KR102162719B1 - Solar cell module - Google Patents

Abstract

The solar cell module according to an embodiment of the present invention includes first to fourth pads for first electrodes positioned on the rear surface of the semiconductor substrate, and first to fourth pads positioned on the rear surface of the semiconductor substrate. A first rear junction solar cell and a second rear junction solar cell each including a first to fourth pad for second electrode; And an interconnector electrically connecting the first rear junction solar cell and the second rear junction solar cell, wherein the interconnector comprises a bridge portion positioned in a space between the first and second rear junction solar cells, And first to fourth tab portions each protruding from the bridge portion toward the first electrode pad of the first rear junction solar cell and the second electrode pad of the second rear junction solar cell. And the first to fourth tab portions are bonded to the first electrode pad of the first rear bonded solar cell and the second electrode pad of the second rear bonded solar cell, respectively.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module having a plurality of interdigitated back contact (IBC) solar cells.

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

A typical solar cell includes a substrate and an emitter layer each 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.

When light is incident on such a solar cell, electrons inside the semiconductor become free electrons (hereinafter referred to as'electrons') due to the photoelectric effect, and electrons and holes are n according to the principle of pn junction. It moves toward the emitter part and the substrate, respectively, toward the p-type semiconductor and the p-type semiconductor. And the moved electrons and holes are collected by respective electrodes electrically connected to the substrate and the emitter.

On the other hand, in recent years, interdigitated back contact solar cells that improve the efficiency of solar cells by increasing the light-receiving area by forming the electronic collector and the hole collector on the rear surface of the substrate, that is, the rear surface where light does not enter, have been developed. Is being developed.

The technical problem to be achieved by the present invention is to provide a solar cell module capable of suppressing the occurrence of current loss and obtaining high output.

The solar cell module according to an embodiment of the present invention includes first to fourth pads for first electrodes positioned on the rear surface of the semiconductor substrate, and first to fourth pads positioned on the rear surface of the semiconductor substrate. A first rear junction solar cell and a second rear junction solar cell each including a first to fourth pad for second electrode; And an interconnector electrically connecting the first rear junction solar cell and the second rear junction solar cell, wherein the interconnector comprises a bridge portion positioned in a space between the first and second rear junction solar cells, And first to fourth tab portions each protruding from the bridge portion toward the first electrode pad of the first rear junction solar cell and the second electrode pad of the second rear junction solar cell. The first to fourth tab portions are bonded to the first electrode pad of the first rear bonding solar cell and the second electrode pad of the second rear bonding solar cell, respectively.

A coating layer including a tin-based solder may be positioned on at least one side of the conductive metal.

The solar cell module is disposed between a light-transmitting front substrate positioned on the front surface side of a rear junction solar cell, a rear substrate positioned on the back surface side of a rear junction solar cell, and between the front substrate and the rear substrate. It may further include a sealing material for sealing the plurality of rear junction solar cells.

In addition, the first electrode pads and the second electrode pads may be composed of 5 to 100, respectively, and the interconnector may include the same number of tabs as the number of the first electrode pads and the second electrode pads. I can.

In this case, the number of pads for the first electrode and the number of pads for the second electrode may increase as the size of the semiconductor substrate increases and as the required output of the solar cell increases.

For example, a semiconductor substrate having a size of 3 inches may include four pads for first electrodes and four pads for second electrodes, and a semiconductor substrate having a size of 4 inches includes six first electrodes. A pad and six pads for second electrodes may be provided, and a semiconductor substrate having a size of 5 inches may be provided with eight pads for first electrodes and eight pads for second electrodes.

However, the number of pads for the first electrode and the pads for the second electrode can be variously changed within the range of 4 to 100 depending on the size of the semiconductor substrate or the required size of the output of the solar cell.

The first electrode pads may be positioned on the first edge of the rear surface of the semiconductor substrate, and the second electrode pads may be positioned on the second edge of the rear surface of the semiconductor substrate facing the first edge.

