JP2014107356A - Method of manufacturing solar cell module, and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a solar cell strings efficiently, by reducing complexity of a repair process.SOLUTION: A first tab line 3 longer than one side of a solar cell 2 is connected, via an adhesive 17, to the first surface of a silicon-based solar cell 2, while protruding one end from the first side edge 2a of the solar cell 2, and a second tab line 3 longer than one side of the solar cell 2 is connected, via an adhesive 17, to the second surface of the solar cell 2, while protruding one end from the second side edge 2b on the opposite side of the first side edge 2a of the solar cell 2, thus forming a solar cell 20 with tab lines. A plurality of solar cells 20 with tab lines are arranged, and the ends 21 of the first and second tab lines 3 protruding from one side edge of the solar cell 2 are connected each other, between the solar cells 2.

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 solar cell module, a plurality of adjacent solar cells are connected by tab wires made of a ribbon-like copper foil or the like that is solder-coated 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.

  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 copolymer resin (EVA).

JP 2004-356349 A JP 2008-135654 A

  By the way, 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 an extremely thin (for example, 300 μm to 150 μm), It is being used for mass production. Therefore, when forming the strings by temporarily sticking the conductive adhesive film to the solar cells with the heating press head, and then placing the tab wire on the conductive adhesive film and performing the thermal pressing, the heating press head The pressurization may cause problems such as cracking and warping in the solar battery cell.

  As shown in FIG. 10, the operation of removing such defective solar cells is performed by cutting the tab wires 52 between the solar cells 51 and forming the defective solar cells 51a after the solar cell strings 50 are formed. Is removed, and after the non-defective solar battery cells 51b to which the tab wires 52 are connected are arranged, the tab wires 52 are connected to each other by soldering.

  However, since the conventional method relies on manual repair, it takes time and the work itself becomes complicated. Further, depending on the skill of the operator, a poor solder connection between the tab wires may occur. Furthermore, if the solar cell is replaced at only one place, the arrangement of the solar cell strings may be affected.

  Then, an object of this invention is to provide the manufacturing method of a solar cell module which can reduce the complexity of a repair process, and can form a solar cell module efficiently, and a solar cell module.

  In order to solve the above-described problems, a method for manufacturing a solar cell module according to the present invention includes a first surface of a silicon-based solar cell that is longer than one side of the solar cell via an adhesive. One tab line is connected to one end of the solar battery cell protruding from the first side edge of the solar battery cell, and is connected to the second surface of the solar battery cell from one side of the solar battery cell via an adhesive. A long second tab wire is formed so that one end of the second tab wire protrudes from the second side edge opposite to the first side edge of the solar battery cell to form a solar cell with a tab line, A plurality of solar cells with tab lines are arranged, and the ends of the first and second tab lines protruding from one side edge of the solar cells are connected between the plurality of solar cells. Is.

  The solar cell module according to the present invention includes a plurality of silicon-based solar cells, a first tab line connected to the first surface of the solar cell, and a second surface of the solar cell. A second tab wire connected to the solar cell, and the first tab wire connected to the solar cell, and the second tab wire connected to the solar cell disposed adjacent to the solar cell. When the two tab wires are connected, the plurality of solar cells are electrically connected, and one end of each of the first and second tab wires protrudes from the side edge of the solar cells, The protruding parts are connected to each other.

  According to the present invention, the solar cell with the tab line connected to the tab line is formed before the string is formed so that the solar cell is connected through the tab line. Defective products that have occurred can be removed in advance. Therefore, according to the present invention, the frequency of replacing defective solar cells after connection between the solar cells can be greatly reduced, and productivity can be improved.

It is a disassembled perspective view which shows the solar cell module to which this invention was applied. It is sectional drawing which shows a solar cell string. It is a top view which shows the back surface of a photovoltaic cell. It is sectional drawing of a conductive adhesive film. It is sectional drawing which shows the electroconductive adhesive film wound around a reel. It is sectional drawing which shows a photovoltaic cell with a tab wire. It is a side view which shows the connection part of the tab wire connected through a metal piece. It is a top view which shows the state connected through the wide metal piece. It is sectional drawing which shows the state connected using the auxiliary tab wire. It is a side view which shows the replacement | exchange process of the conventional bad photovoltaic cell.

