Here is the abstract you requested from the Wirebond_2010 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Active and Semi-Active Vibration Control of Ultrasonic Bonding Transducers|
|Keywords: Wire Bonding, Ultrasonic Transducer, Active and Semi-Active Control|
|One key component of wire bonding machines is the ultrasonic transducer, which generates the required vibration for the bonding process. Such a transducer must be carefully designed and will be driven in its longitudinal vibration mode. The longitudinal modes are typically not perfectly symmetric and show unwanted vibrations orthogonal to the main bonding direction. Generally, beside this eigenmode additional parasitic vibration modes exist. These eigenmodes, e.g. bending modes of the transducer, also lead to fluctuating normal forces in the friction contact and can therefore disturb the bonding process. A novel prototype transducer is presented, which is capable to suppress these unwanted vibrations using additional piezoelectric actuators. The conventional ultrasonic transducer has been described by a Finite-Element model. The best location of the additional piezo actuators is obtained based on the electromechanical coupling with the new control actuators. This can be described by the generalized coupling coefficient, which relates the transferred energy with the total energy in the system. In general, this coefficient depends on the vibration mode. In this case the main longitudinal mode of the transducer should not be influenced, while the coupling with orthogonal vibration modes is to be maximized. Active and semi-active control techniques are investigated. The latter one can be done by shunting the piezoceramics to passive inductance-resistance networks. Tuning the electrical resonance frequency to the operating frequency results in an absorbing effect and ideal longitudinal vibrations of the tool.|
|Dr.-Ing. Marcus Neubauer,
Leibniz University Hannover