Photovoltaic module and method for producing a photovoltaic module

Abstract

This application relates to the photovoltaic field, providing a photovoltaic module and a method for manufacturing the photovoltaic module. The photovoltaic module includes a solar cell, a first solder strip, and a busbar. The first solder strip is disposed on the back side of the solar cell. The busbar is located on the side of the first solder strip away from the solar cell, and the busbar is fixed to the first solder strip by welding. The busbar has a hole that penetrates both the front and back sides of the busbar, so that at least a portion of the first solder strip is exposed at the hole. The end of the busbar near the first solder strip has a receiving recess, which is located on one side of the hole and corresponds to the first solder strip. The photovoltaic module provided by this application at least helps to improve the problem of incomplete soldering or insufficient solder strength caused by the solder strip being blocked by the busbar in the prior art, making it impossible to inspect the soldering quality.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module manufacturing technology, and in particular to a photovoltaic module and a method for preparing a photovoltaic module. Background Technology

[0002] Currently, back-contact (BC) cells are a type of high-efficiency crystalline silicon solar cell technology. Its core feature is that all metal electrodes are placed on the back of the cell, with no grid lines obstructing the front, thereby improving the utilization and conversion efficiency of incident light. Specifically, in BC photovoltaic modules, both positive and negative polarity solder strips are laid on the back of the cell, and busbars are laid on top of the solder strips and welded to solder strips of the same polarity. This achieves a hidden arrangement of the busbars on the back of the cell, ensuring the integrity of the front appearance of the BC photovoltaic module and its superior photoelectric conversion efficiency.

[0003] However, since the solder strip is located below the busbar, the solder joint is covered by the busbar after welding, making it impossible to inspect the welding quality. Welding defects such as incomplete welding and desoldering between the solder strip and the busbar cannot be detected and controlled in a timely manner, posing potential risks to the long-term electrical performance stability and service life of BC photovoltaic modules. Summary of the Invention

[0004] This application provides a photovoltaic module and a method for manufacturing a photovoltaic module, which at least helps to improve the problem of incomplete welding or insufficient welding strength caused by the inability to inspect the welding quality due to the solder strip being blocked by the busbar in the prior art.

[0005] According to some embodiments of this application, one aspect of this application provides a photovoltaic module, including: a solar cell; a first solder strip disposed on the back side of the solar cell; a busbar located on the side of the first solder strip away from the solar cell, the busbar being fixed to the first solder strip by welding, the busbar having a hole penetrating the front and back sides of the busbar so that at least a portion of the first solder strip is exposed at the hole; wherein, the end of the busbar near the first solder strip has a receiving recess located on one side of the hole and corresponding to the first solder strip.

[0006] In some embodiments, the hole is a circular hole, and the diameter D1 of the circular hole satisfies: 1mm≤D1≤3mm.

[0007] In some embodiments, the hole is a circular hole, and there is a minimum distance D2 between the circular hole and the edge of the busbar. The minimum distance D2 and the diameter D1 of the circular hole satisfy the condition: 3D1≤D2.

[0008] In some embodiments, the battery cell is a back-contact battery cell; and / or, the welding is laser welding.

[0009] In some embodiments, there are multiple first solder strips, which are spaced apart on the battery cell along a preset direction; there are multiple holes, which are arranged one-to-one with the multiple first solder strips, and at least a portion of each first solder strip is exposed at its corresponding hole.

[0010] In some embodiments, the hole wall has an identification layer, the color of which is different from the color of the busbar.

[0011] In some embodiments, there are multiple receiving recesses, and the multiple receiving recesses are divided into at least two groups; wherein, along the extension direction of the first weld strip, the at least two groups of receiving recesses are located on opposite sides of the hole, each group of receiving recesses includes multiple receiving recesses, and the multiple receiving recesses in each group are arranged in an array along the extension direction of the first weld strip.

