KR102665568B1 - Solar cell panel - Google Patents

Abstract

In the solar cell panel according to an embodiment of the present invention, the first electrode of the first solar cell and the second electrode of the second solar cell positioned so as to have an adjacent portion on the front surface thereof are connected by a connection sheet containing a plurality of wiring members. do.

Description

Solar cell panel {SOLAR CELL PANEL}

The present invention relates to a solar cell panel, and more specifically, to a solar cell panel with an improved connection structure of solar cells.

A plurality of solar cells are connected in series or parallel, and are manufactured in the form of a solar cell panel through a packaging process to protect the plurality of solar cells.

A variety of structures can be applied as a structure for connecting solar cells. As an example, parts of neighboring solar cells are overlapped to form a narrow and long overlapping part, and a narrow width and long conductive adhesive (ECA) is applied to the overlapping part between neighboring solar cells. It can be positioned. According to this structure, more solar cells can be placed in the solar panel, which may be advantageous to the efficiency of the solar panel.

However, since the conductive adhesive layer is a material that requires caution when handling, the stability of the manufacturing process may be reduced and the high price may reduce productivity. In addition, the manufacturing process is complicated because a process of aligning and attaching a plurality of solar cells and a conductive adhesive layer for connecting them must be performed. In particular, in the case of a cut solar cell that is cut from the mother solar cell so that each solar cell has a long axis and a short axis, a conductive adhesive layer is formed on the mother solar cell to correspond to each cut solar cell, and the mother solar cell is cut to cut the solar cell. A cell is formed, and the cut solar cells are then attached using a conductive adhesive layer. Accordingly, the manufacturing process is very complicated and defects can easily occur, resulting in low yield. Accordingly, the productivity of solar cells with a connection structure using overlapping portions was not excellent.

In another prior art, as in U.S. Patent Publication No. 2017/0085217, in a solar cell connection structure using an overlap, an electrode located in the overlap of one solar cell and a pad located on the back of a neighboring solar cell are connected as an interconnector. There is a technology to connect. In this connection structure, the interconnector was located only in the overlapping area and at the rear, making it difficult to efficiently collect and transmit carriers. Additionally, problems such as unwanted shunting and damage to the solar cell may occur if the interconnector unintentionally contacts parts other than the overlapping area and the pad area. If the interconnector is bent or folded to prevent this, damage or defects in the interconnector may occur and structural stability may be reduced.

Another conventional technique is to connect adjacent cut solar cells by individually placing wiring members with a certain width in the overlapping portion. In this connection structure, in order to prevent problems such as stress being applied to the cut solar cell by the wiring member or damage to the wiring member by the cut solar cell, the width or diameter of the wiring member and the conditions of the attachment process of the solar cell and the wiring member are adjusted. The back must be precisely adjusted. Accordingly, technology that can further improve the reliability and productivity of solar cell panels is required.

U.S. Patent Publication No. 2017/0085217 (Title of the invention: High-efficiency structure for solar cell strings)

The present invention seeks to provide a solar cell panel that can improve output and improve productivity and reliability.

Here, the present invention can improve output and efficiency per unit area by applying a structure that minimizes the distance between neighboring solar cells, while simplifying the manufacturing process by not using a conductive adhesive layer, improving the stability of the manufacturing process, and improving cost. We would like to provide a solar panel that can save money. In addition, by using a connection sheet with multiple wiring members embedded in the connection structure where adjacent parts and wiring materials are applied, structural stability is improved to provide a solar panel that can minimize undesired stress on solar cells and wiring materials. I want to do it.

A solar cell panel according to an embodiment of the present invention has a first electrode of a first solar cell and a second electrode of a second solar cell positioned to have an adjacent portion that contacts or overlaps the front surface of the first solar cell and includes a plurality of wiring members. are electrically connected by an embedded connection sheet. For example, a plurality of wiring members may be formed extending from the front side of the first solar cell, adjacent portions, and the back side of the second solar cell. The connection sheet may be a connection film containing a conductor, a connection member, a connection layer, an interconnector sheet, an interconnector film, an interconnector member, an interconnector layer, etc. For example, the connection sheet with built-in wiring material may be a resin film or resin layer provided with wiring or interconnectors. Wiring materials may have various shapes or structures, such as wires, ribbons, connecting members, and interconnectors. A plurality of solar cells including first and second solar cells each include a semiconductor substrate, and the first electrode is located on the front side of the semiconductor substrate and the second electrode is located on the back side of the semiconductor substrate.

The first and second solar cells may each have a major axis and a minor axis. In the connection sheet, a plurality of wiring members may extend in a minor axis direction parallel to the first direction and may be positioned to be spaced apart from each other in a second direction intersecting the first direction.

The connection sheet may include an insulating portion integrated with a plurality of wiring members to physically secure the plurality of wiring members.

The insulating portion includes a first insulating portion located on at least the front surface of the first solar cell, and a second insulating portion located on at least the rear surface of the second solar cell, and the first insulating portion is located on the front side of the plurality of wiring members. and the second insulating portion may be located on the rear side of the plurality of wiring members. The connection sheet may have an adjacent portion where the first insulating portion and the second insulating portion are in contact with or overlap with each other, corresponding to the adjacent portion.

A portion of the rear surface of the second solar cell may be located on the front surface of the first solar cell to form an overlapping portion that extends long in the long axis direction. The connection sheet may have an overlapping portion where the first insulating portion and the second insulating portion overlap each other corresponding to the overlapping portion. An overlapping portion of the connection sheet may be located between the first and second solar cells in the overlapping portion.

A plurality of wiring members may be spaced apart from each other in a second direction intersecting the first direction within the insulating portion and may be spaced apart from the first and second solar cells.

The first electrode may include a plurality of first finger lines extending long in the major axis direction, and a plurality of wiring members may be positioned to extend in the minor axis direction and pass through the plurality of first finger lines of the first solar cell.

A plurality of wiring members may extend from the back of the second solar cell to a portion other than the adjacent portion and be connected to the second electrode. For example, the second electrode may include a plurality of second finger lines extending long in the major axis direction, and the second extension portion may be positioned to extend in the minor axis direction and pass through the plurality of second finger lines of the second solar cell. there is.

The connection sheet and the plurality of wiring members may extend long from one side of the front side of the first solar cell, which is opposite to the adjacent portion, to the other side of the rear side of the second solar cell, which is opposite to the adjacent portion. For example, the connection sheet and the plurality of wiring members may not each have a portion that is bent or bent at an acute angle from one side of the front of the first solar cell to the other side of the rear of the second solar cell.

In the thickness direction of the first or second solar cell, the positional difference between the connection sheet or the plurality of wiring members may be smaller than the thickness of the first or second solar cell.

At least one of the first and second electrodes may include a plurality of finger lines formed in a second direction crossing the first direction, and the width or diameter of the wiring member may be smaller than the pitch of the plurality of finger lines.

A plurality of wiring members built into the connection sheet may each have a width or diameter of 400 μm or less and be spaced apart from each other in a second direction intersecting the first direction, and may be located in 4 to 24 numbers.

A portion of the rear surface of the second solar cell is located on the front surface of the first solar cell to form an overlapping part extending long in the major axis direction, and the width, diameter, or thickness of the wiring material may be smaller than the width of the overlapping part in the minor axis direction.

The width of the overlapping portion in the minor axis direction may be 2 mm or less. The distance between the first solar cell and the second solar cell located in the overlap portion in the thickness direction or the thickness of the connection sheet may be smaller than the width of the overlap portion in the minor axis direction.

In one embodiment, the connection sheet may further include pad electrodes extending in a direction that intersects the plurality of wiring members corresponding to adjacent portions. The line width of the pad electrode may be equal to or greater than the width or diameter of the wiring member, and the thickness of the pad electrode may be equal to or greater than the thickness or diameter of the wiring member.

According to this embodiment, the number of solar cells included in a solar cell panel and the area where the solar cells are located can be maximized by applying a structure that minimizes the distance between solar cells. As a result, the output of the solar cell panel can be improved and the efficiency per unit area can be improved. At this time, the manufacturing process can be simplified, the stability of the manufacturing process can be improved, and the cost can be reduced by not using a conductive adhesive layer. In addition, by using a connection sheet with a plurality of wiring members embedded in a connection structure using adjacent portions (eg, overlapping portions) and wiring materials, the manufacturing process can be further simplified and stress applied to the solar cell can be reduced. As a result, the stability of the solar cell connection structure can be improved, thereby improving the productivity and reliability of the solar cell panel.

1 is a perspective view schematically showing a solar cell panel according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. 1.
Figure 3 is a plan view showing two solar cells formed by cutting one mother solar cell according to an embodiment of the present invention.
FIG. 4 is a partial cross-sectional view showing a solar cell and a connection sheet attached thereto along line IV-IV of FIG. 3.
FIG. 5 is a plan view schematically showing a plurality of solar cells included in the solar cell panel shown in FIG. 1 and connected by a connection sheet including a plurality of wiring members.
FIG. 6 is a perspective view schematically showing a connection sheet including a plurality of wiring members shown in FIG. 5.
FIG. 7 is a partial cross-sectional view showing first and second solar cells and a connection sheet at an overlapping portion of the first and second solar cells included in the solar cell panel shown in FIG. 1.
Figure 8 is a plan view showing a plurality of solar cells formed by cutting one mother solar cell according to a modified example of the present invention.
Figure 9 is a plan view schematically showing a plurality of solar cells included in a solar cell panel according to another modified example of the present invention and connected by a connection sheet.
FIG. 10 is a partial cross-sectional view showing various examples of a connection structure using a connection sheet at an overlapping portion of the first and second solar cells in a solar cell panel according to another embodiment of the present invention.
FIG. 11 is a partial cross-sectional view showing various examples of a connection structure using a connection sheet at an overlapping portion of the first and second solar cells in a solar cell panel according to another embodiment of the present invention.
Figure 12 is a perspective view schematically showing a connection sheet included in a solar cell panel according to another embodiment of the present invention and including a plurality of wiring members connecting first and second solar cells.
FIG. 13 is a partial cross-sectional view showing various examples of the connection sheet shown in FIG. 12.
Figure 14 is a plan view showing two solar cells formed by cutting one mother solar cell according to another embodiment of the present invention.
Figure 15 is a plan view showing two solar cells formed by cutting one mother solar cell according to another embodiment of the present invention.
Figure 16 is a partial cross-sectional view schematically showing a plurality of solar cells and connection sheets included in a solar cell panel according to another embodiment of the present invention.
Figure 17 is a partial cross-sectional view schematically showing a plurality of solar cells and connection sheets included in a solar cell panel according to another modified example of the present invention.
Figure 18 is a perspective view schematically showing a solar cell panel according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, it goes without saying that the present invention is not limited to these embodiments and can be modified into various forms.

In the drawings, in order to clearly and briefly explain the present invention, parts not related to the description are omitted, and identical or extremely similar parts are denoted by the same drawing reference numerals throughout the specification. In addition, in the drawings, the thickness, area, etc. are enlarged or reduced in order to make the explanation more clear, so the thickness, area, etc. of the present invention are not limited to what is shown in the drawings.

And when a part is said to “include” another part throughout the specification, it does not exclude other parts and may further include other parts, unless specifically stated to the contrary. Additionally, when a part of a layer, membrane, region, plate, etc. is said to be “on” another part, this includes not only cases where it is “directly above” the other part, but also cases where other parts are located in between. When a part of a layer, membrane, region, plate, etc. is said to be "directly on top" of another part, it means that the other part is not located in the middle.

