Preparation method of back contact battery assembly and back contact battery assembly

Abstract

The invention relates to the field of solar cells, and provides a preparation method of a back contact cell module and the back contact cell module. The preparation method of the back contact battery assembly comprises the following steps: providing a carrier film; welding strips are arranged on a plurality of preset areas on the carrier film respectively, the carrier film is subjected to first heating treatment, and the preset areas are sequentially distributed in an adjacent mode in the first direction; a back contact battery piece is arranged on the portion, in each preset area, of the welding strip, secondary heating treatment is conducted on the carrier film, the temperature of the secondary heating treatment is higher than that of the primary heating treatment, and the multiple preset areas correspond to the multiple back contact battery pieces in a one-to-one mode. According to the invention, the technical problem of low production efficiency of the back contact battery assembly in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of solar cells, and more particularly, to a method for manufacturing a back-contact battery module and a back-contact battery module. Background Art

[0002] In order to further improve the power generation efficiency of back-contact battery modules, the prior art has adopted the zero busbar (0BB) technology in the manufacturing method of back-contact battery modules.

[0003] Currently, there are mainly three technical routes for the zero busbar (0BB) technology: dispensing / printing glue, laminating film, and high-temperature welding + dispensing. Among them, for dispensing / printing glue, glue dots are first dispensed or printed onto the battery cells, and then the welding tapes are placed, and good contact between the welding tapes and the battery cells is formed through the glue dots. In the laminating film route, after the welding tapes are laid on the battery cells, a layer of carrier film is laminated on the welding tapes, and the carrier film is melted to fix the welding tapes on the battery cells. The high-temperature welding + dispensing route uses the infrared welding method, and after welding is completed, glue is dispensed / printed above the welding wires to improve the bonding force between the welding tapes and the battery cells.

[0004] However, the production efficiency of back-contact battery modules is relatively slow when adopting the above technical routes of the zero busbar (0BB) technology, and there is an urgent need for a method for manufacturing a back-contact battery module with a relatively high production efficiency. Summary of the Invention

[0005] The main objective of the present invention is to provide a method for manufacturing a back-contact battery module and a back-contact battery module, so as to solve the technical problem of relatively slow production efficiency of back-contact battery modules in the prior art.

[0006] To achieve the above objective, according to one aspect of the present invention, there is provided a method for manufacturing a back-contact battery module. The back-contact battery module includes a plurality of back-contact battery cells. The method for manufacturing the back-contact battery module includes: providing a carrier film; respectively disposing welding tapes in a plurality of predetermined regions on the carrier film, and performing a first heat treatment on the carrier film. The plurality of predetermined regions are sequentially adjacently distributed along a first direction; disposing back-contact battery cells on the welding tapes in each predetermined region, and performing a second heat treatment on the carrier film. The temperature of the second heat treatment is higher than that of the first heat treatment. The plurality of predetermined regions correspond to the plurality of back-contact battery cells one by one.

[0007] Further, after respectively disposing the welding tapes in the plurality of predetermined regions on the carrier film and before performing the first heat treatment on the carrier film, the method for manufacturing the back-contact battery module further includes: fixing the welding tapes by using a welding tape pressing device.

[0008] Further, fixing the welding tapes by using a welding tape pressing device includes: placing the welding tape pressing device on the welding tapes; applying pressure to the welding tape pressing device until the welding tapes are attached to the carrier film.

[0009] Further, after disposing the back-contact solar cells on the solder tapes in each predetermined region and before performing the second heat treatment on the carrier film, the method for manufacturing a back-contact solar cell module further includes: fixing the back-contact solar cells by using a solar cell pressing device.

[0010] Further, fixing the back-contact solar cells by using a solar cell pressing device includes: placing the solar cell pressing device on the back-contact solar cells; applying pressure to the solar cell pressing device until the back-contact solar cells are in conformity with the solder tapes.

[0011] Further, the temperature of the first heat treatment is 80 to 90 °C, and the heating time of the first heat treatment is 1 to 2 s.

[0012] Further, the temperature of the second heat treatment is 120 to 130 °C, and the heating time of the second heat treatment is 1 to 3 s.

[0013] Further, in a case where a plurality of back-contact solar cells are arranged side by side in a first direction, the length of the carrier film in the first direction is greater than or equal to the total length of the plurality of back-contact solar cells in the first direction.

