Investigation of properties of the SAC solder paste with the silver nanoparticle and carbon nanotube additives and the nano solder joints

Several nanomaterials like silver nanoparticles and carbon nanotubes were obtained and their size and microstructure were investigated. The silver nanoparticles were characterized by different grain size (from below 10 nm up to 200 nm) and microstructure. The diameter of the carbon nanotubes was 5 ÷ 50 nm and the length 0.5 ÷10 µm (max 100 µm). These nanomaterials were mixed with our own prepared SAC solder paste. Several technological properties of the “nano” solder pastes were investigated like spreading, wetting, solder ball and slump. The “nano” solder pastes were used for soldering on Cu substrates. Some mechanical properties of the “nano” solder joints were also investigated. Microstructure of the “nano” solder joints were carried out using SEM equipped with energy dispersive X-ray spectroscopy (EDS) system. Relation between properties of the solder joints with nano particles and their microstructure was analyzed.