Ultrasonic welding (UW), as a solid-state joining process, uses an ultrasonic energy source (usually with a frequency of 20 kHz or above) to induce oscillating shears between the faying surfaces to produce metallurgical bonds between a wide range of metal sheets [1, 2], thin foils [3], semiconductors [4], plastics [5], glass [6], and ceramics [7]. In contrast to traditional fusion welding processes, ultrasonic welding has several inherent advantages [3,8] derived from its solid-state process characteristics, and has been in use as a versatile joining method in the electronics, automotive, and aerospace industries since the 1950s