In contrast, the first electrode pads may be positioned at the first edge and the second edge of the rear surface of the semiconductor substrate, and the second electrode pads may be positioned at the center of the rear surface of the semiconductor substrate.

The rear junction solar cell includes: a plurality of first electrodes positioned on the rear surface of the semiconductor substrate and extending to be perpendicular to the first edge and the second edge; And a plurality of second electrodes alternately positioned with the first electrodes on the rear surface of the semiconductor substrate along the length directions of the first and second edges and extending in the same direction as the plurality of first electrodes.

In addition, the rear junction solar cell includes: a first current collecting electrode for a first electrode extending along a length direction of a first edge and a second edge and connecting ends of the plurality of first electrodes from the first edge side; And a current collecting electrode for a second electrode extending in the same direction as the current collecting electrode for the first electrode and connecting ends of the plurality of second electrodes from the second edge side.

The first electrode pads may be electrically and physically connected to the first electrode current collecting electrode, and the second electrode pads may be electrically and physically connected to the second electrode current collecting electrode.

The spacing between the electrode pads of the same polarity may be formed from 1 mm to 80 mm, and the spacing between the electrode pads of the same polarity may increase or decrease in inverse proportion to the number of electrode pads of the same polarity. .

The first electrode pads and the second electrode pads may have a plan area of 1 mm 2 to 780 mm 2, respectively, and the plan area of each of the first electrode pads and the plan area of each of the second electrode pads have the same polarity. It may increase or decrease in proportion to the spacing between the electrode pads.

The first electrode pads may be positioned at the same distance from the first edge, and the second electrode pads may be positioned at the same distance from the second edge.

A solar cell module equipped with a rear junction solar cell having the characteristics of this configuration is suitable for adjusting the size and number of electrode pads of the rear junction solar cell according to the size of the semiconductor substrate or the size of the required output, It is possible to improve the output of the solar cell module by reducing the loss that occurs when current is transferred between the cells.

1 is a plan view schematically showing a rear surface of a rear junction solar cell according to a first embodiment of the present invention.
2 is a partial cross-sectional view of FIG. 1 in the second direction.
3 is a cross-sectional view of a main part of a solar cell module having a rear junction solar cell shown in FIG. 1.
4 is a plan view according to an embodiment of the interconnector used in the solar cell module of FIG. 3.
5 is a graph showing experimental results of Joule loss according to the number of electrode pads.
6 is a plan view schematically showing a rear surface of a rear junction solar cell according to a second embodiment of the present invention.
7 is a plan view schematically showing a rear surface of a rear junction solar cell according to a third embodiment of the present invention.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. This is not intended to limit the present invention to a specific embodiment, it can be understood to include all changes, equivalents, or substitutes included in the spirit and scope of the present invention.

In describing the present invention, terms such as first and second may be used to describe various components, but the components may not be limited by the terms. These terms may be used only for the purpose of distinguishing one component from another component.

For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

The term “and/or” may include a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "coupled" to another component, it is said that it may be directly connected or coupled to the other component, but other components may exist in the middle. Can be understood.

On the other hand, when a component is referred to as being "directly connected" or "directly coupled" to another component, it may be understood that there is no other component in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions may include plural expressions unless the context clearly indicates otherwise.

In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, and one or more other features It may be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

In the drawings, the thicknesses are enlarged to clearly express various layers and regions. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where the other part is "directly above", but also the case where the other part is in the middle. Conversely, when one part is "directly above" another part, it means that there is no other part in the middle.

Unless otherwise defined, all terms, including technical or scientific terms, used herein may have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

Terms as defined in a commonly used dictionary may be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in this application, interpreted as an ideal or excessively formal meaning. May not be.

In addition, the following embodiments are provided to more completely explain to those with average knowledge in the art, and the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Then, the present invention will be described with reference to the accompanying drawings.

