KR102394105B1 - Solar cell module - Google Patents

Abstract

The present invention relates to a solar cell module.
A solar cell module according to an example of the present invention includes: a plurality of solar cells each having a semiconductor substrate, a plurality of first electrodes elongated in a first direction on the front surface of the semiconductor substrate, and a second electrode on the rear surface of the semiconductor substrate; and a first electrode of a first solar cell and a second electrode of a second solar cell adjacent to the first solar cell among the plurality of solar cells, and disposed in a second direction intersecting the first direction to form a plurality of solar cells a plurality of conductive wires electrically connecting the plurality of first electrodes, wherein at least one first electrode of the plurality of first electrodes includes a first portion that is disconnected at an intersection crossing the plurality of conductive wires, and at least a portion of the conductive wires It is buried in the first part provided in one first electrode.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module.

Recently, as the depletion of existing energy resources such as oil and coal is predicted, interest in alternative energy to replace them is increasing, and accordingly, solar cells that produce electric energy from solar energy are attracting attention.

A typical solar cell includes a semiconductor portion that forms a p-n junction by different conductive types such as p-type and n-type, and electrodes connected to semiconductor portions of different conductivity types.

When light is incident on such a solar cell, a plurality of electron-hole pairs are generated in the semiconductor part, and the generated electron-hole pairs are separated into electrons and holes, which are charges, respectively, and the electrons move toward the n-type semiconductor part and the holes are p It moves toward the semiconductor part of the mold. The moved electrons and holes are collected by different electrodes connected to the n-type semiconductor part and the p-type semiconductor part, respectively, and power is obtained by connecting these electrodes with wires.

Such solar cells may be connected to each other by conductive wiring for mutual connection.

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

A solar cell module according to an example of the present invention includes: a plurality of solar cells each having a semiconductor substrate, a plurality of first electrodes elongated in a first direction on the front surface of the semiconductor substrate, and a second electrode on the rear surface of the semiconductor substrate; and a first electrode of a first solar cell and a second electrode of a second solar cell adjacent to the first solar cell among the plurality of solar cells, and disposed in a second direction intersecting the first direction to form a plurality of solar cells a plurality of conductive wires electrically connecting the plurality of first electrodes, wherein at least one first electrode of the plurality of first electrodes includes a first portion that is disconnected at an intersection crossing the plurality of conductive wires, and a portion of the conductive wires is at least It is buried in the first part provided in one first electrode.

Here, at the crossing point, a portion of the conductive wiring may be located in a space between both side surfaces of the at least one first electrode exposed to the first portion.

More specifically, an anti-reflection film made of a dielectric material is further formed on the front surface of the semiconductor substrate, and each of the plurality of first electrodes penetrates the anti-reflection film and is connected to the front surface of the semiconductor substrate, at the intersection between a portion of the conductive wiring and the anti-reflection film. The gap may be smaller than a height at which the first electrode protrudes through the anti-reflection layer.

In addition, at the crossing point, the conductive wiring may be connected to the side surface and the upper surface of the at least one first electrode exposed to the first portion through a conductive adhesive.

In addition, a gap between a portion of the conductive wiring and the anti-reflection layer in the remaining portion except for the intersection may be smaller than a height at which the first electrode protrudes through the anti-reflection layer.

For example, all of the plurality of first electrodes may include the first portion at the intersection point.

Also, a first interval between both side surfaces of the at least one first electrode exposed to the first portion at the crossing point may be smaller than a line width of the conductive wiring.

Here, the first interval may be 5% to 80% or less of the line width of the conductive wiring. For example, the line width of the conductive wiring may be between 250 μm and 350 μm, and the first interval may be between 200 μm and 280 μm in a range smaller than the line width of the conductive wiring.

Such a conductive wiring may include a core made of a conductive material and a coating layer that coats the surface of the core and includes tin.

In this case, the core of the conductive wiring may be buried in the first portion.

Here, the diameter of the core may be between 200 μm and 310 μm, and the thickness of the coating layer may be between 10 μm and 20 μm.

In addition, the protrusion height at which the first electrode protrudes through the anti-reflection layer may be between 10 μm and 30 μm, and the interval between a portion of the conductive wiring and the anti-reflection layer may be 20 μm or less in a range smaller than the protrusion height.

In addition, among the plurality of first electrodes, some edge first electrodes positioned at the edges of the semiconductor substrate in the second direction have a first portion at the crossing points, and the remaining first electrodes excluding some edge first electrodes are disposed at the crossing points. The first part may not be provided.

Here, the number of some edge first electrodes having the first portion may be between 1 and 5.