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

FIG. 1 is a perspective view schematically showing a solar cell panel according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line II-II of FIG. 1. For simplicity of illustration, the wiring member 142 connecting a plurality of solar cells 10 is shown only in the enlarged view of FIG. 1 , and the number of solar cells 10 is shown differently in FIGS. 1 and 2 .

Referring to FIGS. 1 and 2, the solar cell panel 100 according to this embodiment includes first and second solar cells 10a and 10b connected to each other in a first direction (x-axis direction of the drawing). A connection sheet 140 is provided with a plurality of solar cells 10 and a plurality of wiring members 142 that electrically connect the first and second solar cells 10a and 10b. More specifically, the first and second solar cells 10a and 10b each have a semiconductor substrate (reference numeral 12 in FIG. 4, hereinafter the same) and a first electrode (in FIG. 4) located on the front side of the semiconductor substrate 12. They each include a second electrode (reference numeral 44 in FIG. 4, the same hereinafter) located on the rear side of the semiconductor substrate 12. At this time, the rear surface of the second solar cell 10b may be positioned above the front surface of the first solar cell 10a and may be positioned so as to have an adjacent portion that contacts or overlaps the first solar cell 10a. The plurality of wiring members 142 built into the connection sheet 140 extend in a first direction to connect the first electrode 42 of the first solar cell 10a and the second electrode 44 of the second solar cell 10b. Connect. And the solar cell panel 100 includes a sealing material 130 that surrounds and seals the plurality of solar cells 10, and a first cover member (front member) located on the front surface of the solar cell 10 on the sealing material 130. It may further include 110 and a second cover member (rear member) 120 positioned on the rear surface of the solar cell 10 above the sealant 130 . This will be explained in more detail.

First, the solar cell 10 may include a photoelectric conversion unit that converts the solar cell into electrical energy, and electrodes 42 and 44 that are electrically connected to the photoelectric conversion unit to collect and transmit current. The solar cell 10 will be described in more detail later. The plurality of solar cells 10 may be electrically connected in series, parallel, or series-parallel by the connection sheet 140 including the wiring member 142. A plurality of wiring members 142 included in the connection sheet 140 extend to the front of the first solar cell 10a, the adjacent portion (eg, overlapping portion OP), and the rear of the second solar cell 10b. can be formed. As an example, the wiring member 142 of the connection sheet 140 connects adjacent first and second solar cells 10a and 10b among the plurality of solar cells 10 in series, and this connection is repeated to form one row. A solar cell string (S) forming a (列) can be configured.

In addition, the bus ribbon 145 may be connected to the wiring member 142 provided on the connection sheet 140 and connected to both ends of the solar cell string (S). The bus ribbon 145 may be disposed at an end of the solar cell string S in a direction that intersects therewith (i.e., the second direction (y-axis direction in the drawing)). This bus ribbon 145 connects adjacent solar cell strings (S) in series, parallel, or series-parallel, or connects the solar cell strings (S) to a junction box (not shown) that prevents reverse flow of current. You can. The material, shape, connection structure, etc. of the bus ribbon 145 may be modified in various ways, and the present invention is not limited thereto.

The sealing material 130 may include first and second sealing materials 131 and 132 respectively located on the front and rear surfaces of the solar cell 10 connected by the connection sheet 140 including the wiring material 142. . The first sealing material 131 and the second sealing material 132 prevent moisture and oxygen from entering and chemically bond each element of the solar cell panel 100. The first and second sealing materials 131 and 132 may be made of an insulating material that is transparent and adhesive. As an example, ethylene vinyl acetate copolymer resin (EVA), polyvinyl butyral, silicon resin, ester resin, olefin resin, etc. may be used as the first sealant 131 and the second sealant 132. By a lamination process using the first and second sealants 131 and 132, the second cover member 120, the second sealant 132, the solar cell 10, the first sealant 131, and the first cover member ( 110) may be integrated to form the solar cell panel 100.

The first cover member 110 is located on the first sealant 131 and forms the front of the solar cell panel 100, and the second cover member 120 is located on the second sealant 132 to form the solar cell. Constructs the rear of the panel 100. The first cover member 110 and the second cover member 120 may each be made of an insulating material capable of protecting the solar cell 10 from external shock, moisture, ultraviolet rays, etc. The first cover member 110 may be made of a translucent material that allows light to pass through, and the second cover member 120 may be made of a sheet made of a translucent material, a non-transmissive material, or a reflective material. For example, the first cover member 110 may be composed of a glass substrate, etc., and the second cover member 120 may have a TPT (Tedlar/PET/Tedlar) type, or a base film (e.g., polyethylene). It may include a polyvinylidene fluoride (PVDF) resin layer formed on at least one side of terephthalate (PET).

However, the present invention is not limited to this. Accordingly, the first and second sealants 131 and 132, the first cover member 110, or the second cover member 120 may include various materials other than those described above and may have various shapes. For example, the first cover member 110 or the second cover member 120 may have various forms (eg, substrates, films, sheets, etc.) or materials.

The solar cell 10 and the wiring member 142 connected thereto according to an embodiment of the present invention will be described in more detail with reference to FIGS. 3 and 4 along with FIG. 2 . Figure 3 shows two solar cells 10 (for example, first and second solar cells 10a and 10b) formed by cutting one mother solar cell 100a according to an embodiment of the present invention. It is a plan view, and FIG. 4 is a partial cross-sectional view showing the solar cell 10 and the connection sheet 140 attached thereto taken along line IV-IV of FIG. 3. For simplification and clear understanding, FIG. 3 mainly shows the semiconductor substrate 12 and the first and second electrodes 42 and 44.

Referring to FIGS. 1 to 4 , the mother solar cell 100a according to this embodiment includes a plurality of solar cells 10 cut by a cutting line CL. When the mother solar cell 100a is cut along the cutting line CL, a plurality of solar cells 10 are manufactured, and each solar cell 10 manufactured in this way functions as one solar cell.

In the drawings and the following description, for convenience, the overall cutting line CL is positioned to extend long along the center of the mother solar cell 100a, so that two solar cells 10 are manufactured from one mother solar cell 100a. This was exemplified. According to this, an active area (AA) in which conductive regions 20 and 30 and first and second electrodes 42 and 44 are located corresponding to each solar cell 10 is located in the mother solar cell 100a, These active areas (AA) are spaced apart from each other with the separation area 14 in between. At the edge of each solar cell 10, a non-active area (NA) in which the conductive areas 20 and 30 and/or the first and second electrodes 42 and 44 are not located is located, and the non-active area (NA) ), the separation area 14 is located at the edge adjacent to the cutting surface CL. In the isolation region 14, the conductive regions 20, 30 and/or the first and second electrodes 42, 44 may not have been formed when the mother solar cell 100a was manufactured, or may have been formed during the cutting step. The conductive regions 20, 30 and/or the first and second electrodes 42, 44 disappear in the vicinity of the cutting line CL, or another layer is formed in the vicinity of the cutting line CL, thereby forming a separation region 14. ) may be formed. However, the present invention is not limited to this, and various modifications are possible, such as not providing a separate separation area 14, etc. Additionally, one mother solar cell 100a may have two or more separation regions 14 or cutting lines CL, so that three or more solar cells 10 may be manufactured from one mother solar cell 100a. This will be explained in more detail later with reference to FIG. 8.

In this embodiment, the solar cell 10 includes a semiconductor substrate 12 including a base region 12a, conductive regions 20 and 30 formed in or on the semiconductor substrate 12, and , and includes electrodes 42 and 44 connected to the conductive regions 20 and 30. Here, the conductivity type regions 20 and 30 may include a first conductivity type region 20 and a second conductivity type region 30 having different conductivity types, and the electrodes 42 and 44 may have a first conductivity type. It may include a first electrode 42 connected to the type region 20 and a second electrode 44 connected to the second conductive type region 30. It may further include an insulating film such as a first passivation film 22, an anti-reflection film 24, and a second passivation film 32.

The semiconductor substrate 12 may be composed of a crystalline semiconductor (eg, a single crystal or polycrystalline semiconductor, for example, single crystal or polycrystalline silicon) containing a single semiconductor material (eg, a group 4 element). Then, since it is based on the semiconductor substrate 12 with high crystallinity and few defects, the solar cell 10 can have excellent electrical characteristics.

The front and/or back side of the semiconductor substrate 12 may be textured to have irregularities. As an example, the unevenness may have a pyramid shape whose outer surface is composed of the (111) surface of the semiconductor substrate 12 and has an irregular size. Accordingly, if the surface roughness is relatively large, the reflectance of light can be lowered. However, the present invention is not limited to this.

In this embodiment, the semiconductor substrate 12 is doped with a first or second conductivity type dopant at a lower doping concentration than the first or second conductivity type regions 20 and 30, so that the semiconductor substrate 12 has a base region having a first or second conductivity type. Includes (12a). For example, in this embodiment, the base area 12a may have a second conductivity type.

As an example, the first conductive region 20 may form an emitter region that forms a pn junction with the base region 12a. The second conductive region 30 may form a back surface field that prevents recombination. Here, the first and second conductive regions 20 and 30 may be formed entirely on the front and back surfaces of the semiconductor substrate 12, respectively. As a result, the first and second conductive regions 20 and 30 can be formed with a sufficient area without separate patterning. However, the present invention is not limited to this. For example, the first or second conductive regions 20 and 30 may have various structures such as a homogeneous structure, a selective structure, and a local structure.

In this embodiment, the base region 12a and the conductive type regions 20 and 30 that make up the semiconductor substrate 12 are regions that have the crystal structure of the semiconductor substrate 12 and have different conductivity types, doping concentrations, etc. Illustrated. That is, it is exemplified that the conductive regions 20 and 30 are doped regions constituting a part of the semiconductor substrate 12. However, the present invention is not limited to this. Accordingly, at least one of the first conductive region 20 and the second conductive region 30 may be composed of an amorphous, microcrystalline, or polycrystalline semiconductor layer that is formed as a separate layer on the semiconductor substrate 12. In addition, various modifications are possible.

The first conductivity type dopant included in the first conductivity type region 20 may be an n-type or p-type dopant, and the second conductivity type dopant included in the base region 12a and the second conductivity type region 30 may be a p-type or n-type dopant. Group 3 elements such as boron (B), aluminum (Al), gallium (Ga), and indium (In) can be used as p-type dopants, and phosphorus (P) and arsenic (As) can be used as n-type dopants. Group 5 elements such as , bismuth (Bi), and antimony (Sb) can be used. The second conductivity type dopant of the base region 12a and the second conductivity type dopant of the second conductivity type region 30 may be the same material or may be different materials.

For example, the first conductivity type region 20 may have a p-type, and the base region 12a and the second conductivity-type region 30 may have an n-type. Then, holes, which move at a slower moving speed than electrons, can move to the front rather than the back of the semiconductor substrate 12, thereby improving conversion efficiency. However, the present invention is not limited to this, and the opposite case is also possible.

On the surface of the semiconductor substrate 12, insulating films such as first and second passivation films 22 and 32 that passivate defects in the conductive regions 20 and 30 and an anti-reflection film 24 that prevents reflection of light are formed. You can. This insulating film may be composed of an undoped insulating film that does not contain a separate dopant. The first and second passivation films 22 and 32 and the anti-reflection film 24 have portions corresponding to the first or second electrodes 42 and 44 (more precisely, portions where the first or second openings are formed). Except, it may be formed substantially entirely on the front or back side of the semiconductor substrate 12.

