Welding strip fasteners and photovoltaic cell strings

Abstract

This utility model discloses a solder ribbon fixing component and a photovoltaic cell string. The solder ribbon fixing component is used to fix the solder ribbon to the cell before soldering it to the cell. The solder ribbon fixing component includes: a substrate and a plurality of first adhesive layers and a plurality of second adhesive layers disposed on a first surface of the substrate facing the cell. The first adhesive layers are spaced apart on both sides of the substrate in the width direction, and the second adhesive layers are located between the two first adhesive layers and spaced apart along the length direction of the substrate. The first adhesive layers are bonded to the cell, and the second adhesive layers are bonded to the solder ribbon, with the solder ribbon located between the two first adhesive layers. By setting the first adhesive layers on both sides of the substrate in the width direction, the solder ribbon is arranged between the first adhesive layers, effectively preventing free solder generated during lamination soldering from penetrating into the cell area outside the adhesive layers.

Description

Technical Field

[0001] This utility model relates to a welding strip fastener and a photovoltaic cell string. Background Technology

[0002] Currently, gridless back-contact photovoltaic (PV) cells show great promise as a new type of cell. These cells feature alternating positive and negative fine grid lines on the back, with solder paste and insulating adhesive printed alternately on these lines. Solder ribbons selectively connect the positive and negative grid lines using the solder paste and insulating adhesive. However, because gridless back-contact PV cells only have solder ribbons soldered on one side, this can lead to issues such as cell warping. To avoid this, low-temperature soldering is often used. This involves pre-fixing the solder ribbons to the cells using tape or a film, and then bonding them together using a lamination process. However, because the solder paste printing height is higher than the insulating adhesive printing height, air pockets can easily form beneath the solder ribbons when using fasteners such as tape to fix them. Molten solder can then migrate through these air pockets, potentially causing short circuits in the module. Utility Model Content

[0003] In view of this, the present invention provides a solder ribbon fixing component and a photovoltaic cell string. By setting a first adhesive layer on both sides of the substrate in the width direction, the solder ribbon is arranged between the first adhesive layers, which effectively prevents free tin generated by lamination welding from penetrating into the cell area outside the adhesive layer, thereby preventing short circuit of the cell module.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] This invention provides a welding strip fixing component, which is used to fix the welding strip to the battery cell before welding the welding strip to the battery cell.

[0006] The welding strip fastener includes: a substrate and a plurality of first adhesive layers and a plurality of second adhesive layers disposed on a first surface of the substrate facing the battery cell.

[0007] The first adhesive layers are spaced apart on both sides of the substrate in the width direction, and the second adhesive layers are located between the first adhesive layers on both sides and are spaced apart along the length direction of the substrate.

[0008] The first adhesive layer is bonded to the battery cell, the second adhesive layer is bonded to the solder ribbon, and the solder ribbon is located between the first adhesive layers on both sides.

[0009] This utility model also provides a photovoltaic cell string, including: multiple solar cells, a solder strip electrically connecting two adjacent solar cells, and a solder strip fixing component as described above.

[0010] The back surface of the solar cell has positive and negative grid lines, which extend along the width direction of the substrate and are spaced apart along the length direction of the substrate.

[0011] Soldering material and insulating material are printed alternately on the positive and negative grid lines, with the soldering material on the positive grid line aligned with the insulating material on the negative grid line, and vice versa.

[0012] The solder ribbon extends along the length of the substrate and covers the welding material on the positive electrode grid line and the insulating material on the negative electrode grid line of the solar cell, or covers the insulating material on the positive electrode grid line and the welding material on the negative electrode grid line of the solar cell.

[0013] The ribbon fastener covers the ribbon to secure it to the cell before welding it to the cell.

