KR20190025099A - Solar cell and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a photovoltaic cell with increased productivity and a manufacturing method thereof. According to the present invention, the photovoltaic cell comprises: a first cell having a plurality of upper grooves on an upper surface thereof; a first cover sheet covering the upper surface of the first cell; a plurality of upper metal wires provided between the first cover sheet and the upper surface of the first cell and inserted into the first upper grooves; and a first upper conductive pattern provided on the upper surface of the first cell and connected to the first upper metal wires. The first upper grooves and the first upper metal wires may be extended along a first direction.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell and a manufacturing method thereof,

The present invention relates to a solar cell and a manufacturing method thereof.

Photovoltaic generation, which converts light energy into electrical energy using the photoelectric conversion effect, is widely used as means for obtaining pollution-free energy. With the improvement of the photoelectric conversion efficiency of the solar cell, a solar power generation system using a plurality of solar cell modules is also installed in a private house. A solar cell includes a semiconductor substrate having a p-n junction, and generates a current by using light incident on the semiconductor substrate.

The present invention is directed to a solar cell with improved productivity and a method of manufacturing the same.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

A solar cell according to the present invention includes: a first cell having a plurality of first upper grooves on an upper surface thereof; A first cover sheet covering an upper surface of the first cell; A plurality of first upper metal wires provided between the first cover sheet and the upper surface of the first cell, the first upper metal wires being inserted into the first upper grooves; And a first upper conductive pattern provided on an upper surface of the first cell and connected to the first upper metal wires, wherein the first upper grooves and the first upper metal wires extend along a first direction do.

A method of manufacturing a solar cell according to the present invention includes: forming a plurality of first finger grooves extending along a first direction on an upper surface of a cell substrate; Cutting the cell substrate on which the first finger grooves are formed to form a first cell having first top grooves and a second cell having second top grooves; Electrically connecting the first cell and the second cell; Forming a plurality of upper metal wires on the first cover sheet; And attaching the first cover sheet to the first cell and the second cell, and inserting the upper metal wires into the first upper grooves and the second upper grooves.

The details of other embodiments are included in the detailed description and drawings.

According to the embodiments of the present invention, the metal wires formed on the cover sheets can be connected to the cells to simplify the manufacturing process. Thus, the productivity of the solar cell can be improved.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

1 is a plan view of a solar cell module according to an embodiment of the present invention.
FIG. 2 is a bottom view of the solar cell module of FIG. 1. FIG.
3 is a cross-sectional view taken along line II 'of Fig.
4 is an enlarged view of the area A in Fig.
5 is a cross-sectional view taken along line II-II 'of FIG.
6 is an enlarged view of the area B in Fig.
7 is an enlarged view of the area C in Fig.
8 is a cross-sectional view illustrating a modification of the solar cell module according to an embodiment of the present invention.
FIGS. 9A to 9H are views for explaining manufacturing processes of the solar cell of FIG.
10A to 10E are views for explaining the manufacturing processes of the solar cell of FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Embodiments described herein will be described with reference to cross-sectional views and / or plan views that are ideal illustrations of the present invention. In the drawings, the thicknesses of the films and regions are exaggerated for an effective description of the technical content. Thus, the regions illustrated in the figures have schematic attributes, and the shapes of the regions illustrated in the figures are intended to illustrate specific types of regions of the elements and are not intended to limit the scope of the invention. Although the terms first, second, third, etc. in the various embodiments of the present disclosure are used to describe various components, these components should not be limited by these terms. These terms have only been used to distinguish one component from another. The embodiments described and exemplified herein also include their complementary embodiments.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises " and / or "comprising" when used in this specification is taken to specify the presence or absence of one or more other components, steps, operations and / Or additions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a concept of the present invention and embodiments according to the present invention will be described in detail with reference to the drawings.

1 is a plan view of a solar cell module according to an embodiment of the present invention. 2 is a bottom view of the solar cell module of FIG. 3 is a cross-sectional view taken along line I-I 'of FIG. 4 is an enlarged view of the area A in Fig.

1 to 4, a solar cell module 1 according to an embodiment of the present invention may include a solar cell 10 and an electronic device 20. [ The solar cell 10 may be a solar cell having a shingled structure. The solar cell 10 can convert light energy into electrical energy using a photovoltaic effect. The solar cell 10 includes a plurality of cells 100, upper electrode portions 210 and 220, lower electrode portions 230 and 240, a first cover sheet 300, and a second cover sheet 350 . The solar cell 10 may further include an electronic device 20 electrically connected to the plurality of cells 100.

The plurality of cells 100 may be arranged along the first direction D1. The details of the arrangement of the cells 100 will be described later. In an embodiment, each of the cells 100 may be provided in a generally rectangular shape having a minor axis in the first direction D1 and a major axis in the second direction D2 perpendicular to the first direction D1, It does not. In an embodiment, the cells 100 may include first through fourth cells 101, 102, 103, 104.

The cells 100 may include upper grooves UG and lower grooves LG. The upper grooves UG and the lower grooves LG can be vertically overlapped with each other.

In the embodiment, the upper grooves UG include first upper grooves UG1 provided on the upper surface of the first cell 101, second upper grooves UG2 provided on the upper surface of the second cell 102, Third upper grooves UG3 provided on the upper surface of the fourth cell 104 and fourth upper grooves UG4 provided on the upper surface of the fourth cell 104. [ The first to fourth upper grooves UG1, UG2, UG3, UG4 may extend in the first direction D1. Each of the first upper grooves UG1, each of the second upper grooves UG2, each of the third upper grooves UG3, and each of the fourth upper grooves UG4 are arranged along the second direction D2 (See FIG. 9C).

In the embodiment, the lower grooves LG include first lower grooves LG1 provided on the lower surface of the first cell 101, second lower grooves LG2 provided on the lower surface of the second cell 102, The third bottom grooves LG3 provided on the bottom surface of the first cell 104 and the fourth bottom grooves LG4 provided on the bottom surface of the fourth cell 104. [ The first to fourth lower grooves LG1, LG2, LG3, and LG4 may be elongated in the first direction D1. Each of the third lower grooves LG3 and each of the fourth lower grooves LG4 of each of the second lower grooves LG2 of each of the first lower grooves LG1 are arranged along the second direction D2 (See FIG. 9D).

