A CCS integrated assembly based on ultrasonic direct welding technology

Abstract

This utility model discloses a CCS integrated component based on ultrasonic direct welding technology, including an FPC assembly, a positioning bracket, and a busbar. The FPC assembly includes an FPC body and multiple pressure sampling branches and multiple temperature sampling branches extending from the FPC body. The ends of the pressure sampling branches are provided with pads, which are welded to the corresponding busbars using ultrasonic direct welding technology for collecting cell voltage. The temperature sampling branches are welded with NTC chips and attached to the cell cover via thermally conductive silicone pads for collecting cell temperature. The positioning bracket is fixedly connected to the busbar to clamp and fix the relative positions of the pressure sampling branches and the busbar, and to clamp and fix the relative positions of the temperature sampling branches and the cell cover. The significant features of this CCS component are: it can use ultra-thin FPCs; it has a fast welding speed and a short process flow, meeting the requirements of automated production line cycle time (welding cycle < 0.5s) and zero defect rate (PPM ≤ 50).

Description

Technical Field

[0001] This utility model belongs to the field of new energy power battery module manufacturing technology, and in particular relates to a CCS integrated component based on ultrasonic direct welding technology. Background Technology

[0002] With increasing global emphasis on environmental protection and sustainable development, the new energy vehicle industry has ushered in unprecedented development opportunities. Among them, the Combined Charging System (CCS), as a key component of new energy vehicle charging technology, is gradually becoming the focus of industry attention. CCS technology integrates DC fast charging and AC slow charging functions, aiming to simplify the charging method of electric vehicles, improve charging efficiency, and provide drivers with a more convenient charging experience.

[0003] Laser welding technology plays a vital role in the manufacturing of CCS (Cells Contact System) for new energy vehicles due to its advantages such as high energy density, high precision, and high efficiency. In the production process of CCS integrated busbars (also known as battery cover assemblies), laser welding technology is widely used for welding components such as conductive busbars and control circuits.

[0004] In new energy vehicle battery systems (such as CCS), the reliability, cost, and efficiency of metal bonding processes directly affect battery performance and production costs. While current mainstream laser welding technology is widely used in nickel sheet bonding, it still has the following significant drawbacks:

[0005] 1. Heat input and material compatibility issues: Laser welding relies on high energy to melt metal to achieve connection. Its heat-affected zone (HAZ) is prone to causing local deformation of nickel sheets or substrates. Furthermore, it has low welding efficiency for high reflectivity materials (such as aluminum and copper), requiring additional surface coating treatment to reduce reflection loss, which increases process complexity and cost.

[0006] 2. High process sensitivity: Welding quality is extremely sensitive to workpiece gap, alignment accuracy (usually <0.1mm) and surface cleanliness (such as oxides and oil stains). Small deviations can easily cause defects such as porosity and cracks. High-precision fixtures and real-time monitoring systems are required, which further increases the investment in equipment.

[0007] 3. Long-term risks under dynamic load: The joint formed by fusion welding may develop fatigue microcracks due to thermal stress concentration during battery charge and discharge cycles, posing a potential failure risk with long-term use.

[0008] In recent years, ultrasonic direct welding technology, with its unique welding principle and advantages, has been widely used in the manufacturing of CCS (Computer-on-Shipment) systems for new energy vehicles. Ultrasonic direct welding technology achieves the electrical connection between the FPC (Flexible Printed Circuit) and the busbar, and realizes solid-phase diffusion bonding between metal atoms through high-frequency mechanical vibration. Using ultrasonic direct welding technology in CCS integrated components ensures product reliability while reducing the types of parts and the cost of tooling and fixtures. This facilitates the integration of different technologies and products with different needs, filling the market gap for low-cost CCS integrated components. Utility Model Content

[0009] The present invention aims to provide a CCS integrated component based on ultrasonic direct welding technology, the technical solution of which is as follows:

[0010] A CCS integrated component based on ultrasonic direct welding technology includes an FPC assembly, a positioning bracket, and a busbar;

[0011] The FPC assembly includes an FPC body and multiple pressure sampling branches and multiple temperature sampling branches extending from the FPC body;

[0012] The end of the pressure sampling branch is provided with a solder pad, and the solder pad and the corresponding busbar are welded together by ultrasonic direct welding technology for collecting cell voltage.

