KR102542153B1 - Solar cell module - Google Patents

Abstract

In one example of the present invention, the solar cell module includes a string in which a plurality of piece cells are connected to have an overlapping portion, a first portion disposed in the overlapping portion, and a second portion exposed outside the overlapping portion in the first portion. Hidden It is configured to include tabs.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module in which piece cells are connected in a shingled manner, and more particularly, to a solar cell module in which strings are configured in block units and part of the strings are connected in parallel.

A solar cell configures a string to produce a large amount of electricity, and the string is packaged to prevent moisture permeation and to be protected from external impact so that it can be used in an external environment. We call such a packaged string a solar cell module.

As one of the methods of stringing solar cells, a shingled method has been proposed to increase output. This shingled method refers to a method in which solar cells are partially overlapped and connected. When connecting solar cells in the shingled method, solar cells called piece cells can be used. This piece cell is made by dividing 1/n solar cells (hereinafter referred to as mother cells) produced to have a standardized size when solar cells are produced in a factory.

However, when a string composed of piece cells is electrically connected to an adjacent string, since the piece cells are connected in a shingled manner, it is difficult to connect a part of a string to a part of a neighboring string.

The present invention has been created in this technical background, and is intended to easily connect a part of a string with a part of an adjacent string.

The present invention has been conceived from such a technical background, and in one example, a solar cell module includes a string in which a plurality of piece cells are connected to have an overlapping portion, a first portion disposed in the overlapping portion, and a first portion disposed outside the overlapping portion in the first portion. It is configured to include a hidden tab including the exposed second portion.

The string may include the hidden tap, and may include a plurality of strings arranged in parallel with another neighboring string, and a second portion of the hidden tap may be commonly connected to the plurality of strings.

The solar cell module may further include a line-shaped interconnector extending in one direction, and the interconnector may be connected to the second part in each of the plurality of strings.

A second portion of the hidden tap may protrude from the first portion in a longitudinal direction of the string.

The second part of the hidden tap may protrude between strings from each string toward another neighboring string, and the two neighboring strings may be connected such that the protruding second part overlaps between the two strings.

The hidden tab and the interconnector may be formed of one of a ribbon composed of a conductor and solder covering the conductor, or a conductive film composed of an insulating substrate and conductive particles distributed inside the insulating substrate.

The solar cell module may further include an insulating member disposed between the second part of the hidden tab and the rear surface of the string.

In the string, a plurality of cell units including n first sliced cells having long and short sides and m second sliced cells having chamfers at portions of corners may be repeatedly disposed.

The cell unit may have a hexagonal shape including two first piece cells and one second piece cell.

The cell unit may have an octagonal shape including four first piece cells and two second piece cells.

The string may be divided into at least two or more cell blocks obtained by dividing the plurality of fragment cells into the same number, and the hidden tap may be disposed between each cell block.

In one embodiment of the present invention, since a hidden tap exposed to the rear surface of a string is installed for each cell block unit, it is possible to simply connect a string with an adjacent string in cell block units.

1 is a view showing a cross-sectional configuration of a solar cell module according to an embodiment of the present invention.
2 is a diagram showing a string according to an embodiment of the present invention.
3 and 4 are diagrams showing other examples of cell units.
5 is a view showing a plan view of a first piece cell and a second piece cell.
6 is a cross-sectional view showing an interlayer configuration of a piece cell.
7 is a diagram conceptually illustrating a process of forming a first piece cell and a second piece cell from a solar cell.
8 is a view showing an entire front view of an exemplary solar cell module.
9 is a view showing a rear view in which two cell blocks adjacent to each other are connected in parallel around a hidden tap.
FIG. 10 is a view showing a cross-sectional view taken along line II′ of FIG. 9 .
11 and 12 are views showing how two adjacent strings are connected in parallel by an edge connector and an interconnector at the beginning and end of the string.
13 is a diagram showing a physical configuration of a solar cell module according to an example.
FIG. 14 is a diagram showing an equivalent circuit configuration of FIG. 13 .
15 to 17 are planar views of solar cell modules connected by hidden taps according to another example.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention.

However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly explain the present invention in the drawings, parts irrelevant to the description may be simplified or omitted. In addition, various embodiments shown in the drawings are presented by way of example, and for convenience of description, components are simplified and shown differently from actual ones.

In the following detailed description, the same reference numerals are assigned to substantially the same components according to embodiments, and description is given only when necessary.

1 is a view showing a cross-sectional configuration of a solar cell module according to an embodiment of the present invention. Referring to this drawing, the overall configuration of a solar cell module according to an embodiment will be schematically described.

