Solar cell sheet

Abstract

The utility model provides a solar cell piece which comprises a main grid line and an auxiliary grid line, the main grid line and the auxiliary grid line intersect, the main grid line is provided with a first centipede pin, the auxiliary grid line is provided with a second centipede pin, the first centipede pin and the second centipede pin are both located at the intersection position of the main grid line and the auxiliary grid line, and the first centipede pin and the second centipede pin are located at the intersection position of the main grid line and the auxiliary grid line. And the second centipede foot is overlapped above the first centipede foot. According to the solar cell provided by the invention, the centipede pin structures are arranged on the main grid lines, so that grid breakage is avoided, and the yield of products is improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a solar cell. Background Art

[0002] As global warming becomes more and more serious, it is urgent to reduce global carbon dioxide emissions. Most countries in the world have reached a consensus and set carbon peak and carbon neutrality goals. Solar energy is inexhaustible and not restricted by region. Solar photovoltaic cells are one of the best solutions to the problem of climate warming because they are clean and renewable.

[0003] Solar cells are mainly PERC cells (Passivated Emitter Rear Cell). In recent years, with the rapid development of materials and equipment technology, the efficiency of PERC crystalline silicon cells has increased very rapidly, and the cost has dropped very quickly, getting closer and closer to the cost of thermal power. In many countries, it can now achieve grid parity. The mass-produced PERC+SE (Selective Emitter) cells add SE technology to the original PERC cells, and the cell efficiency is significantly improved.

[0004] As the front screen of the solar cell production line is changed from single printing to distributed printing, especially the introduction of mass production of main grid MBB (Multi-Busbar), the fine grid line width is getting narrower and the height is getting lower, which helps to reduce silver consumption and reduce the shading area to improve the efficiency of solar cells. The overlap height of the centipede feet on the fine grid and the main grid is also getting lower and lower. Due to the low height of the centipede feet, the welding of the component is easily deviated and the centipede feet melt, resulting in broken grids of the component, which greatly reduces the product yield. Utility Model Content

[0005] To achieve the above-mentioned purpose, the present application provides a solar cell sheet, which avoids grid breakage and improves the product yield by setting a centipede foot structure on the main grid line.

[0006] The present application provides a solar cell sheet, comprising a main grid line and a secondary grid line, wherein the main grid line and the secondary grid line intersect each other, the main grid line is provided with a first centipede foot, and the secondary grid line is provided with a second centipede foot, the first centipede foot and the second centipede foot are both located at the intersection of the main grid line and the secondary grid line, and the second centipede foot is stacked on top of the first centipede foot.

[0007] Furthermore, the area of ​​the second centipede leg is greater than that of the first centipede leg, and the second centipede leg completely covers the first centipede leg.

[0008] Furthermore, the extension direction of the main grid line is perpendicular to the extension direction of the first centipede leg, the extension direction of the auxiliary grid line is consistent with the extension direction of the second centipede leg, and the first centipede leg and the second centipede leg are axially symmetrically arranged relative to the main grid line or the auxiliary grid line.

[0009] Furthermore, the length of the first centipede leg and / or the second centipede leg is between 0.2 and 2 mm, the width is between 0.01 and 2 mm, and the thickness is between 0.001 and 0.02 mm.

[0010] Furthermore, the cross-sectional shape of the first centipede leg and / or the second centipede leg is one of a rectangular shape, a diamond shape, a boat shape or a runway shape.

[0011] Furthermore, it also includes multiple wiring points, which are arranged at intervals along the main grid line and electrically connected to the main grid line. The main grid line is electrically connected to the first centipede foot, the first centipede foot and the second centipede foot are electrically connected, and the auxiliary grid line is electrically connected to the main grid line through the second centipede foot and is electrically connected to the wiring points.

[0012] Furthermore, it includes a laser spot, the extension direction of which is perpendicular to the extension direction of the main grid line, and the laser spot is set to avoid the position where the first centipede leg is located.

[0013] Furthermore, the laser spot is arranged to avoid the position where the main grid line and / or the wiring point are located.

[0014] Furthermore, the number of the main grid lines and the number of the secondary grid lines are both multiple, the first centipede legs and the second centipede legs are both multiple, the multiple main grid lines and / or the multiple secondary grid lines are evenly spaced, and the multiple first centipede legs and the multiple second centipede legs are arranged at the intersection of the main grid lines and the secondary grid lines.

[0015] Furthermore, the number of the main grid lines is less than the number of the secondary grid lines, and the cross-sectional area of ​​the main grid lines is greater than the cross-sectional area of ​​the fine grid lines.

