KR102581911B1 - A back contact solar cell and solar cell module including the same - Google Patents

Abstract

It includes a plurality of rear electrode solar cells stacked in a stepwise manner and a connecting member disposed between the adjacent rear electrode solar cells, wherein each rear electrode solar cell has an overlap portion that overlaps with the adjacent rear electrode solar cell. At least a portion of the overlap portion forms a connection hole, and the connection member electrically connects electrodes of adjacent back electrode solar cells through the connection hole.

Description

Back electrode type solar cell and solar cell module including the same {A BACK CONTACT SOLAR CELL AND SOLAR CELL MODULE INCLUDING THE SAME}

The present invention relates to a back electrode type solar cell and a back electrode type solar cell module including the same. More specifically, the present invention relates to a back electrode type solar cell that is modularized by forming connection holes in a plurality of back electrode type solar cells, overlapping them, and stacking them in steps.

Solar cells can be manufactured by forming various layers and electrodes according to design, and solar cell efficiency can be determined according to the design of these various layers and electrodes.

In the case of a back electrode type solar cell, the electrodes are all placed on the back of the solar cell, so in order to modularize the back electrode type solar cell, many components such as pattern films, ribbons, and pastes are required while controlling the space between multiple solar cells. Therefore, there has been a need for modularization of rear electrode type solar cells with a simple structure and few processes.

The technical problem to be solved by the present invention is to provide a back electrode type solar cell that can improve power generation efficiency with a simple structure and few processes and a back electrode type solar cell module including the same.

The technical problem to be solved by the present invention is to provide a back electrode type solar cell module by forming a connection hole in a back electrode type solar cell and stacking a plurality of solar cells in a stepwise manner using a connection member.

The technical problem that the present invention aims to solve is a rear electrode type in which the rear electrode of the upper solar cell and the rear electrode of the lower solar cell are electrically connected through a connection hole by a connecting member for a plurality of solar cells stacked in a stepwise manner. The goal is to provide solar cell modules.

In order to solve the above-described technical problem, in some embodiments of the present invention, the rear electrode type solar cell specifies an overlap portion that overlaps the adjacent upper solar cell and the lower solar cell, and forms a connection hole.

In addition, in order to solve the above-mentioned technical problem, the rear electrode solar cell module according to some embodiments of the present invention connects adjacent rear electrode solar cells by placing a connecting member in the overlap portion, and the rear electrode of the upper solar cell , the conductive adhesive portion, the electrode portion disposed inside the connection hole, and the back electrode of the lower solar cell are electrically connected.

The present invention reduces CMT (Cell to module loss), improves temperature coefficient and hot-spot durability, and improves solar cell efficiency by forming connection holes in non-power generation areas by manufacturing a plurality of back electrode-type solar cells through cell cutting. You can do it.

In addition, the plurality of back electrode type solar cell modules of the present invention are stacked with solar cells overlapping in a stepped manner, and the back electrode of the adjacent upper solar cell is electrically connected to the back electrode of the lower solar cell by the conductive adhesive portion and electrode portion through the connection hole. As a result, the production process can be simplified, increasing productivity and reducing defect rates.

Furthermore, module output and efficiency can be improved by minimizing the non-power generation area.

1 is a rear view of a rear electrode type solar cell module according to the present invention.
Figure 2 is a perspective view showing a structure in which a rear electrode type solar cell module according to an embodiment of the present invention is combined.
Figure 3 is a cross-sectional view showing a combined structure of a plurality of rear electrode-type solar cells according to an embodiment of the present invention.
Figure 4 is a perspective view showing a rear electrode type solar cell according to an embodiment of the present invention.
Figure 5 is a rear view showing a plurality of photoelectric conversion units 10a.
Figure 6 is a rear view showing rear electrodes formed on a plurality of photoelectric conversion units 10a.
Figure 7 is a rear view showing dividing a plurality of rear electrode type solar cells.

The advantages and features of the present invention and methods for achieving them will become clear with reference to the embodiments described below. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the present invention of the scope of the invention, and that the present invention is defined by the scope of the claims. It just becomes. Like reference numerals refer to like elements throughout the specification.

