TOPCon battery screen pattern with novel structure
By disconnecting the secondary gate lines at the open ends of the front and back harpoon structures of the TOPCon battery mesh pattern and running through all secondary gate lines at the center harpoon structure, the problem of inconvenient welding and hidden cracking of the welding tape is solved, and the effect of reducing string resistance and improving the filling factor is achieved.
Patent Information
- Application Number
- CN202421504673.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-28
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-06-28
AI Technical Summary
During the component end soldering process of TOPCon batteries, the solder tape is inconvenient to solder and is prone to soldering, which increases the risk of hidden cracks and may lead to poor contact and blackening of EL.
A new structure of TOPCon battery mesh pattern is designed, including the harpoon structure on the front and back of the battery substrate. By disconnecting the corresponding secondary gate lines at the open ends of the front and back harpoon structures, the welding tape can pass smoothly through and penetrate all secondary gate lines at the central harpoon structure position to reduce string resistance and improve filling factor.
It effectively solves the problem of inconvenient welding and hidden cracking risks of welding tape, reduces series resistance, improves filling factor and component power, and improves the situation of dark edges and black ELs.
Smart Images
Figure CN222885094U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of photovoltaic cells, and in particular relates to a TOPCon cell screen pattern with a new structure. Background Art
[0002] TOPCon cell, namely Tunneling Oxide Passivated Contact Cell (Thin Oxide Passivated Contact), is a new type of solar cell technology. It mainly uses N-type silicon wafer as a carrier. On the basis of PERC cell, a very thin silicon oxide layer (1-2nm) is prepared on the back, namely the tunneling oxide layer. Then, a layer of phosphorus-doped microcrystalline amorphous hybrid silicon film is deposited. During the annealing process, the crystallinity of the hybrid silicon film will change and turn into polycrystalline, forming a passivated contact structure.
[0003] After printing on the surface of the cell, there will be spaced main grid lines and spaced secondary grid lines perpendicular to the main grid lines. In the series welding of the module, it is inconvenient for the welding ribbon to reach the back of the cell from the front, and the secondary grid lines are easy to carry solder, which increases the risk of hidden cracks after the welding ribbon is high. However, if the secondary grid is disconnected at the welding position, there will be poor contact at this position, resulting in the problem of blackening of the EL of the component end. Utility Model Content
[0004] In order to solve the technical problem in the background technology that the welding strip is inconvenient to weld during the component end string welding process, the purpose of the utility model is to provide a new structure of TOPCon battery screen pattern, which can solve the above problem.
[0005] The technical solution for achieving the purpose of the utility model is: a TOPCon battery screen pattern of a new structure, including a battery substrate, a front electrode pattern is printed on the front of the battery substrate, the front electrode pattern includes a plurality of front main grid lines and a plurality of front auxiliary grid lines, a plurality of the front main grid lines and a plurality of the front auxiliary grid lines are printed vertically, a plurality of the front main grid lines are printed at equal distances, a plurality of the front auxiliary grid lines are printed at equal distances, the front electrode printing pattern has an upper and lower symmetrical structure with the horizontal center line of the battery substrate as the dividing line; a plurality of the front main grid lines have a central front harpoon structure and an edge front harpoon structure on both sides, the two front auxiliary grid lines are disconnected at the opening end of the edge front harpoon structure; all the front auxiliary grid lines pass through the position of the central front harpoon structure.
[0006] In this solution, part of the front auxiliary grid lines near the front edge of the battery cell substrate are disconnected at the open end of the front harpoon structure at the edge. This is to ensure that during the component end string soldering process, the soldering ribbon can pass through the front of the battery cell to the back, and the disconnected front auxiliary grid lines are not easy to carry solder, and will not increase the height of the soldering ribbon, thereby reducing the risk of hidden cracks. At the same time, the center of the battery substrate is the starting point for soldering, and there is no penetration of the soldering ribbon. Therefore, the front auxiliary grid lines are completely penetrated at the position of the center front harpoon structure, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce the string resistance, increase the fill factor, increase the component power, and improve the darkening of the edge. All the front auxiliary grid lines are penetrated at the position of the center front harpoon structure, which means that the component at this position does not weld the soldering ribbon. Penetration can prevent the blackening of the EL caused by the disconnection of the harpoon, and increase the contact length of the auxiliary grid to enhance the contact.
