KR20100135515A - Interconnector and solar cell module having the same - Google Patents

Abstract

PURPOSE: An interconnector and a solar cell module including the same are provided to overcome problems related to a junction failure between the interconnector and a current collector by preventing the reliability of the solar cell module from reducing due to flux residue. CONSTITUTION: A first region(A1) is bonded to a first current collecting part which is arranged the light receiving surface of a solar cell. A second region is bonded to a second current collecting part which is arranged on the opposite part of the light receiving surface. An interconnector(20) includes a conductive metal part and a soldering part. The conductive metal part is based on one selected from copper, aluminum, and silver.

Description

INTERCONNECTOR AND SOLAR CELL MODULE HAVING THE SAME}

The present invention relates to a solar cell module having a plurality of solar cells and an interconnector for electrically connecting the plurality of solar cells.

With the recent prediction of the depletion of existing energy sources such as oil and coal, there is a growing interest in alternative energy to replace them, attracting attention for solar cells that produce electrical energy from solar energy.

A typical solar cell includes a substrate and an emitter layer, each of which is composed of semiconductors of different conductive types, such as p-type and n-type, and electrodes connected to the substrate and the emitter, respectively. At this time, a p-n junction is formed at the interface between the substrate and the emitter portion.

When light is incident on the solar cell, electrons inside the semiconductor become free electrons (hereinafter referred to as electrons) due to a photoelectric effect, and electrons and holes are n in accordance with the principle of pn junction. They move toward the type semiconductor and the p-type semiconductor, for example toward the emitter portion and the substrate. The moved electrons and holes are collected by respective electrodes electrically connected to the substrate and the emitter.

In this case, at least one current collector, such as a bus bar, is formed on the emitter portion and the substrate to connect the electrodes disposed on the emitter portion and the substrate.

Since the voltage and current produced by the solar cell of such a configuration are very small, in order to obtain the desired output, the solar cell module is manufactured by waterproofing in the form of a panel after connecting several solar cells in series or in parallel. use.

In a solar cell module, electrons and holes collected at each current collector, for example, a bus bar, are collected in a junction box provided on the back of the solar cell module, which is connected to electrically connect the plurality of solar cells. Connectors, such as ribbons, are used.

The ribbon is for electrically connecting bus bars formed in each of several solar cells to each other and bonded to the bus bars by flux. Typically, the flux may be applied over the electrode with a width greater than the electrode, or over the electrode with a width less than the electrode, depending on its viscosity.

In the case of the former using a low viscosity flux, it is possible to visually confirm the accuracy of flux application after soldering, but a large amount of flux remains at the interface between the solar cell and the protective film (EVA: Ethylene Vinyl Acetate). Therefore, there is a problem in that the protective film is peeled off or causes electromigration, thereby lowering reliability.

In the case of using a high viscosity flux to solve the problem in the former case, since the flux can be applied in a smaller width than the electrode, there is almost no residue at the interface between the solar cell and the protective film. . However, since it is impossible to visually check the flux coating accuracy, there is a problem in that the application is limited.

The technical problem to be achieved by the present invention is to provide an interconnector that can be effectively used in a solar cell module.

Another object of the present invention is to provide a solar cell module with improved reliability.

An interconnector according to an embodiment of the present invention includes a first region bonded to a first current collector disposed on a light receiving surface of a solar cell; And a second region joined to a second current collector disposed on an opposite side of the light receiving surface, wherein an opening is formed in the first region.

In this case, the widths of the first region and the second region may be the same, and the width of the second region may be larger than the width of the first region. The openings may be formed in both the first region and the second region, and the widths of the first region and the second region may be formed as mentioned above.

The opening is for visually confirming the application accuracy of the flux applied on the current collector to join the interconnector to the current collector, and includes holes formed in the widthwise center of the interconnector, or the interconnector It may include slits formed in a position off the center with respect to the width direction center of the.

