WO2011140815A1

WO2011140815A1 - Solar cell, screen printing plate and solar cell module

Info

Publication number: WO2011140815A1
Application number: PCT/CN2011/000349
Authority: WO
Inventors: 温建军; 葛剑; 黄海涛; 周豪浩; 周杰; 王义华; 王韬; 王寅; 王赟; 杨健; 陈如龙; 薛小兴; 胡建波; 俞超; 吴而义
Original assignee: 无锡尚德太阳能电力有限公司
Priority date: 2010-05-13
Filing date: 2011-03-04
Publication date: 2011-11-17
Also published as: CN101826569A

Abstract

A solar cell (30), a screen printing plate and a solar cell module, belong to the technical field of photovoltaic. The solar cell (30) comprises a cell substrate (17) and an electrode, wherein the electrode is arranged on the substrate (17). The electrode comprises main grid lines (31) and auxiliary grid lines (33). The main grid line (31) comprises a line area (31a) and a thrum area (31b). The construction of the line area (31a) of the main grid line (31) is in a structure comprising at least one thin grid line to reduce the contact area between the main grid line (31) and the substrate (17). The screen printing plate is used for manufacturing the electrode of the solar cell by screen printing; and meshes for composing and forming the main grid lines (31) of the electrode are arranged on the screen printing plate. The solar cell module comprises a plurality of the solar cells. The solar cell and the solar cell module have low cost, and because the compound area between the metal electrode and the silicon in the cell structure is reduced, the conversion efficiency is improved, the output power of the module is increased, and in addition, the reliability is good after an interconnector is welded with a cell plate.

Description

Solar cell, screen and solar cell module

The present invention relates to the field of photovoltaic technology, and in particular to a solar cell, and more particularly to an electrode structure of a solar cell, a screen for manufacturing the electrode, and a solar cell module including the plurality of solar cells. Background technique

In view of the limited supply of conventional energy sources and the increasing pressure on environmental protection, many countries in the world have set off a boom in the development and utilization of solar energy and renewable energy. Solar energy utilization technology has been rapidly developed, using solar photovoltaic effects to convert solar energy into The use of electrical energy is becoming more widespread. Solar cells are among the most common devices used to convert solar energy into electricity and energy. In practical applications, a battery pack in which a plurality of solar cells are connected in series is generally used as a basic application unit.

Solar cells are the basic unit of solar cell modules. The internal photocurrent generated by solar radiation in the body (such as crystalline silicon) needs to be collected through the electrodes of the battery and collected. The solar cell includes a front electrode and a back electrode, wherein the front electrode is on a face illuminated by sunlight. Taking a front electrode as an example, the front electrode usually includes a main gate line (or referred to as a main gate electrode) and a sub-gate line (or referred to as a sub-gate electrode, a sub-gate line) disposed on a solar cell substrate, wherein The gate line mainly functions to collect current, and the main gate line mainly functions to collect the current collected by the sub-gate line, and is also used as an interconnection strip when a plurality of solar cells are connected through interconnecting strips to form a solar cell module. The connection substrate, that is, the interconnection strip is generally connected in series by soldering or otherwise connecting to the main gate line (the main gate line of the positive electrode or the main gate line of the back electrode). ,

At present, the main problem of the promotion and application of solar power generation is that the power generation cost is much higher than that of traditional thermal power generation. Therefore, reducing the production cost of solar cells and improving the conversion efficiency of batteries have become the direction of the industry.

Reducing the electrode manufacturing cost of solar cells is a direction in the industry to reduce the cost of solar cells. In the prior art, the electrodes of a solar cell are usually patterned by a widely used screen printing technique, i.e., a metal paste is patterned onto a substrate of a monocrystalline silicon wafer cell on which a p-n junction has been formed, and an electrode is formed by sintering. Usually, silver paste is used as a paste for screen printing to form electrodes. The silver paste has strong adhesion, good electrical conductivity, uniform and precise electrode surface, and weldability.

1

Confirmation Good, high battery conversion efficiency, etc., however, due to the expensive nature of silver metal, the cost of solar cells has increased.