In the following embodiments, the first electrode, the second electrode having the opposite polarity of the first electrode, the first electrode current collector, and the second electrode current collector are all described for a rear junction solar cell located on the rear surface of the semiconductor substrate. In the present invention, the second electrode (or first electrode) is located on the front surface of the semiconductor substrate, and the first electrode (or second electrode), the current collector for the first electrode, and the current collector for the second electrode are located on the rear surface of the semiconductor substrate. It can also be applied to solar cells of MWT (Metal Wrap Through) structure.

Hereinafter, a rear junction solar cell according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

1 is a view schematically showing a rear surface of a rear junction solar cell, and FIG. 2 is a partial cross-sectional view of FIG. 1 in a second direction.

Referring to the drawings, the rear junction solar cell 100 includes a semiconductor substrate 110 of a first conductivity type, a light-receiving surface of the semiconductor substrate 110, for example, a front dielectric layer 120 formed on a front surface, and a front dielectric layer. The antireflection film 130 formed on the 120, the first doped portion 141 formed on the other surface of the semiconductor substrate 110, that is, the back surface, and doped with impurities of the first conductivity type at a high concentration, 1 A second doped portion 142 formed on the rear surface of the semiconductor substrate 110 at a position adjacent to the doped portion 141 and doped with a high concentration of impurities of a second conductivity type opposite to the first conductivity type, and a first doped portion A plurality of electron electrodes 160 electrically connected to the rear dielectric layer 150 exposing a portion of the 141 and the second doped portion 142, and the first doped portion 141 exposed by the rear dielectric layer 150 , Hereinafter, referred to as'first electrode'), a plurality of hole electrodes 170 electrically connected to the second doped portion 142 exposed by the rear dielectric layer 150, hereinafter referred to as'second electrode' ), a plurality of electronic pads 160b (hereinafter, referred to as'first electrode pads') located on the first edge E1 of the rear surface of the semiconductor substrate 110, and the first of the rear surface of the semiconductor substrate 110 It includes a plurality of hole pads 170b (hereinafter, referred to as “second electrode pads”) positioned on the second edge E2 side facing the edge E1.

Here, the first edge E1 of the semiconductor substrate 110 refers to an edge positioned on the left side in the first direction X-X′ in FIG. 1, and the second edge E2 is the first direction X- X') refers to the corner located on the right.

Accordingly, the first edge E1 and the second edge E2 are formed to be elongated in a second direction Y-Y' orthogonal to the first direction X-X', respectively.

The plurality of first electrodes 160 extend in a direction orthogonal to the first edge E1 and the second edge E2 of the semiconductor substrate 110, that is, in a first direction X-X'. The second electrode 170 alternately with the first electrode 160 along the length direction (Y-Y') of the first edge (E1) and the second edge (E2), that is, the second direction (Y-Y'). It is positioned and extends in the same direction as the plurality of first electrodes 160, that is, in the first direction X-X'.

And left ends of the plurality of first electrodes 160 are electrically connected to the first electrode pad 160b from the first edge E1 side, and the right ends of the plurality of second electrodes 170 are the second edges ( E1) is electrically connected to the second electrode pad 170b.

The light receiving surface of the semiconductor substrate 110 may be formed as a texturing surface having a plurality of irregularities 111. In this case, the front dielectric layer 120 and the antireflection layer 130 are also formed as texturing surfaces.

The semiconductor substrate 110 is made of a first conductivity type, for example, n-type monocrystalline silicon. However, unlike this, the semiconductor substrate 110 may have a p-type conductivity type and may be made of polycrystalline silicon. In addition, the semiconductor substrate 110 may be made of a semiconductor material other than silicon.

Since the light-receiving surface of the semiconductor substrate 110 is formed as a texturing surface having a plurality of irregularities 111, the absorption rate of light is increased, thereby improving the efficiency of the solar cell.