[0007] Furthermore, the edges of the two disconnected front auxiliary grid lines at the open end of the edge front harpoon structure protrude into the edge front harpoon structure. Because the disconnection will cause the EL to turn black, the disconnected front auxiliary grid line edges are protruded at this position to ensure contact, which can ensure that the normal components are connected and the EL at the component end is normal.
[0008] Furthermore, the battery screen pattern on the front of the battery substrate adopts a distributed printing method, wherein the front main grid line, the center front harpoon structure and the edge front harpoon structure are printed on one screen, using the front main grid slurry, and the front secondary grid line is printed on another screen, using the front secondary grid slurry. During the printing process, the front harpoon position and the front main grid line are both printed using the front main grid slurry, which can effectively reduce the J0-metal caused by the use of the secondary grid and improve the opening voltage.
[0009] Furthermore, the ends of the two disconnected front auxiliary grid lines protrude in the edge front harpoon structure, and the protruding distance is 50μm-100μm; the open end of the edge front harpoon structure protrudes from the outermost front auxiliary grid line on the battery substrate, and the protruding distance is 50μm-100μm. At the edge front harpoon position, the disconnected front auxiliary grid line will cause the loss of current collection, so the disconnected front auxiliary grid line end is protruded by 50μm-100μm in the edge front harpoon, which can ensure the welding requirements and the normal collection of current. If there is a slight upward and downward deviation in printing, there will be a risk of overlapping the front main grid line and the front auxiliary grid line, so the method of protruding the open end of the edge front harpoon structure from the outermost front auxiliary grid line on the battery substrate by 50μm-100μm is adopted.
[0010] Furthermore, a back electrode pattern is printed on the back of the battery substrate, and the back electrode pattern includes a plurality of back main grid lines and a plurality of back auxiliary grid lines, and the plurality of back main grid lines and the plurality of back auxiliary grid lines are printed vertically, and the plurality of back main grid lines are printed at equal distances, and the plurality of back auxiliary grid lines are printed at equal distances, and the back electrode printing pattern is a vertically symmetrical structure with the horizontal center line of the battery substrate as the dividing line; a plurality of back main grid lines have a central back harpoon structure and an edge back harpoon structure on both sides, and the back auxiliary grid lines at the position of the edge back harpoon structure are all penetrated, and the two back auxiliary grid lines at the opening end of the central back harpoon structure are disconnected. On the back of the battery substrate, because the component string welding is opposite to the front, in the central back harpoon structure near the center position of the back of the battery substrate, the two disconnected back auxiliary grid lines are so that during the component end string welding process, the welding ribbon can pass through the front of the battery cell to the back well, and the disconnection of the front auxiliary grid line is not easy to carry solder, and will not increase the welding ribbon height, reducing the risk of hidden cracks. At the same time, the edge of the back side of the cell substrate is the starting point for welding, and there is no penetration of the welding strip. All the back side secondary grid lines at the harpoon structure position on the edge are penetrated, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce the series resistance, increase the fill factor, increase the component power, and improve the edge darkening. At the same time, during the printing process, because the back side is in contact with poly silicon, there is a passivation effect of poly silicon and tunnel oxide layer, which will not cause an impression on the silicon substrate, and the use of secondary grid slurry in the back side harpoon structure will not reduce the opening voltage.
[0011] Furthermore, the back of the battery substrate adopts a distributed printing method, in which the back main grid line is printed on one screen, using the back main grid slurry, and the back sub-grid line and the back harpoon structure are printed on another screen, using the back sub-grid slurry. The back harpoon structure and the back sub-grid line are both printed with the back sub-grid slurry, which can increase the contact on the back and improve the fill factor.
