A black busbar for photovoltaic modules, its preparation method, and the photovoltaic module.

Abstract

This invention discloses a black busbar for photovoltaic modules, its preparation method, and a photovoltaic module, belonging to the field of photovoltaic module technology, to solve the problem of rapid output power degradation in photovoltaic modules using existing black busbars. The black busbar for photovoltaic modules of this invention comprises, in sequence: a tin layer, a copper base layer, a first metal layer, and a black resin layer, wherein the melting point of the first metal layer is higher than that of the tin layer. The photovoltaic module of this invention includes the above-described black busbar for photovoltaic modules. The output power degradation of photovoltaic modules using the black busbar of this invention is reduced.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic module technology, specifically relating to a black busbar for photovoltaic modules, its preparation method, and a photovoltaic module. Background Technology

[0002] Currently, photovoltaic (PV) modules are widely used in distributed PV systems such as rooftops and building facades. For these types of distributed PV systems, the PV modules must be black. Therefore, black busbars are required.

[0003] The prior art provides a black busbar, which includes a copper base layer, a tin layer disposed on one surface of the copper base layer, and a black resin coating disposed on another surface of the copper base layer.

[0004] However, after long-term use, the inventors discovered that photovoltaic modules using existing black busbars suffer from rapid output power degradation. Therefore, there is an urgent need to provide a black busbar that has a good appearance, good stability, and low cost. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a black busbar for photovoltaic modules, a method for preparing the same, and a photovoltaic module, which can solve the following technical problem: the output power of photovoltaic modules using existing black busbars decays rapidly.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] On one hand, the present invention provides a black busbar for photovoltaic modules, comprising, in sequence: a tin layer, a copper base layer, a first metal layer and a black resin layer, wherein the melting point of the first metal layer is higher than that of the tin layer.

[0008] Furthermore, the melting point of the first metal layer is higher than 400°C.

[0009] Furthermore, the first metal layer is aluminum, an aluminum alloy, nickel, or a nickel alloy.

[0010] Furthermore, the thickness of the first metal layer is 40 to 800 μm.

[0011] Furthermore, the thickness of the tin layer is 15–25 μm.

[0012] Furthermore, the thickness of the black resin layer is 5–20 μm.

[0013] Furthermore, a second metal layer is disposed between the tin layer and the copper base layer.

[0014] Furthermore, the second metal layer is made of the same material as the first metal layer.

[0015] Furthermore, the surface of the black resin layer has an uneven structure.

[0016] Furthermore, the surface dyne value of the black resin layer is 40 or higher.

[0017] On one hand, the present invention provides a method for preparing a black busbar for photovoltaic modules, comprising:

[0018] S1. Prepare the copper substrate;

[0019] S2. A first metal layer is provided on one side surface of the copper base layer;

[0020] S3. A black resin layer is formed on the surface of the first metal layer;

[0021] S4. A tin layer is plated on the other side of the copper base layer using a back-to-back method.

[0022] S5. Perform corona treatment on the black resin layer to obtain a black busbar;

[0023] The melting point of the first metal layer is higher than that of the tin layer.

[0024] On the other hand, the present invention provides a method for preparing a black busbar for photovoltaic modules, comprising:

[0025] Step 1: Prepare the copper substrate;

[0026] Step 2: Deposit a first metal layer and a second metal layer on both sides of the copper base layer, respectively;

[0027] Step 3: Deposit a black resin layer on the surface of the first metal layer;

[0028] Step 4: Apply a tin layer to the surface of the second metal layer using a back-to-back method;

[0029] Step 5: Perform corona treatment on the black resin layer to obtain a black busbar;

[0030] The melting point of the first metal layer is higher than that of the tin layer.

[0031] On the other hand, the present invention provides a photovoltaic module including the aforementioned black busbar for photovoltaic modules.