The first and second cover sheets 300 and 350 may cover a plurality of cells 100. The first and second cover sheets 300 and 350 may be opposed to each other. A plurality of cells 100 may be interposed between the first and second cover sheets 300, 350. In an embodiment, the first cover sheet 300 may cover the upper surfaces of the cells 100. For example, the first cover sheet 300 covers the top surface of the first cell 101, the top surface of the second cell 102, the top surface of the third cell 103, and the top surface of the fourth cell 104 . The second cover sheet 350 may cover the lower surfaces of the cells 100. For example, the second cover sheet 350 is disposed on the lower surface 101b of the first cell 101, the lower surface of the second cell 102, the lower surface of the third cell 103, You can cover the underside.

The first and second cover sheets 300 and 350 may function to protect the plurality of cells 100 from the external environment. The first and second cover sheets 300 and 350 may be made of a transparent material. The first and second cover sheets 300 and 350 may include a polybutylacrylate material, a polyurethane material, and / or an ethylene vinyl acetate material.

The upper electrode portions 210 and 220 may be positioned on the upper surfaces of the cells 100. The lower electrode portions 230 and 240 may be positioned on the lower surfaces of the cells 100. The upper electrode portions 210 and 220 may be positioned between the cells 100 and the first cover sheet 300. The lower electrode portions 230 and 240 may be positioned between the cells 100 and the second cover sheet 350.

The upper electrode portions 210 and 220 are formed on the upper surface of the first cell 101, the upper surface of the second cell 102, the upper surface of the third cell 103, Lt; / RTI > The lower electrode portions 230 and 240 may be provided on the lower surface of the first cell 101, the lower surface of the second cell 102, the lower surface of the third cell 103, have.

The upper electrode portions 210 and 220 may include upper conductive patterns 220 and upper metal wires 210. In an embodiment, the lower electrode portions 230 and 240 may include lower conductive patterns 240 and lower metal wires 230. In another example, the lower electrode portion may include lower conductive patterns 240 and electrode pads that cover the lower surface of the cells 100.

The upper conductive patterns 220 and the lower conductive patterns 240 may be busbars. The upper metal wires 210 and the lower metal wires 230 may be fingers.

The upper metal wires 210 may be connected to the upper conductive patterns 220. The lower metal wires 230 may be connected to the lower conductive patterns 240. The upper and lower metal wires 210 and 230 may function to collect carriers (electrons and / or holes) generated in the cells 100. The upper and lower conductive patterns 220 and 240 may output carriers (electrons and / or holes) collected from the upper and lower metal wires 210 and 230 to the outside. The width of the upper and lower conductive patterns 220 and 240 may be approximately 1,000 μm to approximately 2,000 μm and the width of the upper and lower metal wires 210 and 230 may be approximately 10 μm to approximately 100 μm.

Each of the upper and lower conductive patterns 220 and 240 may be in the form of a line or a bar extending in the second direction D2. Each of the upper and lower metal wires 210 and 230 may be in a line or bar shape extending in a first direction D1. In an embodiment, the longitudinal sides of the upper and lower metal wires 210, 230 may be substantially circular.

The upper conductive patterns 220 include a first upper conductive pattern 221, a second upper conductive pattern 222, a third upper conductive pattern 223, and a fourth upper conductive pattern 224 can do. The first upper conductive pattern 221 is provided between the upper surface of the first cell 101 and the first cover sheet 300 and the second upper conductive pattern 222 is provided between the upper surface of the second cell 102 and the upper surface And may be provided between the cover sheet 300. The third upper conductive pattern 223 is provided between the upper surface of the third cell 103 and the first cover sheet 300 and the fourth upper conductive pattern 224 is provided between the upper surface of the fourth cell 104 and the upper surface And may be provided between the cover sheet 300. The first to fourth upper conductive patterns 221, 222, 223, and 224 may be arranged at regular intervals along the first direction D1.

The upper metal wires 210 may include first upper metal wires 211, second upper metal wires 212, third upper metal wires 213, and fourth upper metal wires < RTI ID = 0.0 > 214 < / RTI > The first upper metal wires 211 may be provided between the upper surface of the first cell 101 and the first cover sheet 300. Second upper metal wires 212 may be provided between the upper surface of the second cell 102 and the first cover sheet 300. Third upper metal wires 213 may be provided between the upper surface of the third cell 103 and the first cover sheet 300. Fourth upper metal wires 214 may be provided between the upper surface of the fourth cell 104 and the first cover sheet 300.

In an embodiment, the first upper metal wires 211 may be arranged at regular intervals along the second direction D2. One end of the first upper metal wires 211 can be connected to the first upper conductive pattern 221. The second upper metal wires 212 may be arranged at regular intervals along the second direction D2. One end of the second upper metal wires 212 may be connected to the second upper conductive pattern 222. The second upper metal wires 212 may be located in the first direction D1 from the first upper metal wires 211. The third upper metal wires 213 may be arranged at regular intervals along the second direction D2. One end of the third upper metal wires 213 may be connected to the third upper conductive pattern 223. The third upper metal wires 213 may be located in the first direction D1 from the second upper metal wires 212. [ The fourth upper metal wires 214 may be arranged at regular intervals along the second direction D2. One end of the fourth upper metal wires 214 may be connected to the fourth upper conductive pattern 224. The fourth upper metal wires 214 may be located in the first direction D1 from the third upper metal wires 213. [ Details of the first to fourth upper metal wires 211, 212, 213, and 214 will be described later.

The lower conductive patterns 240 include a first lower conductive pattern 241, a second lower conductive pattern 242, a third lower conductive pattern 243, and a fourth lower conductive pattern 244 can do. The first lower conductive pattern 241 is provided between the lower surface of the first cell 101 and the second cover sheet 350 and the second lower conductive pattern 242 is provided between the lower surface of the second cell 102 and the lower surface of the second And may be provided between the cover sheets 350. The third lower conductive pattern 243 is provided between the lower surface of the third cell 103 and the second cover sheet 350 and the fourth lower conductive pattern 244 is provided between the lower surface of the fourth cell 104 and the lower surface of the second And may be provided between the cover sheets 350. The first to fourth lower conductive patterns 241, 242, 243, and 244 may be arranged at regular intervals along the first direction D1.

