Reliability of sintered Ag_(80)-Al_(20)die attach nanopaste for high temperature applications on SiC power devices

摘要

The aim of this research work is to present a reliability analysis on the suitability of the Ag_(80)-Al_(20) sintered die attach nanopaste for high temperature applications on SiC power devices. Die back metallization studies pointed out that Ag and Au would be suitable candidates to form a strong bond between the SiC die and Ag_(80)-Al_(20) die attach for high temperature operations. The post-sintered Ag_(80)-Al_(20) die attach revealed a low modulus of elasticity at 9.8 GPa due to the formation of micro-pores during sintering. This also influenced the hardness and stiffness as well at 0.49 GPa and 30354.14 N/m, respectively. The electrical conductivity of the Ag_(80)-Al_(20) die attach material decreased slightly with increasing thermal aging repetitions. As the die attach material aged, it seemed to undergo a reduction in electrical performance, though as shown earlier the structure was still intact. This decomposition was suggested to occur due to the organic-metallic system's composition itself, and the volatility of the residue organics.