In addition, both ends of the first portion of the outermost first electrode positioned at the outermost among some of the first electrodes may further include a guide portion protruding in the second direction.

Here, the interval between the guide portions provided at both ends of the first portion of the outermost first electrode may be smaller than the line width of the conductive wiring.

In addition, a connection electrode formed at the intersection of the remaining first electrodes and extending in the second direction to connect the remaining first electrodes to each other may be provided.

In addition, a pad part having a width greater than the line width of the first electrode or the line width of the connection electrode may be further located at at least some of the intersection points of the remaining first electrodes.

In the solar cell module according to the present invention, a part of the conductive wiring is buried in the electrode and connected to the electrode, so that the contact force between the electrode and the conductive wiring is strengthened, and the space between the conductive wiring and the semiconductor substrate is minimized, so that the conductive wiring is corroded. can be prevented from becoming

Thereby, the reliability of a solar cell module can be improved more

1 is an exploded perspective view schematically illustrating a solar cell module according to an example of the present invention.
FIG. 2 is a view for explaining an example of a connection structure of a plurality of solar cells shown in FIG. 1 .
3 is a view for explaining an example of the structure of each solar cell.
FIG. 4 is a view for explaining the first portion P1 included in the plurality of first electrodes 140 illustrated in FIG. 3 .
FIG. 5 is a diagram for explaining a structure in which the conductive wiring 200 is connected to the first portion P1 of the first electrode 140 .
6 is a view for explaining the present invention and another comparative example.
7 is a view showing a partial appearance when the solar cell module according to the present invention is laminated.
8 is a view for explaining another example of the first portion P1 included in the first electrode 140 in the solar cell module according to the present invention.
9 is a road for explaining a solar cell module according to another example of the present invention, and describes a case in which only some of the first electrodes 140 among all of the plurality of first electrodes 140 include the first portion P1. It is a way to do

Hereinafter, with reference to the accompanying drawings, the 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 several different 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 attached to similar parts throughout the specification.

In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. When a part, such as a layer, film, region, plate, etc., is "on" another part, it includes not only the case where it is "directly on" another part, but also the case where there is another part in between. Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle. Also, when it is said that a part is formed “whole” on another part, it means that it is formed on the entire surface of the other part as well as that it is not formed on a part of the edge.

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

In addition, in the following description, the meaning that the length or width of two different components are the same means that they are the same within an error range of 10%.

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

1 is an exploded perspective view schematically illustrating a solar cell module according to an example of the present invention.

The solar cell module according to the present invention may include a front transparent substrate 40 , a first filling sheet 30a , a plurality of solar cells, a second filling sheet 30b , and a rear sheet 50 .

The front transparent substrate 40 may be made of tempered glass having high transmittance and excellent damage prevention function. For example, the tempered glass may be a low iron tempered glass having a low iron content.

Each of the plurality of solar cells functions to convert incident solar energy into electrical energy, and for this purpose, the semiconductor substrate 110 doped with impurities, various functional layers, and electrodes may be provided.

The rear substrate 50 may prevent moisture from penetrating the rear surfaces of the solar cells, thereby protecting the solar cells from the external environment.

The rear substrate 50 may be disposed on the rear surface of the front transparent substrate 40 to face the front transparent substrate 40 with a solar cell disposed therebetween.

The rear substrate 50 may be in the form of a sheet or a glass substrate, and may have a multi-layered structure such as a layer preventing moisture and oxygen penetration, a layer preventing chemical corrosion, and a layer having insulating properties.

The filling sheet 30 may include a first filling sheet 30a positioned between the front transparent substrate 40 and the plurality of solar cells and a second filling sheet 30b positioned between the plurality of solar cells and the rear substrate. can

Such a filling sheet 30 may prevent corrosion due to moisture penetration and protect the solar cell from impact. The filling sheet 30 may be made of a material such as ethylene vinyl acetate (EVA).

In addition, such a filling sheet 30 is integrated with the solar cells by a lamination process in a state in which they are respectively disposed above and below the solar cells, fills the space between the solar cells, and can be cured through heat treatment. .

In such a solar cell module, a structure of each of the plurality of solar cells and a connection structure in which the plurality of solar cells are connected will be described in more detail as follows.

FIG. 2 is a diagram illustrating an example of a connection structure of a plurality of solar cells illustrated in FIG. 1 , and FIG. 3 is a diagram illustrating an example of a structure of each solar cell.

