Low-Temperature-Sintered Nano-Ag Film for Power Electronics Packaging

Nano-Ag paste sintering has attracted much attention for high-power electronics packaging owing to its excellent electrical conductivity, thermal conductivity, and oxidation resistance. However, it requires printing and pre-heating before the die attach process, and the organics in the paste do not evaporate easily for large-area die attachment. In this work, a nano-Ag film (~ 100 μm thickness) with only 2.1% organics is developed to realize low-temperature bonding, which is compatible with the current sintering bonding process. The optimized preparation parameters of the nano-Ag films was optimized as 180°C-5 min. The characteristics and sintering mechanism of nano-Ag film are discussed. The results showed that the micro/nanostructure on the surface of nano-Ag film with a small amount of organic material is responsible for the low-temperature sintering ability, which realized 24.01 MPa shear strength at 200°C. The fracture was analyzed and failure modes are discussed. The easy-to-use features and low-temperature sintering ability make the nano-Ag film a promising die-attach material with high reliability. Graphical Abstract: [Figure not available: see fulltext.]