[0014] The above-mentioned utility model has the following advantages or beneficial effects:

[0015] The solder ribbon fixing component and photovoltaic cell string provided in this embodiment of the invention, by setting a first adhesive layer on both sides of the substrate in the width direction, allows the solder ribbon to be arranged between the first adhesive layers, which acts as a barrier against the welding material, effectively preventing free solder generated during lamination welding from seeping into the cell area outside the adhesive layer, thereby preventing short circuits in the cell module. Furthermore, by setting a second adhesive layer that bonds to the solder ribbon, the solder ribbon can be effectively fixed, preventing displacement of the solder ribbon, and ensuring a stable fixation and reliable electrical connection between the solder ribbon and the cell. Attached Figure Description

[0016] Figure 1 A bottom view of the welding strip fastener according to an embodiment of the present invention is shown;

[0017] Figure 2 Show along Figure 1 A cross-sectional view of line AA;

[0018] Figure 3 Show along Figure 1 A cross-sectional view of the BB line;

[0019] Figure 4 Show along Figure 1 A cross-sectional view of the CC line;

[0020] Figure 5 A top view of the welding strip fastener according to an embodiment of the present invention is shown;

[0021] Figure 6 A top view of one of the cells in a photovoltaic cell string according to an embodiment of the present invention is shown;

[0022] Figure 7 Show along Figure 6 A cross-sectional view of the DD line;

[0023] Figure 8 Show along Figure 6 A cross-sectional view of the EE line;

[0024] Figure 9 A top view of one of the cells in a gridless back-contact photovoltaic cell string using tape to fix the welding strip in the prior art;

[0025] Figure 10 Show along Figure 9 A cross-sectional view of the FF line;

[0026] Figure 11 The diagram illustrates how the welding strip slips when it is fixed with adhesive tape in the prior art.

[0027] The attached figures are labeled as follows:

[0028] 1-Photovoltaic cell string; 10-Solder ribbon fastener; 100-Substrate; 101-First adhesive layer; 102-Second adhesive layer; 103-Third adhesive layer; 104-Vent hole; 105-Groove; 106-First surface; 107-Second surface; 20-Solder ribbon; 30-Cell; 301-First grid line; 302-Second grid line; 303-Insulating material; 303a-Insulating adhesive; 304-Welding material; 304a-Solder paste; 40-Tape; 50-Film; X-Length direction; Y-Width direction; Z-Height direction. Detailed Implementation

[0029] To facilitate and clearly describe the welding strip fastener and photovoltaic cell string of this utility model, exemplary embodiments of this utility model are described below with reference to the accompanying drawings, including various details of the embodiments of this utility model to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this utility model. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0030] First, the back-contact photovoltaic (PV) cell string without a main grid is described. The cell forms positive and negative electrode regions by doping with different dopants. Fine positive grid lines are printed in the positive electrode region, and fine negative grid lines are printed in the negative electrode region. These grid lines are used to collect the current generated by the cell. Cells with a main grid electrically connect the main grid to the fine grid lines, and then connect the solder ribbon to the main grid. Cells without a main grid directly connect the solder ribbon to the fine grid lines. Figure 9 and Figure 10As shown, positive and negative fine grid lines 301 and 302 are alternately arranged on the back of the gridless back-contact photovoltaic cell, and solder paste 304a and insulating adhesive 303a are alternately printed on the fine grid lines. The solder ribbon 20 selectively connects the positive and negative fine grid lines 301 and 302 through the solder paste 304a and insulating adhesive 303a. Since the gridless back-contact photovoltaic cell only has the solder ribbon 20 soldered on one side, it can cause problems such as cell warping. To avoid these problems, a low-temperature soldering method is often used, that is, the solder ribbon is pre-fixed to the cell with tape 40, and then the solder ribbon is soldered to the cell using a lamination process. However, since the printing height of the solder paste 304a is higher than that of the insulating adhesive 303a, air cavities are easily formed under the solder ribbon when the fixing component of tape 40 is used to fix the solder ribbon. The molten solder will wander around along the air cavities, which can easily lead to short circuits in the cell module.

[0031] To address the problem of molten solder becoming detached due to the use of adhesive tape to fix solder ribbons in existing technologies, this invention provides a solder ribbon fixing component and a photovoltaic cell string.

[0032] Figure 1 A bottom view of the welding strip fastener according to an embodiment of the present invention is shown; Figure 2 Show along Figure 1 A cross-sectional view of line AA; Figure 3 Show along Figure 1 A cross-sectional view of the BB line;

[0033] Figure 4 Show along Figure 1 A cross-sectional view of the CC line; Figure 5 A top view of the welding strip fastener according to an embodiment of the present invention is shown; Figure 6 A top view of one of the cells in a photovoltaic cell string according to an embodiment of the present invention is shown; Figure 7 Show along Figure 6 A cross-sectional view of the DD line; Figure 8 Show along Figure 6 A cross-sectional view of the EE line.

