Battery module sampling components and their preparation methods

Abstract

This invention belongs to the field of lithium-ion battery technology, specifically relating to a battery module sampling component, including a blister tray, an aluminum busbar, and an FPC; both the aluminum busbar and the FPC are mounted on the blister tray; the FPC is directly welded to the aluminum busbar, and no nickel strip adapter is provided between the FPC and the aluminum busbar. This invention eliminates the nickel strip adapter connecting the aluminum busbar and the FPC in traditional solutions and uses a reflow soldering process to achieve a direct connection between the aluminum busbar and the FPC. Simultaneously, the temperature sensing element and connector on the aluminum busbar and the FPC are fixed in the same reflow soldering process, significantly simplifying the number of components and the manufacturing process of the CCS, eliminating the laser welding process in conventional solutions, thereby effectively improving the production efficiency of the CCS and reducing raw material and manufacturing costs.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a battery module sampling component and its preparation method. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage systems, the safety and reliability of battery modules, as their core components, are receiving increasing attention. Within the battery module, the sampling component (CCS, Cell Contacting System) is used to collect voltage and temperature signals from the battery cells, and is a key component enabling the Battery Management System (BMS) to monitor and manage the battery's state.

[0003] Currently, such as Figure 1 and Figure 2 As shown, most mature battery module sampling solutions adopt a structure combining flexible printed circuit boards (FPCs), nickel strips, and aluminum busbars. The typical process flow is as follows: First, the temperature sensor (NTC), connectors, and nickel strips are mounted onto the FPC using surface mount technology (SMT), and then fixed using reflow soldering. Next, the nickel strips on the FPC are connected to the aluminum busbars using laser welding. Finally, the assembled FPC and aluminum busbars are fixed to a blister pack using a hot-riveting process to form a complete CCS assembly.

[0004] However, this solution requires the use of nickel sheets as the adapter between the FPC and the aluminum busbar, resulting in a complex structure, involving two welding processes: reflow soldering and laser welding. The process is cumbersome and the raw material cost is high. In addition, due to the large number of connection points, it not only affects production efficiency but also has a relatively high failure rate. Summary of the Invention

[0005] The purpose of this invention is to provide a battery module sampling component and its preparation method, which simplifies the structure and manufacturing process of CCS while ensuring sampling accuracy, thereby reducing costs and defect rates.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a battery module sampling assembly, including a blister tray, an aluminum busbar, and an FPC; both the aluminum busbar and the FPC are mounted on the blister tray; the FPC is directly welded to the aluminum busbar, and no nickel strip adapter is provided between the FPC and the aluminum busbar.

[0007] Preferably, the FPC and the aluminum busbar are fixedly connected by a reflow soldering process, and the temperature sensing element and connector on the FPC are simultaneously fixed to the FPC by the aluminum busbar through the same reflow soldering process.

[0008] Preferably, the FPC is provided with pads for connecting the aluminum busbar, the pads are provided with solder paste, and the aluminum busbar is soldered to the pads of the FPC through the solder paste; the size of the pads is greater than or equal to 10mm × 10mm.

[0009] Preferably, the shape of the solder pad is a grid shape or other geometric shape that facilitates venting during the soldering process.

[0010] Preferably, the FPC includes an FPC body, a connector, and a temperature sensing element. The FPC body is provided with a voltage sampling line and a temperature sampling line. The voltage sampling line is connected to the pads connected to the aluminum busbar and the corresponding pins of the connector. The temperature sampling line is connected to the pads of the temperature sensing element and the corresponding pins of the connector.

[0011] Preferably, a nickel plating layer is provided at the welding position between the aluminum busbar and the FPC, and the thickness of the nickel plating layer is 3~10μm.

[0012] Preferably, the FPC is an aluminum foil FPC.

[0013] Preferably, the FPC is fixedly connected to the blister tray by hot riveting, and the aluminum strip is also fixedly connected to the blister tray by hot riveting.

[0014] This invention also discloses a method for preparing the aforementioned battery module sampling component, comprising the following steps: S1: Provide an FPC, which has pads for connecting aluminum busbars; S2: The temperature sensing element, connector and aluminum busbar are mounted on the corresponding pad positions of the FPC using the SMT process; S3: The temperature sensing element, connector, and aluminum busbar are welded and fixed to the FPC in one step using a reflow soldering process; S4: The welded FPC and aluminum busbar are assembled onto the blister tray using a hot riveting process to form a sampling assembly.