In the drawing, the thickness is enlarged to clearly express various layers and regions. And in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.

In addition, in this specification, when a part of a layer, membrane, region, plate, etc. is said to be “on” or “on top” of another part, this means not only when it is “right on” another part, but also when there is another part in between. Also includes. Conversely, when a part is said to be “right on top” of another part, it means that there is no other part in between. In addition, when a part of a layer, membrane, region, plate, etc. is said to be “under” or “beneath” another part, this refers not only to being “immediately below” another part, but also to cases where there is another part in between. Includes. Conversely, when a part is said to be "right below" another part, it means that there is no other part in between.

The plurality of rear electrode solar cells 10 of the present invention created through cell cutting include an overlap portion (OP) that overlaps the adjacent upper rear electrode solar cells 10 and lower rear electrode solar cells 10. In addition, the connection hole 13 is formed in the overlap part (OP) to reduce the loss (CMT, cell to module loss) due to future modularization, increase the temperature coefficient and hot-spot durability, and improve the solar cell Efficiency can be improved.

Specifically, when generating a plurality of back electrode type solar cells 10 through cell cutting instead of using one solar cell of a certain area, the area of the unit solar cell is reduced and the current is reduced, but instead of the entire back electrode type solar cell 10 As the number of solar cells 10 increases, the voltage increases.

At this time, the temperature coefficient means the percentage decrease in output due to an increase of 1℃ based on 25℃. As the voltage increases, the temperature coefficient decreases, so excellent output can be produced even at high temperatures. In addition, the rear electrode type solar cell 10 may generate local heat when part of the light-receiving surface is obscured by clouds or external foreign substances, and this heat decreases as the current decreases, effectively improving hotspot durability. .

Furthermore, since the rear electrode type solar cell module 100 can be arranged densely, electrical resistance and optical loss are reduced, and as a result, solar cell output can be maximized even when modularized.

Furthermore, the back electrode type solar cell module 100 according to an embodiment of the present invention includes a plurality of back electrode type solar cells 10 stacked in a stepwise manner, and at the same time, the adjacent upper back electrode type solar cells 10 are stacked. The structure and production process can be simplified as the back electrode is electrically connected to the back electrode of the lower back electrode type solar cell 10 by the conductive adhesive part 14a and the electrode part 14b through the connection hole 13, Solar cell efficiency can be maximized by minimizing optical loss.

Specifically, in order to form a back electrode type solar cell module 100 using a back electrode type solar cell 10, a multi-ribbon busbar (Multi-ribbon busbar) that requires soldering paste and insulation paste because all electrodes are disposed on the back side. riboon busbar (MRB), expensive patterned films, or interconnectors with complex structures had to be used, making the process cumbersome and the structure of the modularized solar cell also complex.

Accordingly, in the rear electrode type solar cell module 100 of the present invention, solar cells are arranged in a stepped manner overlapping each other, so there is no need to form a space between solar cells to prevent electrical short and leakage, thereby maximizing the light receiving area. It is possible to improve solar cell efficiency, and since adjacent solar cells are electrically coupled by the conductive adhesive portion 14a disposed in the overlap portion OP and the electrode portion 14b of the connection hole 13, the process and structure are simple. This is not only advantageous for productivity and production costs, but also reduces the defect rate in the process.

Hereinafter, with reference to the attached drawings, the characteristic contents of the back electrode type solar cell module 100 and the back electrode type solar cell 10 according to an embodiment of the present invention will be described.

First, the rear electrode type solar cell 10 according to an embodiment of the present invention will be described with reference to FIG. 4.

The rear electrode type solar cell 10 of the present invention includes a semiconductor substrate, a first conductivity type region formed on one surface of the semiconductor substrate, and a second conductivity type region having an opposite conductivity type to the first conductivity type region. In the solar cell according to this embodiment, both the first conductivity type region and the second conductivity type region are disposed on one side of the semiconductor substrate, specifically, the back side, and the electrode electrically connected to the first conductivity type region and the second conductivity type region is also All exist on the back side of the semiconductor substrate.

