Research Of The Electromagnetic Compatibility Characteristics Of Typical Package

With the rapid development of the electronic technology, the passive components of the IC chips, such as capacitors, inductors and resistors occupy an increasing proportion. At the same time, the number of components is increasing and the size of chip is dreasing, which leads to the electromagnetic compatibility (EMC) problems become more and more complexity. So, it has become a serious problem of how to improve the circuit package density, to distribute the components of the chip rationally and to reduce the electromagnetic interference (EMI). Meanwhile, IC chip becomes more and more complexity because the semiconductor revolution drives the chip clock frequency getting faster and the noise margin for the device becomes narrower than before. Therefore, package has become the bottleneck in the high-frequency integrated circuit design, which makes a great influence on the system reliability in the aspects of signal integrity and loss.So, it is extremely important for the IC package design Engineer to simulate the EMC of the IC package and analysis of the signal integrity of the package, expecially fot the the radio frequence (RF) products.The package forms of Quad Flat Pack(QFP) and Ball Grid Array (BGA) have been introduced in this paper. The electronic field and magnetic field surface distributions of these two kinds package have been obtained by the physical modeling of the3D finite element and the simulation of the EMC in high frequency. Then the RLC parameters matrix and the Hspice models of the two kinds package can be outputed by the Ansoft Q3D Extractor. A two-port lumped equivalent circuit model has been constracted according to the two kinds package with Multisim tools. On the basis of the traditional lumped equivalent circuit, a coupling capacitance has been introduced to the inproved lumped equivalent circuit which will be provided for the circuit simulation in high frequency.Finally, signal integrity of the both kinds of package has been analysised respectively according to the equivalent circuit model, which includes the transient analysis, noise analysis, AC analysis, sensitivity analysis as well as the near field scan analysis. The conclusion can be obtained that the high-frequency EMC characterize of the BGA package is better than the QFP package by comparing the EMC simulation and the analysis of SI of these two kinds of package. The3D physical modelings and the equivalent circuit which are described in this paper are found to be more accurately and rapidly, which can be used to provide reliable parameter for the IC design engineers and will have a great significance on the research of the EMC for high-speed digital circuits.