Bondwire Integration Challenges in E-band Systems: from PCB to Die Level

In this paper, an approach toward impedance compensation of die to printed circuit board interconnected via bondwire is presented. A use-case is illustrated where a standard millimeter-wave bondwire interconnects between a 50-Ohm microstrip transmission line realized on top of an alumina substrate and a 50-Ohm grounded coplanar waveguide to WR12 rectangular waveguide transition. Direct interconnection showed in both simulation and measurements a 17% reduction in operational bandwidth. Furthermore, asymmetric fabrication of the bondwires caused reflection discrepancy. The proposed solution employs a T-shaped power divider technique which is compared to the classical quarter-wavelength transformer throughout this study. Theoretical modelling and simulationbased sensitivity analyses are presented for both techniques. The proposed technique, which employ two bondwires, proved to be robust and less sensitive to fabrication errors. Thus, restore the bandwidth and show better reflection.