In embodiments, the bottom metal wires 230 may include first bottom metal wires 231, second bottom metal wires 232, third bottom metal wires 233, and fourth bottom metal wires 234). The first lower metal wires 231 may be provided between the lower surface of the first cell 101 and the second cover sheet 350. The second lower metal wires 232 may be provided between the lower surface of the second cell 102 and the second cover sheet 350. Third lower metallic wires 233 may be provided between the lower surface of the third cell 103 and the second cover sheet 350. The fourth lower metal wires 234 may be provided between the lower surface of the fourth cell 104 and the second cover sheet 350.

In an embodiment, the first lower metal wires 231 may be arranged at regular intervals along the second direction D2. One end of the first lower metal wires 231 may be connected to the first lower conductive pattern 241. The second lower metal wires 232 may be arranged at regular intervals along the second direction D2. One end of the second lower metal wires 232 can be connected to the second lower conductive pattern 242. The second lower metal wires 232 may be located in the first direction D1 from the first lower metal wires 231. [ The third lower metal wires 233 may be arranged at regular intervals along the second direction D2. One end of the third lower metal wires 233 can be connected to the third lower conductive pattern 243. The third bottom metal wires 233 may be positioned in the first direction D1 from the second bottom metal wires 232. The fourth lower metal wires 234 may be arranged at regular intervals along the second direction D2. One end of the fourth lower metal wires 234 can be connected to the fourth lower conductive pattern 244. The fourth lower metal wires 234 may be positioned in the first direction D1 from the third lower metal wires 233. [ Details of the first to fourth lower metal wires 231, 232, 233, and 234 will be described later.

The upper metal wires 210 may be inserted into the upper grooves UG provided on the upper surface of the cells 100. [ The lengths of the upper metal wires 210 may be smaller or substantially the same as the lengths of the upper grooves UG.

The lower metal wires 230 may be inserted into the lower grooves LG to be provided on the lower surface of the cells 100. The lengths of the lower metal wires 230 may be smaller or substantially equal to the lengths of the lower grooves LG. The upper metal wires 210 and the lower metal wires 230 may be vertically overlapped. The lengths of the upper and lower metal wires 210 and 230 may mean the length of the first direction D1 in plan view.

Hereinafter, the positional relationship of the plurality of cells 100 will be described. Portions of adjacent cells 100 may overlap each other. Each of the cells 110 may form a slope with the first direction D1.

In an embodiment, the one end region of the first cell 101 and the other end region of the second cell 102 may be vertically overlapped. The first lower conductive pattern 241 may be located at one end region of the first cell 101 and the second upper conductive pattern 222 may be located at the other end region of the second cell 102. The first lower conductive pattern 241 and the second upper conductive pattern 222 may be vertically overlapped with each other. And the other end region of the second cell 102 may be positioned below the one end region of the first cell 101. [

The one end region of the second cell 102 and the other end region of the third cell 103 may be vertically overlapped. The second lower conductive pattern 242 may be located at one end region of the second cell 102 and the third upper conductive pattern 223 may be located at the other end region of the third cell 103. The second lower conductive pattern 242 and the third upper conductive pattern 223 may be vertically overlapped with each other. And the other end region of the third cell 103 may be positioned below the one end region of the second cell 102.

The one end region of the third cell 103 and the other end region of the fourth cell 104 may vertically overlap. The third lower conductive pattern 243 may be located at one end region of the third cell 103 and the fourth upper conductive pattern 224 may be located at the other end region of the fourth cell 104. The third lower conductive pattern 243 and the fourth upper conductive pattern 224 may be vertically overlapped with each other. The other end region of the fourth cell 104 may be located under one end region of the third cell 103. Accordingly, the first through fourth cells 101, 102, 103, and 104 may be arranged along the first direction D1 in a shingled structure.

The upper conductive patterns 220 and the lower conductive patterns 240 of the adjacent cells 100 may be connected to the conductive adhesive 400. Accordingly, the cells 100 can be electrically connected to each other. For example, the conductive adhesive 400 may be positioned between the first lower conductive pattern 241 and the second upper conductive pattern 222, which are overlapped with each other. The conductive adhesive 400 may bond the first lower conductive pattern 241 and the second upper conductive pattern 222. Accordingly, the first cell 101 and the second cell 102 may be electrically connected to each other.

Each of the plurality of cells 100 may include a plurality of semiconductor layers. The details of this will be described later with reference to FIG.

The electronic device 20 may be electrically connected to the solar cell 10. For example, the electronic device 20 may be electrically connected to the upper conductive pattern 221 of the first cell 101 and the lower conductive patterns 244 of the fourth cell 104. The electronic device may be, but is not limited to, a battery that stores the converted electrical energy in the solar cell 10.

5 is a cross-sectional view taken along line II-II 'of FIG. 6 is an enlarged view of the area B in Fig. 7 is an enlarged view of the area C in Fig.

In an embodiment, each of the cells 100 may be of substantially the same structure. Each of the upper metal wires 210 may be of substantially the same structure. Each of the lower metal wires 230 may be of substantially the same structure. Accordingly, for convenience of explanation, the first cell 101, the first upper metal wires 211, and the first lower metal wires 231 will be mainly described.

5 to 7, the first cell 101 may have a top surface 101a and a bottom surface 101b opposite to each other. Each of the upper surface 101a and the lower surface 101b may be a texturing surface. As a result, the light reflectance on the upper surface 101a and the lower surface 101b can be reduced. For example, on the textured surface of the upper surface 101a and the lower surface 101b, light is incident and reflected, and most of the light can be absorbed into the first cell 101. Accordingly, the light absorption rate of the first cell 101 is increased, and the efficiency of the solar cell 10 can be improved.