In the case of the slit, it is also possible to displace the ones formed on the opposite side from the ones formed on the basis of the widthwise center of the first region.

A protrusion may be formed on the junction surface of the interconnector around the holes or slits, and the protrusion prevents the flux from reflowing out of the current collector by the pressure at the junction of the interconnector and the current collector. do.

The interconnect includes a conductive metal portion and a soldered portion. In this case, the conductive metal part may be formed of any one selected from Cu, Al, and Ag. The soldering portion may be made of any one material selected from SnAg, SnBi, and Sn that does not contain Pb, or may be made of SnPb containing Pb.

The content of the conductive metal portion is higher than that of the solder portion, and the solder portion is coated on the surface of the conductive metal portion.

The interconnector of this configuration is electrically connected to the first electrode located on an emitter of a first conductivity type, a second electrode located on a substrate of a second conductivity type opposite to the first conductivity type, and electrically connected to the first electrode. A solar cell module including solar cells each having a first current collector and a second current collector electrically connected to the second electrode, wherein the first current collector of one solar cell is adjacent to another solar cell. It can be used to electrically connect with the second current collector of the cell.

In this case, the flux is preferably applied to be narrower than the width of the first current collector and the second current collector.

After the junction of the interconnector and the current collector, the holes or slits are filled with a conductive material to suppress an increase in contact resistance of the current collector and the interconnector at the portion where the holes or slits are formed. The conductive material filled in the holes or slits may comprise the same material as the interconnect.

According to another embodiment of the present invention, an interconnector may include a first region bonded to a first current collector disposed on a light receiving surface of a solar cell; And a second region joined to a second current collector disposed on an opposite side of the light receiving surface, wherein the first region and the second region are formed to have different widths. In this embodiment, the opening may be formed only in the first region or both in the first region and the second region. The rest of the configuration may be configured in the same manner as the above-described embodiment.

The interconnector in this configuration comprises a plurality of solar cells; And for electrically connecting the plurality of solar cells.

According to this feature, even if the high viscosity flux is applied smaller than the width of the current collector, positive application accuracy can be visually observed through the opening. Therefore, it is possible to improve the problem caused by poor bonding of the interconnector and the current collector, while preventing the reliability of the solar cell module due to the flux residue.

And since the width | variety of the 2nd area | region joined to the surface opposite the light receiving surface is larger than the 1st area | region, it can improve current collection efficiency.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. When a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case directly above another portion but also the case where there is another portion in between. On the contrary, when a part is "just above" another part, there is no other part in the middle.

An embodiment of the present invention will now be described with reference to the accompanying drawings.

1 is an exploded perspective view of a solar cell module according to an embodiment of the present invention. Referring to FIG. 1, a solar cell module 100 according to an embodiment of the present invention includes a plurality of solar cells 10, an interconnector 20 that electrically connects adjacent solar cells 10, and a solar cell ( 10, a protective film (EVA) 30a, 30b for protecting them, a transparent member 40 disposed on the protective film 30a toward the light receiving surface of the solar cells 10, and a protective film 30b opposite to the light receiving surface. A back sheet 50 disposed below, a frame (not shown) for accommodating the parts integrated by a lamination process, and a junction for finally collecting current and voltage produced in the solar cells 10. And a junction box 60.

Here, the back sheet 50 prevents moisture from penetrating at the back of the solar cell module 10 to protect the solar cell 10 from the external environment. The back sheet 50 may have a multilayer structure such as a layer for preventing moisture and oxygen penetration, a layer for preventing chemical corrosion, and a layer having insulation properties.

The passivation layers 30a and 30b are integrated with the solar cells 10 by a lamination process in a state in which the protective layers 30a and 30b are respectively disposed on the upper and lower portions of the solar cells 10. To protect against shock. The passivation layers 30a and 30b may be made of a material such as ethylene vinyl acetate (EVA).

