Battery module integrated busbar
By integrating the FFC main board with the connecting terminals into one piece, the problem of fuse breakage caused by welding stress in traditional battery module integrated busbars is solved, achieving high reliability and low cost battery module connection, and improving product stability and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JINGSHI ELECTRONICS TECH CO LTD SUZHOU
- Filing Date
- 2025-07-03
- Publication Date
- 2026-06-16
AI Technical Summary
Traditional battery module integrated busbars suffer from fuse breakage due to dissimilar metal welding and welding stress during the welding process, resulting in high cost, low reliability, and complex production issues.
The design adopts an integrated molding of the FFC main board and connecting terminals, including a chamfered structure and longitudinal connecting pieces, to disperse the welding stress path. It also achieves efficient dissimilar metal connection through soldering and ultrasonic/laser welding. Combined with insulating film protection and thermal expansion compensation structure, it improves mechanical strength and reliability.
It effectively reduces the risk of fuse breakage caused by welding vibration, improves product reliability and yield, simplifies production processes, reduces costs, and enhances resistance to high-frequency vibration.
Smart Images
Figure CN224367073U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of FFC wiring harness technology, and more specifically, to a battery module integrated busbar. Background Technology
[0002] With the rapid development of the new energy vehicle industry, the battery module integrated busbar (CCS), as a key component of the power battery system, has attracted much attention regarding its reliability and production cost. Traditional CCS mainly uses flexible printed circuit boards (FPCs) prepared by etching processes as sampling harnesses, but this process has significant drawbacks:
[0003] High cost and environmental issues: The etching process consumes a large amount of chemical reagents, which not only results in high production costs but also makes waste liquid treatment difficult and causes environmental pollution.
[0004] The challenge of welding dissimilar metals: The conductive layer of the FPC is usually copper-based, while the busbar 30 (aluminum bar) of the battery module is made of aluminum. Direct copper-aluminum welding requires ultrasonic welding, but this process has extremely high requirements for the precision of the weld joints, which can easily lead to low yield and poor efficiency.
[0005] The transition scheme becomes more complicated: In order to avoid welding dissimilar metals, some schemes use nickel sheet transition connection (such as SMT + reflow soldering), but this increases the production process and material costs.
[0006] Although existing technologies, such as the FAC flexible circuit board proposed in patent CN118870651A, which replaces the etched FPC with an FFC copper-based main board and combines it with an aluminum-based FPC branch board to connect the aluminum bar, initially solving the problems of etching contamination and dissimilar metal welding, the fuse structure on its branch board still faces serious challenges: the fuse is prone to breakage during welding: when the aluminum bar is welded to the branch board (especially ultrasonic / laser welding), mechanical stress is transmitted along the rigid path to the weak area of the fuse, leading to vibration failure. Stress concentration without relief design: traditional fuses are directly connected to the solder joint without a stress buffer structure, making it difficult to adapt to high vibration conditions. Utility Model Content
[0007] In view of this, there is an urgent need for a new battery module integrated busbar structure that combines low cost, high reliability and fuse protection, so as to fundamentally solve the problem of fuse breakage caused by welding stress.
[0008] A battery module integrated busbar includes: an FFC main board 10, multiple connection terminals 20, and a busbar 30. The FFC main board 10 includes upper and lower insulating layers and multiple spaced flat conductors 12 sandwiched between the two insulating layers. At least one side of the insulating layer has multiple windows to expose the corresponding flat conductors 12. Each connection terminal 20 includes a first welding portion 21, a fuse portion 23, and a second welding portion 28, which are integrally formed from conductive material. The busbar 30 is configured to connect the electrodes of the battery module. The first welding portion 21 is welded to the FFC main board 10 through the corresponding window. The flat conductor 12; the second welding part 28 is welded to the busbar 30; the fuse part 23 is located between the first welding part 21 and the second welding part 28, characterized in that the fuse part 23 is connected to the second welding part 28 through a longitudinal connecting piece 26, and the longitudinal connecting piece 26 is provided with a chamfer structure 24 near the second welding part 28. Through the design of the chamfer structure 24 on the longitudinal connecting piece 26, the stress transmission path is effectively dispersed or changed during the welding process (especially ultrasonic welding), significantly reducing the mechanical stress transmitted to the fuse part 23, fundamentally solving the problem of fuse breakage caused by welding vibration in traditional integrated busbars, and improving product reliability and yield.
