为提高热超声封装效率、降低封装温度,研究了高频超声换能器的动力学优化设计.基于一维振动和波动理论,建立了换能器的解析模型,得到了压电振子、指数形聚能器和劈刀的波动方程.借助有限元分析软件ANSYS参数化建模,分别对压电振子和聚能器进行优化设计.考虑材料、形状和尺寸对其振动特性的影响,得到了换能器最优模型.通过阻抗分析仪和多普勒激光测振仪对换能器进行电谐振和机械谐振测试.实验结果表明,该换能器在其工作频率附近不存在非纵振模态和其它寄生的振动形式,从而方便了超声信号发生器设计.
The dynamic optimum design of high-frequency ultrasonic transducer was studied to improve thermosonic packaging efficiency and reduce packaging temperature. Based on one-dimensional vibration and wave theories, the analytical model of a transducer was established, and the wave equations of piezoelectric converter, exponential con- centrator and capillary were gained. By using ANSYS software parametric design language for finite element analysis, the optimum design of piezoelectric converter and concentrator were accomplished respectively. Considering the influence of material, shapes and dimensions on the characteristics of the transducer, the optimum model of the transducer was achieved. The electrical resonance and mechanical vibration characteristics were tested by impedance analyzer and laser Doppler vibrometer. Experimental results show that there are no non-axial vibration modes and other spurious resonances around working frequency, thus it is convenient for the design of ultrasonic generator.