Model-based dynamic characteristics investigation of ultrasonic transducers for MEMS packaging

To provide faster, more repeatable and stronger MEMS packaging technology, the dynamic characteristics of ultrasonic transducers are studied using finite element method (FEM), and the ultrasonic generator for driving the transducer is also presented in this paper. The finite element model of the high frequency ultrasonic transducer was established by using ANSYS software, and the vibration characteristics of the transducer in free and constrained states were analyzed, respectively. The vibration modes of the transducer were gained through modal analysis. The steady and transient responses were figured out using harmonic and transient analysis, respectively. The ultrasonic generator with phase loop lock (PLL) was designed on the basis of complex programmable logic device (CPLD). Laser Doppler measurements were carried out to investigate the dynamic characteristics of the transducer, and the experiment results are in good agreement with the FEM results. The characteristics of the ultrasonic generator were examined, and the results show that it has good performance, and thus the ultrasonic transducer system can fulfill finer packaging.