Stamping/Laser Cutting:
Burr Control: Burrs generated by stamping are a potential risk point for high-voltage breakdown and must be thoroughly removed using precision molds or subsequent deburring processes (such as vibration grinding or chemical polishing).
Dimensional Accuracy: Ensure the position and dimensional accuracy of each mounting and positioning hole to ensure smooth assembly within the battery pack.
Bending:
Avoiding Cracks: A too small bend radius can cause cracking on the outside of the copper busbar. An appropriate bend radius must be set based on the material type and thickness (generally, the R angle should be ≥ 1 times the material thickness).
Springback Control: Copper is elastic and will rebound after bending. Springback must be compensated for through mold design and process parameters to ensure accurate bend angles.
Welding:
Welding the copper busbar to the battery cell terminals (usually aluminum), sensors, sampling cables, etc. is a critical process.
Ultrasonic Welding: Suitable for copper-aluminum dissimilar metal welding. Welding energy, pressure, and time must be strictly controlled, and 100% non-destructive testing (such as tensile testing and solder joint quality analyzers) must be performed to ensure weld strength and quality.
Laser welding: Concentrated energy minimizes deformation. Shielding gas, power, and speed must be carefully controlled to prevent porosity, spatter, and cold solder joints.
Surface Treatment/Plating:
Pre-treatment: Before plating, the copper busbar must be thoroughly cleaned, degreased, and pickled to ensure an absolutely clean surface. Failure to do so will result in poor plating adhesion, blistering, and flaking.
Plating Thickness Uniformity: The plating thickness must be uniform and meet specifications, especially around corners. It must not be too thin.
Insulation:
Tubing/Heat Shrink Tubing: Ensure complete coverage and a tight fit after heat shrinking, without wrinkles or damage.
Injection Molding/Overmolding: Control the injection molding process to prevent flash, missing material, or internal stress, and ensure the integrity of the insulation layer.
Although small, copper busbars for new energy vehicles have a profound impact on the entire system. Their production is a systematic project, requiring close coordination among design, materials, processes, and quality inspection. Only by consistently focusing on the core goals of "low resistance, high safety, and high reliability" can we produce high-quality products that meet stringent automotive-grade requirements.