A battery signal acquisition integrated structure based on flexible flat cable and its fabrication method

Abstract

This invention relates to the field of new energy battery technology, and in particular to a battery signal acquisition integrated structure based on a flexible flat cable and its fabrication method. The structure includes a vacuum-formed bracket, a flexible flat cable, multiple acquisition nickel plates, multiple aluminum busbars, and connectors. Each end of the acquisition nickel plate has a locking block and a welding section. The aluminum busbars have locking grooves, and the welding sections have welding holes. The flexible flat cable includes an insulation layer and multiple conductors. Multiple welding windows are formed on the top of the insulation layer, exposing the conductors to form pads. The welding holes are welded to the pads through the welding windows. The surface of the pads has an array of pits formed by laser microtexturing. During reflow soldering, the molten solder can fully fill the pits, enhancing the shear strength and peel resistance of the solder joints, ensuring the long-term electrical insulation performance of the FFC, and reducing contact resistance and its long-term drift risk. The entire fabrication method does not require special equipment such as ultrasonic welding, which is beneficial for high-yield mass production.

Description

Technical Field

[0001] This invention relates to the field of new energy battery technology, and in particular to a battery signal acquisition integrated structure based on a flexible flat cable and its fabrication method. Background Technology

[0002] In power battery systems, the battery management system needs to acquire key parameters such as cell voltage and temperature in real time with high precision and high reliability. Currently, the mainstream acquisition solution usually adopts an integrated busbar, whose signal acquisition components mainly include flexible printed circuit boards or wire harnesses, and are connected to the cell terminals by soldering acquisition nickel sheets to realize the extraction of electrical signals.

[0003] However, existing integrated busbar structures have several significant drawbacks: First, after the acquisition signals are led out from the FPC or acquisition nickel sheet, each pin signal still needs to be transferred to the BMS interface via a multi-core harness. This transfer harness not only occupies valuable structural space inside the battery pack, but also, as the number of acquisition channels increases, the harness diameter and bending radius become larger, making it difficult to lay out the wiring in a confined space. Second, traditional harnesses are mostly made of materials such as PVC or TPE, which are prone to material fatigue, insulation damage, or even conductor breakage under repeated bending or long-term vibration conditions, affecting the long-term reliability of the system.

[0004] In existing technologies, flexible flat cables are used to replace traditional wire harnesses to improve spatial layout. However, the connection between these cables and the nickel plates still relies on reflow soldering or ultrasonic welding, which has low heat capacity and is prone to oxidation. During the welding process, problems such as poor wetting, high void ratio, and low interface bonding strength are very likely to occur. More importantly, most existing FFC pads are planar structures, and the solder relies solely on metallurgical bonding, lacking a mechanical anchoring mechanism. Under thermal stress or vibration loads, interface peeling is prone to occur, leading to a sharp increase in contact resistance or even open circuit, making it difficult to meet automotive-grade requirements. Summary of the Invention

[0005] This invention aims to at least solve the technical problems existing in the prior art. To this end, this invention proposes a battery signal acquisition integrated structure based on a flexible flat cable and its fabrication method. The flexible flat cable is small in size, ensures welding reliability, and has the characteristics of high density, high reliability, low cost, and easy automation.

[0006] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is characterized in that it includes a blister bracket, a flexible flat cable, multiple acquisition nickel plates, multiple aluminum busbars, and a connector. The blister bracket is provided with multiple grooves, and the aluminum busbars are disposed in the grooves one by one. Each end of the acquisition nickel plate is provided with a locking block and a welding part. The aluminum busbar is provided with a locking groove, and the locking block engages with the locking groove one by one. The welding part is provided with a welding hole. The flexible flat cable includes an insulation layer and multiple conductors, all of which are disposed within the insulation layer. Multiple welding windows are provided on the top of the insulation layer to partially expose the copper conductors to form a solder pad. The welding hole is welded to the solder pad through the welding window. The end of the flexible flat cable is connected to the connector. The surface of the solder pad is provided with an array of pits formed by laser microtexturing.