Referring to FIG. 1 , a solar cell module 100 according to an embodiment of the present invention, referring to FIG. 1 , a solar cell module 100 according to an embodiment of the present invention includes a plurality of piece cells 10 It is configured to include a string ST connected to have an overlapping portion, and a hidden tab 51 located in an overlapping portion of two adjacent piece cells and installed not to be visible from the front. Here, the overlapping portion is a region partially overlapped and arranged so that two adjacent piece cells can be electrically and physically connected. In one example, the overlapping portion can be created by connecting two neighboring piece cells in a shingled manner.

The string ST is an array in which a plurality of piece cells 10 are connected in a shingled manner. In one example, the string ST may be divided into cell blocks 31 and connected to adjacent strings, and the cell block A hidden tap 51 may be disposed for each unit.

The hidden tap 51 may be disposed between two adjacent cell blocks 31 to electrically and physically connect the cell blocks 31 to each other. One end 51a of the hidden tap 51 is disposed in the overlapping portion to electrically and physically connect two adjacent piece cells 31a and 31b, and the other end 51b is exposed outside the overlapping portion to form a cell block 31 unit. Provides an interface through which a string can be connected to its neighbors.

The string ST is sealed by a sealant 130, and a first cover member 110 and a second cover member 120 are positioned on the front and rear surfaces, respectively, to form a module.

The first cover member 110 may be disposed on the front surface of the string ST, more precisely, it is located on the surface of the sealing material 130 disposed on the front surface of the string ST, and the second cover member 120 is disposed on the string ( It is disposed on the rear surface of the ST (more precisely, on the surface of the sealant 130 disposed on the rear surface of the string ST).

Each of the first cover member 110 and the second cover member 120 may be made of an insulating material capable of protecting the string ST from external impact, moisture, ultraviolet rays, and the like. Also, the first cover member 110 may be made of a light-transmitting material through which light may pass, and the second cover member 120 may be made of a sheet made of a light-transmitting material, a non-transmissive material, or a reflective material. For example, the first cover member 110 may be made of a glass substrate having excellent durability and excellent insulation properties, and the second cover member 120 may be made of a film or sheet. In this case, the second cover member 120 may be made of a The cover member 120 has a TPT (Tedlar/PET/Tedlar) type, or polyvinylidene fluoride (PVDF) formed on at least one surface of a base film (eg, polyethylene terephthalate (PET)). A resin layer may be included.

The sealant 130 is physically and chemically bonded to the string ST to prevent inflow of moisture and oxygen.

The sealant 130 may be made of an insulating material having light-transmitting and adhesive properties. For example, ethylene-vinyl acetate copolymer resin (EVA), polyvinyl butyral, silicon resin, ester-based resin, or olefin-based resin may be used as the sealant 130 . The sealant 130 may constitute the solar cell module 100 by being integrated with the first and second cover members 110 and 120 through a lamination process or the like.

Hereinafter, a string according to an embodiment of the present invention will be described in more detail with reference to FIG. 2 . 2 is a diagram showing a string according to an embodiment of the present invention.

Referring to FIG. 2 , the string ST of this embodiment may be configured to include a plurality of piece cells connected in series. In one example, the string ST may include a plurality of cell blocks 31 , and the cell blocks 31 may be connected to each other by hidden taps 51 . And, the cell block 31 may be configured to include a cell unit 33 composed of pieces cells having the same shape or different shapes. In FIG. 2, the electric cell unit 33 is exemplified by two types of piece cells having different shapes.

In this embodiment, the piece cells are connected in a shingled connection method, and some of the piece cells form the cell unit 33 . Here, the shingled connection refers to a method in which two neighboring piece cells are positioned so as to partially overlap each other and a conductive member is provided in the overlapping portion (hereinafter referred to as an overlapping portion OP) so that the two neighboring piece cells are electrically and physically connected. Here, the conductive member may be, for example, a conductive adhesive in which a conductive material is mixed with an epoxy resin or a solder such as Sn or Pb.

The cell unit 33 may be configured to include two piece cells having different shapes. For example, the first piece cell 11 of a rectangular shape having a long axis and a short axis and a hexagonal shape with chamfers 1a formed at some corners It may be composed of the second piece cell 12 of.

The first piece cell 11 and the second piece cell 12 are preferably formed by dividing the mother cell into 1/n pieces. Preferably, n may be 6. When the mother cell is divided into six, it is easy to stably connect the fragment cells, and the output loss can be reduced to a minimum. Here, the mother cell refers to a solar cell that has already been made, including components necessary for solar power generation, a semiconductor substrate forming a pn junction, an emitter, a back surface electric field, and electrodes. The piece cell used in this embodiment may be formed by mechanically dividing a solar cell already made to generate solar power in this way into 1/n pieces.

If the string is composed of the piece cells as described above, manufacturing cost can be effectively reduced and output loss can be minimized because there is no need to change the design of existing equipment or the structure of the solar cell. The output loss has a value obtained by multiplying the resistance by the square of the current in the solar cell. Among the currents in the solar cell, there is a current generated by the area of the solar cell itself. As the area of the solar cell increases, the corresponding current also increases, and eventually the solar cell As the area of , the output loss increases. Accordingly, when a solar cell module is configured with fragment cells made by dividing a mother cell, the current generated from the solar cell is reduced in proportion to the reduced area, and as a result, output loss of the solar cell module can be minimized.

