Highly strength Cu-Cu joint formation by sintering of copper nanomaterials

Solder paste used in wide bandgap semiconductor devices are facing severe challenges for the working characteristics of high power, high temperature and high voltage. In this paper proposes a method for preparing anti-oxidation copper nanoparticles material, which copper acetate is used as precursor, ascorbic acid is used as a reducing agent, PVP and 2-phenylimidazole are used as protective agents, and copper nanoparticles powder with oxidation resistance at room temperature is prepared.The size of copper nanoparticles can be controlled between 50nm and 200nm. Through XRD testing, it was found that the copper nanoparticles powder can be stored in a normal temperature air environment for one month without being oxidized.The TG test found that the weight of copper nanoparticles powder increased only 4.52% when heated to 600 C, and the copper nanoparticles powder prepared using PVP alone increased 12.86%. Through shear tests, it was found that the copper-copper nanoparticles layer-copper structural parts sintered in 300 C temperature and 5MPa pressure showed shear strength of 59.79MPa, which is nearly 86% higher than that of copper nanoparticles powder prepared with PVP alone.