For example, the first or second passivation films 22 and 32 or the anti-reflection film 24 include a silicon nitride film, a hydrogen-containing silicon nitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, MgF ₂ , ZnS, TiO ₂ and It may have a single layer structure selected from the group consisting of CeO ₂ or a multilayer structure in which two or more layers are combined. For example, the first or second passivation films 22 and 32 may be composed of a silicon oxide film, and the anti-reflection film 24 may include silicon nitride. In addition, the material and layered structure of the insulating film can be modified in various ways.

The first electrode 42 is electrically connected to the first conductive region 20 through the first opening, and the second electrode 44 is electrically connected to the second conductive region 30 through the second opening. do. The first and second electrodes 42 and 44 are made of various materials (eg, metal materials) and may be formed to have various shapes.

In this embodiment, the first electrode 42 includes a plurality of first finger lines 42a extending in one direction, that is, a second direction (y-axis direction in the drawing) and positioned parallel to each other, and a first finger line It includes a first bus bar 42b formed in a direction intersecting (for example, orthogonal to) 42a, that is, in a first direction ((x-axis direction in the drawing) and electrically connected to the first finger line 42a. At this time, the wiring member 142 of the connection sheet 140 may be formed along the long axis of each solar cell 10. , the first bus bar 42b may be formed along the short axis of each solar cell 10.

There may be only one first bus bar electrode 42b, or as shown in FIG. 3, there may be a plurality of first bus bar electrodes 42b with a pitch greater than that of the first finger line 42a. At this time, the width of at least a portion of the first bus bar electrode 42b may be larger than the width of the first finger line 42a, but the present invention is not limited thereto. Accordingly, the width of the first bus bar electrode 42b may be equal to or smaller than the width of the first finger line 42a.

At this time, the number of first bus bars 42b is 4 to 33 (for example, 4 to 24, for example, 8 to 24, especially, 10 to 10) based on one side of the solar cell 10. There may be 24), and they may be located at even intervals from each other. In each solar cell 10, the first bus bar 42b may have a symmetrical shape when viewed in the direction in which the first finger line 42a extends. As a result, the moving distance of the carrier can be minimized while providing a sufficient number of wiring members 142 connected to the first bus bar 42b.

The first bus bar 42b includes a plurality of first pad portions 422 positioned in the second direction, and is relatively connected along the direction in which the wiring member connecting the solar cell 10 to the other solar cell 10 is connected. It may further include a first line portion 421 that has a narrow width and extends long. The first pad portion 422 can improve the adhesion of the connection sheet 140 to the wiring member 142 and reduce contact resistance, and the first line portion 421 can minimize light loss. Additionally, the first line portion 421 may provide a path for the carrier to bypass when some of the first finger lines 42a are disconnected.

The second electrode 44 includes a second finger line 44a and a second bus bar 44b corresponding to the first finger line 42a and the first bus bar 42b of the first electrode 42, respectively. can do. The second bus bar 44b includes a plurality of second pad parts 442 corresponding to the plurality of first pad parts 422 and a second line part 441 corresponding to the first line part 421. It can be provided. About the second finger line 44a and the second bus bar electrode 44b of the second electrode 44, about the first finger line 42a and the second bus bar electrode 42b of the first electrode 42 This can be applied as is. In addition, the contents related to the first passivation film 22 and the anti-reflection film 24, which are the first insulating films in the first electrode 42, are directly applied to the second passivation film 32, which is the second insulating film in the second electrode 44. You can. At this time, the width, pitch, thickness, etc. of the first finger line 42a, the first pad portion 422, and the first line portion 421 of the first electrode 42 are determined by the second finger of the second electrode 44. The width, pitch, thickness, etc. of the line 44a, the second pad portion 442, and the second line portion 441 may be the same or different from each other. The first bus bar 42b and the second bus bar 44b may be formed at the same location and may be formed in the same number. However, the present invention is not limited to this, and the first electrode 42 and the second electrode 44 may have different planar shapes, and various other modifications are possible.

As such, in this embodiment, the first and second electrodes 42 and 44 of the solar cell 10 have a certain pattern so that light can be incident on the front and back of the semiconductor substrate 12. It has a bi-facial structure. As a result, the amount of light used in the solar cell 10 can be increased, contributing to improving the efficiency of the solar cell 10.

However, the present invention is not limited to this, and it is possible for the second electrode 44 to have a structure formed entirely on the rear side of the semiconductor substrate 12. In addition, it is possible for the first and second conductive regions 20 and 30 and the first and second electrodes 42 and 44 to be located together on one side (eg, back) of the semiconductor substrate 12, It is also possible for at least one of the first and second conductive regions 20 and 30 to be formed over both surfaces of the semiconductor substrate 12 . That is, the solar cell 10 described above is merely presented as an example, and the present invention is not limited thereto.

Here, as described above, the solar cell 10 is manufactured by cutting the mother solar cell 100a along the cutting line CL. In this way, when the mother solar cell 100a is separated into a plurality of solar cells 10, an output loss (cell to module loss) occurs when the plurality of solar cells 10 are connected to make a solar cell panel 100. CTM loss) can be reduced. In other words, if the area of the solar cell 10 is reduced to reduce the current generated by the solar cell 10 itself, even if the number of solar cells 10 reflected as it is increases, the current reflected as a square value is reduced, thereby reducing the solar cell panel. The output loss of (100) can be reduced.

In this embodiment, after manufacturing the mother solar cell 100a using a conventional manufacturing method, it is cut to reduce the area of the solar cell 10. Accordingly, the existing equipment and the optimized design are used as is. After manufacturing the mother solar cell 100a, it can be cut. As a result, the equipment burden and process cost burden are minimized. On the other hand, if the size of the mother solar cell 100a is manufactured by reducing it, there is a burden of replacing the used equipment or changing the settings.

In general, it is manufactured from an ingot of approximately circular shape of the semiconductor substrate 12 of the mother solar cell 100a and has two axes orthogonal to each other such as circular, square, or similar shapes (for example, a first finger line) The lengths of the sides (an axis parallel to (42a) and an axis parallel to the first bus bar 42b) are the same or almost similar to each other. For example, in this embodiment, the semiconductor substrate 12 of the mother solar cell 100a may have an octagonal shape with slanted sides 12b at four corners in an approximately square shape. With this shape, the semiconductor substrate 12 with the largest possible area can be obtained from the same ingot. Accordingly, the mother solar cell 100a has a symmetrical shape, and the maximum horizontal axis, the maximum vertical axis, and the minimum horizontal axis and minimum vertical axis have the same length. In this embodiment, the solar cell 10 is formed by cutting the mother solar cell 100a along the cutting line CL, so that the solar cell 10 or the semiconductor substrate 12 has a long axis and a short axis.

The shapes of the above-described first and second electrodes 42 and 44, the structure of the solar cell 10, etc. may be modified in various ways. For example, the solar cell 10 may have various structures using a semiconductor substrate or semiconductor material, such as a back electrode solar cell, an amorphous solar cell, or a tandem solar cell. Alternatively, it may also have a structure such as a dye-sensitized solar cell or a compound semiconductor solar cell. Additionally, the position, direction, and shape of the cutting line CL can be modified in various ways.

The solar cell 10 described above is connected to a neighboring solar cell 10 by a connection sheet 140 including a wiring member 142 positioned on (for example, in contact with) the first electrode 42 or the second electrode 44. ), which will be described in more detail with reference to FIGS. 5 to 7 along with FIGS. 1 to 4.

FIG. 5 is a plan view schematically showing a plurality of solar cells 10 included in the solar cell panel 100 shown in FIG. 1 and connected by a connection sheet 140 including a plurality of wiring members 142. FIG. 6 is a perspective view schematically showing the connection sheet 140 provided with a plurality of wiring members 142 shown in FIG. 5. And FIG. 7 shows the first and second solar cells 10a and 10b in the overlapping portion OP of the first and second solar cells 10a and 10b included in the solar cell panel 100 shown in FIG. 1. And this is a partial cross-sectional view showing the connection sheet 140.

For simplicity of illustration and clear understanding, only the connection sheet 140 connecting the first and second solar cells 10a and 10b is shown in FIG. 5 . In cases where distinction is necessary for clear understanding, the connection sheet connecting the first and second solar cells 10a and 10b will be referred to as the connection sheet 140 in the following description, and the first or second solar cells 10a and 10b will be referred to as the connection sheet 140. The connecting sheets that connect 10b) to other solar cells 10c and 10d are called first and second connecting sheets 1401 and 1402. The description of the connection sheet 140 to be described later may also be applied to the first and second connection sheets 1401 and 1402, respectively.

As shown in FIGS. 1 to 7, the connection sheet 140 is provided with a plurality of wiring members 142 extending in a first direction and spaced apart from each other in a second direction, and physically fixing the plurality of wiring members 142. It may include an insulating portion 144 integrated with the plurality of wiring members 142 so as to do so. Accordingly, the plurality of wiring members 142 and the insulating portion 144 are integrated to form a connection sheet 140 composed of a single body. Accordingly, the first and second solar cells 10a and 10b can be connected using the integrated connection sheet 140 provided with a plurality of wiring members 142. Accordingly, the manufacturing process can be simplified compared to aligning and attaching the plurality of wiring members 142 connected to each solar cell 10 by individually moving them.

In this embodiment, the second solar cell 10b is positioned on the front surface of the first solar cell 10a so as to have an adjacent portion that contacts or overlaps the first solar cell 10a in the first direction. As an example, in FIG. 5, a portion of the rear surface of the second solar cell 10b is located on the front surface of the first solar cell 10a to form an overlap part OP, and this overlap part OP forms an adjacent part. Alternatively, the first and second solar cells 10a and 10b may contact each other in the first direction, and the portion where they contact each other may form an adjacent portion. This will be explained later with reference to FIG. 16.

In this embodiment, the wiring member 142 may be made of a wire having a smaller width than a ribbon having a relatively wide width (eg, exceeding 1 mm) that was previously used. For example, the width, diameter, or thickness (in particular, width or diameter) of the wiring member 142 may be 400 ㎛ or less (eg, 100 ㎛ to 400 ㎛, more specifically 100 ㎛ to 250 ㎛). Additionally, the width, diameter, or thickness (in particular, width or diameter) of the wiring member 142 may be larger than the width of the first and second finger lines 42a and 44a and smaller than their pitch. And the width, diameter, or thickness (in particular, width or diameter) of the wiring member 142 is larger than the first and second line portions 421 and 441 and equal to or greater than that of the first and second pad portions 422 and 442. It can be small. Here, the width, diameter, or thickness of the wiring member 142 may mean the largest width, diameter, or thickness among the width, diameter, or thickness of the wiring member 142. When the wiring member 142 has a width, diameter, or thickness (in particular, width or diameter) in the above-described range, the wiring member 142 can be smoothly attached to the solar cell 10 while keeping the resistance low and minimizing light loss. You can.

