Solar cell string, preparation method thereof and welding equipment
By employing a method of first briefly accumulating heat and then rapidly cooling it during the fabrication process of solar cell strings, the problem of poor welding in traditional methods has been solved, resulting in more efficient welding and a lower probability of incomplete welds.
Patent Information
- Application Number
- CN202411612573.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-11-25
AI Technical Summary
Traditional methods for fabricating solar cell strings are prone to poor welding, especially incomplete soldering.
The process involves first performing a first heat treatment (140℃~200℃, 2s~4s), then a second heat treatment (keeping the temperature greater than or equal to the melting point of the solder strip, 4s~10s), and finally a rapid cooling treatment (1s~3s) to cure the thermosetting adhesive and solder strip, thus forming an electrical contact.
This reduces the probability of cold solder joints, minimizes the occurrence of poor soldering, and reduces damage to solar cells, thus maintaining production efficiency.
Smart Images
Figure CN121013448A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic technology, and in particular to a solar cell string and its preparation method and welding equipment. Background Technology
[0002] In the fabrication of photovoltaic (PV) modules, multiple solar cells are typically connected in series or parallel using solder ribbons to form a solar cell string. The solar cell string is then encapsulated to create the PV module. For gridless solar cells, the solder ribbons are usually fixed with adhesive before welding. Traditional methods for fabricating solar cell strings are prone to welding defects. Summary of the Invention
[0003] Therefore, it is necessary to provide a solar cell string, its fabrication method, and welding equipment. The solar cell string fabrication method of this application can reduce the probability of forming cold solder joints in the solar cell string and reduce the occurrence of welding defects.
[0004] In a first aspect, this application provides a method for fabricating a solar cell string, comprising the following steps:
[0005] A thermosetting adhesive and solder ribbon are applied to the surface of a solar cell to obtain an intermediate product.
[0006] The intermediate product is subjected to a first heat treatment, a second heat treatment, and a cooling treatment in sequence to cure the thermosetting adhesive and to form an electrical contact between the solder ribbon and the solar cell.
[0007] The temperature of the first heat treatment is 140℃~200℃, and the time of the first heat treatment is 2s~4s;
[0008] During the second heat treatment, the temperature of the intermediate product is maintained at or above the melting point of the solder strip, and the time of the second heat treatment is 4s to 10s.
[0009] The welding strip is cured by the cooling treatment, and the cooling treatment time is 1s to 3s.
[0010] In some embodiments, the curing temperature of the thermosetting adhesive is below 120°C.
[0011] In some embodiments, the melting temperature of the solder strip is below 185°C.
[0012] In some embodiments, subjecting the intermediate product to a sequential first heat treatment, a second heat treatment, and a cooling treatment includes the following steps:
[0013] The intermediate product is subjected to a first heat treatment, a second heat treatment, and a cooling treatment sequentially using welding equipment. The welding equipment includes sequentially arranged adjacent first heat treatment zones, second heat treatment zones, and cooling treatment zones. The first heat treatment zone is used to perform the first heat treatment on the intermediate product, the second heat treatment zone is used to perform the second heat treatment on the intermediate product, and the cooling treatment zone is used to perform the cooling treatment on the intermediate product. The welding equipment also includes a conveying device for conveying the intermediate product sequentially through the first heat treatment zone, the second heat treatment zone, and the cooling treatment zone.
[0014] In some embodiments, the welding equipment further includes a first heat treatment device located within a first heat treatment area. The first heat treatment device includes a first heating element and a second heating element arranged at a relative interval, with the first heating element and the second heating element respectively disposed on opposite sides of the conveying device.
[0015] In some embodiments, the welding equipment further includes a second heat treatment device located within the second heat treatment area. The second heat treatment device includes a third heating element and a fourth heating element arranged at a relative interval, which are respectively disposed on opposite sides of the conveying device.
[0016] In some embodiments, the welding equipment further includes a cooling device comprising a first cooling element and a second cooling element arranged at a relative interval, the first cooling element and the second cooling element being respectively disposed on two opposite sides of the conveying device.
[0017] Secondly, this application provides a solar cell string, which is prepared by any of the solar cell string preparation methods described above.
