KR20210138537A - Solar cell module - Google Patents

Abstract

The present invention relates to a solar cell module. According to the present invention, the solar cell module comprises: a first solar cell and a second solar cell including a plurality of first electrodes and a plurality of second electrodes formed to be spaced apart from each other on a rear surface of a semiconductor substrate, a first conductive wire connected to the plurality of first electrodes, and a second conductive wire connected to the plurality of second electrodes; and an interconnector electrically connecting the first conductive wire of the first solar cell and the second conductive wire of the second solar cell. The area of a first connection region where the interconnector is connected to the first conductive wire of the first solar cell is different from the area of a second connection region where the interconnector is connected to the second conductive wire of the second solar cell.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module.

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

In particular, in order to increase the efficiency of the solar cell, research and development on a back-electrode type solar cell in which an n-electrode and a p-electrode are formed only on the back surface of the silicon substrate without forming an electrode on the light-receiving surface of the silicon substrate are being conducted. A modular technology for electrically connecting a plurality of such back-electrode type solar cells is also in progress.

A method of electrically connecting a plurality of solar cells with a metal interconnector and a method of electrically connecting a plurality of solar cells using a wiring board on which wiring is formed are representative of the module and technology.

An object of the present invention is to provide a solar cell module.

The solar cell module according to the present invention includes a plurality of first electrodes and a plurality of second electrodes formed to be spaced apart from each other on a rear surface of a semiconductor substrate, a first conductive wire connected to the plurality of first electrodes, and a plurality of second electrodes connected to each other a first solar cell and a second solar cell including a second conductive wiring; and an interconnector electrically connecting the first conductive wire of the first solar cell and the second conductive wire of the second solar cell, wherein the interconnector connects to the first conductive wire of the first solar cell. The area of the region is different from the area of the second connection region where the interconnector connects to the second conductive wiring of the second solar cell.

Here, the interconnector and the first and second conductive wirings of the first and second solar cells overlap each other, and in the region where the interconnector and the first conductive wiring overlap, the first connection regions are spaced apart from each other to form a plurality of interconnectors, A plurality of second connection regions may be formed to be spaced apart from each other in a region where the and second conductive wirings overlap. In this case, the total area of the plurality of first connection areas may be different from the total area of the plurality of second connection areas.

In addition, the interconnector and the first and second conductive wirings of the first and second solar cells may be connected to each other by an interconnector adhesive made of a conductive material. An area of the first application region of the adhesive may be different from an area of the second application region of the interconnect adhesive in a region where the interconnector and the second conductive wiring overlap.

For example, in the region where the interconnector and the first conductive wiring overlap, the first application region is formed in plurality and spaced apart from each other in the second direction intersecting the first direction, and in the region where the interconnector and the second conductive wiring overlap A plurality of second application regions may be formed to be spaced apart from each other in the second direction, and even in this case, the total area of the plurality of first application regions may be different from the total area of the plurality of second application regions.

In addition, the interconnector is formed to be elongated in a second direction intersecting the first direction, and an area of any one of the plurality of first connection regions is located in a portion symmetrical to each other with respect to the center line of the interconnector parallel to the second direction. An area of any one of the plurality of second connection areas may be different.

Further, the interconnector overlaps the first conductive wiring of the first solar cell and the second conductive wiring of the second solar cell, and the first overlapping area between the interconnector and the first conductive wiring is between the interconnector and the second conductive wiring. may be different from the second overlapping area of .

For example, the first solar cell and the second solar cell are arranged in a first direction by interconnector connection, and a first overlapping width in a first direction in which the interconnector and the first conductive wiring overlap is a width of the interconnector and the second solar cell. The width of the second overlap in the first direction overlapped between the conductive lines may be different. In this case, the length at which the interconnector and the first conductive line overlap in the second direction intersecting the first direction may be the same as the length at which the interconnector and the second conductive line overlap in the second direction.

In addition, in each of the first and second solar cells, the first conductive wiring includes a first connection part connected to the first electrode, a first pad part having one end connected to an end of the first connection part, and the other end being connected to an interconnector, , the second conductive wiring may include a second connecting portion connected to the second electrode, and a second pad portion having one end connected to an end of the second connecting portion and the other end connected to an interconnector.

Further, in each of the first and second solar cells, each of the first and second conductive wirings is formed of a plurality of wires, and the first conductive wirings provided with the plurality of wires in the first solar cell are connected to the interconnector. The sum of the areas of the first connection region may be different from the sum of the areas of the plurality of second connection regions through which the second conductive wiring provided as a plurality of wires in the second solar cell is connected to the interconnector.

In this case, in each of the first and second solar cells, the connection position or connection area of at least one of the plurality of first connection regions connected to the interconnector may be different from the connection position or connection area of the other first connection regions. have.

In addition, in each of the first and second solar cells, the connection position or connection area of at least one of the plurality of second connection regions connected to the interconnector may be different from the connection position or connection area of the other second connection regions. have.

As described above, in the solar cell module according to the present invention, the area of the first connection area in which the interconnector connects to the first solar cell and the area of the second connection area in which the interconnector connects to the second solar cell are different from each other. It is possible to minimize the thermal expansion stress that can be received.

1 is a plan view of a first embodiment of a solar cell module according to the present invention.
FIG. 2A is a view for explaining an example of a cross section taken along line 2-2 shown in FIG. 1 .
FIG. 2B is a view for explaining another example of a cross section taken along line 2-2 shown in FIG. 1 .
3 is a plan view of a second embodiment of a solar cell module according to the present invention.
FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3 .
5 is a view for explaining a third embodiment of the solar cell module according to the present invention.
6 is an example of a partial perspective view of a solar cell according to an example of the present invention.
7 is a cross-sectional view illustrating the solar cell shown in FIG. 6 taken along line 7-7.
FIG. 8 is a diagram for explaining an example of electrode patterns of the semiconductor substrate 110 and the insulating member 200 to be individually connected in the solar cell described with reference to FIGS. 6 and 7 .
9 is a view for explaining a state in which the semiconductor substrate 110 and the insulating member 200 shown in FIG. 8 are connected to each other.
FIG. 10A is a cross-sectional view of line 10a-10a in FIG. 9 .
FIG. 10b is a cross-sectional view of line 10b-10b in FIG. 9 .
FIG. 10c is a cross-sectional view of line 10c-10c in FIG. 9 .
11 to 15 are views for explaining a solar cell module in which first and second conductive wirings are formed of a plurality of wires.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in various various forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are given to similar parts throughout the specification.

