Optimization Design of High Frequency Piezoelectric Ultrasonic Transducer for IC Packaging

A methodology for designing high-frequency ultrasonic transducers is proposed in order to improve the speed and stability of bonding as well as the conversion efficiency of ultrasonic energy, and the phases of the design process are expressed in detail. The design process can be divided into three steps: the topology design of the components, finite element method (FEM) aided analysis optimization of the ultrasonic model and the experimental test by impedance analyzer. Based on traditional design theory to design the initial dimensions and determine the shape of every part, and then to make vibration characteristics analysis by use of ANSYS 10.0. In order to exactly simulate the piezoelectric effect, the element solid5 is utilized; meanwhile, the resonance frequency, vibration displacement nodes and the displacement when applied proper voltage can also be acquired. Considering the important factors such as the preload of bolt, an optimization ultrasonic transducer can be achieved finally. The prototyped transducer is tested through the impedance analysis, which proves remarkable resemblance with the theory and FEM analysis.