Direct light may be incident on the upper surface 101a of the first cell 101. [ Reflected light may be incident on the lower surface 101b of the first cell 101. [ The reflected light may be light reflected from the ground by albedo. In the embodiment, the direct light incident on the upper surface 101a and the reflected light incident on the lower surface 101b may be absorbed into the first cell 101. [

In an embodiment, the first cell 101 may include first through third semiconductor layers 110, 120, and 130 that are sequentially stacked. For example, the first to third semiconductor layers 110, 120, and 130 may be sequentially stacked in a third direction D3 perpendicular to the first and second directions D1 and D2. In another example, the first semiconductor layer 110 may be omitted.

The second semiconductor layer 120 may be interposed between the first semiconductor layer 110 and the third semiconductor layer 130. The first semiconductor layer 110 may cover the lower surface of the second semiconductor layer 120 and the third semiconductor layer 130 may cover the upper surface of the second semiconductor layer 120. The upper surface 101a of the first cell 101 may be the upper surface of the third semiconductor layer 130 and the lower surface 101b of the first cell 101 may be the lower surface of the first semiconductor layer 110. In this embodiment, Lt; / RTI >

The second semiconductor layer 120 may be a silicon substrate having a first conductivity type. The silicon substrate may be a single crystal silicon substrate, a polycrystalline silicon substrate, or an amorphous silicon substrate. In an embodiment, the second semiconductor layer 120 may be a polycrystalline silicon substrate.

The first semiconductor layer 110 may have a first conductivity type. The first conductivity type may be n-type. Accordingly, the first and second semiconductor layers 110 and 120 may contain impurities of pentavalent elements such as phosphorus, arsenic, or antimony. The impurity concentration of the first semiconductor layer 110 may be greater than that of the impurities of the second semiconductor layer 120. In an embodiment, the first semiconductor layer 110 may be a back surface field layer, BSF). The first lower grooves LG1 may be formed in the first semiconductor layer 110. [

The third semiconductor layer 130 may have a second conductivity type different from the first conductivity type. The second conductivity type may be p-type. Accordingly, the third semiconductor layer 130 may contain an impurity of a trivalent element such as boron, gallium, or indium. In an embodiment, the third semiconductor layer 130 may be an emitter layer of the solar cell 10 (see FIG. 1). A p-n junction may be formed between the third semiconductor layer 130 and the second semiconductor layer 120. In another example, the first conductivity type may be p-type and the second conductivity type may be n-type. The first upper grooves UG1 may be formed in the third semiconductor layer 130. [

The first cell 101 may have first upper grooves UG1 and second lower grooves UG2. The width W1 of the first upper grooves and the width W2 of the second lower grooves may be about 20 탆 to about 100 탆, but are not limited thereto.

The first upper metal wires 211 may include a core portion 211a and a peripheral portion 211b. The core portion 211a may include a first metal. The peripheral portion 211b may include a second metal having a higher electrical conductivity than the first metal. The first metal may include at least one of copper (Cu), aluminum (Al), tungsten (W), and nickel (Ni), but is not limited thereto. The second metal may include, but is not limited to, silver (Ag) and gold (Au).

The peripheral portion 211b may surround the core portion 211a. The longitudinal section of the core portion 211a may be provided in a substantially circular shape, but is not limited thereto. The longitudinal section of the peripheral portion 211b may be provided in a cylindrical shape having a hollow therein, but is not limited thereto.

The first upper metal wires 211 may be provided on the lower surface of the first cover sheet 300. For example, the first upper metal wires 211 may be attached on the lower surface of the first cover sheet 300. The first cover sheet 300 may be attached to the upper surface 101a of the first cell 101. [ Accordingly, the first cover sheet 300 can cover the upper surface 101a and the first upper grooves UG1.

The first upper metal wires 211 may be inserted into the first upper grooves UG1 of the first cell 101. [ In the embodiment, when the first cover sheet 300 is attached to the upper surface 101a of the first cell 101, the first upper metal wires 211 can be inserted into the first upper grooves UG1 . The width of the first upper metal wires 211 may be substantially the same as the width W1 of the first upper grooves UG1.

The first upper metal wires 211 inserted into the first upper grooves UG1 may contact the inner walls of the first upper grooves UG1. The voids V may be formed between the first upper metal wires 211 inserted into the first upper grooves UG1 and the inner walls of the first upper grooves UG1. That is, the first upper metal wires 211 may not completely fill the first upper grooves UG1. The amount of the second metal of the first upper metal wires 211 is less than the amount of the second metal of the first upper metal wires 211, Can be reduced by the volume.

The first lower metal wires 231 may include a core portion 231a and a peripheral portion 231b. The core portion 231a may include a first metal (for example, copper (Cu)). The peripheral portion 231b may include a second metal (for example, silver (Ag)) having a higher electrical conductivity than the first metal. The peripheral portion 231b may surround the core portion 231a.

The first lower metal wires 231 may be provided on the upper surface of the second cover sheet 350. For example, the first lower metallic wires 231 may be attached on the lower surface of the second cover sheet 350. The second cover sheet 350 can be attached to the lower surface 101b of the first cell 101. [ Accordingly, the second cover sheet 350 can cover the lower surface 101b and the first lower grooves LG1.

The first lower metal wires 231 may be inserted into the first lower grooves LG1 of the first cell 101. [ In the embodiment, when the second cover sheet 350 is attached to the lower surface 101b of the first cell 101, the first lower metal wires 221 can be inserted into the first lower grooves LG1 . The width of the first lower metal wires 231 may be substantially the same as the width W2 of the first lower grooves LG1.

The first lower metal wires 231 inserted into the first lower grooves LG1 may contact the inner walls of the first lower grooves LG1. The voids V may be formed between the first lower metal wires 231 inserted in the first lower grooves LG1 and the inner walls of the first lower grooves LG1. That is, the first lower metal wires 231 may not completely fill the first lower grooves LG1. The amount of the second metal of the first lower metal wires 231 is greater than the amount of the second metal of the first lower metal wires 231, Can be reduced by the volume.

8 is a cross-sectional view illustrating a modification of the solar cell module according to an embodiment of the present invention. For the sake of brevity, descriptions of components substantially the same as those described with reference to Figs. 1 to 7 will be omitted or briefly explained.