The transparent member 40 positioned on the upper protective film 30a is made of tempered glass having a high transmittance and excellent breakage preventing function. In this case, the tempered glass may be a low iron tempered glass having a low iron content. The transparent member 40 may be embossed with an inner surface to increase the light scattering effect.

The solar cell module 100 includes the steps of testing the solar cell 10, electrically connecting the plurality of tested solar cells 10 by the interconnector 20, and sequentially connecting the components, for example, the lower part. Disposing the back sheet 50, the lower passivation film 30b, the solar cells 10, the upper passivation film 30a, and the transparent member 40 in this order, and performing the lamination process in a vacuum state to integrate the components. It is manufactured according to the process sequence such as the step of doing, the edge trimming step and the step of performing the module test.

FIG. 2 is a perspective view of the solar cell shown in FIG. 1. FIG. Referring to FIG. 2, the solar cell 10 includes a substrate 11, an emitter part 12 positioned on the light receiving surface of the substrate 11 on which light is incident, and a plurality of first emitters positioned on the emitter part 12. At least one first current collector 14, first electrode 13, and first current collector 14 positioned on the emitter portion 12 in a direction crossing the electrode 13 and the first electrode 13. The anti-reflective film 15 positioned on the emitter portion 12 where the light is not positioned, the second electrode 16 positioned on the opposite side of the light-receiving surface, and the second current collector 17 positioned on the second electrode 16. Include.

The solar cell 10 may further include a back surface field (BSF) portion formed between the second electrode 16 and the substrate 11. The backside electric field is a region in which impurities of the same conductivity type as the substrate 11 are doped at a higher concentration than the substrate 11, for example, a p + region.

This backside electric field acts as a substrate 11 potential barrier. Therefore, the recombination and dissipation of electrons and holes at the rear side of the substrate 11 are reduced, so that the efficiency of the solar cell is improved.

The substrate 11 is a semiconductor substrate made of silicon of a first conductivity type, for example a p-type conductivity type. In this case, the silicon may be monocrystalline silicon, polycrystalline silicon, or amorphous silicon. When the substrate 11 has a p-type conductivity type, it contains impurities of trivalent elements such as boron (B), gallium (Ga), indium (In), and the like.

The substrate 11 may be texturized to form a surface of the substrate 11 as a textured surface that is an uneven surface. When the surface of the substrate 11 is formed as a texturing surface, the light reflectance at the light receiving surface of the substrate 11 is reduced, and incident and reflection operations are performed on the texturing surface to trap light in the solar cell, thereby increasing light absorption. . Thus, the efficiency of the solar cell is improved. In addition, the reflection loss of light incident on the substrate 11 is reduced, so that the amount of light incident on the substrate 11 is further increased.

The emitter portion 12 is a region doped with impurities having a second conductivity type, for example, an n-type conductivity type, which is opposite to the conductivity type of the substrate 11. pn junction. When the emitter portion 12 has an n-type conductivity type, the emitter portion 12 may be doped with impurities of a pentavalent element such as phosphorus (P), arsenic (As), antimony (Sb), and the like on the substrate 11. Can be formed.

Accordingly, when electrons in the semiconductor receive energy by light incident on the substrate 11, the electrons move toward the n-type semiconductor and the holes move toward the p-type semiconductor. Therefore, when the substrate 11 is p-type and the emitter portion 12 is n-type, the separated holes move toward the substrate 11 and the separated electrons move toward the emitter portion 12.

In contrast, the substrate 11 may be of an n-type conductivity type, and may be made of a semiconductor material other than silicon. When the substrate 11 has an n-type conductivity type, the substrate 11 may contain impurities of pentavalent elements such as phosphorus (P), arsenic (As), and antimony (Sb).

Since the emitter portion 12 forms a p-n junction with the substrate 11, when the substrate 11 has an n-type conductivity type, the emitter portion 12 has a p-type conductivity type. In this case, the separated electrons move toward the substrate 11 and the separated holes move toward the emitter portion 12.