[0034] This utility model provides a welding ribbon fixing component for fixing the welding ribbon to the battery cell before welding the welding ribbon to the battery cell. For example... Figures 1 to 8As shown, the solder ribbon fixing member 10 includes: a substrate 100 and a plurality of first adhesive layers 101 and a plurality of second adhesive layers 102 disposed on a first surface 106 of the substrate 100 facing the battery cell 30. The first adhesive layers 101 are spaced apart on both sides of the substrate 100 in the width direction Y, and the second adhesive layers 102 are located between the two sides of the first adhesive layers 101 and spaced apart along the length direction X of the substrate 100. The first adhesive layers 101 are bonded to the battery cell 30, and the second adhesive layers 102 are bonded to the solder ribbon 20, with the solder ribbon 20 located between the two sides of the first adhesive layers 101.

[0035] The solder ribbon fixing component 10 provided in this embodiment of the utility model, by providing first adhesive layers 101 on both sides of the substrate 100 in the width direction Y, arranges the solder ribbon 20 between the first adhesive layers 101, which acts as a barrier for the welding material, effectively preventing free solder generated by lamination welding from seeping into the battery area outside the first adhesive layers 101, thereby preventing short circuits in the battery assembly. In addition, by providing a second adhesive layer 102 that is bonded to the solder ribbon 20, the solder ribbon 20 can be effectively fixed, preventing the position of the solder ribbon 20 from shifting, so that the solder ribbon 20 and the battery cell 30 can be stably fixed and reliably electrically connected.

[0036] The substrate 100 is, for example, one of polyester tape substrate, polyethylene tape substrate, polyvinyl chloride tape substrate, and glass fiber substrate.

[0037] In addition, such as Figure 11 As shown, in the existing technology of using tape to fix the welding strip in a gridless back contact photovoltaic cell string, the substrate of tape 40 is PET (polyethylene terephthalate) resin. The adhesion strength between tape 40 and the upper adhesive film 50 is limited. Therefore, during the lamination process, adhesive film 50 is prone to slippage from tape 40, which affects the lamination accuracy of the cell module.

[0038] In the welding strip fixing member 10 of this utility model embodiment, such as Figure 2 As shown, a third adhesive layer 103 is provided on the second surface 107 of the substrate 100 opposite to the first surface 106.

[0039] By providing a third adhesive layer 103 on the second surface 107 of the substrate 100, it can be effectively bonded to the adhesive film above, thereby preventing the welding ribbon fastener 10 from slipping with the adhesive film during the lamination process, and thus ensuring the reliability of the connection between the welding ribbon 20 and the battery cell 30.

[0040] In addition, such as Figure 1 and 5 As shown, the welding strip fastener 10 also includes vent holes 104 spaced at intervals along the length X of the substrate 100. For example... Figure 2 and3 As shown, the vent 104 penetrates the weld band fixing member 10 in the thickness direction Z of the substrate 100. The shape of the vent 104 is, for example, one or a combination of circles, rectangles, triangles.

[0041] During the heating and vacuuming stage of lamination soldering, the lamination temperature is typically between 140°C and 160°C. During the alloying process of solder paste and solder ribbon on the battery surface, flux and other materials release gases, and the bonding and melting of substrates and adhesive films, such as adhesive tape, generates numerous bubbles. By providing vent holes 104 on the solder ribbon holder 10, the gases or bubbles generated during lamination soldering can be effectively discharged, suppressing the formation of gas cavities beneath the solder ribbon, thereby further suppressing the release of molten solder material.

[0042] In addition, such as Figure 3 As shown, the vent 104 is located between the first adhesive layers 101 on both sides. Therefore, by placing the vent 104 between the first adhesive layers 101 on both sides, the gas generated between the first adhesive layers 101 on both sides during the alloying process of solder and solder strip can be effectively discharged.

[0043] Preferably, such as Figure 2 As shown, the vent hole 104 and the second adhesive layer 102 are arranged alternately along the length direction X of the substrate 100. By alternating the arrangement of the vent hole 104 and the second adhesive layer 102, the vent hole 104 can penetrate the solder ribbon fixing member 10 while the second adhesive layer 102 is provided on the first surface 106 of the solder ribbon fixing member 10. That is, the vent hole 104 can be used to vent the solder ribbon while the second adhesive layer 102 is used to bond the solder ribbon.