8, the solar cell 11 includes a plurality of cells 100, upper electrode units 210 and 220, lower electrode units 230 and 240, a first cover sheet 300, Lt; RTI ID = 0.0 > 350 < / RTI > The plurality of cells 100 may be spaced apart from each other. For example, the plurality of cells 100 may be arranged at regular intervals along the first direction D1. That is, the plurality of cells 100 may not be arranged in a shading structure.

The solar cell 11 may further include upper connection patterns 250 and lower connection patterns 260. The upper connection patterns 250 may be provided on the lower surface of the first cover sheet 300. The upper connection patterns 250 may include a first upper connection pattern 251, a second upper connection pattern 252, and a third upper connection pattern 253.

The first to third upper connection patterns 251, 252 and 253 may include first horizontal portions 251a, 252a and 253a and first vertical portions 251b, 252b and 253b. In the embodiment, the first horizontal portions 251a, 252a, and 253a may be connected to the second through fourth upper conductive patterns 222, 223, and 224, respectively. For example, the first horizontal portion 251a of the first upper connection pattern 251 is connected to the second upper conductive pattern 222 and extends from the second upper conductive pattern 222 toward the first cell 101 Can be extended.

In an embodiment, the first vertical portions 251b, 252b, and 253b may extend from the first horizontal portions 251a, 252a, and 253a toward the second cover sheet 350. The first vertical portions 251b, 252b, and 253b may be positioned between the adjacent cells 100. FIG.

The lower connection patterns 260 may be provided on the upper surface of the second cover sheet 350. The lower connection patterns 260 may include a first lower connection pattern 261, a second lower connection pattern 262, and a third lower connection pattern 263.

The first to third lower connection patterns 261, 262 and 263 may include second horizontal portions 261a, 262a and 263a and second vertical portions 261b, 262b and 263b. In the embodiment, the second horizontal portions 261a, 262a, and 263a may be connected to the first through third lower conductive patterns 241, 242, and 243. For example, the second horizontal portion 261a of the first lower connection pattern 261 is connected to the first lower conductive pattern 241 and extends from the first upper conductive pattern 221 toward the second cell 102 Can be extended.

In an embodiment, the second vertical portions 261b, 262b, 263b may extend from the second horizontal portions 261a, 262a, 263a toward the first cover sheet 300. [ The second vertical portions 261b, 262b, and 263b may be positioned between adjacent cells 100.

The second vertical portions 261b, 262b, and 263b may be connected to the first vertical portions 251b, 252b, and 253b. For example, the first vertical portions 251b, 252b, and 253b and the second vertical portions 261b, 262b, and 263b may be bonded to each other by a conductive adhesive agent. Accordingly, the upper connection pattern 250 and the lower connection pattern 260 which are adjacent to each other can be connected to each other. The upper connection pattern 250 and the lower connection pattern 260 which are adjacent to each other are connected to each other so that the plurality of cells 100 can be electrically connected to each other.

Hereinafter, the manufacturing processes of the solar cell 10 will be described.

FIGS. 9A to 9H are views for explaining manufacturing processes of the solar cell of FIG. For the sake of brevity, descriptions of components substantially the same as those described with reference to Figs. 1 to 7 will be omitted or briefly explained.

3, 5, 9A, and 9B, a cell substrate 15 including first to third semiconductor layers 110, 120, and 130 may be prepared. The cell substrate 15 may have an upper surface 15a and a lower surface 15b opposite to each other. A plurality of first finger grooves G1 may be formed on the upper surface 15a of the cell substrate 15. [ At this time, each of the first finger grooves G1 may be elongated along the first direction D1. The first finger grooves G1 may be arranged at regular intervals in the second direction D2.

A plurality of second finger grooves G2 may be formed on the lower surface 15b of the cell substrate 15. [ At this time, each of the second finger grooves G2 may be elongated along the first direction D1. The second finger grooves G2 may be arranged at regular intervals in the second direction D2. In the embodiment, the number of the first finger grooves G1 and the number of the second finger grooves G2 may be the same. The first finger grooves G1 and the second finger grooves G2 may overlap with each other in plan view.

The first finger grooves G1 and the second finger grooves G2 may be formed through an etching process or a laser ablation process. After forming the second finger grooves G2, the cell substrate 15 may be cut along the dotted lines shown in Fig. 9B. For example, the cell substrate 15 can be cut through a laser cutting process. The dotted lines in FIG. 9B may be arranged in the first direction D1 at regular intervals.

Referring to FIG. 9C, a plurality of cells 100 can be separated from the cell substrate 15 (see FIG. 9B) by a cutting process. In an embodiment, four cells 100 may be separated from the cell substrate 15, but the number of cells 100 is not limited thereto. Each of the plurality of cells 100 may have top grooves UG. The upper grooves UG may be separated from the first finger grooves G1 (see Fig. 9A). As described above, the upper grooves UG may include first upper grooves UG1, second upper grooves UG2, third upper grooves UG3, and fourth upper grooves UG4.

The upper conductive patterns 220 may be formed on the separated cells 100. The upper conductive patterns 220 may be formed by printing (for example, screen printing) a conductive material on the upper surfaces of the separated cells 100. That is, the upper conductive patterns 220 may be formed through a printing process. The conductive material may be silver (Ag) or aluminum (Al), but is not limited thereto.

The printing process may use a stencil mask that defines a position at which the upper conductive patterns 220 are to be formed. A metal paste (for example, aluminum paste or silver paste) may be provided on the stencil mask to print the upper conductive patterns 220 on upper surfaces of the cells 100, respectively.

The first upper conductive pattern 221 is formed on the upper surface of the first cell 101 across the first upper grooves UG1 and the second upper conductive pattern 222 is formed on the upper side of the first upper grooves UG2, And may be formed on the upper surface of the second cell 102. The third upper conductive pattern 223 is formed on the upper surface of the third cell 103 across the third upper grooves UG3 and the fourth upper conductive pattern 224 is formed on the upper side of the third upper grooves UG4, And may be formed on the upper surface of the fourth cell 104.

