Mechanical Reliability of Cu Particle-Containing Sintered Ag Die Bonded Structure

Low-temperature bonding and high heat-resistant Ag sintering technologies have attracted attention for SiC power device packaging. In particular, the development of Cu-containing composite high-temperature bonding materials has been actively pursued. However, one of the significant challenges is the deterioration of mechanical reliability and thermal dissipation due to crack formation in the bonding layer caused by thermal stresses during thermal cycling. In this study, we fabricated multilayer bonded structures by stacking Ag layers with desired thickness ratios, using both Cu particle-containing sintered Ag die bonded structures and conventional sintered Ag die bonded structures. A comparison was conducted between multilayer die-bonded structure and conventional single-layer die-bonded structure in terms of crack propagation and delamination area. The results demonstrated that multilayer die-bonded structures exhibited improved bonding quality compared to single-layer die-bonded structures, suggesting the potential of this approach for enhancing power device packaging reliability.