Here, FIG. 2(a) shows a planar structure in which a plurality of solar cells are connected by a plurality of conductive wirings 200, and FIG. 2(b) is a line CS1-CS1 in FIG. 2(a). A cross-section along the line CS2-CS2 in FIG. 2(a) is shown in FIG. 2(c).

2 and 3 , each of the plurality of solar cells includes a semiconductor substrate 110 and a plurality of first electrodes 140 elongated in the first direction (x) on the front surface of the semiconductor substrate 110 and , the second electrode 150 may be provided on the rear surface of the semiconductor substrate 110 .

The plurality of solar cells C1 and C2 are arranged spaced apart from each other in a second direction y intersecting the first direction x, and are adjacent to each other in the second direction y, as shown in FIG. 2 . The first and second solar cells C1 and C2 may be included.

The plurality of conductive wirings 200 are arranged to extend in the second direction y, and are connected to the first electrode 140 of the first solar cell C1 and the second electrode 150 of the second solar cell C2. The first and second solar cells C1 and C2 connected to each other and adjacent to each other in the second direction y may form a string.

The conductive wiring 200 may have a circular or elliptical cross-section and may be a long wire.

In this case, the number N200 of the plurality of conductive wirings 200 may be 6 to 33 based on one surface of the solar cell. In addition, the width W200 of each of the plurality of conductive wirings 200 may be between 250 μm and 500 μm.

For example, when the line width W200 of the conductive wiring 200 is 250 μm or more and less than 300 μm, the number N200 of the conductive wiring 200 may be 15 to 33.

In addition, when the line width W200 of the conductive wiring 200 is 300 μm or more and less than 350 μm, the number N200 of the conductive wiring 200 may be 10 to 15, and the line width W200 of the conductive wiring 200 is When more than 350um and less than 400um, the number N200 of the conductive wires 200 may be 8 to 10, and when the line width W200 of the conductive wires 200 is 400um to 500um, the number of conductive wires 200 (N200) may be 6 to 8.

As such, by arranging the number N200 of the conductive wires 200 differently according to the line width W200 of the conductive wires 200, total shading covered by the conductive wires 200 on the light-receiving surface of the solar cell ) while not increasing the area, the self-resistance of the conductive wiring 200 can be appropriately adjusted, thereby minimizing the output reduced by the conductive wiring 200, and further improving the output of the solar cell module can do it

The relationship between the number according to the line width W200 of the conductive wiring 200 described above is one example of optimization, and the present invention is not necessarily limited thereto.

In addition, the pitch between the two conductive wires 200 adjacent to each other may be formed between 4.75 mm and 25.13 mm in consideration of the line width W200 and the number of the conductive wires 200 .

As shown in FIG. 3 , each of the plurality of solar cells includes a semiconductor substrate 110 , an emitter unit 120 , an anti-reflection film 130 , a first electrode 140 , and a back surface field unit 172 . , BSF), a back protection layer 180 , and a second electrode 150 may be provided.

The semiconductor substrate 110 may have a first conductivity type, for example, a p-type or an n-type conductivity type, and the semiconductor substrate 110 may be formed of any one of single crystal silicon, polycrystalline silicon, or amorphous silicon. there is. For example, the semiconductor substrate 110 may be formed of a crystalline silicon wafer.

Specifically, when the semiconductor substrate 110 has a p-type conductivity, impurities of a trivalent element such as 2 boron, gallium, and indium may be doped into the semiconductor substrate 110 .

However, when the semiconductor substrate 110 has an n-type conductivity type, impurities of a pentavalent element such as phosphorus (P), arsenic (As), or antimony (Sb) may be doped into the semiconductor substrate 110 . .

The front surface of the semiconductor substrate 110 has a plurality of uneven surfaces. 3 , only the edge of the semiconductor substrate 110 is illustrated as a concave-convex surface, but substantially the entire front surface of the semiconductor substrate 110 has a concave-convex surface. 120 and the anti-reflection layer 130 may also have an uneven surface.

As shown in FIG. 3 , the emitter unit 120 is formed on the front surface, which is the incident surface, of the semiconductor substrate 110 of the first conductivity type, and is of a second conductivity type opposite to the first conductivity type, for example, n As a region doped with a conductive type impurity in the semiconductor substrate 110 , it may be located on the surface on which light is incident, that is, inside the front surface of the semiconductor substrate 110 .

Accordingly, the emitter portion 120 of the second conductivity type forms a p-n junction with the portion of the first conductivity type of the semiconductor substrate 110 .

The light incident on the semiconductor substrate 110 is separated into electrons and holes, so that the electrons move toward the n-type and the holes move toward the p-type. Accordingly, when the semiconductor substrate 110 is p-type and the emitter unit 120 is n-type, the separated holes may move toward the rear surface of the semiconductor substrate 110 and the separated electrons may move toward the emitter unit 120 .