When the emitter portion 12 has a p-type conductivity type, the emitter portion 12 may dopant impurities of trivalent elements such as boron (B), gallium (Ga), indium (In), and the like onto the substrate 11. Can be formed.

On the emitter portion 12 of the substrate 11, an antireflection film 15 made of a silicon nitride film SiNx, a silicon oxide film SiO ₂ , or the like is formed. The anti-reflection film 15 reduces the reflectivity of light incident on the solar cell 10 and increases the selectivity of a specific wavelength region to increase the efficiency of the solar cell 10. The anti-reflection film 15 may have a thickness of about 70 nm to 80 nm, and may be omitted as necessary.

The plurality of first electrodes 13 are formed on the emitter part 12 to be electrically connected to the emitter part 12, and are formed in one direction in a state of being spaced apart from the adjacent first electrode 13. Each first electrode 13 collects charges, for example, electrons, which are moved toward the emitter part 12, and transfers them to the first current collector 15.

The plurality of first electrodes 13 is made of at least one conductive material, and the conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), and zinc (Zn). ), At least one selected from the group consisting of indium (In), titanium (Ti), gold (Au), and combinations thereof, but may be formed of another conductive metal material.

The plurality of first current collectors 14 are positioned on the emitter portion 12. The first current collector 14, also called a bus bar, is formed in a direction crossing the first electrode 13. Therefore, the first electrode 13 and the first current collector 14 are arranged in such a manner as to intersect on the emitter portion 12.

The first current collector 14 is also made of at least one conductive material and is connected to the emitter portion 12 and the first electrode 13. Accordingly, the first current collector 14 outputs the electric charge, for example, electrons transferred from the first electrode 13 to the external device.

The conductive metal materials constituting the first current collector 14 include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), and titanium. It may be at least one selected from the group consisting of (Ti), gold (Au), and combinations thereof, but may be made of another conductive metal material. In the present exemplary embodiment, the plurality of first current collectors 14 include the same material as the first electrode 13, but may include different materials.

The first electrode 13 and the first current collector 14 are coated with a conductive metal material on the anti-reflection film 15, and then patterned in the form shown in FIG. 2, and then electrically connected to the emitter unit 12 in the process of firing. Can be connected.

The second electrode 16 is formed on the opposite side of the light receiving surface of the substrate 11, that is, on the lower surface of the substrate 11, and collects charges, for example, holes, moving toward the substrate 11.

The second electrode 16 is made of at least one conductive material. Conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au) and their It may be at least one selected from the group consisting of a combination, but may be made of other conductive materials.

A plurality of second current collectors 17 is positioned below the second electrode 16. The second current collector 17 is formed in a direction crossing the first electrode 13, that is, in a direction parallel to the first current collector 14.

The second current collector 17 is also made of at least one conductive material and is electrically connected to the second electrode 16. Accordingly, the second current collector 17 outputs electric charges, for example, holes, transferred from the second electrode 16 to the external device.

The conductive metal materials constituting the second current collector 17 include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), and titanium. It may be at least one selected from the group consisting of (Ti), gold (Au), and combinations thereof, but may be made of another conductive metal material.

Operation of the solar cell 10 according to the present embodiment having such a structure is as follows.

When light is irradiated to the solar cell 10 and incident on the substrate 11 through the antireflection film 15 and the emitter part 12, free electrons are generated by a photoelectric effect, and pn According to the principle of bonding, electrons move toward the emitter portion 12 having an n-type conductivity type, and holes move toward the substrate 11 having a p-type conductivity type. As such, the electrons moved toward the emitter portion 12 are collected by the first electrode 13 and moved to the first current collector 14, and the holes moved toward the substrate 11 are moved by the second electrode 16. Collected and moved to the second current collector 17.