Fig. 1 is a schematic view showing the structure of a prior art solar cell, and Fig. 2 is a schematic view showing the structure of the Α-Α cross section of the solar cell shown in Fig. 1. As shown in FIG. 1 and FIG. 2, the bottom of the battery cell 17 of the solar cell 10 (crystalline silicon forming a p-n junction) is patterned into a main gate line 1 1 and a sub-gate line 13 , and a sub-gate line 13 is generally formed. Vertically intersecting with the main gate line 1 1 , the area and height of the main gate lines are also significantly larger or higher than the area and height of the sub-gate lines, respectively.

In order to reduce the cost, it is generally considered in the prior art to reduce the line width of the main gate line or to provide some areas on the main grid line that do not directly print the paste to reduce the amount of silver paste used, but those skilled in the art also recognize that Although reducing the slurry coverage area of the front electrode can reduce the slurry usage amount of the front electrode, some cost can be saved to some extent, but when the line width and the line height of the main gate line are reduced, the series resistance and the main gate line are The cross-sectional area is inversely proportional, so the series resistance is also inevitably increased, which leads to a decrease in solar cell conversion efficiency, which eventually leads to a decrease in the power output of the solar cell module, which may outweigh the gain.

Therefore, in some current designs, although it is considered to reduce the use of the slurry by setting some hollow areas on the main gate line, reducing the composite area between the metal electrode and silicon (such as Ag-Si), to some extent Can reduce the bending of the battery (because the thermal expansion coefficient of metal and silicon is not the same, after sintering and cooling, the battery sheet will bend, the more the amount of slurry used, the greater the amount of bending deformation); However, in design, it tends to Concerning the decrease in battery efficiency caused by the increase in series resistance, the area of these hollowed areas is not large, and the gap between the hollowed areas is also small, so that the slurry itself can be flowed after the paste is printed. Sexuality, covering the area of the unprinted paste, to ensure that the series resistance is not greatly affected (because the flow of the slurry, the hollowed out area is also filled with silver paste, the cross-sectional area of the main grid line is not significantly reduced) . Therefore, in this design, the contact area of the electrode with the silicon substrate is not reduced, and the amount of the slurry used is not particularly significantly reduced. At the same time, since the thermal expansion coefficient of the main gate line of the silver electrode and the silicon of the solar cell substrate is inconsistent, and the area of the main gate line is large and the line height is high, a large thermal stress is generated in the subsequent process of soldering the interconnect strip. Therefore, fragments and cracks are easily generated during the welding process.

In view of this, it is necessary to propose a novel structure that can increase the power output of the solar cell module while greatly reducing the manufacturing cost of the electrode of the solar cell. Summary of the invention One of the objects of the present invention is to substantially reduce the cost of the electrodes of the solar cell and to avoid the occurrence of chipping and cracking during the soldering of the front electrode and the interconnecting strip.

It is still another object of the present invention to improve the conversion efficiency of solar cells and solar cell modules. In order to achieve the object of the present invention, in accordance with one aspect of the present invention, a solar cell includes a battery substrate and an electrode disposed on the battery substrate, the electrode including a main gate line, wherein the main gate The line body region of the wire is configured to include at least one fine grid line to reduce the contact area of the main gate line with the substrate.

As a preferred technical solution, the main gate line includes a first thin gate line and a second fine gate line respectively located at both side edges of the line body region.

As a preferred technical solution, the thin gate line of the line body region of the main gate line is one, and the thin grid line is arranged as a line of a fold line type, which comprises a plurality of segments which are respectively arranged in crossover on the edges of both sides of the line body region. Fine grid line. The line body region of the main gate line further includes at least one test point, and the thin gate line in the shape of a broken line is divided into a plurality of segments by the test point, and two ends of each of the fine gate lines are respectively associated with the test point Electrical connection. The two ends of each segment of the fine grid line may be electrically connected to the test point on the same side of the line body region; the two ends of each segment of the fine grid line may also be electrically connected to the test point on different sides of the line body region .

Preferably, the fine gate line has a line width of 0.1 to 0.5 mm.

