A back contact cell shadow improvement method using a film heating

Abstract

The application provides a back contact cell shadow improvement film heating method, and relates to the technical field of photovoltaic modules. The back contact cell shadow improvement film heating method comprises the following steps: placing a cell sheet on a placing table in a heating chamber, and making the back surface of the cell sheet face upward; placing a solder strip corresponding to a soldering point position on the back surface of the cell sheet, so that the solder strip is in physical contact with the soldering point; after the solder strip is positioned, covering a skin film on the back surface of the cell sheet and the surface of the solder strip, so that the cell sheet, the solder strip and the skin film form a stacking structure from bottom to top; detachably installing a limiting tool on the placing table, exerting a downward pressure on the skin film in the area where the solder strip is located by the limiting tool, and limiting the solder strip; and applying heat by the heating chamber, so that the skin film is limitedly bonded with the solder strip and the cell sheet respectively. The application can relieve the problem of bulging during the covering process of the skin film, and improve the contact firmness between the skin film and the solder strip during the covering process.

Description

[0001] Cross-reference to related applications This application claims priority to Chinese Patent Application No. 2025104777188, filed on April 16, 2025, entitled "A Coating Heating Method for Improving Shadowing of Back Contact Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of photovoltaic module technology, and in particular to a coating heating method for improving the shading of back-contact cells. Background Technology

[0003] Back contact (BC) technology, also known as interdigitated back contact (IBC) solar cells, is a high-efficiency solar cell design. The following issues exist in the production of IBC modules: During the process of applying the skin film, contact heating (such as heating rollers) is usually used to attach the skin film to the battery cell, thereby fixing the solder strip to the battery cell. In this process, since both the front and back of the skin film are adhesive, contact heating cannot completely avoid removing the adhesive problem. This can easily lead to bulging of the skin film and poor contact between the skin film and the solder strip during the application process. Summary of the Invention

[0004] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and provide a coating heating method for improving the shadow of the back contact battery, which can alleviate the bulging problem during the skin film covering process and improve the contact firmness between the skin film and the solder strip during the covering process.

[0005] This application provides the following technical solution: This application provides a coating heating method for improving back contact battery shading, the coating heating method for improving back contact battery shading includes: Place the battery cells on a placement platform located in the heating chamber with the back of the battery cells facing upwards; According to the preset solder ribbon arrangement position, the solder ribbon is placed on the welding point position on the back of the battery cell so that the solder ribbon and the welding point form physical contact; After the solder ribbon is positioned, a skin film is applied to the back of the battery cell and the surface of the solder ribbon, forming a stacked structure from bottom to top; The limiting fixture is detachably installed on the placement platform. The limiting fixture applies downward pressure to the skin membrane in the area where the welding strip is located to limit the welding strip. In addition, heat is applied through the heating chamber to make the skin membrane form a limiting bond with the welding strip and the battery cell respectively.

[0006] In some embodiments, the end of the limiting tool facing the skin membrane has a protruding extrusion portion, which facilitates the contact between the extrusion portion of the limiting tool and the skin membrane. At least the surface of the extrusion portion that contacts the skin membrane is treated with low adhesion, such that the adhesive force between the extrusion portion and the skin membrane is less than the adhesive force between the skin membrane and the solder strip and the adhesive force between the skin membrane and the battery cell.

[0007] In some embodiments, the extrusion section has a limiting groove at one end facing the welding strip, the limiting groove extending along the extension direction of the welding strip, the limiting groove being used to accommodate and limit the corresponding welding strip; The extrusion part is located on the end face of both sides of the groove opening of the limiting groove and abuts against the skin membrane portion that directly contacts the battery cell. There are multiple extrusion parts, and a gap is defined between adjacent extrusion parts.

[0008] In some embodiments, the bottom of the limiting groove and the skin membrane on the welding strip are abutted together, and the bottom of the groove is provided with a vent hole that penetrates the limiting fixture, through which hot air is introduced.

[0009] In some embodiments, at least one protrusion is provided at the bottom of the limiting groove, and the protrusion abuts against the skin membrane on the welding strip.

[0010] In some embodiments, the protrusion is configured to extend along the extension direction of the limiting groove, and both sides of the protrusion are connected to the vent.

[0011] In some embodiments, the number of vent holes is set to multiple, and the multiple vent holes are spaced apart at least in the extending direction of the limiting groove.