Hereinafter, the front surface may be one surface of the semiconductor substrate or the front glass substrate on which direct light is incident, and the rear surface may refer to a semiconductor substrate and a front glass substrate to which direct light is not incident or reflected light other than direct light is incident. may be the opposite side of one side of

Hereinafter, a solar cell module according to the present invention and a solar cell applied thereto will be described.

1 is a plan view of a first embodiment of a solar cell module according to the present invention, FIG. 2A is a diagram for explaining an example of a cross section taken along line 2-2 shown in FIG. 1, FIG. 2B is FIG. It is a diagram for explaining another example of a cross-section taken along line 2-2 shown in FIG.

1 to 2A , an example of a solar cell module according to the present invention includes a first solar cell CE1 , a second solar cell CE2 , and an interconnector IC.

1 to 2A , a case in which the connection areas are different from each other in a state where the overlapping areas between the interconnector IC and the first and second solar cells CE1 and CE2 are the same will be described as an example.

Here, each of the first and second solar cells CE1 and CE2 includes a semiconductor substrate 110 and a plurality of first electrodes C141 and a plurality of second electrodes C142 formed to be spaced apart from each other on the rear surface of the semiconductor substrate 110 , respectively. ), a first conductive wire P141 connected to the plurality of first electrodes C141, and a second conductive wire P142 connected to the plurality of second electrodes C142, and in addition, FIGS. 1 to 2B . Although not shown in FIG. 6 , an insulating member (not shown) may be further included on the rear surfaces of the first and second conductive wires P141 and P142 as shown in FIG. 6 or less.

A solar cell applied to each of the first and second solar cells CE1 and CE2 will be described in more detail below with reference to FIG. 6 .

The first and second solar cells CE1 and CE2 may be arranged in series connected in the first direction x by the interconnector IC.

Here, the interconnector IC functions to electrically connect the first solar cell CE1 and the second solar cell CE2 in series to each other, and for example, as shown in FIG. 1 , the first solar cell ( The first conductive line P141 of CE1 and the second conductive line P142 of the second solar cell CE2 may be electrically connected to each other. However, on the contrary, the second conductive wiring P142 of the first solar cell CE1 and the first conductive wiring P141 of the second solar cell CE2 may be electrically connected to each other.

Such an interconnector (IC) may include a conductive material, for example, may include copper (Cu), and may be formed of tin (Sn) on the surface to prevent oxidation of copper (Cu). An anti-oxidation layer may be formed.

Here, in the solar cell module according to the present invention, as shown in FIG. 2A , the interconnector IC includes the first conductive line P141 of the first solar cell CE1 and the second conductive line P141 of the second solar cell CE2 . It may be directly connected to the conductive wiring P142 without a separate interconnector adhesive ICA.

For example, the interconnector IC may be directly connected to the first and second solar cells CE1 and CE2 through a local selective heat treatment method such as laser or induction, or a method such as sonic welding.

At this time, as shown in FIG. 1 , a region in which the interconnector IC is connected to the first conductive wiring P141 of the first solar cell CE1 is connected to the first connection region CS1 and the interconnector IC is If the region connected to the second conductive line P142 of the second solar cell CE2 is referred to as a second connection region CS2 , in the present invention, the area of the first connection region CS1 is the second connection region CS2 . may be different from the area of

More specifically, as shown in FIG. 1 , the interconnector IC may overlap each of the first and second conductive wires P141 and P142 of the first and second solar cells CE1 and CE2 . For example, the first overlapping width OS1 overlapping the interconnector IC and the first conductive line P141 of the first solar cell CE1 in the first direction x is the interconnector IC and the second conductive line P141 . It may be the same as the second overlapping width OS2 overlapping the second conductive line P142 of the solar cell CE2 in the first direction (x). However, it is also possible that the overlapping widths are different from each other as shown.

At this time, in the region where the interconnector IC and the first conductive wiring P141 overlap each other, the first connection region CS1 is spaced apart from each other in the second direction y to form a plurality of CS1a, CS1b, and CS1c. In the region where the interconnector IC and the second conductive wiring P142 overlap each other, the second connection region CS2 is also spaced apart from each other in the second direction y to a plurality of CS2a, CS2b, and CS2c. can be formed with

In order to further relieve the thermal expansion stress applied to the interconnector IC in the plurality of first connection regions CS1 formed between the interconnector IC and the first solar cell CE1 as described above, the area of the CS1a connection region is The area of the immediately adjacent CS1b connection region may be different, and the area of the CS1b connection region may be different from the area of the immediately adjacent CS1c connection region.

In addition, even in the plurality of second connection regions CS2 formed between the interconnector IC and the second solar cell CE2 , the areas of the CS2a connection region and the CS2b connection region immediately adjacent to each other may be different from each other. The area of the immediately adjacent CS2b connection region and the area of the CS2c connection region may be different from each other.

In addition, the total area of the plurality of first connection areas CS1 may be different from the total area of the plurality of second connection areas CS2 .

In addition, at this time, the interconnector IC may be elongated in the second direction y intersecting the first direction x, and any one of the plurality of first connection areas CS1 (eg, CS1a) The area of is different from the area of any one (eg, CS2a) of the plurality of second connection regions CS2 positioned at portions symmetrical to each other with respect to the center line of the interconnector IC parallel to the second direction y can

Accordingly, as illustrated in FIG. 2A , the width WCS1a of the CS1a connection region in the first direction (x) may be different from the width WCS2a of the CS2a connection region in the first direction (x). For example, the width WCS1a of the CS1a connection region may be greater than the width WCS2a of the CS2a connection region.

