Standing Wave Phenomena Relating to Ultrasonic Bonding Tips

This paper analyzes the required geometry of a tapered tip that terminates the amplifying horn used for ultrasonic bonding of fine wires to small electronic circuit boards. Nearly all the published literature on the ultrasonic bonding power train is concerned with the amplifying horn rather than with the bonding tip. The new application of the ultrasonic bonding technique described here is for circuit boards of extremely high wire density, where the slender bonding tip must penetrate the circuit network to bond a wire to a pad without disturbing the neighboring bonds.