Referring to FIG. 9D, each of the plurality of cells 100 may have a bottom groove LG. The lower grooves LG may be separated from the second finger grooves G2 (see Fig. 9B). As described above, the lower grooves LG may include first lower grooves LG1, second lower grooves LG2, third lower grooves LG3, and fourth lower grooves LG4.

The lower conductive patterns 240 may be formed in the separated cells 100. [ The method of forming the lower conductive patterns 240 may be substantially the same as the method of forming the upper conductive patterns 220 (see FIG. 9C) described above.

The first lower conductive pattern 241 is formed on the lower surface of the first cell 101 across the first lower grooves LG1 and the second lower conductive pattern 242 is formed on the lower surface of the first cell 101 across the second lower grooves LG2 May be formed on the lower surface of the second cell 102. The third lower conductive pattern 243 is formed on the lower surface of the third cell 103 across the third lower grooves LG3 and the fourth lower conductive pattern 244 is formed on the lower surface of the third cell 103, And may be formed on the lower surface of the fourth cell 104.

The upper conductive patterns 220 and the lower conductive patterns 240 are formed on the upper surface 15a (see FIG. 9A) of the cell substrate 15 before the cutting process of the cell substrate 15 (see FIG. 9B) 15b, Fig. 9b).

Referring to FIG. 9E, a plurality of cells 100 may be electrically connected. In an embodiment, a plurality of cells 100 may be arranged along a first direction D1 such that some of the cells 100 adjacent to each other overlap each other. For example, the first cell 101 and the second cell 102 are arranged along the first direction D1 so that the first lower conductive pattern 241 and the second upper conductive pattern 222 are vertically overlapped with each other can do. At this time, the first lower conductive pattern 241 may be positioned in the third direction D3 from the second upper conductive pattern 222.

The overlapped first lower conductive pattern 241 and the second upper conductive pattern 222 may be bonded to each other. For example, the first lower conductive pattern 241 and the second upper conductive pattern 222 may be bonded to each other by a conductive adhesive agent 400 (see FIG. 4). Accordingly, the first lower conductive pattern 241 and the second upper conductive pattern 222 can be electrically connected. The first lower conductive pattern 241 and the second upper conductive pattern 222 are electrically connected to each other so that the first cell 101 and the second cell 102 can be electrically connected.

The second cell 102 and the third cell 103 may be arranged along the first direction D1 such that the second lower conductive pattern 242 and the third upper conductive pattern 223 overlap vertically. The overlapped second lower conductive pattern 242 and the third upper conductive pattern 223 may be bonded to each other. Accordingly, the second cell 102 and the third cell 103 can be electrically connected.

The third cell 103 and the fourth cell 104 may be arranged along the first direction D1 such that the third lower conductive pattern 243 and the fourth upper conductive pattern 224 vertically overlap. The overlapped third lower conductive pattern 243 and the fourth upper conductive pattern 224 may be bonded to each other. Accordingly, the third cell 103 and the fourth cell 104 can be electrically connected. As shown in FIG. 9E, the first through fourth cells 101, 102, 103, and 104 may be arranged in a shingled structure, and may be electrically connected to each other.

Referring to FIG. 9F, a plurality of upper metal wires 210 may be formed on the first cover sheet 300. For example, upper metal wires 210 may be attached on the lower surface 300a of the first cover sheet 300. [ The upper metal wires 210 may be arranged on the lower surface 300a of the first cover sheet 300 along the first and second directions D1 and D2. That is, the upper metal wires 210 may be arranged in a matrix structure on the lower surface 300a of the first cover sheet 300. [

The widths W3 of the upper metal wires 210 may be substantially the same as the widths W1 (see Fig. 6) of the upper grooves UG. The lengths of the upper metal wires 210 may be less than or substantially equal to the length of the top grooves UG. The upper metal wires 210 may include first upper metal wires 211, second upper metal wires 212, third upper metal wires 213, and fourth upper metal wires < RTI ID = 0.0 > 214).

The first upper metal wires 211, the second upper metal wires 212, the third upper metal wires 213 and the fourth upper metal wires 214 are aligned in the first direction D1 .

Referring to FIG. 9G, a plurality of lower metal wires 230 may be formed on the second cover sheet 350. For example, the lower metal wires 230 may be attached on the upper surface 350a of the second cover sheet 350. [ The lower metal wires 230 may be arranged on the upper surface 350a of the second cover sheet 350 along the first and second directions D1 and D2. That is, the lower metal wires 230 may be arranged in a matrix structure on the upper surface 350a of the second cover sheet 350. [

The widths W4 of the lower metal wires 230 may be substantially the same as the widths W2 (see Fig. 7) of the lower grooves LG. The lengths of the lower metal wires 230 may be less than or substantially equal to the length of the bottom grooves LG. In embodiments, the bottom metal wires 230 may include first bottom metal wires 231, second bottom metal wires 232, third bottom metal wires 233, and fourth bottom metal wires 234).

The first lower metal wires 231, the second lower metal wires 232, the third lower metal wires 233 and the fourth lower metal wires 234 are aligned in the first direction D1 .

Referring to FIG. 9H, a first cover sheet 300 provided with upper metal wires 210 may be placed on top of the cells 100. The second cover sheet 350 provided with the lower metal wires 230 can be positioned below the cells 100. [ For example, the lower surface 300a of the first cover sheet 300 and the upper surface 350a of the second cover sheet 350 may be spaced apart from each other. The first cover sheet 300 may be spaced from the cells 100 in the third direction D3 and the cells 100 may be spaced from the second cover sheet 350 in the third direction D3. Accordingly, the cells 100 can be positioned between the first cover sheet 300 and the second cover sheet 350. [ Further, the first cover sheet 300, the second cover sheet 350, and the cells 100 may be positioned so as to overlap with each other.