[0014] Further, each back-contact solar cell is in contact connection with at least two solder tapes which are disposed at intervals; in the first direction, each back-contact solar cell is connected to a previous back-contact solar cell through one of the solder tapes and connected to a subsequent back-contact solar cell through the other solder tape.

[0015] To achieve the above object, according to one aspect of the present invention, there is provided a back-contact solar cell module which is manufactured by using any one of the methods for manufacturing a back-contact solar cell module as described above.

[0016] The following beneficial effects are achieved through this application: By applying the technical solution of the present invention, a preparation method of a back-contact battery assembly is provided. This preparation method first provides a carrier film, and then, solder tapes are respectively arranged in a plurality of predetermined areas on the carrier film, realizing one-time film covering or integrated film covering of the solder tapes of the back-contact battery assembly. Therefore, compared with the film covering process in the prior art, the preparation method of this application greatly improves the film covering efficiency. Moreover, after the solder tapes are arranged on the carrier film in this application, the carrier film is subjected to a first heat treatment. The heat treatment can soften the carrier film and pre-fix the solder tapes laid on the carrier film, thus improving the problem that the solder tapes will shift during the preparation of the back-contact battery assembly. Among them, the above-mentioned plurality of predetermined areas correspond one-to-one with the plurality of back-contact battery cells in the back-contact battery assembly. After that, back-contact battery cells are arranged on the solder tapes in each of the above-mentioned predetermined areas, and the carrier film is subjected to a second heat treatment. As described above, when the solder tapes have been arranged in all the plurality of predetermined areas of the carrier film, the back-contact battery cells and the solder tapes on the carrier film can directly achieve electrical connection under the conditions of the above-mentioned second heat treatment without the need for welding. Therefore, compared with the prior art, this application omits the step of high-temperature welding, further significantly improving the production efficiency of the back-contact battery assembly. Moreover, the softening and melting of the carrier film can tightly wrap and bond the connection between the solder tapes and the back-contact battery cells, thus further improving the electrical connection stability and reliability between the solder tapes and the back-contact battery cells. In addition, after the back-contact battery cells are placed on the solder tapes, this application also raises the temperature on the basis of the temperature of the first heat treatment and uses the raised temperature to perform the second heat treatment on the carrier film, enabling deep bonding between the carrier film, the solder tapes, and the back-contact battery cells, and enabling the integrated structure of the solder tapes and the carrier film to be tightly combined with the battery cells, thereby further enhancing the mechanical strength between the solder tapes and the back-contact battery cells and improving the production yield and overall quality of the back-contact battery assembly. In summary, compared with the conventional film covering process, dispensing / printing process, and high-temperature welding + dispensing process in the prior art, this application significantly improves the production efficiency of the back-contact battery assembly and the welding quality problem between the solder tapes and the back-contact battery cells in the back-contact battery assembly, thus solving the technical problem of slow production efficiency of the back-contact battery assembly in the prior art.

[0017] In summary, through this application, the technical problem of slow production efficiency of the back-contact battery assembly in the prior art is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments and descriptions thereof of the invention are used to explain the invention and do not constitute an improper limitation of the invention. In the drawings:

[0019] Figure 1 The figure shows a flowchart of a method for manufacturing a back-contact battery assembly provided according to an embodiment of the present application;

[0020] Figure 2 The figure shows a process schematic diagram of setting a welding tape on a carrier film and setting a back-contact battery cell on the welding tape in a method for manufacturing a back-contact battery assembly provided according to an embodiment of the present application;

[0021] Figure 3 The figure shows a flowchart of a method for manufacturing a back-contact battery assembly provided according to a specific embodiment of the present application. Detailed implementation manners

[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0023] It should be pointed out that the following detailed description is exemplary and is intended to provide further illustration of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0024] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of the described features, steps, operations, devices, components, and / or their combinations.

[0025] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of the present invention described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0026] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element can be directly on the other element, or there can also be intermediate elements. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element can be "directly connected" to the other element, or "connected" to the other element through a third element.

[0027] The following further describes the present application in detail with specific embodiments, which should not be construed as limiting the scope claimed by the present application.