Preferably, the first fine gate line and the second fine gate line are parallel to each other and the width of the line body region is 1.2 to 2 mm.

According to an embodiment of the solar cell provided by the present invention, the body region of the main gate line further includes at least one test point, and the test point is electrically connected to the fine gate line.

The test points may be configured as a rectangle or may be configured to include a plurality of lines.

According to an embodiment of the solar cell provided by the present invention, the main gate line further includes at least one head region located at a head portion of the line body region. The head region can be constructed in a triangular shaped tip shape. The line head area may be provided with a hollowed out area.

Preferably, the hollowed out region is circular and has a diameter of 50 to 400 microns. Preferably, the width of the main gate line of the line header region is the same as the width of the main gate line of the line body region.

According to still another aspect of the present invention, the present invention provides a screen for screen-printing an electrode of the above solar cell, wherein the screen is provided with a main grid for patterning the electrode. a pattern of meshes through which the slurry passes; wherein the line body region of the main gate line is configured to include at least one fine gate line to reduce connection of the main gate line to the battery substrate Touch area.

As a preferred technical solution, the thin gate line of the line body region of the main gate line is one, and the thin gate line is arranged as a line of a fold line type.

Preferably, the fine gate line has a line width of 0.1 to 0.5 mm.

Preferably, the width of the body region of the main gate line is 1.2 to 2 mm.

As a preferred technical solution, the screen further includes a pattern for a mesh for passing the slurry corresponding to the line head region for patterning the main gate line, wherein a plurality of regions or blocks for preventing the passage of the slurry are provided. .

According to still another aspect of the present invention, the present invention provides a solar cell module, characterized in that the solar cell module includes any one of the above-mentioned solar cells, and the solar cells are connected by interconnecting strips. The interconnecting strip is connected to a main gate line of an electrode of the solar cell.

The interconnect strip is bonded to the main gate line of the electrode of the solar cell by bonding or soldering, and the interconnect strip covers the entire main gate line.

The technical effect of the present invention is that the present invention is configured to include a structure including at least one fine gate line by the line body region of the main gate line to greatly reduce the contact area between the main gate line and the substrate, and the cross-sectional area of the main gate line is also Therefore, the idea is that the contact area between the original main gate line and the substrate and the cross-sectional area of the main gate line cannot be reduced, the slurry usage amount and the coverage area of the slurry are greatly reduced, and the solar cell is lowered. the cost of. In addition, in the case where the printing area of the slurry is greatly reduced, on the one hand, the recombination between the metal electrode and the silicon can be reduced, and the conversion efficiency of the battery and the module can be improved; on the other hand, after the interconnection strip is welded, the reduction can be reduced. The stress of the main gate line when soldering the interconnect strip (the stress is caused by the inconsistent thermal expansion and shrinkage coefficient of the main gate line of the silver electrode and the silicon of the solar cell substrate), thereby avoiding the fragmentation and hidden phenomenon caused by the soldering process. Crack phenomenon.

As for the problem of reduced battery efficiency due to an increase in series resistance caused by a decrease in the cross-sectional area of the main gate line, since one of the functions of the main gate line is to solder the connection interconnection strip to form a solar cell module, usually mutual The cross-sectional area of the strips is much larger than the cross-sectional area of the main grid lines, usually more than 10 times different; and it can be experimentally proved that the contact resistance of the interconnect strips with the main gate lines (for example, by lead-tin alloy soldering) Smaller, has little effect on the overall resistance. Therefore, considering the overall perspective of the solar cell module, even the series connection of the main gate lines The resistance increases, and the interconnected strips on the main gate line are the main current paths in the assembly. The series resistance on the interconnect strip after soldering is not significantly increased, so it does not affect the conversion of the solar cell components. The efficiency, that is, the increase in the series resistance of the main gate line, does not bring about a significant negative effect from the overall solar cell module. The solar cell module of the invention has the advantages of low cost, high conversion efficiency, increased output power, and high reliability. DRAWINGS

1 is a schematic structural view of a prior art solar cell;

Figure 2 is a schematic view showing the structure of the A-A cross section of the solar cell shown in Figure 1;

3 is a schematic plan view showing a planar structure of a solar cell according to an embodiment of the present invention; FIG. 4 is a schematic structural view of a B-B cross section of the solar cell shown in FIG.

