Molding technology development of large QFN packages

Abstract

Encapsulation of large QFN packages (> 5 × 5mm) are quite challenging as compared to normal small QFN packages as the big die pad in leadframe and multiple narrow gaps between leads may caused mold void rejects at the half etch areas. High density of fragile wires is prone to have wire sweep too as the EMC flow impact on longer wire length is significant which can caused wires sweep during mold filling.