Atomistic study of shearing mechanism of nano-Ag joints and processing parameter optimization

Abstract

The exploration of wide band gap semiconductors (WBGs), notably silicon carbide (SiC) and gallium nitride (GaN), has significantly advanced their applications in high-performance electronics due to their ability to operate at high temperatures and high voltages. However, the reliability of traditional interconnection materials, such as tin-based solders, diminishes under these high-temperature conditions, necessitating the development of new interconnection materials. This study focuses on the atomistic mechanisms underlying the shearing process of nano-silver (Ag) joints and the optimization of their sintering parameters to enhance performance. Through molecular dynamics (MD) simulations, we have investigated the microstructural evolution during shear, highlighting the critical roles of dislocation dynamics and crystal transformations. The simulations have informed the design of sintering processes, which were subsequently validated through experimental thermal compression of micro-Ag paste. Our results indicate that sintering at 280 ℃ for 7 min under 8 MPa maximizes shear strength, achieving a significant improvement from 23.84 MPa to 44.49 MPa. These findings contribute to the development of robust and reliable Ag joints for advanced technological applications, offering valuable insights into optimizing sintering processes to enhance material performance.