Figure 5 is a plan view showing the planar structure of a solar cell according to another embodiment of the present invention;

Figure 6 is a plan view showing the planar structure of a solar cell according to still another embodiment of the present invention;

Figure 7 is a schematic structural view of a head region of a main grid line of the solar cell shown in Figure 3 according to the present invention;

Fig. 8 is a view showing another configuration of the head region of the main grid line of the solar cell shown in Fig. 3 according to the present invention. detailed description

The following is a description of some of the various possible embodiments of the present invention, which are intended to provide a basic understanding of the invention and are not intended to identify key or critical elements of the invention. In the drawings, it is possible to magnify the thickness of a layer or the area of a region for the sake of clarity, but as a schematic diagram, it should not be considered to strictly reflect the proportional relationship of geometric dimensions. In the drawings, the same reference numerals are used to refer to the same structural parts, and the description thereof will be omitted.

The terms "up, down, left, right, middle, horizontal, etc." as used herein are defined relative to the orientation of the solar cells as illustrated in the drawings. They are relative concepts and can be used according to the solar cell. The different ways vary accordingly.

3 is a schematic view showing the planar structure of a solar cell according to an embodiment of the present invention. As shown in FIG. 3, on the side of the battery cell 17 of the solar cell 30 that is illuminated by sunlight, A front electrode is formed. The front electrode includes a main gate line 31 and a sub-gate line 33. The substrate 17 is a crystalline silicon wafer in which a pn junction has been formed. The specific material type and specific structure of the battery substrate 17 are not limited by the present invention. In the embodiment shown in FIG. 3, a plurality of sub-gate lines 33 are arranged in parallel in the left-right direction and vertically intersected with the two main gate lines 31. The specific number of the sub-gate lines 33 and the main gate lines 31, and the arrangement of the main gate lines 31 and the sub-gate lines 33 are not limited by the embodiment of the present invention.

Fig. 4 is a view showing the structure of the B-B section of the solar cell shown in Fig. 3. 3 and 4, the main gate line 31 includes a line body region 31a, and the main gate line 31 is constructed as a structure including a plurality of thin gate lines. In this embodiment, the line body region of the main gate line 31 31a includes two thin gate lines, that is, a first thin gate line 31 1 and a second fine gate line 312 respectively disposed on both side edges of the line body region 31a, and the first thin gate line 31 1 and the second fine gate line 312 is set in parallel. In addition, the line width of the first fine gate line 31 1 and the second fine gate line 312 ranges from 0.1 to 0.5 mm, and the width of the line body region (the width of the line body region is the distance between the left and right edges, that is, FIG. 4 The W) shown in the range is 1.2 to 2 mm, so that the contact area between the line body region and the substrate is greatly reduced, and the blank area between the first fine gate line 31 1 and the second fine gate line 312 is The area where the silver electrode is deposited. A plurality of sub-gate lines 33 on the battery are in direct communication with the thin gate lines 31 1 and 312 (electrical conduction), so that the fine gate lines 311 and 312 can also achieve current collection of the sub-gate lines. Further, when the solar cell module is formed by the solar cell 30, the thin gate lines 31 1 and 312 are also used to solder the connection interconnection strips to connect the plurality of solar cells in series to form the solar cell module. It should be noted that whether the line widths of the first fine gate line 31 1 and the second fine gate line 312 are equal is not limited by the embodiment of the present invention.

Continuing with FIG. 3, in order to facilitate the need for battery testing, at least one test point 315 is included in the body region of the main gate line 31, and the test point 315 is electrically connected to the main gate line 31. In this embodiment, the test point 315 is disposed between the first fine gate line 311 and the second fine gate line 312. The test point may be a substantially rectangular shape or a test block including a plurality of thin lines having a width of 0.1 to 1 mm. The specific shape of the test point 315 is not limited by the embodiment of the present invention, and is only for detecting The probe provides a measurement point whose specific shape can be designed according to the shape of the detection probe.

