Solder strip and solar cell
Patent Information
- Application Number
- CN202521739160.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-15
- Publication Date
- 2026-08-21
- Estimated Expiration
- 2035-08-15
AI Technical Summary
[0005]为了解决现有技术中的上述至少一个问题，即为了解决通过缩小电池片的pad点的尺寸来降低银浆单耗，会影响电池片的焊接效果和可靠性的问题
[0017]在采用上述技术方案的前提下，本申请对焊带进行了差异化设计，焊带中用于与pad点连接的压扁区域被压扁呈扁平状，焊接时扁平状的压扁区域与pad点之间的接触面积更大。焊带和pad点之间的接触面积增大有利于改善焊接拉力，避免在温度循环测试后焊带与电池片脱焊，有利于提高电池片的焊接效果和可靠性。此外，压扁区域的非压扁面更扁平与pad点之间的接触更好。
Smart Images
Figure CN224670201U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of solar cell technology, specifically to a solder strip and a solar cell. Background Technology
[0002] Silver paste has become one of the main raw materials for solar cells due to its excellent rheological and electrical properties. With the development of high-efficiency cell technologies (such as Topcon and heterojunction cells), the consumption of silver paste per unit continues to increase, leading to an increase in the cost of solar cells.
[0003] Related technologies reduce silver paste consumption by shrinking the size of the pad points on the solar cells. However, shrinking the pad point size reduces the contact area between the traditional round wire solder and the pad point, resulting in lower welding tensile strength. This makes the cells more susceptible to desoldering and failure after being subjected to thermal shock during temperature cycling tests, thus affecting the welding effect and reliability of the solar cells.
[0004] Accordingly, a new technical solution is needed in this field to solve the above problems. Utility Model Content
[0005] In order to solve at least one of the above-mentioned problems in the prior art, namely, to solve the problem that reducing the silver paste consumption by shrinking the size of the pad point of the solar cell will affect the welding effect and reliability of the solar cell.
[0006] In a first aspect, this application provides a solder strip for spot welding to a pad of a battery cell. The solder strip includes a flattened region and a non-flattened region located between the flattened regions. The thickness of the flattened region is less than the thickness of the non-flattened region, and the width of the flattened region is greater than the width of the non-flattened region. The flattened region includes a flattened surface and a non-flattened surface. The flattened surface is concave, and the non-flattened surface is used for spot welding to the pad.
[0007] In some embodiments, the thickness of the flattened region is 18% to 44% of the thickness of the non-flattened region.
[0008] In some embodiments, the length of the flattened region is 125% to 188% of the length of the pad point, wherein both the length of the flattened region and the length of the pad point extend along the axial direction of the solder strip.
[0009] In some embodiments, the width of the flattened region is 100% to 250% of the width of the pad point, wherein both the width of the flattened region and the width of the pad point extend along an axial direction perpendicular to the solder strip.
[0010] In some embodiments, the width of the flattened region is 290% to 750% of the width of the non-flattened region.
[0011] In some embodiments, the pad points include end pad points and non-end pad points located between the end pad points, and the flattened region includes an end flattened region and a non-end flattened region. The end flattened region is used for welding to the end pad points, and the non-end flattened region is used for welding to the non-end pad points, wherein the area of the end flattened region is larger than the area of the non-end flattened region.
[0012] In some embodiments, the shape of the flattened region is the same as the shape of the pad point.
[0013] In some embodiments, the solder strip includes a first connecting segment, wherein the flattened region located in the first connecting segment is used for spot welding to the pad on the front side of the cell; and / or the solder strip includes a second connecting segment, wherein the flattened region located in the second connecting segment is used for spot welding to the pad on the back side of the cell.
[0014] In some embodiments, where the solder strip includes the first connecting segment and the second connecting segment, the non-flattened surface of the first connecting segment has an opposite orientation to the non-flattened surface of the second connecting segment.
[0015] In some embodiments, the flattened area corresponds one-to-one with the pad point.