[0018] Thirdly, this application provides a welding apparatus for preparing solar cell strings using any of the above-described methods, comprising: sequentially arranged adjacent first heat treatment regions, second heat treatment regions, and cooling treatment regions, wherein the first heat treatment regions are used to perform the first heat treatment on the intermediate product, the second heat treatment regions are used to perform the second heat treatment on the intermediate product, and the cooling treatment regions are used to perform the cooling treatment on the intermediate product; the welding apparatus further comprises a conveying device for conveying the intermediate product sequentially through the first heat treatment region, the second heat treatment region, and the cooling treatment region.
[0019] In some embodiments, the welding equipment further includes a first heat treatment device located within a first heat treatment area. The first heat treatment device includes a first heating element and a second heating element arranged at a relative interval, with the first heating element and the second heating element respectively disposed on opposite sides of the conveying device.
[0020] In some embodiments, the welding equipment further includes a second heat treatment device located within the second heat treatment area. The second heat treatment device includes a third heating element and a fourth heating element arranged at a relative interval, which are respectively disposed on opposite sides of the conveying device.
[0021] In some embodiments, the welding equipment further includes a cooling device comprising a first cooling element and a second cooling element arranged at a relative interval, the first cooling element and the second cooling element being respectively disposed on two opposite sides of the conveying device.
[0022] In the aforementioned method for preparing solar cell strings, the intermediate product undergoes a first heat treatment at a temperature of 140℃~200℃ for 2s~4s. The main purpose of this first heat treatment is to briefly accumulate temperature in the solar cells, facilitating the subsequent connection of the solder ribbon to the solar cells and reducing the curing time of the thermosetting adhesive. The intermediate product then undergoes a second heat treatment, during which the temperature is maintained above or equal to the melting point of the solder ribbon, for 4s~10s. The main purpose of this second heat treatment is to establish an electrical connection between the solder ribbon and the solar cells. Due to the accumulated temperature from the first heat treatment, the second heat treatment can be performed in a shorter time to melt the solder ribbon, making it easier to control the welding effect. Furthermore, compared to traditional methods of preparing solar cell strings by directly performing high-temperature welding at temperatures above 180℃, the method described in this application, through the combination of the first and second heat treatments, can simultaneously achieve the curing of the thermosetting adhesive and the welding of the solder ribbon, resulting in a gentler welding process with less damage to the solar cells. Furthermore, in the cooling process, compared to the relatively slow cooling method of directly cooling the solar cells in the air in traditional solar cell string fabrication methods, the solar cell string fabrication method of this application solidifies the solder ribbon through a cooling process within a short time of 1s to 3s. This rapid cooling reduces the impact of accumulated heat on the solar cells and prevents the solder ribbon from shifting due to prolonged molten state, thus preventing the formation of cold solder joints. The solar cell string fabrication method of this application can reduce the probability of cold solder joints in solar cell strings without reducing production efficiency, thereby reducing the occurrence of welding defects. Attached Figure Description
[0023] Figure 1This is a schematic diagram of the structure of a welding device provided in an embodiment of this application.
[0024] Explanation of reference numerals in the attached figures
[0025] 10. First heat treatment zone; 11. First heating element; 12. Second heating element; 20. Second heat treatment zone; 21. Third heating element; 22. Fourth heating element; 30. Cooling treatment zone; 31. First cooling element; 32. Second cooling element; 40. Solar cell; 50. Conveying device. Detailed Implementation
[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0028] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0030] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0031] One embodiment of this application provides a method for fabricating a solar cell string, comprising the following steps:
[0032] A thermosetting adhesive and solder ribbon are applied to the surface of a solar cell to obtain an intermediate product.
[0033] The intermediate product is subjected to a series of heat treatments, including a first heat treatment, a second heat treatment, and a cooling treatment, to cure the thermosetting adhesive and to form an electrical contact between the solder ribbon and the solar cell.
[0034] The temperature of the first heat treatment is 140℃~200℃, and the time of the first heat treatment is 2s~4s;
[0035] During the second heat treatment, the temperature of the intermediate product is kept greater than or equal to the melting point of the solder strip, and the second heat treatment time is 4s to 10s.
[0036] The intermediate product is cooled to below 100°C by a cooling process, which takes 1 to 3 seconds.
