Study of die attach technologies for high temperature power electronics: Silver sintering and gold–germanium alloy

• We compare 3 die-attach technologies for high temperature power electronics packaging.
• Micro and nano silver sintering processes and AuGe solder alloy process are presented.
• After high thermal ageing test, the results showed very high die shear strenght capability.
• No evolution of the AuGe solder alloy joint is observed after 2500 thermal shocks cycles.
• High range of temperature was used for the ageing test (-55°C to +245°C).

Silver sintering joints and AuGe soldering are promising technologies for high temperature (>200 °C ambient) power electronics packaging. This paper presents the implementation of two silver-sintering processes with the one hand micrometer-scale silver particles, and on the other hand nano-meter-scale particles. Two substrates technologies have been investigated: A12O3 DBC and Si3N4 AMB. After the process optimization, tests vehicles have been assembled using both sintering processes, as well as a more classical high-temperature die attach technology: AuGe soldering. Multiple analyses have been performed, such as thermal resistance measurement, shear tests and micro-sections to follow the evolution of the joint during thermal cycling and high-temperature storage ageing.