[0032] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0033] a) The black busbar for photovoltaic modules provided by the present invention has a first metal layer between the copper substrate and the black resin layer. During use, the first metal layer can block moisture and oxygen, thereby protecting the copper substrate, preventing the copper substrate from being oxidized, and thus slowing down the decay of the module's output power.

[0034] b) The first metal layer has a high melting point. During welding, the first metal layer will not melt, which will not affect the adhesion between the black resin layer and the adhesive film, thus avoiding delamination during welding.

[0035] c) In the preparation process of the black busbar for photovoltaic modules provided by this invention, a high-melting-point metal layer and a black resin layer are first plated, followed by a tin layer. This prevents the tin layer from melting and failing to form when the high-melting-point metal layer is plated first. Finally, the corona treatment of the black resin layer significantly improves the adhesion between the black resin layer and the photovoltaic module encapsulation film.

[0036] d) The method for preparing the black busbar provided by the present invention is simple, and the cost of the black resin layer and the first metal layer used is also low. Therefore, the cost of the black busbar provided by the embodiments of the present invention is not significantly increased, the cost is low, and the black busbar of the present invention has a better appearance.

[0037] e) The black busbar of the photovoltaic module of the present invention prevents the copper base layer from being corroded by setting a high-melting-point first metal layer between the black resin layer and the copper base layer, thereby reducing the output power attenuation of the photovoltaic module.

[0038] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained from the written description. Attached Figure Description

[0039] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0040] Figure 1 This is a schematic diagram of the overall structure of the black busbar in Embodiment 1 of the present invention;

[0041] Figure 2 This is a schematic diagram of the overall structure of the black busbar in Embodiment 2 of the present invention;

[0042] Figure 3 This is a schematic diagram of clamping two busbars together using a back-to-back method in Embodiment 1 of the present invention;

[0043] Figure 4 This is a front view image of a photovoltaic module including the busbars of Comparative Example 1;

[0044] Figure 5 This is a front view image of a photovoltaic module including the busbar of Example 1.

[0045] Figure Labels

[0046] 1-Tin layer, 2-Copper base layer, 3-First metal layer, 4-Black resin layer, 5-Second metal layer. Detailed Implementation

[0047] The following embodiments provide a detailed description of the present invention. These embodiments are exemplary and intended to describe implementation methods of the present invention, and do not limit the scope of the invention.

[0048] During the photovoltaic (PV) module assembly process, the PV module laminates are placed into a laminator for lamination. These laminates include PV glass, encapsulant film, cell array, and PV backsheet. The cell array includes busbars. The busbars in the cell array need to be soldered to the solder strips first.

[0049] Existing technology provides a black busbar comprising a copper substrate, a tin layer disposed on one surface of the copper substrate, and a black resin coating disposed on the other surface of the copper substrate. However, after long-term use, the inventors found that photovoltaic modules using the existing black busbar experience rapid power degradation. Further research revealed that during use, moisture and oxygen can enter the photovoltaic module. Because the black resin coating provides relatively weak protection against moisture and oxygen, these substances can penetrate and corrode the copper substrate. Corrosion of the copper substrate increases its resistance, accelerating the power degradation of the module (normal photovoltaic modules experience some power degradation after leaving the factory, but corrosion of the copper substrate accelerates this degradation). Severe corrosion of the copper substrate can even cause the module to burn out. Therefore, there is an urgent need to provide a black busbar that offers good appearance, high stability, and low cost.

[0050] Based on the above findings and research analysis, the present invention provides a black busbar for photovoltaic modules, comprising, in sequence: a tin layer 1, a copper base layer 2, a first metal layer 3, and a black resin layer 4; the melting point of the first metal layer 3 is higher than that of the tin layer 1.

[0051] It should be noted that, considering that the black busbars used in photovoltaic modules need to be welded to the encapsulant film during use, and the busbar conducts heat quickly during welding, if the melting point of the metal layer is low, the metal layer is prone to melting and flowing during welding, which will make the adhesion between the black resin layer and the encapsulant film weak and aggravate the delamination phenomenon; therefore, the melting point of the first metal layer 3 is controlled to be higher than 400°C, for example, it can be above 450°C, above 500°C, above 550°C, above 600°C, or above 650°C, etc.

