A PSPI/PSEP/PSPI Nanocomposite Polymer Interposer Technology for Wireless Edge-AI Microsystem Integration

In this paper, we present a five-layer polymer-based interposer technology using inkjet printing to fabricate silver vertical through-substrate vias (TSVs) for beyond 5G and edge-AI applications. Photosensitive epoxy resin (PESP) and polyimide (PSPI) are employed as low-loss dielectric materials, providing excellent thermal and mechanical stability. High-frequency measurements of microstrip line structures demonstrate good performance, with characteristic impedance close to 50 Ω and low insertion loss at 94 GHz. In addition, strong agreement between measurement and simulation results of a 79 GHz substrate-integrated waveguide (SIW) antenna confirms the feasibility of the proposed design. Compared with conventional interposer technologies, this approach offers a lightweight, low-cost, and high-performance solution for advanced heterogeneous integration, particularly in edge-AI sensing and high-frequency communication systems.