Additionally, a plurality of wiring members 142 may be provided on each connection sheet 140 based on one side of each solar cell 10 . For example, each connection sheet 140 is provided with 4 to 33 (for example, 4 to 24, for example, 8 to 24, in particular, 10 to 24) wiring members 142. It may be located at regular intervals in the second direction. In particular, the number of wiring members 142 (e.g., 6 to 24, more specifically, 10) is greater than the number of existing ribbons (e.g., 2 to 5) in each connection sheet 140. to 24) may be provided. Then, the travel distance of the carrier can be reduced by using a large number of wiring members 142 while minimizing light loss and material costs due to the small width of the wiring members 142 . Additionally, if each connection sheet 140 is provided with 24 or less wiring members 142, light loss can be effectively reduced. In this way, the efficiency of the solar cell 10 and the output of the solar cell panel 100 can be improved by reducing the light loss and the moving distance of the carrier, and the material cost due to the wiring material 142 can be reduced, thereby improving the solar cell panel 100 ) can improve productivity.

Here, the plurality of wiring members 142 in each solar cell 10 may have a symmetrical shape when viewed in the direction in which the first or second finger lines 42a and 44a extend. As a result, it is possible to minimize the moving distance of the carrier while providing a sufficient number of wiring members 142. Additionally, the wiring member 142 may be positioned to correspond one-to-one to the first and second bus bars 42b and 44b, respectively.

In this embodiment, in order to prevent the process of attaching the wiring member 142 to the solar cell 10 from becoming complicated when using a large number of wiring members 142 having a small width, the wiring member 142 is connected to the insulating portion 144. ) and is used in the form of an insulating sheet 140 composed of a single body. According to this, instead of performing a process of individually moving, aligning, and attaching a plurality of wiring members 142, one insulating sheet 140 can be moved, aligned, and attached. At this time, the insulating sheet 140 stably maintains the gap between the plurality of wiring members 142 and has structural stability, so that even if the position between neighboring solar cells 10 is fixed with a small fixing force, the solar cell 10 can be sufficiently maintained. ) can be connected to. Accordingly, there is no need to perform a separate tabbing process (for example, a soldering process) to attach the electrodes 42 and 44 and the wiring material 142 of the connection sheet 140, and the solar sealing material 130 is used in the lamination process. It can be stably connected to the battery 10. Accordingly, the manufacturing process can be further simplified since there is no need to perform a separate tabbing process.

However, the present invention is not limited to this, and a separate tabbing process may be performed to connect the electrodes 42 and 44 of the solar cell 10 and the wiring member 142 of the connection sheet 140 before the lamination process. Accordingly, the adhesion characteristics of the electrodes 42 and 44 and the wiring member 142 can be further improved.

For example, in this embodiment, the wiring material 142 may have a structure including a core layer 142a and a coating layer 142b formed on its surface. The coating layer 142b may be made of various materials that can improve adhesion characteristics with the electrodes 42 and 44. For example, even when a separate soldering process is not performed as described above, if the coating layer 142b includes a solder material, the coating layer 142b is exposed to the electrodes 42 and 44 and the wiring material ( 142) can play a role in improving the adhesive properties. For example, the core layer 142a may include Ni, Cu, Ag, Al, etc. as main materials (for example, a material containing 50 wt% or more, more specifically, a material containing 90 wt% or more). The coating layer 142b may include solder materials such as Pb, Sn, SnIn, SnBi, SnPb, SnPbAg, SnCuAg, and SnCu as a main material. However, the present invention is not limited to this, and the core layer 142a and the coating layer 142b may include various materials. For example, the coating layer 142b may be made of metal. Alternatively, the coating layer 142b may not be provided. Various other variations are possible.

This wiring material 142 or the core layer 142a included therein and accounting for most of the wiring material 142 may include a rounded portion. That is, the cross section of the wiring material 142 or the core layer 142a may include at least a portion of a circular shape, a portion of a circular shape, an oval shape, or a portion of an oval shape, a curved portion, or a rounded portion.

With this shape, the wiring material 142 is formed in a structure in which the coating layer 142b is positioned entirely on the surface of the core layer 142a, thereby omitting the process of separately applying a material to improve adhesive properties, etc., and forming the solar cell 10. The wiring material 142 can be attached by placing the wiring material 142 directly on top. Accordingly, the attachment process of the wiring member 142 can be simplified. In addition, reflection or diffuse reflection is induced in the rounded portion of the wiring material 142, so that the light reflected by the wiring material 142 can be re-entered into the solar cell 10 and reused. According to this, the amount of light incident on the solar cell 10 increases, thereby improving the efficiency of the solar cell 10 and the output of the solar cell panel 100. However, the present invention is not limited to this. Accordingly, the wire constituting the wiring member 142 may have a polygonal shape such as a triangle or a square, or may have various other shapes.

And the insulating part 144 includes a first insulating part 144a located on at least the front side of the first solar cell 10a, and a second insulating part 144b located on at least the back side of the second solar cell 10b. may include. At this time, the first insulating part 144a and the second insulating part 144b are located on one side and the other side of the plurality of wiring members 142, respectively, to form the first and second solar cells 10a and 10b and the plurality of wiring members. It does not interfere with the electrical connection of (142). That is, the first insulating portion 144a is located on the front side of the plurality of wiring members 142 and is connected to the first electrode 42 of the first solar cell 10a at a portion corresponding to the first solar cell 10a. The rear side of the plurality of wiring members 142 is exposed. And the second insulating portion 144b is located on the rear side of the plurality of wiring members 142 and is connected to the second electrode 44 of the second solar cell 10b at a portion corresponding to the second solar cell 10b. The front side of the plurality of wiring members 142 is exposed. The insulating sheet 140 having this structure can be easily manufactured by positioning the first insulating part 144a and the second insulating part 144b on opposite sides of one side and the other side of the plurality of wiring members 142. there is.

In this embodiment, the first or second insulating portions 144a and 144b may have various thicknesses. For example, the thickness of the first or second insulating portions 144a and 144b may be equal to, larger or smaller than the width or diameter of the wiring member 142. And it may have a thickness equal to or smaller than that of the first or second sealing materials 131 and 132. Alternatively, the thickness of the first or second insulating portions 144a and 144b may be 10 um to 500 um (for example, 40 um and 400 um). In the drawing, the first or second insulating portions 144a and 144b are shown as having a flat shape in the portion exposed to the outside, but in reality, the first or second insulating portions 144a and 144b are the portion where the wiring member 142 is located. It may be formed with a curve along the surface of the wiring member 142. Various other variations are possible.

Here, the plurality of wiring members 142 is located on the rear surface of the first insulating part 144a in a portion corresponding to the first solar cell 10a and has a first exposed portion EP1 exposed to the outside from the rear side. A device having a first extension portion 1422 and a second exposed portion EP located on the front surface of the second insulating portion 144b in a portion corresponding to the second solar cell 10b and exposed to the outside from the front side. 2 May include an extension portion 1423. That is, on the rear side facing the first solar cell 10a, the first exposed portion EP1 of the first extension portion 1422 of the plurality of wiring members 142 extends along the first direction and is spaced apart in the second direction. It can be. And, on the front side facing the second solar cell 10b, the second exposed portion EP2 of the second extension portion 1423 of the plurality of wiring members 142 extends along the first direction and is spaced apart in the second direction. You can.

At this time, the wiring member 142 provided on one connection sheet 140 is connected to the first electrode 42 located on the front side of the first solar cell 10a and the second solar cell adjacent to one side (upper side in FIG. 5). The second electrode 44 located on the back of the battery 10b is connected. More specifically, the first exposed portion EP1 of the first extension portion 1422 is connected (for example, contacts) to the first electrode 42 of the first solar cell 10a, and the second solar cell 10b ) The second exposed portion EP2 of the second extension portion 1423 is connected (for example, in contact) with the second electrode 44 of ). Similarly, the wiring member 142 provided on the first connection sheet 141 is a first electrode located on the front of the third solar cell 10c located on the other side (lower side of FIG. 5) of the first solar cell 10a. (42) and the second electrode 44 located on the back of the first solar cell 10a are connected. In addition, the wiring member 142 provided on the second connection sheet 1402 is connected to the first electrode 42 located in the front of the second solar cell 10b and one side (upper side in FIG. 5) of the second solar cell 10b. The second electrode 44 located on the back of another solar cell 10d is connected. Accordingly, the plurality of solar cells 10 can be connected to each other to form a row by the connection sheets 140, 1401, and 1402 provided with the wiring member 142. Hereinafter, the description of the wiring member 142 and the connection sheet 140 provided therewith may be applied to all the wiring members 142 and the connection sheet 140 provided therefor that connect two adjacent solar cells 10. there is.

At this time, in this embodiment, adjacent portions where the first insulating portion 144a and the second insulating portion 144b contact or overlap each other are provided corresponding to adjacent portions of the first and second solar cells 10a and 10b. It can be. Here, whether the first and second insulating portions 144a and 144b are in contact with each other or overlap can be determined based on a planar view. For example, an overlap portion (OP1) where the first insulating portion (144a) and the second insulating portion (144b) overlap each other is provided corresponding to the overlapping portion (OP) of the first and second solar cells (10a, 10b). It can be. At this time, an overlap portion OP1 in which the first and second insulating portions 144a and 144b are located together may be located between the first and second solar cells 10a and 10b in the overlap portion OP. For example, the overlapping portion OP1 may have a length and width that are smaller than the overlapping portion OP and may be positioned so as not to be exposed to the outside of the overlapping portion OP. This reduces material costs and allows light to enter with higher transmittance.

Then, the overlapping part OP1 of the first and second insulating parts 144a and 144b fills the space between the first and second solar cells 10a and 10b overlapped in the overlapping part OP, thereby forming the first and second solar cells. The fixation stability of the batteries 10a and 10b can be improved. As a result, stress applied to the wiring member 142 or the first and second solar cells 10a and 10b positioned between them can be distributed by the insulating portion 144. In this way, the stress applied to the wiring member 142 or the first and second solar cells 10a and 10b positioned between them can be reduced, thereby further reducing the width, diameter, and thickness of the wiring member 142. On the other hand, if the width, diameter, or thickness of the wiring member 142 passing through the overlap portion (OP), or the thickness of the connection sheet 140 is large, the wiring member 142 located in the overlap portion OP may cause damage to the solar cell 10. Problems such as damage or cracking of the solar cell 10 may occur due to pressure being applied.

At this time, in the overlapping portion OP, a plurality of wiring members 142 are spaced apart from each other in the second direction between the first and second insulating portions 144a and 144b and are spaced apart from the first and second solar cells 10a and 10b. can be located. The plurality of wiring members 142 are connected to the first electrode 42 in light-receiving parts other than the overlapping part OP of the first solar cell 10a, and are connected to the first electrode 42 in light-receiving parts other than the overlapping part OP of the second solar cell 10b. Since it is connected to the second electrode 44 at the overlapping portion OP, it does not need to be connected to the first or second solar cells 10a and 10b or the first or second electrodes 42 and 44 formed thereon. Because it does. For example, in this embodiment, the first electrode 42 of the first solar cell 10a and the second electrode 44 of the second solar cell 10b are not formed in the overlapping portion OP, thereby reducing material costs. can do. However, the present invention is not limited to this.

In Figure 7, the boundary between the first and second insulating parts 144a and 144b in the overlapping portion OP is indicated by a dashed line, but after the lamination process, the boundary between the first and second insulating parts 144a and 144b actually exists. You may not. In this case, the insulating portion 144 is located between the first and second solar cells 10a and 10b in the overlapping portion OP, and the plurality of wiring members 142 are connected in the second direction within the insulating portion 144. They may be positioned spaced apart from each other and spaced apart from the first and second solar cells 10a and 10b. However, the present invention is not limited to this. That is, the first and/or second insulating portions 144a and 144b may not be located in the overlapping portion OP. This will be described in detail later with reference to FIGS. 10 to 13. Additionally, the first and/or second electrodes 42 and 44 may or may not be formed in the overlapping portion OP.

