Electrode structure of solar cell, solar cell and screen plate
By using step-by-step printing technology, the antenna structure is printed in two stages, increasing the width and height of the antennae. This solves the problem of high wet weight of the paste in existing technologies, achieving savings in silver paste and improved welding reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUHU GCL INTEGRATED NEW ENERGY TECH CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-05-29
Smart Images
Figure CN224306220U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic manufacturing, specifically to the electrode structure of solar cells, solar cells, and screen printing plates. Background Technology
[0002] Currently, silver paste costs dominate the non-silicon costs of solar cell production. With the continuous reduction in the consumption of metallization paste per cell, existing cell printing patterns face some challenges at the module level, especially the issue of grid breakage during EL welding.
[0003] The root cause of this problem lies in the breakage of the back contact tip during the high-temperature welding process. During welding, the silver paste from the contact tip is adsorbed onto the solder strip, resulting in insufficient silver paste in the contact tip, thus affecting the tip's height and current conduction. This phenomenon is exacerbated by the symbiotic relationship between the solder strip and the contact tip paste during battery module stringing. As the metallization paste consumption decreases, the height and width of the contact tip gradually shrink. The adsorption effect of the solder strip under high temperatures during welding further leads to excessive adsorption of silver paste from the back contact tip, resulting in insufficient silver paste and ultimately causing a "burning" phenomenon during welding. This results in the breakage of the back contact tip, exhibiting an EL defect characterized by a broken grid.
[0004] Currently, a step-by-step printing technique is commonly used to fabricate the back electrode of solar cells. The specific steps are: the first printing forms the harpoon-shaped main grid lines and solder joint lines; the second printing forms the sub-grid lines, antennas, and border lines. To improve the "burnt" effect on the antennas, a common practice is to increase the width or height of the antennas during the second printing. However, since the antennas are printed together with the sub-grids, adjusting the antenna parameters also affects the sub-grids, leading to an increase in the wet weight of the sub-grid printing, and consequently, a significant increase in the overall wet weight of the printed paste. Utility Model Content
[0005] The purpose of this application is to provide an electrode structure for a solar cell, a solar cell, and a screen printing plate, in order to solve the problem in the prior art that the overall wet weight of the printing paste is high in order to ensure the width and height of the contact structure.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0007] An electrode structure for a solar cell includes:
[0008] The main gate electrode includes a plurality of main gate lines, a plurality of pads, and a plurality of harpoon-shaped connecting lines. The pads are provided on both ends of the main gate lines and on the portion between the two ends. The pads at both ends of the main gate lines are connected to the harpoon-shaped connecting lines.
[0009] The sub-gate electrode includes a plurality of sub-gate lines, some of which intersect and overlap with a plurality of the main gate lines;
[0010] Several antenna structures are disposed at the intersection of the main grid line and the sub-grid line. The length direction of the antenna structure is the same as the extension direction of the sub-grid line. The antenna structure includes a first antenna and a second antenna. The second antenna is superimposed on the first antenna and in contact with the first antenna. The width of the second antenna is smaller than the width of the first antenna.
[0011] In some embodiments, the first antenna includes a main body region and gradient regions located at both ends of the main body region along its length direction. The width of the gradient regions gradually decreases from the main body region toward the distance from the main body region. The main body region is provided with a plurality of perforations at intervals along its length direction.
[0012] The second antenna includes a solid region and transition regions located at both ends of the solid region along its length, the width of which gradually decreases from the solid region toward the distance from the solid region.
[0013] In some embodiments, the length of the second antenna is greater than the length of the first antenna, and the length of the transition zone is greater than the length of the gradient zone.
[0014] In some embodiments, the length of the main body region is 0.81±0.05mm and the width is 0.09±0.01mm;
[0015] The length of the solid region is 0.8±0.05mm, and the width is 0.04±0.01mm;
[0016] The length of the gradient zone is 0.045±0.005mm, and the width decreases from 0.09±0.01mm to 0.033±0.005mm;
[0017] The length of the transition zone is 0.16±0.02mm, and the width is reduced from 0.04±0.01mm to 0.022±0.005mm.
