Sintering of Silver–Aluminum Nanopaste With Varying Aluminum Weight Percent for Use as a High-Temperature Die-Attach Material

A new Ag-Al nanopaste die-attach system for high-temperature use is introduced for the first time in this paper. The Ag-Al nanopaste with varying Al nanoparticle weight percent (wt%) is sintered at 380^°C for 30 min. The effects of organic burn-off from the nanopaste in aiding solid-state fusion between the Ag and Al nanoparticles are investigated. The formation of Ag₂Al and Ag₃Al is detected in post-sintered nanopaste layers. Thermal and electrical conductivity measurements are also conducted to understand the properties of the post-sintered Ag-Al die-attach material in relation to increasing Al content. Thermal expansion analysis is performed to gauge the expansion of the post-sintered Ag-Al nanopaste against other high-temperature packaging components, as it is critical to avoid thermal stresses during device operation.