[0007] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided, wherein the pit depth is 5–15 μm and the diameter is 20–50 μm; the welding window and the pit array are processed in stages by a laser; the surface of the pad is provided with Sn-Bi-Ag material, and the pad and the welding hole are connected by low-temperature reflow soldering.

[0008] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided, wherein the welding window and the pit array are processed by a laser in stages, specifically including: a first stage laser energy density of 2.5–4.0 J / cm² for ablating the insulating layer, and a second stage laser energy density of 3.0–5.5 J / cm² for forming the pit array on the conductor surface.

[0009] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided, wherein the pads and the welding holes are connected by low-temperature reflow soldering. Specifically, the temperature curve of the low-temperature reflow soldering satisfies the following: the preheating stage rises from 25°C to 100°C for 60–90 seconds; the heat preservation stage rises from 100°C to 120°C for 60–80 seconds; the peak temperature of the reflow stage is 150–160°C and the liquid phase time is ≥30 seconds; and the cooling rate is ≤4°C / s.

[0010] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided, wherein the Sn-Bi-Ag material is a Sn-Bi-Ag alloy coating with a thickness of 8–15 μm.

[0011] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided, wherein the Sn-Bi-Ag material is Sn-Bi-Ag solder paste with a metal content of 88–90 wt% and a viscosity of 150–250 Pa. s.

[0012] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided on the blister bracket, wherein the multiple platforms and the multiple arc grooves are located on the same straight line, and the arc groove is provided between every two adjacent platforms, and the welding window is located on the platform.

[0013] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided, wherein the card block is U-shaped, and the two sides of the card block are provided with raised inclined surfaces, the raised inclined surfaces gradually protruding outward from the bottom to the top, and the top of the card slot near the flexible flat cable is provided with an inlet inclined surface.

[0014] According to some embodiments of the first aspect of the present invention, a battery signal acquisition integrated structure based on a flexible flat cable is provided, wherein the welding part is provided with multiple rows of welding holes, and the number of rows of welding holes corresponds to the number of conductors.

[0015] A method for fabricating a battery signal acquisition integrated structure according to some embodiments of a second aspect of the present invention, used to fabricate the battery signal acquisition integrated structure of the first aspect embodiment, includes the following steps: S1. Fabrication of flexible flat cables, blister packs, and aluminum busbars; S2. A 355nm ultraviolet laser is used to perform two-stage laser processing at the pre-set pad positions of the flexible flat cable: First stage: Laser energy density 2.5–4.0 J / cm², ablation of the insulating layer to form a welding window; Second stage: Laser energy density 3.0–5.5 J / cm², forming a micron-scale pit array on the conductor surface; S3. Clean and dry after laser processing; S4. Electroplating a Sn42 / Bi57 / Ag1 alloy coating on the surface of the pit array, or filling it with Sn-Bi-Ag solder paste by stencil printing; S5. Align and attach the flexible flat cable and the nickel strip to the blister pack; S6. Welding is completed using a reflow soldering process with a peak temperature of 150–160°C; S7. Apply adhesive to the welding area.

[0016] An integrated busbar structure based on a flexible flat cable and its fabrication method according to some embodiments of the present invention have at least the following beneficial effects: By creating a pit array formed by laser microtexturing on the surface of FFC pads, the molten solder can fully fill the pits during reflow soldering, forming a mechanical anchoring or mushroom-shaped interlocking structure after cooling. This significantly enhances the shear resistance and peel resistance of the solder joints. Using Sn-Bi-Ag material in conjunction with an optimized low-temperature reflow soldering process significantly reduces the welding heat input. This temperature is far below the decomposition temperature of the insulation layer, effectively preventing yellowing, carbonization, or blistering of the insulation layer and ensuring the long-term electrical insulation performance of FFC. The pit array not only provides mechanical anchoring but also guides the solder to spread evenly through capillary action, reducing gas residue. Combined with staged laser processing, the copper surface is ensured to be clean and its morphology controllable, significantly reducing contact resistance and its long-term drift risk. The entire preparation method does not require the introduction of special equipment such as ultrasonic welding, which is conducive to achieving fully automated, high-yield mass production.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0019] Figure 2 for Figure 1 An enlarged view of part A in the image.