[0016] Secondly, this application provides a solar cell comprising a plurality of cells connected by the aforementioned solder strips.
[0017] Based on the above technical solution, this application features a differentiated design for the solder strip. The flattened area of the solder strip used for connection with the pad point is flattened into a flat shape, resulting in a larger contact area between the flattened area and the pad point during welding. This increased contact area improves welding tensile strength, prevents the solder strip from detaching from the cell after temperature cycling testing, and enhances the welding effect and reliability of the cell. Furthermore, the flatter, non-flattened surface of the flattened area provides even better contact with the pad point. Attached Figure Description
[0018] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which:
[0019] Figure 1 This is a top view of the solder strip structure in this application;
[0020] Figure 2This is a schematic diagram of the structure of the battery cell in this application;
[0021] Figure 3 This is a schematic diagram of the side structure of a welding strip in this application;
[0022] Figure 4 yes Figure 1 A schematic diagram of the side structure of the welding strip;
[0023] Figure 5 This is a schematic diagram of the side structure of another type of solder strip in this application;
[0024] Figure 6 This is a schematic diagram of the welding structure between the welding strip and the battery cell.
[0025] Figure label:
[0026] 1. Welding strip; 101. Flattened area; 1011. Flattened surface; 1012. Unflattened surface; 1013. End flattened area; 1014. Non-end flattened area; 102. Unflattened area; 103. First connecting section; 104. Second connecting section;
[0027] 2. Pad point; 201. End pad point; 202. Non-end pad point. Detailed Implementation
[0028] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely for explaining the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios. Such changes in application scenarios do not deviate from the basic principles of this application and fall within the scope of protection of this application.
[0029] In the embodiments of this application, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly for better describing the embodiments of this application and their implementations, 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. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" 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 according to the specific circumstances.
[0030] It should be noted that, in the description of this preferred embodiment, unless otherwise explicitly specified and limited, the terms "connected" and "connected" should be interpreted broadly. For example, they can refer to mechanical connections or electrical connections, direct connections or indirect connections through an intermediate medium, or connections within two components. These should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only, and those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.
[0031] Silver paste has become one of the main raw materials for solar cells due to its excellent rheological and electrical properties. With the development of high-efficiency cell technologies (such as Topcon and heterojunction cells), the consumption of silver paste per unit continues to increase, leading to an increase in the cost of solar cells.
[0032] Related technologies reduce silver paste consumption by shrinking the size of the pad points on the solar cells. However, shrinking the pad point size reduces the contact area between the traditional round wire solder and the pad point, resulting in lower welding tensile strength. This makes the cells more susceptible to desoldering and failure after being subjected to thermal shock during temperature cycling tests, thus affecting the welding effect and reliability of the solar cells.
[0033] Among them, silver paste consumption refers to the amount of silver paste required to produce a unit area or a unit output.
[0034] In a solar cell, the cell comprises multiple main grid lines, which are conductive metal lines printed on the cell's surface. These lines are responsible for collecting the current generated inside the cell. Each main grid line has multiple pad points. Pad points are metal contact points on the cell; their main function is to connect with solder ribbons to facilitate current conduction. Solder ribbons are used to connect the main grid lines of each cell, linking the currents of multiple cells in series or parallel to form a complete circuit, ensuring smooth current transmission within the cell.
[0035] Temperature cycling testing, also known as TC testing, is used to evaluate the temperature characteristics and performance of solar cells. TC testing simulates the temperature variations that may be encountered in real-world use by exposing the solar cells to alternating high and low temperature environments, in order to assess the performance stability and reliability of the solar cells under these conditions.
[0036] This application provides a solder ribbon and a solar cell that can increase the contact area between the solder ribbon and the pad point, which is beneficial to improving the welding effect and reliability of the solar cell.
[0037] In one aspect, this application provides a solder strip.
[0038] Figure 1 This is a schematic diagram of the structure of solder strip 1. Figure 2This is a schematic diagram of the battery cell structure, combined with... Figure 1 and Figure 2 As shown, the solder strip 1 is used for soldering to the battery cell, which includes multiple pad points 2.