[0052] Specifically, the first metal layer 3 can be aluminum, aluminum alloy, nickel, or nickel alloy; considering manufacturing costs, the first metal layer 3 can be a low-cost metal, preferably aluminum.

[0053] Compared with the prior art, the black busbar for photovoltaic modules provided by the present invention has a first metal layer between the copper base layer and the black resin layer. During use, the first metal layer can block moisture and oxygen, thereby protecting the copper base layer, preventing the copper base layer from being oxidized, and thus slowing down the decay of the module's output power. In addition, the first metal layer has a high melting point, so it will not melt during welding, thus avoiding delamination during welding.

[0054] To facilitate the fabrication of the black busbar, a second metal layer 5 can also be provided between the tin layer 1 and the copper base layer 2. The second metal layer 5 is made of the same material as the first metal layer 3.

[0055] Specifically, considering that excessive thickness of the first metal layer 3 would result in high cost and manufacturing difficulty for the black busbar, while insufficient thickness would lead to high resistivity of the black busbar, affecting the component's output power, the thickness of the first metal layer 3 is controlled to be 40–800 μm (1 μm = 0.0254 μm, the same below), for example, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 420 μm, 440 μm, 450 μm, 460 μm, and 480 μm. The thickness of the first metal layer can be selected by considering factors such as cost and resistivity. For example, for low-cost metals such as aluminum, a thickness of 400µm or more can be selected, while for higher-cost metals, a thickness of 40-300µm can be selected.

[0056] The thickness of the second metal layer 5 can be the same as the thickness of the first metal layer 3.

[0057] Specifically, the copper base layer 2 mentioned above is oxygen-free copper, and its copper content is required to be ≥99.9%.

[0058] Specifically, if the thickness of tin layer 1 is too large, the cost of the black busbar will be high and the manufacturing process will be difficult; if it is too small, the resistivity of the black busbar will be high, affecting the output power of the component. Therefore, the thickness of tin layer 1 is controlled to be 15-25μm, such as 16μm, 18μm, 20μm, 22μm, 24μm, etc.

[0059] Specifically, if the thickness of the black resin layer 4 is too large, the cost of the black busbar will be high and the manufacturing process will be difficult; if it is too small, the resistivity of the black busbar will be high, affecting the output power of the component. Therefore, the thickness of the black resin layer 4 is controlled to be 5 to 20 μm, such as 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 15 μm, 16 μm, 18 μm, etc.

[0060] In existing modules using black busbars, large areas of white air bubbles appear near the bends in the busbars on the front of the module, significantly affecting the module's appearance (e.g., Figure 4 (The circle indicates the location). The inventors discovered that the large areas of white bubble clusters were caused by poor adhesion between the black resin layer and the photovoltaic module encapsulation film, leading to delamination between the black resin layer and the encapsulation film. Therefore, improving the adhesion strength between the black resin layer and the encapsulation film can solve the problem of white bubble clusters.

[0061] Specifically, the bonding strength can be improved by increasing the contact area between the black resin layer 4 and the adhesive film. This contact area can be increased by creating an uneven surface on the black resin layer 4. In one possible implementation, after forming the first metal layer 3, an uneven surface can be formed on the surface of the first metal layer 3 by etching or other methods, and then the black resin layer 4 can be formed on the first metal layer 3, thereby creating an uneven surface on the black resin layer 4.

[0062] Optionally, the surface of the black resin layer 4 has inverted pyramid-shaped protrusions.

[0063] Specifically, the adhesion strength between the black resin layer 4 and the adhesive film can also be improved by increasing the dyne value of the surface of the black resin layer 4. For example, the dyne value of the surface of the black resin layer 4 can be increased by corona treatment.