[0013] The upper surface of the temperature-collecting branch is welded with an NTC chip, and its lower surface is attached to the cell cover by a thermally conductive silicone pad for collecting cell temperature.

[0014] The positioning bracket and the busbar are fixedly connected and used to clamp and fix the relative positions of the pressure sampling branch and the busbar, as well as the relative positions of the temperature sampling branch and the battery cell cover.

[0015] Furthermore, the pads of the pressure-collecting branch are designed for ultrasonic direct welding: the pad size is larger than the size of the ultrasonic direct welding head; the welding surface of the busbar is designed for ultrasonic direct welding: the microstructure of the welding surface is formed by laser engraving to create honeycomb-shaped grooves.

[0016] Furthermore, the temperature sampling branch includes:

[0017] FPC temperature sampling branches extend from both sides of the FPC body and are equipped with NTC pads;

[0018] The NTC chip is soldered to the upper surface of the FPC temperature sampling branch;

[0019] The FR4 dielectric sheet, with NTC clearance holes, is attached to the upper surface of the FPC temperature sampling branch;

[0020] Thermally conductive photocurable adhesive is filled into the NTC clearance holes of the FR4 dielectric sheet to cover the NTC chip;

[0021] Steel sheets are attached to the lower surface of the FPC temperature sampling branch to enhance the strength and flatness of the FPC temperature sampling branch;

[0022] During assembly, a thermally conductive silicone pad is placed between the steel sheet and the top cover of the battery cell.

[0023] Furthermore, the FPC temperature sampling branch, FR4 dielectric sheet, and steel sheet are provided with monitoring holes for vertical alignment of the three components.

[0024] Furthermore, the FPCs of the temperature sampling branch and the pressure sampling branch adopt a U-shaped anti-core expansion structure and a flexible connection with the FPC body.

[0025] Furthermore, the main body of the busbar is a flat, thin sheet of metal, partially overlapping with the FPC temperature sampling branch and the FPC pressure sampling branch. This overlapping area is the location of the temperature acquisition point or the ultrasonic direct welding point; each busbar is equipped with:

[0026] Laser welding monitoring hole, used to guide the laser welding positioning of busbar and cell electrodes;

[0027] Pin positioning holes are used for welding and positioning of the busbar and the cell electrodes;

[0028] An anti-cell expansion arch structure is placed between two welding points on the busbar to relieve stress at the two welding points.

[0029] Furthermore, a PET protective film is attached to the upper surface of the FPC assembly, and the PET protective film has windows in the following positions: explosion-proof valve position, busbar positioning hole, cell welding position, ultrasonic direct welding position, NTC position, busbar arch structure position, and busbar spacing position.

[0030] Furthermore, a structural bracket is installed on the surface of the FPC assembly. The structural bracket has windows in the following locations: explosion-proof valve location, busbar positioning hole, battery cell welding location, ultrasonic direct welding location, NTC location, busbar arch structure location, and busbar interval location, and is equipped with FPC positioning rivets and busbar positioning rivets.

[0031] Furthermore, the FPC assembly, the busbar, and the battery cell are assembled in parts using a fixture, and the FPC assembly is directly attached to the battery cell cover using double-sided adhesive foam.

[0032] Furthermore, the locking end of the busbar is treated by laser welding of nickel sheets or nickel plating.

[0033] Compared with the prior art, the significant features of this utility model CCS component are:

[0034] Ultra-thin FPCs can be used;

[0035] It features fast welding speed and short process flow, meeting the requirements of automated production line cycle time (welding cycle < 0.5s) and zero defect rate (PPM ≤ 50). Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the stacked structure of the CCS component of this utility model;

[0037] Figure 2 This is a schematic diagram of the FPC assembly of the CCS component of this utility model;

[0038] Figure 3 This is an enlarged view of the temperature-sensing branch stacked structure of the FPC assembly;

[0039] Figure 4 This is a schematic diagram of the pressure-collecting branch of the FPC assembly;

[0040] Figure 5 This is a schematic diagram of the busbar structure of the CCS component of this utility model;

[0041] Figure 6 This is a schematic diagram of the structure of the PET insulating film of the CCS component of this utility model;

[0042] Figure 7 This is a schematic diagram of the structure of the second embodiment of the CCS component of this utility model;

[0043] Figure 8 This is a structural schematic diagram of the third embodiment of the CCS component of this utility model;

[0044] Figure 9 This is a schematic diagram of the hot pressing process for the CCS component manufacturing process of this utility model.