In FIG. 2A, a case in which the interconnector IC is directly connected to the first and second conductive wirings P141 and P142 of the first and second solar cells CE1 and CE2 has been described as an example. IC) is, as shown in FIG. 2B, the interconnector IC and the first and second conductive wires P141 and P142 of the first and second solar cells CE1 and CE2 are electrically conductive material interconnector adhesive (ICA) can be connected to each other by

In this case, the interconnect adhesive ICA may be a solder paste, a conductive paste including metal particles in an insulating resin, a conductive film, or the like. In addition, carbon nano tube (CNT), conductive particles containing carbon, wire, needle, etc. may be used.

Even in this case, in the region OS1 where the interconnector IC and the first conductive wiring P141 overlap, the area of the first application region CS1 of the interconnector adhesive ICA is equal to that of the interconnector IC and the second conductive wiring P141. The area OS2 where the two conductive wirings P142 overlap may be different from the area of the second application area CS2 of the interconnector adhesive ICA.

Therefore, even when the interconnector IC is connected to the first and second conductive wires P141 and P142 of the first and second solar cells CE1 and CE2 through the interconnect adhesive ICA, the first and second connection regions (CS1, CS2) may be the same as in FIG. 1 .

Accordingly, in the region OS1 where the interconnector IC and the first conductive wiring P141 overlap, the first application region CS1 is spaced apart from each other in the second direction y intersecting the first direction x. In the region OS2 where the interconnector IC and the second conductive wiring P142 overlap each other, the second application region CS1 may be formed in plurality and spaced apart from each other in the second direction y. , even in this case, the total area of the plurality of first application areas CS1 may be different from the total area of the plurality of second application areas CS1 .

As described above, in the solar cell module according to the present invention, the first and second connection regions CS1 and CS2 are formed to have different areas from each other, and the first and second connection regions CS1 and CS2 have a plurality of each other. By being spaced apart and dispersed, the thermal expansion stress applied to the interconnector IC when the interconnector IC is connected to each solar cell can be further alleviated.

In addition, as shown in FIG. 1 , each of the plurality of first and second connection regions CS1 and CS2 arranged in the second direction y of the interconnector IC is formed to have different areas, so that the interconnector IC is formed differently. The thermal expansion stress applied to (IC) can be further alleviated.

In addition, since it is not necessary to align the areas of the first connection region CS1 and the second connection region CS2 to be equal to each other, the degree of design freedom is further improved and the interconnector (IC) connection process is made easier. can do.

In FIG. 1 , the case where the overlapping widths of the interconnector IC and the first and second conductive wirings P141 and P142 are the same has been described as an example, but the overlapping widths are not necessarily the same.

3 and 4 are diagrams for explaining a second embodiment of the solar cell module according to the present invention.

3 is a plan view of a second embodiment of a solar cell module according to the present invention, and FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3 . Hereinafter, parts different from those described with reference to FIGS. 1 to 2B will be described with reference to FIGS. 3 and 4 .

Here, in FIGS. 3 to 4 , a case in which the connection areas are different from each other in a state where the overlapping areas between the interconnector IC and the first and second solar cells CE1 and CE2 are different from each other will be described as an example.

As shown in FIG. 3 , the first overlapping area OS1 between the interconnector IC and the first conductive line P141 is a second overlapping area between the interconnector IC and the second conductive line P142 . (OS2) may be different.

For example, as shown in FIG. 3 , the first overlapping area OS1 between the interconnector IC and the first conductive wiring P141 is formed between the interconnector IC and the second conductive wiring P142. It may be larger than the second overlapping area OS2 .

For example, the overlapping length in the second direction (y) between the interconnector IC and the first conductive line P141 and the second direction (y) between the interconnector IC and the second conductive line P142 The overlapping lengths may be the same, but as shown in FIG. 4 , the first overlapping width OS1 in the first direction (x) between the interconnector IC and the first conductive wiring P141 is Different from the second overlapping width OS2 in the first direction x between the interconnector IC and the second conductive wiring P142, for example, the first overlapping width OS1 is the second overlapping width OS2 ) can be greater than

For example, the first overlapping width OS1 or the second overlapping width OS2 may be formed in a range of 0.5 mm to 3 mm, but within this range, the first overlapping width OS1 and the second overlapping width (OS1) OS2) may be formed differently.

In addition, here, the first spacing DCI1 between the interconnector IC and the semiconductor substrate 110 included in the first solar cell CE1 is also included in the interconnector IC and the second solar cell CE2 . It may be different from the second separation distance DCI2 between the semiconductor substrates 110 .

In addition, the interconnector IC and the first and second solar cells CE1 and CE2 may be connected to each other by the interconnect adhesive ICA in the entire area overlapping each other. Accordingly, the area of the first connection region CS1 that the interconnector IC connects between the first solar cells CE1 may be the same as the first overlapping area OS1, and the interconnector IC connects the second solar cell CE1 to each other. An area of the second connection region CS2 connected between the solar cells CE2 may be the same as the second overlapping area OS2 . Accordingly, the area of the first connection area CS1 and the area of the second connection area CS2 may also be different.

As described above, in a state where the first overlapping area OS1 and the second overlapping area OS2 are different from each other, a plurality of first and second connection areas CS1 and CS2 may be respectively formed as shown in FIGS. 1 to 2B . . This will be described with reference to FIG. 5 as follows.

5 is a view for explaining a third embodiment of the solar cell module according to the present invention.

In FIG. 5 , a case in which a plurality of connection areas are formed in a state where overlapping areas between the interconnector IC and the first and second solar cells CE1 and CE2 are different from each other will be described.

As shown in FIG. 5 , in the third embodiment according to the present invention, the first and second overlapping areas OS1 and OS2 between the interconnector IC and the first and second solar cells CE1 and CE2 are different from each other. In this state, each of the first and second connection regions CS1 and CS2 may be formed in plurality, wherein the total area of the plurality of first connection regions CS1 is equal to the total area of the plurality of second connection regions CS2 and can be different.

In addition, an area of each of the plurality of first connection areas CS1 in the first overlapping area OS1 may be larger than an area of each of the plurality of second connection areas CS2 in the second overlapping area OS2 .

Hereinafter, an example of a solar cell applied to such a solar cell module will be described in more detail.

6 and 7 are diagrams for explaining an example of a solar cell applied to the solar cell module shown in FIGS. 1 to 5 .

