Conductive fillers made from metal nanoparticles offer many advan-tages for the fabrication of a variety of electronic devices,but when they have a porous structure,their poor conductivity limits their adoption in man...Conductive fillers made from metal nanoparticles offer many advan-tages for the fabrication of a variety of electronic devices,but when they have a porous structure,their poor conductivity limits their adoption in many applications.In this study,an Ag-coated Cu micro-nanoparticle paste is used to achieve compact filling of blind vias on flexible copper clad polyimide laminates through a multistep filling and sintering tech-nique.The filled blind vias achieve a resistivity as low as 6.2μΩ·cm,which is comparable that of electroplated blind vias.Higher sintering pressure and temperature promote the filling performance,while the conductivity deteriorates at a via depth/diameter ratio greater than 1:1.Finite element simulations reveal a stress inhomogeneity in vias with large depth/diameter ratios,which is the key to understanding the evolution of the conductive properties of a paste-filled via.This study provides an effective method for high-performance microvia filling as well as insights into the mechanism that influences its performance.展开更多
基金This work was supported by the National Key R&D Program of China(2018YFE0204601),the National Natural Science Foundation of China[61874155,62174039]Key-area Research and Development Program of Guangdong Province[2021B0101290001,2020B0101290001]+1 种基金Open Project of the State Key Laboratory of Advanced Materials and Electronic Components[FHR-JS-202011005]Guangdong Basic and Applied Basic Research[2021A1515011642,2021A1515110656,2022A1515010141].
文摘Conductive fillers made from metal nanoparticles offer many advan-tages for the fabrication of a variety of electronic devices,but when they have a porous structure,their poor conductivity limits their adoption in many applications.In this study,an Ag-coated Cu micro-nanoparticle paste is used to achieve compact filling of blind vias on flexible copper clad polyimide laminates through a multistep filling and sintering tech-nique.The filled blind vias achieve a resistivity as low as 6.2μΩ·cm,which is comparable that of electroplated blind vias.Higher sintering pressure and temperature promote the filling performance,while the conductivity deteriorates at a via depth/diameter ratio greater than 1:1.Finite element simulations reveal a stress inhomogeneity in vias with large depth/diameter ratios,which is the key to understanding the evolution of the conductive properties of a paste-filled via.This study provides an effective method for high-performance microvia filling as well as insights into the mechanism that influences its performance.