FIG. 5 is a schematic view showing the planar structure of a solar cell according to still another embodiment of the present invention. As shown in FIG. 5, the line body region 41a of the main gate line 41 of the front surface electrode of the solar cell 40 in this embodiment is configured as a thin line type thin gate line 411, and the test point 415 is disposed on the main gate line 41. The line body region 41a is electrically connected to the thin gate line 41 1 , and the fine gate line 41 1 includes a plurality of segments which are sequentially arranged in a line connecting the thin gate lines of the line body region 41 a to form a polygonal line structure as shown in FIG. 5 . The line width of the fine gate line 41 1 is substantially the same as the line width of the embodiment shown in FIG. For example, the thin gate line 41 1 may have a line width ranging from 0.1 to 0.5 mm, and the plurality of sub-gate lines 43 on the battery are directly connected (electrically conducted) to the thin gate line 41 1 . The fine grid line 41 1 is also used to solder the connection interconnect strips to connect a plurality of solar cells in series to form a solar cell module, and when soldered, the interconnect strips are soldered to the outermost edge of the fold line. Compared to the solar cell 30 of the embodiment shown in Fig. 3, the solar cell 40 is more capable of reducing the contact area of the main gate line with the substrate.

Fig. 6 is a view showing the planar structure of a solar cell according to still another embodiment of the present invention. 5 and FIG. 6, the line body region 41a of the main gate line 41 of the front surface electrode of the solar cell 50 in the present embodiment is similarly configured as a thin line type 51 1 of a fold line type, the main difference being the fold line. The specific structure of the type of fine gate lines 511 is different. Each of the fine gate lines shown in FIG. 5 is connected to the test point on the same side of the line body region; and as shown in FIG. 6, the fine gate line 51 1 is composed of a plurality of segments, and each segment of the fine gate lines is connected through the test point 415. Together, electrical conduction between each other can be achieved, and the two ends of each segment of the fine grid line are respectively connected to the test points on different sides of the line body region. Therefore, in this embodiment, the width of the line body region 41a is determined by the distance between the fine grid lines of the two edges at the test point.

The line body region of the main gate line of the solar cell of the present invention includes only a fine gate line having a very small width and a necessary test point, so that the contact area of the main gate line with the substrate is greatly reduced, that is, the slurry of the main gate line The printing area is also minimized, and the cross-sectional area of the main grid line is also greatly reduced, thereby maximally saving the amount of slurry used and greatly saving the slurry cost.

In addition, in the case where the printing area of the slurry is greatly reduced, on the one hand, the recombination between the metal and the silicon can be reduced, and the conversion efficiency of the battery and the module can be improved; on the other hand, after the interconnection strip is welded, the main reduction can be achieved. The stress of the gate line when soldering the interconnect strip (the stress is caused by the inconsistent thermal expansion and shrinkage coefficient of the silver gate main gate line and the solar cell substrate silicon), thereby facilitating the avoidance of fragmentation and cracking caused by the soldering process. phenomenon.

In the battery main gate line structure of the embodiment as described above, if only the single main gate line is considered, since the cross-sectional area of the main gate line is also greatly reduced, the series resistance of the main gate line is printed relative to the previous full area. The series resistance of the main gate line is increased, but since one of the functions of the main gate line is used to solder the interconnect strip to form a solar cell module, generally the cross-sectional area of the interconnect strip is larger than the cross-sectional area of the main gate line. It is much larger, usually more than 10 times different; and it can be experimentally proved that the contact resistance of the interconnect strip and the main gate line (for example, soldered by lead-tin alloy) Touch) The resistance is small and has little effect on the overall resistance. Therefore, from the overall viewpoint of the solar cell module, even if the series resistance of the main gate line is increased, and the interconnecting strips of the soldered connection on the main gate line are the main current paths, the series resistance on the interconnect strips is not increased, therefore, It does not affect the conversion efficiency of the solar cell module, and the increase in the series resistance of the main gate line does not bring about a significant negative effect from the overall solar cell module.