[0016] In the solar cell sheet provided by the present application, the main grid line and the auxiliary grid line intersect, the main grid line is provided with a first centipede foot, the auxiliary grid line is provided with a second centipede foot, the first centipede foot and the second centipede foot are both located at the intersection of the main grid line and the auxiliary grid line, and the second centipede foot is superimposed on the first centipede foot. Therefore, relative to the existing scheme in which the main grid line is not provided with a centipede foot, the main grid line is also provided with a first centipede foot, and the second centipede foot is overlapped and arranged above the first centipede foot, which can generally increase the height of the centipede foot. When the component welding process is performed, even if the welding is biased, the centipede foot will not melt, thereby avoiding the occurrence of the solar cell sheet grid breakage situation, and can improve the product yield. In addition, the intersection of the main grid line and the auxiliary grid line is changed from the existing line-to-surface contact to the surface-to-surface contact of the centipede foot, which can reduce the contact cell, which is conducive to reducing the cell series resistance of the solar cell sheet, thereby avoiding the dissipation of current, thereby improving the power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0018] Figure 1 A schematic diagram of the distribution structure of the main grid lines of the solar cell sheet provided in this application;

[0019] Figure 2 for Figure 1 An enlarged structural diagram of the main grid line;

[0020] Figure 3 It is a schematic diagram of the distribution structure of the main grid lines and auxiliary grid lines of the solar cell sheet provided by the present application;

[0021] Figure 4 for Figure 3 A schematic diagram of the enlarged structure of the main grid line and the auxiliary grid line;

[0022] Figure 5 for Figure 4 A schematic diagram of an enlarged structure at the intersection of the main grid line and the auxiliary grid line;

[0023] Figure 6 Another schematic diagram of the distribution of the main grid lines of the solar cell provided in the present application, which shows the distribution of the laser spot;

[0024] Figure 7 for Figure 6 An enlarged schematic diagram of the main grid line.

[0025] Description of Figure Numbers:

[0026]

[0027]

[0028] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in this application to clearly and completely describe the technical solutions in this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] It should be noted that all directional indications in this application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0031] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0032] In the screen printing process of PERC solar cell production line, the main grid non-burn-through silver paste is usually printed first, and the secondary grid burn-through silver paste is printed later. In the grid line graphic design of conventional production lines, the main grid connection line is not provided with centipede feet, and the secondary grid is provided with centipede feet to overlap the main grid connection line. Due to the cost reduction of the production line, the thickness of the secondary grid screen needs to be reduced and the wet weight of the silver paste is reduced. Therefore, the height of the secondary grid centipede feet is also reduced. If the position of the component welding ribbon is slightly offset, it is easy to melt the low-height centipede feet, resulting in the occurrence of component grid breakage, and the product yield is greatly reduced.

[0033] In view of this, refer to Figures 1 to 7The present application provides a solar cell panel 100, which is provided with a main grid line 101 and a secondary grid line 102, the main grid line 101 and the secondary grid line 102 intersect, the main grid line 101 is provided with a first centipede foot 111, and the secondary grid line 102 is provided with a second centipede foot 121, the first centipede foot 111 and the second centipede foot 121 are both located at the intersection of the main grid line 101 and the secondary grid line 102, and the second centipede foot 121 is overlapped on the first centipede foot 111.

[0034] Specifically, the main grid line 101 and the auxiliary grid line 102 are usually arranged on the front side of the solar cell 100, where the main grid line 101 is a non-burn-through silver paste grid line, and the auxiliary grid line 102 is a burn-through silver paste grid line. The burn-through silver paste means that the bottom surface of the silver paste can be exposed through high-temperature sintering, so that it can contact the passivation layer of the solar cell 100, thereby collecting the charge or current of the passivation layer of the solar cell 100, wherein the main grid line 101 and the auxiliary grid line 102 intersect, the main grid line 101 is provided with a first centipede foot 111, and the auxiliary grid line 102 is provided with a second centipede foot 121, the first centipede foot 111 and the second centipede foot 121 are both located at the intersection of the main grid line 101 and the auxiliary grid line 102, and the second centipede foot 121 is overlapped on the first centipede foot 111. Therefore, compared with the existing scheme in which the main grid line is not provided with centipede feet, in the solar cell sheet 100 provided by the present application, the main grid line 101 is also provided with a first centipede foot 111, and the second centipede foot 121 is overlapped and arranged above the first centipede foot 111, which can generally increase the height of the centipede foot. When the assembly welding process is performed, even if the welding is biased, the centipede foot will not melt, thereby avoiding the occurrence of grid breakage of the solar cell sheet and improving the product yield. In addition, the intersection of the main grid line 101 and the auxiliary grid line 102 is changed from the existing line-to-surface contact to the surface-to-surface contact of the centipede foot, which can reduce the contact cell, which is conducive to reducing the cell series resistance of the solar cell sheet, thereby avoiding the dissipation of current, thereby improving the power generation efficiency.