[0037] In the aforementioned method for preparing solar cell strings, the intermediate product undergoes a first heat treatment at a temperature of 140℃~200℃ for 2s~4s. The main purpose of this first heat treatment is to briefly accumulate temperature in the solar cells, facilitating the subsequent connection of the solder ribbon to the solar cells and reducing the curing time of the thermosetting adhesive. The intermediate product then undergoes a second heat treatment, during which the temperature is maintained above or equal to the melting point of the solder ribbon, for 4s~10s. The main purpose of this second heat treatment is to establish an electrical connection between the solder ribbon and the solar cells. Due to the accumulated temperature from the first heat treatment, the second heat treatment can be performed in a shorter time to melt the solder ribbon, making it easier to control the welding effect. Furthermore, compared to traditional methods of preparing solar cell strings by directly performing high-temperature welding at temperatures above 180℃, the method described in this application, through the combination of the first and second heat treatments, can simultaneously achieve the curing of the thermosetting adhesive and the welding of the solder ribbon, resulting in a gentler welding process with less damage to the solar cells. Furthermore, in the cooling process, compared to the relatively slow cooling method of directly cooling the solar cells in the air in traditional solar cell string fabrication methods, the solar cell string fabrication method of this application solidifies the solder ribbon through a cooling process within a short time of 1s to 3s. This rapid cooling reduces the impact of accumulated heat on the solar cells and prevents the solder ribbon from shifting due to prolonged molten state, thus preventing the formation of cold solder joints. The solar cell string fabrication method of this application can reduce the probability of cold solder joints in solar cell strings without reducing production efficiency, thereby reducing the occurrence of welding defects.
[0038] It is understandable that thermosetting adhesives refer to adhesives that can be cured by heating. The temperature of the first heat treatment refers to the set temperature during the first heat treatment process.
[0039] Optionally, the temperature of the first heat treatment is 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃ or 200℃, or the temperature of the first heat treatment may be within the range of any two of the above temperatures.
[0040] Optionally, the time for the first heat treatment is 2s, 2.2s, 2.4s, 2.6s, 2.8s, 3s, 3.2s, 3.4s, 3.6s, 3.8s, or 4s, or the time for the first heat treatment can be within any two of the above times.
[0041] Optionally, during the second heat treatment, the temperature of the intermediate product is maintained at 150℃~190℃. Further optionally, during the second heat treatment, the temperature of the intermediate product is maintained at 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, or 190℃; alternatively, during the second heat treatment, the temperature of the intermediate product may be maintained within any two of the aforementioned temperatures.
[0042] Optionally, the second heat treatment time is 4s, 5s, 6s, 7s, 8s, 9s, or 10s, or the second heat treatment time can be within any two of the above temperatures.
[0043] Optionally, the cooling process cools the intermediate product to below 100°C, or the cooling process cools the solar cell to below 90°C, or the cooling process cools the solar cell to below 80°C, or the cooling process cools the solar cell to below 70°C, or the cooling process cools the solar cell to below 60°C.
[0044] Optionally, the cooling time can be 1s, 1.2s, 1.4s, 1.6s, 1.8s, 2s, 2.2s, 2.4s, 2.6s, 2.8s, or 3s, or the cooling time can be within any two of the above temperatures.
[0045] In some embodiments, the curing temperature of the thermosetting adhesive is below 120°C.
[0046] Optionally, the curing temperature of the thermosetting adhesive is 60℃~120℃. Further optionally, the curing temperature of the thermosetting adhesive is 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, or 120℃, or the curing temperature of the thermosetting adhesive may be within any two of the above temperatures.
[0047] In some embodiments, the melting temperature of the solder strip is below 185°C.
[0048] Optionally, the melting temperature of the solder strip is 130℃~185℃. Further optionally, the melting temperature of the solder strip is 130℃, 140℃, 150℃, 160℃, 165℃, 170℃, 175℃, 180℃ or 185℃, or the melting temperature of the solder strip can be within the range of any two of the above temperatures.
