Ultrasonic composite vibration device and ultrasonic bonding device

An ultrasonic composite vibration device, which is an ultrasonic composite vibration element that induces composite vibration by synthesizing longitudinal vibration and torsional vibration, comprising:

• a first vibration element having an electrostrictive transducer that generates the longitudinal vibration;
• and a second vibration element having a slit and a frequency adjustment element for converting the longitudinal vibration into the torsional vibration,
• wherein the first vibration element and the second vibration element are co-axially connected at a first designated connection location which is included in a range within a phase angle of 0.05 π based on antinodes of a standing wave of the longitudinal vibration, and is included in a range within a phase angle of 0.22 π based on nodes of a standing wave of the torsional vibration, and
• the first vibration element or the second vibration element is configured to be supported in a designated support location where a node of at least one of the standing wave of the longitudinal vibration and the standing wave of the torsional vibration is present.