6 is an example of a partial perspective view of a solar cell according to an example of the present invention, FIG. 7 is a cross-sectional view illustrating the solar cell shown in FIG. 6 taken along line 7-7, and FIG. 8 is an example in FIGS. 6 and 7 . It is a diagram for explaining an example of electrode patterns of the semiconductor substrate 110 and the insulating member 200 to be individually connected in the solar cell described above.

Here, FIG. 8A is a diagram for explaining an example of a pattern of the first electrode C141 and the second electrode C142 disposed on the rear surface of the semiconductor substrate 110 , and FIG. 8B is FIG. 8 . A cross-sectional view taken along line 8(b)-8(b) in (a), (c) of FIG. 8 is a first conductive wire P141 and a second conductive wire (P141) disposed on the front surface of the insulating member 200 ( P142) is a diagram for explaining an example of the pattern, and (d) of FIG. 8 is a cross-sectional view taken along the line 8(d)-8(d) in FIG. 8(c).

6 and 7, an example of the solar cell according to the present invention includes a semiconductor substrate 110, an anti-reflection film 130, an emitter unit 121, a back surface field (BSF, 172), It may include a plurality of first electrodes C141 , a plurality of second electrodes C142 , a first conductive line P141 and a second conductive line P142 , and the insulating member 200 .

Here, the anti-reflection film 130 and the rear electric field unit 172 may be omitted, and are located between the anti-reflection film 130 and the semiconductor substrate 110 on which light is incident, and have the same conductivity as the semiconductor substrate 110 . It is also possible to further include a front electric field part (not shown) that is an impurity part in which the type of impurity is contained at a higher concentration than that of the semiconductor substrate 110 .

Hereinafter, as shown in FIGS. 6 and 7 , the case in which the anti-reflection film 130 and the rear electric field unit 172 are included will be described as an example.

The semiconductor substrate 110 may be a bulk-type semiconductor substrate 110 made of silicon of a first conductivity type, for example, an n-type conductivity type. The semiconductor substrate 110 may be formed by doping a wafer formed of a silicon material with impurities of the first conductivity type.

The upper surface of the semiconductor substrate 110 may be textured to have a textured surface that is an uneven surface. The anti-reflection film 130 is positioned on the incident surface of the semiconductor substrate 110 , and may be formed of one or more layers, and may be formed of a hydrogenated silicon nitride film (SiNx:H) or the like. In addition, it is also possible to further form a front electric field unit on the front surface of the semiconductor substrate 110 .

The emitter parts 121 are spaced apart from each other in the rear surface of the semiconductor substrate 110 facing the front surface, and extend in a direction parallel to each other. There may be a plurality of emitter units 121 , and the plurality of emitter units 121 may have a second conductivity type opposite to the conductivity type of the semiconductor substrate 110 .

The plurality of emitter portions 121 may be formed by containing p-type impurities of a second conductivity type opposite to that of the crystalline silicon semiconductor substrate 110 at a high concentration through a diffusion process.

A plurality of rear electric field units 172 may be located inside the rear surface of the semiconductor substrate 110 , are spaced apart from the plurality of emitter units 121 in a parallel direction, and are formed in the same direction as the plurality of emitter units 121 . stretched out to Accordingly, as shown in FIGS. 6 and 7 , the plurality of emitter units 121 and the plurality of rear electric field units 172 are alternately positioned on the rear surface of the semiconductor substrate 110 .

The plurality of rear electric field units 172 are impurities containing the same conductivity type as that of the semiconductor substrate 110 at a higher concentration than that of the semiconductor substrate 110 , for example, n++ units. The plurality of rear electric field units 172 may be formed by containing impurities (n++) of the same conductivity type as that of the crystalline silicon semiconductor substrate 110 in a high concentration through a diffusion or deposition process.

The plurality of first electrodes C141 are physically and electrically connected to the emitter part 121 , respectively, and extend apart from each other along the emitter part 121 . Accordingly, when the emitter part 121 extends in the first direction (x), the first electrode C141 may also extend in the first direction (x), and the emitter part 121 moves in the second direction (y). , the first electrode C141 may also extend in the second direction y.

In addition, the plurality of second electrodes C142 are physically and electrically connected to the semiconductor substrate 110 through the rear electric field unit 172 , respectively, and extend along the plurality of rear electric field units 172 .

Accordingly, when the rear electric field unit 172 extends in the first direction (x), the second electrode C142 may also extend in the first direction (x), and the rear electric field unit 172 extends in the second direction (x). When extending in y), the second electrode C142 may also extend in the second direction y.

Here, on the rear surface of the semiconductor substrate 110 , the first electrode C141 and the second electrode C142 are physically separated from each other and electrically isolated from each other.

Accordingly, the first electrode C141 formed on the emitter portion 121 collects charges, for example, holes, which have moved toward the emitter portion 121, and the second electrode (C141) formed on the rear electric field portion 172 C142) may collect electric charges, for example, electrons that have moved toward the corresponding rear electric field unit 172 .

The first conductive wiring P141 includes a first connection part PC141 and a first pad part PP141 as shown in FIG. 8 , and as shown in FIGS. 6 and 7 , the first connection part PC141 ) is connected to the plurality of first electrodes C141, and as shown in FIG. 8 , the first pad part PP141 has one end connected to the end of the first connecting part PC141 and the other end connected to the interconnector IC ) can be connected with

Such a first connection part PC141 may be formed in plurality and each may be connected to a plurality of first electrodes C141. Alternatively, it may be formed as a single barrel electrode, and a plurality of first electrodes ( C141) may be connected.

In addition, when a plurality of first connecting portions PC141 are formed, the first connecting portions PC141 may be formed in the same direction as the plurality of first electrodes C141 or may be formed in a cross direction. In this case, the first connection part PC141 may be electrically connected to each other at a portion overlapping the first electrode C141 .

As shown in FIG. 8 , the second conductive line P142 may include a second connection part PC142 and a second pad part PP142. As shown in FIGS. 6 and 7 , the second connection part PC142 is connected to the plurality of second electrodes C142 , and as shown in FIG. 8 , the second pad part PP142 has one end of the second It is connected to one end of the connection unit PC142, and the other end may be connected to the interconnector IC.

As shown, the second connection part PC142 may also be formed in plurality and may be connected to a plurality of second electrodes C142, respectively, as shown in the figure. A plurality of second electrodes C142 may be connected to the .