[0012] In some embodiments, the busbar has a thickness T along a direction perpendicular to the front side of the busbar, and the depth H of the recess and the thickness T satisfy the following condition: 0.1T≤H≤0.6T.

[0013] In some embodiments, the bottom wall of the recess is arc-shaped.

[0014] In some embodiments, the photovoltaic module further includes: a second solder strip disposed on the back side of the solar cell, with the second solder strip spaced apart from the first solder strip along a preset direction; and an insulating structure disposed between the second solder strip and the busbar for insulation.

[0015] According to some embodiments of this application, another aspect of this application provides a method for manufacturing a photovoltaic module. The method includes: laying a first solder strip on the back of a solar cell and welding the first solder strip to the solar cell; drilling a hole in a busbar to form a hole penetrating from the front to the back of the busbar; laser engraving a region on one side of the busbar to form a receiving recess at one end of the busbar; covering the end of the first solder strip away from the solar cell with the busbar so that at least a portion of the first solder strip is exposed at the hole; and welding the busbar to the first solder strip for fixation.

[0016] In some embodiments, after the busbar is welded and fixed to the first solder strip, the method for manufacturing a photovoltaic module further includes: acquiring a welding image at the hole; and determining whether the welding strength between the busbar and the first solder strip meets the welding requirements based on the welding image.

[0017] In some embodiments, determining whether the welding strength between the busbar and the first solder strip meets the welding requirements based on the welding image includes: extracting pixels of the solder area from the welding image to obtain the solder coverage area S1 inside the hole and the total area S0 of the hole opening; calculating the area ratio P = S1 / S0 of the solder coverage area S1 to the total area S0 of the hole opening; confirming that the welding strength between the busbar and the first solder strip meets the welding requirements when the area ratio P is greater than or equal to a preset threshold; and confirming that the welding strength between the busbar and the first solder strip does not meet the welding requirements when the area ratio P is less than the preset threshold.

[0018] The technical solution provided in this application has at least the following advantages:

[0019] When the worker welds the first weld strip and the busbar, at least part of the first weld strip is exposed at the hole of the busbar. During the welding process, the welding medium can flow into the hole. After the worker finishes welding, the weld morphology, solder filling state and fusion status inside the hole can be directly observed through the hole, thereby judging the welding status of the first weld strip and the busbar. This realizes the visualization and inspection of the welding quality between the first weld strip and the busbar, effectively solving the problem of incomplete welding or insufficient welding strength caused by the weld strip being blocked by the busbar in the prior art. This application is at least beneficial to improving the welding quality between the first weld strip and the busbar.

[0020] Meanwhile, the busbar has a receiving recess at one end near the first weld strip, and the receiving recess is located on one side of the observation hole and corresponding to the first weld strip. This allows part of the molten solder during the welding process between the first weld strip and the busbar to flow into and be contained in the receiving recess, thereby increasing the effective welding area between the busbar and the first weld strip, improving the welding strength between the busbar and the first weld strip, and enhancing the welding quality between the busbar and the first weld strip. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a structure of a photovoltaic module according to an embodiment of the present invention is shown;

[0023] Figure 2This illustrates the intention of placing a busbar at the end of a string of cells when a photovoltaic module has multiple cells.

[0024] Figure 3 A flowchart illustrating an embodiment of a method for manufacturing a photovoltaic module according to the present invention is shown. Detailed Implementation

[0025] As can be seen from the background art, the welding strip in the prior art is blocked by the busbar, which makes it impossible to inspect the welding quality, resulting in problems such as incomplete welding or insufficient welding strength.

[0026] To improve the welding quality between the solder strip and the busbar, this application provides a photovoltaic module and a method for manufacturing the photovoltaic module.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0031] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0032] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0033] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0034] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0035] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0036] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0037] This application provides a photovoltaic module and a method for manufacturing the photovoltaic module, which at least helps to improve the welding quality between the solder strip and the busbar.

