Nanoscale Silver Sintering for High-Temperature Packaging of Semiconductor Devices

摘要

Silver nanoparticles were prepared from solution using the Carey Lea method. The silver particles obtained by this method ranged from 10nm to 30nm in diameter. Silver paste was prepared by adding terpineol to the dry silver nanopowder and mixed in a roller mill for up to 48 hours. The paste was stencil-printed on metallized substrates and heated to volatilize the binder and solvents and to sinter the metal particles. Preliminary sintering experiments showed widespread neck formation between particles at temperatures as low as 280℃. Initial die-attach tests also resulted in very strong bonding between device and substrate. This could lead to significantly lower sintering temperatures making it possible to attach both silicon and high-temperature wide-bandgap semiconductor devices using silver instead of solder, which in turn will enhance the electrical, thermal and mechanical performance and reliability of device interconnections. Additional research is ongoing and future research will include improvement in the dispersion of the nanoparticles, characterization of the densification behavior and optimizing die-attach conditions.