Ultrasonic soldering is process that uses ultrasonic energy to solder materials, such as glass, which can not be soldered using conventional means. Ultrasonic soldering is a distinctly different process than ultrasonic welding. Ultrasonic welding uses ultrasonic energy to join parts without adding any kind of filler material while ultrasonic soldering uses a filler material, namely solder, to form a joint. Ultrasonic soldering can be done with either a specialized soldering iron or a specialized solder pot. In either case the process can be automated for large-scale production or can be done by hand for prototyping or repair work.