Copper nanoparticle paste on different metallic substrates for low temperature bonded interconnection

Even though tin-based lead-free solder is now commonly used in the electronics industry, new materials are still being investigated for superior properties such as metallic nanoparticles. In this study, we evaluate our recently developed copper nanoparticles paste (nano Cu) as a joining material between metallized component and metallized substrate. The size of our copper nanoparticles allows bonding to occur at a low temperature compatible with electronics devices. We studied the electrical and mechanical properties of the bonded component and substrate with different metallized surfaces such as Cu or Au. Good bonds can be achieved with Au surfaces while for Cu surfaces, acid pre-cleaning is required to improve the bond strength between nanoCu paste and Cu surface due to native oxide.