The front dielectric layer 120 formed on the light-receiving surface of the semiconductor substrate 110 having a plurality of irregularities 111 formed thereon contains impurities of pentavalent elements such as phosphorus (P), arsenic (As), and antimony (Sb). ) May be a doped film with a higher concentration, and may act as a front surface field (FSF) similar to a back surface field (BSF). Accordingly, electrons and holes separated by the incident light are prevented from being recombined on the light-receiving surface of the semiconductor substrate 110 and disappearing.

The antireflection film 130 formed on the surface of the front dielectric layer 120 is made of a silicon nitride film (SiNx) or a silicon oxide film (SiO ₂ ). The antireflection film 130 reduces the reflectivity of incident sunlight and increases selectivity in a specific wavelength region, thereby increasing the efficiency of the solar cell.

The plurality of first doped portions 141 formed on the rear surface of the semiconductor substrate 110 are doped with an n-type impurity higher than that of the semiconductor substrate 110, and the plurality of second doped portions 142 contain p-type impurities. It is highly doped. Accordingly, the second doped portion 142 forms a p-n junction with the n-type semiconductor substrate 110.

The first doped portion 141 and the second doped portion 142 act as a passage for carriers (electrons and holes).

The rear dielectric layer 150 exposing a portion of the first doped portion 141 and the second doped portion 142 may be formed of a silicon oxide layer (SiO ₂ ), a silicon nitride layer (SiNx), or a combination thereof.

The rear dielectric layer 150 may act as a BSF that prevents carriers separated into electrons and holes from being recombined and reflects the incident light into the solar cell so as not to be lost to the outside, thereby reducing the amount of light lost to the outside.

The rear dielectric layer 150 may be formed as a single layer, but may have a multilayer structure such as a double layer or a triple layer.

A first electrode 160 is formed on the first doped portion 141 that is not covered by the rear dielectric layer 150 and the rear dielectric layer 150 adjacent to the first doped portion 141, and is formed as the rear dielectric layer 150. A second electrode 170 is formed on the uncovered second doped portion 142 and the portion of the rear dielectric layer 150 adjacent to the second doped portion 142.

In addition, first to fourth first electrode pads 160b electrically connected to the plurality of first electrodes are formed on the side of the first edge E1 located on the left side of FIG. 1 of the rear surface of the semiconductor substrate 110 The first to fourth second electrode pads 170b electrically connected to the plurality of second electrodes 170 are formed on the side of the second edge E2 positioned on the right side of FIG. 1. The fourth first electrode pad 160b is electrically and physically connected to the first current collecting electrode 160a extending in the second direction (Y-Y'), and the first to fourth second electrodes The pad 170b is electrically and physically connected to the current collecting electrode 170a for the second electrode extending in the second direction.

Here, the pads 160b and 170b refer to portions having a larger area, greater thickness, or excellent conductivity than the electrodes 160, 160a, 170, and 170a.

As described above, since the pads 160b and 170b are formed in a larger area, thicker, or formed of a material having excellent conductivity compared to the electrodes 160, 160a, 170, 160a, the pads 160b and 170b are formed of an electrode ( 160, 160a, 170, 160a) has a smaller sheet resistance.

Accordingly, the tab portion of the interconnector can be stably bonded to the pad of the solar cell, and current generated from the solar cell can be satisfactorily transferred to the interconnector.

In the rear junction solar cell having such a configuration, the first to fourth first electrode pads 160b and the first to fourth second electrode pads 170b have the following characteristics.

Specifically, the first electrode pad 160b and the second electrode pad 170b are provided in various numbers within the range of 4 to 100 depending on the size of the semiconductor substrate 110, and the semiconductor substrate The larger the size of and the larger the required output size, the greater the number of pads.

As an example, the rear junction solar cell 100 of this embodiment has a semiconductor substrate 110 having a size of 3 inches, and the rear surface of the semiconductor substrate 110 is for first to fourth first electrodes. The pad 160b and the first to fourth second electrode pads 170b are positioned.

The first to fourth first electrode pads 160b are positioned at the same distance D1 from the first edge E1, and the first to fourth second electrode pads 170b are They are positioned at the same distance D2 from the edge E2.