[0020] Figure 3 This is a schematic diagram of the structure of the thermoforming bracket according to an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of the nickel sheet for collection according to an embodiment of the present invention.

[0022] Reference numerals: 1. Vacuum forming bracket; 2. Flexible flat cable; 3. Nickel collection sheet; 4. Aluminum busbar; 5. Connector; 6. Groove; 7. Locking block; 8. Welding part; 9. Slot; 10. Welding hole; 11. Insulation layer; 12. Conductor; 13. Welding window; 14. Arc groove; 15. Platform; 16. Positioning post; 18. Raised inclined surface; 19. Guide inclined surface; 20. First connecting hole; 21. Second connecting hole. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, left, right, front, and back, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the module or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0025] In the description of this invention, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0026] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0027] like Figures 1-4 As shown, this embodiment of the invention provides a battery signal acquisition integrated structure based on a flexible flat cable.

[0028] An integrated structure for battery signal acquisition based on a flexible flat cable includes a blister bracket 1, a flexible flat cable 2, multiple acquisition nickel plates 3, multiple aluminum busbars 4, and a connector 5. The blister bracket 1 has multiple grooves 6, and the aluminum busbars 4 are arranged in the grooves 6. The two ends of the acquisition nickel plates 3 are respectively provided with locking blocks 7 and welding parts 8. The aluminum busbars 4 are provided with locking slots 9, and the locking blocks 7 and locking slots 9 are engaged with each other. The welding parts 8 have welding holes 10. The flexible flat cable 2 includes an insulation layer 11 and multiple conductors 12. The conductors 12 are all arranged in the insulation layer 11. The top of the insulation layer 11 has multiple welding windows 13, which partially expose the conductors 12 to form solder pads. The welding holes 10 are welded to the conductors 12 through the welding windows 13. The ends of the flexible flat cable 2 are connected to the connector 5. The surface of the solder pads is provided with an array of pits formed by laser micro-texturing.

[0029] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The pit depth is 5–15 μm and the diameter is 20–50 μm. The welding window 13 and the pit array are processed in stages using a laser. The surface of the pad is covered with Sn-Bi-Ag material, and the pad and the welding hole are connected by low-temperature reflow soldering. Specifically, by limiting the pit depth of the pad surface to 5–15 μm and the diameter to 20–50 μm, and using laser processing in stages to form the welding window 13 and the pit array, while simultaneously applying Sn-Bi-Ag material to the pad surface and connecting them by low-temperature reflow soldering, the solder effectively fills and anchors the microstructure while ensuring the flexibility and insulation integrity of the FFC. This significantly improves the solder joint strength and thermal fatigue resistance, while avoiding damage to the polyimide insulation layer caused by high temperatures.

[0030] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The welding window 13 and the pit array are fabricated in stages using a laser. Specifically, the first stage uses a laser energy density of 2.5–4.0 J / cm² to ablate the insulating layer, and the second stage uses a laser energy density of 3.0–5.5 J / cm² to form the pit array on the conductor surface. Specifically, by using a first-stage laser energy density of 2.5–4.0 J / cm² to precisely ablate the insulating layer and form a clean welding window, and then using a second stage of 3.0–5.5 J / cm² to controllably form micro-textured pits on the copper conductor surface, it ensures that the PI film is completely removed without damaging the copper foil, and also constructs a tin storage structure with a regular morphology and uniform depth on the copper surface. This provides an ideal interface for subsequent solder wetting and mechanical interlocking, effectively solving the problem of copper surface oxidation or overheating that is easily caused by traditional laser windowing.

