KR101542002B1 - Solar cell module - Google Patents

Abstract

The present invention relates to a solar cell module.
An example of a solar cell module according to the present invention includes a first solar cell and a second solar cell including a semiconductor substrate and a first electrode and a second electrode formed on a rear surface of the semiconductor substrate, And a conductive wiring connected to one of the first electrode and the second electrode by a conductive adhesive so that the first and second solar cells are electrically connected in series with each other, The connection width of the bonded region is larger than the wiring width of the conductive wiring.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module.

A typical solar cell has a substrate made of different conductivity type semiconductors, such as p-type and n-type, an emitter, and an electrode 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.

The solar cell using the semiconductor substrate can be divided into various types such as a conventional type and a rear type depending on the structure.

In the conventional type, the emitter portion is located on the front surface of the substrate, the electrode connected to the emitter portion is disposed on the front surface of the substrate, the electrode connected to the substrate is positioned on the rear surface of the substrate, And all of the electrodes are located on the rear surface of the substrate.

Since the electrodes of the rear contact type solar cell are all formed on the rear surface of the substrate, the electrodes formed on the rear surface of the substrate are connected in series to the electrodes of the adjacent solar cells via the interconnector or another conductive metal to form the solar cell module .

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

An example of a solar cell module according to the present invention includes a first solar cell and a second solar cell including a semiconductor substrate and a first electrode and a second electrode formed on a rear surface of the semiconductor substrate, And a conductive wiring connected to one of the first electrode and the second electrode by a conductive adhesive so that the first and second solar cells are electrically connected in series with each other, The connection width of the bonded region is larger than the wiring width of the conductive wiring.

At this time, the connection width direction and the wiring width direction may be the same. In addition, when the conductive wiring is provided in the form of a wire, the wiring width may be the diameter of the wire.

In this case, the ratio of the connection width to the connection width may be between 1: 1.2 to 2.0, for example, the connection width is between 200 mu m and 600 mu m, and the connection width is between 240 mu m and 1200 mu m Lt; / RTI >

Further, a conductive adhesive may be coated on the surface of the connection portion connected to at least one of the cell electrodes among the conductive wires.

At this time, the thickness of the conductive adhesive located on the first surface between one of the cell electrodes and the conductive wirings on the surface of the connection portion of the conductive wirings is preferably set so that the thickness of the second surface May be greater than the thickness of the conductive adhesive disposed on the conductive adhesive layer.

For example, the thickness of the conductive adhesive located on the first surface may be between 10 탆 and 40 탆, and the thickness of the conductive adhesive located on the second surface may be between 1 탆 and 3 탆.

The first and second solar cells are arranged in a direction crossing the longitudinal direction of the first and second electrodes of the first and second solar cells, And may be formed in a direction crossing the longitudinal direction of the first and second electrodes.

The plurality of conductive wirings include a first conductive wiring connected to the first electrode of the first solar cell and a second conductive wiring connected to the second electrode of the first solar cell, The first conductive wiring and the second electrode of the first solar cell are insulated from each other by an insulating layer of an insulating material at a portion intersecting with the second electrode of the battery and the second conductive wiring is crossed with the first electrode of the first solar cell The second conductive wiring and the first electrode of the first solar cell can be insulated from each other by the insulating layer.

In addition, for the series connection of the first and second solar cells, the first conductive wiring may be connected to the second electrode of the second solar cell, or the second conductive wiring may be connected to the first electrode of the second solar cell.

As described above, in the solar cell module according to the present invention, the connection width of the conductive line adhesive bonded to the cell electrode is formed larger than the width of the conductive interconnection, so that the conductive interconnection can be more stably bonded to the cell electrode.

1 and 2 are views for explaining an example of a solar cell module according to the present invention.
Fig. 3 is a diagram for explaining the conductive adhesive agent CA shown in Fig. 1 in more detail.
4 is a view for explaining an example of a solar cell applicable to the solar cell module shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention in the drawings, portions not related to the description are omitted, and like reference numerals are given to similar portions throughout the specification.

