Print Email Facebook Twitter Microstructural and micromechanical characterization of sintered nano-copper bump for flip-chip heterogeneous integration Title Microstructural and micromechanical characterization of sintered nano-copper bump for flip-chip heterogeneous integration Author Ji, X. (TU Delft Electronic Components, Technology and Materials) Du, L. (TU Delft Electronic Components, Technology and Materials) He, S. (TU Delft Materials and Environment) van Zeijl, H.W. (TU Delft Electronic Components, Technology and Materials) Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials) Date 2023 Abstract Copper nanoparticles (CuNPs) sintering for flip-chip interconnects is a promising solution for 3D and heterogeneous integration to overcome the limitation of solder materials. To this end, we perform the photolithographic stencil printing method to pattern CuNPs, and the form of flip-chip interconnects is completed after CuNPs sintering process. This paper aims to study the effect of sintering processing parameters (time, pressure, temperature) on the mechanical properties of CuNPs bumps when applying the novel method to approach the Cu interconnects. We fabricated seven groups of specimens of sintered CuNPs bumps, built with a diameter of 100 μm and sintered. The nanoindentation tests assessed the mechanical property to get Young's modulus and hardness. Results clarify that Young's modulus is strongly affected by pressure. An suggested combination of parameters (the 25 MPa and 260 °C for 15 min) give the highest modulus of 126 GPa and the hardness of 1.76 GPa. Moreover, the observations by scanning electron microscopy (SEM) reveal the microstructure and porosity evolution versus different processing parameters. Subject Cu sinteringFlip-chipMicromechanical propertiesMicrostructural characterizationNanoindentation To reference this document use: http://resolver.tudelft.nl/uuid:04b789a2-c2f0-484c-9274-e70683bb6fe6 DOI https://doi.org/10.1016/j.microrel.2023.115180 ISSN 0026-2714 Source Microelectronics Reliability, 150 Part of collection Institutional Repository Document type journal article Rights © 2023 X. Ji, L. Du, S. He, H.W. van Zeijl, Kouchi Zhang Files PDF 1_s2.0_S0026271423002809_main.pdf 3.12 MB Close viewer /islandora/object/uuid:04b789a2-c2f0-484c-9274-e70683bb6fe6/datastream/OBJ/view