[0038] like Figure 1 As shown, according to one aspect of an embodiment of this application, a photovoltaic module is provided. The photovoltaic module includes a solar cell 10, a first solder strip 20, and a busbar 30. The first solder strip 20 is disposed on the back side of the solar cell 10. The busbar 30 is located on the side of the first solder strip 20 away from the solar cell 10, and the busbar 30 is fixed to the first solder strip 20 by welding. The busbar 30 has a hole 31 that penetrates both the front and back sides of the busbar 30, so that at least a portion of the first solder strip 20 is exposed at the hole 31. The end of the busbar 30 near the first solder strip 20 has a receiving recess, which is located on one side of the hole 31 and corresponds to the first solder strip 20.

[0039] Using the technical solution in this embodiment, the first solder strip 20 of the photovoltaic module is disposed on the back side of the solar cell 10. A busbar 30 is located on the side of the first solder strip 20 away from the solar cell 10, and is fixed to the first solder strip 20 by welding. The busbar 30 has a hole 31 that penetrates both the front and back sides of the busbar 30, so that at least a portion of the first solder strip 20 is exposed at the hole 31. The end of the busbar 30 near the first solder strip 20 has a receiving recess, which is located on one side of the hole 31 and corresponds to the first solder strip 20. In this way, when the worker welds the first weld strip 20 and the busbar 30, at least part of the first weld strip 20 is exposed at the hole 31 of the busbar 30. During the welding process, the welding medium can flow into the hole 31. After the worker finishes welding, he can directly observe the weld point morphology, solder filling state and fusion status in the hole 31 through the hole 31, thereby judging the welding status of the first weld strip 20 and the busbar 30. This realizes the visualization and inspection of the welding quality between the first weld strip 20 and the busbar 30, effectively solving the problem of incomplete welding or insufficient welding strength caused by the weld strip being blocked by the busbar 30 in the prior art. This application is at least beneficial to improving the welding quality between the first weld strip 20 and the busbar 30. Meanwhile, the busbar 30 has a receiving recess at one end near the first weld strip 20, and the receiving recess is located on one side of the observation hole 31 and is corresponding to the first weld strip 20. This allows part of the molten solder during the welding process between the first weld strip 20 and the busbar 30 to flow into and be contained in the receiving recess, thereby increasing the effective welding area between the busbar 30 and the first weld strip 20, improving the welding strength between the busbar 30 and the first weld strip 20, and enhancing the welding quality between the busbar 30 and the first weld strip 20.

[0040] In this embodiment, the receiving recess of the busbar 30 is formed by laser engraving.

[0041] In some embodiments, hole 31 is a circular hole, and the diameter D1 of the circular hole satisfies: 1mm ≤ D1 ≤ 3mm. Maintaining the diameter of hole 31 on the busbar 30 within the range of 1mm to 3mm ensures, on the one hand, that hole 31 has sufficient opening area, facilitating visual inspection by workers or visual inspection systems to obtain clear welding images. This avoids inaccurate identification of solder coverage area, blurred image edges, or insufficient light affecting judgment accuracy due to excessively small hole diameters, thus ensuring the reliability and accuracy of welding quality detection within hole 31. On the other hand, it reduces the area occupied by hole 31, ensuring that busbar 30 has sufficient conductive area, reducing the resistance of busbar 30, and also ensuring that busbar 30 has a certain structural strength. This reduces the risk of damage to busbar 30 due to large hole diameters, ensuring the overall structural strength and safety of busbar 30.

[0042] In some embodiments, the hole 31 is a circular hole, and there is a minimum distance D2 between the circular hole and the edge of the busbar 30. The minimum distance D2 and the diameter D1 of the circular hole satisfy the condition: 3D1≤D2. This limitation on the ratio between the minimum distance D2 and the diameter D1 ensures sufficient width between the hole 31 and the edge of the busbar 30, reducing the possibility of a small width at the edge of the busbar 30 due to the hole 31 being close to the edge, thus reducing the likelihood of tearing or breakage at the edge of the busbar 30. Simultaneously, the sufficient edge width ensures that the conductive cross-sectional area of ​​the busbar 30 edge region is not affected by the hole 31, guaranteeing the current-carrying capacity of the busbar 30 during long-distance current transmission and ensuring the long-term reliability and safety of the photovoltaic module.

