Reliability analysis of low temperature low pressure Ag-sinter die attach

The amount of heat to be dissipated from power electronics and microprocessors increases more and more. Therefore new interface materials with high electrical and thermal conductivity have to be considered. Silver is one of a few materials which can fulfil these demands. New low temperature, low pressure Ag-Sinter technologies allow it to use Silver as die attach material instead of solder or glue. Even though silver has excellent thermal and electrical properties, thermo-mechanical reliability aspects have to be considered. In this paper the thermo-mechanical reliability of chip-on-board (COB) assemblies for power applications are studied by experiment and simulation. Thereby the main focus is set on the characterization methods and low cycle fatigue failure behaviour of the die-attach material under thermal cycling conditions. Part of the work has been accomplished within the running EU Project "Nanopack".