Since the emitter unit 120 forms a p-n junction with the semiconductor substrate 110 , that is, the first conductive portion of the semiconductor substrate 110 , the semiconductor substrate 110 has an n-type conductivity type, unlike this embodiment. In this case, the emitter part 120 may have a p-type conductivity type. In this case, the separated electrons may move toward the rear surface of the semiconductor substrate 110 and the separated holes may move toward the emitter unit 120 .

When the emitter portion 120 has an n-type conductivity type, the emitter portion 120 may be formed by doping the semiconductor substrate 110 with impurities of a pentavalent element. Conversely, when it has a p-type conductivity type, It may be formed by doping the semiconductor substrate 110 with impurities of a trivalent element.

The anti-reflection film 130 is located on the incident surface of the semiconductor substrate 110, and as shown in FIGS. 3 and 5, when the emitter unit 120 is located on the incident surface of the semiconductor substrate 110, The anti-reflection layer 130 may be located on the emitter unit 120 .

The anti-reflection film 130 may be formed of a dielectric material, and for example, at least one of a hydrogenated silicon nitride film (SiNx:H), a hydrogenated silicon oxide film (SiOx:H), and a hydrogenated silicon nitride oxide film (SiNxOy:H). Either one may be formed of a plurality of layers.

In this way, the passivation function of the antireflection film 130 can be further strengthened, and the photoelectric efficiency of the solar cell can be further improved.

As shown in FIG. 3 , the plurality of first electrodes 140 are positioned on the front surface of the semiconductor substrate 110 , are spaced apart from each other on the front surface of the semiconductor substrate 110 , and are each positioned in the first direction (x). It can be positioned elongated.

In this case, the plurality of first electrodes 140 may penetrate the anti-reflection layer 130 and may be electrically connected to the emitter unit 120 .

Accordingly, the plurality of first electrodes 140 may be made of at least one conductive material such as silver (Ag), and may collect electric charges, for example, electrons that have moved toward the emitter unit 120 .

In addition, as shown in FIG. 3 , each of the plurality of first electrodes 140 may include a first portion P1 that is cut off at an intersection where it overlaps and intersects with the plurality of conductive wirings 200 .

That is, in each of the plurality of first electrodes 140 extending long in the first direction (x), as shown in FIG. 3 , the first electrode 140 is not formed at the intersection point crossing the plurality of conductive wires 200 , and the The tab portion 120 may include a first portion P1 covered with an anti-reflection film 130 .

In addition, the plurality of conductive wirings 200 may overlap and cross the first portion P1 of each of the plurality of first electrodes 140 .

The rear electric field unit 172 may be located on the rear surface opposite to the front surface of the semiconductor substrate 110 , and is a region doped with impurities of the same first conductivity type as that of the semiconductor substrate 110 at a higher concentration than the semiconductor substrate 110 . , for example, a P+ region.

Such a rear electric field unit 172 may be overlapped with a second electrode 150 pattern to be described later and formed to be elongated in the first direction (x), and may be formed in the form of a plurality of lines spaced apart in the second direction (y). there is. Accordingly, the rear electric field unit 172 may be composed of a plurality of rear electric field unit lines 172 .

A potential barrier is formed due to a difference in impurity concentration between the first conductive region of the semiconductor substrate 110 and the rear electric field unit 172, which prevents electron movement toward the rear electric field unit 172, which is the movement direction of holes. On the other hand, it is possible to facilitate hole movement toward the rear electric field unit 172 .

Accordingly, the amount of charge lost due to recombination of electrons and holes in and near the rear surface of the semiconductor substrate 110 is reduced and the movement of a desired charge (eg, hole) is accelerated to reduce the amount of charge transfer to the second electrode 150 . can increase

The back passivation layer 180 may be formed to cover the entire rear surface of the semiconductor substrate 110 except for the portion where the second electrode 150 is formed, and may perform a passivation function and an insulating function for the rear surface of the semiconductor substrate 110 . there is. The back passivation layer 180 may be formed of at least one layer of at least one of silicon nitride (SiNx), silicon oxide (SiOx), or silicon oxynitride (SiNxOy).

The second electrode 150 is formed on the rear surface of the semiconductor substrate 110 opposite to the one surface in a first direction (x) in a lengthwise parallel to each other, and is formed in a second direction (y) intersecting the first direction (x). It may be formed spaced apart. However, such a pattern of the second electrode 150 is an example, and is not necessarily limited thereto.

