Thermo-mechanical reliability of nanosilver sintered joints for large-area bonding

Abstract:
This paper investigates the thermal mechanical reliability of sintered joints for large area sintering (39 mm × 39 mm). Two Si3N4-based substrates were sintered togeher using nanosilver paste under either pressure-assisted sintering or pressureless sintering. The thermo-mechanical reliability of sintered samples was evaluated using thermal cycling test with a temperature swing of -55 to 170 °C. The microstructural evolution was monitored by using nondestructive X-ray computed tomography at regular thermal cyclic intervals. The results indicate sintered joints with good adhesion integration and uniform microstructures can be obtained using pressure assisted sintering, while a porous structure predominantly at the edge of sintered joints is evident using pressureless sintering. However, there is no significant microstructural degradation detected up to 2800 cycles, in the sintered joints, irrespective of whether pressure was applied or not during sintering.