[0044] like Figure 2 and 4 As shown, a groove 105 is provided on the first surface 106 of the substrate 100 corresponding to the position of the second adhesive layer 102. The second adhesive layer 102 is embedded in the groove 105. By providing a groove on the first surface 106, the second adhesive layer 102 can be easily received and held.

[0045] In addition, such as Figure 2 As shown, the second adhesive layer 102 can be flush with the first surface 106 of the substrate 100. Thus, when the second adhesive layer 102 is used to bond the solder ribbon, the solder ribbon can abut against the first surface 106 of the substrate, thereby enabling the lamination welding process to be performed effectively.

[0046] like Figure 8As shown, the thickness of the first adhesive layer 101 in the thickness direction Z is set to be greater than the thickness of the solder ribbon 20. Therefore, the effect of the first adhesive layer 101 in blocking the soldering material can be further ensured, more effectively preventing free solder generated during lamination soldering from penetrating into the battery area outside the first adhesive layer 101. Furthermore, the thickness of the first adhesive layer 101 in the thickness direction Z is greater than the thickness of the solder ribbon 20, allowing the first adhesive layer 101 to bond to the battery cell, and the second adhesive layer 102 to the solder, thereby achieving the effect of fixing the solder ribbon to the battery cell.

[0047] This utility model embodiment provides a photovoltaic cell string. For example... Figures 6 to 8 As shown, the photovoltaic cell string 1 includes: a plurality of cells 30, a solder ribbon 20 electrically connecting two adjacent cells 30, and a solder ribbon fixing member 10 as described in the above embodiment. The back surface of the cell 30 has positive grid lines 301 and negative grid lines 302, which extend along the width direction Y of the substrate 100 and are spaced apart along the length direction X of the substrate 100. Soldering material 304 and insulating material 303 are printed at intervals on the positive grid lines 301 and negative grid lines 302, wherein the soldering material 304 on the positive grid line 301 is aligned with the insulating material 303 on the negative grid line 302, and the insulating material 303 on the positive grid line 301 is aligned with the soldering material 304 on the negative grid line 302. The solder ribbon 20 extends along the length direction X of the substrate 100 and covers the welding material 304 on the positive grid line 301 and the insulating material 303 on the negative grid line 302 of the cell 30, or covers the insulating material 303 on the positive grid line 301 and the welding material 304 on the negative grid line 302 of the cell 30. The solder ribbon retainer 10 covers the solder ribbon 20 to fix the solder ribbon 20 to the cell 30 before soldering it to the cell 30.

[0048] The photovoltaic cell string 1 provided in this embodiment of the invention uses a first adhesive layer 101 on both sides of the substrate 100 in the width direction Y to arrange the solder ribbon 20 between the first adhesive layers 101. This acts as a barrier against the soldering material, effectively preventing free solder generated during lamination welding from seeping into the cell area outside the first adhesive layer 101, thereby preventing short circuits in the cell module. Furthermore, by providing a second adhesive layer 102 bonded to the solder ribbon 20, the solder ribbon 20 can be effectively fixed, preventing displacement of the solder ribbon 20 and ensuring a stable fixation and reliable electrical connection between the solder ribbon 20 and the cell 30.

[0049] In addition, such as Figure 8 As shown, the first adhesive layer 101 is located on both sides of the insulating material 303 and the soldering material 304 in the width direction Y. The insulating material 303 is, for example, an insulating adhesive. The soldering material 304 is, for example, solder paste. Preferably, as shown... Figure 3 and8 As shown, the coverage width L of the first adhesive layer 101 in the width direction Y is equal to the width of the insulating material 303 in the width direction Y.

[0050] By placing the first adhesive layer 101 on both sides of the insulating material 303 and the welding material 304, it is possible to more effectively prevent free tin generated by lamination welding from penetrating into the battery area outside the insulating material, thereby preventing short circuits in the battery assembly.

[0051] like Figure 8 As shown, the thickness of the first adhesive layer 101 is the same as the sum of the thickness of the welding material 304 and the thickness of the solder strip 20. By making the thickness of the first adhesive layer 101 the same as the sum of the thickness of the welding material 304 and the thickness of the solder strip 20, the height difference between the solder strip 20 and the battery surface is suppressed, thereby achieving a more reliable connection between the solder strip 20 and the battery surface, as well as a more reliable connection between the second adhesive layer 102 and the solder strip surface.