[0009] Furthermore, the lower extension of the chamfered structure 24 is provided with a groove 25. The groove 25 is added to the outer edge of the chamfered structure 24 to further absorb and buffer stress energy, prevent stress from concentrating at the chamfered edge, make stress release more gradual, enhance the ability to resist high-frequency vibration, and provide double protection for the fuse.
[0010] Furthermore, the fuse part 23 is connected to the first welding part 21 through another longitudinal connecting piece 26. The fuse part 23 and the first welding part 21 are connected by another longitudinal connecting piece 26 to form a symmetrical or balanced stress transmission structure, which avoids the welding stress impacting the fuse on one side, while improving the overall mechanical strength of the terminal and extending its service life.
[0011] In some embodiments, the fuse portion 23 includes a plurality of first bent portions 27. The multiple bends of the fuse portion 23 extend the current path and increase the heat capacity, allowing it to melt faster during overcurrent. At the same time, the bend structure itself can absorb some vibration energy, thus reducing the direct impact of stress on the fuse.
[0012] Furthermore, the fuse portion 23 is inclined relative to the first welding portion 21 and the second welding portion 28. The inclined fuse portion 23 forms a non-perpendicular angle with the welding direction, which forces the mechanical stress to be decomposed along the inclined surface, reduces the destructive component force acting vertically on the fuse, and further suppresses the risk of breakage.
[0013] Furthermore, the fuse portion 23 is at least partially covered by an insulating film 29, and the first solder portion 21 and the second solder portion 28 are exposed. The insulating film 29 covers the fuse body to prevent short circuits or oxidation, while the exposed first and second solder portions 28 ensure reliable electrical connections. This design balances insulation protection with ease of soldering, simplifying the manufacturing process.
[0014] Furthermore, the first welding part 21 is provided with a plurality of welding holes 22. The multi-row welding hole structure of the first welding part 21 increases the solder filling space, expands the welding contact area, significantly improves the bonding strength with the flat conductor 12, and at the same time alleviates the problem of welding thermal stress concentration.
[0015] Furthermore, the first welding part 21 is connected to the flat conductor 12 by soldering. The soldering process is compatible with the temperature-sensitive characteristics of the FFC main board 10, avoiding high temperature damage to the insulation layer. Liquid tin fills the solder hole to form a mechanical interlock, achieving a connection with high conductivity and high reliability.
[0016] Furthermore, the second welding part 28 is connected to the busbar 30 by ultrasonic welding or laser welding. Ultrasonic / laser welding achieves efficient dissimilar metal connection between the aluminum busbar 30 and the copper-based terminal, avoiding the need for traditional transition parts; the low heat input characteristics prevent the fuse from melting due to heat, ensuring functional integrity.
[0017] In some embodiments, the busbar 30 includes a second bent portion 31 for accommodating the thermal expansion of the battery module. The second bent portion 31 of the busbar 30 acts as a thermal expansion compensation structure, absorbing dimensional changes during battery charge and discharge cycles, eliminating the pulling effect of busbar deformation on the welding points, and improving long-term stability at the system level.
[0018] The beneficial effects of this utility model are as follows: This utility model proposes an integrated busbar for a battery module, comprising: an FFC main board 10, multiple connection terminals 20, and a busbar 30. The FFC main board 10 includes upper and lower insulating layers and multiple spaced flat conductors 12 sandwiched between the two insulating layers. At least one side of the insulating layer has multiple windows to expose the corresponding flat conductors 12. Each connection terminal 20 includes a first welding part 21, a fuse part 23, and a second welding part 28, which are integrally formed from conductive material. The busbar 30 is configured to connect the electrodes of the battery module. The first welding part 21 is welded through the corresponding window. The flat conductor 12 is connected to the FFC main board 10; the second welding part 28 is welded to the busbar 30; the fuse part 23 is located between the first welding part 21 and the second welding part 28, and the fuse part 23 is connected to the second welding part 28 through a longitudinal connecting piece 26. The longitudinal connecting piece 26 is provided with a chamfer structure 24 near the second welding part 28. Through the design of the chamfer structure 24 on the longitudinal connecting piece 26, the stress transmission path is effectively dispersed or changed during the welding process (especially ultrasonic welding), which significantly reduces the mechanical stress transmitted to the fuse part 23, fundamentally solving the problem of fuse breakage caused by welding vibration in traditional integrated busbars, and improving product reliability and yield. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the integrated busbar structure of the battery module in this application.
[0020] Figure 2 This is a schematic diagram of the connection terminal structure of this application.
[0021] Figure 3 This is a schematic diagram of the fuse section of this application.