Referring again to FIG. 3, the first cover sheet 300 may be attached onto the upper surfaces of the plurality of cells 100. That is, the first cover sheet 300 can be attached on the upper surfaces of the cells 100 through a lamination process. At this time, the upper metal wires 210 provided in the first cover sheet 300 can be inserted into the upper grooves UG. For example, the first upper metal wires 211 may be inserted into the first upper grooves UG1, and the second upper metal wires 212 may be inserted into the second upper grooves UG2. The third upper metal wires 213 may be inserted into the third upper grooves UG3 and the fourth upper metal wires 214 may be inserted into the fourth upper grooves UG4. The upper metal wires 210 may be connected to the upper conductive patterns 220 and may contact the cells 100.

The second cover sheet 350 can be attached on the lower surfaces of the plurality of cells 100. [ That is, the second cover sheet 350 can be attached on the lower surfaces of the cells 100 through a lamination process. At this time, the lower metal wires 230 provided on the second cover sheet 350 can be inserted into the lower grooves LG. For example, the first lower metal wires 231 may be inserted into the first lower grooves LG1, and the second lower metal wires 232 may be inserted into the second lower grooves LG2. The third lower metal wires 233 may be inserted into the third lower grooves LG3 and the fourth lower metal wires 234 may be inserted into the fourth lower grooves LG4. The lower metal wires 230 may be connected to the lower conductive patterns 240 and may contact the cells 100.

The upper metal wires 210 and the lower metal wires 230 may be formed in the plurality of cells 100 through a lamination process of the first and second cover sheets 300 and 350 . Accordingly, the manufacturing process of the solar cell 10 can be simplified and productivity can be improved.

10A to 10E are views for explaining the manufacturing processes of the solar cell of FIG. For the sake of simplicity of explanation, description of components substantially the same as those described with reference to Figs. 8, 9A to 9H will be omitted or briefly explained.

Referring to FIG. 10A, a cell substrate 15 may be prepared. A plurality of first finger grooves G1 may be formed on the upper surface 15a of the cell substrate 15. [ The upper bus grooves UBG intersecting the first finger grooves G1 may be formed on the upper surface 15a of the cell substrate 15. [ In an embodiment, the upper bus grooves UBG may extend longer along the second direction D2. The upper bus grooves UBG may be arranged at regular intervals along the first direction D1.

In the embodiment, the upper bus grooves UBG include a first upper bus groove UBG1, a second upper bus groove UBG2 spaced from the first upper bus groove UBG1 in the first direction D1, A third upper bus groove UBG3 spaced from the bus groove UBG2 in the first direction D1 and a fourth upper bus groove UBG4 spaced from the third upper bus groove UBG3 in the first direction D1. ).

Referring to FIG. 10B, a plurality of second finger grooves G2 may be formed on the lower surface 15b of the cell substrate 15. The lower bus grooves LBG intersecting the second finger grooves G2 may be formed on the lower surface 15b of the cell substrate 15. [ In an embodiment, the lower bus grooves LBG may be elongated along the second direction D2. The lower bus grooves LBG may be arranged at regular intervals along the first direction D1.

In the embodiment, the lower bus grooves LBG include a first lower bus groove LBG1, a second lower bus groove LBG2 spaced from the first lower bus groove LBG1 in the first direction D1, A third lower bus groove LBG3 spaced from the bus groove LBG2 in the first direction D1 and a fourth lower bus groove LBG4 spaced from the third lower bus groove LBG3 in the first direction D1. ).

After forming the second finger grooves G2 and the lower bus grooves LBG, the cell substrate 15 can be cut along the dotted lines shown in Fig. 10B. The dotted lines may not overlap with the upper bus grooves UBG and the lower bus grooves LBG.

Referring to FIG. 10C, a plurality of upper metal wires 210, upper conductive patterns 220, and upper connection patterns 250 may be formed on the first cover sheet 300. For example, the upper metal wires 210, the upper conductive patterns 220, and the upper connection patterns 250 may be attached on the lower surface 300a of the first cover sheet 300. In another example, upper metal wires 210, upper conductive patterns 220, and upper connecting patterns 250 may be formed on the lower surface 300a of the first cover sheet 300 through a printing process. have.

The upper conductive patterns 220 may be connected to the upper metal wires 210. Each of the upper conductive patterns 220 may be elongated along the second direction D2. The upper conductive patterns 220 may be spaced apart at regular intervals along the first direction D1. The upper conductive patterns 220 may include a first upper conductive pattern 221 connected to one end of the first upper metal wires 211 and a second upper conductive pattern 221 connected to one end of the second upper metal wires 212. [ A third upper conductive pattern 223 connected to one end of the third upper metal wires 213 and a fourth upper conductive pattern 224 connected to one end of the fourth upper metal wires 214. [ . ≪ / RTI >

The upper connection patterns 250 may be connected to the upper conductive patterns 220. The number of upper connection patterns may be smaller than the number of upper conductive patterns. For example, the solar cell 11 (see FIG. 8) may include three upper connection patterns 250 and four upper conductive patterns 220. In an embodiment, the upper connection patterns 250 may include first through third upper connection patterns 251, 252, and 253. The first to third upper connection patterns 251, 252, and 253 may be spaced apart in the first direction D1. Each of the first to third upper connection patterns 251, 252 and 253 may be elongated along the second direction D2.

The first upper connection pattern 251 may be connected to the second upper conductive pattern 222 between the first upper metal wires 211 and the second upper metal wires 212. In this embodiment, The second upper connection pattern 252 may be connected to the third upper conductive pattern 223 between the second upper metal wires 212 and the third upper metal wires 213. The third upper connection pattern 253 may be connected to the fourth upper conductive pattern 224 between the third upper metal wires 213 and the fourth upper metal wires 214.

Referring to FIG. 10D, a plurality of lower metal wires 230, lower conductive patterns 240, and lower connection patterns 260 may be formed on the second cover sheet 350. The lower metal wires 230, the lower conductive patterns 240 and the lower connection patterns 260 are electrically connected to the upper metal wires 210 (see FIG. 10C), the upper conductive patterns 220 (see FIG. May be formed on the upper surface 350a of the second cover sheet 350 in substantially the same manner as the method of forming the upper connection patterns 250 (see FIG. 10C).

The number of the lower connection patterns 260 may be smaller than the number of the lower conductive patterns 240. For example, the solar cell 11 includes three lower connection patterns 260, and may include four lower conductive patterns 240. In the embodiment, the lower connection patterns 260 may include first through third lower connection patterns 261, 262, and 263.

