High-temperature nanoindentation characterization of sintered nano-copper particles used in high power electronics packaging

Nano-copper sintering is one of new die-attachment and interconnection solutions to realize the wide bandgap semiconductor power electronics packaging with benefits on high temperature, low inductance, thermal resistance cost. Aiming assess high-temperature reliability sintered nano-copper interconnection, this study characterized mechanical properties particles using nanoindentation tests. The results showed that: firstly, hardness indentation modulus increased rapidly when loading rate below 0.2 mN·s−1 then stabilized, decreased applied load up 30 mN. Next, by extracting yield stress strain hardening index, a plastic stress–strain constitutive model at room temperature for was obtained. Finally, tests were performed 140 ˚C–200 ˚C prepared under different assisted pressures, which that pressure resulted in reduced sensitivity modulus. creep indicated operation steady-state rate, negatively impacted particles, while higher could improve resistance.