[0035] Reference Figure 4 and Figure 5 In some embodiments of the present application, the area of ​​the second centipede leg 121 is greater than the area of ​​the first centipede leg 111 , and the second centipede leg 121 completely covers the first centipede leg 111 .

[0036] Specifically, as described above, in the screen printing process of the solar cell sheet 100, the main grid line 101 is printed first, and then the auxiliary grid line 102 is printed. Therefore, the area of ​​the second centipede foot 121 is larger than the area of ​​the first centipede foot 111, so that it can be ensured that the second centipede foot 121 completely covers the top of the first centipede foot 111, and ensures that the second centipede foot 121 can fully contact with the first centipede foot 111, thereby ensuring that the height of the centipede foot is increased. When the component welding process is performed, even if the welding is biased, the centipede foot will not melt, thereby avoiding the occurrence of grid breakage of the solar cell sheet, and improving the product yield. At the same time, the solar cell sheet 100 provided in the present application, through the above settings, can ensure that the intersection of the main grid line 101 and the auxiliary grid line 102 is changed from the existing line-to-surface contact to the surface-to-surface contact of the centipede foot, which can reduce the contact cell, which is beneficial to reducing the battery series resistance of the solar cell sheet, thereby avoiding the dissipation of current, thereby improving the power generation efficiency.

[0037] Reference Figures 4 to 5 In some embodiments of the present application, the extension direction of the main grid line 101 is perpendicular to the extension direction of the first centipede leg 111, the extension direction of the secondary grid line 102 is consistent with the extension direction of the second centipede leg 121, and the first centipede leg 111 and the second centipede leg 121 are axially symmetrically arranged relative to the main grid line 101 or the secondary grid line 102.

[0038] Specifically, Figures 3 to 5 As shown, the first centipede foot 11 and the second centipede foot 121 both extend in the horizontal direction, that is, the first centipede foot 11 and the second centipede foot 121 extend in the same direction, and the first centipede foot 111 and the second centipede foot 121 are arranged axially symmetrically relative to the main grid line 101 or the auxiliary grid line 102, so that it can further ensure that the second centipede foot 121 completely covers the top of the first centipede foot 111, and ensure that the second centipede foot 121 can fully contact with the first centipede foot 111, thereby ensuring that the height of the centipede foot is increased. When the component welding process is performed, even if the welding is biased, the centipede foot will not melt, thereby avoiding the occurrence of the grid break of the solar cell sheet, and improving the product yield. At the same time, the solar cell sheet 100 provided by the present application, through the above arrangement, can ensure that the intersection of the main grid line 101 and the auxiliary grid line 102 is changed from the existing line-to-surface contact to the surface-to-surface contact of the centipede foot, which can reduce the contact cell, which is conducive to reducing the battery series resistance of the solar cell sheet, thereby avoiding the dissipation of current, thereby improving the power generation efficiency.

[0039] Meanwhile, the first centipede leg 111 and the second centipede leg 121 are axially symmetrically arranged relative to the main grid line 101 or the auxiliary grid line 102 , and the structure is simple, thus facilitating the manufacture of the first centipede leg 111 and the second centipede leg 121 .

[0040] Furthermore, in some embodiments of the present application, the length of the first centipede leg 111 and / or the second centipede leg 121 is between 0.2 and 2 mm, the width is between 0.01 and 2 mm, and the thickness is between 0.001 and 0.02 mm. The size of the first centipede leg 111 and / or the second centipede leg 121 is set in this way to ensure the strength of the first centipede leg 111 and / or the second centipede leg 121, and further ensure that the second centipede leg 121 can be in full contact with the first centipede leg 111, thereby ensuring that the height of the centipede leg is increased. When the component welding process is performed, even if the welding is off-center, the centipede leg will not melt, thereby avoiding the occurrence of broken grids in solar cells and improving product yield.

