Characterization of Microstrip Line and SIW on ABF in Glass Interposers for mmWave Applications

This letter presents the first demonstration of microstrip line and substrate integrated waveguide (SIW) on Ajinomoto Build up Film (ABF) in glass interposer technology for $D$ -band (110-170 GHz). The material stack-up consists of $87.5~\mu \text{m}$ thick ABF supported on ABF/glass/ABF. ABF was metallized using semi-additive process (SAP). Conductor backed coplanar waveguide (CBCPW) to microstrip transitions were used to probe the designed structures. Thru-reflect-line (TRL) calibration was used to de-embed the response of microstrip line and SIW. The measured average insertion loss in $D$ -band for microstrip line and SIW is 0.25 and 0.35 dB/mm, respectively. The simulated and measured results are in good agreement. The performance has been compared with interconnects designed on other substrates like liquid crystal polymer (LCP), high-resistivity silicon, and ABF/glass/ABF stack up. This work can be useful for the development of mmWave for next-generation communication systems.