[0015] Preferably, after the FPC is welded to the aluminum busbar, the process further includes a step of dispensing adhesive to encapsulate the temperature sensing element.

[0016] The beneficial effects of this invention are as follows: By eliminating the nickel sheet adapter connecting the aluminum busbar and the FPC in the traditional solution, and by using a reflow soldering process to achieve a direct connection between the aluminum busbar and the FPC, the present invention simultaneously fixes the temperature sensing element and connector on the aluminum busbar and the FPC through the same reflow soldering process. This significantly simplifies the number of components and the manufacturing process of CCS, eliminates the laser welding process in the conventional solution, thereby effectively improving the production efficiency of CCS, reducing raw material costs and manufacturing costs. At the same time, due to the reduction in the number of connection points and components, the failure rate and defect rate of the product are also reduced accordingly, improving the reliability and consistency of the battery module sampling components. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a battery module sampling component in the prior art; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the structure of the battery module sampling component provided in an embodiment of the present invention; Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 This is a perspective view of the blister pack provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the aluminum busbar provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the FPC provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the connector and temperature sensing element installed on the FPC body according to an embodiment of the present invention.

[0018] In the diagram: 1-blister tray; 2-aluminum busbar; 2-1-nickel plating layer; 3-FPC; 3-1-connector; 3-2-temperature sensing element; 3-3-FPC body; 3-4-soldering pad. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixed connection," and "fixed connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1

[0022] like Figures 3-8 As shown, this embodiment provides a battery module sampling assembly, including a blister tray 1, an aluminum busbar 2, and an FPC 3. Both the aluminum busbar 2 and the FPC 3 are mounted on the blister tray 1; the FPC 3 is directly welded to the aluminum busbar 2, and no nickel strip adapter is provided between the FPC 3 and the aluminum busbar 2.

[0023] Specifically, the vacuum-formed support 1, serving as the main body supporting the aluminum busbar 2 and FPC 3, is manufactured using a vacuum forming process and has mounting slots and positioning structures that match the aluminum busbar 2 and FPC 3. The aluminum busbar 2, serving as the main body carrying the overcurrent of the module, is typically made of aluminum, possessing good electrical and thermal conductivity. The FPC 3, serving as the main body for collecting the potential of the battery cells corresponding to the aluminum busbar of the acquisition component 2, incorporates a voltage sampling circuit and a temperature sampling circuit.

[0024] The FPC 3 and the aluminum busbar 2 are fixedly connected by a reflow soldering process, and the temperature sensing element 3-2 and connector 3-1 on the FPC 3 are simultaneously fixed to the aluminum busbar 2 by the same reflow soldering process. This synchronous soldering method eliminates the two-step soldering process required in conventional solutions, which involves first soldering the temperature sensing element and connector to the FPC and then connecting the nickel sheet to the aluminum busbar by laser soldering. This simplifies the production process and improves production efficiency.

[0025] like Figure 7 and Figure 8 As shown, the FPC 3 includes a connector 3-1, a temperature sensing element 3-2, and an FPC body 3-3. The FPC body 3-3 is provided with a voltage sampling line and a temperature sampling line. The voltage sampling line is connected to the pad 3-4 connected to the aluminum busbar 2 and the corresponding pin of the connector 3-1. The temperature sampling line is connected to the pad of the temperature sensing element 3-2 and the corresponding pin of the connector 3-1.

[0026] Specifically, the FPC body 3-3 incorporates voltage and temperature sampling circuits through etching. The temperature sampling circuit connects to the pads of the temperature sensing element NTC and the corresponding pin pads of the connector; the voltage sampling circuit connects to the aluminum busbar pads and the corresponding pin pads of the connector.

[0027] To achieve direct welding between FPC 3 and aluminum busbar 2, this embodiment features an optimized structural design: The FPC 3 is provided with pads 3-4 for connecting the aluminum busbar 2. The pads 3-4 are coated with solder paste, and the aluminum busbar 2 is soldered to the pads 3-4 of the FPC 3 through the solder paste. Preferably, the size of the pads 3-4 is greater than or equal to 10mm × 10mm to ensure sufficient soldering area and connection strength.