[0039] Figure 3 yes Figure 1 A schematic diagram of the side structure of the welding strip, combined with... Figure 3 As shown, the solder strip 1 includes a flattened region 101 and a non-flattened region 102 located between the flattened regions 101. The flattened region 101 is used to connect with the pad point 2 for bonding. Figure 1 As shown, the thickness of the flattened region 101 is less than the thickness of the non-flattened region 102, and the width of the flattened region 101 is greater than the width of the non-flattened region 102.
[0040] Among them, combined Figure 3 As shown, the flattened region 101 includes a flattened surface 1011 and a non-flattened surface 1012. The flattened surface 1011 is concave, and the non-flattened surface 1012 is used to connect with pad point 2.
[0041] Based on the above technical solution, this application features a differentiated design for the solder strip 1. The flattened area 101 of the solder strip 1, used for connection with the pad point 2, is flattened into a flat shape, resulting in a larger contact area between the flattened area 101 and the pad point 2 during welding. This increased contact area between the solder strip 1 and the pad point 2 improves welding tensile strength, prevents the solder strip 1 from detaching from the battery cell after temperature cycling testing, and enhances the welding effect and reliability of the battery cell. Furthermore, the non-flattened surface 1012 of the flattened area 101 is flatter and provides better contact with the pad point 2.
[0042] In some embodiments, the thickness of the flattened region 101 is 18% to 44% of the thickness of the non-flattened region 102. For example, the thickness of the flattened region 101 is 18%, 20%, 25%, 27%, 30%, 32%, 35%, 37%, 39%, 40%, 42%, or 44% of the thickness of the non-flattened region 102.
[0043] By limiting the thickness of the flattened region 101 within the aforementioned range, the area of the flattened region 101 can be appropriately increased, thereby increasing the welding area between the solder strip 1 and the pad point 2, which is beneficial to ensuring the welding effect between the solder strip 1 and the battery cell; at the same time, it can also ensure that the flattened region 101 maintains a moderate thickness, so that the flattened region 101 can provide sufficient metal filling, ensuring the stability of the welding with the pad point, and avoiding problems such as incomplete welding or desoldering due to insufficient solder.
[0044] In some embodiments, the length of the flattened region 101 is 125% to 188% of the length of the pad point 2, wherein both the length of the flattened region 101 and the length of the pad point 2 extend along the axial direction of the solder strip 1. For example, the length of the flattened region 101 can be 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 187.5%, or 188% of the length of the pad point 2. By making the length of the flattened region 101 greater than 125% of the length of the pad point 2, the flattened region 101 can cover the length direction of the pad point 2, which is beneficial to improving the welding effect between the flattened region 101 and the pad point 2. In addition, if the length of the flattened region 101 does not exceed 188% of the length of the pad point 2, the obstruction of the battery cell by the flattened region 101 can be reduced, thus reducing the impact on battery efficiency.
[0045] In some embodiments, the width of the flattened region 101 is 100% to 250% of the width of the pad point 2, wherein both the width of the flattened region 101 and the width of the pad point 2 extend along an axial direction perpendicular to the solder strip 1. For example, the width of the flattened region 101 can be 100%, 120%, 130%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 180%, 200%, 230%, or 250% of the width of the pad point 2. By making the width of the flattened region 101 greater than 100% of the width of the pad point 2, the flattened region 101 can cover the width direction of the pad point 2, which is beneficial to improving the welding effect between the flattened region 101 and the pad point 2. In addition, if the width of the flattened region 101 does not exceed 250% of the width of the pad point 2, the obstruction of the battery cell by the flattened region 101 can be reduced, thus reducing the impact on battery efficiency.