The second electrode 150 overlaps with the above-described rear electric field unit 172 and is electrically connected to collect charges, for example, holes, moving from the rear electric field unit 172 side.

At this time, since the second electrode 150 is in contact with the rear electric field unit 172 maintained at a higher impurity concentration than that of the semiconductor substrate 110 , that is, the contact resistance between the rear electric field unit 172 and the second electrode 150 . Due to this decrease, charge transfer efficiency from the semiconductor substrate 110 to the second electrode 150 may be improved.

A conductive wire 200 is connected to the second electrode 150 , so that charges (eg, holes) collected in the second electrode 150 can be transferred to another adjacent solar cell through the conductive wire 200 . .

The second electrode 150 may include a metal material having good conductivity, for example, at least one conductive material such as silver (Ag).

The operation of the solar cell according to the present embodiment having such a structure is as follows.

When light is irradiated to the solar cell and is incident on the emitter unit 120 that is the semiconductor unit and the semiconductor substrate 110 through the emitter unit 120 , electron-hole pairs are generated in the semiconductor unit by the light energy. Such an electron-hole pair is separated from each other by the p-n junction of the semiconductor substrate 110 and the emitter part 120 so that electrons and holes are, for example, the emitter part 120 having an n-type conductivity type and the rear front surface. Each moves toward the step unit 172 . In this way, electrons moving toward the emitter unit 120 are collected by the first electrode 140 and transferred to the conductive wiring 200 , and holes moving toward the rear electric field unit 172 are transferred to the second electrode 150 by the second electrode 150 . It may be collected and transferred to the conductive wiring 200 .

So far, the overall configuration of the solar cell module according to an example of the present invention, the connection relationship between the plurality of solar cells, and the structure of each solar cell have been described.

Hereinafter, a connection relationship between the first portion P1 of the first electrode 140 and the conductive wiring 200 will be described in more detail.

FIG. 4 is a diagram for explaining the first portion P1 included in the plurality of first electrodes 140 illustrated in FIG. 3 , and FIG. 5 is a diagram illustrating the first portion P1 of the first electrode 140 . It is a diagram for explaining a structure in which the conductive wiring 200 is connected.

Here, FIG. 4A is a plan view illustrating a pattern of a plurality of first electrodes 140 provided on the front surface of the semiconductor substrate 110 , and FIG. 4B is a diagram CS3 in FIG. 4A . -CS3 is a cross-section taken along the line, and FIG. 5 (a) is a plan view illustrating a structure in which a plurality of conductive wires 200 are connected to the front surface of the semiconductor substrate 110, and FIG. 5 (b) is Fig. 5 (a) shows a cross-section taken along line CS4-CS4, and Fig. 5 (c) shows a cross-section taken along line CS5-CS5 in Fig. 5 (a).

One example of the solar cell module according to the present invention is a first portion P1 that is cut off at an intersection where at least one first electrode 140 of a plurality of first electrodes 140 intersects a plurality of conductive wires 200 . may include

That is, only some of the first electrodes 140 among all of the plurality of first electrodes 140 have the first portion P1 at the intersection or, as shown in FIG. 4 , all of the first electrodes 140 at the intersection. A first portion P1 may be provided.

Here, in the first part P1 , the first electrode 140 is cut off as shown in FIG. 4A , and the first electrode 140 is not formed as shown in FIG. 4B , so the emitter part 120 ) may be covered with an anti-reflection film 130 .

In addition, as shown in FIG. 5 , a plurality of conductive wirings 200 may be connected to cross the first portion P1 of the first electrode 140 .

In this case, a portion of the conductive wiring 200 may be buried in the first portion P1 provided in the at least one first electrode 140 .

That is, as shown in (b) of FIG. 5 , a portion of the conductive wiring 200 at the intersection is located in the space between both sides of the at least one first electrode 140 exposed to the first portion P1. can

At this time, at the intersection, the conductive wiring 200 includes tin on both sides and the top surface of the at least one first electrode 140 exposed to the first portion P1 as shown in FIG. 5B . It can be connected through the conductive adhesive 251.

For example, the conductive adhesive 251 may include at least one of SnPb, SnPbAc, SnAgCu, and SnAg.

Accordingly, both side surfaces of the conductive wiring 200 can be connected to both sides and the upper surface of the first electrode 140 exposed to the first portion P1, so that the physical adhesion of the conductive wiring 200 can be improved by increasing the contact area. can be further improved.

In this case, when the conductive wiring 200 is connected to both side surfaces of the first electrode 140 exposed to the first portion P1 , an inter-metallic alloy is formed to form an inter-metallic alloy, thereby physically forming the conductive wiring 200 . Adhesion can be further improved.