[0022] Explanation of main component symbols
[0023] FFC main plate 10, flat conductor 12, connecting terminal 20, first welding part 21, welding hole 22, fuse part 23, chamfer structure 24, groove 25, longitudinal connecting piece 26, first bending part 27, second welding part 28, insulating film 29, busbar 30, second bending part 31.
[0024] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation
[0025] The following embodiments are described to aid in understanding this application. These embodiments are not, and should not be, construed in any way as limiting the scope of protection of this application.
[0026] In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as individual functional units (which may include subunits), but those skilled in the art will recognize that various components or portions thereof may be divided into individual components or may be integrated together (including integrated within a single system or component).
[0027] Furthermore, the connection between components or systems is not intended to be limited to a direct connection; on the contrary, data between these components may be modified, reformatted, or otherwise altered by intermediate components. Additionally, other or fewer connections may be used. It should also be noted that the terms "connection," "link," or "input" should be understood to include direct connections, indirect connections via one or more intermediate devices, and wireless connections.
[0028] Example 1:
[0029] like Figure 1-3As shown, a battery module integrated busbar includes: an FFC main board 10, multiple connection terminals 20, and a busbar 30. The FFC main board 10 includes upper and lower insulating layers and multiple spaced flat conductors 12 sandwiched between the two insulating layers. At least one side of the insulating layer has multiple windows to expose the corresponding flat conductors 12. Each connection terminal 20 includes a first welding part 21, a fuse part 23, and a second welding part 28, which are integrally formed from conductive material. The busbar 30 is configured to connect the electrodes of the battery module. The first welding part 21 is welded to the flat conductors 12 of the FFC main board 10 through the corresponding windows. The second welding part 28 is welded to the busbar 30. The fuse part 23 is located between the first welding part 21 and the second welding part 28, and the fuse part 23 is connected to the second welding part 28 through a longitudinal connecting piece 26. A chamfered structure 24 is provided near the second welding part 28. The chamfered structure 24 on the longitudinal connecting piece 26 effectively disperses or changes the stress transmission path during the welding process (especially ultrasonic welding), significantly reducing the mechanical stress transmitted to the fuse part 23. This fundamentally solves the problem of fuse breakage caused by welding vibration in traditional integrated busbars, improving product reliability and yield. The lower extension of the chamfered structure 24 is provided with a groove 25. The groove 25 added to the outer edge of the chamfered structure 24 further absorbs and buffers stress energy, preventing stress concentration at the chamfer edge, making stress release smoother, enhancing the ability to resist high-frequency vibration, and providing double protection for the fuse. The fuse part 23 is connected to the first welding part 21 through another longitudinal connecting piece 26. The fuse part 23 and the first welding part 21 are connected by another longitudinal connecting piece 26 to form a symmetrical or balanced stress transmission structure, avoiding unilateral impact of welding stress on the fuse, while improving the overall mechanical strength of the terminal and extending its service life.
[0030] The fuse portion 23 includes multiple first bends 27. The multiple bends in the fuse portion 23 extend the current path and increase the heat capacity, allowing for faster melting during overcurrent. Simultaneously, the bends themselves absorb some vibration energy, synergistically reducing the direct impact of stress on the fuse. The fuse portion 23 is inclined relative to the first weld portion 21 and the second weld portion 28. The inclined fuse portion 23 forms a non-perpendicular angle with the welding direction, forcing mechanical stress to decompose along the inclined surface, reducing the destructive component of the force acting perpendicularly on the fuse, and further suppressing the risk of breakage. The fuse portion 23 is at least partially covered by an insulating film 29, while the first weld portion 21 and the second weld portion 28 are exposed. The insulating film 29 covers the fuse body to prevent short circuits or oxidation, while the exposed first and second weld portions 28 ensure reliable electrical connections. This design balances insulation protection with ease of welding, simplifying the production process. The first welding part 21 has multiple welding holes 22. The multi-row welding hole structure of the first welding part 21 increases the solder filling space, expands the welding contact area, significantly improves the bonding strength with the flat conductor 12, and alleviates the problem of welding heat stress concentration. The first welding part 21 and the flat conductor 12 are connected by soldering. The soldering process is compatible with the temperature-sensitive characteristics of the FFC main board 10, avoiding high-temperature damage to the insulation layer. Liquid tin fills the welding holes to form a mechanical interlock, achieving a highly conductive and reliable connection. The second welding part 28 is connected to the busbar 30 by ultrasonic welding or laser welding. Ultrasonic / laser welding achieves efficient dissimilar metal connection between the aluminum busbar 30 and the copper-based terminal, avoiding the need for traditional transition parts. The low heat input characteristic prevents the fuse from melting due to heat, ensuring functional integrity.
