Swing Touch Risk Assessment of Bonding Wires in High-Density Package Under Mechanical Shock Condition

Abstract

Long bonding wires may swing significantly and touch with adjacent ones, which will result in short circuit under mechanical condition, especially in aerospace applications. This may seriously affect the operational reliability of high-density hermetic package components. The aim of this paper is to assess the touch risk of high-density package component under mechanical shock condition. An experiment setup, which can obtain the touch critical load and detect the wires swing touch through voltage signal captured by oscilloscope, is designed and built. To obtain the vibration data of different bonding wire structures under different shock loads, numerical simulation models are established after verified by the experimental data. Additionally, initial swing amplitude model, vibration frequency model, and damped coefficient model are established based on the simulation and experiment data. Furthermore, wire swing touch risk assessment model is established in consideration of the distribution of wire structure and shock load deviation. Based on the verified numerical simulation model, vibration characteristic parameters, including the initial swing amplitude, vibration frequency, and damped coefficient, can be calculated by numerical simulation and experimental results. The proposed method can be used to assess bonding wire touch risk in high-density hermetic package quantitatively. Potential touch risk, which cannot be reflected by failure analysis of structure damage after test, can also be detected by the electronic measurement designed in this paper. The proposed method can effectively reflect short circuit between long bonding wires of hermetic package in large shock applications, such as transport and launch.