[0018] In some embodiments, the perforation is rectangular, and the width of the second antenna is smaller than the width of the perforation.
[0019] In some embodiments, the height of the antennal structure is greater than 7 μm, and the height of the second antenna is greater than the height of the first antenna.
[0020] In some embodiments, the height of the first antenna is 1.5 μm to 2.5 μm, and the height of the second antenna is 5 μm to 7 μm.
[0021] In some embodiments, the perforated holes are arranged at equal intervals, and the distance between adjacent perforated holes is 0.015±0.005mm.
[0022] This application also provides a solar cell, comprising:
[0023] The battery cell itself;
[0024] The electrode structure described above is disposed on the surface of the battery cell body.
[0025] This application also provides a screen printing plate having a printed pattern, the printed pattern being consistent with the shape of the electrode structure described above.
[0026] Due to the application of the above technical solution, the beneficial effects of this application compared with the prior art are as follows:
[0027] This application increases the width and height of the antenna structure by printing it in two stages. Printing the first antenna simultaneously with the main grid electrode effectively controls the wet weight of the sub-grid electrode and the second antenna, avoiding the problem of excessive wet weight caused by increasing the antenna width and height during the second printing in existing technologies. This method reduces the amount of silver paste used while avoiding paste waste due to increased wet weight. Furthermore, during module string bonding, the increased height and width of the antenna structure significantly increases its cross-sectional area. When the solder ribbon, cell, and paste are fused together, there is sufficient silver paste in the transverse direction of the antenna structure for the solder ribbon to melt or absorb, effectively preventing solder joint breaks. Attached Figure Description
[0028] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0029] Figure 1 This is a schematic diagram of the main grid electrode structure in an embodiment of the present invention;
[0030] Figure 2 This is a schematic diagram of the sub-gate electrode in an embodiment of the present invention;
[0031] Figure 3 This is a schematic diagram of the electrode structure in an embodiment of the present invention;
[0032] Figure 4 This is a schematic diagram of the exploded structure of the antennae in an embodiment of this utility model;
[0033] Figure 5 This is a schematic diagram of the antenna structure in an embodiment of the present invention.
[0034] Explanation of reference numerals in the attached figures:
[0035] 1-Main gate line; 2-Pad; 3-Fish-shaped connection line; 4-Sub-gate line; 5-Border line; 6-Third antenna; 7-First antenna; 71-Main body area; 72-Gradient area; 73-Hole hole; 8-Second antenna; 81-Solid area; 82-Transition area. Detailed Implementation
[0036] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.
[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0038] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0039] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0040] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0041] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0042] Please see Figures 1 to 5 This application provides an embodiment of an electrode structure for a solar cell, including a main grid electrode, a sub-grid electrode, and several antenna structures. The main grid electrode includes several main grid lines 1, several pads 2, and several fork-shaped connecting lines 3. The main grid lines 1 are spaced apart along a first direction and extend along a second direction, wherein the first direction intersects the second direction, and optionally the first direction is perpendicular to the second direction. Pads 2 are provided at both ends and in the portion between the two ends of the main grid lines 1, and the pads 2 at both ends of the main grid lines 1 are connected to the fork-shaped connecting lines 3. The sub-grid electrode includes several sub-grid lines 4 and a border line 5 located around the sub-grid lines 4. The sub-grid lines 4 are spaced apart along the second direction and extend along the first direction. Some sub-grid lines 4 intersect and overlap with the several main grid lines 1, optionally some sub-grid lines 4 intersect perpendicularly with the several main grid lines 1. The border line 5 is used to connect the several sub-grid lines 4.