  Hereinafter, a method for manufacturing a solar cell module to which the present invention is applied and a solar cell module will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. Further, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Specific dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[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 copolymer 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. As the photoelectric conversion element 10, a so-called silicon solar cell such as a single crystal silicon photoelectric conversion element or a polycrystalline silicon photoelectric conversion element can be used.

  Further, the photoelectric conversion element 10 is provided with finger electrodes 12 serving as surface electrodes for collecting electricity generated inside on the light receiving surface side. The finger electrode 12 is formed, for example, by applying an Ag paste on the surface to be a light receiving surface of the solar battery cell 2 by screen printing or the like and then baking it. In addition, the finger electrode 12 is formed with a plurality of lines having a width of about 50 to 200 μm, for example, approximately in parallel at a predetermined interval, for example, every 2 mm, over the entire light receiving surface.

  The solar battery cell 2 has a so-called bus bar-less structure in which a bus bar electrode for collecting electricity of the finger electrode 12 is not provided by being substantially orthogonal to each finger electrode 12. Therefore, in the solar battery cell 2, the tab wire 3 provided with the conductive adhesive film 17 described later is directly connected to the finger electrode 12. In the present invention, a solar battery cell in which a bus bar electrode is formed can also be used.

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

  And the photovoltaic cell 2 is electrically connected to each finger electrode 12 formed on the surface by the tab wire 3 and the back electrode 13 of the adjacent photovoltaic cell 2, and thereby the strings connected in series. 4 is configured. The tab wire 3, the finger electrode 12, and the back electrode 13 are connected by a conductive adhesive film 17 laminated on the one surface 3 a of the tab wire 3.

[Tab line]
As shown in FIG. 2, the tab line 3 is a long conductive substrate that electrically connects each of the adjacent solar cells 2X, 2Y, and 2Z. The tab wire 3 is substantially the same as the conductive adhesive film 17 by, for example, slitting a copper foil or aluminum foil rolled to a thickness of 50 to 300 μm, or rolling a thin metal wire such as copper or aluminum into a flat plate shape. A flat copper wire having a width of 1 to 3 mm is obtained. Then, the tab wire 3 is subjected to gold plating, silver plating, tin plating, solder plating, or the like, if necessary, on the flat copper wire, and then the conductive adhesive film 17 is adhered to the one surface 3a. Layer 18 is formed.

  The tab wire 3 has one surface 3a on which the adhesive layer 18 is formed as an adhesive surface to the surface on which the finger electrode 12 of the solar battery cell 2 is provided or the back surface on which the back electrode 13 is formed. The tab wire 3 has a length longer than one side of the solar battery cell 2. The tab wire 3 is connected to the surface on which the finger electrode 12 of the solar battery cell 2 is formed via the adhesive layer 18 so that one end protrudes from the first side edge 2 a of the solar battery cell 2. Is done. Further, the tab wire 3 is connected to the back surface of the solar battery cell 2 on which the back electrode 13 is formed via the adhesive layer 18, so that one end is opposite to the first side edge 2 a of the solar battery cell 2. The second side edge 2b is connected to the second side edge 2b.

[Adhesive layer]
Next, the conductive adhesive film 17 constituting the adhesive layer 18 that connects the tab wire 3 to the front and back surfaces of the solar battery cell 2 will be described. As shown in FIG. 4, the conductive adhesive film 17 is a thermosetting binder resin layer containing conductive particles 23 at a high density. The conductive adhesive film 17 preferably has a minimum melt viscosity of 100 to 100,000 Pa · s from the viewpoint of indentability. 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 23 used for the conductive adhesive film 17 are not particularly limited, and examples thereof include metal particles such as nickel, gold, silver, and copper, those obtained by applying gold plating to resin particles, and gold plating on resin particles. And the like. In addition, the average particle diameter of the electroconductive particle 23 can be used in the range of 1-50 micrometers, and the range of 10-30 micrometers can be used preferably.

  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 10000 kPa · s, when the conductive adhesive film 17 is provided on one surface 3 a of the tab wire 3 and wound around the reel 21, so-called blocking due to protrusion is prevented. And a predetermined tack force can be maintained.

  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. Among these, in the present application, a thermosetting latent curing agent is suitably used, and is fully cured by being heated and pressed by the finger electrode 12 and the back electrode 13. 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. 5 is a diagram schematically illustrating an example of a product form of the conductive adhesive film 17. The conductive adhesive film 17 is formed in a tape shape by laminating a binder resin layer on the release substrate 24. This tape-like conductive adhesive film is wound and laminated on the reel 25 so that the peeling substrate 24 is on the outer peripheral side. There is no restriction | limiting in particular as the peeling base material 24, PET (Poly E
thylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methlpentene-1), PTFE (Polytetrafluoroethylene), and the like can be used.