The cell unit 33 is 1/2 of the entire piece cell made from one mother cell, that is, when the mother cell is divided into six, two first piece cells 11 and one second piece cell 12 may consist of This is to improve the design of the cell unit 33, and the shape of the cell unit made of two first piece cells 11 and one second piece cell 12 is when the mother cell is divided in half It may have a shape of, and this shape is the same as the shape of the second piece cell 12.

To this end, in the cell unit 33, two first piece cells 11 and one piece second piece cell 12 are arranged in the order of a first piece cell - a first piece cell - a second piece cell.

The cell block 31 includes a plurality of cell units 33 configured as described above, and preferably, one cell block 31 may include 7 cell units 33 . In this embodiment, the cell block 31 is a unit connected by the hidden tap 51, and the string ST is formed by connecting a plurality of cell blocks 31 by the hidden tap 51. As such, in the present embodiment, the string ST is divided into a plurality of cell blocks 31 and connected by hidden taps 51, so that a part of the string ST (ie, a cell block) can be easily connected to a part of another neighboring string. Can be connected. In one embodiment, the cell block 31 can be connected in parallel to the cell blocks of the adjacent string, and the cell blocks can be connected in parallel by electrically connecting hidden taps. This will be described in detail below.

The hidden tap 51 is disposed at the overlapping portion OP between the end piece cell E1 disposed at one end of the cell block 31 and the front piece cell E2 disposed at the head of the other cell block, so that two neighboring It is arranged to be electrically connected to all of the cell blocks 31. In addition, a part of the hidden tap 51 disposed in the overlapping portion OP is exposed to the rear surface of the string ST, and a connecting member such as an interconnector (not shown) is connected to the exposed portion, so that other strings adjacent to it are connected. It can be electrically connected in common with the cell block of.

In one example, a part of the hidden tap 51 is connected to the front surface of each end piece cell E1, and the other end is connected to the rear surface of the front piece cell E2 so that the cell blocks 31 are connected in series and the cell blocks 31 are connected in series. (31) can be located.

Meanwhile, in the above description, the cell unit 33 is composed of two first piece cells 11 and one second piece cell 12, and is configured to have the same hexagonal shape as the second piece cell 12 as a whole. example explained.

However, the present invention is not limited thereto and the cell unit 33 may be configured in various forms. Cell units 33 of various shapes according to an example are illustrated through FIGS. 3 and 4 .

3 illustrates an octagonal cell unit 33 composed of four first piece cells 11 and two pieces cells 12 . In this example, four first piece cells 11 are continuously connected in a shingled manner, and second piece cells 12 are respectively placed at the front and rear ends of the four first piece cells 11 in a shingled manner. They can be connected to form an octagonal cell unit 33 as a whole.

Since this octagonal shape is substantially the same as the shape of the mother cell, it has the advantage of giving people a sense of stability in terms of design, and also one cell unit 33 using the entire piece cell made from one mother cell. It also has the advantage of being configurable.

4 shows an example in which the cell unit 33 is composed of only the first pieced cells 11 having long and short sides, and in one example, the cell unit 33 is composed of only the first pieced cells 11 as described above. It is also possible, and although not shown, it is also possible that the cell unit is composed of only the second piece cells 12 .

As such, it goes without saying that in the solar cell module of the present invention, the cell unit 33 may be arranged to have various shapes not described as well as the examples described herein unless there is a particular limitation.

Hereinafter, the first and second piece cells will be described in detail with reference to FIG. 5 . 5 is a plan view of a first piece cell and a second piece cell, (A) shows a first piece cell, (B) shows a second piece cell, and in FIG. 5 one piece cell If, for example, it is shown to show the rear.

The first piece cell 11 has a rectangular shape having a short side 11a in a first direction (x-axis direction in the drawing) and a long side 11b in a second direction (y-axis direction in the drawing). Although described later, the first piece cells 11 may be formed by dividing a partial region of a mother cell into a plurality of cells. Here, the aspect ratio (short side/long side) of the long side 11b and the short side 11a is preferably 1/2 to 1/12, more preferably 1/6.

A first electrode 42 is disposed on the rear surface of the first piece cell 11 . In a preferred form, the first electrode 42 includes a plurality of first finger electrodes 42a disposed at a predetermined distance from those adjacent to each other in the second direction (y-axis direction in the drawing) and ends of the first finger electrodes 42a. It may include a first bus bar electrode 42b formed long in the second direction while connecting the .

The plurality of first finger electrodes 42a extend from one short side toward the other short side in a first direction (x-axis direction in the drawing) and are spaced apart from neighboring ones in a second direction.