[0012] By adopting the above technical solution, the utility model has the following beneficial effects:
[0013] (1) Two of the front auxiliary grid lines are disconnected at the open end of the front harpoon structure at the edge of the front side of the battery substrate. During the string welding process at the component end, the soldering ribbon can pass through the front side of the battery cell to the back side. The disconnected front auxiliary grid line is not easy to carry solder, and it will not increase the height of the soldering ribbon, reducing the risk of hidden cracks; at the same time, the edge of the disconnected front auxiliary grid is protruded to ensure contact, which can ensure normal component connection and normal EL at the component end. The front auxiliary grid lines are completely penetrated at the position of the central front harpoon structure, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce string resistance, increase fill factor, increase component power, and improve edge darkening;
[0014] (2) The ends of the two disconnected front auxiliary grid lines protrude into the edge front harpoon structure, and the protruding distance is 50 μm-100 μm, which can meet the welding requirements and also ensure the normal collection of current;
[0015] (3) The open end of the edge front harpoon structure protrudes from the outermost front secondary grid line on the battery substrate, and the protruding distance is 50 μm-100 μm, so as to prevent slight up and down deviation of printing and reduce the risk of overlap between the front main grid line and the front secondary grid line;
[0016] (4) On the back of the battery substrate, because the component string welding is opposite to the front, in the center back harpoon structure near the center of the back of the battery substrate, some back auxiliary grid lines are disconnected. This is to ensure that the welding ribbon can pass through the front of the battery cell to the back during the component end string welding process. The disconnection of the front auxiliary grid line is not easy to carry solder, and it will not increase the height of the welding ribbon, reducing the risk of hidden cracks; at the same time, the edge position of the back of the battery substrate is the starting point, and there is no penetration of the welding ribbon. All the back auxiliary grid lines at the edge back harpoon structure position are penetrated, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce the string resistance, improve the fill factor, increase the component power, and improve the dark edge;
[0017] (4) During the printing process, because the back side of the battery substrate is in contact with polysilicon (polycrystalline silicon layer), there is a passivation effect of polysilicon and tunnel oxide layer, which will not cause impression on the silicon substrate. The use of secondary gate slurry in the back harpoon structure will not lead to a decrease in the opening voltage. Therefore, the back harpoon structure and the back secondary gate line are both printed with the back secondary gate slurry, which can increase the contact on the back side and improve the fill factor. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to make the content of the utility model easier to understand, the utility model is further described in detail according to specific embodiments and in conjunction with the accompanying drawings.
[0019] Figure 1 The front electrode pattern of the battery substrate in the utility model;
[0020] Figure 2 for Figure 1 A magnified view of the harpoon structure on the front of the middle edge;
[0021] Figure 3 Bit Figure 1 A magnified view of the harpoon structure from the center front;
[0022] Figure 4 It is a schematic diagram of printing the front side of the battery substrate on a screen in the utility model;
[0023] Figure 5 It is a schematic diagram of printing the front side of the battery substrate on another screen in the utility model;
[0024] Figure 6 It is the back electrode pattern of the battery substrate in the utility model;
[0025] Figure 7 for Figure 6 A magnified view of the harpoon structure on the back of the mid-margin;
[0026] Figure 8 for Figure 6 A magnified view of the harpoon structure on the back of the center;
[0027] Fig. 9 It is a schematic diagram of printing the back side of the battery substrate on a screen in the utility model;
[0028] Fig.10 This is a schematic diagram of printing the back side of the battery substrate on another screen in the utility model.
[0029] The numbers in the accompanying drawings are: 1 battery substrate; 2 front main grid line; 3 front auxiliary grid line; 4 horizontal center line; 5 center front harpoon structure; 6 edge front harpoon structure; 7 opening end of edge front harpoon structure; 8 two disconnected front auxiliary grid lines; 9 outermost front auxiliary grid line; 10 back main grid line; 11 back auxiliary grid line; 12 center back harpoon structure; 13 edge back harpoon structure; 14 opening end of center back harpoon structure; 15 two disconnected back auxiliary grid lines. DETAILED DESCRIPTION
[0030] Example:
[0031] like Figure 1-Figure 3As shown, this embodiment provides a TOPCon battery screen pattern of a novel structure, including a battery substrate 1, a front electrode pattern is printed on the front of the battery substrate 1, the front electrode pattern includes a plurality of front main grid lines 2 and a plurality of front auxiliary grid lines 3, a plurality of the front main grid lines 2 and a plurality of the front auxiliary grid lines 3 are printed vertically, a plurality of the front main grid lines 2 are printed at equal intervals, a plurality of the front auxiliary grid lines 3 are printed at equal intervals, and the front electrode printing pattern is a vertically symmetrical structure with a horizontal center line 4 of the battery substrate 1 (i.e., the dotted line position in the figure) as a dividing line; a central front harpoon structure 5 and an edge front harpoon structure 6 are provided on both sides of a plurality of the front main grid lines 2, and two of the front auxiliary grid lines 3 are disconnected at an opening end 7 of the edge front harpoon structure; all the front auxiliary grid lines 3 pass through the position of the central front harpoon structure 5. The front auxiliary grid line 3 near the front edge of the cell substrate is partially disconnected at the open end 7 of the front harpoon structure at the edge. This is to ensure that the soldering ribbon can pass through the front of the cell to the back during the component end string welding process. The front auxiliary grid line 3 is not easy to carry solder when it is disconnected, and it will not increase the height of the soldering ribbon, reducing the risk of hidden cracks. At the same time, the center of the cell substrate 1 is the starting point for welding, and there is no penetration of the soldering ribbon. Therefore, the front auxiliary grid lines 3 are completely penetrated at the position of the center front harpoon structure 5, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce the string resistance, improve the fill factor, increase the component power, and improve the darkening of the edge.