  Further, the conductive adhesive film 17 has a binder resin layer stuck on one surface 3 a of the tab wire 3. When the conductive adhesive film 17 is pasted on the one surface 3a of the tab wire 3 in advance, the peeling base material 24 is peeled off during actual use, and the binder resin layer of the conductive adhesive film 17 is removed from the finger electrode 12 or the like. The tab wire 3 and the electrodes 12 and 13 are connected by sticking on the tab wire connecting portion 14 of the back electrode 13.

  In the above description, the conductive adhesive film having a film shape has been described. In the present application, a film-like conductive adhesive film 17 containing conductive particles or a paste-like conductive adhesive paste is defined as a “conductive adhesive”. Even in the case of using a conductive adhesive paste, the tab wire 3 is preliminarily coated with the conductive adhesive paste on one surface 3a which is an adhesive surface to the surface of the solar battery cell 2, and the conductive adhesive is applied to the solar battery. Affixed on the electrodes 12 and 13 of the cell 2.

  The conductive adhesive film 17 is not limited to the reel shape, and may be a strip shape corresponding to the connection region on the surface of the solar battery cell 2 or the shape of the tab wire connection part 14 of the back electrode 13.

  As shown in FIG. 5, when the conductive adhesive film 17 is provided as a reel product wound, the conductive adhesive film 17 has a viscosity of 10 to 10,000 kPa · s, whereby the conductive adhesive film 17 has a viscosity of 10 to 10,000 kPa · s. Deformation 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 23, 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 solution for resin production obtained by dissolving is applied on the peeling substrate 24 and the solvent is volatilized to obtain the conductive adhesive film 17.

  The conductive adhesive film 17 is integrated with the tab wire 3 by being pressed onto one surface 3 a of the tab wire 3 by a roller, and the binder resin layer forms the adhesive layer 18 of the tab wire 3. After that, the tab wire 3 in which the two for the front electrode and the two for the back electrode are cut to a predetermined length is shown in FIG. Temporarily pasted at predetermined positions on the front and back surfaces. At this time, the adhesive layer 18 is temporarily pasted so as to cross the plurality of finger electrodes 12 formed substantially parallel to the surface of the solar battery cell 2, and on the tab line connecting portion 14 of the back electrode 13. Temporarily pasted.

  Here, the tab wire 3 is cut to a length longer than one side of the solar battery cell 2. The tab wire 3 temporarily attached to the surface of the solar battery cell 2 has one end protruding from the first side edge 2a of the solar battery cell 2 and the other end protruding from the second side edge 2b of the solar battery cell. It is temporarily pasted so as not to. Similarly, the tab wire 3 temporarily attached to the back surface of the solar battery cell 2 has one end protruding from the second side edge 2b of the solar battery cell 2, and the other end from the first side edge 2a of the solar battery cell. Temporarily pasted so as not to protrude.

  The temporary sticking of the tab wire 3 is performed by applying heat and pressure for a short time at low temperature and low pressure with a heating bonder. One end of the tab wire 3 protruding from the first side edge 2a and the second side edge 2b of the solar battery cell 2 is the second side edge 2b and the first side edge 2a of the adjacent solar battery cell 2. The connecting portion 21 is connected to one end of the protruding tab wire 3.

  Thereafter, the tab wire 3 and the front and back electrodes of the solar battery cell 2 are thermally pressed at a predetermined temperature and pressure at which the binder resin of the conductive adhesive film 17 is thermally cured from above the tab wire 3 by a heating bonder. Thirteen tab wire connecting portions 14 are connected via conductive particles 23. In particular, between the finger electrode 12 and the tab wire 3, the binder resin flows out from between the finger electrode 12 and the tab wire 3 and the conductive particles 23 are sandwiched between the tab wire 3 and the finger electrode 12. The binder resin is cured in the state. As a result, the conductive adhesive film 17 adheres the tab wires 3 to the solar cells 2 while crossing the tab wires 3 with the plurality of finger electrodes 12, and conducts the finger electrodes 12 and the tab wires 3 via the conductive particles 23. Can be connected.

