Novel Low-Loss Shielded Interconnects for D-Band/Sub-THz Applications Using Microscale Metal Printing Technologies

This work presents the first demonstration of a shielded interconnect geometry enabled by a novel metal microadditive manufacturing (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>AM) process. The printed interconnect operates at the D band (110–170 GHz) and features an innovative helical-shaped geometry that resembles the ideal transmission performance of a microscale coaxial cable, significantly reducing the impedance mismatch losses that are typically observed in conventional wirebonding interconnects when utilized beyond 100 GHz. The measurements demonstrate superior and reliable performance at least up to 155 GHz with an insertion loss (IL) below 1.5 dB and an RL greater than 10 dB. The proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>AM-enabled interconnect has the potential to pave the way for the next generation of heterogeneous packaging solutions targeted for sub-terahertz (THz) applications that require robust and broadband performance.