In addition, the first bus bar electrode 42b is disposed along one long side and disposed adjacent to one long side rather than the other long side to connect the ends of the plurality of first finger electrodes 42a. The first bus bar electrode 42b not only electrically connects the plurality of first finger electrodes 42a, but also functions as a pad. Here, the pad refers to an interface that allows two adjacent piece cells to be electrically and physically connected when connecting adjacent piece cells in a shingled manner.

Therefore, in a preferred form, it is preferable that the line width of the first bus bar electrode 42b is greater than the line width of the first finger electrode 42a in order to improve physical and electrical connection, but the present invention is not limited thereto. For reference, the figure shows that the entire line width of the first bus bar electrode 42b is formed to be larger than the line width of the first finger electrode 42a, and in another form, the first bus bar electrode 42b is the first finger electrode A pad having the same line width as the first bus bar electrode and partially formed to have a line width thicker than the line width of the first bus bar electrode may be separately provided.

According to this configuration, when two piece cells are connected in the shingled connection method, the first bus bar electrode 42b of one piece cell is disposed along the overlapping portion, and the pad (or Another bus bar electrode) is located and the two piece cells can be electrically and physically connected by a conductive member.

The second piece cell 12 has substantially the same configuration as the first piece cell 11, that is, all elements constituting the cell (eg, a semiconductor substrate or emitter forming a pn junction, a back surface electric field, etc.) It is configured identically, and there is a slight difference only in shape.

The second sliced cell 12 is different from the first sliced cell 11 in that some of the corners where the long side 12b and the short side 12a meet have a chamfer 1a and have a hexagonal shape close to a rectangle as a whole. There is a difference.

In the second piece cell 12, the first bus bar electrode 42b is preferably arranged to be adjacent to the other side long side 12b facing the one side where the chamfer 1a is formed. When connecting a plurality of piece cells in a shingled connection method, it is convenient to connect the piece cells only when a rear portion of a new piece cell is sequentially arranged to form an overlapping portion with a front portion of a previous piece cell. By the way, in this embodiment, the second piece cell 12 constitutes the cell unit 33 like the first piece cell 11, and in this cell unit 33, the second piece cell is the same as the second piece cell. In order to form a shaped cell unit, they are arranged in the last order. Therefore, it is preferable that the second bus bar electrode 44b functioning as a pad on the rear surface of the second piece cell 12 is disposed adjacent to the other long side.

The first and second piece cells having such an electrode configuration may be configured as a double-sided light-receiving solar cell capable of receiving both light incident on the front and rear surfaces of the mo cell by being configured as illustrated in FIG. 6 .

The solar cell 10 includes a semiconductor substrate 12, conductive regions 20 and 30 formed on or on the semiconductor substrate 12, and electrodes 42 and 44 connected to the conductive regions 20 and 30. ), and the solar cell 10 of this embodiment may be a crystalline solar cell based on the semiconductor substrate 12 . For example, 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 region 20 and a second conductivity type region 30 . A first electrode 42 connected to the conductive region 20 and a second electrode 44 connected to the second conductive region 30 may be included.

The semiconductor substrate 12 includes a first or second conductivity-type dopant at a relatively low doping concentration, and may be a crystalline type, eg, a single-crystal silicon or poly-crystal silicon substrate. In this case, at least one of the front and rear surfaces of the semiconductor substrate 12 may be provided with a texturing structure or an anti-reflection structure having irregularities in the shape of a pyramid or the like to minimize reflection. In the drawing, a case in which irregularities are formed on both the front and rear surfaces according to the double-sided light-receiving solar cell is exemplified.

The conductive regions 20 and 30 are located on one surface (eg, the front surface) of the semiconductor substrate 12 and have a first conductivity type region 20 and the other surface of the semiconductor substrate 12 (For example, the other surface) may include a second conductivity type region 30 having a second conductivity type. The conductive regions 20 and 30 may have a conductivity type different from that of the semiconductor substrate or may have a higher doping concentration than that of the semiconductor substrate 12 . In this embodiment, the first and second conductivity type regions 20 and 30 are constituted as doped regions constituting a part of the semiconductor substrate 12, so that bonding characteristics with the semiconductor substrate 12 can be improved. In this case, the first conductivity type region 20 or the second conductivity type region 30 may have a homogeneous structure, a selective structure, or a local structure.

However, the present invention is not limited thereto, and at least one of the first and second conductive regions 20 and 30 may be formed separately from the semiconductor substrate 12 on the semiconductor substrate 12 . In this case, a semiconductor layer having a crystal structure different from that of the semiconductor substrate 12 (eg, an amorphous semiconductor layer, A microcrystalline semiconductor layer or a polycrystalline semiconductor layer, for example, an amorphous silicon layer, a microcrystalline silicon layer, or a polycrystalline silicon layer).

