Effect of wirebond geometry and die setting on wire sweep

Abstract

An effective and convenient method is presented for describing wirebond geometry. The method employs a minimum number of geometric parameters which are directly related to the IC package design. Computational simulation of wirebond behavior with in-plane flow load is carried out. A 2-D creep flow model is used to predict the velocity distribution and the flow load acting on the wirebond. A finite element method, which allows for plastic deformation and large deflection, is used to predict the deformation of and stress distribution in the wirebond. Comparative analyses of wirebond behavior with different die settings and loop profiles are carried out. The buckling of wirebonds with in-plane flow load is also studied. Very interesting results have been obtained. The numerical results will be useful for the optimal design of IC packages.