Continuing with Fig. 3, the head portion 32b of the solar cell of the main grid line 31 is also provided with a wire head region 32b. This is because the main gate line is basically formed by printing and is formed by a sintering process. If the main gate line at the edge of the solar cell is also set to have the same width as the main gate line (line body region 31a) of the intermediate portion, the main body is sintered. At the gate line, the ends are very easy to warp. Therefore, the wire head region 32b is set to a triangular shape having a relatively small area to avoid warping of both end portions.

Fig. 7 is a view showing the structure of a head region of a main grid line of the solar cell shown in Fig. 3 according to the present invention. As shown in Fig. 7, the head region 31b may be further included at both ends of the body portion 31a of the main gate line 31. Both ends of the first fine gate line 31 1 and the second fine gate line 312 are connected to the head region 31b. Wherein at least one of the wire head regions is substantially triangular in shape of a pointed shape, and the wire head region is disposed to include the hollowed out region 316, thereby further reducing the use of the slurry in the wire end region, reducing the compounding, reducing the bending deformation, cracks and fragments of the battery, etc. problem. The hollow region 316 may include a plurality of circular holes, and the diameter of the circular holes may be 50 micrometers to 400 micrometers, which may be selected according to the specific area of the wire head region. It should be noted that the hollow region 316 is not necessarily limited to the circular hole shape of the embodiment, and may be, for example, a square hole shape, a triangular hole shape or the like.

Fig. 8 is a view showing another configuration of the head region of the main grid line of the solar cell shown in Fig. 3 according to the present invention. As shown in Fig. 8, the wire end portion 31b is also substantially a triangular pointed shape, and the triangular shaped wire end portion 31b is surrounded by the extended lines of the thin grid lines 31 1 and 312, and therefore, in this embodiment, the wire end portion The region 31b is configured as a triangle formed by the thin gate lines 31 1b and 312b, wherein the thin gate line 31 1b is an extension of the fine gate line 31 1 and the thin gate line 312b is an extension of the fine gate line 312. The line widths of the fine gate lines 31 1b and 312a may range from 0.1 to 0.5 mm.

It should be noted that the main gate line and the sub-gate line shown above are the shape structure of the front electrode of the solar cell, but the structural design concept of the main gate line can also be applied to the back surface electrode of the solar cell.

According to still another aspect of the present invention, there is provided a screen for screen printing an electrode for manufacturing the above solar cell. The electrodes of the solar cells described above are manufactured by a screen printing process, and the slurry (for example, silver paste) is transferred through the mesh on the screen to the sun. A substrate of the battery is used to achieve a predetermined pattern shape of the electrode. Therefore, in the screen of the invention, the shape of the mesh is matched with the shape of the electrode to be formed (especially the shape of the main grid line), and the screen is provided with a pattern for forming the main gate line described above. A pattern that allows the paddle to pass.

According to still another aspect of the present invention, the present embodiment provides a solar cell module including a plurality of the above-described solar cells, and further comprising a soldering connection to a main gate line of the plurality of solar cells. Connect the interconnects of the solar cells. Specifically, the solar cells are connected in series by interconnecting strips that are soldered or bonded or otherwise attached to the main grid of the electrodes. In conjunction with the embodiment of the solar cell shown in FIG. 3 or FIG. 5, the interconnect strips may be soldered to the fine gate lines 3 1 1 and 3 12 or soldered to the fine gate lines 41 1 to cover the entire main gate line as a whole. . Generally, the cross-sectional area of the interconnect strip is much larger than the cross-sectional area of the main gate line, generally more than 10 times different, and it can be experimentally proved that the contact resistance of the interconnect strip and the main gate line (for example, by lead-tin alloy soldering contact) The resistance is small and has little effect on the overall resistance. Therefore, from the overall point of view of the solar cell module, even if the series resistance of the main gate line increases, and the interconnected strips on the main gate line are connected as the main current path, the series resistance on the interconnect strip after soldering does not increase significantly. Therefore, it does not affect the conversion efficiency of the solar cell module, and the increase in the series resistance of the main gate line does not bring about a relatively significant negative effect from the entirety of the solar cell module. Conversely, since the contact area of the main gate line with the substrate is reduced (the area where the paste printing area is greatly reduced), the cost of the solar cell module is lowered, the conversion efficiency is increased, and the reliability is improved (it is easy to avoid the debris generated by the splicing process). Phenomenon and cracking phenomenon).

