Embedded wafer level ball grid array (eWLB) technology for millimeter-wave applications

Abstract

The embedded wafer level ball grid array (eWLB) is a novel packaging technology that shows excellent performance for millimeter-wave (mm-wave) applications. We present simulation and measurement results of single-ended and differential transmission lines realized using the thin-film redistribution layers (RDL) of an eWLB. We demonstrate the capabilities for the integration of passives on example of a configurable 17/18 GHz down-converter circuit realized in silicon-germanium (SiGe) technology with a fan-in eWLB differential inductor used for the LC tank. We compare the performance of differential chip-package-board transitions realized in an eWLB and in other common package types. We report an optimized compact chip-package-board transition in the eWLB. We obtain a simulated insertion loss as low as -0.65 dB and a return loss below -16 dB at 77 GHz without external matching networks. We introduce the concept of antenna integration in the eWLB and show examples of single-ended and differential antenna structures. Finally, we present for the first time a single-chip four-channel 77 GHz transceiver in SiGe integrated in the eWLB package together with four dipole antennas. The presented examples demonstrate that the eWLB technology is an attractive candidate for mm-wave applications including system-in-package (SiP).