Study on the Interconnect Performance of Multicomponent paste for 3rd Generation Semiconductor Packaging

Nowadays, due to the size effect of nano materials, nano silver, nano copper and other nano materials were widely used in the low-temperature packaging and interconnection of electronics. In order to solve the problems of electromigration and high price of nano-silver in electronic packaging. This paper proposes to use low-cost micro-nano mixed copper powder as the main body, and doped with micrometer and nano-silver powder, combined with the characteristics of nanoparticles with large specific surface energy and the good stability of micron particles to obtain a multicomponent paste with higher density, higher conductivity and lower cost. The effect of the relative size and mixing proportion of nano-sized copper and silver on its sintering performance was investigated. The micro-nano copper-silver particles were mixed in different proportions to prepare a micro-nano copper-silver metal paste and sintered by hot pressing. It was found that the shear strength can reach 27.2MPa when 1μm Cu powder and 60nm Ag powder were mixed at 1:1, which was much higher than the shear strength of 9.3MPa when 60nm pure Ag powder was separately sintered. When 100nm Cu and 60nm Ag were mixed at 1:1, the shear strength after sintering was 5MPa. The results showed that the interconnection strength of the electronic package can be significantly improved by the micro-nano copper-silver paste compared with the single size paste. Micro-nano mixed paste had better shear strength. Between the micrometer particles, because the nano particles filled the pores of the micro particles, the micro-nano mixed paste with high density can be formed, which was beneficial for improving sintering performance.