The structure and arrangement shape of the first conductivity type region and the second conductivity type region of the present invention include a range in which a person skilled in the art can easily change the design within the range of forming the back electrode type solar cell 10. something to do.

The rear electrode type solar cell 10 according to this embodiment includes an overlap portion (OP) at the opposing corner portion, and a connection hole 13 may be formed in a portion of the overlap portion (OP).

Specifically, the overlap portion (OP) forms a back electrode type solar cell module 100 to be described later, and when adjacent back electrode type solar cells 10 overlap, a back electrode type solar cell corresponding to the overlapping section ( 10) As a portion, each of the rear electrode solar cells 10 has a first overlap portion OP1 that overlaps the adjacent lower rear electrode solar cell 10 and a second overlap portion OP1 that overlaps the adjacent upper rear electrode solar cell 10. 2 May include an overlap part (OP2).

For example, in a structure in which a plurality of back electrode solar cells 10 are stacked in a stepwise manner in the arrangement direction, one specific back electrode solar cell 10 is connected to the adjacent upper back electrode solar cell 10 and It overlaps the adjacent lower rear electrode type solar cell 10 and includes a first overlap part (OP1) and a second overlap part (OP2), and the first overlap part (OP1) and the second overlap part (OP2) are arranged. They are respectively disposed at the corners of the rear electrode type solar cell 10 so as to face each other in the direction.

In addition, the overlap portion OP according to this embodiment may be a rectangle or a geometric polygon depending on the shape of the rear electrode type solar cell 10. However, the shape of the overlap portion OP is not limited to the above description or drawings, and will include a range in which a person skilled in the art can easily design and change the shape of the overlap portion.

The width of the overlap portion (OP) may be greater than about 1 mm and less than about 15 mm, and more specifically, may be greater than about 1 mm and less than about 10 mm. In this embodiment, by maintaining the width of the overlap portion (OP) within the above range, stable modularization is possible when forming the rear electrode type solar cell module 100 in the future, and at the same time, a large light receiving area can be secured to produce excellent solar cell output. When the width of the overlap portion (OP) is less than 1 mm, the bonding stability of adjacent back electrode type solar cells 10 may be reduced during the modularization process. If the width of the overlap portion (OP) exceeds 15 mm, the light receiving area of the rear electrode type solar cell 10 may be excessively reduced, which may actually reduce solar cell output.

In this specification, the width of the overlap portion (OP) refers to the thickness of the overlap portion (OP) in the direction in which the plurality of back electrode type solar cells 10 are overlapped and arranged, and the thickness of the back electrode type solar cell 10 is non-uniform. If it has, the maximum thickness will be viewed as the width of the overlap part (OP).

Furthermore, the widths of the first overlap part (OP1) and the second overlap part (OP2) may be the same or different from each other, and even when the widths are different, the first overlap part (OP1) is within a range of about 1 mm to about 15 mm. ) and the width of the second overlap portion (OP2) may be different.

The rear electrode type solar cell 10 according to an embodiment of the present invention may have the connection hole 13 formed in at least a portion of the overlap portion OP, and specifically may be formed in the second overlap portion OP2. The connection hole 13 formed in the second overlap portion OP2 is a hole that penetrates the upper and lower surfaces of the rear electrode solar cell 10, and the upper and lower surfaces of the rear electrode solar cell 10 are electrically connected. It can serve as a conduit.

Furthermore, the cross-section of the connection hole 13 may have an irregular shape as well as a geometric polyhedron such as an ellipse or a square, and may have an irregular shape, and may have a shape of a passage electrically connected through the upper and lower surfaces of the rear electrode type solar cell 10. As long as it can play a role, it can include the scope in which an ordinary engineer can easily change the design. For example, the connection hole 13 according to this embodiment may have a circular cross-section.

A plurality of connection holes 13 may be formed in the second overlap part OP2, and may be arranged uniformly at regular intervals, may be clustered in a specific part by dividing the second overlap part OP2, or may be irregularly arranged. It may be formed by being dispersed in the second overlap part OP2.