[0045] Figure 10 This is a schematic diagram of the ultrasonic direct welding machine. Detailed Implementation

[0046] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0047] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0048] like Figure 1As shown, this utility model provides a CCS integrated component based on ultrasonic direct welding technology, which is mainly composed of PET insulating film 1, FPC assembly 2, busbar 3, plastic bracket 4, 5, fire-resistant tape 6, etc.

[0049] like Figure 2 As shown, the FPC assembly 2 is divided into the following components according to function: FPC body 210, temperature sampling branch 220, pressure sampling branch 230, and terminals 240 and connector sheaths 250 located at the head end of the FPC body 210.

[0050] Multiple temperature sampling branches 220 and pressure sampling branches 230 are led out from both sides of the FPC main body 210 to collect the temperature and voltage of each cell.

[0051] The FPC assembly 2 is equipped with multiple temperature sampling branches 220. The temperature sampling branch 220 is composed of FPC branch 221, NTC chip 222, thermally conductive photocurable adhesive 223, FR4 dielectric sheet 224 and steel sheet 225.

[0052] In FPC assembly 2, FPC 201 uses a single-layer circuit. In specific applications, FPC 201 can also be a double-sided board, a rigid-flex board, etc. Preferably, the thickness of the substrate copper foil can be selected from, but is not limited to, 12 micrometers to 70 micrometers. Preferably, the pads of FPC assembly 2 are single-sided open, and can be placed on the front or back (the bare copper side of the pad should face the bus).

[0053] Terminal 240 is electrically connected to the FPC head pad using a piercing crimping method. Then the FPC is folded, and terminal 240 is pushed into connector sleeve 250 to form an assembly.

[0054] Preferably, the FPC pressure branch 231 adopts a U-shaped anti-cell expansion structure, which can reduce the force exerted on the FPC by the deformation of the cell during charging and discharging, and improve the reliability of the product.

[0055] The FPC pressure branch 231 has a solder pad 2311 at its end, and the solder pad is welded using ultrasonic direct welding technology. Preferably, the solder pad is designed for compatibility: the size of the solder pad is larger than the size of the ultrasonic direct welding head.

[0056] Preferably, to ensure that the pads are not contaminated or oxidized and to reduce contact resistance, the protection methods include: using a surface composite plating layer for copper foil protection (chemical nickel nano-silver / gold transition layer to reduce contact resistance); or surface OSP (organic solderability protectant) protection for copper foil; or surface passivation protection for copper foil.

[0057] The front side of the FPC temperature sampling branch 221 is used for reflow soldering of the NTC chip 222. Preferably, after soldering the NTC chip 222, an FR4 dielectric sheet 224 is used for protection, followed by thermally conductive photocurable adhesive for protection and heat transfer. Then, a steel sheet 225 is attached to the back side for heat conduction and to improve strength. Finally, a thermally conductive silicone pad is attached to the steel sheet. After assembly, the assembly is attached to the busbar 3 via the thermally conductive silicone pad.

[0058] FPC temperature sampling branch 221 is fixed to the busbar via plastic bracket 4. The main function of the plastic bracket is:

[0059] By engaging with the busbar, the plastic bracket 4 presses down on the FR4 dielectric sheet 224 next to the NTC chip 222, ensuring the thermally conductive silicone pad 226 is tightly attached to the cell cover, thus establishing a reliable heat conduction channel: heat is transferred to the NTC chip 222 through the thermally conductive silicone pad 226, steel sheet 225, FPC, and thermally conductive UV-cured adhesive 223, thereby directly acquiring the temperature of the cell cover 8. The plastic brackets 4 and 5 need to be used in conjunction with the busbar 3 to secure the connection between the temperature acquisition branch 220 and the busbar 3. Preferably, the plastic bracket 4 is designed with an NTC monitoring hole and a thermally conductive silicone monitoring hole, allowing for accurate alignment during installation and providing protection for the connection between the temperature acquisition branch 220 and the busbar 3.

[0060] Optionally, the NTC chip is soldered onto the FPC body, and the temperature signal of the bus is acquired through the bus, FPC pads (wires), thermally conductive photocurable adhesive, and NTC.