[0012] In some embodiments, the vent has an extension formed within the limiting fixture.

[0013] In some embodiments, the heating chamber has an access channel, and the placement platform is configured to move along the extension direction of the access channel, allowing the placement platform to enter and exit the heating chamber.

[0014] In some embodiments, after the skin membrane is heated and bonded to the welding strip and the battery cell respectively, the limiting fixture is removed and the skin membrane is rolled.

[0015] The embodiments of this application have the following advantages: This application provides a coating heating method to improve the shadowing of back-contact batteries. It optimizes the coating process of the skin film by combining non-contact heating with mechanical positioning. Specifically, the battery cell is fixed with its back side facing upwards on a placement table within the heating chamber. The solder ribbon is precisely placed according to a preset ribbon layout, ensuring physical contact between the ribbon and the welding point on the back of the battery cell. After the ribbon is positioned, a skin film with double-sided adhesive is applied, forming a "battery cell-solder ribbon-skin film" stacked structure. A detachable positioning fixture applies downward pressure to the skin film in the ribbon area, preventing ribbon displacement and enhancing local adhesion. The heating chamber provides a uniform thermal field, causing the skin film to soften under pressure and form a strong, positioning adhesion with both the solder ribbon and the back of the battery cell, avoiding uneven adhesion or bulging problems caused by traditional heating roller contact.

[0016] Therefore, by applying uniform downward pressure through a limiting fixture, combined with non-contact heating, bulging caused by poor adhesion or uneven heating of the skin membrane is eliminated. Furthermore, the limiting fixture ensures close contact between the welding strip and the skin membrane, and the uniform heating in the heating chamber fully activates the adhesive material, significantly improving the bonding strength between the welding strip and the skin membrane. Moreover, by abandoning the traditional contact pressure application using heating rollers, friction or compression damage to the skin membrane surface is reduced, ensuring the integrity of the membrane layer.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a coating heating method for improving the shadow of a back contact battery in one embodiment; Figure 2 This is a schematic diagram of the overall structure of a support platform, gripper, and limiting fixture in one embodiment; Figure 3 This is a schematic diagram of the structure of a limiting tool in one embodiment; Figure 4 This is a schematic diagram of the structure of a limiting tool in another embodiment; Figure 5 This is a schematic diagram of the structure of a limiting tool in another embodiment; Figure 6 This is a schematic diagram of the assembly structure of the limiting tooling, support platform and heating chamber in one embodiment.

[0020] Explanation of key component symbols: 100-Gripper; 200-Placement stage; 300-Limiting fixture; 310-Extrusion section; 320-Limiting groove; 330-Ventilation hole; 340-Protrusion; 400-Support plate; 500-Heating chamber. Detailed Implementation

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] 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 one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] 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 in the template description is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] Among related technologies, back contact (BC) technology, also known as interdigitated back contact (IBC) solar cells, is a high-efficiency solar cell design. However, the following problems exist in the production of IBC cell modules: During the process of applying the skin film, contact heating (such as heating rollers) is usually used to attach the skin film to the battery cell, thereby fixing the solder strip to the battery cell. In this process, since both the front and back of the skin film are adhesive, contact heating cannot completely avoid removing the adhesive problem. This can easily lead to bulging of the skin film and poor contact between the skin film and the solder strip during the application process.

[0027] like Figure 1 and Figure 2 As shown, in order to solve the above-mentioned technical problems, this application provides a coating heating method for improving the shadow of the back contact battery. The coating heating method for improving the shadow of the back contact battery includes the following steps: Step S100: Place the battery cell on the placement platform 200 located in the heating chamber 500, with the back of the battery cell facing upwards.

[0028] In this embodiment, the battery cell is placed flat on the placement platform 200 located within the heating chamber 500, ensuring that the back of the battery cell faces upwards. This step prepares for subsequent placement of the solder ribbon and skin film application, requiring the battery cell to be kept stable on the placement platform 200.

[0029] For example, the upper end of the placement platform 200 has a support plane, the solar cell is square to the support plane, and the front side of the solar cell faces down to contact the support plane. Optionally, the support plane has a flexible layer and an elastic layer to act as a pressure buffer.