  Thereby, the photovoltaic cell 20 with a tab wire is formed. In the solar cell with tab line 20, the adhesive layer 18 in the connection portion 18 of the tab wire 3 protruding from the first side edge 2 a and the second side edge 2 b of the solar battery cell 2 is heat-pressed by a heating bonder. Since it is not done, it is in an uncured state.

  Before forming the strings 4, the tab-line solar cell 20 is inspected for damage such as cracking in a heat pressurizing process using a heating bonder. In this inspection process, the solar cell with tab line 20 in which a defect is found is removed from the line and is not passed to the string formation process. The tab line solar cells 20 in which no defect is found in the inspection process are connected to the protruding ends of the tab lines 3 to form the strings 4.

  Thus, according to the manufacturing process of the solar cell module 1, whether or not damage has occurred in the main crimping process of the tab wire 3 before the solar cells 2 form the strings connected via the tab wire 3. The string is formed after inspecting and removing the defective product in advance. Therefore, according to this manufacturing process, the frequency of replacing defective products after the formation of strings can be greatly reduced, and productivity can be improved.

  The connection between the tab lines 3 of the non-defective tab-line solar cells 20 connects the connection portions 21 protruding from the solar cells 2 of the tab line 3 in the region between the adjacent tab-line solar cells 20. By doing. As shown in FIG. 2, the connection part 21 of the tab wire 3 connected to the surface of the adjacent solar battery cell 2X and the connection part 21 of the tab wire 3 connected to the back surface of the adjacent solar battery cell 2Y are bonded. The agent layer 18 is opposed. As described above, since the adhesive layer 18 in the connection portion 21 is uncured, the tab wires 3 are connected to each other by attaching the adhesive layers 18 to each other and applying heat.

[Batch lamination]
The tab wires 3 of the solar cells 20 with tab wires are preferably connected to each other in the laminating batch crimping step. That is, a plurality of non-defective solar cells with tab wires 20 are arranged, and the connecting portions 21 of the tab wires 3 are attached to each other between adjacent solar cells 2 to form the strings 4. On the base of the decompression laminator, a back sheet 8, a sheet 6 of translucent sealing adhesive such as EVA, the strings 4, a sheet 6 of sealing adhesive, and a surface cover 7 are sequentially laminated, and a decompression laminating process is performed. And heating with a heater. In the tab-line solar cell 20, the adhesive layer 18 is cured in a state in which the tab wires 3 sandwich the conductive particles 23 when the connection portions 21 of the tab wires 3 are thermally pressed. Solar cells 2 are electrically connected. Thereby, sealing of the solar cell string 4 and connection of the connection parts 21 of the tab wire 3 of the solar cell 20 with a tab wire can be performed collectively. Finally, a metal frame 9 such as aluminum is attached to the periphery, and the solar cell module 1 is completed.

  Such a laminate batch press-bonding process has less impact on the solar cells and therefore less damage than the heat-pressing process using a heating bonder.

  In addition, the solar cell module 1 may perform the connection of the connection parts 21 of the tab wires 3 and the sealing of the solar cell strings 4 in separate steps.

[Adhesion distance]
Moreover, it is preferable that the connection distance of the connection parts 21 of the tab wire 3 shall be 1 mm or more. If the bonding distance is less than 1 mm, the bonding strength is insufficient, and the connection reliability between the solar cells 2 may be impaired.

[Metal piece]
In addition, as shown in FIG. 7, the connection between the tab wires 3 of the solar cells 20 with the tab wires may include a metal piece 30 interposed between the connection portions 21. By interposing the metal piece 30, the connecting portion 21 of the tab wire 3 is connected to the metal piece 30 instead of connecting the adhesive layers 18 to each other, and the connection reliability is improved.

  As the metal piece 30, metal foil excellent in electroconductivity, such as Cu foil, can be used suitably, for example.

  Further, as shown in FIG. 8, adjacent tab lines 3 may be shared by using a long metal piece 30 having a long width W orthogonal to the longitudinal direction of the tab lines 3. Thereby, compared with the case where the metal piece 30 is arrange | positioned for every connection location of the connection parts 21 of the tab wire 3, the metal piece 30 can be arrange | positioned efficiently.

  The metal piece 30 preferably has a thickness of 40 to 210 μm. If the metal piece 30 is thinner than 40 μm, the conduction resistance increases and the power generation efficiency decreases. Moreover, if the metal piece 30 is thicker than 210 μm, the connection portion 21 of the tab wire 3 is connected to both surfaces, so that the thickness between the solar cells 2 becomes thicker than that of the solar cells 2.

