Towards high temperature electronic modules in which all components would be attached using silver sintering
Résumé
This article points out the fact that conventional low temperature silver sintering processes do not seem to satisfy the needs for reliability when they are used to assemble passive components (such as multilayers ceramic capacitors) in electronic modules undergoing wide amplitude thermal cycles (−65°C / +200°C). These processes indeed lead to very porous microstructures of silver which favors rapid fatigue cracks propagation [1], [2], [3]. Even if these types of porous microstructures may be suitable for die attach, tests presented in this paper show they cannot resist to the levels of thermomechanical stress reached in attachment joints of multilayers ceramic capacitors (MLCCs). To find process parameters minimizing porosity in attachment joints of capacitors, measurements of the shrinkage of silver during sintering have been carried out by dilatometry. Then the impact of densification of attachment joints on the ageing behavior and on the mechanical behavior of assemblies has been assessed in this study.