Relaxation of Solid–State Bonding Conditions of Cu Using Formate–Coated Cu Nanoparticles

Abstract

To examine the effect of bond strength at the Cu/Cu bonded joint interface of formate coated Cu nanoparticles, the interfacial microstructures and fractured surfaces of joint were observed using SEM. Cu nanoparticles surface was modified by immerse to room temperature formic acid for predetermined time. Bonding process was performed at bonding temperature of 523〜723 K under a load of 20 MPa (bonding time of 15 min). By applying the metal salt coating treatment, a good bonding interface with fewer voids was obtained compared to the case without treatment. From the experimental results, it is found out that formate coating process is effective at removing oxide film and substitution to a metal salt on the Cu nanoparticles surface.