Investigation Of EMI Radiation In IC Package

As the operating frequency of modern high-speed electronic devices increases rapidly,electromagnetic interference(EMI)issues,such as unintentional radiation to the surrounding environment and coupling to devices nearby,are becoming one of the technical bottlenecks for next-generation electronic products.Package which connect intergrated circuits to external devices plays an increasingly important role in EMI design.In this paper,based on the typical package technologies,the potential risk items which cause the EMI emission preblems are investigated,and corresponding solutions are proposed.Conventional package lid induces additional EMI radiation due to the resonances between the conventional metal lid and ground plane on package board.In this paper,a novel package lid is proposed based on the gap waveguide theory,which adopts mushroom-type electromagnetic;bandgap(EBG)structures to mitigate the increased EMI emission.In addition,a scalable equivalent circuit model is presented as an assistance for designing the proposed package lid.Both the simulation and measurement results confirm that the proposed lid can significantly reduce the unintentional radiation within the specific frequency range as designed.Based on the commercial wire-bonded ball grid array package(WB-BGA)technology,the potential risk items which cause the EMI emission preblems are investigated,and corresponding solutions are proposed.Package lid,bonding wires and grounding vias are found to be the potentional contributors of EMI emissions for WB-BGA package.Then,some practical solutions are discussed to mitigate the EMI emission,including a novel package lid with mushroom-type EBG structures,lid of nalis,resistive vias and grounding the package lid.In particular,the proposed package lid using EBG structures can mitigate EMI emission significantly in the designed frequency range,and the effective frequency band of the proposed lid can be changed by modifying the geometrical attribute.