The formation position and arrangement structure of the connection hole 13 are not limited to the above description and drawings, and will include a range in which a person skilled in the art can easily change the design.

Furthermore, the width of the connection hole 13 may be equal to or smaller than the width of the overlap portion OP. By controlling the width of the connection hole 13 to be equal to or smaller than the width of the overlap portion (OP), the entire connection hole 13 can be stably formed within the overlap portion (OP), effectively without reducing the efficiency of the solar cell module. Solar cell modularization can be implemented.

In this specification, the width of the connection hole 13 will be viewed as the longest length crossing the cross section of the connection hole 13.

Specifically, the width of the connection hole 13 may be greater than about 0.5 mm and less than about 10 mm. In this embodiment, by controlling the range of the width of the connection hole 13 to the above range, a level of resistance that allows smooth electrical connection between adjacent rear electrode type solar cells 10 is minimized and damage caused by the formation of the connection hole 13 is minimized. It can be implemented. If the width of the connection hole 13 is less than about 0.5 mm, the resistance may be too large, resulting in large electrical loss, and if the width of the connection hole 13 is more than about 10 mm, damage due to the formation of the connection hole 13 may be large. The overall durability of the rear electrode type solar cell 10 may be reduced.

Next, the back electrode type solar cell 10 according to this embodiment may include a first electrode 11 and a second electrode 12 respectively connected to the first conductivity type region and the second conductivity type region.

Specifically, the plurality of first electrodes 11 and the second electrodes 12 may be arranged alternately at regular intervals on the back of the semiconductor substrate, and extend in the arrangement direction of the plurality of back electrode-type solar cells 10. It can be. Furthermore, the first electrode 11 overlaps the first overlap part OP1 but does not overlap the second overlap part OP2, and the second electrode 12 overlaps the second overlap part OP2 but does not overlap the second overlap part OP2. 1 It may not overlap with the overlap part (OP1).

Specifically, referring to FIG. 3, the second electrode 12 shown in the drawing is shown to be spaced apart from the first electrode 11 shown in the drawing and is disposed behind the first electrode 11. As shown in the drawing, the second electrode 12 is shown in the drawing. The two electrodes 12 extend further toward the second overlap part OP2 than the first electrode 11 and overlap the second overlap part OP2, but do not overlap the first overlap part OP1 (not shown). .

Conversely, as shown in the drawing, the first electrode 11 extends further toward the first overlap part OP1 and overlaps the first overlap part OP1, but does not overlap the second overlap part OP2.

That is, the rear electrode type solar block according to this embodiment controls the first overlap part (OP1) and the second overlap part (OP2) to be connected to only one of the first electrode 11 or the second electrode 12. By doing so, shunts, etc. can be prevented and solar cell output can be achieved stably.

Furthermore, since it is sufficient for the first electrode 11 and the second electrode 12 to overlap the first overlap part OP1 and the second overlap part OP2, the first electrode 11 and the second electrode 12 may be used as necessary. (12) may be further extended inside the overlap part (OP) or may be overlapped with a pattern in a direction intersecting the arrangement direction within the overlap part (OP).

Next, the rear electrode type solar cell module 100 according to an embodiment of the present invention is a solar cell module implemented using the above-described rear electrode type solar cell 10. Referring to FIGS. 1 to 3 below, the rear electrode type solar cell module 100 is a solar cell module 100 according to an embodiment of the present invention. The electrode-type solar cell module 100 will be described in detail.

The solar cell module according to an embodiment of the present invention stacks the plurality of rear electrode-type solar cells 10 described above by overlapping them in steps. For example, for the reference back electrode type solar cell 10, the adjacent upper back electrode type solar cell module 100 and the adjacent lower back electrode type solar cell module 100 are connected to the reference back electrode type solar cell 10. There is some overlap, where the upper back electrode solar cell 10 partially overlaps the upper part of the reference back electrode solar cell 10, and the lower back electrode solar cell 10 overlaps with the reference rear electrode solar cell 10. They are partially overlapped and stacked at the bottom.

