MCM-D/L technology for realization of low cost system-on-package concept at 60-80 GHz

This paper proposes a low-cost extension of the RF System-on-Package (SoP) concept including antenna arrays up to 60-80 GHz frequencies. The solution is based on a new modified 3-layer 15 μm BCB-based MCM-D or MCM-D/L technology set. The carrier set for MCM-D includes aluminium, low-resistivity silicon and ROGERS 4003 substrates. The MCM-D/L version is supported by different material thin laminated films including a new developed liquid crystals such as BIAC LCP. This mixed solution allows the realization of patch antennas with efficiency of up to 80% at 80 GHz. The NiCr resistors can be integrated directly on the substrate or on the top layer depending on the application. A Ta₂O₅ layer is also included for the realization of decoupling and higher value microwave capacitors. Both microstrip and CPW approach for the realisation of transmission media and distributed passives are possible depending on the substrate carrier. We point at the microstrip lines as compacter and outperforming solution by the use of our technology set. The paper is focused only on the integration of the distributed passives in microstrip configuration at 60 GHz on MCM-D version with aluminium carrier. We present some first run measurement results based on Wilkinson power divider, balun, band-pass filter and branch-line coupler. The designed elements show very good performance and agreement with the full-wave simulations. The investigations presented are within the framework of the European LIPS project ("Low Cost Interconnect, Packaging and Subsystem Integration Technologies for Millimetre-Wave Applications").