Abstract: An ultrasonic transducer, bonding tool and method of bonding gold or gold plated leads to gold or gold plated bonding pads located on unheated substrates is disclosed. More particularly, the transducer of the present invention incorporates a modified transducer/tool interface which provides for increased durability as well as increased excursion control of any bonding tool placed therein. The bonding tool of the present invention includes a modified end having a raised pattern used to form an impression in the lead to be bonded to enhance gripping of the lead during bonding. The preferred methods include using the modified transducer and bonding tool to perform gold-to-gold bonding on unheated substrates while providing increased vertical clearance for bonding between structures.