Low Temperature Sintering Mechanism of MOD-Assisted Ag Paste for Power Electronics: Experiment and Molecular Dynamic Study

Abstract

This study investigates the low-temperature sintering of micro-silver pastes enhanced with metal organic decomposition (MOD) additives including propylamine, octylamine and 1,2-propylenediamine, focusing on their thermal properties, decomposition mechanisms, and sintering behaviors. The results show that all MOD additives decompose below 200°C, making them suitable for low-temperature sintering. Among them, the propylamine-based MOD (MOD 1) performs the best by yielding smaller silver particles (105.34 nm) with minimal residue. Molecular dynamics (MD) simulations reveal that MOD 1 decomposes by releasing gases (H₂, CH₄, C₂H₄) and forming silver complexes, which promotes the silver particle aggregation and Ag-C bond formation. Additionally, four types of silver particles in spherical and flaky forms were further studied. It was found that flaky micro-sized particles exhibited better sintering performance than spherical submicron particles with reduced porosity, lower resistivity, and higher shear strength. These findings highlight the superior performance of MOD 1 in enhancing its sintering properties of silver pastes, showing great potential in the low-temperature sintering for power electronics.

Keywords: Power Electronics, MOD Additives, Low Temperature Sintering, Micro-Ag Paste