Power modules die attach: A comprehensive evolution of the nanosilver sintering physical properties versus its porosity
Résumé
Along with the need to drastically limit the emission of greenhouse gases, the increase of electric or hybrid solutions in the market mostly relies on their dependability with a specific focus on reliability of the embedded power electronics. Due to RoHS restrictions, conventional lead-based solders cannot be used anymore. Sintered nanometric silver paste was chosen as an alternative candidate because of its high melting point, its promising behavior under aging, its better thermal and electrical conductivities and its low sensitivity to oxidation. However, few data are available in the literature concerning its mechanical properties. The processing route, based on the sintering of nanocrystalline powder, provides a material with significant porosity that is known to modify the mechanical properties when compared to the dense material. In this work, the identification of the porosity rate of such material after sintering process is investigated and hence the reliability of silver sintering depending on porosity rate is also analyzed.