In recent years, with the continuous development of the new energy vehicle industry, the power core technology of electric vehicle batteries has been iteratively evolving. As one of the main components of battery pack modules, the CCS (Cell Connection System) integrated busbar has gradually gained attention within the industry in the past few years. It has been continuously evolving towards higher safety, higher integration, system lightweighting, and lower costs.

In early battery pack designs, battery modules were electrically connected through wiring, and then voltage sampling lines were connected to the busbars to collect cell voltages. Temperature sensors, such as thermistors, were separately installed to collect temperature data from specific locations. The CCS integrated busbar integrates components such as electrical connection busbars, signal acquisition FPCs, plastic structural parts, temperature-sensing thermistors, and BMS CAN communication interfaces into a single unit.

    The structural parts provide structural support and strength. They are generally made of materials like PC and are manufactured using injection molding or vacuum forming processes. Some structural parts are directly made by thermally compressing insulation films with busbar FPCs and other components. The specifications, dimensions, and tolerances of the integrated busbar need to be determined based on the module design.

The FPC is primarily responsible for connecting the cells to the Module Management Board (BMB) through the BMS CAN bus, collecting information such as cell voltage, current, and temperature. It is generally connected to the cells via nickel strips and to the busbars through laser welding. Thermistors are also placed on the FPC to collect temperature data from specific locations within the module. Since thermistors cannot directly contact the cells, they are typically attached to the cells using thermal conductive silicone pads. The FPC is usually compounded with the structural parts through heat staking, adhesive bonding, or thermal compression.

The connection busbars, typically made of aluminum or copper (copper is less commonly used due to cost and welding process reliability issues with copper-aluminum connections), are used to achieve series and parallel connections between cells. The busbars are fixed to the structural parts using methods such as structural part clips, heat staking, or thermal compression. To ensure electrical performance testing, the busbars and FPCs need to be connected through laser welding, achieving specific connection strength and internal resistance requirements. The busbars are connected to the cell terminals through laser welding. The design and connection of the busbars must meet the overall module design's current-carrying capacity requirements. The laser welding of the busbars must achieve specific melting depth, width, and cross-sectional area to ensure welding quality and reliability. The positional accuracy of the busbars also significantly impacts the module's welding process. Additionally, fuse devices need to be designed at specific locations to act as module fuses.

After the structural parts have undergone the installation of busbars and FPCs, as well as the corresponding heat staking and welding processes, connection performance tests are conducted. These tests include communication interface connectivity testing, welding internal resistance four-probe detection, visual inspection, and positional accuracy testing. After completing these tests, the final packaging and warehousing are carried out.