Low Processing Temperature of Lead-Free Solder Interconnects [Nanopackaging]

Solder paste is a homogeneous and kinetically stable mixture of solder alloy powder, flux, and vehicle, which is capable of forming metallurgical bonds at a given soldering condition. The thermal properties of tin/silver/copper (SnAgCu) alloy nanoparticles of different sizes were studied by differential scanning calorimetry (DSC). The particle size-dependent melting point and latent heat of fusion were also observed. The nanoparticle pastes completely melted and wetted on the copper surface, and tin/copper intermetallic compounds (IMCs) were formed after the reflow process. These low-melting-point SnAgCu alloy nanoparticles pastes could be used for low processing temperature of lead-free solder interconnect applications.