[0043] In some embodiments, the battery cell 10 is a back-contact battery cell 10; and / or, the welding is laser welding. In this way, both the positive and negative electrodes of the back-contact battery cell 10 are located on the back side of the battery cell 10, achieving a concealed arrangement of the first welding strip 20 and the busbar 30 on the battery cell 10, as both are located on the back side of the battery cell 10. Furthermore, compared to traditional electromagnetic welding, laser welding eliminates the need for mechanical pressure during the process, reducing damage to the battery cell 10 caused by welding head compression and ensuring the structural integrity of the battery cell 10. Additionally, laser welding offers advantages such as high energy density, small heat-affected zone, fast welding speed, and good weld consistency, which are beneficial for improving the welding quality and efficiency between the first welding strip 20 and the busbar 30.

[0044] In some embodiments, there are multiple first solder strips 20, which are spaced apart on the battery cell 10 along a preset direction; there are multiple holes 31, which are arranged one-to-one with the multiple first solder strips 20, and at least a portion of each first solder strip 20 is exposed at its corresponding hole 31. Thus, by correspondingly providing multiple holes 31 on the busbar 30 and one-to-one with each first solder strip 20, each welding position of the busbar 30 and the multiple first solder strips 20 has an independent hole 31, enabling independent detection and quality control of each welding point. This reduces the phenomenon of damage to the entire battery string due to single-point poor soldering, facilitates accurate positioning of rework points, and reduces rework costs. Simultaneously, the one-to-one correspondence between each observation hole 31 and each first solder strip 20 allows for precise identification and positioning of each welding position through a visual positioning system, providing a reliable physical reference for subsequent automated welding and automated optical inspection, improving the automation level of the production line and product consistency.

[0045] In this embodiment, the battery cell 10 is arranged in a sheet shape, and the preset direction is consistent with the length direction or width direction of the battery cell 10.

[0046] In some embodiments, the wall of the hole 31 has an identification layer, the color of which is different from the color of the busbar 30. This identification layer on the wall of the hole 31 facilitates quick location of the hole 31 by workers or visual inspection systems, allowing them to observe or inspect the coverage area of ​​the solder or the morphology of the solder joints within the hole 31, thus improving the efficiency of solder quality inspection.

[0047] In some embodiments, there are multiple receiving recesses, and the multiple receiving recesses are divided into at least two groups; wherein, along the extending direction of the first solder strip 20, at least two groups of receiving recesses are respectively located on opposite sides of the hole 31, each group of receiving recesses includes multiple receiving recesses, and the multiple receiving recesses in each group are arranged in an array along the extending direction of the first solder strip 20. In this way, the above arrangement can increase the area for receiving solder, thereby increasing the welding area between the first solder strip 20 and the busbar 30, improving the welding strength between the first solder strip 20 and the busbar 30, and also making the stress distribution on the welding interface more uniform, reducing the situation of stress concentration in a single solder joint area, and improving the welding quality between the first solder strip 20 and the busbar 30.

[0048] Optionally, the battery cell 10 has at least one flow channel, which is disposed between two adjacent receiving recesses, with each end of the flow channel connecting to one of the two adjacent receiving recesses. The flow channel is also formed by laser engraving. In this way, the flow channel can assist the flow of molten solder, which is beneficial to the stability of the weld between the first solder strip 20 and the busbar 30.