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

Hereinafter, a solar cell module according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a rear view of a solar cell module according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. 1. FIG. .

1, a solar cell module according to the present invention includes a plurality of solar cells each including a first solar cell C1 and a second solar cell C2, And wirings CW1 and CW2.

Here, each of the plurality of solar cells includes a semiconductor substrate 110, a plurality of first electrodes C141, and a plurality of second electrodes C142.

Here, the semiconductor substrate 110 may include crystalline silicon or amorphous silicon, and a p-n junction may be formed on the semiconductor substrate 110 to generate electricity from the incident light.

The first electrode (C141) and the second electrode (C142) may be spaced apart from each other on the rear surface of the semiconductor substrate (110). Such a solar cell will be described in more detail in Fig. 4 below.

The conductive wires CW1 and CW2 are formed by electrically connecting a plurality of solar cells including the first and second solar cells C1 and C2 to each other in series and electrically connecting the first electrode C141 or the second electrode C142 (C141 or C142) among the plurality of cell electrodes (C141 or C142).

Here, the conductive adhesive (CA) is not particularly limited as long as it is a conductive material, but a conductive material having a melting point at a relatively low temperature of 140 ° C to 180 ° C is more preferable. However, the melting point is not necessarily limited to this, and the melting point may vary.

For example, the conductive adhesive (CA) may be a conductive paste such as a solder paste or a conductive paste in which conductive metal particles are contained in an insulating resin, a conductive material such as a conductive adhesive film, or the like.

In addition, the conductive wirings CW1 and CW2 may be provided in the form of a ribbon or a wire. When the conductive wirings CW1 and CW2 are provided in the form of a ribbon or a wire, the manufacturing process of the solar cell module is simple and the material cost is low, thereby further reducing the manufacturing cost of the solar cell module.

The conductive wirings CW1 and CW2 may be formed of a material having good conductivity such as copper (Cu) or silver (Ag).

In such a solar cell module, the first and second solar cells C1 and C2 are arranged in a direction intersecting the longitudinal direction of the first and second electrodes C141 and C142 of the first and second solar cells C1 and C2 Lt; / RTI > 1, the longitudinal direction of the first and second electrodes C141 and C142 of each solar cell may be a first direction x, and the lengths of the first and second solar cells C1 and C2, May be arranged in a second direction (y).

The longitudinal direction of the plurality of conductive wirings CW1 and CW2 is formed in a direction crossing the longitudinal direction of the first and second electrodes C141 and C142 of the first and second solar cells C1 and C2. For example, the longitudinal direction of the plurality of conductive wirings CW1 and CW2 may be the second direction y.

As shown in FIGS. 1 and 2, the plurality of conductive wirings CW1 and CW2 include first conductive wirings CW1 and CW2 connected to the first electrode C141 of the first solar cell C1, And second conductive wirings CW1 and CW2 connected to the second electrode C142 of the first solar cell C1.

 The first conductive wirings CW1 and CW2 may be connected to the second electrode C142 of the second solar cell C2 for the series connection of the first and second solar cells C1 and C2, CW1 and CW2 may be connected to the first electrode C141 of the second solar cell C2.

1 and 2, a portion of the first conductive interconnects CW1 and CW2 that intersects the second electrode C142 of the first solar cell C1 is an insulating layer IL of an insulating material, The first conductive interconnects CW1 and CW2 and the second electrode C142 of the first solar cell C1 can be insulated from each other.

The portions of the second conductive interconnections CW1 and CW2 that intersect the first electrode C141 of the first solar cell C1 are electrically connected to the second conductive interconnections CW1 and CW2 and the first The first electrode C141 of the solar cell C1 can be insulated from each other.

Here, the insulating layer IL may be formed to include an insulating resin such as an epoxy.

