芯片键合换能系统中接触界面的影响分析

接触界面对超声能量传递与振动特性的影响是各类压电换能器的共性问题。在超声芯片封装领域,各子部分之间的接触界面是影响系统超声能量传递的强非线性因素,直接影响芯片与基板的键合质量。该文通过有限元法与激光多谱勒测振仪等技术,获得系统中接触界面对超声能量传递与振动特性的影响规律,发现不合理的接触界面会引发系统多模态与频率混叠效应、超声能量输出不稳定、系统迟滞响应等,导致键合强度下降、芯片与基板倾斜、键合效率下降等封装缺陷。研究结果对理解超声键合与系统设计具有指导意义。

Effect of Contact Interface on Transducer System on Thermosonic Bonding

The effect of contact interface on ultrasonic energy propagation and vibration properties and vibration properties is the common problem of all kinds of ultrasonic transducer.In thermosonic bonding,contact interfaces between different parts are nonlinear factors,which affect directly the ultrasonic energy propagation and bonding quality.By using finite element method and laser Doppler vibrometer,the effect of contact interface on the ultrasonic energy and vibration are investigated.It is found that incorrect contact interfaces cause multiple vibration modals and mix certain resonance frequencies,inducing non-stable output of the ultrasonic energy,and leading to hysteresis response.All these would cause some bonding shortcomings such as lower bonding strengths and chip tilting.The researches result help to understand the bonding process and transducer design.