Compact 5G N77 bandpass filter design mixing IPD and MIS technologies

This paper presents a compact and selective passive bandpass filter for 5G n77 application, using a flip chip integrated passive device (IPD) mounted onto a molded interconnect substrate (MIS). Passive elements integration has been distributed on each technology in order to enhance filter selectivity. The IPD mostly integrates high Q factor capacitors, and inductors are distributed on both IPD and MIS. Flip chip approach has been used to reduce the filter size, to benefit from 3D integration using vertical coupling between IPD and MIS. The MIS also plays the role of I/O redistribution to align final product footprint with standard filters. IPD capacitors are protected from electrostatic discharge (ESD) thanks to the overall filter architecture. The filter is mounted onto a dedicated on-wafer pattern and measured with RF probes. The size of the filter is 2mm x 1.25mm.