High-temperature-resistant interconnection using nickel nanoparticles

The bonding characteristics of nickel nanoparticles as a new alternative bonding material for high-temperature soldering was considered and a high bonding strength was achieved at a bonding temperature of 300°C. It was also revealed in a bonding experiment using a silicon dummy chip with a deposited aluminum layer that direct bonding to an aluminum electrode was possible. On the other hand, a stress-relaxation structure using a metal film was presented as a new structure for resolving the problem of deteriorating bonding reliability due to thermal stress arising from differences in the coefficient of thermal expansion between the chip and the substrate. A silicon carbide device was assembled using the new bonding method and an operating test was performed to verify normal operation in a high-temperature environment of approximately 300°C.