In addition, since the first electrode 140 is not formed in the first portion P1 , the material cost for forming the first electrode 140 can be reduced, and the overall formation area of the first electrode 140 is relatively reduced. Accordingly, the open circuit voltage Voc may increase.

At this time, as shown in (b) of FIG. 5 , the gap H200 between a portion of the conductive wiring 200 and the anti-reflection film 130 at the intersection is the first electrode 140 passing through the anti-reflection film 130 . It may be smaller than the protruding height H140.

In addition, the interval H200 between a portion of the conductive wiring 200 and the anti-reflection film 130 at the intersection point and the interval between a portion of the conductive wiring 200 and the anti-reflection film 130 at the remaining portion excluding the intersection may be the same. can

Accordingly, as shown in (c) of FIG. 5 , the gap H200 between a portion of the conductive wiring 200 and the anti-reflection film 130 in the remaining portion except for the crossing point is also the first electrode 140 is formed by the anti-reflection film ( 130) and may be smaller than the protruding height H140.

For example, the protrusion height H140 at which the first electrode 140 protrudes through the anti-reflection layer 130 is between 10 μm and 30 μm, and the gap between a portion of the conductive wiring 200 and the anti-reflection layer 130 ( H200 may be less than or equal to 20 μm in a range smaller than the protrusion height H140 of the first electrode 140 .

In addition, as shown in (b) of FIG. 5 , the first gap D140 between both sides of the at least one first electrode 140 exposed to the first portion P1 at the intersection is the conductive wiring 200 . may be smaller than the line width W200 of

For example, the line width W200 of the conductive wiring 200 is between 250 μm and 350 μm, and the first gap D140 is formed between 200 μm and 280 μm in a range smaller than the line width W200 of the conductive wiring 200 . can be

Here, the conductive wiring 200 may include a core 201 made of a conductive material such as silver or copper, and a coating layer 202 that coats the surface of the core 201 and includes tin.

Here, the coating layer 202 may be composed of, for example, at least one of SnPb, SnPbAc, SnAgCu, and SnAg.

The coating layer 202 forms an inter-metallic alloy with both sides of the first electrode 140 exposed to the first portion P1 , thereby further improving the physical adhesion of the conductive wiring 200 . can do it

Here, the diameter of the core 201 may be between 200 μm and 310 μm, and the thickness of the coating layer 202 may be between 10 μm and 20 μm.

At this time, as shown in FIG. 5B , the core 201 of the conductive wiring 200 may be buried in the first portion P1 of the first electrode 140 .

As described above, when the conductive wiring 200 is buried in the disconnected first portion P1 of the first electrode 140 , the contact force of the conductive wiring 200 is strengthened as well as the conductive wiring 200 . Corrosion is also relatively reduced, and the reliability of a solar cell module can also be improved more.

6 is a view for explaining the present invention and another comparative example, and FIG. 7 is a view showing a partial appearance when the solar cell module according to the present invention is laminated.

As shown in the comparative example of FIG. 6 , there is no break in the first electrode 140 , and at the intersection of the first electrode 140 crossing the conductive wiring 200 , as shown in FIG. 6 ( b ), When the first electrode 140 and the conductive wire 200 are connected to each other, in the remaining portion except for the intersection of the conductive wire 200 and the first electrode 140 , the gap between the conductive wire 200 and the semiconductor substrate 110 is The separation interval H200 ′ may be relatively large.

That is, the gap H200 ′ between the conductive wiring 200 and the anti-reflection layer 130 may be equal to or greater than the height H140 ′ at which the first electrode 140 protrudes through the anti-reflection layer 130 .

In this case, in the lamination process, the first filling sheet 30a may not sufficiently fill the space between the conductive wiring 200 and the anti-reflection film 130 , and in this case, the conductive wiring 200 and the anti-reflection film 130 . ), an empty space ES filled with air may be formed.

This empty space ES may be filled with moisture condensed during operation of the solar cell module in a field, and such condensed moisture may corrode the conductive wiring 200, thereby reducing the reliability of the solar cell module. can

However, in the case of the present invention, the first electrode 140 has the first portion P1 cut off at the crossing point, and the conductive wiring 200 is buried in the first portion P1 of the first electrode 140 . When connected, the spacing H200 between a portion of the conductive wiring 200 and the semiconductor substrate 110 (or the anti-reflection layer 130 ) in the remaining portion except for the crossing point may be relatively small.