The connecting portions 21 of the tab wire 3 are connected to each other by forming the adhesive layer 18 by sticking the conductive adhesive film 17 on both surfaces of the metal piece 30 and connecting the connecting portions 21 via the adhesive layer 18. They may be bonded together. In this case, the adhesive layer 18 does not need to be formed on the connection portion 21 of the tab wire 3.
[Auxiliary tab line]
Further, as shown in FIG. 9, when the connecting portion 21 of the tab wire 3 has a short protrusion length from the solar battery cell 2 and the bonding length between the connecting portions 21 is insufficient, the auxiliary tab wire 31 is added. You may extend it. The auxiliary tab wire 3 is a strip-like tab wire in which the adhesive layer 18 is formed by attaching a conductive adhesive film to one surface of the metal foil, as in the above-described tab wire 3.

  In the addition of the auxiliary tab wire 31, the adhesive layer 18 of the connecting portion 21 protruding from the solar battery cell 2 and the metal foil of the auxiliary tab wire 31 are bonded. The auxiliary tab wire 31 includes the adhesive layer 18 of the connection portion 21 where the adhesive layer 18 protrudes from the other solar battery cell 2, or the adhesive layer 18 of the auxiliary tab wire 31 connected to the connection portion 21. These are connected through metal pieces 30 as appropriate. Thereby, the length of the connection part 21 can be adjusted according to the distance between the photovoltaic cells 20 with a tab wire.

  Next, examples of the present invention will be described. In this embodiment, the solar cell module 1 to which the solar cells 20 with tab wires are connected is formed by the laminate batch crimping method, and the conduction resistance (Ω), the conversion efficiency η (%), and the defective solar cell 2 are generated. The ease of repair in this case was evaluated in comparison with a solar cell module manufactured by a conventional manufacturing method. The tab wire 3 previously connected to the solar battery cell 2 was a copper foil having a width of 2 mm.

  The conversion efficiency η of the solar battery cell and the solar battery module in each example and comparative example is measured using standard measurement conditions (illuminance 1000 W / m 2, using a solar simulator (manufactured by Wacom Denso Co., Ltd., solar simulator WXS-200S)). The power generation efficiency (%) was measured at a temperature of 25 ° C. and a spectrum AM of 1.5 G). The conduction resistance was measured by a so-called four-terminal method, and was measured in accordance with JIS C8913 (crystal solar cell output measurement method).

  As a result of the measurement, when the conduction resistance of the solar cell module according to the example and the comparative example is less than 10930.99 mΩ, it is ◯ (good), 1090.400 mΩ or more and less than 1090.749 mΩ is △ (normal), and 1090.7750 mΩ or more It evaluated as x (defect). In addition, the conversion efficiency η of the solar cell modules according to the examples and comparative examples is 16.150% or more ○ (good), 16.050 to 16.149% is Δ (normal), and less than 16.049% is × ( Bad).

  In addition, the ease of repair when defective solar cells 2 are generated is ◯ when it is easy, x when it is complicated, considering overall the frequency of cell replacement and the ease of work. As evaluated.

  In Example 1, the auxiliary tab lines 31 were bonded to the connecting portions 21 of the tab lines 3 of the solar cells 20 with tab lines, and the auxiliary tab lines 31 were connected to each other (see FIG. 9). Moreover, in Example 1, the adhesive layers 18 of the auxiliary tab wires 31 were connected without the metal piece 30 interposed. The adhesion distance d between the auxiliary tab wires 31 was 2 mm.

  In Example 2, the conditions are the same as in Example 1 except that the adhesion distance d between the auxiliary tab lines 31 is set to 3 mm.

  In Example 3, the connection parts 21 of the tab wires 3 of the solar cells 20 with tab wires were connected to each other. In Example 3, a metal piece 30 having a thickness of 40 μm and 3 mm × 3 mm was interposed between the connecting portions 21 of the tab wires 3 (see FIG. 7). The bonding distance d of the connecting portion 21 of each tab wire 3 bonded through the metal piece 30 was 1 mm.

  In the fourth embodiment, the conditions are the same as those in the third embodiment except that the bonding distance d of the connecting portions 21 of the tab wires 3 bonded through the metal pieces 30 is set to 2 mm.

  In the fifth embodiment, the conditions are the same as those in the third embodiment except that the bonding distance d of the connecting portions 21 of the tab wires 3 bonded through the metal piece 30 is 3 mm.