Here, when a plurality of second connection units PC142 is formed, the second connection units PC142 may be formed in the same direction as the plurality of second electrodes C142 or may be formed in an intersecting direction. In this case, the second connection part PC142 may be electrically connected to each other at a portion overlapping the second electrode C142 .

The material of the first conductive wiring P141 and the second conductive wiring P142 may include at least one of Cu, Au, Ag, and Al.

In addition, as shown in FIG. 7 , the first conductive wire P141 may be electrically connected to the first electrode C141 through an electrode adhesive ECA made of a conductive material, and the second conductive wire P142 is conductive. It may be electrically connected to the second electrode C142 through an electrode adhesive ECA of a material.

The material of the electrode adhesive (ECA) is not particularly limited as long as it is a conductive material, but a conductive material whose melting point is formed at a relatively low temperature of 140° C. to 180° C. is more preferable. However, the present invention is not necessarily limited thereto, and the melting point may vary.

For example, as the electrode adhesive (ECA), a conductive paste in which conductive metal particles are included in an insulating resin may be used, and in addition, a conductive material such as a solder paste or a conductive adhesive film may be used. This can be used.

In addition, an insulating layer IL for preventing a short circuit may be disposed between the above-described first electrode C141 and the second electrode C142 and between the first conductive line P141 and the second conductive line P142 . . The insulating layer IL may include an insulating resin such as epoxy.

In addition, in FIGS. 6 and 7 , the first connection part PC141 of the first electrode C141 and the first conductive wire P141 overlaps each other, and the second electrode C142 and the second conductive wire P142 are connected to each other. Although only the case where the two connecting portions PC142 overlap each other is illustrated, the first electrode C141 and the second connecting portion PC142 may overlap each other, and the second electrode C142 and the first connecting portion PC141 are different. They may overlap each other. In this case, the insulating layer IL for preventing a short circuit may be positioned between the first electrode C141 and the second connection part PC142 and also between the second electrode C142 and the first connection part PC141 .

The insulating member 200 may be disposed on rear surfaces of the first conductive line P141 and the second conductive line P142 .

The material of the insulating member 200 is not particularly limited as long as it is an insulating material, but may preferably have a relatively high melting point. For example, polyimide, epoxy-glass, polyester, BT (bismaleimide triazine) that is heat-resistant to high temperatures. It may be formed by including at least one material among resins.

Such an insulating member 200 may be formed in the form of a flexible film or in the form of a rigid plate without being flexible.

In the solar cell according to the present invention, the first conductive wiring P141 and the second conductive wiring P142 are previously formed on the front surface of the insulating member 200 , and a plurality of first electrodes are formed on the rear surface of the semiconductor substrate 110 . In a state in which C141 and the plurality of second electrodes C142 are previously formed, the insulating member 200 and the semiconductor substrate 110 may be individually connected to each other to form one individual device.

That is, there may be one semiconductor substrate 110 attached to and connected to one insulating member 200 , and such one insulating member 200 and one semiconductor substrate 110 are attached to each other to form one integrated individual. It may be formed as a device to form one solar cell.

More specifically, by a process of attaching one insulating member 200 and one semiconductor substrate 110 to each other to form one integrated individual device, a plurality of Each of the first electrode C141 and the plurality of second electrodes C142 is attached to the first conductive wire P141 and the second conductive wire P142 formed on the front surface of one insulating member 200 to be electrically connected to each other. can

In the solar cell according to the present invention, the thickness T2 of each of the first conductive line P141 and the second conductive line P142 is the thickness T1 of each of the first electrode C141 and the second electrode C142. ) can be greater than

As described above, by making the thickness T2 of each of the first connection part PC141 and the second connection part PC142 greater than the thickness T1 of each of the first electrode C141 and the second electrode C142, the solar cell manufacturing process Time can be further shortened, and thermal expansion stress on the substrate can be further reduced than when the first electrode C141 and the second electrode C142 are directly formed on the back surface of the semiconductor substrate 110 , so that the solar cell Efficiency can be further improved.

The insulating member 200 is formed when the first conductive wire P141 and the second conductive wire P142 are bonded to the first electrode C141 and the second electrode C142 formed on the rear surface of the semiconductor substrate 110 . , it serves to facilitate the process.

That is, the insulating member 200 in which the first conductive wire P141 and the second conductive wire P142 are formed on the rear surface of the semiconductor substrate 110 on which the first electrode C141 and the second electrode C142 are formed through a semiconductor manufacturing process. ), the insulating member 200 may help the alignment process or the connection step more easily when connecting the front surfaces.

Accordingly, the insulating member 200 may be removed after the first and second conductive wires P141 and P142 are respectively connected to the first and second electrodes C141 and C142 by the connection step. Accordingly, the insulating member 200 may be omitted in the final device of the solar cell. Hereinafter, the case in which the insulating member 200 is provided as before will be described as an example.

In the solar cell according to the present invention manufactured with the above structure, the holes collected through the first conductive line P141 and the electrons collected through the second conductive line P142 are converted to the power of the external device through an external circuit device. can be used

So far, the case in which the semiconductor substrate 110 is a crystalline silicon semiconductor substrate 110 and the emitter portion 121 and the rear electric field portion 172 are formed through a diffusion process has been described as an example.

However, unlike this, a heterojunction solar cell in which the emitter part 121 and the rear electric field part 172 formed of an amorphous silicon material are bonded to the crystalline semiconductor substrate 110 or the emitter part 121 is on the front surface of the semiconductor substrate 110 . The present invention can be equally applied to a solar cell having a structure that is located and connected to the first electrode C141 formed on the rear surface of the semiconductor substrate 110 through a plurality of via holes formed in the semiconductor substrate 110 .

A solar cell having such a structure may connect adjacent solar cells to each other by an interconnector (IC), and accordingly, a plurality of solar cells may be connected in series.

Meanwhile, in this structure, the patterns of the first electrode C141 and the second electrode C142 formed on the rear surface of the semiconductor substrate 110 and the first conductive wiring P141 formed on the front surface of the insulating member 200 are formed. ) and the pattern of the second conductive wiring P142 will be described in more detail as follows.