[0061] like Figure 5 As shown, the busbars of CCS integrated components based on ultrasonic direct welding technology mainly include the following types: positive and negative output busbars 310 and 320, bridging busbar 330, and ordinary series busbar 340, etc. Among them, the main body of busbar 3 is a flat, thin sheet of metal, which partially overlaps with the FPC temperature sampling branch and FPC pressure sampling branch. This overlapping area is the location of the temperature acquisition point or the ultrasonic direct welding point.

[0062] Preferably, the busbar 3 is provided with a laser welding monitoring hole 301 (at the welding position of the battery cell), a pin positioning hole 302, and an anti-expansion arched structure 303. The laser welding monitoring hole 301 is used to guide the laser welding positioning of the busbar and the battery cell electrodes; the pin positioning hole 302 is used for welding positioning of the busbar and the battery cell electrodes; and the anti-expansion arched structure 303 is disposed between two welding points of the busbar to relieve stress at the two welding points.

[0063] Preferably, the locking terminals of the positive and negative output busbars are laser-welded with nickel sheets or nickel-plated.

[0064] Preferably, the microstructure of the welding surface 305 of the busbar 3 uses laser-engraved honeycomb grooves to increase the mechanical interlocking effect.

[0065] Preferably, the busbar surface pretreatment is: plasma cleaning + in-situ generation of an Al2O3 passivation layer (thickness <10nm).

[0066] like Figure 6 As shown, the PET insulating film 1 needs to have windows in the following locations: explosion-proof valve location 102, busbar positioning hole 105, battery cell welding location 106, ultrasonic direct welding location 103, NTC location 104, busbar arch structure location 107, and busbar spacing location 108.

[0067] Preferably, the PET insulating film 1 can be replaced by a vacuum forming / injection forming bracket 7, such as... Figure 7 As shown. Preferably, the thermoforming / injection molding bracket 7 includes a busbar composite, an FPC assembly composite, a positioning bracket composite, etc., for positioning the busbar 3 and the FPC assembly 2.

[0068] Preferably, the vacuum forming / injection forming bracket 7 is provided with a busbar positioning rivet 702 and an FPC positioning rivet 706 at the composite position for positioning and hot riveting fixation of the busbar and FPC assembly.

[0069] Preferably, the vacuum forming / injection forming bracket 7 needs to be avoided or have openings at the explosion-proof valve position 701, the busbar positioning hole 705, the battery cell welding position 706, the ultrasonic direct welding position 703, the NTC position 704, the positioning bracket position, and the busbar arch structure position.

[0070] Optionally, the PET insulating film can be replaced by assembling individual components using a jig, such as... Figure 8 As shown. The positions of bus 3 and FPC assembly 2 are fixed by a fixture, and laser welding of the bus to the battery cell and ultrasonic direct welding of the bus to the FPC assembly are performed directly on the battery cell. The FPC assembly 2 is fixed by directly bonding it to the top cover of the battery cell with double-sided adhesive foam 9.

[0071] like Figure 9 As shown, taking hot-pressed CCS components as an example, their manufacturing process includes assembly, hot pressing, welding, and bonding, as explained below:

[0072] First, an aluminum pressing mold is placed on the guide rails of the hot pressing system. On the lower mold, fiberglass cloth, silicone, another layer of fiberglass cloth, a PET insulating film, two FPC assemblies, a positioning bracket, a busbar (for some temperature-sensing locations, the busbar and positioning bracket are assembled first), another layer of fiberglass cloth, silicone, another layer of fiberglass cloth, and finally the upper mold are placed in sequence. Then, the mold is placed in the hot press, and the hot pressing parameters are set to press the above parts into a single unit. The fiberglass cloth-silicone-fiberglass cloth composite layer protects the mold and the product and provides release capability.

[0073] Then, the semi-finished product is placed in an ultrasonic direct welding machine for ultrasonic direct welding, connecting the welding pads and busbars of the pressure branch. The ultrasonic direct welding machine includes an intelligent welding head module, an electroacoustic converter structure, an infrared thermal imager, and an AI vision camera. Figure 10 As shown.

[0074] The advantages of using ultrasonic direct welding are as follows:

[0075] 1. No need to melt the metal, completely eliminating the heat-affected zone and achieving metallurgical bonding between FPC copper foil and busbar (aluminum / copper);

[0076] 2. Handling micro-scale connections (solder joint size ≤ 1mm) between ultra-thin FPCs (thickness ≤ 0.1mm) and busbars. 2 By precisely controlling energy, damage to the FPC substrate is avoided, and the heat-affected zone is ≤0.1mm.