The first lower connection pattern 261 may be connected to the first lower conductive pattern 241 at the first lower metal wires 231 and the second lower metal wires 232. The second lower connection pattern 262 may be connected to the second lower conductive pattern 242 between the second lower metal wires 232 and the third lower metal wires 233. [ The third lower connection pattern 263 may be connected to the third lower conductive pattern 243 between the third lower metal wires 233 and the fourth lower metal wires 234.

Referring to FIG. 10E, a plurality of cells 100 may be arranged at regular intervals along the first direction D1. Accordingly, spacing spaces may be formed between the cells 100. [

The first cover sheet 300 provided with the upper metal wires 210 can be placed on top of the cells 100. The second cover sheet 350 provided with the lower metal wires 230 can be positioned below the cells 100. [ The cells 100 may be positioned between the first cover sheet 300 and the second cover sheet 350.

Referring again to FIG. 8, the first cover sheet 300 may be attached to the upper surfaces of the cells 100. That is, the first cover sheet 300 can be attached on the upper surfaces of the cells 100 through a lamination process.

The first cover sheet 300 can be attached on the upper surfaces of the plurality of cells 100. [ That is, the first cover sheet 300 can be attached on the upper surfaces of the cells 100 through a lamination process. At this time, the upper metal wires 210 provided in the first cover sheet 300 can be inserted into the upper grooves UG. The upper conductive patterns 220 provided on the first cover sheet 300 can be inserted into the upper bus grooves UBG. The upper connection patterns 250 provided in the first cover sheet 300 can be located in a space between the cells 100. [

The second cover sheet 350 can be attached on the lower surfaces of the cells 100. [ That is, the second cover sheet 350 can be attached on the lower surfaces of the cells 100 through a lamination process. At this time, the lower metal wires 230 provided in the second cover sheet 350 can be inserted into the lower grooves LG. The lower conductive patterns 240 provided in the second cover sheet 350 can be inserted into the lower bus grooves LBG. The lower connection patterns 260 provided in the second cover sheet 350 can be located in a space between the cells 100. [ The second vertical portions 261b, 262b and 263b of the lower connection patterns 260 may be bonded to the first vertical portions 251b, 252b and 253b of the upper connection patterns 250 by a conductive adhesive. Accordingly, the lower connection patterns 260 may be electrically connected to the upper connection patterns 250.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

1: solar cell module 10, 11: solar cell
20: electronic device 100: cells
210: upper metal wires 220: upper conductive patterns
230: lower metal wires 240: lower conductive patterns
250: upper connection patterns 260: lower connection patterns
UG: upper grooves LG: lower grooves
UBG: Upper bus grooves LBG: Lower bus grooves

Claims (11)

A first cell having a plurality of first top grooves on an upper surface thereof;
A first cover sheet covering an upper surface of the first cell;
A plurality of first upper metal wires provided between the first cover sheet and the upper surface of the first cell, the first upper metal wires being inserted into the first upper grooves; And
And a first upper conductive pattern provided between the upper surface of the first cell and the first cover sheet and connected to the first upper metal wires,
Wherein the first upper grooves and the first upper metal wires extend along a first direction. The method according to claim 1,
Each of the first upper metal wires comprising:
A core comprising a first metal; And
And a peripheral portion surrounding the periphery of the core portion and including a second metal having a higher electrical conductivity than the first metal. 3. The method of claim 2,
Wherein the first metal includes at least one of copper (Cu), aluminum (Al), tungsten (W), and nickel (Ni)
And the second metal comprises silver (Ag). The method according to claim 1,
A first lower conductive pattern provided on a lower surface of the first cell, the first lower conductive pattern being spaced apart from the first upper conductive pattern in the first direction;
A second cell having a plurality of second upper grooves extending along the first direction on an upper surface thereof;
A second upper conductive pattern provided on the upper surface of the second cell and connected to the first lower conductive pattern; And
And a plurality of second upper metal wires inserted in the second upper grooves,
Wherein the first lower conductive pattern and the second upper conductive pattern overlap each other. 5. The method of claim 4,
Wherein the first cover sheet covers the upper surface of the second cell and the second upper conductive pattern,
Wherein the second upper metal wires are positioned between the first cover sheet and the second cell. Forming a plurality of first finger grooves extending in a first direction on an upper surface of the cell substrate;
Cutting the cell substrate on which the first finger grooves are formed to form a first cell having first top grooves and a second cell having second top grooves;
Electrically connecting the first cell and the second cell;
Forming a plurality of upper metal wires on the first cover sheet; And
And attaching the first cover sheet to the upper surface of the first cell and the upper surface of the second cell to insert the upper metal wires into the first upper grooves and the second upper grooves . The method according to claim 6,
Forming a first upper conductive pattern on an upper surface of the first cell and a second upper conductive pattern on an upper surface of the second cell; And
Further comprising forming a first lower conductive pattern on a lower surface of the first cell and forming a second lower conductive pattern on a lower surface of the second cell,
Wherein the first lower conductive pattern is spaced apart from the first upper conductive pattern in the first direction,
And the second lower conductive pattern is spaced apart from the second upper conductive pattern in the first direction. 8. The method of claim 7,
Electrically connecting the first cell to the second cell comprises:
And bonding the first lower conductive pattern to the second upper conductive pattern,
Wherein the first lower conductive pattern and the second upper conductive pattern overlap each other. 8. The method of claim 7,
The upper metal wires inserted into the first upper grooves are connected to the first upper conductive pattern,
And the upper metal wires inserted in the second upper grooves are connected to the second upper conductive pattern. The method according to claim 6,
Further comprising forming second finger grooves extending along the first direction on a lower surface of the cell substrate,
Wherein the first cell has first bottom grooves, and the second cell has second bottom grooves. 11. The method of claim 10,
Forming a plurality of bottom metal wires on the second cover sheet; And
Further comprising attaching the second cover sheet to the lower surface of the first cell and the lower surface of the second cell, and inserting the lower metal wires into the first lower grooves and the second lower grooves. Way.

Images