Specifically, the second overlap part (OP2) of the reference back electrode type solar cell 10 and the first overlap part (OP1) of the upper back electrode type solar cell 10 overlap each other, and the reference back electrode type solar cell ( The first overlap part (OP1) of 10) and the second overlap part (OP2) of the lower rear electrode type solar cell 10 overlap each other and are stacked in a stepwise manner.

That is, referring to FIG. 1, the present invention does not arrange a plurality of back electrode type solar cells 10 to be spaced apart from each other, but parts of the back electrode type solar cells 10 are overlapped and stacked continuously to prevent electrical short and leakage ( The light receiving area can be maximized within the rear electrode type solar cell module 100 of a certain area without an area to prevent leakage, etc., and as a result, the production output of the solar cell module can be improved.

Furthermore, the embodiment according to the present invention can help solar cell output by forming the connection hole 13 in the second overlap portion OP2 that overlaps during the modularization process. Specifically, when forming the connection hole 13 penetrating the rear electrode type solar cell 10, some physical shock or chemical degeneration may occur in the area where the connection hole 13 is formed, but the connection hole 13 ) is formed because the second overlap portion (OP2) is overlapped by the upper rear electrode type solar cell 10 anyway during the modularization process and is not exposed to the light-receiving surface, so there is no decrease in solar cell output due to the formation of the connection hole 13. Rather, it is possible to maximize the light receiving area within a solar cell module of a certain area.

Additionally, in this specification, the upper back electrode type solar cell 10 and the lower back electrode type solar cell 10 are among the plurality of back electrode type solar cells 10 arranged in a stepped manner, with some overlapping, as described above. , It will be said to mean a rear electrode solar cell 10 disposed relatively lower and a rear electrode solar cell 10 disposed relatively upper with respect to any rear electrode solar cell 10. , depending on the reference back electrode type solar cell 10, the same back electrode type solar cell 10 may be an upper back electrode type solar cell 10 or a lower back electrode type solar cell 10.

Subsequently, the back electrode type solar cell module 100 according to an embodiment of the present invention includes the first overlap portion OP1 of the adjacent upper back electrode type solar cell 10 and the second overlap portion OP1 of the lower back electrode type solar cell 10. By disposing the connecting member 14 between the overlap portions OP2, adjacent back electrode type solar cells 10 can be electrically and physically coupled.

Specifically, referring to FIGS. 2 and 3 , the connecting member 14 may include a conductive adhesive portion 14a and an electrode portion 14b, and, based on the two adjacent rear electrode-type solar cells 10, the upper rear surface The conductive adhesive portion 14a may be disposed entirely between the first overlap portion OP1 of the electrode-type solar cell 10 and the second overlap portion OP2 of the lower rear electrode-type solar cell 10.

In this specification, the term "placed as a whole" includes not only the complete physical arrangement in the relevant area or space, but also cases where some parts are inevitably excluded.

The conductive adhesive portion 14a contains a polyblend such as epoxy acrylic fluoride, silicone, and polyamide and has adhesive properties, so it physically and stably bonds the adjacent rear electrode type solar cell 10 and has conductive properties. , It can function to electrically connect adjacent rear electrode type solar cells 10. The conductive adhesive portion 14a may be made of various materials. For example, it may be made of electrical conductive adhesive (ECA). However, the type of the conductive adhesive portion 14a is not limited to what is described, and can include a range that can be easily selected by a person skilled in the art as long as it can physically and electrically connect the adjacent back electrode type solar cell 10. .

Additionally, the electrode portion 14b may be entirely disposed inside the connection hole 13 and on one surface of the second overlap portion OP2 in contact with the second electrode 12. The electrode portion 14b disposed entirely on one surface of the second overlap portion OP2 may be formed to cover the second electrode 12 and may be disposed to fill the inside of the connection hole 13.

Since the electrode portion 14b contains a metal material (eg, Ag, Cu, Al) and has conductive properties, it can be effectively electrically connected to the second electrode 12.

