the one surface on the side on the back electrode of the other solar cell;
By heating and pressing the other surface of the tab wire opposite to the one surface, the front electrode and the back electrode are connected to the tab wire, and the adjacent solar cells are connected via the tab wire. The manufacturing method of the solar cell module which has a process.   The tab wire extends in the same direction as the first connection piece connected to the electrode of one of the solar cells and the second connection piece connected to the electrode of the other solar cell. 12. The sun according to claim 11, further comprising: a connection portion that is a common end portion of the first and second connection pieces; and a folded portion that turns back one of the first connection piece or the second connection piece from the connection portion. Manufacturing method of battery module.   The tab line is separated into the first connection piece and the second connection piece extending in the same direction from the connection portion by inserting a cut line from one end to the other end side along the longitudinal direction, The manufacturing method of the solar cell module of Claim 12 shape | molded by folding back one side of a connection piece or the said 2nd connection piece from the said connection part.

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