[0030] Step S200: According to the preset solder ribbon arrangement position, place the solder ribbon on the welding point position on the back of the battery cell so that the solder ribbon and the welding point form physical contact.

[0031] In this embodiment, according to the preset solder ribbon arrangement, the solder ribbons are placed on the corresponding welding points on the back of the battery cell, so that the solder ribbons and welding points make physical contact. Accurate solder ribbon positioning is one of the key steps to ensure the performance of the final product. Typically, each battery cell needs to be equipped with multiple solder ribbons, each solder ribbon is installed at a predetermined position on the battery cell, so that each solder ribbon can make contact with the corresponding welding point.

[0032] Step S300: After the solder ribbon is positioned, a skin film is applied to the back of the battery cell and the surface of the solder ribbon, and the battery cell, the solder ribbon and the skin film form a stacked structure from bottom to top.

[0033] In this embodiment, after precise positioning of the solder ribbon, a skin film is applied to the back of the battery cell and the surface of the solder ribbon, forming a bottom-up stacked structure of the battery cell, solder ribbon, and skin film. In other words, the solder ribbon is sandwiched between the skin film and the battery cell. This step requires special care to avoid air bubbles or wrinkles to ensure good adhesion.

[0034] For example, the gripper 100, in conjunction with the robotic arm, grasps and transfers the skin membrane. The gripper 100 exerts an adhesive force during grasping and then blows hot air in the opposite direction after the cell is placed. The hot air temperature is set to 100℃±5℃, thereby ensuring that the skin membrane adheres tightly to the battery cell and the solder ribbon.

[0035] For example, the gripper 100 includes an adsorption block with an adsorption portion. The contact end face of the adsorption portion has pores that communicate with a suction member. When adsorbing the skin membrane, the suction member draws out the gas from the pores, creating a negative pressure on the contact end face, thereby adsorbing the skin membrane. When the skin membrane is in place, hot air is introduced into the pores using the suction member to backflush the skin membrane, causing it to detach from the adsorption portion and adhere tightly to the battery cell and solder strip. The hot air softens the skin membrane, thereby improving the adhesion between the skin membrane and the solder strip and battery cell, respectively.

[0036] For example, the lower end of the adsorption block has multiple adsorption portions, which are spaced apart and all contact surfaces are located on the same plane. Alternatively, in other embodiments, the multiple adsorption portions include multiple first adsorption portions and multiple second adsorption portions. The multiple first adsorption portions are used to contact the portion of the skin film corresponding to the solder strip, and the multiple second adsorption portions are used to contact the portion of the skin film corresponding to the battery cell. There is a height difference between the contact surfaces of the first adsorption portions and the contact surfaces of the second adsorption portions. This height difference should be equal to the thickness of the solder strip, thereby further improving the adhesion effect of the skin film.

[0037] For example, the extraction component includes a bidirectional fan, a bidirectional air pump, or a bidirectional vacuum pump, etc., wherein a heating element is provided at the air inlet or outlet of the extraction component. During the backflushing process, the heating element (such as a heating wire) is activated to provide hot air. In other embodiments, the extraction component includes a first exhaust fan and a second exhaust fan. The first and second exhaust fans are connected to an air vent via a three-way reversing valve. The first exhaust fan is used to extract negative pressure from the air vent, and the second exhaust fan is used to extract hot air into the air vent. During the adsorption of the skin membrane, the first exhaust fan extracts gas from the air vent to create negative pressure adsorption, and the second exhaust fan is shut off. After the skin membrane is in place, the first exhaust fan is shut off, and the second exhaust fan is turned on to backflush the hot air. Optionally, the second exhaust fan is an electric heater, an electromagnetic fan, etc. Alternatively, a heating element, such as a heating wire, is provided at the air inlet or outlet of the second exhaust fan to heat the gas and form hot air.

[0038] Step S400: The limiting fixture 300 is detachably installed on the placement platform 200. The limiting fixture 300 applies downward pressure to the skin membrane in the area where the welding strip is located to limit the welding strip. In addition, heat is applied through the heating chamber 500 to make the skin membrane form a limiting bond with the welding strip and the battery cell respectively.

