Reducing substrate noise coupling in a 3D-PICS integrated passive device by localized P+ guard rings

This paper presents an original concept of a P+ guard ring realized in a 300µm depth High Resistivity Silicon Substrate (HRS) in order to reduce the substrate noise coupling in a 3D-PICS Integrated Passive Device technology. Guard rings have been designed to be a reliable and efficient protection against noise signals propagation. Case study presented in this work illustrates its significant role. In this paper, a 3D-PICS IPD test chip was studied as a first passive part prototype of a System-In-Package chip in combination with RF transceiver operating in the ISM band (863–870 MHz). Various configurations of the passive chip layout (including implementation of guard rings) have been characterized by Direct Power Injection. 3D-PICS electrical performances deduced from two-ports S-parameters are reported, as well as the guard rings efficiency measurements extracted from these S-parameters. Coupling isolation performances of the new integrated PICS components are found satisfactory.