[0028] During the manufacturing process of photovoltaic cells, the function of metal grid lines (including main grids and fine grids) is to collect photo-generated carriers and conduct them to an external circuit. Traditional solar cells usually adopt designs such as 2BB (2 main grids), 3BB, and 5BB. With the development of technology, multi-main grid (MBB, such as 12BB and 16BB) has gradually become the mainstream. However, the existence of the main grid still blocks part of the incident light and affects the cell efficiency. In order to further reduce the shading loss and improve the cell performance, the 0BB (Zero Busbar) technology without a main grid has emerged. This technology completely eliminates the main grid and only retains the fine grid lines, thus achieving a higher photo-generated conversion efficiency and a lower material cost.

[0029] Currently, there are mainly three technical routes for the 0BB (Zero Busbar) technology: dispensing / printing glue, laminating film, and high-temperature welding + dispensing. Among them, for dispensing / printing glue, glue dots are first dispensed or printed onto the cell, and then the solder tape is placed, and the solder tape forms good contact with the cell through the glue dots. For the laminating film route, after the solder tape is laid on the cell, a layer of carrier film is laminated on the solder tape, and the carrier film is melted to fix the solder tape on the cell. For the high-temperature welding + dispensing route, the infrared welding method is adopted, and glue is dispensed / printed above the welding wire after welding to improve the bonding force between the solder tape and the cell through the glue dots.

[0030] As introduced in the background art, there is a technical problem that the production rhythm of the back-contact battery module with good connection of the solder tape in the prior art is slow. To solve the above technical problem, the present application proposes a preparation method of a back-contact battery module and a back-contact battery module. Among them, in the preparation method of the back-contact battery module of the present application, first, a carrier film is provided. Then, solder tapes are respectively arranged in a plurality of predetermined areas on the carrier film, realizing one-time film covering or integral film covering of the solder tapes of the back-contact battery module. Thus, compared with the film covering process in the prior art, the preparation method of the present application greatly improves the film covering efficiency. Moreover, after the solder tapes are arranged on the carrier film, the present application performs a first heat treatment on the carrier film. The heat treatment can soften the carrier film and pre-fix the solder tapes laid on the carrier film, thereby improving the problem that the solder tapes will shift during the preparation of the back-contact battery module. Among them, the above-mentioned plurality of predetermined areas correspond one by one to a plurality of back-contact battery cells in the back-contact battery module. After that, back-contact battery cells are arranged on the solder tapes in each of the above-mentioned predetermined areas, and a second heat treatment is performed on the carrier film. As described above, when the solder tapes have been arranged in all the plurality of predetermined areas of the carrier film, the back-contact battery cells and the solder tapes on the carrier film can directly achieve electrical connection under the conditions of the above-mentioned second heat treatment without welding. Thus, compared with the prior art, the present application omits the step of high-temperature welding, further significantly improving the production efficiency of the back-contact battery module. Moreover, the softening and melting of the carrier film can tightly wrap and bond the connection between the solder tapes and the back-contact battery cells, thereby further improving the electrical connection stability and reliability between the solder tapes and the back-contact battery cells. In addition, after the back-contact battery cells are placed on the solder tapes, the present application also raises the temperature based on the temperature of the first heat treatment and performs the second heat treatment on the carrier film at the raised temperature, enabling deep bonding between the carrier film, the solder tapes and the back-contact battery cells, and enabling the integral structure of the solder tapes and the carrier film to be tightly combined with the battery cells, thereby further enhancing the mechanical strength between the solder tapes and the back-contact battery cells and improving the production yield and overall quality of the back-contact battery module. In summary, compared with the conventional film covering process, dispensing / printing process, and high-temperature welding + dispensing process in the prior art, the present application significantly improves the production efficiency of the back-contact battery module and the welding quality problem between the solder tapes and the back-contact battery cells in the back-contact battery module, thereby solving the technical problem of slow production efficiency of the back-contact battery module in the prior art.

[0031] Exemplary embodiments of the method for preparing a back-contact battery assembly provided according to the present application will be described in more detail below. However, these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concept of these exemplary embodiments to those of ordinary skill in the art.