[0039] In this embodiment, the limiting fixture 300 is detachably mounted on the placement stage 200. The limiting fixture 300 applies uniform downward pressure to the skin membrane in the area where the solder ribbon is located, increasing the friction between the solder ribbon and the battery cell to limit the solder ribbon. Simultaneously, heat is applied through the heating chamber 500, allowing the skin membrane to soften and form a firm, limiting bond with both the solder ribbon and the back of the battery cell. This non-contact heating combined with mechanical limiting effectively avoids uneven bonding or bulging caused by traditional heating methods.

[0040] In other words, this application provides a coating heating method to improve the shadowing of back-contact batteries. It optimizes the coating process of the skin film by combining non-contact heating with mechanical positioning. Specifically, the battery cell is fixed with its back side facing upwards on a placement stage 200 within a heating chamber 500. The solder ribbon is precisely placed according to a preset ribbon layout, ensuring physical contact between the ribbon and the welding point on the back of the battery cell. After the ribbon is positioned, a skin film with double-sided adhesive is applied, forming a "battery cell-solder ribbon-skin film" stacked structure. A detachable positioning fixture 300 applies downward pressure to the skin film in the ribbon area, preventing ribbon displacement and enhancing local adhesion. The heating chamber 500 provides a uniform thermal field, causing the skin film to soften under pressure and form a strong, positioning bond with both the solder ribbon and the back of the battery cell, avoiding uneven adhesion or bulging problems caused by traditional heating roller contact.

[0041] Therefore, by applying uniform downward pressure through the limiting fixture 300, combined with non-contact heating, bulging caused by poor adhesion or uneven heating of the skin membrane is eliminated. Furthermore, the limiting fixture 300 ensures close contact between the welding strip and the skin membrane, while the uniform heating in the heating chamber 500 fully activates the adhesive material, significantly improving the bonding strength between the welding strip and the skin membrane. Moreover, by abandoning the traditional contact pressure application using heating rollers, friction or compression damage to the skin membrane surface is reduced, ensuring the integrity of the membrane layer.

[0042] like Figure 3 As shown, in some embodiments, the end of the limiting tooling 300 facing the skin membrane has a protruding extrusion portion 310, which facilitates the contact between the extrusion portion 310 of the limiting tooling 300 and the skin membrane. The surface of the extrusion portion 310 that is in contact with the skin membrane is treated with low adhesion, so that the adhesive force between the extrusion portion 310 and the skin membrane is less than the adhesive force between the skin membrane and the welding strip and the adhesive force between the skin membrane and the battery cell.

[0043] In these embodiments, it is ensured that no unnecessary adhesion or damage is caused to the skin membrane during the application of pressure. Specifically, the end of the limiting tooling 300 facing the skin membrane has a pressing portion 310 formed by a protrusion 340, which directly contacts and applies pressure to the skin membrane. To optimize this process, at least the surface of the pressing portion 310 in contact with the skin membrane is treated with a low-adhesion treatment.

[0044] The purpose of this treatment is to reduce unnecessary adhesion: by reducing the adhesive force between the extrusion part 310 and the skin membrane, it is possible to avoid tearing of the skin membrane or residual adhesive when removing the limiting fixture 300. This ensures that the skin membrane remains intact on the battery cell and solder strip.

[0045] Since the adhesive force between the extrusion section 310 and the skin membrane is less than that between the skin membrane and the solder ribbon, and between the skin membrane and the battery cell, this ensures that during the heating process, the skin membrane tends to form a strong bond with the solder ribbon and the battery cell, rather than adhering to the limiting fixture 300.

[0046] This method not only improves the accuracy and reliability of the lamination process but also reduces problems in subsequent processing steps, such as cleaning the limit fixture 300 or repairing defects caused by improper adhesion. Furthermore, this design helps improve production efficiency by reducing downtime or other production interruptions caused by the fixture adhering to the skin film.

[0047] For example, at least the surface of the extrusion portion 310 that is in contact with the skin membrane is provided with a low surface energy coating, the surface energy of which is ≤25 mN / m. Optionally, the low surface energy coating is selected from at least one of polytetrafluoroethylene (PTFE), diamond-like carbon (DLC), or silicone release agent.

[0048] Alternatively, the surface of the extrusion part 310 that contacts the skin membrane is provided with a micro-nano structure, wherein the roughness Ra of the micro-nano structure is 0.1-10 μm and the contact area ratio is ≤30%.