In FIG. 6 , both ends of the plurality of wiring members 142 are positioned to coincide with the edges of the first and second insulating portions 144a and 144b, respectively. That is, one end of the plurality of wiring members 142 is positioned to coincide with one edge of the first insulating portion 144a, and the other end of the plurality of wiring members 142 is positioned to coincide with the other edge of the second insulating portion 144b. can be located Then, the connection sheet 140 can be manufactured by aligning the plurality of wiring members 142, arranging the first and second insulating parts 144a and 144b alternately, and then cutting the plurality of wiring members 142. However, the present invention is not limited to this. Accordingly, one end of the plurality of wiring members 142 may be located inside one edge of the first insulating portion 144a or may extend outward past one edge, and/or the other end of the plurality of wiring members 142 may be located inside the first insulating portion 144a. It may be located inside the other edge of the second insulating portion 144b or may extend outward past the other edge. Various other variations are possible.

5 and 7 , the shape of the coating layer 142b changes in the wiring member 142 attached or connected to the solar cell 10 by the lamination process or the tabbing process, and the shape of the coating layer 142b changes between the first and second solar cells 10. In the wiring member 142 spaced apart from these, the coating layer 142b maintains its circular shape. More specifically, during the lamination process or the tabbing process, each coating layer 142b flows down as a whole toward the first or second electrodes 42 and 44 (more specifically, the first and second pad portions 422 and 442), respectively. In the portion adjacent to the first and second pad portions 422 and 442 or in the portion located between the first and second pad portions 422 and 442 and the core layer 142a, the width of the coating layer 142b is equal to the width of the first and second pad portions 422 and 442. 2 It may have a shape that gradually increases toward the pad portions 422 and 442. For example, the portion of the coating layer 142b adjacent to the first and second pad portions 422 and 442 may have a width equal to or greater than the width or diameter of the core layer 142a. At this time, the width of the coating layer 142b may be equal to or smaller than the width of the first and second pad portions 422 and 442. And, in the wiring member 142 spaced apart from the first and second solar cells 10, the coating layer 142b has a uniform thickness and can maintain a circular shape. And the portion of the wiring member 142 located in a portion (for example, the outside of the solar cell 10) where heat is not applied or relatively little heat is applied during the lamination process or tabbing process is shown in the enlarged circle on the left of FIG. 1. As described above, the coating layer 142b has a uniform thickness on the entire surface of the core layer 142a and can maintain a circular shape. However, the present invention is not limited to this. Accordingly, in the wiring member 142 attached or connected to the solar cell 10, the coating layer 142b has a uniform thickness on the entire surface of the core layer 142a and can maintain a circular shape.

According to this embodiment, light loss due to diffuse reflection, etc. can be minimized by using wire-shaped wiring members 142, and the carrier movement path can be reduced by increasing the number of wiring members 142 and reducing the pitch of the wiring members 142. . Additionally, material costs can be greatly reduced by reducing the width or diameter of the wiring member 142. As a result, the efficiency of the solar cell 10 and the output of the solar cell panel 100 can be improved. At this time, the wiring material 142 can be embedded in the connection sheet 140 to improve structural stability and simplify the manufacturing process.

As described above, the solar cell 10 having a long axis and a short axis according to this embodiment can be extended in the first direction (x-axis direction in the drawing) by the connection sheet 140 provided with the wiring member 142. More specifically, a partial portion of one side (upper side in FIG. 5) from the front of the first solar cell 10a in the minor axis direction and a partial portion of the other side (lower side of FIG. 5) from the rear of the second solar cell 10b They overlap to form an overlapping part (OP), so that the overlapping part (OP) can extend long along the long axis direction of the first and second solar cells 10a and 10b. At this time, the plurality of wiring members 142 embedded in the connection sheet 140 are positioned so as to pass through the overlap portion OP between the front of the first solar cell 10a and the rear of the second solar cell 10b located above. can do. Thereby, the first and second solar cells 10a and 10b are connected. Here, the plurality of wiring members 142 are oriented in a first direction (x-axis direction in the drawing, minor axis direction, direction intersecting the first and second finger lines 42a, 44a, first and second bus bars 42b, 44b). ) may extend along the extension direction of the solar cell string (S), the longitudinal direction of the solar cell string (S). On one side of each solar cell 10, a plurality of wiring members 142 may be positioned to be spaced apart from each other in a second direction crossing the first direction.

At this time, the plurality of wiring members 142 in the connection sheet 140 extend in the minor axis direction to pass through the overlap portion OP, passing through the plurality of first and second finger lines 42a and 44a extending long in the major axis direction. It can be located as follows. Here, the plurality of wiring members 142 each have a middle portion ( 1421) and a first extension portion 1422 extending from the middle portion 1421 to a light receiving portion other than the adjacent portion (eg, overlapping portion OP) on the front surface of the first solar cell 1421. It may further include a second extension portion 1423 extending from the other side of the middle portion 1422 to a portion other than the adjacent portion (e.g., overlapping portion OP) at the back of the second solar cell 10b. . Accordingly, each wiring member 142 is connected to an adjacent part (eg, an overlapping part (OP)) from one side (the lower side of FIG. 5) of the first solar cell 10a opposite to the adjacent part (eg, an overlapping part (OP)) in the first direction. (OP)) and may be positioned to extend long to the other side (upper side of FIG. 5) of the second solar cell 10b.

At this time, as described above, a plurality of first finger lines 42a extending long in the long axis direction may be provided on the front surfaces of the first and second solar cells 10a and 10b, and the first and second solar cells ( A plurality of second finger lines 44a extending long in the long axis direction may be provided on the rear surfaces of 10a and 10b). Then, as shown in the lower enlarged view of FIG. 5, the first extension portion 1422 is formed in the minor axis direction or the first direction and is positioned on the front surface of the first solar cell 10a. ) can be positioned to pass through. At this time, the first extension portion 1422 extends parallel to the first bus bar 42b connecting the plurality of first finger lines 42a to form the first bus bar 42b (i.e., the first pad portion 422 ) and the first line portion 421). And, as shown in the upper enlarged view of FIG. 5, a plurality of second finger lines 44a in which the second extension portion 1423 is formed in the minor axis direction or the first direction and is located on the rear side of the second solar cell 10b. It can be formed to pass through . At this time, the second extension portion 1423 extends parallel to the second bus bar 44b connected to the plurality of second finger lines 44a to form the second bus bar 44b (i.e., the first pad portion 442). and the first line portion 441). For reference, the lower enlarged view of FIG. 5 is a front plan view of the first solar cell 10a, and the upper enlarged view of FIG. 5 is a rear plan view of the second solar cell 10b, and the wiring member 142 and the first and Only two electrodes 42 and 44 are shown.

In this way, the first and second finger lines 42a and 44a are formed in the long axis direction in the first and second solar cells 10a and 10b, and the wiring material 142 is positioned in the short axis direction to form the first and second solar cells 10a and 10b. And the second finger lines 42a and 44a can stably collect carriers. In addition, since a large number of wiring members 142 can be provided, the carrier movement path is short and carrier collection efficiency can be effectively improved. In addition, by positioning the wiring member 142 in the minor axis direction, the length of the wiring member 142 connecting the first and second solar cells 10a and 10b can be reduced, thereby reducing the thermal stress that may occur when the wiring member 142 is long. problems can be prevented.

In particular, the plurality of wiring members 142 located between the front surface of the first solar cell 10a and the rear surface of the second solar cell 10b extend in a direction intersecting the plurality of first finger lines 42a. By providing an extension portion 1422, current collection efficiency at the front side can be improved. When the first conductive region 20, which functions as an emitter region, is provided on the front side, current collection efficiency can be effectively improved. In addition, by providing a first extension part 1422 and a second extension part 1423, the current collection efficiency on both sides can be improved.

At this time, the wiring member 142 may be directly connected to at least one of the finger lines 42a and 44a of the first and second electrodes 42 and 44 and the bus bars 42b and 44b. More specifically, the wiring member 142 (in particular, the first exposed portion EP1) is connected to at least one of the plurality of first finger lines 42a and the first bus bar 42b of the first solar cell 10a. may be connected to the wiring member 142 (in particular, the second exposed portion EP2) to at least one of the plurality of second finger lines 44a and the second bus bar 44b of the second solar cell 10b. there is. As a result, there is no need to form a separate pad for connection to the wiring member 142, so the structure and manufacturing process can be simplified. Additionally, light loss due to separate pads, etc. can be minimized. In addition, the wiring member 142 serves as an interconnector connecting the first and second solar cells 10a and 10b, as well as a current collection electrode that collects current or a bypass electrode that provides a bypass path for carriers. It can be done.

In this embodiment, the wiring material 142 is attached to and fixed to the pad portions 422 and 442 and/or the line portions 421 and 441. However, the present invention is not limited to this. In addition, in the case where the first and/or second bus bars 42b and 44b are not provided as in the embodiment to be described later with reference to FIG. 15, the wiring material 142 within the overlap portion OP is connected to the first and/or second bus bars 42b and 44b. /Or it may be electrically and/or physically connected (for example, directly connected) to the finger lines 42a and 44a of the second electrodes 42 and 44.

In this embodiment, the first and second solar cells 10a and 10b are connected through an overlapping portion OP, so the number of solar cells 10 located in the solar cell panel 100 and the number of solar cells 10 are The area of the area where it is located can be maximized. As a result, the output and efficiency per unit area of the solar cell panel 100 can be improved. At this time, since the first and second solar cells 10a and 10b are connected using a plurality of wiring members 142 extending in a direction intersecting the longitudinal direction of the overlap portion OP, the overlap portion OP is conventionally connected. In the structure provided, the conductive adhesive layer located along the longitudinal direction of the overlap portion (OP) is not provided. The conductive adhesive layer used conventionally may be made of a conductive adhesive material (electrical conductive adhesive, ECA). In order to form such a conductive adhesive layer, a complex process must be performed in which a viscous liquid or paste-like conductive adhesive material containing a conductive material, binder, solvent, etc. is applied using a nozzle and then cured at a certain temperature. In this embodiment, the process of forming a conductive adhesive layer can be omitted, thereby simplifying the manufacturing process, improving the stability of the manufacturing process, and reducing material costs. However, the present invention is not limited to this and a conductive adhesive layer may also be used.

For example, in this embodiment, the width, diameter, or thickness of the wiring member 142 (in particular, the width or diameter), or the connection sheet 140 is greater than the width of the overlap portion OP in the short axis direction of the solar cell 10. The thickness may be small. And the distance, or connection, between the first solar cell 10a and the second solar cell 10b located in the overlapped portion OP in the thickness direction is greater than the width of the overlapped portion OP in the short axis direction of the solar cell 10. The thickness of the sheet 140 may be smaller. Alternatively, the width of the overlap portion OP in the minor axis direction may be 2 mm or less (for example, 1 mm or less). Then, the structural stability of the connection structure of the first and second solar cells 10a and 10b may be excellent. In particular, in this embodiment, since the solar cell 10 having a major axis and a minor axis is used, the width, diameter, or thickness (in particular, the width or diameter) of the wiring member 142 can be further reduced. If the mother solar cell 100a is used as is, the resistance is large, so the width of the wiring member 142 must be secured at a certain level or more. However, if the solar cell 10 cut to have a minor axis and a major axis as in the present embodiment is used, the area is reduced. Since it is small and has low resistance, the width, diameter, or thickness (in particular, width or diameter) of the wiring member 142 can be further reduced. For example, the width, diameter, or thickness of the wiring member 142 may be 250 μm or less (eg, 100 μm to 200 μm). According to this, structural stability can be further improved by further reducing the width, diameter, or thickness of the wiring member 142.

