High-frequency SPICE model of anisotropic conductive film flip-chip interconnections based on a genetic algorithm

This paper firstly reports on the high-frequency SPICE model of the ACF fli p-chip interconnections up to 13 GHz. The extraction process Is based on an optimization procedure, called a genetic algorithm, which is known as a ro bust optimization tool. The proposed equivalent circuit model of the ACF in terconnection can readily be used in SPICE circuit simulations for signal i ntegrity analysis of high-frequency packages. Two different ACF interconnec tions were studied using the Au-coated polymer ball and Ni-filled ball. The extracted models of the two ACFs were found strongly dependent on not only size and rigidity of the conducting balls, but also on their magnetic perm eability.