Meanwhile, in the solar cell module according to FIGS. 1 and 2, one conductive wiring (CW1, CW2) is directly connected to the electrodes of two adjacent solar cells in order to connect a plurality of solar cells in series Alternatively, the conductive wirings CW1 and CW2 may be provided separately for each solar cell, and in such a case, a separate interconnector (not shown) may be provided.

That is, the respective conductive wires CW1 and CW2 are provided on the rear surface of each solar cell, and each of the conductive wires CW1 and CW2 is connected to a separate interconnector so that a plurality of solar cells can be connected in series.

In addition, in the solar cell module according to FIGS. 1 and 2, the arrangement direction of the solar cells is arranged to intersect the longitudinal direction of the cell electrode (C141 or C142) formed in each solar cell, and the longitudinal direction of the conductive wires (CW1, CW2) (C141 or C142) formed in each solar cell is arranged to cross the longitudinal direction of the cell electrode (C141 or C142).

Alternatively, however, it is also possible that the array direction of the solar cells and the longitudinal direction of the conductive wires CW1 and CW2 are arranged or arranged in the same direction as the longitudinal direction of the cell electrodes C141 or C142.

Fig. 3 is a diagram for explaining the conductive adhesive agent CA shown in Fig. 1 in more detail.

Here, FIG. 3 (a) is an enlarged view of a portion B in FIG. 1, and FIG. 3 (b) shows a cross section along an X-X line in FIG.

3A, a solar cell module according to the present invention includes a conductive adhesive agent (for example, a conductive adhesive agent (for example, a conductive adhesive agent CA) may be coated.

Therefore, the conductive adhesive agent (CA) may be positioned on the first surface and the second surface among the surfaces of the connecting portions of the conductive wires (CW1, CW2).

Here, the first surface may be between any one of the cell electrodes (C141 or C142) and the conductive wires (CW1, CW2) on the surface of the connection portion of the conductive wires (CW1, CW2) And may be the surface of the conductive wirings CW1 and CW2 located on the opposite sides.

Thus, the conductive wires CW1 and CW2 are connected to any one of the cell electrodes C141 or C142 so that the conductive adhesive CA is positioned on the first surface and the second surface of the connection portion of the conductive wires CW1 and CW2 The connection portions of the conductive wirings CW1 and CW2 can be protected from the external environment.

3B, the connection width WE of the region where the conductive adhesive CA is bonded to one of the cell electrodes C141 or C142 is smaller than the connection width WE of the conductive wires CW1 and CW2 May be greater than the width R1.

Here, when the conductive wirings CW1 and CW2 are provided in the form of a wire, the wiring width R1 may be the diameter of the wire. The direction of connection width WE and the direction of wiring width R1 may be the same. That is, both the connection width WE and the wiring width R1 directions may be the first direction x.

As described above, by making the connection width WE of the conductive adhesive CA larger than the wiring width R1 of the conductive wirings CW1 and CW2, the conductive wirings CW1 and CW2 and any one of the cell electrodes C141 or C142, It is possible to further improve the contact force between the electrodes and further reduce the contact resistance.

Therefore, the adhesive strength of the connection portions of the conductive wires CW1 and CW2 connected to one of the cell electrodes C141 and C142 may be weakened due to the external environment, or the conductive wires CW1 and CW2 may contact the cell electrode C141 or C142 Can be minimized.

Here, the ratio of the connection width WE to the wiring width Rl may be between 1: 1.2 and 2.0.

For example, the wiring width R 1 may be between 200 μm and 600 μm, and the connection width WE may be between 240 μm and 1200 μm within a range larger than the wiring width R 1.

If the ratio of the connection width WE to the wiring width R 1 is 1: 1.2 or more, the minimum contact force and contact resistance can be ensured and the ratio of the connection width WE to the wiring width R 1 is 1: 2 or less, it is possible to prevent the connection area of the conductive adhesive CA from becoming excessively large and short-circuiting with the adjacent cell electrode C141 or C142 having the opposite polarity.

