Filler size influence on moldabilty of high density QFN package

Abstract

In today semiconductor's market, in order to fulfill the requirements of the growing mobile GPS market for higher sensitivity, higher immunity against interference of cellular signals and low power consumption, the new QFN package named TSNP 11-2 had being developed as the world's smallest GPS Receive Front End module. The package size measures just 2.5mm × 2.5mm × 0.7mm in size with one Low Noise Amplifier (LNA), filters chip and a diode in this tiny package. Nevertheless, it comes with challenge on wire loop height due to stack die, narrow half etch design due to thin lead frame and thin package thickness (wire to top package cavity). Different filler size couple with different spiral flow had been evaluated to understand the influence on moldability. From the study, filler size plays an important or dominant role in resolving the moldability issue by total eliminating of wire sweep. Thus help in improving the production yield by 8%.