Microwave Multi-chip Module Interconnect Structure Electromagnetic Compatibility

The work in this paper is focused on the problem of Electromagnetic Interference (EMI) route and its effect (interconnection, coupling) on MMCM. A three dimensional (3D) microwave transmission structure was studied in this paper. It includes works for: establishing the forecasting EMI model, extracting the electromagnetic parameters of the interconnection structure and the coupling structure based on the analysis of EMI route of the forecasting EMI model. Main study contains the following:1. A coupled model which contains a group of 10mm long parallel micro strips is used to be analysis and compute its scattering parameter and coupling coefficient. Some laws of coupling coefficient in the model are shown while to change the interval between the lines, it is shown from result of simulation experiment that the bigger the micro strips'interval is, the less of its coupling coefficient. Some ways of decrease interference and validated them is brought forward based on the analysis of the numerical result obtained through simulation preceding.2. The object to simulate is the signal via model of MMCM, equal-distance and symmetric adding coaxially shielding via around signal via. If two vertical signal vias'distance is too small, the coupling of them will be increased evidently, by adding shielding via between them, the coupling coefficient of the vertical signal via can be decreased. With the simulation of signal via scattering parameter, conclusion that shielding via can improve the scattering parameter of signal via. Considering that there exists synchronously coaxially shielding via, simulating result shows that to add a layer of dielectric between micro strip and strip line can improve evidently the scattering parameter of signal via. But if adding progressively shielding via, its scattering parameter will become worse. If two vertical signal via distance is too small, the coupling of them will be increased evidently, by adding shielding via between them, the coupling coefficient of the vertical signal via can be decreased.3. Considering the CPW-CPW flip-chip interconnect structure. It is come out that both the case that the overlap part's length between upper and lower layer CPW becomes short, and the case that dielectric constant of the chip, mother board, and media between the chip and mother board becomes small, the bump's scattering parameter can be improved.