[0046] In some embodiments, the width of the flattened region 101 is 290% to 750% of the width of the non-flattened region 102. For example, the width of the flattened region 101 is 290%, 300%, 330%, 360%, 400%, 450%, 500%, 550%, 600%, 670%, 700%, 730%, or 750% of the width of the non-flattened region 102. By limiting the width of the flattened region 101 to the above range, the area of the flattened region 101 can be appropriately increased, thereby increasing the welding area between the solder ribbon 1 and the pad point 2, which is beneficial to ensuring the welding effect between the solder ribbon 1 and the battery cell; at the same time, it can also prevent the flattened region 101 from being excessively extended, which is beneficial to ensuring the stability of the welding with the pad point and avoiding problems such as incomplete soldering or desoldering due to insufficient solder.
[0047] In some embodiments, combined with Figure 2As shown, pad point 2 includes end pad point 201 and non-end pad point 202 located between end pad points 201. The end pad point 201 is located at the end of the main grid line, and the non-end pad point 202 is located between the end pad points 201.
[0048] The flattened region 101 includes an end flattened region 1013 and a non-end flattened region 1014. The end flattened region 1013 is used to connect with the end pad point 201, and the non-end flattened region 1014 is used to connect with the non-end pad point 202. The area of the end flattened region 1013 is larger than the area of the non-end flattened region 1014.
[0049] The end pad point 201 experiences greater stress during temperature cycling tests, making it more prone to issues such as desoldering. Based on the aforementioned technical solution, this application employs a differentiated design for the flattened region 101, making the area of the end flattened region 1013 larger than the area of the non-end flattened region 1014. This increases the contact area between the end flattened region 1013 and the end pad point 201, resulting in a stronger weld between them. This reduces the risk of desoldering of the end pad point 201 after temperature cycling tests, thus improving the reliability of the solar cell.
[0050] In some embodiments, the shape of the flattened region 101 is the same as the shape of the pad point 2. This helps to improve the matching degree between the flattened region 101 and the pad point, maximize the contact area, and at the same time, the consistent shape can make the welding stress evenly distributed and reduce stress concentration.
[0051] For example, the shape of pad point 2 is approximately rhomboid or approximately elliptical, and the corresponding flattened region 101 is approximately rhomboid or approximately elliptical.
[0052] In some embodiments, combined with Figure 3 , Figure 4 and Figure 5 As shown, the solder strip 1 includes a first connecting segment 103 and / or a second connecting segment 104. That is, the solder strip 1 has three possible configurations: as follows... Figure 3 As shown, the solder strip 1 includes both the first connecting segment 103 and the second connecting segment 104; or as shown... Figure 4 As shown, solder strip 1 only includes the first connecting segment 103; or as... Figure 5 As shown, the solder strip 1 only includes the second connecting section 104. The flattened area 101 located in the first connecting section 103 is used for welding to the front side of the battery cell, and the flattened area 101 located in the second connecting section 104 is used for welding to the back side of the battery cell.
[0053] In some embodiments, combined with Figure 3As shown, when the solder strip 1 includes both a first connecting segment 103 and a second connecting segment 104, the non-flattened surface 1012 of the flattened region 101 located in the first connecting segment 103 and the non-flattened surface 1012 of the flattened region 101 located in the second connecting segment 104 have opposite orientations. This ensures that the non-flattened surface 1012 of the solder strip 1 is always welded to the pad point 2. The flatter non-flattened surface 1012 of the flattened region 101 has better contact with the pad point 2, which is beneficial to improving the strength of the weld between the solder strip 1 and the battery cell.
[0054] In some embodiments, Figure 6 This is a schematic diagram of the connection between the solder ribbon and the solar cell, combined with... Figure 6 As shown, the flattened area 101 corresponds one-to-one with pad point 2. This facilitates the connection between the solder ribbon 1 and the battery cell.
[0055] Secondly, this application provides a solar cell.
[0056] The solar cell provided in this application includes multiple cells, which are connected by the solder strip 1 of any of the above embodiments.