[0043] It is worth noting that the pad 2 intersects with the corresponding sub-gate line 4. The sub-gate line 4 intersecting with the pad 2 is a discontinuous gate line, with the discontinuity located within the corresponding pad 2, and the discontinuous end of the discontinuous gate line inserted into the corresponding pad 2. The sub-gate electrode also includes several third antennas 6, which are located at the intersection of the sub-gate line 4 and the corresponding harpoon-shaped connecting line 3. This is a conventional structure and will not be described in detail here.
[0044] Several antenna structures are disposed at the intersection of the main gate line 1 and the sub-gate line 4. The length direction of the antenna structure is the same as the extension direction of the sub-gate line 4. The antenna structure includes a first antenna 7 and a second antenna 8. The second antenna 8 is superimposed on the first antenna 7 and in contact with the first antenna 7. The width of the second antenna 8 is smaller than the width of the first antenna 7. In some optional embodiments, the main gate electrode and the first antenna 7 are printed simultaneously, and the sub-gate electrode and the second antenna 8 are printed simultaneously.
[0045] By printing the antenna structure in two stages, the width and height of the antenna structure are increased. Printing the first antenna 7 simultaneously with the main grid electrode effectively controls the wet weight of the sub-grid electrode and the second antenna 8, avoiding the problem of excessive wet weight caused by increasing the antenna width and height during the second printing in existing technologies. This method reduces silver paste usage while avoiding paste waste due to increased wet weight. Furthermore, during module string bonding, the increased height and width of the antenna structure significantly enlarges its cross-sectional area. This ensures sufficient silver paste in the transverse direction of the antenna structure for melting or adsorption of the solder strip when it fuses with the cell and paste, effectively preventing solder joint breaks.
[0046] It is worth noting that the electrode structure can be a front electrode, where the fork-shaped connecting line 3 of the front electrode can be called the front fork-shaped connecting line 3, the main grid line 1 of the front electrode can be called the front main grid line 1, and the sub-grid line 4 of the front electrode can be called the front sub-grid line 4; the electrode structure can also be a back electrode, where the fork-shaped connecting line 3 of the back electrode can be called the back fork-shaped connecting line 3, the main grid line 1 of the back electrode can be called the back main grid line 1, and the sub-grid line 4 of the back electrode can be called the back sub-grid line 4.
[0047] In this embodiment, the first antenna 7 includes a main body region 71 and gradient regions 72 located at both ends of the main body region 71 along its length. The width of the gradient regions 72 gradually decreases from the main body region 71 away from it. The main body region 71 is provided with a plurality of perforated holes 73 at intervals along its length. Since the antenna structure is printed in two stages, the first antenna 7 is added in the first printing, resulting in an increase in wet weight. Therefore, the first antenna 7 is designed as a perforated structure. This design can effectively reduce wet weight while maintaining the stability and functionality of the antenna, avoiding the waste of paste caused by excessive wet weight, and reducing the amount of silver paste used while improving the overall performance of the antenna.
[0048] The second antenna 8 includes a solid region 81 and transition regions 82 located at both ends of the solid region 81 along its length. The width of the transition regions 82 gradually decreases from the solid region 81 toward the distance from the solid region 81.
[0049] In some embodiments, the length of the second antenna 8 is greater than the length of the first antenna 7, and the length of the transition region 82 is greater than the length of the gradient region 72. Specifically, the length of the main body region 71 is 0.81±0.05mm, and the width is 0.09±0.01mm; the length of the solid region 81 is 0.8±0.05mm, and the width is 0.04±0.01mm; the length of the gradient region 72 is 0.045±0.005mm, and the width decreases from 0.09±0.01mm to 0.033±0.005mm; the length of the transition region 82 is 0.16±0.02mm, and the width decreases from 0.04±0.01mm to 0.022±0.005mm.
[0050] In some embodiments, a plurality of perforated holes 73 are arranged at equal intervals, and the distance between adjacent perforated holes 73 is 0.015±0.005mm.