[0032] Figure 1 FIG. is a flowchart of a method for preparing a back-contact battery assembly provided by an embodiment of the present application. Figure 2 FIG. is a schematic process diagram of setting solder tapes on a carrier film and setting back-contact battery cells on the solder tapes in a method for preparing a back-contact battery assembly provided by an embodiment of the present application. As Figure 1 and Figure 2 shown, a method for preparing a back-contact battery assembly provided by the present application includes:

[0033] S1, providing a carrier film (corresponding to Figure 2 carrier film laying in

[0034] The carrier film (carrier film) provided in the present application may be a film layer that has been laid on a certain plane. For example, the above-mentioned certain plane is the plane of the battery cell series connection platform, so that the provided carrier film is the carrier film that has been laid on the battery cell series connection platform.

[0035] Specifically, the carrier film may be a polymer film, and the polymer film has good thermoplasticity (variability and curing at a specific temperature).

[0036] Optionally, the above carrier film is a polymer film of thermoplastic polyolefins.

[0037] Exemplarily, the above thermoplastic polyolefins include ethylene-octene copolymer (POE), modified polypropylene (TPO), or ethylene-vinyl acetate copolymer (EVA).

[0038] Optionally, in order to improve the problem of high shrinkage rate of the carrier film during heat treatment, the polymer film of thermoplastic polyolefins in the present application further contains polyethylene (PE) and / or polypropylene (PP). Specifically, the crystalline regions of PP / PE may limit the movement of EVA segments, thereby reducing the thermal shrinkage rate of EVA. Specifically, the shrinkage rate of the carrier film of the present application in the first direction may be 0.5-1%, and the shrinkage rate in the second direction may be 0, where the first direction is perpendicular to the second direction.

[0039] S2, respectively setting solder tapes in a plurality of predetermined regions on the carrier film (corresponding to Figure 2(the laying of the solder tape in it), and perform the first heat treatment on the carrier film, and a plurality of predetermined areas are sequentially adjacently distributed along the first direction;

[0040] In this application, the formation of a plurality of predetermined areas on the carrier film is preset according to the design specifications of the back-contact battery assembly. For example, after determining the connection positions and layouts of the solder tapes and the back-contact battery wafers according to the design specifications of the back-contact battery assembly, mark the predetermined areas on the carrier film, so as to divide the carrier film into a plurality of predetermined areas. It can be understood that each predetermined area guides the subsequent laying of the solder tape, so that the solder tape can be accurately laid on the marked predetermined area.

[0041] Specifically, the first direction can be parallel to the film layer surface of the carrier film.

[0042] Specifically, the solder tape can be a conductive connection material that connects a plurality of back-contact battery wafers. Its main function is to establish a current path between the plurality of back-contact battery wafers, so that the current generated by each back-contact battery wafer can be smoothly conducted through the solder tape and finally converge to the output end of the back-contact battery assembly.

[0043] Generally, the solder tape is supported by a metal material and coated with solder on the surface to facilitate melting and solidification during the welding process. Among them, the solder tape can be a tin-plated copper solder tape, a silver-based solder tape or an aluminum-based solder tape.

[0044] In this application, when using the carrier film to fix the solder tape, by respectively arranging the solder tapes in a plurality of predetermined areas on the carrier film, the one-time laying of all the solder tapes of the back-contact battery assembly is realized, thereby realizing the integrated film covering of the solder tapes of the back-contact battery assembly, thus greatly improving the production efficiency of the back-contact battery assembly.

[0045] Moreover, in this application, when heating the carrier film laid with the solder tape (the first heat treatment), by utilizing the thermoplasticity of the carrier film, the carrier film is deformed and softened during the heating process, so that the carrier film has a certain adhesiveness, thereby bonding the solder tape laid (arranged) on the carrier film to the carrier film through the carrier film to form an integrated carrier film and solder tape.

[0046] It should be noted that the first heat treatment of this application can be a low-temperature treatment, that is, during the first heating process, the solder tape (including the metal material for support and the solder coated on the surface of the metal material) will not melt.

[0047] In the above steps, when the provided carrier film is laid on the battery wafer series connection platform, the first heat treatment of the carrier film can be realized by heating the battery wafer series connection platform.

[0048] In some embodiments, after the above step S2, the peeling strength of peeling the solder tape from the carrier film can be greater than 1 N.

[0049] S3. Set back-contact solar cells on the solder tapes in each predetermined area (corresponding to the cell laying in Figure 2 ), and perform a second heat treatment on the carrier film. The temperature of the second heat treatment is higher than that of the first heat treatment. The multiple predetermined areas correspond to the multiple back-contact solar cells one by one.