In this case, the distance D1 between the first edge E1 and the first electrode pad 160b and the distance D2 between the second edge E2 and the second electrode pad 170b may be the same. However, they may be different.

In addition, the spacing (D3) between electrode pads of the same polarity can be variously changed within the range of 1 mm to 80 mm, and the spacing (D3) between electrode pads of the same polarity is used for electrodes of the same polarity. It can increase or decrease in inverse proportion to the number of pads.

For example, as the number of electrode pads of the same polarity increases, the spacing (D3) between electrode pads of the same polarity decreases, and on the contrary, as the number of electrode pads of the same polarity decreases, the electrode pads of the same polarity The interspace D3 increases.

In addition, the first electrode pad 160b and the second electrode pad 170b may be variously formed within a range of 1 mm 2 to 780 mm 2, and the plan area of the first electrode pad 160 b and the second electrode pad 160 b The planar area of the electrode pad 170b may increase or decrease in proportion to the spacing D3 between electrode pads of the same polarity.

For example, when the spacing D3 between electrode pads of the same polarity increases, the planar area of the pads increases, and when the spacing D3 between electrode pads of the same polarity decreases, the planar area of the pads decreases.

Similarly, the planar area of the first electrode pad 160b and the planar area of the second electrode pad 170b may increase or decrease in inverse proportion to the number of pads.

For example, when the number of pads increases, the planar area of each pad decreases, and when the number of pads decreases, the planar area of each pad increases.

However, the planar area of the pads may be formed to have a constant size regardless of the number of pads and the spacing between pads of the same polarity.

As shown in FIG. 5, the rear junction solar cell of this configuration has reduced Joule loss by about 70% compared to the case where three pads for the first electrode and three pads for the second electrode are each provided. have.

Here, when the joule loss is reduced by about 70%, the relative loss is reduced by about 70%, and when the joule loss when three pads for a first electrode and three pads for a second electrode are provided is 100%, This means that the joule loss occurs about 70% in the rear junction solar cell provided with four first and second electrode pads, respectively.

Accordingly, the loss generated when current is transferred between neighboring solar cells is reduced compared to the prior art, and thus the output of a solar cell module including a plurality of rear junction solar cells is improved.

In the above, the first electrode pad 160b is located on the first edge (E1) side of the semiconductor substrate 110, and the second electrode pad 170b is located on the second edge (E2) side of the semiconductor substrate 110. Although described as an example, at least one of the first electrode pad 160b and the second electrode pad 170b may be located in the center of the inner region of the semiconductor substrate.

For example, the first electrode pad 160b may be positioned at the first edge E1 and the second edge E2 of the rear surface of the semiconductor substrate 110, respectively, and the second electrode pad 170b is a semiconductor It may be located in the center of the rear surface of the substrate 110.

Hereinafter, a solar cell module including a rear junction solar cell according to a first embodiment of the present invention will be described with reference to FIGS. 3 and 4.

3 is a cross-sectional view of a main part of the solar cell module, and FIG. 4 is a plan view according to an embodiment of an interconnector used in the solar cell module of FIG. 3.

The solar cell module having a plurality of rear junction solar cells described above includes an interconnector 200 for electrically connecting two adjacent rear junction solar cells, a sealing material 300 for sealing the rear junction solar cells, and light. It includes a transmissive front substrate 310 and a rear sheet 320.

Hereinafter, one of the two adjacent rear junction solar cells is referred to as a first solar cell 100A, and the other solar cell is referred to as a second solar cell 100B.

The interconnector 200 is used to connect the second electrode pads 170b of the first solar cell 100A adjacent to each other to the first electrode pads 160b of the second solar cell 100B.

The interconnector 200 includes a conductive metal 210, and a coating layer 260 including a tin (Sn)-based solder may be formed on at least a front surface of the conductive metal 210 . For example, the coating layer 260 may be located on the front, rear, and side surfaces of the conductive metal 210.