That is, if the connection width WE of the conductive adhesive CA in the first direction (x) becomes excessively large, the connection area of the conductive adhesive CA as a whole increases so that the connection width WE in the second direction y And in such a case, it may be short-circuited with the adjacent cell electrode (C141 or C142) of the opposite polarity. By appropriately limiting the ratio of the connection width WE as in the present invention, short circuit can be prevented .

In the present invention, the thickness T2 of the conductive adhesive CA located on the first surface among the surfaces of the connection portions of the conductive wires CW1 and CW2 is greater than the thickness T1 of the conductive adhesive CA located on the second surface ).

The thickness T 1 of the conductive adhesive CA located on the first surface may be between 10 μm and 40 μm and the thickness T 1 of the conductive adhesive CA located on the second surface may be between 1 μm and 10 μm, Mu] m.

As described above, the present invention is characterized in that the thickness T2 of the conductive adhesive CA positioned on the first surface of the conductive wires CW1 and CW2 is set to be larger than the thickness T2 of the conductive adhesive CA positioned on the second surface of the conductive wires CW1 and CW2. The contact resistance and the contact resistance between the conductive wires CW1 and CW2 and the cell electrode C141 or C142 can be further improved.

Hereinafter, an example of a solar cell applicable to the solar cell module shown in FIG. 1 will be described.

4 is a view for explaining an example of a solar cell applicable to the solar cell module shown in FIG.

Referring to FIG. 4, an example of a solar cell according to the present invention includes a semiconductor substrate 110, an antireflection film 130, an emitter 121, a back surface field (BSF) 172, (C141) and a second electrode (C142).

Here, the antireflection film 130 and the backside electrical part 172 may be omitted. Hereinafter, the antireflection film 130 and the backside electrical part 172 will be described with reference to FIG. 4 as an example.

The semiconductor substrate 110 may be a semiconductor substrate 110 of a first conductivity type, for example, n-type conductivity type silicon. The semiconductor substrate 110 may be formed by doping a first conductivity type impurity into a semiconductor wafer formed of a crystalline silicon material.

The emitter portions 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. The plurality of emitter portions 121 may include a second conductive type, for example, a p-type conductive type impurity opposite to the conductive type of the semiconductor substrate 110. [

Accordingly, a p-n junction can be formed by the semiconductor substrate 110 and the emitter section 121.

The plurality of emitter portions 121 may be disposed in the same direction as the plurality of emitter portions 121. The plurality of emitter portions 121 may be spaced apart from each other in a direction parallel to the emitter portions 121, have. Accordingly, as shown in FIG. 4, a plurality of emitter sections 121 and a plurality of rear electric sections 172 may be alternately arranged on the rear surface of the semiconductor substrate 110.

The plurality of rear electric field sections 172 may be an impurity having the same conductivity type as the semiconductor substrate 110 and containing impurities at a higher concentration than the semiconductor substrate 110, for example, an n ++ part.

The plurality of first electrodes C141 may be physically and electrically connected to the emitter section 121 and may be formed on the rear surface of the semiconductor substrate 110 along the emitter section 121. [

The plurality of second electrodes C142 are formed on the rear surface of the semiconductor substrate 110 along the plurality of rear electric sections 172 and electrically connected to the semiconductor substrate 110 through the rear electric section 172, .

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

The holes collected through the first electrode (C141) and the electrons collected through the second electrode (C142) in the solar cell according to the present invention manufactured using the above structure are used as electric power of the external device through the external circuit device .

Here, each of the plurality of first electrodes C141 may extend in a first direction x, as shown in FIG. 1, and each of the plurality of first electrodes C141 may extend in a first direction x, In a second direction (y) intersecting the first direction (y).