Among the first and second conductive regions 20 and 30 , one region having a different conductivity type from that of the semiconductor substrate 12 constitutes at least a portion of the emitter region. Among the first and second conductivity type regions 20 and 30 , another one having the same conductivity type as the base region 14 constitutes at least a part of the surface field region. For example, in this embodiment, the semiconductor substrate 12 and the second conductive region 30 may have n-type second conductivity, and the first conductive region 20 may have p-type. Then, the semiconductor substrate 12 and the first conductive region 20 form a pn junction. When light is irradiated to such a pn junction, electrons generated by the photoelectric effect move toward the rear surface of the semiconductor substrate 12 and are collected by the second electrode 44, and holes move toward the front surface of the semiconductor substrate 12 to be removed. 1 is collected by the electrode 42. As a result, electrical energy is generated. Then, holes moving at a slower speed than electrons may move to the front surface of the semiconductor substrate 12 instead of the rear surface, so that efficiency may be improved. However, the present invention is not limited thereto, and it is also possible that the semiconductor substrate 14 and the second conductivity type region 30 have p type and the first conductivity type region 20 has n type. In addition, the semiconductor substrate 12 may have the same conductivity type as the second conductivity type region 30 and an opposite conductivity type to that of the first conductivity type region 20 .

In this case, as the first or second conductivity-type dopant, various materials capable of exhibiting n-type or p-type may be used. As the p-type dopant, a Group 3 element such as boron (B), aluminum (Al), gallium (Ga), or indium (In) may be used. In the case of the n-type, a group 5 element such as phosphorus (P), arsenic (As), bismuth (Bi), and antimony (Sb) may be used. For example, the p-type dopant may be boron (B) and the n-type dopant may be phosphorus (P).

And, on the entire surface of the semiconductor substrate 12 (more precisely, on the first conductive region 20 formed on the entire surface of the semiconductor substrate 12), a first passivation film 22 that is a first insulating film and/or an antireflection film (24) can be positioned (eg, contacted). And, on the back surface of the semiconductor substrate 12 (more precisely, on the second conductive region 30 formed on the back surface of the semiconductor substrate 12), a second passivation film 32, which is a second insulating film, is positioned (for example, , contact). The first passivation layer 22, the anti-reflection layer 24, and the second passivation layer 32 may be formed of various insulating materials. For example, the first passivation film 22, the antireflection film 24 or the second passivation film 32 may include a silicon nitride film, a silicon nitride film containing hydrogen, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, a silicon carbide film, MgF2, Any single layer selected from the group consisting of ZnS, TiO 2 and CeO 2 may have a multi-layer structure in which two or more layers are combined. However, the present invention is not limited thereto.

The first electrode 42 is electrically connected to the first conductive region 20 through an opening penetrating the first insulating film, and the second electrode 44 is a second conductive type through an opening penetrating the second insulating film. It is electrically connected to region 30 . The first and second electrodes 42 and 44 are made of various conductive materials (eg, metal) and may have various shapes.

As described above, the first piece cell and the second piece cell used in one embodiment may be formed by dividing a mother cell into a plurality of pieces, which will be described with reference to FIG. 5 . 7 is a schematic diagram showing how fragment cells are formed from a mother cell.

The mother cell 1 is preferably a solar cell having an approximately octagonal shape with chamfers 1a formed at each corner. The mother cell 1 has a substantially square shape in which the long side in the first direction (x-axis direction in the drawing) and the long side in the second direction (y-axis direction in the drawing) are substantially the same, but each corner has a chamfer 1a By being formed, it has an octagonal shape as a whole.

The mother cell 1 is manufactured from a circular ingot (single crystal basis), and is made into an approximately octagonal shape with chamfers 1a at the corners in order to have a maximum area.

The parent cell 1 having such a shape is divided into a plurality of pieces according to the scribing lines SL arranged to have a regular interval with those adjacent to each other in the first direction (x-axis direction in the drawing). The scribing line SL extends from one long side toward the other long side parallel to the long side in the first or second direction. In the drawing, it is exemplified that the scribing lines SL are arranged parallel to the long side of the second direction (y-axis direction in the drawing).

The parent cell 1 is divided into a plurality of pieces based on the scribing line SL to form a piece cell. The number of fragment cells to be divided is determined in consideration of variables, and considering these process conditions, the mother cell 1 may be divided into 2 to 12 cells. In the drawing, it is exemplified that the mother cell 1 is divided into six cells according to the cell unit 33 . When the mother cell (1) is divided into two, it is possible to minimize the damage applied to the mother cell (for example, thermal shock by laser, etc.) compared to when the mother cell is divided into two, and when the number is larger than 12, the size of the fragmented cell is small. It is difficult to connect fragment cells in a shingled manner.