However, the arrangement of the conductive adhesive portion 14a and the electrode portion 14b is not limited to the above description and drawings, and may include a range in which a person skilled in the art can easily change the design. For example, the conductive adhesive portion 14a may be disposed not only between the overlap portions (OP) of adjacent rear electrode type solar cells 10 but also inside the connection hole 13, and the electrode portion 14b may be disposed as a second electrode ( 12) may be disposed only on one side of the overlapped second overlap portion OP2.

Next, the electrical connection by the conductive adhesive portion 14a will be described in detail using FIGS. 2 and 3. The first electrode 11 is overlapped on the back first overlap portion OP1 of the upper back electrode type solar cell 10, and the second overlap portion OP2 on the back side of the lower back electrode type solar cell 10 is overlapped with the first electrode 11. The two electrodes 12 overlap and a connection hole 13 is formed in the second overlap portion OP2.

At this time, if the conductive adhesive portion 14a is disposed entirely between the first overlap portion OP1 of the upper rear electrode solar cell 10 and the second overlap portion OP2 of the lower rear electrode solar cell 10, Since the first electrode 11 of the upper back electrode type solar cell 10 overlaps the first overlap portion OP1 of the upper back electrode type solar cell 10, the first electrode 11 and the conductive adhesive portion 14a ) can be electrically connected.

The second electrode 12 of the lower rear electrode type solar cell 10 overlaps the second overlap part OP2, and the electrode part 14b fills the inside of the connection hole 13, and simultaneously overlaps the second overlap part OP2. It may be disposed entirely on the lower surface of the portion OP2 and electrically connected to the second electrode 12.

That is, the conductive adhesive portion 14a electrically connected to the first electrode 11 of the upper back electrode solar cell 10 is an electrode portion electrically connected to the second electrode 12 of the lower rear electrode solar cell 10. By contacting (14b), the upper back electrode type solar cell 10 and the lower back electrode type solar cell 10 can be electrically and physically connected.

Therefore, the back electrode type solar cell module 100 according to an embodiment of the present invention is formed by stacking a plurality of back electrode type solar cells 10 in a stepped manner using the connecting member 14 as described above, thereby increasing productivity. can improve and reduce the defect rate.

Specifically, the rear electrode-type solar cell module 100 according to an embodiment of the present invention can be simply implemented using only the connecting member 14 without separate complex interconnectors, electrode pattern films, and ribbons, so the production process is simple. This simplicity not only improves productivity, but also reduces production costs by reducing the configuration required for the module.

Furthermore, in order to modularize the conventional back electrode type solar cell 10, the defect rate was relatively high because the ribbon had to be aligned using soldering paste and insulating paste, etc. However, the back electrode type solar cell module of the present invention (100) ) can implement modularization only by simple overlapping of steps using the connecting member 14, thereby dramatically reducing the defect rate.

Hereinafter, the back electrode type solar cell 10 and the manufacturing method of the back electrode type solar cell module 100 using the same according to the present invention will be described. Since the above description may be applied as is to parts that are the same or extremely similar to the above description, detailed description will be omitted and only the 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.

Specifically, the back electrode type solar cell 10 and the method of manufacturing the back electrode type solar cell module 100 using the same will be described with reference to FIGS. 5 to 7.

5 to 7 are process diagrams specifically showing the manufacturing process of the back electrode type solar cell 10 and the back electrode type solar cell module 100.

First, Figure 5 is a rear view showing a plurality of photoelectric conversion units 10a divided within a certain area. In this specification, the photoelectric conversion unit 10a may refer to the state before the back electrode is formed in the back electrode type solar cell 10, and the photoelectric conversion unit 10a includes the semiconductor substrate, the first conductivity type region, and the first conductivity type solar cell 10. 2 It may contain a conductive region.

Referring to FIG. 5, in relation to the plurality of photoelectric conversion units 10a divided within a certain area, each photoelectric conversion unit 10a has a first overlap portion at the corner facing each other in the arrangement direction of the plurality of photoelectric conversion units 10a. (OP1) and a second overlap part (OP2) may be formed, and a plurality of connection holes 13 may be formed in the second overlap part (OP2).