[0064] The two methods can also be combined, that is, on the basis of making the surface of the black resin layer 4 have an uneven structure, the surface of the black resin layer 4 is subjected to corona treatment.

[0065] Specifically, the higher the dyne value of the black resin layer 4, the better the adhesion to the adhesive film. Conversely, if the dyne value is too low, it is easy to delaminate and generate bubbles. Therefore, the dyne value of the black resin layer 4 should be controlled to be above 40.

[0066] In this invention, the composition of the black resin layer 4 is not particularly required; commercially available black inks or coatings used in the photovoltaic field are acceptable. For example, a composite resin formed by mixing two or more of the main components of amino resin, acrylic resin, and epoxy resin in a certain proportion can be used.

[0067] This invention also provides a method for preparing a black busbar for photovoltaic modules, comprising:

[0068] S1. Prepare copper substrate 2;

[0069] S2. A first metal layer 3 is provided on one side surface of the copper base layer 2;

[0070] S3. Black composite resin 4 is disposed on the surface of the first metal layer 3;

[0071] S4. A tin layer 1 is plated on the other side of the copper base layer 2 using a back-to-back method;

[0072] S5. Corona treatment is performed on black composite resin 4 to obtain black busbars.

[0073] Specifically, in S4 above, the tin plating layer is applied using a chemical immersion plating method.

[0074] Specifically, such as Figure 3 As shown, in S4 above, the process of plating a tin layer 1 on the other side of the copper substrate 2 using a back-to-back method includes:

[0075] S401. Align the black composite resin 4 side of the two busbars plated with copper base layer 2, first metal layer 3 and black composite resin 4, and clamp the two aligned busbars with clamp 6.

[0076] S402. After clamping, the busbar is immersed in a chemical solution for tin plating.

[0077] Specifically, in S5 above, the two busbars clamped after the tin plating layer in S4 need to be separated, and then corona treatment is performed on the black composite resin 4.

[0078] It should be noted that if the black busbar also includes a second metal layer 5, then in S2, a first metal layer 3 and a second metal layer 5 are respectively plated on both sides of the copper base layer 2.

[0079] It should be noted that the surface of the black resin layer may also be provided with an uneven structure.

[0080] Compared with existing technologies, the method of this invention first deposits a high-melting-point metal layer and a black resin layer, and then deposits a tin layer. This prevents the tin layer from melting and failing to form when the high-melting-point metal layer is deposited first. The final corona treatment of the black resin layer significantly improves the adhesion between the black resin layer and the photovoltaic module encapsulation film, effectively preventing large areas of white bubbles from appearing near the bends of the busbars on the front of the module, thereby improving the module's appearance.

[0081] The present invention also provides a photovoltaic module, which includes the aforementioned black busbar for photovoltaic modules. The black busbar of the photovoltaic module of the present invention prevents corrosion of the copper substrate by setting a high-melting-point first metal layer between the black resin layer and the copper substrate, thereby reducing the output power attenuation of the photovoltaic module. Furthermore, due to the strong adhesion between the black resin layer and the encapsulating film, there are almost no white air bubbles near the bends of the busbar on the front of the module, thus improving the appearance of the module.

[0082] The following specific embodiments will demonstrate the black busbar for photovoltaic modules and its preparation method of the present invention.

[0083] Example 1

[0084] This embodiment provides a black busbar for photovoltaic modules, such as... Figure 1 As shown, from top to bottom, it comprises: a tin layer 1, a copper base layer 2, a first metal layer 3, and a black resin layer 4. The tin layer 1 has a thickness of 20 μm, the first metal layer 3 has a thickness of 40 μm, the copper base layer 2 contains 99.95% copper, and the black resin layer 4 has a thickness of 10 μm and a dyne value of 50. The first metal layer 3 is made of aluminum.