By attaching and connecting the front surface of one insulating member 200 shown in FIGS. 8C and 8D to the rear surface of one semiconductor substrate 110 shown in FIGS. , it is possible to form one integral individual element. That is, the insulating member 200 and the semiconductor substrate 110 may be coupled or attached in a 1:1 ratio.

At this time, as shown in (a) and (b) of FIG. 8 , a plurality of first electrodes C141 and a plurality of second electrodes C142 are spaced apart from each other on the rear surface of the semiconductor substrate 110 in the first direction. (x) may be formed long.

In addition, as shown in (c) and (d) of FIG. 8 , a first conductive wire P141 and a second conductive wire P142 may be formed on the front surface of the insulating member 200 according to the present invention. .

Here, as described above, the first conductive wiring P141 includes the first connection part PC141 and the first pad part PP141, and as shown in FIG. 8C , the first connection part PC141 ) may be formed to be elongated in the first direction (x), the first pad portion PP141 is formed to be elongated in the second direction (y), and one end is connected to the end of the first connection portion PC141, the other end is It may be connected to an interconnector (IC).

In addition, the second conductive wiring P142 also includes the second connection part PC142 and the second pad part PP142, and as shown in FIG. 8C , the second connection part PC142 is the first connection part. It may be spaced apart from (PC141) and formed to be long in the first direction (x), and the second pad part (PP142) is formed to be long in the second direction (y), and one end is connected to the end of the second connection part (PC142). and the other end may be connected to the interconnector (IC).

Here, the first connection part PC141 and the second pad part PP142 may be spaced apart from each other, and the second connection part PC142 and the first pad part PP141 may also be spaced apart from each other.

Accordingly, on the front surface of the insulating member 200 , a first pad part PP141 may be formed at one end of both ends in the first direction x, and a second pad part PP142 may be formed at the other end thereof.

As such, in the solar cell according to the present invention, only one insulating member 200 is coupled to one semiconductor substrate 110 to form one integrated individual device, thereby making the solar cell module manufacturing process easier, Even if the semiconductor substrate 110 included in any one solar cell is damaged or a defect occurs during the solar cell module manufacturing process, only the corresponding solar cell formed as a single integrated individual device can be replaced, and the process yield can be further improved have.

In addition, as described above, the solar cell formed as one integrated individual device can minimize the thermal expansion stress applied to the semiconductor substrate 110 during the manufacturing process.

Here, by making the area of the insulating member 200 equal to or larger than that of the semiconductor substrate 110 , the interconnector IC can be attached to the front surface of the insulating member 200 when the solar cell and the solar cell are connected to each other. sufficient area can be secured. To this end, the area of the insulating member 200 may be larger than the area of the semiconductor substrate 110 .

To this end, the length of the insulating member 200 in the first direction (x) may be longer than the length of the semiconductor substrate 110 in the first direction (x).

The rear surface of the semiconductor substrate 110 and the front surface of the insulating member 200 are attached to each other, so that the first electrode C141 and the first conductive wiring P141 are connected to each other, and the second electrode C142 and the second electrode C142 are connected to each other. Conductive wirings P142 may be connected to each other.

FIG. 9 is a view for explaining a state in which the semiconductor substrate 110 and the insulating member 200 shown in FIG. 8 are connected to each other, and FIG. 10A is a cross-section of the line 10a-10a in FIG. 9 , and FIG. 10B is a cross-section of the line 10b-10b in FIG. 9 , and FIG. 10c is a cross-section of the line 10c-10c in FIG. 9 .

As shown in FIG. 9 , one semiconductor substrate 110 may be completely overlapped with one insulating member 200 to form one solar cell individual device.

For example, as shown in FIG. 10A , the first electrode C141 formed on the rear surface of the semiconductor substrate 110 and the first connection portion PC141 formed on the front surface of the insulating member 200 overlap each other, and the electrode adhesive (ECA) can be electrically connected to each other.

In addition, the second electrode C142 formed on the rear surface of the semiconductor substrate 110 and the second connection portion PC142 formed on the front surface of the insulating member 200 also overlap each other, and may be electrically connected to each other by an electrode adhesive (ECA). have.

In addition, the insulating layer IL may be filled in a space spaced apart from each other between the first electrode C141 and the second electrode C142 , and a spaced space between the first connection part PC141 and the second connection part PC142 . Also, the insulating layer IL may be filled.

In addition, as shown in FIG. 10B , the insulating layer IL may also be filled in the spaced space between the second connection part PC142 and the first pad part PP141 , and as shown in FIG. 10C , the first The insulating layer IL may also be filled in a space spaced apart between the connection part PC141 and the second pad part PP142.

In addition, as shown in FIG. 9 , each of the first pad part PP141 and the second pad part PP142 includes first regions PP141-S1 and PP142-S1 overlapping the semiconductor substrate 110 , and a semiconductor. It may include second regions PP141-S2 and PP142-S2 that do not overlap the substrate 110 .

In this way, the second region PP141-S2 of the first pad part PP141 and the second region PP142-S2 of the second pad part PP142 are provided to secure a space to be connected to the interconnector IC. ) may be connected to an interconnector (IC).

Each of the first pad part PP141 and the second pad part PP142 according to the present invention includes the second regions PP141-S2 and PP142-S2, so that the interconnector IC can be more easily connected, In addition, when the interconnector IC is connected, thermal expansion stress on the semiconductor substrate 110 may be minimized.

In addition, as described above, the interconnector IC may be connected to the first pad part PP141 or the second pad part PP142 to connect the plurality of solar cells.

Until now, the first electrode C141 and the second electrode C142 formed on the semiconductor substrate 110 overlap the first connection portion PC141 and the second connection portion PC142 formed on the insulating member 200 in a parallel direction and are connected. Although described above, the first electrode C141 and the second electrode C142 formed on the semiconductor substrate 110 are the first and second connectors PC141 and PC142 formed on the insulating member 200 differently. ) and can be connected by overlapping in the direction intersecting with it.

In addition, unlike the figure, the first connection part PC141 and the second connection part PC142 are not formed in plurality, but may be formed as a single conductive electrode, and the first connection part PC141 formed of a single conductive electrode has A plurality of first electrodes C141 may be connected to each other, and a plurality of second electrodes C142 may be connected to the second connection part PC142 formed of one conductive electrode.