The conductive metal 210 of the interconnector 200 is positioned at regular intervals in a second direction (Y-Y') orthogonal to the first direction (X-X'), and the corresponding pad of the rear junction solar cell 100 In the second direction (Y-Y') to connect the four tap portions 220 joined to the (160b, 170b) and the four tap portions 220 spaced apart in the second direction (Y-Y'). It extends and includes a bridge portion 230 located in a space between the first rear junction solar cell and the second rear junction solar cell.

As shown in FIG. 4, the four tab portions provided on the conductive metal 210 of the interconnector 200 are first located at both ends of the conductive metal 210 in the second direction (Y-Y'). The tab portion 220-1 and the second tab portion 220-2, and the third tab portion 220-3 and the fourth tab positioned between the first tab portion 220-1 and the second tab portion 220-2 The tab portion 220-4 is included, and each tab portion may be bonded to the corresponding pad by an adhesive 250 formed of a tin (Sn)-based solder paste or a silver (Ag)-based conductive paste.

In this case, the intervals between the tab portions may be formed equal to each other, but differently, the interval between the tab portions may be formed differently.

And the conductive metal 210 may be formed with a slit 240 or a slot for absorbing the thermal stress applied to the interconnector 200, as shown by the dotted line, the slit 240 or the slot is formed in various shapes. Can be.

On the other hand, the front substrate 310 may be formed of low iron tempered glass, and the rear sheet 320 may include TPT (Tedlar/PET/Tedlar), TPE (Tedlar/PET/EVA), TAT ( TAT; Tedlar/Al foil/Tedlar), TPAT (Tedlar/PET/Al foil/Tedalr), TPOT; Tedlar/PET/Oxide/Tedlar), PAP; PEN/Al foil/ PET) or PET (Polyester) may be formed.

Hereinafter, a rear junction solar cell according to another embodiment of the present invention will be described with reference to FIGS. 6 and 7.

The rear junction solar cell shown in FIG. 6 includes a semiconductor substrate 100' that is 1 inch larger in size than the rear junction solar cell shown in FIG. 1, and the rear junction solar cell shown in FIG. A semiconductor substrate 100" having a size of 2 inches increased compared to the rear junction solar cell shown in the embodiment is provided.

That is, the semiconductor substrate 110 ′ of the rear junction solar cell shown in FIG. 6 is formed in a size of 4 inches, and the semiconductor substrate 110 ″ of the rear junction solar cell shown in FIG. 7 is formed in a size of 5 inches. do.

In addition, the semiconductor substrate 110 ′ includes a larger number of first electrodes 160 and second electrodes 170 than the semiconductor substrate 110, and is used for a larger number of first electrodes than the semiconductor substrate 100. A pad 160b and a second electrode pad 170b are provided.

However, the number of the first electrodes 160 and the second electrodes 170 formed on the semiconductor substrate 110 ′ may be the same as in the first embodiment described above.

In addition, the semiconductor substrate 110 ″ includes a greater number of first electrodes 160 and second electrodes 170 than the semiconductor substrate 110 ′, and has a greater number of first electrodes than the semiconductor substrate 100 ′. A first electrode pad 160b and a second electrode pad 170b are provided.

However, the number of the first electrodes 160 and the second electrodes 170 formed on the semiconductor substrate 110 ″ may be the same as in the first embodiment described above.

For example, as shown, the semiconductor substrate 110 ′ may include first to sixth first electrode pads 160b and first to sixth second electrode pads 170b, The semiconductor substrate 110 ″ may include first to eighth first electrode pads 160b and first to eighth second electrode pads 170b.

However, the number of first electrode pads 160b and the number of second electrode pads 170b provided in each of the semiconductor substrates 110 ′ and 110 ″ may be variously changed within a range of 100 or less.

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 defined in the following claims are also provided. It belongs to the scope of rights.