[0051] In some embodiments, the perforated hole 73 has a rectangular structure, and the width of the second antenna 8 is smaller than the width of the perforated hole 73. The length of the perforated hole 73 is 0.087±0.01mm, and the width is 0.06±0.01mm. Admittedly, in other embodiments, the perforated hole 73 may also be configured with other shapes. This application does not specifically limit the shape and size of the perforated hole 73, and adjustments can be made according to design requirements.
[0052] In some embodiments, the height of the antennal structure is greater than 7 μm, and the height of the second antenna 8 is greater than the height of the first antenna 7. Specifically, the height of the first antenna 7 is 1.5 μm to 2.5 μm, and the height of the second antenna 8 is 5 μm to 7 μm.
[0053] An embodiment of this utility model also provides a solar cell including a cell body and an electrode structure disposed on the surface of the cell body. The electrode structure is the same as the electrode structure described above, and can be found in the foregoing content for details, which will not be repeated here.
[0054] One embodiment of this utility model also provides a screen printing plate for printing the front and back electrodes of a solar cell. The screen printing plate has a printed pattern, the printed pattern of which is consistent with the shape of the electrode structure described above. For details, please refer to the foregoing description, which will not be repeated here.
[0055] Finally, it should be noted that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An electrode structure for a solar cell, characterized in that, include: The main gate electrode includes a plurality of main gate lines, a plurality of pads, and a plurality of harpoon-shaped connecting lines. The pads are provided on both ends of the main gate lines and on the portion between the two ends. The pads at both ends of the main gate lines are connected to the harpoon-shaped connecting lines. The sub-gate electrode includes a plurality of sub-gate lines, some of which intersect and overlap with a plurality of the main gate lines; Several antenna structures are disposed at the intersection of the main grid line and the sub-grid line. The length direction of the antenna structure is the same as the extension direction of the sub-grid line. The antenna structure includes a first antenna and a second antenna. The second antenna is superimposed on the first antenna and in contact with the first antenna. The width of the second antenna is smaller than the width of the first antenna.
2. The electrode structure of the solar cell as described in claim 1, characterized in that, The first antenna includes a main body area and gradient areas located at both ends of the main body area along its length. The width of the gradient areas gradually decreases from the main body area away from the main body area. The main body area is provided with a plurality of perforated holes at intervals along its length. The second antenna includes a solid region and transition regions located at both ends of the solid region along its length, the width of which gradually decreases from the solid region toward the distance from the solid region.
3. The electrode structure of the solar cell as described in claim 2, characterized in that, The length of the second antenna is greater than the length of the first antenna, and the length of the transition zone is greater than the length of the gradient zone.
4. The electrode structure of the solar cell as described in claim 3, characterized in that, The length of the main body area is 0.81±0.05mm, and the width is 0.09±0.01mm; The length of the solid region is 0.8±0.05mm, and the width is 0.04±0.01mm; The length of the gradient zone is 0.045±0.005mm, and the width decreases from 0.09±0.01mm to 0.033±0.005mm; The length of the transition zone is 0.16±0.02mm, and the width is reduced from 0.04±0.01mm to 0.022±0.005mm.
5. The electrode structure of the solar cell as described in claim 2, characterized in that, The perforation has a rectangular structure, and the width of the second antenna is smaller than the width of the perforation.
6. The electrode structure of the solar cell as described in claim 1, characterized in that, The height of the antennal structure is greater than 7 μm, and the height of the second antenna is greater than the height of the first antenna.
7. The electrode structure of the solar cell as described in claim 6, characterized in that, The height of the first antenna is 1.5μm to 2.5μm, and the height of the second antenna is 5μm to 7μm.
8. The electrode structure of the solar cell as described in claim 2, characterized in that, The perforated holes are arranged at equal intervals, and the distance between adjacent perforated holes is 0.015±0.005mm.
9. A solar cell, characterized in that, include: The battery cell itself; The electrode structure as described in any one of claims 1 to 8 is disposed on the surface of the battery cell body.
10. A screen printing plate, characterized in that, It has a printed pattern, the printed pattern being consistent with the shape of the electrode structure according to any one of claims 1 to 8.