In this embodiment, at least a portion of the rear surface of the second solar cell 10b located above the first solar cell 10a is located ahead of the front surface of the first solar cell 10a. Here, located in the front may mean located in the front when viewed in the thickness direction (z-axis direction in the drawing) of the solar panel 100, and the position of the first and second solar cells 10a and 10b It may mean that it is located at the front when viewed in the thickness direction (i.e., a direction perpendicular to the first and second solar cells 10a and 10b and inclined to all the x-axis, y-axis, and z-axis of the drawing). . For example, in a portion where the first and second solar cells 10a and 10b are adjacent to each other (e.g., an adjacent portion such as an overlapping portion (OP)), the rear surface of the second solar cell 10b is adjacent to the first solar cell. It may be located ahead of the front of (10a). At this time, when viewed from the thickness direction of the first and second solar cells 10a and 10b, the second solar cell 10b is at least in the overlapping portion OP or adjacent portions of the first and second solar cells 10a and 10b. The back side of may be located ahead of the front side of the first solar cell 10a by the width, diameter, or thickness of the wiring member 142 or the thickness of the connection sheet 140. For example, when viewed in the thickness direction of the first and second solar cells 10a and 10b, the rear of the second solar cell 10b may be positioned entirely ahead of the front of the first solar cell 10a. And when viewed in the thickness direction of the first and second solar cells 10a and 10b, at least a portion of the second exposed portion EP2 connected to the second solar cell 10b is connected to the first solar cell 10a. It may be located ahead of the exposed portion (EP1).

Here, in the thickness direction of the first or second solar cells 10a and 10b, the position difference between the connection sheet 140 or the plurality of wiring members 142 is greater than the thickness of the first or second solar cells 10a and 10b. It can be small. For example, the maximum difference in the position of the front surface of the connection sheet 140 in the thickness direction of the first or second solar cell 10a, 10b, or the maximum difference in the position of the rear surface of the connection sheet 140 is the difference between the first or second solar cells 10a and 10b. It may be smaller than the thickness of the second solar cells 10a and 10b. For example, the maximum difference in the position of the front side of the connection sheet 140 in the thickness direction of the first or second solar cell 10a, 10b, or the maximum difference in the position of the rear side of the connection sheet 140 is the first or second solar cell 10a, 10b. 2 It may be 50% or less (for example, 30% or less) of the thickness of the solar cells 10a and 10b. Alternatively, the position difference between the middle part 1421 and the first extension part 1422 in the plurality of wiring members 142, the middle part 1421 and the second extension part 1423, and the first extension part 1422 and the first extension part 1422 The position difference between the two extension parts 1423 may be smaller than the thickness of the first or second solar cells 10a and 10b. For example, in the thickness direction of the first or second solar cell (10a, 10b), the position difference between the middle part 1421 and the first extension part 1422, the middle part 1421 and the second extension part 1423 The position difference between the first and second extension parts 1422 and 1423 is 50% or less (for example, 30% or less) of the thickness of the first or second solar cells 10a and 10b. It can be.

Alternatively, when viewed in a cross section (xz plane in the drawing) perpendicular to the second direction (y-axis direction in the drawing), from one side (left side of FIG. 2) of the first solar cell 10a to the other side of the second solar cell 10b The connection sheet 140 or the wiring member 142 extending to (right side of FIG. 2) may not have a portion that is bent or folded at an acute angle. For example, the first and second solar cells 10a and 10b are positioned substantially parallel to each other, and the connection sheet 140 or wiring member 142 is positioned between the first and second solar cells 10a and 10b. may be positioned substantially parallel to them. Accordingly, even if the connection sheet 140 or the wiring member 142 is slightly curved, the smaller angle among the curved portions may be 150 to 180 degrees (for example, 160 to 180 degrees). In this way, since the connection sheet 140 or the wiring member 142 does not have any bent, folded, or greatly curved parts, the wiring member ( 142) or problems such as damage or deterioration of characteristics of the solar cell 10 do not occur.

Conventionally, in a state where the front surfaces of the first and second solar cells are located substantially on the same plane and the rear surfaces of the first and second solar cells are located substantially on the same plane, the wiring material or connection sheet is connected to the front surface of the first solar cell. It must extend to the back of the second solar cell. Accordingly, since the wiring material or connection sheet must extend from the front to the back located on completely different planes, the wiring material or connection sheet must be provided with a greatly curved portion (for example, a portion bent at an angle of less than 150 degrees). do. Accordingly, if the width, diameter, or thickness of the wiring material is small, problems such as damage to the wiring material or deterioration of characteristics may occur. In addition, the wiring material or connection sheet must extend from the front to the back between the side of the first solar cell and the side of the second solar cell, so that the distance between the first solar cell and the second solar cell (distance between the sides) is sufficient. It has to be. If the distance between the first solar cell and the second solar cell is not sufficient, an unwanted shunt, etc. may occur due to the wiring material. Accordingly, there was a limit to reducing the distance between a plurality of solar cells, so the number of solar cells included in the solar cell panel was small and the area where the solar cells were not located was large. Accordingly, there were limits to improving the output and efficiency per unit area of solar panels. In particular, when using a connection sheet containing wiring material, flexibility may be relatively low due to the insulating portion, and problems due to shunts, etc. may become more serious, and the distance between solar cells may be increased. It was more difficult to reduce.

The process of connecting the first and second solar cells 10a and 10b according to the above-described embodiment is as follows. A first connection sheet 1421 including a plurality of first wiring members 142 is placed on a workbench, and a second finger line 44a of the second electrode 44 of the first solar cell 10a is formed on the first connection sheet 1421. 1 Position the first solar cell 10a so that it crosses and connects to the wiring member 142. And the connection sheet 140 including a plurality of wiring members 142 is positioned on the first solar cell 10a so as to intersect the first finger line 42a of the first electrode 42 of the first solar cell 10a. Then, the second solar cell 10b is placed on the solar cell 10a and the connection sheet 140 to form an overlapping portion OP with the first solar cell 10a. At this time, the plurality of wiring members 142 included in the connection sheet 140 and the second finger line 44a of the second electrode 44 of the second solar cell 10b may be crossed and connected. The connection structure of the adjacent first and second solar cells 10a and 10b as described above is continuously repeated in the two adjacent solar cells 10, so that the plurality of solar cells 10 are aligned in the first direction (in the drawing). They may be connected in series along the x-axis direction) or along the short axis direction of the solar cells 10 to form a solar cell string (S) consisting of one row. Accordingly, in the manufacturing apparatus of the solar cell panel 100, the distance between neighboring solar cells 10 is adjusted to zero (0) or negative (-) so that the neighboring solar cells 10 have adjacent parts. A solar cell string (S) can be formed. Accordingly, existing manufacturing equipment can be used by changing the settings, thereby reducing the equipment burden. Such a solar cell string (S) can be formed by various methods or devices.

In the lamination process of stacking the solar cell string (S), the sealing material 130, and the first and second cover members 110 and 120 and applying heat and pressure, the wiring material 142 of the connection sheet 140 is used to form one solar cell. It may be connected to the first electrode 42 of the first solar cell 10a (e.g., the first solar cell 10a) and the second electrode 44 of the adjacent solar cell (e.g., the second solar cell 10b). . According to this, the manufacturing process can be simplified by omitting a separate soldering process. However, the present invention is not limited to this, and the soldering process may be separately performed before the lamination process.

In the above-described embodiment, one mother solar cell 100a is cut with one cutting line CL to manufacture two solar cells 10, and these solar cells 10 are connected to form a solar cell panel 100. Formation was exemplified. Alternatively, as shown in FIG. 8, three or more solar cells 10 may be manufactured from one mother solar cell 100a by cutting one mother solar cell 100a with two or more cutting lines CL. there is. At this time, the plurality of cutting lines CL may have a long shape extending parallel to each other and may be formed to be spaced apart at regular intervals in a direction intersecting the longitudinal direction. In FIG. 8, it is illustrated that three solar cells 10 are manufactured from one mother solar cell 100a with two cutting lines CL. However, one mother solar cell 10 is manufactured with three or more cutting lines CL. Four or more solar cells 10 may be manufactured from the solar cell 100a.

Here, in each solar cell 10 having a minor axis and a major axis, the ratio of the length of the major axis to the minor axis may be 1.5 to 6.5 (for example, 1.5 to 4.5). This range is 2 to 6 (for example, 2 to 4) solar cells along 1 or 5 (for example, 1 or 3) cutting lines CL from the mother solar cell 100a. This range corresponds to the case where the overlapping part (OP) and process errors are taken into consideration when manufacturing the battery 10. The effects described above can be achieved by manufacturing and using a plurality of solar cells 10 from the mother solar cell 100a. At this time, when the number of solar cells 10 manufactured from the mother solar cell 100a is 4 or less (for example, 6 or less), the dead area due to the overlap portion OP is minimized. can do. Additionally, the manufacturing process can be simplified by reducing the number of connection processes using the connection sheet 140. However, the present invention is not limited to this.

In addition, in the above-described embodiment, a plurality of solar cells 10 are arranged and connected so as to maintain the shape of the mother solar cell 100a. That is, the inclined portion 12b is arranged according to the shape of the mother solar cell 100a, so that the long sides where the inclined portion 12b is located form an overlapping portion (OP), and the long side where the inclined portion 12b is not located is They can form an overlap (OP) with each other. According to this, the two solar cells 10 constituting the overlapping portion OP have symmetrical shapes, thereby improving electrical and structural connection characteristics. However, the present invention is not limited to this. Therefore, as a modified example, as shown in FIG. 9, the long side where the inclined portion 12b is located and the long side where the inclined portion 12b is not located may be arranged to form an overlapping portion OP. Various other variations are possible. For simplicity of illustration, FIG. 9 mainly shows the inclined portion 12b and does not show the wiring member 142.

According to this embodiment, the number of solar cells 10 included in the solar cell panel 100 and the area where the solar cells 10 are located can be maximized by applying a structure that minimizes the distance between solar cells 10. You can. As a result, the output of the solar cell panel 100 can be improved and efficiency per unit area can be improved. For example, by reducing the distance between solar cells 10, efficiency per unit area can be improved by more than 6% (for example, 6 to 10%). At this time, the manufacturing process can be simplified, the stability of the manufacturing process can be improved, and the cost can be reduced by not using a conductive adhesive layer. In addition, the manufacturing process is further simplified by using a connection sheet 140 with a plurality of wiring members 142 embedded in a connection structure that applies an adjacent portion (for example, an overlapping portion (OP)) and the wiring member 142. The stress applied to the solar cell 10 can be reduced. As a result, the stability of the connection structure of the solar cell 10 can be improved, thereby improving the productivity and reliability of the solar cell panel 100. In particular, since the insulating portion 144 of the connection sheet 140 also serves to withstand the load from the adjacent portion (for example, the overlap portion (OP)), the stress applied to the solar cell 10 and the wiring material 142 By minimizing , the width of the wiring member 142 can be greatly reduced. By reducing the width of the wiring member 142, the thickness of the semiconductor substrate 12 can also be reduced, thereby further reducing material costs. At this time, the solar cell 10 can use a connection sheet 144 that has a long axis and a short axis and is provided with a wiring member 142 having a small width, diameter, or thickness (in particular, width or diameter), thereby providing structural and electrical connection. Stability can be improved.

