Advantages of Wire Bonding vs Spot or Laser Welding
Fusing Wires: Wire acts as a fuse. If a cell fails, it is isolated from the battery pack, allowing the remainder of the pack to continue to function as required. Thus, the pack is not destroyed by a meltdown and can be fixed at a convenient later date, ensuring no danger to life from a simple cell failure.
No Heat: Heat is dangerous for an 18650 cell and this requirement is met through the technique of wire bonding. Unlike other methods such as spot or laser welding, no heat is used in ultrasonic compression bonding. The only heat produced is localised and generated as a by-product of the friction required to make the bond. This temperate change is restricted to the outer skin of the surface only, making wire bonding ideal for work on cells which require the absence of heat.
Traceability of Each Bond: Process integrated Quality Control (PiQC) is provided in the form of a sensor integrated into the Transducer. This cutting edge and industry leading approach provides a multi-dimensional signal analysis of the bond process which calculates a bond quality index value in real-time. Using significant signals from the wire bonding process, the user is provided with instant feedback on the bonding process, ensuring high quality yields.
Clean Process: Wire bonding is a clean process. It generates no sparks, residue materials or other possible contaminations, saving time as subsequent clean-up requirements become unnecessary.
Height: Wire bonding machines are capable bonding in height variations. This means that battery packs which require variations in height for the cell and busbar can be accommodated. Our machines also provide the user with full control over the design of the final loop shape, adding additional flexibility for unique application requirements.
Testability: Ensuring the highest quality requirements, wire bonds are easily tested for reliability on bond strength. This is harder to do when using an application technique such as spotwelds which are notoriously hard to test and known industry wide for their loss of connections.
Flexibility: Wire bonding offers flexibility in the bonding process due to the wire-loop shape and material properties. For products where a certain amount of pack malleability is required – where the pack may be exposed to a certain amount of flex – damage is unlikely to take place. This is a flexibility not shared with spotwelded packs which are more rigid in form, rendering the connections easier to break following movement.
Automation: Wire bonding allows full automation of the bonding process with CNC machines for higher efficiency and quality. In turn, this decreases the amount of manual labour required for system use.