[0049] Alternatively, the extrusion section 310 may be integrally formed from a non-sticky material, such as PTFE, PEEK, or ultra-high molecular weight polyethylene (UHMWPE).

[0050] like Figure 3 As shown, in some embodiments, the extrusion section 310 has a limiting groove 320 at one end facing the welding strip. The limiting groove 320 extends along the extension direction of the welding strip and is used to accommodate and limit the corresponding welding strip. The extrusion part 310 is located on the end face of both sides of the groove opening of the limiting groove 320 and abuts against the skin membrane portion that directly contacts the battery cell. There are multiple extrusion parts 310, and a gap is defined between adjacent extrusion parts 310.

[0051] In these embodiments, the structure of the limiting fixture 300 is further refined to more precisely adapt to and optimize the production process of back contact (BC) or interdigitated back contact (IBC) solar cell modules. Specifically, the end of the extrusion section 310 facing the solder strip is designed with a limiting groove 320, and since there are multiple solder strips, there are multiple extrusion sections 310, with gaps between adjacent extrusion sections 310. Typically, multiple solder strips are arranged side by side.

[0052] The extrusion section 310 has positioning grooves 320 at the end facing the weld strip, and these positioning grooves 320 are arranged along the extension direction of the weld strip. The main function of the positioning grooves 320 is to accommodate and position the corresponding weld strip, ensuring that the weld strip remains in the correct position throughout the coating process. That is, the groove wall of the positioning groove 320 contacts and positions the corresponding side of the weld strip. For example, the groove width of the positioning groove 320 is slightly larger than the width of the weld strip to accommodate the weld strip covered with the skin film.

[0053] The extrusion section 310 has its end faces on both sides of the opening of the limiting groove 320 directly abutting against the skin film portion covering the battery cell. This design allows the extrusion section 310 to apply uniform pressure to the skin film, while the limiting groove 320 fixes the position of the solder ribbon, preventing it from moving. For example, if the width of the solder ribbon is W1, the thickness of the skin film is W2, and the width of the limiting groove 320 is W3, then 0.1 ≤ W3 - 2 x W2 - W1 ≤ 0.5.

[0054] There are multiple extrusion sections 310, and gaps are defined between adjacent extrusion sections 310. This layout not only ensures that the welding strip can be effectively fixed and positioned, but also allows for a certain degree of flexibility, avoiding excessive pressure or damage to the skin membrane or welding strip, reducing the contact area between the limiting tooling 300 and the skin membrane, and the gaps between adjacent extrusion sections 310 form ventilation channels, allowing hot air in the heating chamber 500 to directly enter the ventilation channels, thereby rapidly heating the skin membrane.

[0055] For example, there is a gap between the bottom of the limiting groove 320 and the skin membrane on the welding strip, which facilitates the flow of hot air and forms a two-end pressing structure at both ends of the skin membrane on the welding strip, which helps to improve the adhesion between the skin membrane and the welding strip.

[0056] Clearly, the limiting groove 320 ensures that the solder strip can be accurately placed in its predetermined position, improving the precision and consistency of the entire module production. Applying pressure to the skin film via the extrusion section 310, especially during heating, promotes tight adhesion between the skin film and the solder strip and the solar cells, reducing bulging and other defects. The gap design between the multiple extrusion sections 310 helps to distribute pressure, avoiding unnecessary damage to the skin film or solder strip, while also facilitating hot air circulation and ensuring uniform heating.

[0057] like Figure 4 As shown, in some embodiments, the bottom of the limiting groove 320 is abutted against the skin membrane on the welding strip, and the bottom of the groove is provided with a vent hole 330 that penetrates the limiting fixture 300, through which hot air is introduced.

[0058] In these embodiments, the design of the limiting fixture 300 is further optimized to enhance the treatment effect on the solder strip and the skin membrane. Specifically, the bottom of the limiting groove 320 is in direct contact with the skin membrane on the solder strip, and the bottom of the groove is provided with vent holes 330 penetrating the limiting fixture 300, through which hot air can be introduced into the skin membrane.

[0059] The limiting groove 320 is not only used to fix the position of the solder strip, but its bottom is also designed to directly contact the skin membrane covering the solder strip. The purpose of this is to more precisely control the pressure applied to the skin membrane and ensure that the skin membrane can adhere evenly to the surface of the solder strip.