The above example mainly illustrates the structure, screen and solar cell module of the solar cell of the present invention by taking the front electrode of the battery as an example. Although only a few of the embodiments of the present invention have been described, it will be understood by those skilled in the art that the present invention may be embodied in many other forms without departing from the spirit and scope of the invention. Accordingly, the present invention is to be construed as illustrative and not restrictive, and the invention may cover various modifications without departing from the spirit and scope of the invention as defined by the appended claims With replacement.

Claims

Rights request

A solar cell comprising a battery substrate and an electrode disposed on the battery substrate, the electrode comprising a main gate line, wherein the line body region of the main gate line is configured to include at least one thin The gate line is structured to reduce the contact area of the main gate line with the substrate.

2. The solar cell according to claim 1, wherein the main gate line comprises a first thin gate line and a second fine gate line respectively located at both side edges of the line body region.

The solar cell according to claim 1, wherein the thin gate line of the line body region of the main gate line is one, and the fine gate line is arranged to have a line of a fold line type.

The solar cell according to claim 3, wherein the line body region of the main gate line further comprises at least one test point, and the thin line line of the fold line type is divided into a plurality of segments by the test point. Two ends of each of the fine grid lines are electrically connected to the test points.

The solar cell according to claim 4, wherein both ends of each of the thin grid lines are electrically connected to the test point on the same side of the body region.

6. The solar cell of claim 4, wherein each of the two ends of the thin grid line is electrically connected to the test point on a different side of the body region.

The solar cell according to claim 1, wherein the fine gate line has a line width of 0.1 to 0.5 mm.

The solar cell according to claim 2, wherein the first fine gate line and the second fine gate line are parallel to each other and a width of the line region of the main gate line is 1.2 to 2 mm.

9. The solar cell of claim 2, wherein the body region of the main gate line further comprises at least one test point, the test point being electrically connected to the fine gate line.

The solar cell according to claim 9, wherein the test point is configured in a rectangular shape.

1 1. The solar cell of claim 9, wherein the test point is configured to include a plurality of lines.

12. The solar cell of claim 1, wherein the main gate line further comprises at least one head region located at a head of the line body region.

The solar cell according to claim 12, wherein the wire head region is configured in a triangular pointed shape.

The solar cell according to claim 12, wherein the wire head region is provided with a hollowed out region.

The solar cell according to claim 14, wherein the hollow region is circular and has a diameter of 50 to 40 (H Kaimi.

The solar cell according to claim 12, wherein the wire end region is configured in a triangular shape composed of a thin grid line.

17. A screen for electroplating an electrode for manufacturing a solar cell, characterized in that the screen is provided with a pattern for patterning a mesh of a main gate line forming the electrode through which a slurry passes. Wherein the body region of the main gate line is configured to include at least one thin gate line to reduce a contact area of the main gate line with the substrate.

18. The screen according to claim 17, wherein the main gate line comprises a first thin gate line and a second fine gate line respectively located at both side edges of the line body region.

19. The screen according to claim 17, wherein the thin gate line of the body region of the main gate line is one, and the fine grid line is disposed as a line of a fold line type.

The screen according to claim 17, wherein the fine grid line has a line width of 0.1 to 0.5 mm.

21. The screen according to claim 17, further comprising a pattern for passing a mesh through which the slurry passes to form a head region of the main gate line, wherein a plurality of blocking pastes are disposed The area passed.

A solar cell module, characterized in that the solar cell module comprises a plurality of solar cells according to claim 1, wherein the solar cells are connected by interconnecting strips,

The solar cell module according to claim 22, wherein the interconnecting strip is connected to a main gate line of an electrode of the solar cell by bonding or soldering, and the interconnecting strip covers On the entire main grid line.