[0031] The battery signal acquisition integrated structure based on a flexible flat cable described in this embodiment, wherein the pads and the welding holes 10 are connected by low-temperature reflow soldering, specifically includes the following: the temperature curve of the low-temperature reflow soldering satisfies the following: the preheating stage rises from 25°C to 100°C for 60–90 seconds; the heat preservation stage rises from 100°C to 120°C for 60–80 seconds; the peak temperature of the reflow stage is 150–160°C and the liquid phase time is ≥30 seconds; and the cooling rate is ≤4°C / s. Specifically, by precisely controlling the low-temperature reflow soldering temperature profile as follows: preheating stage 25→100°C (60–90s), holding stage 100→120°C (60–80s), peak temperature 150–160°C with liquid phase time ≥30s and cooling rate ≤4°C / s, the wettability of Sn-Bi-Ag solder is fully activated while minimizing thermal shock, avoiding thermal degradation of the PI film, and ensuring that the solder has sufficient time to flow into the microtexture pits to reduce voids, thereby obtaining a highly reliable, low-stress welded joint.

[0032] It is understood that the pits have a depth of 5–15 μm and a diameter of 20–50 μm. Specifically, in this embodiment, the pit array is distributed in a honeycomb pattern, with a depth of 10 μm and a diameter of 30 μm.

[0033] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The Sn-Bi-Ag material uses a Sn-Bi-Ag alloy coating, specifically a Sn42 / Bi57 / Ag1 eutectic alloy with a thickness of 8–15 μm. Specifically, by setting an 8–15 μm thick Sn-Bi-Ag alloy coating on the pad surface, sufficient solder is provided to fill the microtexture pits, while excessive growth of brittle intermetallic compounds (IMCs) due to excessive coating thickness is avoided. This thickness range has been experimentally verified to balance solder saturation and long-term thermal cycling stability, significantly improving solder joint lifespan.

[0034] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The Sn-Bi-Ag material used is Sn-Bi-Ag solder paste with a metal content of 88–90 wt% and a viscosity of 150–250 Pa. Specifically, by using Sn-Bi-Ag solder paste with a metal content of 88–90 wt% and a viscosity of 150–250 Pa·s, good release properties and graphic accuracy can be ensured during stencil printing, while also possessing sufficient fluidity to fully penetrate micron-level pits during reflow, achieving dense, void-free soldering. This property parameter window is particularly well-suited to the low heat capacity characteristics of FFC thin copper foil, effectively preventing incomplete soldering or solder collapse.

[0035] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The vacuum-formed bracket 1 has multiple arc-shaped grooves 14 and multiple platforms 15, all located on the same straight line. An arc-shaped groove 14 is positioned between every two adjacent platforms 15, and the welding windows 13 are all located on the platforms 15. Specifically, by alternating platforms 15 and arc-shaped grooves 14 on the vacuum-formed bracket 1, the flexible flat cable 2 is stably supported in the platform 15 area to ensure precise alignment of the welding windows 13, while it can naturally bend and transition in the arc-shaped groove 14 area. Since the flexible flat cable 2 deforms during welding, the arc-shaped grooves 14 provide a certain range of motion and prevent damage to the conductor 12 due to localized stress during assembly or use, thus improving welding reliability and structural durability.

[0036] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. Each groove 6 is equipped with a positioning post 16, and each aluminum busbar 4 has a positioning hole. The positioning posts 16 pass through these positioning holes. Specifically, the cooperation between the positioning posts 16 and the positioning holes enables rapid and accurate positioning of the aluminum busbar 4 within the groove 6 of the vacuum forming bracket 1. This prevents the aluminum busbar 4 from shifting during subsequent assembly or under vibration conditions, ensuring the consistency of the snap-fit ​​position of the acquisition nickel sheet 3, and improving overall assembly accuracy and electrical connection reliability.

[0037] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The locking block 7 is U-shaped, with raised inclined surfaces 18 on both sides. The raised inclined surfaces 18 gradually protrude outward from the bottom to the top. The top of the slot 9 near the flexible flat cable 2 has a guide inclined surface 19. Specifically, the U-shaped locking block 7, together with the raised inclined surfaces 18 and the guide inclined surface 19 of the slot 9, forms a guiding and self-locking structure. During insertion, it automatically guides the locking block 7 into the slot 9, and after it is in place, it achieves a stable locking through the interference of the inclined surfaces. This facilitates automated assembly and prevents the nickel sheet from coming off during vibration, improving the mechanical strength and vibration resistance of the connection.