[0041] In addition, in some embodiments of the present application, the cross-sectional shape of the first centipede leg 111 and / or the second centipede leg 121 is one of a rectangular, diamond, boat-shaped or runway-shaped, so as to increase the contact area between the second centipede leg 121 and the first centipede leg 111, further ensuring that the second centipede leg 121 can fully contact the first centipede leg 111, and thereby ensuring that the height of the centipede leg is increased. When the component welding process is performed, even if the welding is off-center, the centipede leg will not melt, thereby avoiding the occurrence of broken grids in solar cells and improving product yield.

[0042] It is understandable that the cross-sectional shape of the first centipede leg 111 and / or the second centipede leg 121 may also be other shapes, such as a trapezoid, etc. The specific shape depends on the actual situation and is not limited here.

[0043] Reference Figures 2 to 4 In some embodiments of the present application, the solar cell 100 also includes a plurality of wiring points (PAD points) 103, and the plurality of wiring points 103 are arranged at intervals along the main grid line 101 and are electrically connected to the main grid line 101. The main grid line 101 is electrically connected to the first centipede foot 111, the first centipede foot 111 is electrically connected to the second centipede foot 121, and the auxiliary grid line 102 is electrically connected to the main grid line 101 through the second centipede foot 121, and is electrically connected to the wiring point 103.

[0044] Specifically, the function of the wiring point 103 is to conduct the current or charge on the front side of the solar cell panel 100 by welding with the welding strip. The wiring point 103 is distributed in a dot matrix and is electrically connected to the main grid line 101. The auxiliary grid line 102 collects the current or charge on the front side of the solar cell panel 100, and conducts it to the first centipede foot 111 through the second centipede foot 121, and then transmits it to the wiring point 103 through the main grid line 101. Therefore, the solar cell panel 100 provided in the present application can ensure that the intersection of the main grid line 101 and the auxiliary grid line 102 is changed from the existing line-to-surface contact to the surface-to-surface contact of the centipede feet by stacking the first centipede foot 111 on top of the second centipede foot 121, which can reduce the contact cell, which is beneficial to reducing the cell series resistance of the solar cell panel, thereby avoiding current dissipation and improving power generation efficiency.

[0045] Reference Figure 6 and Figure 7 In some embodiments of the present application, the solar cell sheet 100 includes a laser spot 104 , the extension direction of the laser spot 104 is perpendicular to the extension direction of the main grid line 101 , and the laser spot 104 is configured to avoid the position where the first centipede leg 111 is located.

[0046] Specifically, the SE technology of the PERC cell is a selective emitter technology, that is, the selective heating characteristics of the laser are used to perform high-concentration phosphorus doping at the contact point between the electrode grid line and the silicon wafer to change the conductive characteristics of the cell. The high-concentration doping of the electrode contact area can reduce the contact resistance between the front metal electrode and the silicon wafer. The silver paste used in the auxiliary grid line 102 is a burn-through silver paste, which contacts the passivation layer, so laser heating is required for doping, while the silver paste used in the main grid line 101 is a non-burn-through type, and there is no need to scan the laser spot, and the position of the first centipede leg 111 does not need to scan the laser spot, thereby reducing the damage of the laser to the silicon wafer, thereby being able to increase the current and opening voltage of the solar cell 100, and can improve the power generation efficiency of the cell.

[0047] Reference Figure 6 and Figure 7 In some embodiments of the present application, the laser spot 104 is set to avoid the position of the main grid line 101 and / or the wiring point 103. The silver paste used for the main grid line 101 is a non-burn-through type, and there is no need to scan the laser spot. The function of the wiring point 103 is to conduct the current or charge on the front of the solar cell 100 by welding with the welding ribbon. It does not contact the passivation layer, etc., so there is no need to scan the laser spot for doping treatment, thereby further reducing the damage of the laser to the silicon wafer, thereby increasing the current and opening voltage of the solar cell 100, and improving the power generation efficiency of the cell.

[0048] Refer again Figure 3 and Figure 4In some embodiments of the present application, the number of main grid lines 101 and the number of secondary grid lines 102 are both multiple, the number of first centipede legs 111 and the number of second centipede legs 121 are both multiple, the multiple main grid lines 101 and / or the multiple secondary grid lines 102 are evenly spaced, and the multiple first centipede legs 111 and the multiple second centipede legs 121 are arranged at the intersection of the main grid lines 101 and the secondary grid lines 102.