The first overlap part (OP1) and the second overlap part (OP2) of the adjacent photoelectric conversion unit (10a) have the same width, and the connection hole (13) is formed using laser drilling by irradiating the first laser. It can be formed by doing so. In the present invention, even though physical shock or chemical crystalline deformation may be caused to the photoelectric conversion unit 10a by forming a plurality of connection holes 13 in the second overlap portion OP2, as described above, other rear surfaces may be used in a later process. Since it is overlapped by the electrode-type solar cell 10 and is not exposed to the light-receiving surface, solar cell efficiency is not impaired.

Next, forming the back electrode type solar cell 10 by forming a back electrode on the photoelectric conversion unit 10a will be described. Figure 6 is a rear view showing the formation of a rear electrode in each of the plurality of photoelectric conversion units 10a.

First electrodes 11 and 2 are electrically connected to the first conductivity type region and the second conductivity type region in the plurality of photoelectric conversion units 10a in which the connection holes 13 are formed, and are alternately arranged at a certain distance from each other. Electrodes can be formed

The first electrode 11 and the second electrode 12 extend in the arrangement direction of the plurality of back electrode type solar cells 10, and the first electrode 11 overlaps the first overlap portion OP1 but the second electrode 11 overlaps the first overlap portion OP1. It does not overlap with the overlap part OP2, and the second electrode 12 overlaps with the second overlap part OP2 but does not overlap with the first overlap part OP1.

The first electrode 11 and the second electrode 12 may be formed using various methods such as plating and printing, and may include a range that a person skilled in the art can easily select to form the electrode. .

Additionally, the order of forming the connection hole 13 of the photoelectric conversion unit and the first electrode 11 and the second electrode 12 is not limited to the order described above, and is limited to the extent that a person skilled in the art can easily change the design. It can be included.

For example, the connection hole 13 may be formed after forming the first electrode 11 and the second electrode 12 in the photoelectric conversion unit 10a.

Next, dividing the plurality of rear electrode type solar cells 10 divided within a certain area will be described. FIG. 7 is a rear view showing dividing a plurality of rear electrode type solar cells 10.

The plurality of back electrode type solar cells 10 formed up to the first electrode 11 and the second electrode 12 have a second overlap portion (OP2) and a first overlap portion (OP1) of the adjacent back electrode type solar cell 10. ) can be divided by a boundary between.

Specifically, the second laser may be irradiated along the dividing line CL between the second overlap portion OP2 and the first overlap portion OP1 of the adjacent rear electrode type solar cell 10 to separate them.

One embodiment of the present invention divides the photoelectric conversion unit 10a having a first area to form a plurality of rear electrode-type solar cells 10 having a second area, resulting in loss due to modularization (Cell to module loss). CTM), temperature coefficient decreases, hot-spot durability increases, and solar cell efficiency can be improved.

Specifically, when the photoelectric conversion unit 10a having a first area is divided to form a plurality of back electrode type solar cells 10, a plurality of back electrode type solar cells 10 having a second area smaller than the first area are formed. ) can be created.

The plurality of rear electrode-type solar cells 10 of the second area formed in this way can later be electrically connected in series by forming a stepwise overlapping stacked structure. In the rear electrode solar cell module 100 according to an embodiment of the present invention, the number of rear electrode solar cells 10 increases and the area of the rear electrode solar cell 10 increases compared to the case where no separate division is performed. As the voltage decreases, the overall voltage of the rear electrode type solar cell module 100 increases and the amount of current decreases.

Therefore, the temperature coefficient, which indicates a decrease in output due to an increase in temperature, may decrease due to the increased voltage. In addition, even if heat is generated locally due to the external environment due to the reduced amount of current, hotspot durability can be improved by reducing the generated heat. Additionally, since a plurality of divided rear electrode type solar cells 10 are combined without space between each other, electrical resistance can be reduced, the light receiving surface can be maximized, and losses due to modularization can be minimized.