[0028] To further optimize welding quality, the shape of the solder pads 3-4 can be designed as a grid pattern. This shape facilitates gas venting during welding, reduces porosity defects, and improves welding reliability. In other embodiments, the shape of the solder pads can also be adjusted to other geometric shapes that facilitate gas venting, depending on design requirements.

[0029] A nickel plating layer 2-1, with a thickness of 3~10μm, is provided at the welding position between the aluminum busbar 2 and the FPC 3. Nickel plating improves the solderability of the aluminum busbar surface, ensures good wetting and bonding between the aluminum busbar and the solder paste on the FPC, and guarantees welding quality.

[0030] As another implementation, the FPC 3 can be an aluminum foil FPC, that is, the substrate or pad area of ​​the FPC is made of aluminum foil, which is beneficial for welding with the aluminum busbar 2 and avoids reliability problems caused by welding dissimilar materials.

[0031] The FPC 3 is fixedly connected to the blister tray 1 by heat riveting, and the aluminum strip 2 is also fixedly connected to the blister tray 1 by heat riveting. The heat riveting process involves heating and softening the heat riveting posts on the blister tray and then flattening them, thereby fixing the FPC and aluminum strip to the tray. This connection method is simple and reliable, requiring no additional fasteners. Example 2

[0032] This embodiment provides a method for preparing a battery module sampling component as described in Embodiment 1, including the following steps: Step S1: Provide an FPC 3, which has pads 3-4 for connecting the aluminum busbar 2. The FPC 3 is formed with built-in voltage and temperature sampling lines using an etching process. The position and size of the pads are preset according to design requirements. Preferably, the pad size is greater than or equal to 10mm × 10mm, and the pad shape can be designed as a grid.

[0033] Step S2: Apply solder paste to pads 3-4 of FPC 3. The solder paste can be applied using stencil printing or dispensing. The thickness and distribution of the solder paste must be controlled to ensure uniformity to guarantee soldering quality.

[0034] Step S3: The temperature sensing element 3-2, connector 3-1, and aluminum busbar 2 are mounted on the corresponding pad positions of the FPC 3 using SMT technology. The area where the aluminum busbar 2 is soldered to the FPC 3 is pre-plated with nickel to form a nickel plating layer 2-1. The thickness of the nickel plating layer 2-1 is controlled between 3 and 10 μm to improve soldering performance.

[0035] Step S4: Using a reflow soldering process, the temperature sensing element 3-2, connector 3-1, and aluminum busbar 2 are soldered and fixed to the FPC 3 in a single operation. The temperature profile for reflow soldering needs to be optimized based on the characteristics of the solder paste and the heat resistance of the components to ensure that all solder joints are fully melted and form a good intermetallic compound bonding layer. This step enables direct soldering of the aluminum busbar to the FPC without the need for additional laser soldering, simplifying the process flow.

[0036] Step S5: Assemble the welded FPC 3 and aluminum strip 2 onto the blister tray 1 using a hot riveting process to form a sampling assembly. Specifically, place the FPC 3 and aluminum strip 2 at their corresponding installation positions on the blister tray 1, and use a hot riveting machine to heat and soften the hot riveting posts on the blister tray and flatten them, thereby fixing the FPC and aluminum strip onto the tray.

[0037] Step S6: Apply encapsulating adhesive to the temperature sensing element 3-2. Apply encapsulating adhesive around the temperature sensing element; after curing, it provides protection and fixation, improving the product's reliability and durability.

[0038] To verify the technical effect of the present invention, a control group was set up, using a conventional CCS solution of FPC + nickel sheet + aluminum busbar. In this solution, the FPC and the aluminum busbar need to be connected by a nickel sheet. The components on the FPC are mounted by SMT and then soldered by reflow soldering. Then, the nickel sheet and the aluminum busbar are connected by laser soldering, and finally, they are heat-riveted onto a blister tray to form a CCS assembly.

[0039] Comparative testing shows that, compared to the comparative example, the sampling component described in Embodiment 1 of this invention has fewer components (eliminating the nickel sheet), fewer welding steps (simplifying the two steps of reflow soldering and laser welding to a single reflow soldering), an increase in production efficiency of approximately 30%, and a reduction in raw material costs of approximately 15%. At the same time, due to the reduction in connection points, the product defect rate and failure rate are also reduced accordingly.