[0085] The preparation method of the above-mentioned black busbar for photovoltaic modules includes the following steps:

[0086] S1. Prepare copper substrate 2;

[0087] S2. A first metal layer 3 is disposed on one side of the copper base layer 2;

[0088] S3. A black resin layer 4 is disposed on the surface of the first metal layer 3;

[0089] S4. A tin layer 1 is plated on the surface of the copper base layer 2 using a back-to-back method;

[0090] S5. Corona treatment is performed on the black composite resin coating 4 to obtain a black busbar.

[0091] Example 2

[0092] This embodiment provides a black busbar for photovoltaic modules, which has the same structure as in embodiment 1, except that the thickness of the first metal layer 3 is 400µm.

[0093] Example 3

[0094] This embodiment provides a black busbar for photovoltaic modules, such as... Figure 2As shown, from top to bottom, it comprises: a tin layer 1, a second metal layer 5, a copper base layer 2, a first metal layer 3, and a black resin layer 4. The tin layer 1 has a thickness of 20 μm, the first metal layer 3 and the second metal layer 5 both have a thickness of 40 μm, the copper base layer 2 contains 99.95% copper, and the black resin layer 4 has a thickness of 10 μm. The first metal layer 3 and the second metal layer 5 are made of aluminum.

[0095] The preparation method of the above-mentioned black busbar for photovoltaic modules includes the following steps:

[0096] S1. Prepare copper substrate 2;

[0097] S2. Plate the first metal layer 3 and the second metal layer 5 on both sides of the copper base layer 2 respectively;

[0098] S3. A black resin layer 4 is disposed on the surface of the first metal layer 3;

[0099] S4. A tin layer 1 is plated on the surface of the second metal layer 5 using a back-to-back method;

[0100] S5. Corona treatment is performed on the black resin layer 4 to obtain a black busbar.

[0101] Example 4

[0102] This embodiment provides a black busbar for photovoltaic modules. The structure of the black busbar is the same as that in Embodiment 1, except that the surface of the black resin layer is provided with an uneven structure. The preparation method of the black busbar also includes providing an uneven structure on the surface of the black resin layer, and the black resin layer is not subjected to corona treatment.

[0103] Example 5

[0104] This embodiment provides a black busbar for photovoltaic modules. The structure of the black busbar is the same as that in Embodiment 3, except that the black resin layer is corona treated.

[0105] Example 6

[0106] This embodiment provides a photovoltaic module, including the black busbars for photovoltaic modules described in Embodiments 1-5. The manufacturing process of the photovoltaic module is as follows:

[0107] (1) The front EVA encapsulation film and the battery string are laid sequentially on the glass cover plate. The battery cells used in the battery string are half-cell 9-busbar double-sided PERC cells.

[0108] (2) After laying the battery string, the busbar (i.e. the black busbar in Example 1 or 2) is welded to the welding strip of the battery string;

[0109] (3) After welding is completed, EVA encapsulation film and TPT backplate are laid on the battery string in sequence, and the lead-out end of the busbar is passed through the opening of the EVA encapsulation film and TPT backplate to obtain the stacked part.

[0110] (4) The obtained laminated parts are laminated to obtain laminated parts;

[0111] (5) Install aluminum frames around the laminate, and then install junction boxes to obtain photovoltaic modules.

[0112] It should be noted that the above preparation method is the best solution obtained by the inventor after long-term and in-depth experimental research. Here, the inventor provides some solutions with poor results in the research process as comparative examples.

[0113] Comparative Example 1

[0114] This comparative example provides a black busbar for photovoltaic modules, such as... Figure 1 As shown, from top to bottom, it comprises: a tin layer 1, a copper base layer 2, a first metal layer 3, and a black resin layer 4. The tin layer 1 has a thickness of 20 μm, the first metal layer 3 has a thickness of 40 μm, the copper base layer 2 contains 99.95% copper, and the black composite resin 4 has a thickness of 10 μm. The first metal layer 3 is made of aluminum.