Hereinafter, a solar cell panel according to another embodiment of the present invention will be described in detail. Detailed description of parts that are the same or extremely similar to the above description will be omitted, and only different parts will be described in detail. Also, combining the above-described embodiments or modified examples thereof with the following embodiments or modified examples thereof also falls within the scope of the present invention.

FIG. 10 is a partial cross-sectional view showing various examples of a connection structure using a connection sheet at an overlapping portion of the first and second solar cells in a solar cell panel according to another embodiment of the present invention.

Referring to FIG. 10 , in this embodiment, the wiring member 142 of the connection sheet 140 may be attached and fixed to at least one of the first and second electrodes 42 and 44 in the overlapping portion OP. For example, the wiring member 142 of the connection sheet 140 may be attached and fixed to the pad portions 422 and 442 or may be attached and fixed to the line portions 421 and 441.

Accordingly, in the overlapping portion OP, the wiring member 142 is attached to and fixed to at least a portion of the first bus bar 42b of the first solar cell 10a or the second bus bar 42b of the second solar cell 10b. It may be attached and fixed to at least a portion of (44b). That is, in the overlapping part OP, the wiring material 142 is attached and fixed to the first pad part 422 and/or the first line part 421 of the first solar cell 10a located in the overlapping part OP. , may be attached and fixed to at least a portion of the second pad portion 442 and/or the second line portion 441 of the second solar cell 10b located within the overlap portion OP. As a result, the wiring material 142 and the first or second electrodes 42 and 44 are connected within the overlap portion OP, thereby improving electrical connection characteristics, structural stability, etc.

For example, as shown in (a) of FIG. 10, the first pad portion 422 of the first solar cell 10a and the second pad portion of the second solar cell 10b are attached to the overlapping portion OP. 442 are positioned respectively, so that the first and second exposed portions (reference numerals EP1 and EP2 in FIG. 6, hereinafter the same) of the wiring material 142 (i.e., the middle portion 1421) in the overlapping portion OP are respectively It may be respectively attached and fixed (for example, directly connected) to the first pad part 422 of the first solar cell 10a and the second pad part 442 of the second solar cell 10b. Alternatively, as shown in (b) of FIG. 10, the first line portion 421 of the first solar cell 10a and the second line portion 441 of the second solar cell 10b are attached to the overlapping portion OP. ) are positioned respectively, so that the first and second exposed portions EP1 and EP2 of the wiring member 142 (i.e., the middle portion 1421) in the overlapping portion OP are the first and second exposed portions EP1 and EP2 of the first solar cell 10a, respectively. It may be attached and fixed (for example, directly connected) to the line portion 421 and the second line portion 441 of the second solar cell 10b, respectively. 10 (a) and (b) illustrate that the wiring material 142 is attached and fixed to the pad parts 422 and 442, respectively, or to the line parts 421 and 441, respectively, in the overlap part OP. did. However, the present invention is not limited to this, and the wiring material 142 (i.e., the middle portion 1421) in the overlap portion OP is connected to the first pad portion 422 and the first line portion ( 421), and is attached and fixed (for example, directly connected) to at least one of the second pad portion 442 and the second line portion 441 of the second solar cell 10b ( For example, it may be directly connected.

And as shown in (c) of FIG. 10, the first bus bar 42b or the first electrode 42 of the first solar cell 10a is located in the overlap portion OP, but the second solar cell 10b ) of the second bus bar 44b or the second electrode 44 is not located, and the first and second exposed portions EP1 of the wiring member 142 (i.e., the middle portion 1421) in the overlap portion OP. , EP2) are attached and fixed (for example, directly connected) to the first bus bar 42b or the first electrode 42 of the first solar cell 10a, respectively, and are connected to the second bus of the second solar cell 10b. It may not be attached or fixed to the bar 44b or the second electrode 44. Alternatively, as shown in (d) of FIG. 10, the second bus bar 44b or the second electrode 44 of the second solar cell 10b is located in the overlapping portion OP, but the first solar cell ( The first bus bar 42b or the first electrode 42 of 10a) is not located, and the first and second exposed portions of the wiring member 142 (i.e., the middle portion 1421) in the overlap portion OP ( EP1 and EP2) are respectively attached and fixed (for example, directly connected) to the second bus bar 44b or the second electrode 44 of the second solar cell 10b and the first solar cell 10a. It may not be attached or fixed to the bus bar 42b or the first electrode 42.

However, the present invention is not limited to this. For example, in the case where the first and/or second bus bars 42b and 44b are not provided as in the embodiment to be described later with reference to FIG. 15, the wiring member 142 is connected to the first bus bar 142 within the overlapping portion OP. And/or may be electrically and/or physically connected (for example, directly connected) to the finger lines 42a and 44a of the second electrodes 42 and 44. And, even if the electrodes 42 and 44 are located within the overlapping part OP, the wiring material 142 is connected to the first electrode 42 of the first solar cell 10a and the second solar cell 10b. It may be positioned in a state where it is not attached or fixed between the second electrodes 44.

Additionally, in this embodiment, the first and second insulating portions 144a and 144b are not formed in the portion corresponding to the overlapping portion OP, so that the first and second insulating portions 144a and 144b are formed with the overlapping portion OP interposed therebetween. 144b) is an example of being spaced apart. However, the present invention is not limited to this. As a modified example, as shown in (a) of FIG. 11, the first and second insulating portions 144a and 144b are positioned spaced apart from each other within the overlapping portion OP and have a plurality of insulating portions within the overlapping portion OP. The wiring member 142 may be connected to the first electrode 42 of the first solar cell 10a and the second electrode 44 of the second solar cell 10b. As another modified example, as shown in (b) of FIG. 11, the first insulating part 144a is extended to the inside of the overlapping part OP, and the second insulating part 144b is located outside the overlapping part OP. Located in the overlapping portion OP, a plurality of wiring members 142 are connected to the first electrode 42 of the first solar cell 10a and to the second electrode 44 of the second solar cell 10b. It may not be connected. According to this, current collection efficiency can be improved by securing a relatively large area of the wiring material 142 attached to the first electrode 42 connected to the first conductive region 20 functioning as an emitter region. As another modified example, the second insulating part 144b is located to extend to the inside of the overlapping part OP and the first insulating part 144a is located outside the overlapping part OP, so that there are multiple parts within the overlapping part OP. The wiring member 142 may be connected to the first electrode 44 of the second solar cell 10b and may not be connected to the first electrode 42 of the first solar cell 10a. Various other variations are possible.

Figure 12 is a perspective view schematically showing a connection sheet included in a solar cell panel according to another embodiment of the present invention and including a plurality of wiring members connecting first and second solar cells. FIG. 13 is a partial cross-sectional view showing various examples of the connection sheet shown in FIG. 12.

Referring to FIG. 12, a direction (second direction) intersects the plurality of wiring members 142 in a portion corresponding to the overlapping portion (reference numeral OP in FIG. 5, hereinafter the same) of the connection sheet 140 according to the present embodiment. A pad electrode 1420 extending long may be provided. The pad electrode 1420 is located between the front side of the first solar cell (reference numeral 10a in FIG. 7, hereinafter the same) and the back side of the second solar cell (reference numeral 10b in FIG. 7, hereinafter the same) in the overlap portion OP. This is a part to be connected to the first electrode of the first solar cell 10a (reference numeral 42 in FIG. 7, hereinafter the same) and the second electrode (reference numeral 44 in FIG. 7, hereinafter the same) of the second solar cell 10b. . The connection sheet 140 and the first electrode 42 of the first solar cell 10a and the second electrode 44 of the second solar cell 10b are connected within the overlap portion OP by the pad electrode 1420. Physical and electrical connections can be made reliably.

The line width of the pad electrode 1420 in the first direction may be equal to or larger than the diameter or width of the wiring member 142 in the second direction. Alternatively, the thickness of the pad electrode 1420 may be equal to or greater than the diameter or thickness of the wiring member 142. In particular, the line width of the pad electrode 1420 in the first direction may be larger than the diameter or width of the wiring member 142 in the second direction. As a result, the first and second solar cells 10a and 10b can be stably connected. The pad electrode 1420 may include an electrically conductive material (eg, metal), and may have the same material as the plurality of wiring members 142 or a different material from the plurality of wiring members 142.

At this time, as shown in (a) of FIG. 13, the plurality of wiring members 142 are located through the pad electrode 1420, or the pad electrodes 1420 are located on both sides of the plurality of wiring members 142. You can. In this case, the first and second insulating parts 144a and 144b may be respectively located in areas excluding the pad electrode 1420. However, the present invention is not limited to this, and the shape and arrangement of the first and second insulating portions 144a and 144b may be modified in various ways.

Alternatively, as shown in (b) of FIG. 13, the pad electrode 1420 may be located on the rear side of the plurality of wiring members 142. Then, current collection efficiency can be improved by securing a relatively large area of the wiring material 142 attached to the first electrode 42 connected to the first conductive region 20 functioning as an emitter region. In FIG. 13(c) , the first insulating portion 144a located on the opposite side of the pad electrode 1420 is illustrated extending to the overlapping portion OP, but the present invention is not limited thereto. Accordingly, the shape and arrangement of the first and second insulating portions 144a and 144b may be changed in various ways.

Alternatively, as shown in (c) of FIG. 13, the pad electrode 1420 may be located on the front side of the plurality of wiring members 142. 13 illustrates that the second insulating portion 144b located on the opposite side of the pad electrode 1420 extends to the overlap portion OP to maximize the area protecting the plurality of wiring members 142 on the outer surface side. The invention is not limited to this. Accordingly, the shape and arrangement of the first and second insulating portions 144a and 144b may be changed in various ways.

Figure 14 is a plan view showing two solar cells formed by cutting one mother solar cell according to another embodiment of the present invention. For clear understanding, the enlarged view of FIG. 14 schematically shows the wiring material to be attached to the first solar cell with a dashed-dotted line.

Referring to FIG. 14, in this embodiment, the bus bars 42b and 44b of the first and/or second electrodes 42 and 44 do not have pad portions (reference numerals 422 and 442 in FIG. 3, hereinafter the same). It may be provided with line portions 421 and 441. According to this, as shown in the enlarged circle of FIG. 14, the wiring material 142 included in the connection sheet (reference numeral 140 in FIG. 1, hereinafter the same) is attached to the line portions 421 and 441 or is attached to the line portion 421. , 441) and may be electrically and/or physically connected to the first and/or second electrodes 42 and 44. Since the pad portions 422 and 442 are not provided, the material cost of the electrodes 42 and 44 can be reduced and light loss incident into the solar cell 10 can be minimized. In this embodiment, the wiring member 142 is located in the minor axis direction, and the connection sheet 140 including the wiring member 142 is connected to the first and second solar cells 10a by an adjacent portion (for example, an overlapping portion OP). , 10b) and can be stably fixed to the first and second solar cells 10a and 10b. Accordingly, the electrical and/or physical connection of the wiring member 142 can be stably implemented even without the pad portions 422 and 442.

