What is Ultrasonic Soldering?

When ultrasonic vibration is applied to the solder in a tank, many cavitation bubbles are created. The size of the bubbles increases until they become unstable and implode. When a bubble implodes, the solder around the bubble accelerates toward the bubble's middle. This solder can then hit the surface of a part, creating a strong impact, which simultaneously cleans the part's surface and destroys the oxide film on the metal. This allows soldering without using flux.

The use of ultrasonic soldering also reduces the surface tension of the solder, decreasing the likelihood of solder bridges, and creating a more uniform thickness of solder.