Each of the plurality of second electrodes C142 may extend in a first direction x as shown in Fig. 1, and each of the plurality of second electrodes C142 may extend in a first direction x, (Y) in the second direction (y).

In addition, the first and second electrodes C141 and C142 may be spaced apart from each other, and the first electrode C141 and the second electrode C142 may be alternately arranged.

The solar cell applied to the solar cell module according to the present invention is not necessarily limited to FIG. 4 except that the first and second electrodes C141 and C142 provided in the solar cell are formed only on the rear surface of the semiconductor substrate 110 Any other component can be changed.

For example, each of the first and second electrodes C141 and C142 does not extend in the first direction x but can be arranged in the form of a dot spaced apart from each other in the first direction x. In addition, A first bus bar (not shown) extends in a second direction y so as to be commonly connected to all of the plurality of first electrodes C141 at one end of the first direction x on the rear surface of the substrate 110 The second electrode (C142) extends in the second direction (y) so as to be commonly connected to all of the second electrodes (C142) at the other end of the first direction (x) on the rear surface of the semiconductor substrate (110) It is also possible that a bus bar (not shown) is further provided.

It will be apparent to those skilled in the art that various modifications, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. will be. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are intended to illustrate and not to limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (13)

A first solar cell and a second solar cell including a semiconductor substrate and a first electrode and a second electrode spaced apart from each other on a rear surface of the semiconductor substrate and disposed immediately adjacent to each other; And
And a conductive wiring connected to one of the first electrode and the second electrode by a conductive adhesive so that the first and second solar cells are electrically connected to each other in series,
The connection width of the region where the conductive adhesive is bonded to any one of the cell electrodes is larger than the wiring width of the conductive wiring, the ratio of the connection width to the wiring width is between 1: 1.2 and 2.0,
Wherein the conductive adhesive is coated on at least a surface of the connection portion connected to at least one of the cell electrodes among the conductive wires,
The thickness of the conductive adhesive coated on the first surface between the one of the cell electrodes and the conductive interconnection among the surfaces of the connection portion of the conductive interconnection is set to a position opposite to the first surface among the surfaces of the connection portion of the conductive interconnection Wherein the thickness of the conductive adhesive is greater than the thickness of the conductive adhesive coated on the second surface,
Wherein the thickness of the conductive adhesive located on the first surface is between 10 탆 and 40 탆 and the thickness of the conductive adhesive located on the second surface is between 1 탆 and 3 탆. The method according to claim 1,
Wherein the connection width direction and the wiring width direction are the same. The method according to claim 1,
Wherein the conductive wiring is provided in the form of a wire, and the wiring width is a diameter of the wire. delete The method according to claim 1,
Wherein the wiring width is between 200 mu m and 600 mu m. The method according to claim 1,
Wherein the connection width is between 240 mu m and 1200 mu m within a range larger than the wiring width.
delete delete delete delete The method according to claim 1,
Wherein the first and second solar cells are arranged in a direction crossing the longitudinal direction of the first and second electrodes of the first and second solar cells,
Wherein the longitudinal direction of the plurality of conductive wirings is formed in a direction crossing the longitudinal direction of the first and second electrodes of the first and second solar cells. 12. The method of claim 11,
Wherein the plurality of conductive wirings include a first conductive wiring connected to a first electrode of the first solar cell and a second conductive wiring connected to a second electrode of the first solar cell,
The first conductive wiring and the second electrode of the first solar cell are insulated from each other by an insulating layer of an insulating material at a portion where the first conductive wiring crosses the second electrode of the first solar cell,
And the second conductive wiring and the first electrode of the first solar cell are insulated from each other by the insulating layer at a portion where the second conductive wiring crosses the first electrode of the first solar cell. 13. The method of claim 12,
For the series connection of the first and second solar cells,
The first conductive wiring may be connected to the second electrode of the second solar cell,
And the second conductive wiring is connected to the first electrode of the second solar cell.

Images