Mitigation of unintentional radiation from the package lid using PMC packaging

Package lid is usually mounted above the integrated circuits (ICs) to protect the die and improve the thermal performance. However, the package lid may be an unintentional radiation contributor due to the resonance of package lid and package substrate. In this paper, based on a typical wire-bonded ball grid array (WB-BGA) package, perfect magnetic conductor (PMC) packaging is used to suppress the electromagnetic interference (EMI) radiation caused by the package lid. Lid of nails (also called pin surface) is utilized to realize the PMC condition within a certain frequency range. The simulation results confirm that the lid of nails can effectively reduce the radiated emission from the lid in the frequency range as designed.