The mother cell 1 can be evenly divided by the scribing lines SL, and the mother cell 1 can be largely divided into first to third regions A1 to A3. The first area A1 is between the first scribing line SL1 on one long side, and the second area A2 is the area between the second scribing line SL2 on the other long side. and the second regions A1 and A2 are regions including the chamfer 1a, and the first and second regions A1 and A2 are engraved by the first and second scribing lines SL1 and SL2. When divided into cells, the first area A1 forms the hexagonal second piece cells 12 due to chamfers formed at corners. Also, the third area A3 is an area between the first scribing line SL1 and the second scribing line SL2, and the second area A2 has a rectangular shape. Accordingly, the third area A3 is divided into a plurality of cells by the third scribing line SL3 dividing the third area A3, and the rectangular first piece cells 11 are formed.

On the other hand, as described above, the string ST of one example is composed of a cell unit 33 as a minimum unit. In one example, the cell unit 33 includes two first piece cells 11 and one second piece cell 12. Therefore, if the mother cell 1 is divided into 6 pieces of cells in this way, one mother cell 1 can constitute two cell units 33, and all the pieces of cells divided in the mother cell 1 (this In the embodiment, two first piece cells and four second piece cells) can be used to form a string.

The above description describes an example in which the mother cell 1 has a chamfer 1a and is divided into two types of first piece cells 11 and second piece cells 12 having different shapes, but the mother cell 1 ) may be divided into fragment cells having the same shape. For example, the mother cell 1 may be divided into two piece cells along a scribing line passing through the center of the mother cell 1, or the mother cell 1 may have a rectangular shape without a chamfer 1a. In this case, this parent cell may be divided only into quadrangular shapes having long sides and short sides.

Hereinafter, connection relationships between strings of solar cell modules will be described with reference to FIGS. 8 to 12 . FIG. 8 shows an overall front view of an exemplary solar cell module, FIG. 9 shows a rear view in which two cell blocks adjacent to each other are connected in parallel around a hidden tap, and FIG. 11 and 12 are cross-sectional views, each showing a state in which two adjacent strings are connected in parallel by an edge connector and an interconnector at the beginning and end of the string.

Referring to these drawings, the solar cell module 100 of this embodiment is configured to include a plurality of strings ST1 to ST6 connected in parallel. As described above, each of the strings ST1 to ST6 constitutes a cell block 31 in which the cell unit 33 is the minimum unit, and the cell blocks 31 are adjacent to each other (in the y-axis direction of the drawing). same as the string direction) and the hidden tap 51 connected in series. Preferably, in each string ST1 to ST6, seven cell units 331 to 337 constitute one cell block 31a, 31b, and 31c, and three cell blocks 31a to 31c are gathered to form one Strings can be constructed.

In the cell unit 33, each piece cell is electrically connected in series with its neighbor while being connected to its neighbor in the second direction (y-axis direction in the drawing) in a shingled connection method (the piece cell is divided into the rear and front surfaces, and the first electrode and the second electrode are disposed, and the first electrode and the second electrode of the two adjacent piece cells are connected by a shingled connection), and the cell blocks are electrically connected in series by the hidden tap 51, In each string (ST1 to ST6), all of the piece cells are connected in series.

The hidden tap 51 may include a first part 511 and a plurality of second parts 513 protruding from the first part 511 .

The first portion 511 has a thin strip shape and is formed long in a first direction (x-axis direction in the drawing). The second portion 513 has a larger width than the first portion 511 and protrudes from the first portion 511 in the second direction (y-axis direction in the drawing). Preferably, the second portion 513 is composed of a plurality, but is not limited thereto, and the width or number may be determined in consideration of contact resistance, connectivity with an interconnector, and the like.

The first part 511 includes a part of the second piece cell 12E disposed at the end of the first cell block 31a and the second cell among the two cell blocks 31a and 31b neighboring in the second direction. A part of the first piece cell 11F disposed at the beginning of the block 32 is disposed so as not to be seen from the front in the overlapping portion OP formed by overlapping each other.

More precisely, the first part 511 disposed in the overlapping portion OP may be a pad provided on one front side of the second sliced cell 12E (the side close to the hidden tap) and the other rear side of the first sliced cell 11F, respectively. Positioned to be overlapped to face the first bus bar electrode, they may be physically and electrically connected by the conductive member CA. As a result, two neighboring cell blocks 31a and 31b can be connected in series.

The second portion 513 protrudes from the first portion 511 in the second direction (or the length direction of the string) to expose a portion of the hidden tap 51 outside the overlapping portion OP. In addition, an insulating member IM may be further positioned between the rear surfaces of the first piece cells 11F of the second portion 513 of the hidden tap 51 to electrically insulate the two. For example, the insulating member IM may be an insulating resin, but various materials may be used without particular limitation as long as they can electrically insulate between the two.