[0032] Preferably, the edges of the two front auxiliary grid lines 3 disconnected at the open end 7 of the edge front harpoon structure protrude into the edge front harpoon structure 6. Because the disconnection will cause the EL to turn black, the edges of the disconnected front auxiliary grid lines 3 are protruded at this position to ensure contact, which can ensure that the normal components are connected and the EL at the component end is normal.
[0033] like Figure 2 As shown, the ends of the two disconnected front auxiliary grid lines 8 protrude in the edge front harpoon structure 6, and the protruding distance is 50μm-100μm; the open end 7 of the edge front harpoon structure protrudes from the outermost front auxiliary grid line 9 on the battery substrate 1, and the protruding distance is 50μm-100μm. At the edge front harpoon position, the disconnected front auxiliary grid line 3 will cause the loss of current collection, so the end of the disconnected front auxiliary grid line 3 protrudes 50μm-100μm in the edge front harpoon, which can ensure the welding requirements and the normal collection of current. If there is a slight upward and downward deviation in printing, there will be a risk of overlapping the front main grid line 2 and the front auxiliary grid line 3, so the method of using the open end 7 of the edge front harpoon structure to protrude about 50μm-100μm from the outermost front auxiliary grid line 9 on the battery substrate 1.
[0034] like Figure 4-Figure 5As shown, the battery screen pattern on the front of the battery substrate 1 is printed in a distributed manner, wherein the front main grid line 2, the center front harpoon structure 5 and the edge front harpoon structure 6 are printed on one screen, using the front main grid slurry, and the front secondary grid line 3 is printed on another screen, using the front secondary grid slurry. During the printing process, the front harpoon position and the front main grid line 2 are both printed using the front main grid slurry, which can effectively reduce the J0-metal caused by the use of the secondary grid and improve the opening voltage.
[0035] like Figure 6-Figure 8 As shown, a back electrode pattern is printed on the back of the battery substrate 1, and the back electrode pattern includes a plurality of back main grid lines 10 and a plurality of back auxiliary grid lines 11. The plurality of back main grid lines 10 and the plurality of back auxiliary grid lines 11 are printed vertically, the plurality of back main grid lines 10 are printed at equal intervals, and the plurality of back auxiliary grid lines 11 are printed at equal intervals. The back electrode printing pattern is a vertically symmetrical structure with the horizontal center line 4 of the battery substrate 1 (i.e., the dotted line position in the figure) as the dividing line; a central back harpoon structure 12 and an edge back harpoon structure 13 are provided on both sides of the plurality of back main grid lines 10, and the back auxiliary grid lines 11 at the position of the edge back harpoon structure 13 are all penetrated, and the two back auxiliary grid lines 11 are disconnected at the opening end 14 of the central back harpoon structure. On the back of the battery substrate 1, because the component string welding is opposite to the front, in the center back harpoon structure 12 near the center of the back of the battery substrate 1, the two disconnected back auxiliary grid lines 15 are for the purpose of allowing the welding ribbon to pass through the front of the battery cell to the back during the component end string welding process. The front auxiliary grid line 3 is not easy to carry solder when it is disconnected, and the height of the welding ribbon will not be increased, reducing the risk of hidden cracks. At the same time, the edge position of the back of the battery substrate 1 is the starting point, and there is no penetration of the welding ribbon. All the back auxiliary grid lines 11 at the position of the edge back harpoon structure 13 are penetrated, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce the string resistance, increase the fill factor, increase the component power, and improve the dark edge. At the same time, during the printing process, because the back is in contact with polysilicon, there is a passivation effect of polysilicon and the tunneling oxide layer, which will not cause an impression on the silicon substrate, and the use of auxiliary grid slurry in the back harpoon structure will not reduce the opening voltage.
