Over 10 GHz equivalent circuit model of ACF flip-chip interconnect using Ni-filled ball and Au-coated polymer balls

In this paper, we firstly present the equivalent circuit model of an anisotropic conductive film (ACF) flip-chip interconnect using Ni-filled balls and Au-coated polymer balls. The models were extracted up to the microwave frequency region over 10 GHz. The extracted model parameters of the Ni-filled ball interconnect are compared to those of the Au-coated polymer ball interconnect with respect to impedance and resonance frequency. The ACF using the Ni-filled ball can be manufactured with reduced manufacturing cost and a simplified process, while it still has comparable electrical performance to that of the Au-coated polymer ball. Thus far, the Au-coated ball interconnect has been most widely used. S-parameter measurements and subsequent microwave network analysis were used for the extraction procedure for the impedance parameters