热超声键合压电换能器的动力学特性

基于有限元方法和试验测试，研究了芯片封装用压电超声换能器的动力学特忡。借助ANSYS压电耦合和非线性接触分析功能，对换能器自由和约束状态下的振动特性进行了分析。探讨了超声能量在空间域、时域和频域的传递规律。由模态分析得到换能器的振动形式，通过谐响应分析提取其在正弦电压激励下的振动信息，经瞬态分析获得换能器的瞬态响应。结果表明，螺栓径向尺寸和预紧力影响换能器的模态分布和动态特性，压电晶堆加载电压的频率影响超声能量传递特性。通过键合试验考察了焊点质量与螺栓径向尺寸的关系。分析和试验结果为换能器设计和键合工艺优化提供了指导。

Dynamic characteristics study of piezoelectric transducer for thermosonic bonding

The dynamic characteristics of piezoelectric ultrasonic transducer for IC packaging were studied based on finite element method (FEM)and experiment.With the help of ANSYS piezoelectric couple and nonlinear contact analysis function, the vibration characteristics of transducer in free and constrained states were analyzed respectively.The rule of ultrasonic energy transmission in spatial domain, time domain and frequency domain were discussed. Through modal analysis, the vibration modes of transducer were gained.The vibration information of transducer driven by sinusoidal voltage was obtained by use of harmonic response analysis.The transient response was figured out by transient analysis.The results show that the radial dimension and preload of bolt have influence on the modal distribution and dynamic characteristics of transducer.The frequency of voltage applied to piezoelectric stack affects the ultrasonic energy transmission.The relationship between the quality of bonding balls and the radial dimension of the bolt was studied through wire bonding test.The analysis and experimental results provide instructions for the design of transducer and the optimization of thermosonic bonding process.