Frequency characteristics of ultrasonic wire bonding using high frequency vibration systems of 40 kHz to 780 kHz

Welding characteristics of ultrasonic wire bonding for IC or LSI using 40 kHz to 780 kHz linear vibration welding systems are studied to improve the welding characteristics. Welding specimens used are soft and hard aluminum wires 0.1 mm and 0.03 mm in diameter, and copper plates 1.0 mm in thickness as a lower specimens. Frequency characteristics of required welding tip vibration amplitude and velocity for sufficient welding of these specimens are measured. Temperature rises at welding surface are measured by thermo-electric-motive force between aluminum and copper specimens and the maximum temperature measured is about 300 degrees centigrade.