A novel bonding process using Ag2O paste composed of Ag2O particles and a reducing agent has been proposed as a Pb-free alternative of high melting point solders in electronics packaging. Ag2O paste formed Ag nanoparticles through the redox reaction in the bonding process and in-situ formed Ag nanoparticles sintered immediately. While the bonding process using Ag metallo-organic nanoparticles, which have been proposed, was unfavorable to the bonding at 250 degree Celsius or lower in terms of requiring removal of stable organic shells, the bonding process using Ag2O paste demonstrated the possibility of further low-temperature bonding.
Bondability under lower applied pressures (0.5 and 1 MPa) was investigated on the basis of the interaction force generated between the particles and the solvent used during sintering. In the case of single (unmixed) solvents, the shear strength decreased monotonously with an increase in the molecular weight of the solvent used, regardless of the size of the particles used. This was because the decomposition of solvents with high molecular weight was not complete till bonding at 300°C. In the case of mixed solvents, the shear strength achieved using a mix of triethylene glycolol (TEG) and polyethylene glycol (PEG) 200 increased and was greater than that achieved using conventional solders. The results obtained could be explained well by the dynamics of the solvent and the particles. Thus, it was surmised that the capillary force can be effective in joining larger particles together under lower applied pressures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.