[0050] A back-contact solar cell is a high-efficiency solar cell with both positive and negative electrodes arranged on the back of the cell. Since the front of the cell is not blocked by grid lines, the photoelectric conversion efficiency is improved compared with a conventional solar cell with positive and negative electrodes arranged on the front and back of the cell respectively.

[0051] Since the solder tapes of the present application are disposed in multiple predetermined areas of the carrier film at one time, the setting order of the solder tapes and the back-contact solar cells does not need to be considered during the process of setting multiple back-contact solar cells on the solder tapes, simplifying the connection process of the solder tapes and the back-contact battery assembly. In some embodiments, the setting method of setting back-contact solar cells on the solder tapes in each predetermined area may be: simultaneously laying multiple back-contact solar cells on the solder tapes in the multiple predetermined areas one by one; or, laying multiple back-contact solar cells on the solder tapes in the multiple predetermined areas in series connection order one by one. Finally, back-contact solar cells are set on the solder tapes in each predetermined area.

[0052] After that, the present application performs a second heat treatment on the carrier film so that the carrier film is deformed and softened again during the second heat treatment to further increase the fluidity of the carrier film and improve the adhesion of the carrier film, thereby bonding the back-contact solar cells and the solder tapes into an integral structure.

[0053] In the above embodiment, the first heat treatment is a pre-heat treatment, the purpose of which is to soften the surface of the carrier film so that it can better fit the solder tapes. This temperature is sufficient to soften the carrier film and fix the solder tapes, thereby improving the offset phenomenon of the solder tapes. Furthermore, during the second heat treatment, by further increasing the temperature of the first heat treatment to the temperature of the second heat treatment, the carrier film can be softened and flowed more thoroughly to better fill the gaps between the solder tapes and the back-contact solar cells and between the solder tapes and the carrier film, thereby realizing the tight connection of the carrier film, the solder tapes and the back-contact solar cells. In addition, at a higher temperature, the carrier film can have a deeper intermolecular interaction with the contact surface. Therefore, the increase in the temperature of the second heat treatment also helps to enhance the adhesion between the carrier film and the solder tapes and the back-contact solar cells, and can significantly improve the long-term stability and reliability of the back-contact battery assembly.

[0054] It should be noted that the second heating treatment of this application can be a low-temperature treatment, that is, during the second heating process, the solder tape (including the metal material for support and the solder coated on the surface of the metal material) does not melt.

[0055] In the above steps, when the provided carrier film is laid on the battery string connection platform, the second heating treatment of the carrier film can be achieved by heating the battery string connection platform.

[0056] In some embodiments, after the above step S3, the peeling strength of the back contact solar cell from the carrier film can be greater than 5 N.

[0057] Optionally, in order to further improve the problem of the solder tape laid on the carrier film shifting, after the solder tape is respectively arranged in a plurality of predetermined areas on the carrier film and before the first heating treatment of the carrier film, the preparation method of the above back contact battery assembly further includes: fixing the solder tape by using a solder tape pressing device. It can be understood that the solder tape pressing device is a pressing mechanism that presses the solder tape onto the carrier film before the first heating treatment. By applying a certain pressure to the solder tape through the solder tape pressing device in this application, the contact between the solder tape and the surface of the carrier film can be increased, the mechanical stability of the solder tape fixedly connected to the predetermined area of the carrier film is improved, and the problem of the solder tape shifting caused by the softening and deformation of the carrier film during the first heating treatment is improved, thereby enhancing the reliability of the tight combination of the carrier film, the solder tape and the back contact solar cell.

[0058] Further, in order to form a gapless contact between the solder tape and the carrier film during the process of fixing the solder tape, the step of fixing the solder tape by using a solder tape pressing device can include: placing the solder tape pressing device on the solder tape; applying pressure to the solder tape pressing device until the solder tape fits the carrier film. It can be understood that by applying pressure to the solder tape pressing device placed on the solder tape, the problem of there being small gaps between the solder tape and the carrier film can be improved, which helps to achieve a seamless connection between the solder tape and the carrier film, thereby further improving the mechanical stability of the solder tape fixedly connected to the predetermined area of the carrier film, further improving the problem of the solder tape shifting during the first heating treatment, and thus further enhancing the reliability of the tight combination of the carrier film, the solder tape and the back contact solar cell.