Therefore, after the lamination process is performed in the solar cell module manufacturing process, as shown in FIG. 7 , the first filling sheet 30a is formed with a portion of the conductive wiring 200 and the semiconductor substrate 110 at the remaining portions except for the intersection point. The space H200 spaced apart between (or the anti-reflection layer 130 ) may be sufficiently filled.

Accordingly, the solar cell module according to the present invention can further improve the reliability of the solar cell module.

8 is a view for explaining another example of the first portion P1 included in the first electrode 140 in the solar cell module according to the present invention.

In the previous embodiment, as an example, the first portion P1 is formed at the intersection of the first electrodes 140 , and the inclination angles of both sides of the first electrode 140 exposed to the first portion P1 are almost vertical. shown.

However, the inclination angle of both sides of the first electrode 140 exposed to the first portion P1 may be oblique as shown in FIG. 8 .

In this case, the gap H200 between the conductive wire 200 and the semiconductor substrate 110 or the gap H200 between the conductive wire 200 and the anti-reflection film 130 can be further reduced, and the conductive wire 200 is substantially The anti-reflection film 130 may be almost attached to the surface of the semiconductor substrate 110 on which it is formed.

So far, the case in which the entire plurality of first electrodes 140 includes the first portion P1 cut off at the intersection point has been described as an example, but the first portion P1 in which the entire plurality of first electrodes 140 are all cut off at the intersection point P1 has been described as an example. ), the present invention is not limited thereto, and only a portion of the entire plurality of first electrodes 140 may include the first portion P1 . This will be described in more detail as follows.

FIG. 9 is a road for explaining a solar cell module according to another example of the present invention, illustrating a case in which only some of the first electrodes 140 among all of the plurality of first electrodes 140 include the first portion P1. It is a way to do

Here, FIG. 9(a) is a schematic view of the front surface of the semiconductor substrate 110 to which the conductive wiring 200 is connected, and FIG. 9(b) is the semiconductor substrate shown in FIG. 9(a) (a). 110) is an enlarged view of some edge portions of the semiconductor substrate 110 adjacent to the end of the conductive wiring 200, and FIG. 9(c) shows the semiconductor substrate 110 shown in FIG. 9(a). The central part is enlarged.

In the solar cell module according to another example of the present invention, as shown in FIGS. 144 ) and a guide part 143 .

Here, the plurality of first electrodes 140 are formed to extend long in the first direction (x) on the front surface of the semiconductor substrate 110 , and the connection electrode 142 is formed on the front surface of the semiconductor substrate 110 in the second direction (y). ), and may be connected to some of the plurality of first electrodes 140 to cross over the entire first electrode 140 .

In addition, the pad part 144 may be formed at at least a part of the intersection point where the conductive wire 200 and the first electrode 140 intersect, and has a width W144 greater than the line width W142 of the connection electrode 142 . can be formed.

In addition, the guide part 143 may protrude long in the second direction (y) at the intersection of the first electrode 140 positioned at the outermost of the plurality of first electrodes 140 .

Among the plurality of first electrodes 140 , some edge first electrodes 140 positioned at the edge of the semiconductor substrate 110 in the second direction may include the first portion P1 at the intersection point. there is.

For example, some of the first electrodes 140 (ie, intersecting the conductive wiring 200 ) located at the edge where the end of the conductive wiring 200 is located among the semiconductor substrate 110 shown in FIG. 9A . The outermost two first electrodes 140] may include a first portion P1 in which the first electrode 140 is not formed at the crossing point.

In FIG. 9 , a case in which there are two first electrodes 140 including the first portion P1 is illustrated as an example, but the number of some edge first electrodes 140 including the first portion P1 is 1 It can be between five and five.

In addition, the remaining first electrodes 140 excluding some of the edge first electrodes 140 may not include the first portion P1 at the crossing point.

That is, in the edge portion of the semiconductor substrate 110 , except for the first electrode 140 having the first portion P1 , the remaining first electrodes 140 do not include the first portion P1 , and do not include the crossing point. A connection electrode 142 may be formed there.

Accordingly, the connection electrodes 142 are formed to extend elongated in the second direction y at the intersection, so that the remaining first electrodes 140 may be connected to each other by the connection electrodes 142 .

Since the connection electrodes 142 are located at a portion overlapping the conductive wirings 200 , unlike that illustrated in FIG. 6 , the connection electrodes 142 are conductive at portions other than the intersections of the first electrodes 140 and the conductive wirings 200 . The empty space ES may not be formed under the wiring 200 .