Next, referring again to FIG. 7, the manufacturing of the back electrode type solar cell module 100 by modularizing a plurality of divided back electrode type solar cells 10 will be described.

The electrode portion 14b is disposed on the surface of the second overlap portion OP2 overlapping the second electrode 12 and the connection hole 13 using the electrode portion 14b. The electrode portion 14b can be disposed using plating or printing, for example, by printing an electrode paste containing a conductive material on one surface of the second overlap portion OP2 and drying it to form the electrode portion 14b. ), the electrode paste is printed entirely on one surface of the second overlap part (OP2), and at the same time, a part of the electrode paste moves inside the connection hole 13 and fills the connection hole 13. 13) and an electrode portion 14b covering one surface of the second overlap portion OP2 may be formed.

Immediately, the conductive adhesive portion 14a is entirely disposed on the first overlap portion OP1, and the second overlap portion OP2 of the adjacent rear electrode type solar cell 10 is placed on the conductive adhesive portion 14a and attached to the adjacent rear electrode. The type solar cells 10 can be physically coupled and electrically connected.

Since the rear electrode type solar cell module 100 according to this embodiment can be easily modularized using the conductive adhesive portion 14a, low-temperature processing is possible and the possibility of damage to the thin film substrate can be reduced.

Specifically, when using the conductive adhesive portion 14a of this embodiment, for example, ECA, a low-temperature process is possible because the process temperature is less than 250°C, and since the low-temperature process is possible, even if a thin film substrate is used, the possibility of damage during the process is reduced. This can be advantageous in reducing production costs.

However, the method of forming the electrode portion 14b, the formation order of the electrode portion 14b and the conductive adhesive portion 14a, etc. are not limited to the above description, and a person skilled in the art can overlap the rear electrode type solar cell 10 in steps. This will include things that can be easily changed in design within the range that can be stacked.

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.

10: rear electrode type solar cell 11: first electrode
12: second electrode 13: connection hole
14: Connecting member OP: Overlap part

Claims (12)

A plurality of rear electrode-type solar cells stacked in a stepped manner; and
It includes a connecting member disposed between the adjacent rear electrode type solar cells,
Each back electrode solar cell includes an overlap portion that overlaps an adjacent back electrode solar cell,
At least a portion of the overlap portion forms a connection hole,
The connecting member electrically connects the electrodes of the adjacent back electrode type solar cells through the connection hole,
The overlap portion includes a first overlap portion that overlaps an adjacent lower rear electrode type solar cell, and
It includes a second overlap portion overlapping with an adjacent upper back electrode type solar cell,
The connection hole is formed in the second overlap portion.
Rear electrode type solar cell module.
delete delete According to paragraph 1,
The width of the overlap portion is equal to or greater than the width of the connection hole.
Rear electrode type solar cell module.
According to paragraph 1,
The width of the overlap portion is greater than 1 mm and less than 15 mm.
Rear electrode type solar cell module.
According to paragraph 4,
The width of the connection hole is more than 0.5 mm and less than 10 mm.
Rear electrode type solar cell module.
According to paragraph 1,
The connecting member includes a conductive adhesive portion and an electrode portion,
The conductive adhesive portion is disposed entirely between the second overlap portion of the lower back electrode solar cell and the first overlap portion of the upper back electrode solar cell.
Rear electrode type solar cell module.
In clause 7,
The electrode portion is inside the connection hole and
disposed entirely on one side of the second overlap portion.
Rear electrode type solar cell module.
In clause 7,
The electrode portion and the conductive adhesive portion are in contact with each other.
electrically connected
Rear electrode type solar cell module.
In clause 7,
The conductive adhesive portion includes a polymer compound.
Rear electrode type solar cell module.
According to paragraph 1,
The electrode includes a plurality of first electrodes and second electrodes arranged alternately with each other at regular intervals.
Rear electrode type solar cell module.
According to clause 11,
The first electrode overlaps the first overlap portion and does not overlap the second overlap portion,
The second electrode overlaps the second overlap part and does not overlap the first overlap part.
Rear electrode type solar cell module.