Electrical modeling of quad flat no-lead packages for high-frequency IC applications

This paper presents electrical modeling of quad flat no-lead (QFN) packages for high-frequency integrated-circuit (IC) applications. In order to predict effectively the package characteristics, the QFN packages were modeled by three-dimensional electromagnetic numerical simulation according to the physical package structures of the real QFN packages. An analytical method was also used to model the QFN packages and extract the parasitic parameters of the packages, including capacitances, inductances, and resistances. The microwave characteristics of the QFN packages, such as return loss and insertion loss, were studied under open-path and short-path configurations. The S parameters of the QFN packages from the numerical modeling are consistent with those from the analytical modeling at the frequencies up to 15 GHz.