Wafer level package of Wideband Microwave Transmission System and Integrated Microwave Antenna using BCB/Metal structure with the die embedded in Si substrate

Abstract

In this paper, a wafer-level package for a microwave transmission system has been implemented and tested. Three Monolithic Microwave Integrated Circuits (MMICs) packaged in one microwave system are first proposed. The packaged system consists of an up-converter, a drive amplifier and a power amplifier. All the modules are embedded in the cavities pre-etched in a low-resistivity silicon (Si) substrate. BCB layers are coated on the components and silicon substrate, serving as interlayer dielectrics (ILDs). Also, a technique for micro-strip patch antenna and folded slot antenna fabricated using BCB as dielectric was presented. The most distinctive feature of this technique is that the antenna is integrated in low resistive silicon wafer and completely compatible with the microwave multi-chip module (MMCM) packaging process. The electrical properties of the packaging structure are investigated. The measured transmission characteristics of the packaged system shows that the modules can work at very wide band, at the range of 6-18GHz (X/Ku band) and its gain agrees well with the theoretical results. The two antennas resonate at 14.9 GHz with 1.59% impedance bandwidth and 15.6 GHz with 14.7% impedance bandwidth, respectively.