Bare copper bonding with facilely synthesized Ag nanoparticles decorated Cu microparticles paste

The accelerated application research of power electronic devices intensively stimulates the interconnect materials to catch the ability of low-temperature sintering and high-temperature service. Herein, the uniform micro/nano-hybrid structure particles, which are Ag nanoparticles decorated on the surface of Cu microparticles (Cu MPs@Ag NPs), are fabricated by a mild one-step liquid-phase reduction method. XRD and TG analysis results demonstrate Cu MPs@Ag NPs obtain better anti-oxidation than Cu MPs, which is caused by the decorated Ag NPs. Meanwhile, bare Cu-Cu bonding with Cu MPs@Ag NPs paste is achieved at 200 °C, 250 °C, and 300 °C in the air. The average strength of the Cu–Cu joint reached 29.6 MPa at 300 ℃. Additionally, it is found that the fracture mode of the Cu–Cu joint changes from brittle fracture to ductile fracture when the sintering temperatures increase. This work demonstrates the facilely synthesized micro/nano-hybrid structure particles (Cu MPs@Ag NPs) possess the potential application in high-power density electronic packaging.