[0059] The solder ribbon pressing device can be a pin array pressure tool, which consists of dozens to hundreds of metal pins (such as tungsten steel pins or nickel-plated copper pins). Among them, the tips of the pins can be elastic to adapt to uneven surfaces. Specifically, after the solder ribbon is precisely laid in the predetermined area of the carrier film, the pin array can descend onto the solder ribbon to make the pins contact the solder ribbon. Then, the overall downward pressure of the pin array pressure tool can be controlled by the force application side, so that the solder ribbon is fixed on the carrier film. During the above downward pressure process, multiple pins can evenly distribute the pressure, thereby improving the contact quality when the solder ribbon is in close contact with the carrier film.

[0060] Similarly, in order to prevent and improve the problem of the offset of the back contact solar cell laid on the solder ribbon, in some embodiments, after the back contact solar cell is set on the solder ribbon in each predetermined area and before the second heat treatment of the carrier film, the preparation method of the back contact solar cell assembly further includes: using the solar cell pressing device to fix the back contact solar cell.

[0061] Specifically, by applying a certain pressure to the back contact solar cell through the solar cell pressing device in this application, the contact strength between the back contact solar cell and the solder ribbon in the predetermined area of the carrier film can be increased, the mechanical stability of the fixed connection of the back contact solar cell on the solder ribbon is improved, and the problem of the offset of the contact connection between the solder ribbon and the back contact solar cell during the second heat treatment is improved. Thus, the reliability of the tight combination of the carrier film, the solder ribbon, and the back contact solar cell is further enhanced.

[0062] Furthermore, in order to form a gapless contact between the back contact solar cell and the solder ribbon in the predetermined area of the carrier film during the process of fixing the back contact solar cell, using the solar cell pressing device to fix the back contact solar cell includes: placing the solar cell pressing device on the back contact solar cell; applying pressure to the solar cell pressing device until the back contact solar cell fits with the solder ribbon. It can be understood that by applying pressure to the solar cell pressing device placed on the back contact solar cell, the problem of the existence of tiny gaps between the back contact solar cell and the solder ribbon can be improved, which helps to achieve a seamless connection between the back contact solar cell and the solder ribbon. Thus, the mechanical stability of the fixed connection of the back contact solar cell on the solder ribbon is further improved, and the problem of the offset of the contact connection between the solder ribbon and the back contact solar cell during the second heat treatment is further improved. Therefore, the reliability of the tight combination of the carrier film, the solder ribbon, and the back contact solar cell is further enhanced.

[0063] Among them, the cell pressing device can be a block pressing mechanism. It can be understood that the block pressing mechanism can better act on the back-contact cell, so that during the downward pressing process, the pressure distribution acting on the back-contact cell is more uniform, thereby improving the connection quality when the back-contact cell is in close contact with the solder strip.

[0064] In some alternative embodiments, the temperature of the first heat treatment is 80-90 °C, and the heating time of the first heat treatment is 1-2 s.

[0065] In the above embodiments, by setting the temperature of the first heat treatment at 80 °C or above and the time at 1 s or above, it can better ensure that the carrier film exhibits good adhesion during the first heat treatment, ensuring that the solder strip and the carrier film form a highly integrated structure, thereby further significantly enhancing the peel strength between the solder strip and the carrier film, making the integrated solder strip and carrier film more firm and not easily separated; by setting the temperature of the first heat treatment at 90 °C or below and the time at 2 s or below, it can better ensure that the carrier film exhibits good fluidity during the first heat treatment, ensuring that the carrier film can diffuse better, thereby significantly improving the tightness of the connection between the carrier film and the solder strip.

[0066] In some alternative embodiments, the temperature of the second heat treatment is 120-130 °C, and the heating time of the second heat treatment is 1-3 s.

[0067] In the above embodiments, by setting the temperature of the second heat treatment at 120 °C or above and the time at 1 s or above, it can better ensure that the carrier film exhibits stronger adhesion during the second heat treatment, ensuring that the carrier film, the solder strip and the back-contact cell form a highly integrated structure, thereby further significantly enhancing the peel strength between the back-contact cell and the solder strip and the carrier film, making the integrated carrier film, solder strip and back-contact cell more firm and inseparable; by setting the temperature of the second heat treatment at 130 °C or below and the time at 3 s or below, it can better ensure that the carrier film exhibits good fluidity during the second heat treatment, better ensuring the diffusion of the carrier film, so that after the solder strip and the back-contact cell are tightly connected, they can be wrapped and bonded, significantly improving the tightness of the connection between the carrier film, the solder strip and the back-contact cell.

