In-Situ Analysis of Crack Propagation in Wire Bonds Causing Intermittent Failures in Electronic Systems with Liquid-Nitrogen Thermal Shock Testing

Abstract

Intermittent faults in electronic systems can cause catastrophic failures in mission-critical applications. However, because of the dynamic nature of intermittent faults, most of the errors disappear before they can be analyzed, complicating the identification and resolution of their root cause. In this study, we perform in-situ analysis of intermittent wire-bond defects observed in a complementary metal-oxide semiconductor buffer, to investigate their root cause. The waveform distortions representing various stages of an intermittent wire-bond defect are successfully captured by applying a liquid-nitrogen thermal shock that induces crack propagation because of the mismatched coefficients of thermal expansion. Simulation program with integrated circuit emphasis software is utilized for waveform analysis, and the propagation of nanoscale cracks is analyzed geometrically using a high-frequency structure simulator. Resistance levels ranging from several hundreds of ohms to kilo ohms and crack-induced capacitances up to 10 pF are observed, with the DC resistance contributing significantly to system errors. Moreover, we demonstrate electrical recovery through crack closures resulting from the thermal shock. The combination of crack propagation and closure is determined to be the root cause of intermittent failures. The analysis of wire-bond–defect characteristics, buffer architecture, and measured wire-bond–defect waveforms can help determine the location of the defect. Our results provide new insights into the propagation and recovery mechanisms of wire-bond cracks.