[0060] Ventilation holes 330, extending through the entire limiting fixture 300, are provided at the bottom of the limiting groove 320. These ventilation holes 330 allow heated air (hot air) to pass through and act directly on the skin membrane. This helps soften the skin membrane, allowing it to better adhere to the solder ribbon and battery cell, while also helping to remove any air bubbles or wrinkles that may be present, thus improving the bonding quality. Furthermore, when removing the limiting fixture 300, hot air can be maintained to create a backflushing effect, which facilitates the separation between the skin membrane and the limiting fixture 300, reducing the probability of air bubble formation.

[0061] Therefore, by directly applying hot air blown from the vent 330 to the skin membrane, the material can be effectively softened, allowing it to adhere more tightly to the solder strip and battery cell, significantly improving the quality and performance of the final product.

[0062] Furthermore, the vent 330 allows for more even heat distribution, avoiding localized overheating or underheating, which helps to create a more consistent bonding effect and reduces the occurrence of bulging.

[0063] like Figure 5 As shown, in some embodiments, at least one protrusion 340 is provided at the bottom of the limiting groove 320, and the protrusion 340 abuts against the skin membrane on the welding strip.

[0064] In these embodiments, the pressure distribution and adhesion of the skin membrane during the production of back contact (BC) or interdigitated back contact (IBC) solar cell modules are further optimized.

[0065] At least one protrusion 340 is provided at the bottom of the limiting groove 320, and these protrusions 340 directly contact the skin membrane covering the solder strip. The protrusions 340 are designed to concentrate the pressure on the critical area when pressure is applied, ensuring a tight fit between the skin membrane and the solder strip, and reducing the contact area.

[0066] The shape of the protrusion 340 can be circular, strip-shaped, or other geometric shapes, depending on the width and arrangement of the solder strip. The number of protrusions 340 can also be adjusted according to actual needs; for example, one or more protrusions 340 can be provided in each limiting groove 320.

[0067] The height of the 340mm protrusion should be precisely designed to ensure that it can apply sufficient pressure to the skin membrane without excessively squeezing it, which could cause the material to deform or be damaged.

[0068] like Figure 5As shown, in some embodiments, the protrusion 340 is configured to extend along the extension direction of the limiting groove 320, and both sides of the protrusion 340 are connected to the vent 330.

[0069] In some embodiments, the number of the vent holes 330 is set to be multiple, and the multiple vent holes 330 are spaced apart at least in the extending direction of the limiting groove 320.

[0070] In these embodiments, further optimization of the limiting groove 320, particularly the layout of the protrusion 340 and the vent 330, not only improves the uniformity of pressure distribution on the skin membrane but also enhances the flow of hot air through the multiple vents 330, thereby better promoting the bonding quality between the skin membrane and the solder ribbon and battery cells.

[0071] The protrusion 340 is designed to extend along the extension direction of the limiting groove 320, forming a strip-shaped or elongated structure. This design allows the protrusion 340 to apply pressure evenly throughout the entire solder strip area, ensuring a continuous and strong bond between the skin membrane and the solder strip.

[0072] Both sides of the protrusion 340 are connected to the vent 330, meaning that hot air can enter the spaces on both sides of the protrusion 340 through the vent 330 and act evenly on the skin membrane. This design ensures that the hot air can cover the entire width of the solder strip, avoiding problems of insufficient or excessive local heating.

[0073] The number of vent holes 330 is set to multiple, and these vent holes 330 are distributed at intervals at least in the extension direction of the limiting groove 320. This arrangement can ensure the uniform distribution of hot air throughout the welding strip area, improve heating efficiency, and reduce heat loss.

[0074] In some embodiments, the bottom of the limiting groove 320 is configured as an arc-shaped structure.

[0075] In some embodiments, the vent 330 has an extension formed within the limiting fixture 300.

[0076] In these embodiments, the vent 330 is designed with an extension within the limiting fixture 300, which can further optimize the flow path and distribution of hot air. This design, by adjusting the internal structure of the vent 330, allows the hot air to act more effectively on the skin membrane, improving heating uniformity and efficiency.

[0077] The vent 330 not only penetrates the surface of the limiting fixture 300, but also forms an extension section inside the limiting fixture 300.

[0078] These extensions can be designed in different shapes and lengths as needed, such as straight, L-shaped, or spiral, to adapt to specific process requirements.

