Ultrasonic welding is a friction welding process that can be used to weld many thermoplastic products. High-frequency vibration is used to generate such welding friction heat. In ultrasonic welding, a high-frequency dynamic electric field is generated by tuning a metal horn in contact with a bonding substrate. The high-speed vibration of the metal anvil creates friction with the fixed substrate, which generates a large amount of heat at the bonding interface. The welding is completed by pressurizing and cooling, and the formed joint has high strength.