[0115] The preparation method of the above-mentioned black busbar for photovoltaic modules includes the following steps:

[0116] S1. Prepare copper substrate 2;

[0117] S2. A first metal layer 3 is disposed on one side of the copper base layer 2;

[0118] S3. Black composite resin 4 is disposed on the surface of the first metal layer 3;

[0119] S4. A tin layer 1 is plated on the surface of the copper base layer 2 using a back-to-back method to obtain a black busbar.

[0120] Comparative Example 2

[0121] This comparative example provides a black busbar for photovoltaic modules, comprising, from top to bottom, a tin layer, a copper substrate, a metal layer, and a black resin layer. The tin layer has a thickness of 20 μm, the metal layer has a thickness of 40 μm, the copper substrate contains 99.95% copper, and the black resin layer has a thickness of 10 μm. The metal layer is made of tin.

[0122] The preparation method of the above-mentioned black busbar for photovoltaic modules includes the following steps:

[0123] S1. Prepare the copper substrate;

[0124] S2. A metal layer is plated on both sides of the copper base layer;

[0125] S3. A black resin layer 4 is deposited on the surface of one side of the metal layer to obtain a black busbar.

[0126] Comparative Example 3

[0127] This comparative example provides a black busbar for photovoltaic modules, comprising a tin layer 1, a copper substrate 2, and a black resin layer 4 sequentially disposed thereon. The tin layer 1 has a thickness of 20 μm, the copper substrate 2 contains 99.95% copper, and the black resin layer 4 has a thickness of 10 μm. The material of the black resin layer is the same as in Example 1.

[0128] The busbars of Examples 1-5 and Comparative Examples 1-3 described above were applied to photovoltaic modules. The photovoltaic module manufacturing process is as follows:

[0129] (1) The front EVA encapsulation film and the battery string are laid sequentially on the glass cover plate. The battery cells used in the battery string are half-cell 9-busbar double-sided PERC cells.

[0130] (2) After laying the battery string, the busbar (i.e. the busbar in Examples 1-5 or Comparative Examples 1-3) is welded to the welding strip of the battery string;

[0131] (3) After welding is completed, EVA encapsulation film and TPT backplate are laid on the battery string in sequence, and the lead-out end of the busbar is passed through the opening of the EVA encapsulation film and TPT backplate to obtain the stacked part.

[0132] (4) The obtained laminated parts are laminated to obtain laminated parts;

[0133] (5) Install aluminum frames around the laminate, and then install junction boxes to obtain photovoltaic modules.

[0134] like Figure 4 The image shown is a front view of a photovoltaic module including the busbar of Comparative Example 1. A large area of ​​white bubbles is present near the bend of the busbar (the bubble clusters are circled in the image). Experiments revealed that photovoltaic modules including busbars of Comparative Examples 2 or 3 also exhibited numerous white bubble clusters near the bends of the busbars, indicating low adhesion between the black busbars of Comparative Examples 1-3 and the EVA film. This suggests that Comparative Examples 1 and 3, lacking corona treatment, exhibited low adhesion between the black resin layer and the photovoltaic module encapsulation film. In Comparative Example 2, the metal layer is a tin layer; during soldering, the tin melts and flows, weakening the adhesion between the black resin layer and the encapsulation film. The photovoltaic modules of Comparative Examples 1-3 do not meet quality standards and are either substandard or downgraded products.

[0135] like Figure 5The image shown is a front view of a photovoltaic module including the black busbar of Example 1. It can be seen that there are almost no air bubbles near the bend of the busbar, and it is transparent, indicating that the black busbar of Example 1 has high adhesion to the EVA film. Experiments showed that photovoltaic modules including the black busbars of Examples 2-5 also had almost no air bubbles near the busbars, indicating that the black busbars of Examples 2-5 have high adhesion to the EVA film. This demonstrates that corona treatment or the addition of an uneven structure on the black resin layer can improve the adhesion between the black busbar and the EVA film.

