Investigator: Teresa Franklin
Ultrasonic welding is another process in which ultrasonic energy is used to create a solid-state bond between two pieces of metal. The mechanism of creation of a solid state bond is that the ultrasonic interfacial motion between the two mating surfaces breaks and disperses the surface oxides, dirt and other contaminants leaving clean intimate surfaces which then create bonds. Ultrasonic welding is a versatile and powerful joining technique in the microelectronic packaging industry because of the low temperature, high yield rate and flexibility of the process. There are four basic process variations of ultrasonic welding, used to produce different types of welds: spot, ring, line, and continuous seam welds.
An ultrasonic spot welding machine at Oak Ridge National Laboratory.
A cross sectional view of a magnesium/steel ultrasonic spot weld. (Santella et al., 2010)