A case in which only one of the first pad part PP141 and the second pad part PP142 is formed has been described as an example. However, unlike this, the first pad part PP141 and the second pad part PP142 are each formed in plural. It can also be formed into a dog. A plurality of first connection parts PC141 or a plurality of second connection parts PC142 may be connected to each of the first pad part PP141 or the second pad part PP142 formed in plurality.

In addition, although the case in which the insulating member 200 is provided in the solar cell according to the present invention has been illustrated and described as an example in FIGS. 6 to 10C , the insulating member 200 is different from the first and second electrodes C141 and C142. ) and the first and second conductive wirings P141 and P142 may be removed after they are connected to each other. It may be connected to the second conductive line P142.

11 to 15 are diagrams for explaining a solar cell module in which first and second conductive wirings P141 and P142 are formed of a plurality of wires.

In the following FIGS. 11 to 15 , detailed descriptions of the same contents as those described in FIGS. 1 to 10C will be omitted, and different points will be mainly described.

11 and 12 are roads for explaining an example of a solar cell applied when the first and second conductive wirings P141 and P142 of the solar cell module according to the present invention are formed of a plurality of wires, and FIG. is a partial perspective view of the solar cell, and FIG. 12 shows patterns of the first and second electrodes C141 and C142 formed on the rear surface of the solar cell shown in FIG. 11 .

13 shows an example in which first and second conductive wirings P141 and P142 formed of a plurality of wires are connected to the rear surface of each solar cell shown in FIGS. 11 and 12 through an interconnector IC, and FIG. 14 FIG. 13 is a diagram for explaining a difference in area of a connection region between the first and second conductive wirings P141 and P142 and the interconnector IC in FIG. 13 .

In addition, FIG. 15 is a view for explaining a connection region and a connection position between a plurality of wires provided in the first and second conductive wirings P141 and P142 and the interconnector.

11 , a solar cell applicable to a solar cell module according to an example of the present invention includes an anti-reflection film 130 , a semiconductor substrate 110 , an emitter unit 121 , a rear electric field unit 172 , and a plurality of may include first and second electrodes C141 and C142 of

In addition, as shown in FIG. 12 , the plurality of first and second electrodes C141 and C142 may be alternately formed to extend long in the first direction (x). Here, the description of the anti-reflection film 130 , the semiconductor substrate 110 , the emitter unit 121 , the rear electric field unit 172 , and the plurality of first and second electrodes C141 and C142 is shown in FIGS. 6 to 10C . It may be the same as described.

The first and second conductive wirings P141 and P142 may be provided in the form of a plurality of wires, as shown in FIG. 13 , differently from those described with reference to FIGS. 6 to 10C .

Here, each of the first and second conductive wires P141 and P142 provided in the form of a plurality of wires is in the longitudinal direction of the first and second electrodes C141 and C142 formed on the rear surface of the solar cell as shown in FIG. 13 . It may be formed to be elongated in the second direction (y), which is a direction intersecting with the . However, the length direction of each of the first and second conductive wirings P141 and P142 is not necessarily limited thereto.

At this time, each of the plurality of first and second electrodes C141 and C142 included in each of the first and second solar cells CE1 and CE2 is elongated in the first direction x, and the first and second solar cells CE1 , CE2 may be arranged in a line along the second direction y intersecting the first direction x. In addition, each of the first and second conductive wirings P141 and P142 provided in the form of a plurality of wires may be elongated in the second direction y.

Accordingly, the first and second conductive wires P141 and P142 and each of the first and second electrodes C141 and C142 cross each other and are necessary for serial connection of the first and second solar cells CE1 and CE2 among overlapping portions. The parts may be connected to each other or insulated from each other.

In this case, the connection between the first and second conductive wires P141 and P142 and each of the first and second electrodes C141 and C142 may be made by an electrode adhesive (ECA). Here, the material of the electrode adhesive (ECA) may be the same as described with reference to FIGS. 6 to 10C .

In addition, between the first and second conductive wires P141 and P142 and each of the first and second electrodes C141 and C142 may be insulated by the insulating layer IL. Here, the insulating layer IL may be the same as described with reference to FIGS. 6 to 10C in the electrode adhesive ECA.

Here, the first and second conductive wires P141 and P142 provided in each of the first and second solar cells may be connected by a separate interconnector IC, as shown in FIG. 13 .

For example, the first conductive wiring P141 of the first solar cell and the second conductive wiring P142 of the second solar cell are connected with the interconnector IC interposed therebetween by the interconnector IC adhesive ICA. may be electrically connected to each other. Here, the material of the interconnector (IC) adhesive (ICA) may be the same as described with reference to FIGS. 1 to 5 .

At this time, as shown in FIG. 14 , the area of the plurality of first connection regions CS1a to CS1c in which the first conductive wiring P141 provided as a plurality of wires in the first solar cell is connected to the interconnector IC. The sum of may be different from the sum of the areas of the plurality of second connection regions CS2a to CS2c in which the second conductive wiring P142 provided as a plurality of wires in the second solar cell is connected to the interconnector IC.

For example, as shown in FIG. 14 , the sum of the areas of each of the plurality of first connection areas CS1a to CS1c may be greater than the sum of the areas of each of the plurality of second connection areas CS2a to CS2c. However, conversely, the sum of the areas of each of the plurality of second connection regions CS2a to CS2c may be greater than the sum of the areas of each of the plurality of first connection regions CS1a to CS1c.

In addition, a length OS1 in which each of the plurality of first connection regions CS1a to CS1c overlaps with the interconnector IC is a length at which each of the plurality of second connection regions CS2a to CS2c overlaps with the interconnector IC. (OS2) may be different. For example, as shown in FIG. 14 , the overlapping length OS1 of the first connection areas CS1a to CS1c may be greater than the overlapping length OS2 of the second connection areas CS2a to CS2c. However, conversely, the overlapping length OS2 of the second connection regions CS2a to CS2c may be greater than the overlapping length OS1 of the first connection regions CS1a to CS1c.

