Synthesis of highly antioxidant and low-temperature sintering Cu-Ag core–shell submicro-particles for high-power density electronic packaging

The highly antioxidant Cu-Ag core–shell submicro-particles ([email protected] particles) were synthesized by "two steps" including replacement reaction and chemical reduction deposition. The Cu submicro-particles with fine size and dispersion were purchased as cores. Glycol was used as reaction solvent and acted as the reductant at high temperature. The results indicate that [email protected] particles with complete, uniform and dense Ag-shells (about 100 nm thickness) were synthesized successfully during reaction at 90℃ for 40 min and 150℃ for 20 min subsequently, with formic acid added. What's more, the nanostructure on surface of the Ag-shell made the low-temperature sintering possible. Finally, Cu-Cu joints with high shear strength of 97.86 MPa were obtained with [email protected] particles by pressure sintering (250℃ for 15 min under 10 MPa) in atmosphere.