The solar cell 10 may be used alone, but for more efficient use, a plurality of solar cells 10 having the same structure are connected in series to form a solar cell module.

Subsequently, an electrical connection structure of the solar cell module according to the embodiment of the present invention will be described with reference to the accompanying drawings.

Figure 3 is a side view showing the electrical connection structure of the solar cell, Figures 4a and 4b is a perspective view showing an interconnector according to an embodiment of the present invention, Figures 5a and 5b is a side view of the interconnector according to an embodiment of the present invention to be. 6 is a perspective view illustrating an interconnector according to another embodiment of the present invention, and FIGS. 7A to 67C are side cross-sectional views illustrating a process of joining an interconnector and a current collector.

The plurality of solar cells 10 are arranged in a matrix structure as shown in FIG. 1. In FIG. 1, the solar cells 10 arranged on the lower passivation layer 30b have a 3 × 3 matrix structure, but are not limited thereto, and the number of the solar cells 10 arranged in the row and column directions as needed is adjusted. This is possible.

The plurality of solar cells 10 are electrically connected by interconnectors 20 as shown in FIG. 3. More specifically, in a state in which the plurality of solar cells 10 are disposed adjacent to each other, the first current collector 14 of one solar cell is connected by the second current collector 17 and the interconnector 20 of the adjacent solar cell. Electrically connected.

The interconnector 20 includes a first region A1 joined to the first current collector 14 and a second region A2 joined to the second current collector 17.

Referring to FIGS. 4A and 4B, the first region A1 may have an opening for visually observing the application accuracy of the high viscosity flux F applied on the first current collector 14, for example, The hole H or the slit S is provided. According to this configuration, when the interconnector 20 is connected to the current collector using the high viscosity flux F, the flux application accuracy can be visually confirmed through the hole H or the slit S. .

The holes H may be formed in a polygonal shape including a circle, an ellipse, or a quadrangle, and a plurality of holes H may be formed along the widthwise center C-C of the first area A1 (see FIG. 4A).

Alternatively, the slit S is outside the widthwise center CC of the first region A1 to disperse the region where the interconnector 20 and the first current collector 14 are not bonded to improve the bonding strength. Plural can be formed at the position. And, based on the widthwise center C-C, those formed on one side and those formed on the opposite side may be disposed to be offset from each other (see FIG. 4B).

On the other hand, the hole H and the slit S can also be formed in the 2nd area | region A2 as shown with the dotted line in FIGS. 4A and 4B.

Referring to FIGS. 7A to 7C, the holes H and the slits S may include protrusions P. Referring to FIGS. The protrusion P prevents the flux F from reflowing out of the first current collector 14 by the pressure when the interconnector 20 and the first current collector 14 are joined. For the purpose, it is formed on the bonding surface of the interconnector 20, that is, the surface facing the current collector.

According to this structure, when the interconnector 20 is joined to the current collector, the flux F applied to the center of the first current collector is filled in the hole H or the slit S. Therefore, since the flux F is prevented from reflowing to the outer side of the current collector 14, problems due to the residual flux can be suppressed.

On the other hand, after completing the bonding of the interconnector 20 and the current collector, the empty hole H or the slit S is filled with the same material as that of the conductive material 22, for example, the interconnector 20. In addition, the contact resistance generated at the contact portion of the interconnector 20 and the current collector may be reduced.

Referring to FIGS. 5A and 5B, the interconnector 20 includes a conductive metal portion 22 and a soldered portion 24. The soldering part 24 may be coated only on the upper and lower surfaces of the conductive metal part 22 or may be coated on the entire surface of the conductive metal part 22.

The conductive metal part may be made of any one material of excellent conductivity, Cu, Al, and Ag. And, the soldering portion may be made of SnPb containing Pb. Of course, in order to prevent environmental pollution, the soldering portion may be made of any one material selected from Sn, SnAg, and SnBi that are free of Pb-free, such as Pb. In the interconnector, the content of the conductive metal portion is higher than that of the solder portion.

