On the influence of the porosity and homogeneity of sintered die-attach layers on the power cycling performance

Silver sintering is the state-of-the-art technology for highly reliable chip- substrate interconnects. The power cycling reliability, however, strongly depends on the thermal and mechanical properties of the sintered bond line, both of which are governed by the magnitude and the homogeneity of the porosity in the sintered layer. This dependency is investigated and discussed in this paper. Power cycling tests were performed on sintered samples having different porosities and/or porosity distributions after which the samples were subjected to failure analysis. It is concluded that- within the tested ranges- the sinter layer porosity and its distribution is not limiting the power cycling capability.