A novel RDL structure of improving high-frequency transmission and reliability of FOWLP

Abstract

In this paper, an effective structure RDL-GR is proposed to improve the electrical and reliability of the fan-out wafer package (FOWLP) with the addition of a graphene layer on the surface of the Redistribution Layer (RDL), including suppression and modulation of signal delay and crosstalk noise. A modified circuit model is formulated to evaluate the impact of RDL-GR on the transmission characteristics at high frequencies. Subsequently, the validity of the model is verified by utilizing the HFSS. Found on the circuit at high frequencies, the transmission characteristics of the RDL-GR compared to the traditional RDL structure (Tr-RDL) have better performance. At the same time, measurement by Vector Network Analyser (VNA) is carried out and results prove that the maximum error values of S11 and S21 are 1.81% and 1.47%, and make a strong case that S-parameters of RDL-GR for simulation using HFSS are reliable.