[0036] like Fig. 9 and Fig.10 As shown, the back of the battery substrate 1 adopts a distributed printing method, wherein the back main grid line 10 is printed on one screen, using the back main grid slurry, and the back sub-grid line 11 and the back harpoon structure are printed on another screen, using the back sub-grid slurry. The back harpoon structure and the back sub-grid line 11 are both printed with the back sub-grid slurry, which can increase the contact on the back and improve the fill factor.
[0037] Working principle: The front auxiliary grid line 3 near the front edge of the battery cell substrate is partially disconnected at the open end 7 of the front harpoon structure at the edge, so that during the component end string welding process, the welding ribbon can pass through the front of the battery cell to the back well, and the front auxiliary grid line 3 is not easy to carry solder when it is disconnected, and it will not increase the height of the welding ribbon, reducing the risk of hidden cracks. At the same time, the center position of the battery substrate 1 is the starting point, and there is no penetration of the welding ribbon. Therefore, the front auxiliary grid lines 3 are completely penetrated at the position of the center front harpoon structure 5, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce the string resistance, increase the fill factor, increase the component power, and improve the dark edge. On the back of the battery substrate 1, because the component string welding is opposite to the front, the two disconnected back auxiliary grid lines 15 in the center back harpoon structure 12 near the center of the back of the battery substrate 1 are so that during the component end string welding process, the welding ribbon can pass through the front of the battery cell to the back well, and the front auxiliary grid line 3 is not easy to carry solder when it is disconnected, and it will not increase the height of the welding ribbon, reducing the risk of hidden cracks. At the same time, the edge of the back side of the battery substrate 1 is the starting point for welding, and there is no welding strip passing through. All the back side auxiliary grid lines 11 at the position of the harpoon structure 13 on the back side of the edge are penetrated, which can reduce the horizontal transmission distance of the photogenerated carriers at the corresponding position, reduce the series resistance, increase the fill factor, improve the component power, and improve the darkening of the edge.
[0038] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A new type of TOPCon battery screen pattern, characterized in that: The invention comprises a battery substrate (1), wherein a front electrode pattern is printed on the front of the battery substrate (1), wherein the front electrode pattern comprises a plurality of front main grid lines (2) and a plurality of front auxiliary grid lines (3), wherein the plurality of front main grid lines (2) and the plurality of front auxiliary grid lines (3) are printed vertically, wherein the plurality of front main grid lines (2) are printed at equal intervals, wherein the plurality of front auxiliary grid lines (3) are printed at equal intervals, and wherein the front electrode printed pattern is a vertically symmetrical structure with a horizontal center line (4) of the battery substrate (1) as a dividing line; a central front harpoon structure (5) and an edge front harpoon structure (6) are provided on both sides of the plurality of front main grid lines (2), wherein two of the front auxiliary grid lines (3) are disconnected at an opening end (7) of the edge front harpoon structure; and all the front auxiliary grid lines (3) are penetrated through the position of the central front harpoon structure (5).
2. The TOPCon battery screen pattern of a novel structure according to claim 1 is characterized in that: The edges of the two front auxiliary grid lines disconnected from the open end of the edge front harpoon structure protrude into the edge front harpoon structure.
3. The TOPCon battery screen pattern of a novel structure according to claim 1 is characterized in that: The ends of the two disconnected front auxiliary grid lines (8) protrude within the edge front harpoon structure (6), and the protruding distance is 50μm-100μm; the open end (7) of the edge front harpoon structure protrudes from the outermost front auxiliary grid line (9) on the battery substrate (1), and the protruding distance is 50μm-100μm.
4. The TOPCon battery screen pattern of a novel structure according to claim 1 is characterized in that: A back electrode pattern is printed on the back of the battery substrate (1), and the back electrode pattern includes a plurality of back main grid lines (10) and a plurality of back sub-grid lines (11). The plurality of back main grid lines (10) and the plurality of back sub-grid lines (11) are printed vertically, the plurality of back main grid lines (10) are printed at equal intervals, and the plurality of back sub-grid lines (11) are printed at equal intervals. The back electrode printed pattern is a vertically symmetrical structure with the horizontal center line (4) of the battery substrate (1) as the dividing line; both sides of the plurality of back main grid lines (10) are provided with a central back harpoon structure (12) and an edge back harpoon structure (13), the back sub-grid lines (11) at the position of the edge back harpoon structure (13) are all penetrated, and the two back sub-grid lines (11) are disconnected at the opening end (14) of the central back harpoon structure.