In each of the strings ST1 to ST6, the string may further include edge connectors 53 disposed at the beginning and end of the string. For example, first slice cells 11S may be disposed at the beginning of each string ST1 to ST6, and second slice cells 12E may be disposed at the end.

The edge connector 53 includes a line portion 531 extending in a first direction (x-axis direction in the drawing) and a protrusion 533 protruding in a second direction (y-axis direction in the drawing) from the line portion 531. It may be configured to include a shape and may be substantially the same as a hidden tap. Here, the edge connector 53 disposed on the first piece cell 11S is attached to one of the front and rear surfaces of the first piece cell 11S, and the edge connector disposed on the second piece cell 12E ( 53) may be attached to the opposite side of the second piece cell 12E.

Preferably, in the first piece cell 11S and the second piece cell 12E, the line portion 531 of the edge connector 53 is interviewed with a pad or a first (or second) bus bar electrode (not shown). and may be electrically and physically connected by the conductive member CA.

In this way, the hidden tap 51 and the edge connector 53 disposed in each string may be electrically connected by first and second interconnectors 61 and 63, respectively.

The first interconnector 61 connects the hidden tap 51 connecting the cell blocks in each string ST1 to ST6 in the middle of the string to the adjacent string in parallel. The first interconnector 61 has a line shape, is arranged to cross the first string ST1 to the last sixth string ST6, and has a hidden tap ( 51), more precisely, it is physically bonded to the second part 513 of the hidden tap 51. Physical bonding is, in a preferred form, soldering through solder between parent materials, but limited to this, it may also be bonded by the conductive member CA.

The second inter connector 63 is disposed at the end of the string parallel to the first inter connector 61, and is physically bonded to the edge connector 53 connected to the end of the string. Since the second interconnector 63 has substantially the same physical configuration as that of the first interconnector 63, a detailed description thereof will be omitted. More precisely, the second interconnector 63 may be arranged to cross the protrusion 533 of the edge connector 53 .

With this configuration, each string (ST1 to ST6) can be connected in series and connected in parallel for each cell block of each string. According to this configuration, even if part of the string is shut down, normal operation is possible for part of the string, more precisely, for each cell block, because a detour path is formed.

Hereinafter, the circuit configuration of the solar cell module according to the present embodiment will be described with reference to FIGS. 13 and 14 . FIG. 13 is a diagram showing a physical configuration of a solar cell module according to the present embodiment, and FIG. 14 is a diagram showing an equivalent circuit configuration of FIG. 13 .

Referring to this figure, the solar cell module 100 of this embodiment is disposed on the rear side of the string and includes a junction box (JB) in which a bypass diode (BD) is built. In one example, the bypass diode (BD) is configured to include first to third bypass diodes BD1 to BD3 connected in series.

As shown in the drawing, each string ST1 to ST6 is configured to include first to third cell blocks 31a to 31c, and the first cell block 31a disposed in each string ST1 to ST6 The through third cell blocks 32b to 31c are configured to be connected in parallel by the hidden tap 51, the edge connector 53, and the first interconnector 61 and the second interconnectors 51 and 53.

In addition, the solar cell module 100 of this embodiment is configured to further include bussing connectors 65a to 65d disposed on the rear surface of the module. The bussing connectors 65a to 65d connect the interconnectors 51 and 53 and the bypass diodes BD1 to B3 so that even if a reverse bias is applied to a part of the string, the reverse bias is bypassed to the bypass diode so that the string is turned off. (off) to prevent

The bussing connectors 65a to 65d may be formed to have a long line shape in the second direction (y-axis direction in the drawing), and may be disposed parallel to other bussing connectors. In the drawing, the junction box JB is disposed close to one side of the string and far from the other side, so that the first busing connector 65a is the shortest and the fourth busing connector 65d is the longest. However, the junction box JB ) can be changed according to the selection, and the length of the busing connector can also be adjusted accordingly.

The first bussing connector 65a electrically connects the positive polarity of the first bypass diode BD1 and the second interconnector 53 disposed at the front end of the string, and connects the first through the first node N1. The bussing connector 65a may be connected to the second interconnector 53b. The first bussing connector 65a may be soldered to the second interconnector 53 or connected by a conductive member, but it is preferably soldered for convenient operation.

The second busing connector 65b is a second node N2 commonly connected to the first cell block 31a and the second cell block 31b, that is, between the first cell block 31a and the second cell block 31b. One end is bonded to the first interconnector 51a disposed on and the other end is commonly connected to the negative polarity of the first bypass diode B1 and the negative polarity of the second bypass diode, thereby forming the first cell block 31a. forms the bypass path of

The third bussing connector 65c includes the third node N3 commonly connected to the second cell block 31b and the third cell block 31c, the negative electrode of the second bypass diode BD2 and the third bypass diode 65c. A bypass path of the second cell block 31b is formed by connecting the positive polarities of the BD3, and the fourth busing connector 65d is connected to the negative electrode of the third cell block 31c in common with the fourth node N4. and the negative polarity of the third bypass diode BD3 are connected to form bypass paths of the third cell block 31c, respectively.