[0038] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The welding section 8 has multiple rows of welding holes 10, and the number of rows of welding holes 10 corresponds to the number of conductors 12. Specifically, during welding, each aluminum strip 4 is connected to a different conductor 12. By providing multiple rows of welding holes 10 in the welding section 8, a single type of nickel sheet can be welded according to the position of the conductor 12, facilitating the processing of the acquisition nickel sheet 3.

[0039] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The aluminum busbar 4 has two slots 9, located on its left and right sides respectively. Specifically, the slots 9 are symmetrically arranged on both sides of the aluminum busbar 4 to accommodate the corresponding nickel plates 3, further reducing processing costs.

[0040] This embodiment describes a battery signal acquisition integrated structure based on a flexible flat cable. The aluminum busbar 4 has a first connecting hole 20, and the groove 6 has a second connecting hole 21. The first connecting hole 20 and the second connecting hole 21 are correspondingly arranged. Specifically, through the alignment design of the first connecting hole 20 and the second connecting hole 21, the aluminum busbar 4 can be connected to the battery module.

[0041] This embodiment describes a battery signal acquisition integrated structure based on flexible flat cables. Two flexible flat cables 2 are provided. Grooves 6 are formed on both sides of the blister bracket 1, and aluminum busbars 4 are arranged within each groove 6. Specifically, aluminum busbars 4 and flexible flat cables 2 are arranged on both sides of the blister bracket 1 to achieve independent signal acquisition paths on both sides, improving wiring flexibility and system adaptability, while avoiding signal attenuation or wiring difficulties caused by excessive length of the flexible flat cable 2 on one side.

[0042] This invention also provides a method for fabricating a battery signal acquisition integrated structure.

[0043] A method for fabricating a battery signal acquisition integrated structure, comprising the following steps: S1. Fabrication of flexible flat cables, blister packs, and aluminum busbars; S2. A 355nm ultraviolet laser is used to perform two-stage laser processing at the pre-set pad positions of the flexible flat cable: First stage: Laser energy density 2.5–4.0 J / cm², ablation of the insulating layer to form a welding window; Second stage: Laser energy density 3.0–5.5 J / cm², forming a micron-scale pit array on the conductor surface; S3. Clean and dry after laser processing; S4. Electroplating a Sn42 / Bi57 / Ag1 alloy coating on the surface of the pit array, or filling it with Sn-Bi-Ag solder paste by stencil printing; S5. Align and attach the flexible flat cable and the nickel strip to the blister pack; S6. Welding is completed using a reflow soldering process with a peak temperature of 150–160°C; S7. Apply adhesive to the welding area; S8. Install the connector.

[0044] Understandably, a 355 nm ultraviolet laser with a pulse width of 30 ns and a frequency of 80 kHz was used. First, the PI film was ablated at an energy density of 3.0 J / cm² and a scanning speed of 800 mm / s to form welding windows 13. Keeping the spot position unchanged, the energy density was increased to 4.5 J / cm², and a spiral filling mode with an overlap rate of 80% was used to form a honeycomb array of pits 10 μm deep and 30 μm in diameter on the copper surface. After laser treatment, the surface was ultrasonically cleaned with deionized water for 5 minutes and dried at 60°C. A 10 μm thick Sn42 / Bi57 / Ag1 alloy was electroplated onto the activated copper surface. The FFC and the acquisition nickel sheet 3 were aligned and mounted, ensuring that the welding holes 10 were aligned with the pads. The surface was then placed in a reflow oven to form dense solder joints 23. X-ray inspection showed a void ratio of <8%, and the average shear strength was 16.5 N / mm.

[0045] This invention creates an array of pits on the surface of FFC pads using laser microtexture, allowing molten solder to fully fill these pits during reflow soldering. Upon cooling, this forms a mechanical anchoring or mushroom-shaped interlocking structure, significantly enhancing the solder joint's shear resistance and peel resistance. The use of Sn-Bi-Ag material combined with an optimized low-temperature reflow soldering process significantly reduces the welding heat input. This temperature is far below the decomposition temperature of the insulation layer, effectively preventing yellowing, carbonization, or blistering of the insulation layer and ensuring the long-term electrical insulation performance of the FFC. The pit array not only provides mechanical anchoring but also guides the solder to spread evenly through capillary action, reducing gas residue. Combined with staged laser processing, this ensures a clean and controllable copper surface morphology, significantly reducing contact resistance and the risk of long-term drift. The entire preparation method eliminates the need for specialized equipment such as ultrasonic welding, facilitating fully automated, high-yield mass production.