[0068] Based on the above embodiments, a kind of as Figure 3The preparation method of the specific back-contact battery assembly shown. The preparation method includes: laying a carrier film (supporting film); then laying solder tapes in a plurality of predetermined areas of the carrier film (solder tape laying), and preheating the carrier film with the solder tapes laid thereon, the temperature of the preheating is set to 80 °C. Among them, after the solder tape laying and before the preheating, an operation of tooling to press the solder tape is performed on the solder tape on the carrier film; then, laying the back-contact battery cells on the solder tapes on the carrier film (battery laying), and reheating the carrier film with the back-contact battery cells laid thereon, the temperature of the reheating is set to 120 °C. Among them, after the back-contact battery cells are laid and before the carrier film is reheated, an operation of tooling to press the battery is performed on the back-contact battery cells on the carrier film.

[0069] In some embodiments, in order to better ensure that the carrier film can completely cover all the solder tapes on a plurality of back-contact battery cells of the back-contact battery assembly in the first direction, when the plurality of back-contact battery cells are arranged side by side in the first direction, the length of the carrier film in the first direction is greater than or equal to the total length of the plurality of back-contact battery cells in the first direction. Based on this, even if the carrier film shrinks in the first direction, since the length of the carrier film in the first direction is greater than or equal to the total length of the plurality of back-contact battery cells in the first direction, and the shrinkage rate of the carrier film itself in the first direction is small, it can still completely cover all the solder tapes on a plurality of back-contact battery cells of the back-contact battery assembly in the first direction after shrinking, thus further ensuring the reliability of the tight combination between the carrier film, the solder tape and the back-contact battery cells.

[0070] In addition, in some embodiments, in order to further simplify the series connection between two adjacent back-contact batteries in the first direction of the back-contact battery assembly, each back-contact battery cell is in contact connection with at least two solder tapes arranged at intervals; in the first direction, each back-contact battery cell is connected to the previous back-contact battery cell through one of the solder tapes and connected to the next back-contact battery cell through another solder tape. Based on this, the positive electrode of each back-contact battery cell can be electrically connected to the negative electrode of the previous back-contact battery cell through the solder tape, simplifying the process steps of the traditional series connection that requires additional operations or adjustment of the solder tape position to realize the connection of the back-contact battery cells, thereby further improving the production efficiency of the back-contact battery assembly on the basis of realizing the series connection of a plurality of back-contact battery assemblies in the back-contact battery assembly.

[0071] According to another aspect of the present application, the present application further provides a back-contact battery assembly, and the back-contact battery assembly is prepared by using any one of the preparation methods of the back-contact battery assembly as described above.

[0072] Further, the back-contact battery assembly may further include glass, encapsulant film, and a backsheet. The encapsulant film includes a front encapsulant film and a back encapsulant film. A plurality of serially-connected back-contact cells in the back-contact battery assembly are located between the front encapsulant film and the back encapsulant film. The front encapsulant film is located between the glass and the plurality of serially-connected back-contact cells, and the back encapsulant film is located between the plurality of serially-connected back-contact cells and the backsheet.

