Why is Ultrasonic Metal Welding a Necessity for New Energy Vehicles?

There are many factors to consider when deciding on a metal joining method. Depending on the application, varies based on welding design, welding materials, geometry, dimensions, and environmental influences.

We will focus on the automotive wiring harness industry to illustrate the differences between crimping, soldering, ultrasonic welding, laser welding, and resistance welding.

The initial investment in ultrasonic metal welding equipment is higher relative to other welding processes such as resistance welding, crimping, and mechanical joining, but lower than laser welding equipment.

So why is this technology dominating wire harness manufacturing and becoming a necessity for electric and hybrid vehicle batteries and power distribution systems?

Ultrasonic metal welding has dominated the automotive industry since the early 1980s, with automotive wiring harness manufacturers being the largest users of the technology. Due to its efficiency and unparalleled quality, ultrasonic welding has replaced mechanical crimping and resistance welding for all car brands almost as soon as it emerged. The use of ultrasonic welding in automotive wiring harnesses has seen even more rapid growth over the past decade due to the increase in electric vehicles (EVs).

The average wiring harness for a vehicle contains 180 ultrasonic welded joints. OEMs are adding more electronic features to cars, which requires more connectors. Together, the connectors and wire terminals form a long, complex, heavy-duty wiring harness that controls the entire electrical system throughout the vehicle.
At present, the wire harness industry still uses crimping or resistance welding for applications such as wire crimping or tin wire splicing.

The benefits of ultrasonic welding apply to thermally conductive materials such as aluminum, copper and magnesium, which can be cumbersome to weld with resistance welders and lasers. Ultrasound is also very useful for joining thin and thick materials. Ultrasonic is often the best welding process when minimizing thermal interference with material properties is required.

Therefore, starting with resistance welding and then ultrasonic welding, the welding of wires became very important. The cold melt nature of ultrasonic metal welding, its ability to eliminate oxidation before welding, the joining of dissimilar metals, extremely low energy consumption, and the ability to use one machine and the same universal tools to weld a variety of joint sizes are the reasons why ultrasonic metal wire Joints become a convincing factor in globally accepted workmanship.

Throughout the past 30 years of welding technology developments, quality and reliability have always been the ultimate deciding factors. The return on investment is easily justified — ultrasonic welded joints extend the life of the vehicle.