Twin-induced ultra-high thermal conductivity of sintering Ag nanoparticles for high power density electronic packaging

Rapid pressureless low temperature sintering of Ag nanoparticles for bonding is achieved. Organic shells adsorbing on the surface of Ag nanoparticles to stabilize them are thinned to be a sparse protecting layer. Numerous coherent twin boundaries formed in sintered Ag nanoparticles with a grain size of 21 nm induce ultra-high thermal conductivity (229 W/m·K), which overcomes the intrinsic defect that metals with nano-sized grain generally cause a pronounced decrease in thermal conductivity because of the grain boundary scattering effect.