[0136] Using photovoltaic modules with black busbars as described in Example 1 and photovoltaic modules with black busbars as described in Comparative Example 3, 10 photovoltaic modules were fabricated respectively according to the steps described above. The initial output power of each photovoltaic module was tested. Then, the photovoltaic modules were placed in a test chamber with a temperature of 85°C and a humidity of 85% for 1000 hours, and the output power of each photovoltaic module was tested again. The power degradation rate was calculated according to the following formula:

[0137] (Initial output power - Post-test output power) / Initial output power × 100%

[0138] Among them, the power attenuation rate of 10 photovoltaic modules using the black busbar of Example 1 was in the range of 0.8% to 1.5%, and the power attenuation rate of 10 photovoltaic modules using the black busbar of Comparative Example 3 was in the range of 2.0% to 6.0%. It can be seen that the black busbar provided by the present invention prevents the copper base layer from being corroded by setting a high melting point first metal layer between the black resin layer and the copper base layer, thereby reducing the output power attenuation of the photovoltaic module.

[0139] Furthermore, the method for preparing the black busbar provided in this embodiment of the invention is simple, and the cost of the black resin layer and the first metal layer used is also low. Therefore, the cost of the black busbar provided in this embodiment of the invention does not increase significantly.

[0140] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a black busbar for photovoltaic modules, characterized in that, include: S1. Prepare the copper substrate (2); S2. A first metal layer (3) is provided on one side surface of the copper base layer (2); S3. A black resin layer (4) is provided on the surface of the first metal layer (3); S4. A tin layer (1) is plated on the other side of the copper base layer (2) using a back-to-back method; S5. A corona treatment is performed on the black resin layer (4) to obtain a black busbar; The black busbar comprises, in sequence: a tin layer (1), a copper base layer (2), a first metal layer (3), and a black resin layer (4), wherein the melting point of the first metal layer (3) is higher than that of the tin layer (1); The first metal layer (3) is aluminum, aluminum alloy, nickel or nickel alloy; during welding, the first metal layer will not melt and will not affect the adhesion between the black resin layer and the adhesive film; During use, the first metal layer can act as a barrier against moisture and oxygen, thereby protecting the copper base layer. The surface of the black resin layer (4) has an inverted pyramid-shaped protrusion; after the first metal layer (3) is formed, an uneven structure is formed on the surface of the first metal layer (3) by etching, and then the black resin layer (4) is formed on the first metal layer (3), so that the surface of the black resin layer (4) has an uneven structure. The thickness of the tin layer (1) is 15-25 μm; The thickness of the black resin layer (4) is 5-18 μm; The surface dyne value of the black resin layer (4) is 40 or higher.

2. The preparation method according to claim 1, characterized in that, The melting point of the first metal layer (3) is higher than 400°C; Preferably, the thickness of the first metal layer (3) is 40 to 800 μm.

3. The preparation method according to claim 1, characterized in that, The thickness of the tin layer (1) is 15-24 μm.

4. The preparation method according to claim 1, characterized in that, The thickness of the black resin layer (4) is 6 to 18 μm.

5. The preparation method according to claim 1, characterized in that, A second metal layer (5) is disposed between the tin layer (1) and the copper base layer (2); Preferably, the second metal layer (5) and the first metal layer (3) are made of the same material.

6. The preparation method according to claim 5, characterized in that, Preparation methods include: Step 1: Prepare the copper substrate (2); Step 2: Deposit a first metal layer (3) and a second metal layer (5) on both sides of the copper base layer (2); Step 3: Deposit a black resin layer (4) on the surface of the first metal layer (3); Step 4: Apply a tin layer (1) to the surface of the second metal layer (5) using a back-to-back method; Step 5: Perform corona treatment on the black resin layer (4) to obtain a black busbar; The melting point of the first metal layer (3) is higher than that of the tin layer (1).

7. A photovoltaic module, characterized in that, The black busbar for photovoltaic modules prepared by the preparation method according to any one of claims 1-6.

Images