Package Level Radio Frequency Interference Shielding Structure Using Via Array

This paper proposes a via array structure that is applicable to package in reducing radio frequency interference (RFI). The via array structure is applied to the redistribution layer (RDL) of the package for shielding purposes. To further validate the effect, the test structure is designed and fabricated using Yagi-Uda antenna and microstrip mitred bend (MMB) transmission line. The coupling between the transmission line and embedded antenna is investigated to determine the strongest noise coupling point, and via array structures are placed at those points. By applying the proposed via array structure, the measured coupling noise between the transmission line and the receiver antenna is reduced up to 12 dB.