[0049] In some embodiments, the busbar 30 has a thickness T along a direction perpendicular to its front surface, and the depth H of the receiving recess satisfies the following relationship with the thickness T: 0.1T ≤ H ≤ 0.6T. This proportional relationship between the depth H of the receiving recess and the thickness T of the busbar 30 ensures, on the one hand, that the receiving recess has sufficient depth to allow the molten solder from the welding of the first solder strip 20 and the busbar 30 to effectively flow into and be contained within the recess, thus guaranteeing the welding strength between the first solder strip 20 and the busbar 30; on the other hand, it also ensures that the busbar 30 body retains a portion of its own thickness, guaranteeing the structural strength of the busbar 30 and reducing its resistance, thereby ensuring the conductivity reliability of the busbar 30.

[0050] Specifically, the width of the guide groove is smaller than the width of the opening of the recess; and / or, the depth of the guide groove is smaller than the depth H of the recess. In this way, the guide groove can reduce the area occupied by the battery cell 10 while achieving flow guidance, thus ensuring the structural strength and conductivity reliability of the battery cell 10.

[0051] In some embodiments, the bottom wall of the receiving recess is arc-shaped. This arc-shaped bottom wall, compared to a right-angled or sharp-angled bottom wall, effectively reduces stress concentration points at the bottom of the receiving recess, lowering the risk of cracks forming in the receiving recess area of ​​the busbar 30 under mechanical loads and thermal stress. Simultaneously, the arc-shaped bottom wall facilitates the uniform spreading of molten solder along the arc surface, improving the quality of the solder joint.

[0052] In some embodiments, the photovoltaic module further includes a second solder strip 40 and an insulating structure 50. The second solder strip 40 is disposed on the back side of the solar cell 10 and is spaced apart from the first solder strip 20 along a predetermined direction. The insulating structure 50 is disposed between the second solder strip 40 and the busbar 30 for insulation. Typically, the first solder strip 20 and the second solder strip 40 are soldered to the positive and negative electrodes of the solar cell 10, respectively. When the same busbar 30 crosses the back of the solar cell 10, it will inevitably pass through the first solder strip 20 and the second solder strip 40 in sequence. After the busbar 30 is soldered to the first solder strip 20, the insulating structure 50 is placed between the second solder strip 40 and the busbar 30 to physically isolate the second solder strip 40 from the busbar 30. This effectively prevents the risk of short circuit caused by the busbar 30 coming into contact with both the first solder strip 20 and the second solder strip 40, and ensures that the current of the first solder strip 20 and the second solder strip 40 flows into the corresponding polarity busbar 30 according to its designed path, thus ensuring the operational reliability of the photovoltaic module.

[0053] In this embodiment, the insulating structure 50 is made of insulating material.

[0054] Optionally, the insulation structure 50 is an insulation pad.

[0055] like Figure 2 As shown, multiple battery cells 10 are arranged in a predetermined direction. Adjacent battery cells 10 are connected in series by a first solder strip 20 to form a battery string. The busbar 30 is used to connect different battery strings and collect the current of each battery string before it is led out through the junction box.

[0056] like Figure 2 As shown, the busbar 30 is located at the end of the battery string, that is, the busbar 30 is welded to the first welding strip 20 that connects to the outermost battery cell 10 of the battery string.

[0057] Specifically, since the busbar 30 and the first solder strip 20 are made of metal, if they are directly exposed on the front or edge of the solar cell 10, it will affect the appearance and uniformity of the photovoltaic module. Therefore, the first solder strip 20 and the busbar 30 can be placed on the back of the solar cell 10.

[0058] Optionally, a black shielding film can be applied to the busbar 30 to shield it.

[0059] According to some embodiments of this application, another aspect of this application provides a method for preparing a photovoltaic module. This method is used to prepare the photovoltaic module as described above. Figure 3 As shown, the method for manufacturing a photovoltaic module includes: laying a first solder ribbon 20 on the back of a solar cell 10 and welding the first solder ribbon 20 to the solar cell 10; drilling a hole 31 in a busbar 30 to form a hole 31 penetrating from the front to the back of the busbar 30; performing laser engraving on a region of the busbar 30 located on one side of the hole 31 to form a receiving recess at one end of the busbar 30; covering the end of the first solder ribbon 20 away from the solar cell 10 with the busbar 30 so that at least a portion of the first solder ribbon 20 is exposed at the hole 31; and welding the busbar 30 to the first solder ribbon 20 for fixation. In this way, the welding of the first welding strip 20 to the battery cell 10, the processing of the opening 31 and the receiving recess of the busbar 30, the covering of the busbar 30 on the first welding strip 20, and the welding of the busbar 30 to the first welding strip 20 are completed in sequence, and the photovoltaic module is reliably manufactured in sequence, ensuring the smooth manufacturing of the photovoltaic module.