In addition, as shown in FIG. 9(b) , the guide part 143 includes a first portion P1 of the outermost first electrode 140 positioned at the outermost part among the first electrodes 140 on the edge. It may protrude long in the second direction (y) from both ends.

Here, the outermost first electrode 140 may refer to the first electrode 140 that finally crosses the conductive wiring 200 that is disposed long in the second direction (y).

As described above, the distance D143 between the guide portions 143 provided at both ends of the first portion P1 of the outermost first electrode 140 may be smaller than the line width W200 of the conductive wiring 200 .

Accordingly, when the end of the conductive wiring 200 is positioned on the front surface of the semiconductor substrate 110, the end of the conductive wiring 200 is prevented from being bent, so that the exterior of the module can be seen more elegantly.

In addition, the pad part 144 may be positioned at at least some of the plurality of crossing points positioned on the remaining first electrodes 140 to increase a connection area with the conductive wiring 200 .

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the right.

Claims (19)

a plurality of solar cells each having a semiconductor substrate, a plurality of first electrodes elongated in a first direction on a front surface of the semiconductor substrate, and a second electrode on a rear surface of the semiconductor substrate; and
It is connected to a first electrode of a first solar cell among the plurality of solar cells and a second electrode of a second solar cell adjacent to the first solar cell, and is disposed in a second direction crossing the first direction to cross the plurality of solar cells. a plurality of conductive wires electrically connecting the solar cells;
At least one first electrode of the plurality of first electrodes includes a first portion that is cut off at an intersection point crossing the plurality of conductive wires,
A portion of the conductive wiring is buried in the first portion provided in the at least one first electrode,
A first interval between both side surfaces of the at least one first electrode exposed to the first portion at the crossing point is smaller than a line width of the conductive line. According to claim 1,
A part of the conductive wiring at the intersection is located in a space between both side surfaces of the at least one first electrode exposed to the first part. According to claim 1,
An anti-reflection film made of a dielectric material is further formed on the front surface of the semiconductor substrate,
Each of the plurality of first electrodes is connected to the front surface of the semiconductor substrate through the anti-reflection film,
A distance between a portion of the conductive wiring and the anti-reflection film at the intersection is smaller than a height at which the first electrode protrudes through the anti-reflection film. 4. The method of claim 3,
At the intersection, the conductive wiring is connected to a side surface and an upper surface of the at least one first electrode exposed to the first portion through a conductive adhesive. 4. The method of claim 3,
A distance between a portion of the conductive wiring and the anti-reflection film in the remaining portion except for the crossing point is smaller than a height at which the first electrode protrudes through the anti-reflection film. According to claim 1,
The entirety of the plurality of first electrodes is a solar cell module including the first portion at the intersection. delete According to claim 1,
The first interval is 5% to 80% or less of the line width of the conductive wiring solar cell module. According to claim 1,
A line width of the conductive wiring is between 250 μm and 350 μm, and the first interval is between 200 μm and 280 μm in a range smaller than the line width of the conductive wiring. According to claim 1,
The conductive wiring is a solar cell module including a core made of a conductive material and a coating layer coating the surface of the core and containing tin. 11. The method of claim 10,
A solar cell module in which the core of the conductive wiring is buried in the first portion. 12. The method of claim 11,
The diameter of the core is between 200㎛ ~ 310㎛, the thickness of the coating layer is between 10㎛ ~ 20㎛ solar cell module. 4. The method of claim 3,
The protrusion height at which the first electrode protrudes through the anti-reflection film is between 10 μm and 30 μm,
A distance between a portion of the conductive wiring and the anti-reflection film is 20 μm or less in a range smaller than the protrusion height. According to claim 1,
A partial edge first electrode positioned at an edge of the semiconductor substrate in a second direction among the plurality of first electrodes includes the first portion at the intersection,
A solar cell module in which the remaining first electrodes except for the some edge first electrodes do not include the first portion at the crossing point. 15. The method of claim 14,
A solar cell module in which the number of the first partial edge electrodes having the first portion is between 1 and 5. 15. The method of claim 14,
Both ends of the first portion of the outermost first electrode positioned at the outermost among the partial first electrodes further include a guide portion protruding in the second direction. 17. The method of claim 16,
A distance between the guide portions provided at both ends of the first portion of the outermost first electrode is smaller than a line width of the conductive wiring module. 15. The method of claim 14,
and a connection electrode formed at the intersection of the remaining first electrodes and extending in the second direction to connect the remaining first electrodes to each other. 19. The method of claim 18,
A solar cell module in which a pad portion having a width greater than a line width of the first electrode or a line width of the connection electrode is positioned at at least some of the intersection points of the remaining first electrodes.

Images