[0052] In addition, such as Figure 7 As shown, the vent 104 corresponds to the welding material 304 in the thickness direction Z. Since the vent 104 of the welding strip fastener 10 corresponds to the welding material 304 in the thickness direction Z, the gas generated when the welding strip 20 is welded to the battery cell 30 via the welding material 304 can be discharged from the corresponding upper vent 104, thereby more effectively suppressing the formation of gas cavities under the welding strip.

[0053] The examples provided above are merely illustrative to aid in understanding the structure, method, and core concept of this utility model. Those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this utility model.

Claims

1. A welding strip fixing member for fixing the welding strip (20) to the battery cell (30) before welding the welding strip (20) to the battery cell (30), characterized in that, The welding strip fastener (10) includes: a substrate (100) and a plurality of first adhesive layers (101) and a plurality of second adhesive layers (102) disposed on a first surface (106) of the substrate (100) facing the battery cell (30). The first adhesive layer (101) is spaced apart on both sides of the substrate (100) in the width direction (Y), and the second adhesive layer (102) is located between the first adhesive layers (101) on both sides and spaced apart along the length direction (X) of the substrate (100). The first adhesive layer (101) is bonded to the battery cell (30), the second adhesive layer (102) is bonded to the solder ribbon (20), and the solder ribbon (20) is located between the first adhesive layers (101) on both sides.

2. The solder strip holder of claim 1, wherein A third adhesive layer (103) is provided on the second surface (107) of the substrate (100) opposite to the first surface (106).

3. The solder strip holder according to claim 1 or 2, characterized in that Also includes: Vent holes (104) are arranged at intervals along the length (X) direction of the substrate (100). The vent (104) penetrates the welding strip fastener (10) in the thickness direction (Z) of the substrate (100).

4. The solder strip holder of claim 3, wherein The vent (104) is located between the first adhesive layers (101) on both sides.

5. The solder strip holder of claim 4, wherein The vent (104) and the second adhesive layer (102) are arranged alternately along the length direction (X) of the substrate (100).

6. The solder strip holder of claim 1, wherein The first surface (106) of the substrate (100) is provided with a groove (105) corresponding to the position of the second adhesive layer (102), and the second adhesive layer (102) is embedded in the groove (105).

7. The solder strip holder of claim 6, wherein The second adhesive layer (102) is flush with the first surface (106) of the substrate (100).

8. The solder strip holder of claim 1, wherein The thickness of the first adhesive layer (101) is greater than the thickness of the solder strip (20).

9. A string of photovoltaic cells, characterized in that, include: Multiple solar cells (30), solder strips (20) electrically connecting two adjacent solar cells (30), and solder strip fasteners (10) according to any one of claims 1-8. The back surface of the battery cell (30) has positive electrode grid lines (301) and negative electrode grid lines (302), the positive electrode grid lines (301) and the negative electrode grid lines (302) extend along the width direction (Y) of the substrate (100) and are spaced apart along the length direction (X) of the substrate (100). Soldering material (304) and insulating material (303) are printed alternately on the positive gate line (301) and the negative gate line (302), wherein the soldering material (304) on the positive gate line (301) is aligned with the insulating material (303) on the negative gate line (302), and the insulating material (303) on the positive gate line (301) is aligned with the soldering material (304) on the negative gate line (302). The solder strip (20) extends along the length direction (X) of the substrate (100) and covers the solder material (304) on the positive grid line (301) and the insulating material (303) on the negative grid line (302) of the battery cell (30), or covers the insulating material (303) on the positive grid line (301) and the solder material (304) on the negative grid line (302) of the battery cell (30). The welding ribbon fastener (10) covers the welding ribbon (20) to secure the welding ribbon (20) to the battery cell (30) before welding the welding ribbon (20) to the battery cell (30).

10. The photovoltaic cell string according to claim 9, characterized in that, The first adhesive layer (101) is located on both sides of the insulating material (303) and the welding material (304) in the width direction (Y). The thickness of the first adhesive layer (101) is the same as the sum of the thickness of the welding material (304) and the thickness of the solder strip (20). The vent (104) corresponds to the welding material (304) in the thickness direction (Z).

Images