[0060] In some embodiments, after the busbar 30 is welded and fixed to the first solder strip 20, the photovoltaic module manufacturing method further includes: acquiring a welding image at the hole 31; and determining whether the welding strength between the busbar 30 and the first solder strip 20 meets the welding requirements based on the welding image. Thus, timely acquisition of the welding image at the hole 31 after the first solder strip 20 is welded and fixed to the busbar 30 enables real-time detection of the welding quality at the welding position, reducing the risk of defective products flowing into subsequent processes and improving product quality.

[0061] In this embodiment, the device for acquiring the welding image at hole 31 is an industrial camera.

[0062] In some embodiments, determining whether the welding strength between the busbar 30 and the first solder strip 20 meets the welding requirements based on the welding image includes: extracting pixels of the solder area from the welding image to obtain the solder coverage area S1 in the hole 31 and the total area S0 of the hole 31; calculating the area ratio P = S1 / S0 of the solder coverage area S1 to the total area S0 of the hole; confirming that the welding strength between the busbar 30 and the first solder strip 20 meets the welding requirements when the area ratio P is greater than or equal to a preset threshold; and confirming that the welding strength between the busbar 30 and the first solder strip 20 does not meet the welding requirements when the area ratio P is less than the preset threshold. In this way, by extracting pixels from the solder area of ​​the welding image and calculating the ratio between the solder coverage area S1 in the hole 31 and the total area S0 of the hole 31, a standard index for judging the welding quality of the first solder strip 20 and the busbar 30 is formed. Compared with judging based on human experience, pixel-level image analysis has high precision and high repeatability, and can identify tiny solder defects or uneven filling that are difficult for the human eye to detect, effectively reducing the missed judgment rate and improving the quality of the product leaving the factory.

[0063] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0064] The first solder strip of the photovoltaic module is disposed on the back of the solar cell. A busbar is located on the side of the first solder strip away from the solar cell, and the busbar is fixed to the first solder strip by welding. The busbar has a hole that penetrates both the front and back of the busbar, exposing at least a portion of the first solder strip. The end of the busbar near the first solder strip has a receiving recess located on one side of the hole and corresponding to the first solder strip. Thus, when the worker welds the first solder strip and the busbar, at least a portion of the first solder strip is exposed at the hole of the busbar. During welding, the welding medium can flow into the hole. After welding, the worker can directly observe the weld morphology, solder filling state, and fusion status through the hole, thereby judging the welding condition of the first solder strip and the busbar. This achieves visualization and inspection of the welding quality between the first solder strip and the busbar, effectively solving the problem of incomplete welds or insufficient welding strength caused by the solder strip being obscured by the busbar in the prior art. This application at least improves the welding quality between the first solder strip and the busbar. Meanwhile, the busbar has a receiving recess at one end near the first weld strip, and the receiving recess is located on one side of the observation hole and corresponding to the first weld strip. This allows part of the molten solder during the welding process between the first weld strip and the busbar to flow into and be contained in the receiving recess, thereby increasing the effective welding area between the busbar and the first weld strip, improving the welding strength between the busbar and the first weld strip, and enhancing the welding quality between the busbar and the first weld strip.