[0049] Specifically, the main grid line 101 and the secondary grid line 102 are both printed on the front side of the solar cell panel 100 through the screen printing process. The number of the main grid line 101 and the secondary grid line 102 are both multiple, so the first centipede foot 111 and the second centipede foot 121 are both multiple, and the multiple first centipede feet 111 and the multiple second centipede feet 121 are arranged at the intersection of the main grid line 101 and the secondary grid line 102, so as to ensure that the second centipede foot 121 is arranged above the first centipede foot 111 in an overlapping manner at the intersection of the main grid line 101 and the secondary grid line 102, which can increase the height of the centipede foot as a whole. When the component welding process is performed, even if the welding is off-center, the centipede foot will not melt, thereby avoiding the occurrence of broken grids in the solar cell panel and improving the product yield. In addition, the intersection of the main grid line 101 and the auxiliary grid line 102 is changed from the existing line-to-surface contact to the centipede-like surface contact, which can reduce the contact cell and is beneficial to reducing the cell series resistance of the solar cell, thereby avoiding current dissipation and improving power generation efficiency.

[0050] Reference Figures 3 to 5 In some embodiments of the present application, the number of the main grid lines 101 is less than the number of the secondary grid lines 102 , and the cross-sectional area of ​​the main grid lines 101 is greater than the cross-sectional area of ​​the fine grid lines 102 .

[0051] Specifically, in the solar cell 100 provided in the present application, the main grid line 101 is electrically connected to the wiring point 103, and the auxiliary grid line 102 is used to collect the current or charge on the passivation layer of the cell, etc., and is electrically connected to the main grid line 101, so as to be conducted out through the welding strip welded at the wiring point 103. Therefore, the number of auxiliary grid lines 102 is relatively larger and thinner, which is conducive to collecting the current or charge generated in the cell.

[0052] The present application also provides a solar cell panel assembly, including the solar cell panel 100 described above. The specific structure of the solar cell panel 100 refers to the above embodiment. Since the solar cell panel 100 adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0053] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A solar cell sheet, characterized in that: It includes a main grid line and a secondary grid line, the main grid line and the secondary grid line intersect each other, the main grid line is provided with a first centipede foot, the secondary grid line is provided with a second centipede foot, the first centipede foot and the second centipede foot are both located at the intersection of the main grid line and the secondary grid line, and the second centipede foot is stacked on top of the first centipede foot.

2. The solar cell sheet according to claim 1, characterized in that: The area of ​​the second centipede leg is greater than that of the first centipede leg, and the second centipede leg completely covers the first centipede leg.

3. The solar cell sheet according to claim 2, characterized in that: The extension direction of the main grid line is perpendicular to the extension direction of the first centipede leg, the extension direction of the auxiliary grid line is consistent with the extension direction of the second centipede leg, and the first centipede leg and the second centipede leg are axially symmetrically arranged relative to the main grid line or the auxiliary grid line.

4. The solar cell sheet according to claim 3, characterized in that: The length of the first centipede leg and / or the second centipede leg is between 0.2 and 2 mm, the width is between 0.01 and 2 mm, and the thickness is between 0.001 and 0.02 mm.

5. The solar cell sheet according to claim 4, characterized in that: The cross-sectional shape of the first centipede leg and / or the second centipede leg is one of a rectangular shape, a diamond shape, a boat shape or a runway shape.

6. The solar cell sheet according to claim 5, characterized in that: It also includes multiple wiring points, which are arranged at intervals along the main grid line and electrically connected to the main grid line. The main grid line is electrically connected to the first centipede leg, the first centipede leg is electrically connected to the second centipede leg, and the auxiliary grid line is electrically connected to the main grid line through the second centipede leg and is electrically connected to the wiring points.

7. The solar cell sheet according to claim 6, characterized in that: It includes a laser spot, the extension direction of which is perpendicular to the extension direction of the main grid line, and the laser spot is arranged to avoid the position where the first centipede leg is located.

8. The solar cell sheet according to claim 7, characterized in that: The laser spot is arranged to avoid the position where the main grid line and / or the wiring point are located.

9. The solar cell sheet according to claim 8, characterized in that: The number of the main grid lines and the number of the auxiliary grid lines are both multiple, the number of the first centipede legs and the second centipede legs are both multiple, the multiple main grid lines and / or the multiple auxiliary grid lines are evenly spaced, and the multiple first centipede legs and the multiple second centipede legs are arranged at the intersection of the main grid lines and the auxiliary grid lines.

10. The solar cell sheet according to claim 9, characterized in that: The number of the main grid lines is less than the number of the secondary grid lines, and the cross-sectional area of ​​the main grid lines is greater than the cross-sectional area of ​​the secondary grid lines.

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