Referring to FIG. 6, the interconnector 20 includes a first area A1 and a second area A2 having a larger width than this area. In this case, the second current collector 17 may be formed to have a large width similarly to the second area A2 of the interconnector 20. That is, the second current collector 17 may be formed to have a larger width than the width of the first current collector 14, which is located opposite the light receiving surface of the substrate 11 in the case of the second current collector 17. This is because the width can be increased irrespective of the light receiving area. According to this configuration, since the resistance is reduced due to the increase in the width of the second region A2, the current collecting efficiency can be improved. And, the hole H or the slit S having the same configuration as in the above-described embodiment is formed in the first area A1 of the interconnector 20 as shown by the dotted line in FIG. 6, or the first area ( It may be formed in A1) and the second region A2.

Meanwhile, the first area A1 of the interconnector 20 may be formed as a textured surface whose surface in the direction in which light is incident is an uneven surface. According to the texturing surface of the first region A1, an effect similar to the texturing effect of the substrate 11 may be obtained.

By this interconnector 20, a plurality of solar cells 10 arranged in the solar cell module 100 are connected in series, and the current and voltage produced in the solar cells 10 finally reach the junction box 60. Are collected).

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is an exploded perspective view of a solar cell module according to an embodiment of the present invention.

FIG. 2 is a partial perspective view of the solar cell shown in FIG. 1. FIG.

3 is a side view illustrating an electrical connection structure between the solar cells illustrated in FIG. 1.

4A and 4B are perspective views illustrating an interconnector according to one embodiment of the present invention.

5A and 5B are side views of interconnectors in accordance with embodiments of the present invention.

6 is a perspective view illustrating an interconnector according to another embodiment of the present invention.

7A to 7C are side cross-sectional views illustrating a bonding process of an interconnector and a current collector.

Brief description of the main parts of the drawing

10: solar cell 11: substrate

12: emitter portion 13: first electrode

14: first current collector 15: antireflection film

16: second electrode 17: second current collector

20: interconnector 30a, 30b: protective film

40: transparent member 50: back sheet

60: junction box

Claims (54)