[0079] The design of the extension section helps to optimize the flow path of the hot air, ensuring that the hot air can form a more complex flow pattern inside the limiting fixture 300 to heat the limiting fixture 300, thereby acting evenly on different areas of the skin membrane.

[0080] The optimal heating effect can be achieved by adjusting the speed and pressure distribution of the hot air by changing the direction and length of the extension section.

[0081] Multiple air outlets are installed at the end of the extension section or along the way, so that hot air can be blown onto the skin membrane from different angles and positions to enhance its softening effect.

[0082] For example, the air outlet can be designed as a slit, a circle, or other shapes, depending on the required pressure and coverage.

[0083] like Figure 6 As shown, in some embodiments, the heating chamber 500 has an access channel, and the placement platform 200 is configured to move along the extension direction of the access channel, so that the placement platform 200 can enter and exit the heating chamber 500.

[0084] In these embodiments, the heating chamber 500 is equipped with an access channel that allows the placement table 200 to move along the extension direction of the channel. This enables the placement table 200 to easily enter and exit the heating chamber 500, facilitating the connection between preceding and subsequent processes, such as material loading, installation of the limiting fixture 300, film heating, removal of the limiting fixture 300, and subsequent processing.

[0085] The placement table 200 is designed to move along the inlet / outlet channel, typically via an electric or hydraulic drive system. This movable placement table 200 not only increases production flexibility but also allows for adjustment of heating time as needed, optimizing the entire production process.

[0086] Clearly, the combination of the heating chamber 500's inlet and outlet channels and the movable placement platform 200 enables a more automated production line layout, reduces manual intervention, and improves overall production efficiency.

[0087] For example, the placement platform 200 has dimensions of 600mm x 600mm and an access channel length of 2m. The heating chamber 500 is equipped with a guide rail, and the placement platform 200 moves along the guide rail by a motor to enter and exit the heating chamber 500.

[0088] For example, it also includes a loading platform, in which the gripper 100 cooperates with the robotic arm to adsorb and transfer the battery cells and skin membrane on the loading platform, so as to place them on the placement platform 200 according to the above configuration.

[0089] In some embodiments, after the skin membrane is heated and bonded to the welding strip and the battery cell respectively, the limiting fixture 300 is removed and the skin membrane is rolled.

[0090] In these embodiments, after the skin membrane is heat-bonded to the solder ribbon and the battery cell respectively, the limiting fixture 300 is removed and the skin membrane is rolled. This process aims to further enhance the adhesion between the skin membrane and the solder ribbon and battery cell, and to ensure the high quality and flatness of the final product.

[0091] Inside the heating chamber 500, the skin membrane is softened by a non-contact heating method and forms a strong bond with the solder ribbon and battery cell under pressure.

[0092] After the heat bonding is completed, the limiting fixture 300 must be carefully removed first. This step requires the operator or automated equipment to operate accurately and gently to avoid any damage or deformation to the bonded skin membrane.

[0093] After removing the limiting fixture 300, the skin membrane is rolled using a rolling device. The rolling device typically contains one or more rollers that roll smoothly under pressure, applying uniform pressure to the skin membrane. This further enhances the adhesion between the skin membrane and the solder strip and battery cell; helps remove any air bubbles or wrinkles, ensuring a smooth surface; and allows for the inspection and correction of any minor imperfections.

[0094] Clearly, the rolling process increases the actual contact area between the coating and the solder strip and battery cells, thereby improving the bond strength between them. By applying uniform pressure, rolling helps to expel air from under the coating, reduce bulges and wrinkles, and ensure the quality of the coating.

[0095] Rolling can also help adjust the position of the skin membrane, making it fit more tightly onto the solder ribbon and cell, and improving the surface flatness of the entire module.

[0096] For example, selecting appropriate roller materials and shapes (such as rubber, silicone, etc.) can adapt to specific production process requirements. In some cases, rollers with different hardness are needed to achieve the desired rolling effect.

[0097] like Figure 6 As shown, in some embodiments, the belt conveyor constitutes the placement platform 200. The belt conveyor passes through the access channel, and the battery cells, solder ribbons, and skin membranes are stacked sequentially on the conveyor section of the conveyor belt, so that the stacked structure formed by the battery cells, solder ribbons, and skin membranes can enter and exit the heating chamber 500.