100A: first solar cell 100B: second solar cell
160: first electrode 170: second electrode
160b: first electrode pad 170b: second electrode pad
200: interconnector

Claims (14)

First to fourth pads for first electrodes positioned on the rear surface of the semiconductor substrate, and first to fourth pads for second electrodes positioned on the rear surface of the semiconductor substrate. a first rear junction solar cell and a second rear junction solar cell each including a fourth pad for second electrode); And
Interconnector electrically connecting the first rear junction solar cell and the second rear junction solar cell
Including,
The first electrode pads are located at a first edge of the rear surface of the semiconductor substrate, and the second electrode pads are located at a second edge of the rear surface of the semiconductor substrate facing the first edge,
The first and second rear junction solar cells, respectively,
A plurality of first electrodes positioned on the rear surface of the semiconductor substrate and extending to be perpendicular to the first edge and the second edge;
A plurality of second electrodes alternately positioned with the first electrodes on the rear surface of the semiconductor substrate along the length directions of the first and second edges, and extending in the same direction as the plurality of first electrodes;
A current collecting electrode for a first electrode extending along a longitudinal direction of the first and second corners and connecting ends of the plurality of first electrodes from the first corner; And
A current collecting electrode for a second electrode extending in the same direction as the current collecting electrode for the first electrode and connecting ends of the plurality of second electrodes from the second edge side
Including more,
The distance between the first edge and the first edge-side end of the first electrode is smaller than the distance between the first edge and the first edge-side end of the second electrode,
The distance between the second edge and the second edge-side end of the second electrode is smaller than the distance between the second edge and the second edge-side end of the first electrode,
The first electrode pads are located in a region between the first current collecting electrode and the end of the second electrode at the first edge,
The second electrode pads are located in a region between the current collecting electrode for the second electrode and the end of the first electrode at the second edge side,
The interconnector includes a bridge portion positioned in a space between the first and second rear junction solar cells, and a first electrode pad of the first rear junction solar cell and the second rear junction solar cell. And a conductive metal including first to fourth tab portions protruding from the bridge portion toward the second electrode pad, respectively,
The first to fourth tab portions are bonded to the first electrode pad of the first rear bonded solar cell and the second electrode pad of the second rear bonded solar cell, respectively. In claim 1,
A solar cell module in which a coating layer including a tin-based solder is positioned on at least one side of the conductive metal. In claim 1,
A light-transmitting front substrate positioned on a front surface of the rear junction solar cell;
A rear substrate positioned on a back surface side of the rear junction solar cell; And
A sealing material disposed between the front substrate and the rear substrate and sealing the plurality of rear bonded solar cells
Solar cell module further comprising a. In claim 1,
Each of the first electrode pads and the second electrode pads is composed of 5 to 100, and the interconnector includes a number of tabs equal to the number of the first electrode pads and the second electrode pads. Solar cell module including. In claim 4,
The number of pads for the first electrode and the number of pads for the second electrode increase as the size of the semiconductor substrate increases. delete delete delete In claim 1,
The first electrode pads are electrically and physically connected to the first current collecting electrode and the first electrode, and the second electrode pads are electrically and physically connected to the second current collecting electrode and the second electrode. Solar cell modules connected to each other. In any one of claims 1 to 5 and 9,
A solar cell module in which the interval between the electrode pads of the same polarity is 1 mm to 80 mm. In claim 10,
A solar cell module in which an interval between the electrode pads of the same polarity increases or decreases in inverse proportion to the number of electrode pads of the same polarity. In claim 10,
A solar cell module in which the first electrode pads and the second electrode pads each have a plan area of 1 mm 2 to 780 mm 2. In claim 12,
A solar cell module in which a planar area of each of the first electrode pads and a planar area of each of the second electrode pads increases or decreases in proportion to a spacing between the electrode pads of the same polarity. In claim 13,
The first electrode pads are positioned at the same distance from the first edge, and the second electrode pads are positioned at the same distance from the second edge.

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