A first region bonded to the first current collector disposed on the light receiving surface of the solar cell; And A second region bonded to a second current collector disposed on an opposite surface of the light receiving surface Including; And an opening is formed in the first region. In claim 1, The interconnector is formed to have the same width of the first region and the second region. In claim 1, The width of the second region is greater than the width of the first region. In claim 1, The opening is formed in the first region and the second region. In claim 4, The interconnector is formed to have the same width of the first region and the second region. In claim 4, The width of the second region is greater than the width of the first region. In any one of claims 1 to 6, And the opening includes holes formed in a widthwise center of the interconnector. In claim 7, An interconnecting portion is formed in a joining surface of the interconnector around the holes. In any one of claims 1 to 6, And the opening includes slits formed at a position off the center with respect to the widthwise center of the interconnector. The method of claim 9, And wherein the slits are arranged to be offset from each other on the opposite side of the slits based on the width center of the interconnector. The method of claim 9, An interconnecting portion formed in a joining surface of the interconnector around the slits. A first region bonded to the first current collector disposed on the light receiving surface of the solar cell; And A second region bonded to a second current collector disposed on an opposite surface of the light receiving surface Including; And the first region and the second region have different widths. In claim 12, And an opening is formed in the first region. In claim 12, And an opening is formed in the first region and the second region. The method of claim 13 or 14, And the opening includes holes formed in a widthwise center of the interconnector. 16. The method of claim 15, An interconnecting portion is formed in a joining surface of the interconnector around the holes. The method of claim 13 or 14, And the opening includes slits formed at a position off the center with respect to the widthwise center of the interconnector. The method of claim 17, And wherein the slits are arranged to be offset from each other on the opposite side of the slits based on the width center of the interconnector. The method of claim 17, An interconnection formed around a surface of the slits in a joining surface of the interconnector. A first electrode located on an emitter of a first conductivity type, a second electrode located on a substrate of a second conductivity type opposite to the first conductivity type, a first current collector electrically connected to the first electrode, and Solar cells each having a second current collector electrically connected to a second electrode; And Interconnect electrically connecting the first current collector of one solar cell with the second current collector of another solar cell adjacently disposed And, The interconnector includes a first region bonded to the first current collector and a second region bonded to the second current collector, and an opening is formed in the first region. The method of claim 20, The first region and the second region are respectively bonded to the first current collector and the second current collector by flux, and the flux is applied to be narrower than the width of the first current collector and the second current collector. The method of claim 21, The solar cell module having a width of the first region and the second region are the same. The method of claim 21, The width of the second region is greater than the width of the first region of the solar cell module. The method of claim 21, The opening is formed in the first region and the second region. The method of claim 24, The interconnector is formed to have the same width of the first region and the second region. The method of claim 24, The width of the second region is greater than the width of the first region. 27. The method of any of claims 20 to 26, The interconnector comprises a conductive metal portion and a soldered portion. The method of claim 27, The conductive metal part is an interconnector made of any one selected from Cu, Al and Ag. The method of claim 27, The soldering portion is made of any one material selected from SnAg, SnBi and Sn that does not contain Pb, or an interconnector consisting of SnPb containing Pb. The method of claim 27, And the content of the conductive metal portion is greater than that of the solder portion. The method of claim 27, The soldering portion is coated on a surface of the conductive metal portion. The method of claim 27, And the opening includes holes formed in a widthwise center of the interconnector. The method of claim 32, A solar cell module having a protrusion formed at a junction surface of the interconnector around the holes. The method of claim 32, The solar cell module is filled with a conductive material inside the holes. The method of claim 27, The opening includes a slit (slit) formed in a position off the center with respect to the widthwise center of the interconnector. 36. The method of claim 35 wherein And the slits are arranged to be offset from each other and formed on the opposite side of the slits based on the widthwise center of the interconnector. 36. The method of claim 35 wherein A solar cell module having a protrusion formed at a junction surface of the interconnector around the slits. 36. The method of claim 35 wherein A solar cell module filled with a conductive material inside the slits. A plurality of solar cells; And An interconnector for electrically connecting the plurality of solar cells And, And wherein the interconnector has a variable width that varies in width along its length direction. The method of claim 39, The interconnector includes a first region having a relatively narrow width and a second region having a larger width than the first region. 41. The method of claim 40 wherein And the first region comprises an opening. 41. The method of claim 40 wherein And the first region and the second region comprise openings. 43. The method of any of claims 39-42, The interconnector comprises a conductive metal portion and a soldered portion. The method of claim 43, The conductive metal part is an interconnector made of any one selected from Cu, Al and Ag. The method of claim 43, The soldering portion is made of any one material selected from SnAg, SnBi and Sn that does not contain Pb, or an interconnector consisting of SnPb containing Pb. The method of claim 43, And the content of the conductive metal portion is greater than that of the solder portion. The method of claim 43, The soldering portion is coated on a surface of the conductive metal portion. The method of claim 43, And the opening includes holes formed in a widthwise center of the interconnector. The method of claim 43, A solar cell module having a protrusion formed at a junction surface of the interconnector around the holes. The method of claim 43, The solar cell module is filled with a conductive material inside the holes. The method of claim 43, The opening includes a slit (slit) formed in a position off the center with respect to the widthwise center of the interconnector. The method of claim 51, And the slits are arranged to be offset from each other and formed on the opposite side of the slits based on the widthwise center of the interconnector. The method of claim 51, A solar cell module having a protrusion formed at a junction surface of the interconnector around the slits. The method of claim 51, A solar cell module filled with a conductive material inside the slits.

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