[0098] The conveyor belt mechanism has a support plate 400, and the conveying section of the conveyor belt is located on the support plate 400 to support the stable movement of the conveying section. The support plate 400 and the limiting fixture 300 are magnetically attracted to each other, thereby ensuring that the conveying process of the stacked structure is kept in a compressed state.

[0099] For example, one of the support plate 400 and the limiting fixture 300 may be integrally magnetic, while the other may be made of a magnetically conductive material. Alternatively, one of the support plate 400 or the limiting fixture 300 may have a magnet embedded in it, while the other may be made of a magnetically conductive material. Alternatively, an electromagnet may be provided within the support plate 400, and the limiting fixture 300 may be made of a magnetically conductive material (such as iron), enabling the generation of a magnetic field through on / off operation, thus producing a magnetic attraction force on the limiting fixture 300. Of course, the magnitude of the magnetic attraction force can also be adjusted by regulating the current of the electromagnet, thereby adjusting the downward pressure of the limiting fixture 300.

[0100] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0101] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0102] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. 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 modifications and improvements all fall within the protection scope of this application.

Claims

1. A back contact cell shadow improvement method of film heating, characterized by, The coating heating method for improving back contact battery shading includes: Place the battery cells on a placement platform located in the heating chamber with the back of the battery cells facing upwards; According to the preset solder ribbon arrangement position, the solder ribbon is placed on the welding point position on the back of the battery cell so that the solder ribbon and the welding point form physical contact; After the solder ribbon is positioned, a skin film is applied to the back of the battery cell and the surface of the solder ribbon, forming a stacked structure from bottom to top; The limiting fixture is detachably installed on the placement platform. The limiting fixture applies downward pressure to the skin membrane in the area where the welding strip is located to limit the welding strip. In addition, heat is applied through the heating chamber to make the skin membrane form a limiting bond with the welding strip and the battery cell respectively.

2. The back contact cell shadow improvement lamination heating method according to claim 1, characterized by, The limiting tooling has a protruding extrusion portion at one end facing the skin membrane, which facilitates the contact between the extrusion portion of the limiting tooling and the skin membrane. At least the surface of the extrusion portion that contacts the skin membrane is treated with low adhesion, so that the adhesion force between the extrusion portion and the skin membrane is less than the adhesion force between the skin membrane and the welding strip and the adhesion force between the skin membrane and the battery cell.

3. The back contact cell shadow improvement lamination heating method according to claim 2, characterized by, The extrusion section has a limiting groove at one end facing the welding strip. The limiting groove extends along the extension direction of the welding strip and is used to accommodate and limit the corresponding welding strip. The extrusion part is located on the end face of both sides of the groove opening of the limiting groove and abuts against the skin membrane portion that directly contacts the battery cell. There are multiple extrusion parts, and a gap is defined between adjacent extrusion parts.

4. The back contact cell shadow improvement lamination heating method according to claim 3, characterized by, The bottom of the limiting groove and the skin membrane on the welding strip are brought into contact. The bottom of the groove is provided with a vent hole that penetrates the limiting fixture, and hot air is introduced into the vent hole.

5. The back contact cell shadow improvement lamination heating method according to claim 4, characterized by, At least one protrusion is provided at the bottom of the limiting groove, and the protrusion abuts against the skin membrane on the welding strip.

6. The back contact cell shadow improvement lamination heating method according to claim 5, characterized by, The protrusion is configured to extend along the extension direction of the limiting groove, and both sides of the protrusion are connected to the vent.

7. The back contact cell shadow improvement lamination heating method according to claim 6, characterized by, The number of the vent holes is set to multiple, and the multiple vent holes are spaced apart at least in the extending direction of the limiting groove.

8. The back contact cell shadow improvement lamination heating method of claim 4, wherein, The vent hole has an extension section formed within the limiting fixture.

9. The back contact cell shadow improvement lamination heating method of claim 1, wherein, The heating chamber has an access channel, and the placement platform is configured to move along the extension direction of the access channel, so that the placement platform can enter and exit the heating chamber.

10. The back contact cell shadow improvement lamination heating method of claim 1, wherein, After the skin membrane is heated and bonded to the welding strip and the battery cell respectively, the limiting fixture is removed and the skin membrane is rolled.

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