[0077] Finally, thermally conductive silicone pads are attached to the steel sheet positions of the FPC assembly, and fire-resistant tape is attached to the crossover bus positions at the rear.

[0078] Compared with the prior art, the present invention has the following advantages:

[0079] Soldering of CCS components suitable for ultra-thin FPCs;

[0080] It features fast welding speed and short process flow, meeting the requirements of automated production line cycle time (welding cycle < 0.5s) and zero defect rate (PPM ≤ 50).

[0081] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A CCS integrated component based on ultrasonic direct welding technology, characterized in that, Includes FPC assembly, positioning bracket, and busbar; The FPC assembly includes an FPC body and multiple pressure sampling branches and multiple temperature sampling branches extending from the FPC body; The end of the pressure sampling branch is provided with a solder pad, and the solder pad and the corresponding busbar are welded together by ultrasonic direct welding technology for collecting cell voltage. The upper surface of the temperature-collecting branch is welded with an NTC chip, and its lower surface is attached to the cell cover by a thermally conductive silicone pad for collecting cell temperature. The positioning bracket and the busbar are fixedly connected and used to clamp and fix the relative positions of the pressure sampling branch and the busbar, as well as the relative positions of the temperature sampling branch and the battery cell cover.

2. The CCS integrated component as described in claim 1, characterized in that, The pads of the pressure-collecting branch are designed for ultrasonic direct welding: the pad size is larger than the size of the ultrasonic direct welding head; the welding surface of the busbar is designed for ultrasonic direct welding: the microstructure of the welding surface is formed by laser engraving to create honeycomb-shaped grooves.

3. The CCS integrated component as described in claim 1, characterized in that, The temperature sampling branch includes: FPC temperature sampling branches extend from both sides of the FPC body and are equipped with NTC pads; The NTC chip is soldered to the upper surface of the FPC temperature sampling branch; The FR4 dielectric sheet, with NTC clearance holes, is attached to the upper surface of the FPC temperature sampling branch; Thermally conductive photocurable adhesive is filled into the NTC clearance holes of the FR4 dielectric sheet to cover the NTC chip; Steel sheets are attached to the lower surface of the FPC temperature sampling branch to enhance the strength and flatness of the FPC temperature sampling branch; During assembly, a thermally conductive silicone pad is placed between the steel sheet and the top cover of the battery cell.

4. The CCS integrated component as described in claim 3, characterized in that, The FPC temperature sampling branch, FR4 dielectric sheet, and steel sheet are equipped with monitoring holes for vertical alignment.

5. The CCS integrated component as described in claim 1, characterized in that, The FPCs of the temperature and pressure sampling branches adopt a U-shaped anti-core expansion structure and a flexible connection with the FPC body.

6. The CCS integrated component as described in claim 1, characterized in that, The main body of the busbar is a flat, thin sheet of metal, partially overlapping with the FPC temperature and pressure sampling branches. This overlapping area is where temperature acquisition points or ultrasonic direct welding points are located. Each busbar is equipped with: Laser welding monitoring hole, used to guide the laser welding positioning of busbar and cell electrodes; Pin positioning holes are used for welding and positioning of the busbar and the cell electrodes; An anti-cell expansion arch structure is placed between two welding points on the busbar to relieve stress at the two welding points.

7. The CCS integrated component as described in claim 1, characterized in that, A PET protective film is attached to the upper surface of the FPC assembly. The PET protective film has windows in the following locations: explosion-proof valve location, busbar positioning hole, cell welding location, ultrasonic direct welding location, NTC location, busbar arch structure location, and busbar spacing location.

8. The CCS integrated component as described in claim 1, characterized in that, A structural bracket is mounted on the surface of the FPC assembly. The structural bracket has windows in the following locations: explosion-proof valve location, busbar positioning hole, battery cell welding location, ultrasonic direct welding location, NTC location, busbar arch structure location, and busbar interval location. FPC positioning rivets and busbar positioning rivets are also provided.

9. The CCS integrated component as described in claim 1, characterized in that, The FPC assembly, busbar, and battery cell are assembled in parts using a fixture, and the FPC assembly is directly attached to the battery cell cover using double-sided adhesive foam.

10. The CCS integrated component as described in claim 1, characterized in that, The locking terminals of the busbar are treated by laser welding of nickel sheets or nickel plating.

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