  In Example 6, the conditions are the same as in Example 3 except that the thickness T of the metal piece 30 is 120 μm.

  In Example 7, the conditions are the same as in Example 6 except that the bonding distance d of the connecting portion 21 of each tab wire 3 bonded through the metal piece 30 is set to 2 mm.

  In the eighth embodiment, the conditions are the same as those in the sixth embodiment except that the bonding distance d of the connecting portions 21 of the tab wires 3 bonded through the metal pieces 30 is set to 3 mm.

  In Example 9, the connecting portions 21 of the tab wires 3 of the solar cells 20 with tab wires were connected. Moreover, in Example 9, the metal piece 30 of thickness T210micrometer and 3 mm x 3 mm was interposed between the connection parts 21 of each tab wire 3 (refer FIG. 7). The bonding distance d of the connecting portion 21 of each tab wire 3 bonded through the metal piece 30 was 3 mm.

  In Example 10, the conditions are the same as in Example 9 except that the width W of the metal piece 30 is 30 mm and is shared by the connecting portions 21 of the two tab wires 3 arranged in parallel (see FIG. 8).

  In Example 11, the width W of the metal piece 30 is 50 mm, and the conditions are the same as those in Example 9 except that the metal tabs 30 are shared by the connecting portions 21 of the plurality of tab wires 3 arranged in parallel.

  In Example 12, the auxiliary tab lines 31 were bonded to the connection portions 21 of the tab lines 3 of the solar cells 20 with tab lines, and the auxiliary tab lines 31 were connected to each other. In Example 12, a metal piece 30 having a thickness of T210 μm and 3 mm × 3 mm was interposed between the auxiliary tab wires 31. The bonding distance d of each auxiliary tab line 31 bonded through the metal piece 30 was 3 mm.

  In Example 13, the condition is the same as in Example 12 except that the width W of the metal piece 30 is 30 mm and is shared by the two auxiliary tab lines 31 arranged in parallel.

  In Example 14, the conditions are the same as in Example 12 except that the width W of the metal piece 30 is 50 mm and shared by a plurality of auxiliary tab lines 31 arranged in parallel.

  In Comparative Example 1, a solar cell module was manufactured by a conventional manufacturing method. That is, the tab wire 3 is arranged between the front surface of the solar battery cell 2 and the back surface of the solar battery cell 2 adjacent to the surface of the solar battery cell 2 through an adhesive, and is thermally pressed by a heating bonder to form the tab wire 3 and form the strings. At the same time. Thereafter, assuming that one of the solar cells constituting the string is cracked, the tab line is cut before and after the defective solar cell, and a non-defective solar cell in which the tab line is connected separately After placement, the tab wires were connected by soldering manually (see FIG. 10).

  As shown in Table 1, in the solar cell modules according to Examples 1 to 14, the conduction resistance is less than 1090.749 mΩ, and the conversion efficiency η is 16.050% or more, which is a practically sufficient value. It was done. Moreover, in Examples 1-14, since the solar cell 20 with a tab wire is formed in advance before assembling the strings, a cell crack or the like occurs in the solar cell 2 when the tab wire 3 is connected. However, by eliminating the defective solar battery cell 2, there is no fear that the defective solar battery cell 2 is mixed in the strings, and the repairability is easy.

  On the other hand, in Comparative Example 1, the conduction resistance is as high as 1090.750 mΩ or more, and the conversion efficiency η is as low as less than 16.049%. This is because a conventional manufacturing method in which the formation of strings and the connection of the tab wire to the solar battery cell 2 is used at the same time, and the solar battery cell 2 is defective due to thermal pressurization of the tab wire. In addition, there is a possibility that the replacement with the non-defective solar battery cell 2 is performed by manual soldering between the tab wires, which is complicated and the quality of the operation depends on the skill of the operator. Also, the ease of repair is naturally complicated.

  When Examples 1 and 2 are compared with other Examples, it is better to connect the connecting portions 21 of the tab wires 3 or the auxiliary tab wires 31 with the metal piece 30 interposed between them and the conduction resistance (Ω) It can be seen that the conversion efficiency η (%) can be improved. This is presumably because when the adhesive layers 18 are brought together, the amount of the binder resin increases and the pushability of the conductive particles is poor. On the other hand, when the metal piece 30 is interposed, since the metal piece 30 and the tab wire 3 are connected via the adhesive layer 18, the conductive particles can be sufficiently pushed.

