A 60GHz LC-VCO module using flip-chip on a laminate substrate

For emerging mm-wave consumer applications such as high data-rate wireless communications at 60GHz and car radar at 76–81GHz, it is important to investigate the impact of module assembly on IC performance. Flip-chip is a promising candidate to meet requirements like low reflections, low insertion loss and low costs for mm-wave applications. This paper addresses the design, modeling and evaluation results of a 60GHz LC-VCO module using flip-chip. The impact of the substrate on on-chip CPW transmission lines and spiral inductors is studied based on the performance of a 60GHz LC-VCO. Since the inductor is part of the VCO resonator, a remarkable 10% increase in oscillation frequency occurs due to the nearby top-metal layer of the substrate. The IC is realized in a 0.25µm SiGe BiCMOS process. The 0.44mm thick substrate offers four copper signal layers.