Figure 15 is a plan view showing two solar cells formed by cutting one mother solar cell according to another embodiment of the present invention. For clear understanding, the enlarged view of FIG. 15 schematically shows the wiring material to be attached to the first solar cell with a dashed-dotted line.

Referring to FIG. 15, in this embodiment, the first and/or second electrodes 42 and 44 do not have bus bars (reference numerals 42b and 44b in FIG. 3 or FIG. 14) and are connected to finger lines 42a and 44a. can be provided. In the drawings attached to this specification, it is illustrated that a border line (L) connecting the ends of the finger lines (42a, 44a) is provided, but it is also possible not to provide a separate border line (L). According to this, as shown in the enlarged circle of FIG. 15, the wiring material 142 included in the connection sheet 140 is attached to the finger lines 42a and 44a or placed on the finger lines 42a and 44a to form the first and/or may be electrically and/or physically connected to the second electrodes 42 and 44. In this embodiment, the wiring member 142 included in the connection sheet 140 serves as an interconnector connecting the first and second solar cells 10a and 10b, and serves as a current collection electrode or carrier for collecting current. It can directly perform the role of a bypass electrode that provides a bypass path.

In this way, since the bus bars 42b and 44b are not provided, the material cost of the electrodes 42 and 44 can be reduced and the loss of light incident into the solar cell 10 can be minimized. In this embodiment, the wiring member 142 is located in the minor axis direction, and the connection sheet 140 including the wiring member 142 is connected to the first and second solar cells 10a by an adjacent portion (for example, an overlapping portion OP). , 10b) and can be stably fixed to the first and second solar cells 10a and 10b. Accordingly, the electrical and/or physical connection of the wiring member 142 can be stably implemented even without the bus bars 42b and 44b.

Figure 16 is a partial cross-sectional view schematically showing a plurality of solar cells and connection sheets included in a solar cell panel according to another embodiment of the present invention.

Referring to FIG. 16, the first and second solar cells 10a and 10b are in contact with each other in the first direction to form adjacent portions, and in this adjacent portion, the front surface of the first solar cell 10a and the second solar cell The middle portion (reference numeral 1421 in FIG. 4 ) of the wiring member 142 of the connection sheet 140 is located between the rear surfaces of (10a, 10b). In FIG. 16 , when viewed in cross section, the side surfaces of the first solar cell 10a adjacent to each other in the first direction are shown to coincide with the side surfaces of the second solar cell 10b adjacent thereto, but the present invention is not limited thereto. . Accordingly, when viewed in plan, the edge of the adjacent first solar cell 10a and the edge of the adjacent second solar cell 10b may be in contact with each other, so that the distance between them is substantially 0.

According to this, the first and second solar cells 10a and 10b do not have an overlapping portion OP, but the first and second solar cells 10a and 10b are not spaced apart from each other in the first direction, so that the first and second solar cells 10a and 10b The distance between the two solar cells 10a and 10b may be substantially zero. Accordingly, the number of solar cells 10 included in the solar cell panel 100 can be maximized, the area occupied by the solar cells 10 can be maximized, and the area of the dead area due to the overlap portion OP can be minimized. The shape and arrangement of the first and second insulating parts 144a and 144b included in the connection sheet 140 are not limited to those shown in FIG. 16 and may be modified in various ways.

In the above-described embodiments, except for the description related to the overlapped portion OP having a constant width, the description related to the overlapped portion OP can be directly applied to the adjacent portion of the present embodiment.

In the above-described embodiment, the neighboring solar cells 10 have an overlapping portion (OP) or are positioned so that their side surfaces coincide with each other, so that there is no gap between the neighboring solar cells 10. However, the present invention is not limited to this. As a modified example, as shown in FIG. 17, neighboring first and second solar cells 10a and 10b are positioned with a distance between them, but the second solar cell is located above the first solar cell 10a. At least a portion of 10b may be located ahead of the first solar cell 10a. At this time, since the distance between the first and second solar cells 10a and 10b is very small, the positional relationship between the above-described first and second solar cells 10a and 10b may be maintained, and a separate structure, etc. may be used. The positional relationship between the above-described first and second solar cells 10a and 10b may be maintained. In this case as well, since the wiring material 142 or the connection sheet 140 including the same is not located between the side surfaces of the first and second solar cells 10a and 10b, The distance can be minimized. The shape and arrangement of the first and second insulating parts 144a and 144b included in the connection sheet 140 are not limited to those shown in FIG. 17 and may be modified in various ways.

Figure 18 is a perspective view schematically showing a solar cell panel according to another embodiment of the present invention. For simplicity of illustration, the wiring member 142 connecting the plurality of solar cells 10 is shown only in the enlarged view of FIG. 18 .

Referring to FIG. 18, in this embodiment, the mother solar cell itself can be used as the solar cell 10 without cutting the mother solar cell, and/or the connection sheet 140 connecting adjacent solar cells 10 ) may have a relatively wide width (for example, exceeding 1 mm) or may have a square cross-section where the width is greater than the thickness. As an example, the wiring material 142 may be composed of a ribbon. As a result, the mother solar cell can be used as is, no cutting process is required, and the manufacturing process can be simplified by using a ribbon. In this way, the structure of the solar cell 10, the structure of the wiring member 142, etc. may be modified in various ways. Additionally, in the present invention, wires, connection members, interconnectors, etc. of various structures can be used as the wiring material 142.

In this embodiment, the neighboring solar cells 10 have an overlapping part (OP) or are arranged so that their side surfaces match, and the wiring material 1420 has a thickness of the overlapping part (OP) or an adjacent part of the neighboring solar cell 10. It may be located between solar cells 10 that are adjacent in direction. The positional relationship and connection relationship between the neighboring solar cells 10 and the wiring member 142 can be applied as described in the embodiments with reference to FIGS. 1 to 17 .

As a modified example, the solar cell 10 may be used as the mother solar cell itself, and a connection sheet 140 including a wiring member 142 having a small width, diameter, or thickness may be used. As another modified example, a wiring member 142 is cut from the mother solar cell and has a relatively wide width (e.g., exceeding 1 mm) to the solar cell 10 having a long axis and a short axis, or has a square cross-section whose width is greater than the thickness. ) can be used. Various other variations are possible.

The features, structures, effects, etc. described above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

100: solar panel
10: solar cell
140: insulation sheet
142: Wiring material
144a: first insulating portion
144b: second insulating portion
145: Bus Ribbon
OP: overlap

Claims (20)

First and first electrodes are connected to each other in a first direction and each includes a semiconductor substrate, a first electrode located on the front of the semiconductor substrate, and a second electrode located on the back of the semiconductor substrate, and each has a major axis and a minor axis. a plurality of solar cells including two solar cells; and
A plurality of wiring members extending in the first direction to electrically connect the first electrode of the first solar cell and the second electrode of the second solar cell are embedded, and the plurality of wiring members are physically fixed. It includes a connection sheet including an insulating portion integrated with the plurality of wiring members,
The insulating portion includes at least a first insulating portion located on the front surface of the first solar cell, and a second insulating portion located at least on the rear surface of the second solar cell,
The first insulating part is located on the front side of the plurality of wiring members, and the second insulating part is located on the rear side of the plurality of wiring members,
The rear surface of the second solar cell is positioned on the front surface of the first solar cell and has an adjacent portion that contacts or overlaps the first solar cell.
In the connection sheet, the plurality of wiring members extend in the minor axis direction parallel to the first direction and are spaced apart from each other in a second direction intersecting the first direction,
The plurality of wiring members includes a first extension part having a first exposed part located on the rear surface of the first insulating part in a part corresponding to the first solar cell and exposed to the outside from the rear side, and a second solar cell corresponding to the second solar cell. It includes a second extension portion located above the front surface of the second insulating portion in the portion having a second exposed portion exposed to the outside from the front side,
The first electrode includes a plurality of first finger lines extending long in the long axis direction,
The plurality of wiring members extend in the minor axis direction and are positioned to pass through the plurality of first finger lines of the first solar cell,
The second electrode includes a plurality of second finger lines extending long in the long axis direction,
A solar cell panel wherein the second extension portion extends in the minor axis direction and passes through the plurality of second finger lines of the second solar cell. delete delete delete According to paragraph 1,
The connection sheet is a solar cell panel having an adjacent portion where the first insulating portion and the second insulating portion contact or overlap each other corresponding to the adjacent portion. According to clause 5,
A portion of the rear surface of the second solar cell is positioned on the front surface of the first solar cell to form an overlapping portion extending long in the long axis direction,
The connection sheet has an overlapping portion where the first insulating portion and the second insulating portion overlap each other corresponding to the overlapping portion,
A solar cell panel wherein the overlapping portion of the connection sheet is located between the first and second solar cells in the overlapping portion. According to clause 6,
A solar cell panel in which the plurality of wiring members are spaced apart from each other in a second direction intersecting the first direction within the insulating portion and are spaced apart from the first and second solar cells. delete According to paragraph 1,
A solar cell panel in which the plurality of wiring members extend from a rear surface of the second solar cell to a portion other than the adjacent portion and are connected to the second electrode. delete According to paragraph 1,
A solar cell panel in which the connection sheet and the plurality of wiring members each extend long from one side of the front side of the first solar cell opposite the adjacent portion to the other side of the rear surface of the second solar cell opposite the adjacent portion. . According to clause 11,
A solar cell panel wherein the connection sheet and the plurality of wiring members do not each have a portion where the connection sheet and the plurality of wiring members are bent or bent at an acute angle from one side of the front surface of the first solar cell to the other side of the rear surface of the second solar cell. According to clause 11,
A solar cell panel wherein, in the thickness direction of the first or second solar cell, a positional difference between the connection sheet or the plurality of wiring members is smaller than a thickness of the first or second solar cell. According to paragraph 1,
At least one of the first and second electrodes includes a plurality of finger lines formed in a second direction crossing the first direction,
A solar cell panel in which the width or diameter of the wiring member is smaller than the pitch of the plurality of finger lines. According to paragraph 1,
A solar cell panel in which the plurality of wiring members embedded in the connection sheet each have a width or diameter of 400 μm or less and are spaced apart from each other in a second direction intersecting the first direction. According to paragraph 1,
A portion of the rear surface of the second solar cell is positioned on the front surface of the first solar cell to form an overlap extending long in the long axis direction,
A solar cell panel in which the width, diameter, or thickness of the wiring member is smaller than the width of the overlap portion in the minor axis direction. According to paragraph 1,
A portion of the rear surface of the second solar cell is positioned on the front surface of the first solar cell to form an overlap extending long in the long axis direction,
A solar cell panel wherein the width of the overlapping portion in the minor axis direction is 2 mm or less. According to paragraph 1,
A portion of the rear surface of the second solar cell is positioned on the front surface of the first solar cell to form an overlap extending long in the long axis direction,
A solar cell panel in which the distance between the first solar cell and the second solar cell located in the overlap portion in the thickness direction or the thickness of the connection sheet is smaller than the width of the overlap portion in the minor axis direction. According to paragraph 1,
The connection sheet further includes a pad electrode extending in a direction crossing the plurality of wiring members corresponding to the adjacent portion. According to clause 19,
A solar cell panel wherein the line width of the pad electrode is equal to or greater than the width or diameter of the wiring member, or the thickness of the pad electrode is equal to or greater than the thickness or diameter of the wiring member.

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