[0031] The busbar 30 includes a second bent portion 31, which is used to adapt to the thermal expansion of the battery module. The second bent portion 31 of the busbar 30 acts as a thermal expansion compensation structure, absorbing the dimensional changes during battery charge and discharge cycles, eliminating the pulling of busbar deformation on the welding points, and improving long-term stability at the system level.
[0032] The beneficial effects of this utility model are as follows: This utility model proposes an integrated busbar for a battery module, comprising: an FFC main board 10, multiple connection terminals 20, and a busbar 30. The FFC main board 10 includes upper and lower insulating layers and multiple spaced flat conductors 12 sandwiched between the two insulating layers. At least one side of the insulating layer has multiple windows to expose the corresponding flat conductors 12. Each connection terminal 20 includes a first welding part 21, a fuse part 23, and a second welding part 28, which are integrally formed from conductive material. The busbar 30 is configured to connect the electrodes of the battery module. The first welding part 21 is welded through the corresponding window. The flat conductor 12 is connected to the FFC main board 10; the second welding part 28 is welded to the busbar 30; the fuse part 23 is located between the first welding part 21 and the second welding part 28, and the fuse part 23 is connected to the second welding part 28 through a longitudinal connecting piece 26. The longitudinal connecting piece 26 is provided with a chamfer structure 24 near the second welding part 28. Through the design of the chamfer structure 24 on the longitudinal connecting piece 26, the stress transmission path is effectively dispersed or changed during the welding process (especially ultrasonic welding), which significantly reduces the mechanical stress transmitted to the fuse part 23, fundamentally solving the problem of fuse breakage caused by welding vibration in traditional integrated busbars, and improving product reliability and yield.
[0033] Although this application discloses several aspects and embodiments, other aspects and embodiments will be obvious to those skilled in the art. Various modifications and improvements can be made without departing from the concept of this application, and these all fall within the scope of protection of this application. The various aspects and embodiments disclosed in this application are for illustrative purposes only and are not intended to limit this application. The actual scope of protection of this application is determined by the claims.
Claims
1. A battery module integrated busbar, comprising: The FFC main board (10), multiple connection terminals (20), and bus (30) are provided. The FFC main board (10) includes upper and lower insulating layers and multiple spaced flat conductors (12) sandwiched between the two insulating layers. At least one insulating layer has multiple windows to expose the corresponding flat conductors (12). Each connection terminal (20) includes a first solder part (21), a fuse part (23), and a second solder part (28). The first solder part (21), the fuse part (23), and the second solder part (28) are integrally formed from conductive material. The bus (30) is configured to connect the battery module. The first welding part (21) is welded to the flat conductor (12) of the FFC main plate (10) through a corresponding window; the second welding part (28) is welded to the busbar (30); the fuse part (23) is located between the first welding part (21) and the second welding part (28), characterized in that the fuse part (23) is connected to the second welding part (28) through a longitudinal connecting piece (26), and the longitudinal connecting piece (26) is provided with a chamfer structure (24) near the second welding part (28) to reduce the mechanical stress transmitted to the fuse part (23) during the welding process.
2. The battery module integrated busbar as described in claim 1, characterized in that: The lower extension of the chamfered structure (24) is provided with a groove (25).
3. The battery module integrated busbar as described in claim 1, characterized in that: The fuse part (23) is connected to the first welding part (21) via another longitudinal connecting piece (26).
4. The battery module integrated busbar as described in claim 1, characterized in that: The fuse section (23) includes a plurality of first bent portions (27).
5. The battery module integrated busbar as described in claim 1, characterized in that: The fuse part (23) is inclined relative to the first welding part (21) and the second welding part (28).
6. The battery module integrated busbar as described in claim 1, characterized in that: The fuse portion (23) is at least partially covered by an insulating film (29), and the first solder portion (21) and the second solder portion (28) are exposed.
7. The battery module integrated busbar as described in claim 1, characterized in that: The first welding part (21) is provided with a plurality of welding holes (22).
8. The battery module integrated busbar as described in claim 1, characterized in that: The first welded part (21) is connected to the flat conductor (12) by soldering.
9. The battery module integrated busbar as described in claim 1, characterized in that: The second welded part (28) is connected to the busbar (30) by ultrasonic welding or laser welding.
10. The battery module integrated busbar as described in claim 1, characterized in that: The busbar (30) includes a first bent portion (27) for accommodating the thermal expansion of the battery module.