In this embodiment, the hidden tap, the interconnector, and the bussing connector are a core layer made of metal, a ribbon or insulating substrate made of a solder material (eg, Sn, Pb) coating the core layer and distributed inside the insulating substrate. It may be composed of one of conductive films made of conductive particles, but is not limited thereto, and various known ones may be used.

With this connection structure, the solar cell modules of the present invention can be connected in series for each string and connected in parallel for each cell block. Accordingly, even if a reverse bias occurs in one part of the string, the reverse bias bypasses the cell block through the bypass path, so that the string itself can be prevented from being turned off by the reverse bias.

Furthermore, since the solar cell module of the present invention has hidden taps installed in units of cell blocks for each string, it is possible to easily connect a part of a string connected in a shingled manner, that is, a cell block, to a cell block of another adjacent string.

Meanwhile, in addition to the hidden tap 51 described above, the shape of the hidden tap 51 may be variously changed. A schematic configuration of a solar cell module connected by hidden taps 51 according to another example is shown in FIGS. 15 to 17 . 15 to 17, the cell block 31 is shown in a rectangular shape to simplify the drawings.

In FIG. 15 , the hidden tap 110 may have a rectangular shape having a long side and a short side, and a portion disposed on the overlapping portion OP constitutes the first portion 110a of the hidden tap, and the overlapping portion OP A portion exposed to the outside constitutes the second portion 110b of the hidden tap.

The hidden tap 110 having such a shape can increase the area of the part connected to the first interconnector 61, that is, the second part 110b, compared to the hidden tap 51 described above. Contact resistance between the tab 110 and the first interconnector 61 is reduced.

In FIG. 16 , the hidden tap 210 is disposed in the overlapping portion OP and partially protrudes from one end of the first portion 210a of the first portion 210a exposed outside the overlapping portion, and is disposed on an adjacent string. The second portion 210b disposed to partially overlap a portion of the hidden tap 210 may be included.

The head tap 210 in this example is configured so that some of the hidden taps disposed adjacent to each other in the first direction (x-axis direction in the drawing) partially overlap, so that they are directly connected without being connected by the interconnector 61 as in the above-described examples. It is different from the hidden taps of the above-described example in that

Optionally, the hidden tap 210 of this example may be additionally connected by an interconnector 61, in which case the interconnector 61 is exposed to the outside among the first part 210a of the hidden tap 210. It can be joined to the part that has been made.

In FIG. 17 , the hidden tap 310 is formed to have a long line shape in the first direction. Some of the hidden taps 310 are positioned at the overlapping portion OP to form the first part 310a, and a part extending between two adjacent strings forms the second part 310b of the hidden tap 310. Between two adjacent strings, the second part 310b of the hidden tap 310 overlaps with the second part 310b of the other hidden tap 310 disposed in the neighboring string and can be electrically and physically connected, and thus The cell blocks 31 of two neighboring strings can be connected only by the connection of the hidden tap 310 without the aid of an interconnector.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also made according to the present invention. falls within the scope of the rights of

Claims (11)

A string in which a plurality of piece cells are connected to have an overlapping portion;
a hidden tap including a first portion disposed in the overlapping portion and a second portion exposed from the first portion to the outside of the overlapping portion;
an insulating member disposed between the second part of the hidden tap and the rear surface of the piece cell; and
Including a line-shaped interconnector formed elongated in one direction,
The string has the hidden tap and includes a plurality of strings arranged in parallel with other neighboring strings,
a second part of the hidden tap of the plurality of strings is connected in common;
The first part of the hidden tap is formed long in a thin strip shape along the width direction of the string,
A plurality of second parts of the hidden tap protrude from the first part along the length direction of the string, a plurality of second parts are spaced apart from each other, and each of the plurality of second parts is having a width greater than the width of one part,
The interconnector is disposed to cross the plurality of strings, and is connected to the second part in each of the plurality of strings. delete delete delete delete According to claim 1,
The solar cell module of claim 1 , wherein the hidden tab and the interconnector are composed of one of a ribbon composed of a conductor and solder covering the conductor, or a conductive film composed of an insulating substrate and conductive particles distributed inside the insulating substrate. delete According to claim 1,
The string is a solar cell module in which a plurality of cell units are repeatedly arranged, including n first piece cells having long and short sides and m second piece cells having chamfers at portions of corners. According to claim 8,
The cell unit has a hexagonal shape including two first piece cells and one second piece cell. According to claim 8,
The cell unit has an octagonal shape including four first piece cells and two second piece cells. According to claim 1,
The solar cell module of claim 1 , wherein the string is divided into at least two or more cell blocks obtained by dividing the plurality of piece cells into the same number, and the hidden tap is disposed between each cell block.

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