[0073] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0074] In the method for manufacturing the back-contact battery assembly of the present application, first, a carrier film is provided. Then, welding tapes are respectively disposed in a plurality of predetermined regions on the carrier film, realizing one-time film covering or integral film covering of the welding tapes of the back-contact battery assembly. Thus, compared with the film covering process in the prior art, the manufacturing method of the present application greatly improves the film covering efficiency. Moreover, after the welding tapes are disposed on the carrier film, the carrier film is subjected to a first heat treatment. The heat treatment can soften the carrier film and pre-fix the welding tapes laid on the carrier film, thereby improving the problem that the welding tapes may shift during the manufacturing process of the back-contact battery assembly. Among them, the above-mentioned plurality of predetermined regions correspond one-to-one with the plurality of back-contact cells in the back-contact battery assembly. After that, back-contact cells are disposed on the welding tapes in each of the above-mentioned predetermined regions, and the carrier film is subjected to a second heat treatment. As described above, when the welding tapes have been disposed in all the plurality of predetermined regions of the carrier film, the back-contact cells and the welding tapes on the carrier film can directly achieve electrical connection under the conditions of the above-mentioned second heat treatment without the need for welding. Thus, compared with the prior art, the present application omits the step of high-temperature welding, further significantly improving the production efficiency of the back-contact battery assembly. Moreover, the softening and melting of the carrier film can tightly wrap and bond the connection between the welding tapes and the back-contact cells, thereby further improving the electrical connection stability and reliability between the welding tapes and the back-contact cells. In addition, after the back-contact cells are placed on the welding tapes, the present application further raises the temperature based on the temperature of the first heat treatment and uses the raised temperature to perform the second heat treatment on the carrier film, enabling deep bonding between the carrier film, the welding tapes, and the back-contact cells, and enabling the integral structure of the welding tapes and the carrier film to be tightly combined with the cells, thereby further enhancing the mechanical strength between the welding tapes and the back-contact cells and improving the production yield and overall quality of the back-contact battery assembly. In summary, compared with the conventional film covering process, dispensing / printing process, and high-temperature welding + dispensing process in the prior art, the present application significantly improves the production efficiency of the back-contact battery assembly and the welding quality problem between the welding tapes and the back-contact cells in the back-contact battery assembly, thereby solving the technical problem of slow production efficiency of the back-contact battery assembly in the prior art.

[0075] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a back-contact battery component, characterized in that The back-contact battery assembly includes a plurality of back-contact battery cells, and the preparation method of the back-contact battery assembly includes: Providing a carrier film; Disposing solder tapes in a plurality of predetermined areas on the carrier film respectively, and performing a first heat treatment on the carrier film. The plurality of predetermined areas are adjacently distributed in sequence along a first direction; Disposing back-contact battery cells on the solder tapes in each of the predetermined areas, and performing a second heat treatment on the carrier film. The temperature of the second heat treatment is higher than that of the first heat treatment. The plurality of predetermined areas correspond to the plurality of back-contact battery cells one by one.

2. The preparation method of the back contact battery component according to claim 1, characterized in that, After disposing the solder tapes in the plurality of predetermined areas on the carrier film respectively and before performing the first heat treatment on the carrier film, the preparation method of the back-contact battery assembly further includes: fixing the solder tapes by using a solder tape pressing device.

3. The preparation method of the back-contact battery component according to claim 2, wherein Fixing the solder tapes by using a solder tape pressing device includes: Placing the solder tape pressing device on the solder tapes; Applying pressure to the solder tape pressing device until the solder tapes are attached to the carrier film.

4. The preparation method of the back-contact battery component according to claim 1, wherein, After disposing the back-contact battery cells on the solder tapes in each of the predetermined areas and before performing the second heat treatment on the carrier film, the preparation method of the back-contact battery assembly further includes: fixing the back-contact battery cells by using a battery cell pressing device.

5. The preparation method of the back-contact battery component according to claim 4, wherein, Fixing the back-contact battery cells by using a battery cell pressing device includes: Placing the battery cell pressing device on the back-contact battery cells; Applying pressure to the battery cell pressing device until the back-contact battery cells are attached to the solder tapes.

6. The preparation method of the back-contact battery component according to claim 1, wherein The temperature of the first heat treatment is 80-90 °C, and the heating time of the first heat treatment is 1-2 s.

7. The preparation method of the back contact battery component according to claim 1, wherein, The temperature of the second heat treatment is 120-130 °C, and the heating time of the second heat treatment is 1-3 s.

8. The preparation method of the back-contact battery component according to claim 1, wherein, When the plurality of back-contact battery cells are arranged side by side along the first direction, the length of the carrier film in the first direction is greater than or equal to the total length of the plurality of back-contact battery cells in the first direction.

9. The preparation method of the back-contact battery assembly according to any one of claims 1 to 8, characterized in that Each back-contact battery cell is in contact connection with at least two solder tapes arranged at intervals; In the first direction, each back-contact battery cell is connected to the previous back-contact battery cell through one of the solder tapes and connected to the next back-contact battery cell through the other solder tape.

10. A back-contact battery component, characterized in that, The back-contact battery assembly is prepared by using the preparation method of the back-contact battery assembly according to any one of claims 1 to 9.

Images