[0049] In some embodiments, sequentially subjecting the intermediate product to a first heat treatment, a second heat treatment, and a cooling treatment includes the following steps:
[0050] The intermediate product is subjected to a first heat treatment, a second heat treatment, and a cooling treatment sequentially using welding equipment. The welding equipment includes adjacent first heat treatment zones, second heat treatment zones, and cooling treatment zones arranged in sequence. The first heat treatment zone is used to perform the first heat treatment on the intermediate product, the second heat treatment zone is used to perform the second heat treatment on the intermediate product, and the cooling treatment zone is used to perform the cooling treatment on the intermediate product. The welding equipment also includes a conveying device for conveying the intermediate product sequentially through the first heat treatment zone, the second heat treatment zone, and the cooling treatment zone.
[0051] By using a conveying device to sequentially pass intermediate products through a first heat treatment area, a second heat treatment area, and a cooling treatment area along its conveying direction, the first heat treatment, the second heat treatment, and the cooling treatment can be carried out automatically and continuously. This allows for the continuous welding of multiple solar cells to prepare solar cell strings, thereby achieving high production efficiency.
[0052] In some embodiments, the welding equipment further includes a first heat treatment device located within a first heat treatment area. The first heat treatment device includes a first heating element and a second heating element arranged at a relative interval, which are respectively disposed on opposite sides of the conveying device.
[0053] The solar cell is subjected to a first heat treatment by a first heating element and a second heating element respectively disposed on two opposite sides of the conveying device, and the temperature control effect during the first heat treatment of the solar cell is good.
[0054] In some embodiments, the first heating element and / or the second heating element includes an infrared heating element.
[0055] In some embodiments, the first heating element and the second heating element are used to heat the front and back sides of the solar cell, respectively.
[0056] In some embodiments, the welding equipment further includes a second heat treatment device located within a second heat treatment area. The second heat treatment device includes a third heating element and a fourth heating element arranged at a relative interval, which are respectively disposed on opposite sides of the conveying device.
[0057] The solar cells are subjected to a second heat treatment by the third and fourth heating elements respectively located on two opposite sides of the conveying device, resulting in better temperature control during the second heat treatment of the solar cells.
[0058] In some embodiments, the third and / or fourth heating element includes an infrared heating element.
[0059] In some embodiments, the third and fourth heating elements are used to heat the front and back sides of the solar cell, respectively.
[0060] In some embodiments, the welding equipment further includes a cooling device, which includes a first cooling element and a second cooling element arranged at a relative interval, the first cooling element and the second cooling element being respectively disposed on two opposite sides of the conveying device.
[0061] By having the first and second cooling components respectively located on opposite sides of the conveying device, the cooling effect on the solar cells is better.
[0062] In some embodiments, the first cooling element and the second cooling element are each independently selected from at least one of air-cooled cooling elements and water-cooled cooling elements.
[0063] In some embodiments, the first cooling element and the second cooling element are used to cool the front and back sides of the solar cell, respectively.
[0064] Another embodiment of this application provides a solar cell string, which is prepared by any of the above-described methods for preparing a solar cell string.
[0065] In some embodiments, the solar cell string includes multiple solar cells connected by solder ribbons; each solar cell has a thermosetting adhesive on its surface to secure the solder ribbons to the surface of the solar cell.
[0066] Reference Figure 1 As shown, another embodiment of this application provides a welding apparatus for preparing solar cell strings using any of the above-mentioned methods, comprising: sequentially arranged adjacent first heat treatment regions 10, second heat treatment regions 20, and cooling treatment regions 30, wherein the first heat treatment regions 10 are used to perform a first heat treatment on the intermediate product, the second heat treatment regions 20 are used to perform a second heat treatment on the intermediate product, and the cooling treatment regions 30 are used to perform a cooling treatment on the intermediate product; the welding apparatus further comprises a conveying device 50, which is used to convey the intermediate product sequentially through the first heat treatment regions 10, the second heat treatment regions 20, and the cooling treatment regions 30.
[0067] In some embodiments, the welding equipment further includes a first heat treatment device located within a first heat treatment zone 10. The first heat treatment device includes a first heating element 11 and a second heating element 12 arranged at relative intervals, with the first heating element 11 and the second heating element 12 respectively disposed on two opposite sides of the conveying device 50.
[0068] In some embodiments, the welding equipment further includes a second heat treatment device located within a second heat treatment area. The second heat treatment device includes a third heating element 21 and a fourth heating element 22 arranged at opposite intervals, which are respectively disposed on two opposite sides of the conveying device 50.
