Interface enhancing strategy for low-temperature bonding of Ag-based nanoalloy.

• A sandwich structure nanoparticle film is developed for power electronic packaging. • The Ag transition layer provides further driving force for nanoalloy sintering. • The enhancing strategy enables nanoalloy a high reliability die attach material. Bonding interface quality is crucial for power electronic packaging, while the alloyed Ag nanoparticle sintered joint has lower crack resistance at the interface. In this work, a sandwich structure nanoparticle film consisting of an Ag transition layer, nanoalloy layer, and Ag transition layer was developed for interface-enhanced low-temperature bonding. The optimized sandwich structure increased the shear strength of Ag-based nanoalloy sintered joints, reaching 5.6 times for Ag10Cu and 2.0 times for Ag10Pd, respectively. The low-temperature spreadability of the Ag transition layer provided a micro-nano structure and further driving force for nanoalloy sintering on the substrate. Both experimental and molecular dynamics simulation results revealed that these nanoalloy particles spread easier and realized a higher effective bonding area. This interface-enhancing strategy enables the Ag-based nanoalloy a high-reliability die-attach material with low-temperature bondability. [ABSTRACT FROM AUTHOR]