High-Speed Interconnect Transmission Structure Design and Optimization in 3D Integrated System

In this paper, a novel vertical interconnect transmission structure working at 0.1-20 GHz frequency is proposed. During the fabrication process of the package, the manufacturing of vertical interconnect structures is often limited by the process. To address signal integrity and impedance matching between the transmission lines and vertical interconnect structures, a vertical transition structure from microstrip line to coplanar waveguide is proposed. The proposed transmission structure model consists of two signal through-silicon-vias (TSVs), two microstrip coplanar waveguide transmission lines and one pad. The simulation result of the finite element model of this proposed transmission structure shows that the return loss (S11) is less than -30 dB and the overall insertion loss (S21) is greater than -0.2 dB, which means low loss high-speed vertical interconnect transmission structure design is possible by carefully design the vertical interconnect structure. By optimizing key parameters such as the pad radius, the width of the coplanar waveguide transmission line and the substrate material, the transmission performance of this vertical interconnect structure is enhanced and the structure meets the requirements of modern manufacturing processes. This proposed vertical interconnect structure design rule gives a good reference of how to meet the high-speed vertical transmission demand under the mature process technology.