[0069] In some embodiments, the welding equipment further includes a cooling device, which includes a first cooling element 31 and a second cooling element 32 arranged at relative intervals, and the first cooling element 31 and the second cooling element 32 are respectively arranged on two opposite sides of the conveying device 50.
[0070] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0071] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.
Claims
1. A method for fabricating a solar cell string, characterized in that, Includes the following steps: A thermosetting adhesive and solder ribbon are applied to the surface of a solar cell to obtain an intermediate product. The intermediate product is subjected to a first heat treatment, a second heat treatment, and a cooling treatment in sequence to cure the thermosetting adhesive and to form an electrical contact between the solder ribbon and the solar cell. The temperature of the first heat treatment is 140℃~200℃, and the time of the first heat treatment is 2s~4s; During the second heat treatment, the temperature of the intermediate product is maintained at or above the melting point of the solder strip, and the time of the second heat treatment is 4s to 10s. The welding strip is cured by the cooling treatment, and the cooling treatment time is 1s to 3s.
2. The method for preparing a solar cell string according to claim 1, characterized in that, The curing temperature of the thermosetting adhesive is below 120°C.
3. The method for preparing a solar cell string according to claim 1, characterized in that, The melting temperature of the welding strip is below 185°C.
4. The method for preparing a solar cell string according to claim 1, characterized in that, The intermediate product undergoes a series of sequential heat treatments, including a first heat treatment, a second heat treatment, and a cooling treatment, comprising the following steps: The intermediate product is subjected to a first heat treatment, a second heat treatment, and a cooling treatment sequentially using welding equipment. The welding equipment includes sequentially arranged adjacent first heat treatment zones, second heat treatment zones, and cooling treatment zones. The first heat treatment zone is used to perform the first heat treatment on the intermediate product, the second heat treatment zone is used to perform the second heat treatment on the intermediate product, and the cooling treatment zone is used to perform the cooling treatment on the intermediate product. The welding equipment also includes a conveying device for conveying the intermediate product sequentially through the first heat treatment zone, the second heat treatment zone, and the cooling treatment zone.
5. The method for preparing a solar cell string according to claim 4, characterized in that, The welding equipment further includes a first heat treatment device located within the first heat treatment area. The first heat treatment device includes a first heating element and a second heating element arranged at a relative interval, with the first heating element and the second heating element respectively disposed on opposite sides of the conveying device.
6. The method for preparing a solar cell string according to claim 4, characterized in that, The welding equipment further includes a second heat treatment device located within the second heat treatment area. The second heat treatment device includes a third heating element and a fourth heating element arranged at relative intervals, which are respectively disposed on opposite sides of the conveying device.
7. The method for preparing a solar cell string according to claim 4, characterized in that, The welding equipment also includes a cooling device, which includes a first cooling element and a second cooling element arranged at a relative interval, and the first cooling element and the second cooling element are respectively arranged on two opposite sides of the conveying device.
8. A solar cell string, characterized in that, The solar cell string is prepared by the method described in any one of claims 1 to 7.
9. A welding apparatus for preparing solar cell strings using the method for preparing solar cell strings according to any one of claims 1 to 7, characterized in that, include: The welding equipment comprises a first heat treatment zone, a second heat treatment zone, and a cooling treatment zone arranged in sequence. The first heat treatment zone is used to perform the first heat treatment on the intermediate product, the second heat treatment zone is used to perform the second heat treatment on the intermediate product, and the cooling treatment zone is used to perform the cooling treatment on the intermediate product. The welding equipment also includes a conveying device for conveying the intermediate product sequentially through the first heat treatment zone, the second heat treatment zone, and the cooling treatment zone.
10. The welding equipment according to claim 9, characterized in that, The welding equipment further includes a first heat treatment device located within a first heat treatment area. The first heat treatment device includes a first heating element and a second heating element arranged at a relative interval, respectively disposed on opposite sides of the conveying device; and / or The welding equipment further includes a second heat treatment device located within a second heat treatment area. The second heat treatment device includes a third heating element and a fourth heating element arranged at a relative interval, respectively disposed on opposite sides of the conveying device; and / or The welding equipment also includes a cooling device, which includes a first cooling element and a second cooling element arranged at a relative interval, and the first cooling element and the second cooling element are respectively arranged on two opposite sides of the conveying device.