[0057] Based on the above technical solution, the solder ribbon 1 of the solar cell in this application features a differentiated design. The flattened area 101 of the solder ribbon 1, used for connection with the pad point 2, is flattened into a flat shape, resulting in a larger contact area between the flattened area 101 and the pad point 2 during welding. This increased contact area between the solder ribbon 1 and the pad point 2 improves welding tensile strength, prevents the solder ribbon 1 from detaching from the solar cell after temperature cycling testing, and ultimately enhances the welding effect and reliability of the solar cell.
[0058] The solar cell provided in this application includes multiple main busbars, each with multiple pad points. A solder ribbon covers and is soldered onto multiple pad points of one main busbar in the solar cell, or it can extend to multiple pad points of one main busbar in another solar cell.
[0059] The solar cell also includes multiple sub-busbars, which intersect with multiple main busbars. Each intersection of a sub-busbar and a main busbar features a centipede-like branch. By incorporating this centipede-like branch at the intersection of the main and sub-busbars, the contact area between the intersection and the cell surface is increased. This allows for more efficient current collection and conduction, improving current collection efficiency. Furthermore, the centipede-like branch increases the connection points between the main and sub-busbars and the cell, contributing to improved overall structural stability of the solar cell.
[0060] The technical solutions of this application have been described in conjunction with the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions resulting from these changes or substitutions will all fall within the scope of protection of this application.
Claims
1. A welding strip (1) for welding to a pad point (2) of a battery cell, characterized in that, The welding strip (1) includes a flattened region (101) and a non-flattened region (102) located between the flattened region (101), wherein the thickness of the flattened region (101) is less than the thickness of the non-flattened region (102), and the width of the flattened region (101) is greater than the width of the non-flattened region (102). The flattened area (101) includes a flattened surface (1011) and a non-flattened surface (1012). The flattened surface (1011) is concave, and the non-flattened surface (1012) is used to weld to the pad point (2).
2. The welding strip (1) according to claim 1, characterized in that, The thickness of the flattened region (101) is 18% to 44% of the thickness of the non-flattened region (102).
3. The welding strip (1) according to claim 1, characterized in that, The length of the flattened region (101) is 125% to 188% of the length of the pad point (2), wherein the length of the flattened region (101) and the length of the pad point (2) both extend along the axial direction of the welding strip (1).
4. The welding strip (1) according to claim 1, characterized in that, The width of the flattened area (101) is 100% to 250% of the width of the pad point (2), wherein the width of the flattened area (101) and the width of the pad point (2) both extend in a direction perpendicular to the axial direction of the solder strip (1).
5. The welding strip (1) according to claim 1, characterized in that, The width of the flattened region (101) is 290% to 750% of the width of the non-flattened region (102).
6. The welding strip (1) according to any one of claims 1 to 5, characterized in that, The pad point (2) includes an end pad point (201) and a non-end pad point (202) located between the end pad points (201). The flattened region (101) includes an end flattened region (1013) and a non-end flattened region (1014). The end flattened region (1013) is used to weld to the end pad point (201), and the non-end flattened region (1014) is used to weld to the non-end pad point (202). The area of the end flattened region (1013) is larger than the area of the non-end flattened region (1014).
7. The welding strip (1) according to any one of claims 1 to 5, characterized in that, The shape of the flattened region (101) is the same as the shape of the pad point (2).
8. The welding strip (1) according to any one of claims 1 to 5, characterized in that, The solder strip (1) includes a first connecting segment (103), wherein the flattened area (101) located in the first connecting segment (103) is used for welding to the pad point (2) on the front side of the battery cell; and / or The solder strip (1) includes a second connecting section (104), wherein the flattened area (101) located in the second connecting section (104) is used for soldering to the pad point (2) on the back of the battery cell.
9. The welding strip (1) according to claim 8, characterized in that, In the case where the solder strip (1) includes the first connecting segment (103) and the second connecting segment (104), the non-flattened surface (1012) located in the first connecting segment (103) has the opposite orientation to the non-flattened surface (1012) located in the second connecting segment (104).
10. A solar cell, characterized in that, The solar cell comprises a plurality of cells connected by a solder strip (1) according to any one of claims 1 to 9.