  Comparing Examples 3 to 5 and Examples 6 to 8, the adhesion distance d between the tab wire 3 and the auxiliary tab wire 31 becomes longer as 1 mm to 3 mm, and the conduction resistance becomes lower and the conversion efficiency η is improved. I understand that Further, it can be seen that as the thickness of the metal piece 30 increases, the conduction resistance decreases and the conversion efficiency η improves.

  Further, as in the tenth and eleventh embodiments and the thirteenth and fourteenth and fourteenth embodiments, the metal piece 30 is wider than the width (2 mm) of the tab wire 3 and the auxiliary tab wire 31, so Thus, the number of man-hours can be reduced as compared with the case where the metal piece 30 is arranged for each connection portion of the tab wire 3 and the auxiliary tab wire 31.

DESCRIPTION OF SYMBOLS 1 Solar cell module, 2 Solar cell, 2a 1st side edge, 2b 2nd side edge, 3 Tab wire, 4 Strings, 5 matrix, 6 sheet | seat, 7 Surface cover, 8 Back sheet | seat, 9 Metal frame, 10 Photoelectric conversion element, 12 finger electrode, 13 back electrode, 14 tab line connection part, 17 conductive adhesive film, 18 adhesive layer, 20 tab line solar cell, 21 connection part, 23 conductive particle, 24 release substrate , 25 reel, 30 metal pieces, 31 auxiliary tab wire

Claims (10)

A first tab line that is longer than one side of the solar cell is attached to the first surface of the silicon-based solar cell via an adhesive, and one end thereof protrudes from the first side edge of the solar cell. And a second tab wire that is longer than one side of the solar battery cell with an adhesive on the second surface of the solar battery cell, one end of the first solar cell is connected to the first surface of the solar battery cell. Forming a solar cell with a tab line connected to protrude from the second side edge opposite to the side edge,
Arranging a plurality of the above-mentioned tabbed solar cells,
The manufacturing method of the solar cell module which connects the edge part of the said 1st, 2nd tab wire which protruded from the one side edge of the said photovoltaic cell between the said several photovoltaic cell.   The method for manufacturing a solar cell module according to claim 1, wherein ends of the first and second tab wires are connected to each other through a metal piece.   The method for manufacturing a solar cell module according to claim 2, wherein the metal piece has a thickness of 40 to 210 μm. The first and second tab wires are adhesive-attached tab wires in which the adhesive is provided in advance on one surface thereof,
The adhesive in the portion disposed on the solar cell is connected to the solar cell by being cured and the adhesive in the portion protruding from the solar cell is uncured. The manufacturing method of the solar cell module of any one of these.   By collectively bonding the plurality of tab-lined solar cells with the end portions of the first and second tab wires temporarily bonded together with a sealing material, a surface cover and a back sheet by a laminating step, The manufacturing method of the solar cell module of Claim 4 which connects the edge parts of the said tab wire.   Before arranging the said tab line photovoltaic cell, the defect inspection of this photovoltaic cell with a tab line is performed, and the defective photovoltaic cell with a tab line is excluded in advance. Manufacturing method for solar cell module. A plurality of silicon-based solar cells;
A first tab line connected to the first surface of the solar cell, and a second tab line connected to the second surface of the solar cell,
By connecting the first tab line connected to the solar cell and the second tab line connected to the solar cell arranged adjacent to the solar cell, a plurality of tabs are connected. The solar cells are electrically connected,
One end of each of the first and second tab wires protrudes from the side edge of the solar cell, and the protruding portions are connected to each other.   The solar cell module according to claim 7, wherein ends of the tab wires are connected to each other through a metal piece.   The first tab wire, which is longer than one side of the solar battery cell, has an end protruding from the first side edge of the solar battery cell via an adhesive on the first surface of the solar battery cell. The second tab wire, which is longer than one side of the solar battery cell, is attached to the second surface of the solar battery cell via an adhesive, and the one end of the first solar cell is connected to the first surface of the solar battery cell. The solar cell module according to claim 7 or 8, wherein solar cells with tab wires connected so as to protrude from the second side edge opposite to the side edge are arranged.   By collectively bonding the plurality of tab-lined solar cells with the end portions of the first and second tab wires temporarily bonded together with a sealing material, a surface cover and a back sheet by a laminating step, The solar cell module of any one of Claims 7-9 which connects the edge parts of the said tab wire.

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