[0040] In other embodiments of the present invention, the above technical solutions can be adjusted according to specific application requirements: The pad size can be adjusted according to design requirements. For example, in applications with high current, the pad size can be increased to ensure current carrying capacity; in applications with limited space, the pad size can be reduced while ensuring soldering quality.

[0041] The thickness of the nickel plating layer on the aluminum busbar can be adjusted according to the welding process requirements. For example, when the welding temperature is high or the time is long, the plating thickness can be appropriately increased to ensure welding reliability.

[0042] Besides heat riveting, FPC can also be fixed to the blister tray using snap-fit ​​connections, adhesive bonding, or other methods, as long as reliable fixing can be achieved.

[0043] In addition to dispensing, temperature sensing elements can also be packaged using injection molding, covering film, or other methods.

[0044] In summary, the battery module sampling component and its manufacturing method provided by this invention, through optimized structural design and process flow, eliminate the nickel sheet adapter and laser welding process, simplify the number of CCS components and manufacturing process, effectively improve the manufacturing efficiency of CCS, reduce the defect rate, and have significant technological progress and practical value.

[0045] For those skilled in the art, various improvements and modifications can be made without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A battery module sampling component, characterized in that, It includes a blister tray (1), an aluminum strip (2) and an FPC (3); the aluminum strip (2) and the FPC (3) are both installed on the blister tray (1); the FPC (3) is directly welded to the aluminum strip (2), and no nickel sheet adapter is provided between the FPC (3) and the aluminum strip (2).

2. The battery module sampling component according to claim 1, characterized in that, The FPC (3) and the aluminum busbar (2) are fixedly connected by a reflow soldering process, and the temperature sensing element (3-2) and connector (3-1) on the FPC (3) and the aluminum busbar (2) are simultaneously fixed on the FPC (3) by the same reflow soldering process.

3. The battery module sampling component according to claim 1, characterized in that, The FPC (3) is provided with pads (3-4) for connecting the aluminum busbar (2). The pads (3-4) are provided with solder paste. The aluminum busbar (2) is soldered to the pads (3-4) of the FPC (3) through the solder paste. The size of the pads (3-4) is greater than or equal to 10mm × 10mm.

4. The battery module sampling component according to claim 3, characterized in that, The shape of the pads (3-4) is a grid shape or other geometric shape that facilitates venting during the welding process.

5. The battery module sampling component according to claim 4, characterized in that, The FPC (3) includes an FPC body (3-3), a connector (3-1), and a temperature sensing element (3-2). The FPC body (3-3) is provided with a voltage sampling line and a temperature sampling line. The voltage sampling line is connected to the pad (3-4) connected to the aluminum busbar (2) and the corresponding pin of the connector (3-1). The temperature sampling line is connected to the pad of the temperature sensing element (3-2) and the corresponding pin of the connector (3-1).

6. The battery module sampling component according to claim 1, characterized in that, The aluminum busbar (2) is welded to the FPC (3) with a nickel plating layer, the thickness of which is 3~10μm.

7. The battery module sampling component according to claim 1, characterized in that, The FPC (3) is an aluminum foil FPC.

8. The battery module sampling component according to claim 1, characterized in that, The FPC (3) is fixedly connected to the blister tray (1) by hot riveting, and the aluminum strip (2) is also fixedly connected to the blister tray (1) by hot riveting.

9. A method for preparing a battery module sampling component as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Provide an FPC (3) having pads (3-4) for connecting aluminum busbars (2). S2: The temperature sensing element (3-2), connector (3-1) and aluminum busbar (2) are mounted on the corresponding pad positions of the FPC (3) by SMT process; S3: The temperature sensing element (3-2), connector (3-1) and aluminum busbar (2) are welded and fixed to the FPC (3) in one go by reflow soldering process; S4: The welded FPC (3) and aluminum busbar (2) are assembled onto the blister tray (1) by hot riveting process to form a sampling assembly.

10. The preparation method according to claim 9, characterized in that, After the FPC (3) is welded to the aluminum busbar (2), the process further includes the step of dispensing and encapsulating the temperature sensing element (3-2).

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