[0065] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that, include: Battery cells; The first solder strip is disposed on the back side of the solar cell; A busbar is located on the side of the first solder strip away from the battery cell. The busbar is fixed to the first solder strip by welding. The busbar has a hole that extends through the front and back of the busbar so that at least a portion of the first solder strip is exposed at the hole. The busbar has a receiving recess at one end near the first welding strip, and the receiving recess is located on one side of the hole and is corresponding to the first welding strip.

2. The photovoltaic module according to claim 1, characterized in that, The hole is a circular hole, and the diameter D1 of the circular hole satisfies: 1mm≤D1≤3mm.

3. The photovoltaic module according to claim 1, characterized in that, The hole is a circular hole, and there is a minimum distance D2 between the circular hole and the edge of the busbar. The minimum distance D2 and the diameter D1 of the circular hole satisfy the condition: 3D1≤D2.

4. The photovoltaic module according to claim 1, characterized in that, The battery cell is a back-contact battery cell; and / or, The welding is laser welding.

5. The photovoltaic module according to claim 1, characterized in that, There are multiple first solder strips, and the multiple first solder strips are spaced apart on the battery cell along a preset direction; There are multiple holes, and each of the multiple holes is provided in a one-to-one correspondence with a multiple of the first solder strips, with at least a portion of each of the first solder strips exposed at its corresponding hole.

6. The photovoltaic module according to claim 1, characterized in that, The hole wall has an identification layer, the color of which is different from the color of the busbar.

7. The photovoltaic module according to claim 1, characterized in that, The accommodating recess is multiple, and the multiple accommodating recesses are at least two groups; Wherein, along the extension direction of the first weld strip, at least two groups of the receiving recesses are respectively located on opposite sides of the hole, each group of the receiving recesses includes a plurality of receiving recesses, and the plurality of receiving recesses in each group are arranged in an array along the extension direction of the first weld strip.

8. The photovoltaic module according to claim 1, characterized in that, Along a direction perpendicular to the front of the busbar, the busbar has a thickness T, and the depth H of the receiving recess satisfies the following relationship with the thickness T: 0.1T≤H≤0.6T.

9. The photovoltaic module according to claim 1, characterized in that, The bottom wall of the recessed portion is arc-shaped.

10. The photovoltaic module according to claim 1, characterized in that, The photovoltaic module also includes: The second solder strip is disposed on the back side of the battery cell, and is spaced apart from the first solder strip along a preset direction; An insulating structure is provided between the second solder strip and the busbar for insulation.

11. A method for preparing a photovoltaic module, characterized in that, The method for preparing the photovoltaic module is used to prepare the photovoltaic module as described in any one of claims 1 to 10, and the method for preparing the photovoltaic module includes: The first solder strip is laid on the back of the battery cell, and the first solder strip is welded to the battery cell; A hole is drilled in the busbar to form a hole that extends from the front to the back of the busbar. Laser engraving is performed on the area of ​​the busbar located on one side of the hole to form a receiving recess at one end of the busbar; The busbar is placed over the end of the first solder strip away from the battery cell, so that at least a portion of the first solder strip is exposed at the hole; The busbar is welded and fixed to the first welding strip.

12. The method for preparing a photovoltaic module according to claim 11, characterized in that, After the busbar is welded and fixed to the first solder strip, the method for manufacturing the photovoltaic module further includes: Obtain the welding image at the hole; Based on the welding image, determine whether the welding strength between the busbar and the first welding strip meets the welding requirements.

13. The method for preparing a photovoltaic module according to claim 12, characterized in that, The step of determining whether the welding strength between the busbar and the first weld strip meets the welding requirements based on the welding image includes: Pixels of the solder region are extracted from the welding image to obtain the solder coverage area S1 inside the hole and the total area S0 of the hole opening; Calculate the area ratio P = S1 / S0 between the solder coverage area S1 and the total area S0 of the orifice; when the area ratio P is greater than or equal to a preset threshold, confirm that the welding strength between the busbar and the first solder strip meets the welding requirements; If the area ratio P is less than the preset threshold, it is confirmed that the welding strength between the busbar and the first welding strip does not meet the welding requirements.

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