In this way, by making the area or overlapping length of the first connection regions CS1a to CS1c different from the area or overlapping length of the second connection regions CS2a to CS2c, in the process of connecting a plurality of solar cells in series, a plurality of wires The alignment process of the provided first and second conductive wirings P141 and P142 may be more easily performed.

In addition, the present invention relates to a connection location or connection of at least one of the first connection regions CS1a to CS1c among the plurality of first connection regions CS1a to CS1c connected to the interconnector IC in each of the first and second solar cells. The area may be different from the connection position or connection area of the remaining first connection regions CS1a to CS1c.

In addition, the connection position or the connection area of at least one of the first connection regions CS1a to CS1c among the plurality of second connection regions CS2a to CS2c connected to the interconnector IC in each of the first and second solar cells is the remainder. A connection position or a connection area of the second connection regions CS2a to CS2c may be formed differently.

For example, as shown in FIG. 15A , the respective areas of the plurality of first connection regions CS1a to CS1c (or the second connection regions CS2a to CS2c) may be formed differently from each other.

In addition, as shown in FIG. 15B , the connection position of CS1b (or CS2b) among the plurality of first connection regions CS1a to CS1c (or the second connection regions CS2a to CS2c) is the first conductivity It may be located at D1 from the end of the wiring P141 (or the second conductive wiring P142), and the connection position of CS1a and CS1c (or CS2a and CS2c) is the first conductive wiring P141 (or the second conductive wiring) (P142)] may be located at D2 smaller than D1.

As described above, according to the present invention, the connection area or connection location of the first and second conductive wires P141 and P142 and the interconnector IC are formed differently from each other, thereby facilitating the process of serially connecting the solar cells. .

In addition, although the case in which the first and second conductive wirings P141 and P142 are formed of a plurality of wires has been described as an example in FIGS. 11 to 15 , the first and second conductive wirings P141 and P142 are formed of a plurality of ribbons. The same can be applied even when formed with

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains may make various modifications, changes and substitutions within the scope without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are for explaining, not limiting, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments and the accompanying drawings. . The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (15)

a plurality of first electrodes disposed on the rear surface of the semiconductor substrate and extending in a first direction; a plurality of second electrodes disposed on the rear surface of the semiconductor substrate and spaced apart from the plurality of first electrodes and extending in the first direction; , a first conductive wiring connected to the plurality of first electrodes, insulated from the plurality of second electrodes and extending in a second direction intersecting the first direction, and connected to the plurality of second electrodes and connected to the plurality of second electrodes a first solar cell and a second solar cell insulated from the first electrode and spaced apart from the first conductive line and each including a second conductive line extending in the second direction and connected in the second direction; and
The first solar cell extends in the first direction between the first solar cell and the second solar cell and is spaced apart from the first solar cell and the second solar cell in the second direction. an interconnector electrically connecting the conductive wire and the second conductive wire of the second solar cell;
An overlapping region of the first and second conductive wires and the interconnector does not overlap the first solar cell and the second solar cell and is disposed between the first solar cell and the second solar cell battery module. The method of claim 1,
A second direction length of a region overlapping the first conductive line and the interconnector in the first direction is different from a second direction length of a region overlapping the second conductive line and the interconnector in the first direction battery module. The method of claim 1,
On the interconnector, the first conductive wire and the second conductive wire overlap in the first direction. The method of claim 1,
The first conductive wiring includes a plurality of first conductive wirings spaced apart from each other in the first direction,
The second conductive wiring includes a plurality of second conductive wirings spaced apart from each other in the first direction,
The second direction lengths of the plurality of first conductive wirings and the regions overlapping in the first direction of the interconnector are the second lengths of the plurality of second conductive wirings and the overlapping regions of the interconnector in the first direction. Solar module with different directional lengths. 5. The method of claim 4,
The second direction lengths of the plurality of first conductive wirings and the regions overlapping in the first direction of the interconnector are the second lengths of the plurality of second conductive wirings and the overlapping regions of the interconnector in the first direction. solar module greater than directional lengths 5. The method of claim 4,
The plurality of first electrodes and the plurality of second electrodes are alternately disposed in the second direction,
The plurality of first conductive wires and the plurality of second conductive wires are alternately disposed in the first direction. 5. The method of claim 4,
The total area of the first application regions of the adhesive disposed between the plurality of first conductive wirings and the interconnector is equal to the total area of the second application regions of the adhesive disposed between the plurality of second conductive wirings and the interconnector, and different solar modules. 5. The method of claim 4,
the plurality of first conductive wires and the interconnector are connected in a plurality of first connection regions;
An area of one of the plurality of first connection regions is different from an area of another one of the plurality of first connection regions. 5. The method of claim 4,
the plurality of first conductive wires and the interconnector are connected in a plurality of first connection regions;
A solar cell module wherein an end of one of the plurality of first connection regions in a second direction does not overlap with an end of the other of the plurality of first connection regions in the first direction in the first direction. The method of claim 1,
An area of a first connection region to which the first conductive wiring and the interconnector are connected and an area of a second connection region to which the second conductive wiring and the interconnector are connected are different from each other. The method of claim 1,
A first connection region to which the first conductive wiring and the interconnector are connected, and a second connection region to which the second conductive wiring and the interconnector are connected, are the semiconductor substrates of the first solar cell and the second solar cell. A solar cell module placed in an external area. The method of claim 1,
A sum of a length in a second direction of a region overlapping the first conductive line and the interconnector in the first direction and a length in a second direction of a region overlapping the second conductive line and the interconnector in the first direction is a solar cell module greater than a length in the second direction of the interconnector. The method of claim 1,
a second direction length of a region overlapping the first conductive line and the interconnector in the first direction is greater than half a length of the interconnector in the second direction;
A second direction length of a region overlapping the second conductive line and the interconnector in the first direction is less than half a length of the interconnector in the second direction. The method of claim 1,
An area of a first application region of an adhesive disposed between the first conductive wiring and the interconnector is different from an area of a second application region of an adhesive disposed between the second conductive wiring and the interconnector. The method of claim 1,
The first spacing in the second direction between the interconnector and the semiconductor substrate of the first solar cell includes a second spacing in the second direction between the interconnector and the semiconductor substrate of the second solar cell; different solar modules.

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