Nano silver particles prepared by spark ablation as packaging interconnection material

With the increasing requirements of the electronic industry for the performance of packaging and interconnection materials, it is the driving force for the use of metal nanoparticles as chip interconnection materials in the field of microelectronics. Due to the small size effect, metal nanomaterials have the characteristics of “low temperature sintering, high temperature service”, and are considered as a good substitute for tin based solder. High purity and small size metal nanoparticles can be prepared by spark ablation without any chemical reaction. In addition, aerosol lines for gas production are continuous and have the potential to expand production. This method can be used for the preparation of semiconductor, metal, oxide, multicomponent mixed nano materials and alloys. In this paper, the preparation of silver nanoparticles by spark discharge ablation of silver target in inert gas was studied systematically. By adjusting the spark discharge parameters and gas flow rate, dispersed and non agglomerated particles or aggregates with an average size of about 20 nm were prepared. The size distribution, morphology, structure, conductivity and thickness of silver layer were characterized by scanning electron microscope (SEM), four point probe resistance test and profilometer. The experimental results show that the silver nanoparticles produced by high purity gas are very clean and can be sintered at low temperature and low pressure, which can meet the requirements of packaging interconnection performance.