Low-temperature sintering with nano-silver paste in die-attached interconnection

Traditional materials used in chip-level interconnections are not compatible with the high-temperature operation of wide-bandgap high-power semiconductor devices; therefore, this paper studies sintered nano-silver as a novel interconnect material mounting semiconductor devices onto metallized substrates. A low-temperature sintering process was employed in the preparation of a sintered nano-silver die-attachment. The physical mechanisms in volatilization and burnout of the added organic components employed in nano-silver paste were analyzed primarily by thermal gravimetric analysis (TGA) to obtain a reasonable temperature-controlling profile. The shear strength of sintered nano-silver joints was investigated, and the evolution of microstructure in the nano-silver paste sintering process was observed using a scanning electron microscope (SEM) in this process. The effects of sintering temperature, heating rate, and holding time during the sintering process were analyzed according to the densification mechanism. The microstructural observations and shear strength tests showed that a sintering temperature of 285 degrees C, heating rate Of 10 degrees C/Min, and holding time of 60 min were the best conditions for using this kind of silver paste.