[0046] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery signal acquisition integrated structure based on a flexible flat cable, characterized in that: The device includes a vacuum forming bracket, a flexible flat cable, multiple nickel-collecting plates, multiple aluminum busbars, and a connector. The vacuum forming bracket has multiple grooves, and the aluminum busbars are arranged in the grooves. Each end of the nickel-collecting plate has a locking block and a welding part. The aluminum busbars have slots, and the locking blocks engage with the slots. The welding parts have welding holes. The flexible flat cable includes an insulation layer and multiple conductors, all of which are arranged within the insulation layer. The top of the insulation layer has multiple welding windows, which partially expose the conductors to form solder pads. The welding holes are welded to the solder pads through the welding windows. The ends of the flexible flat cable are connected to the connector. The surface of the solder pads has an array of pits formed by laser microtexturing.

2. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 1, characterized in that: The pits have a depth of 5–15 μm and a diameter of 20–50 μm; the welding window and pit array are processed in stages by a laser; the surface of the pads is covered with Sn-Bi-Ag material, and the pads and welding holes are connected by low-temperature reflow soldering.

3. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 2, characterized in that: The welding window and pit array are processed by laser in stages, specifically including: a first stage with a laser energy density of 2.5–4.0 J / cm² for ablating the insulating layer, and a second stage with a laser energy density of 3.0–5.5 J / cm² for forming the pit array on the conductor surface.

4. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 2, characterized in that: The connection between the pads and the welding holes via low-temperature reflow soldering specifically includes the following: the temperature profile of the low-temperature reflow soldering meets the following requirements: the preheating stage rises from 25°C to 100°C for 60–90 seconds; the holding stage rises from 100°C to 120°C for 60–80 seconds; the peak temperature of the reflow stage is 150–160°C with a liquid phase time ≥30 seconds; and the cooling rate is ≤4°C / s.

5. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 2, characterized in that: The Sn-Bi-Ag material uses a Sn-Bi-Ag alloy coating with a thickness of 8–15 μm.

6. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 2, characterized in that: The Sn-Bi-Ag material uses Sn-Bi-Ag solder paste with a metal content of 88–90 wt% and a viscosity of 150–250 Pa. s.

7. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 1, characterized in that: The vacuum forming bracket is provided with multiple arc-shaped grooves and multiple platforms, which are located on the same straight line. Each pair of adjacent platforms is provided with an arc-shaped groove, and the welding windows are all located on the platforms.

8. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 1, characterized in that: The card block is U-shaped, with raised inclined surfaces on both sides. The raised inclined surfaces gradually protrude outward from the bottom to the top, and the top of the card slot near the flexible flat cable is provided with an inlet inclined surface.

9. The battery signal acquisition integrated structure based on a flexible flat cable according to claim 1, characterized in that: The welding section is provided with multiple rows of welding holes, and the number of rows of welding holes corresponds to the number of conductors.

10. A method for fabricating a battery signal acquisition integrated structure, used to fabricate the battery signal acquisition integrated structure according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Fabrication of flexible flat cables, blister packs, and aluminum busbars; S2. A 355nm ultraviolet laser is used to perform two-stage laser processing at the pre-set pad positions of the flexible flat cable: First stage: Laser energy density 2.5–4.0 J / cm², ablation of the insulating layer to form a welding window; Second stage: Laser energy density 3.0–5.5 J / cm², forming a micron-scale pit array on the conductor surface; S3. Clean and dry after laser processing; S4. Electroplating a Sn42 / Bi57 / Ag1 alloy coating on the surface of the pit array, or filling it with Sn-Bi-Ag solder paste by stencil printing; S5. Align and attach the flexible flat cable and the nickel strip to the blister pack; S6. Welding is completed using a reflow soldering process with a peak temperature of 150–160°C.

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