Study On The Simulation Of Interconnects In Microwave Multi-Chip Module

During the last half century, it is rapidly developing of microwave circuit technique either from low frequency to high frequency or from single layer to multiple layers that leads to the coming of microwave multi-chip module (MMCM). With the increasing density of multi-chip module, the discontinuity of interconnect is the choke point which restrains its integral performance. Hence, it is significant for the design of MMCM to simulate and model of interconnect. The work in this dissertation is, focused on the problem of vertical via interconnect, to fulfil numerical and software simulation on via's scattering parameter. Some useful results are obtained. Main study contains the following:Firstly, Matrix-penciled moment method with piecewise sinusoidal basis function is used to analysis and compute via's scattering parameter of microstrip-via-microstrip interconnect model of multi-layered environment. Some laws of scattering parameter in the interconnect structure are shown while to change via's geometric parameters. Another analysis is made by considering B-spline function as the basis function to carry the same process. By contrast, the former is feasible to solve the vertical via interconnect problem for the acceptable precision and the cost of implement.Secondly, considering microstrip-via-microstrip interconnect structure, for the case that microstrip connecting angle is arbitrary, simulation is programmed in Ansoft Ensemble 7.0 simulation software so as to obtain scattering parameter and radiation power. The inherent relationship between changes of scattering parameter and radiation power is explored and reported when microstrip connecting angle changes.Thirdly, the object to simulate is microstrip-via-microstrip interconnect model of MMCM in LTCC, equal-distance and symmetric adding coaxially shielding via around signal via. With the simulation of signal via's 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 microstrip and stripline can improve evidently the scattering parameter of signal via. But if adding progressively shielding via, its scattering parameter will become worse.Fourthly, the object to study is CPW-CPW flip-chip interconnect structure. Scattering parameter of solder bump in flip-chip structure is analyzed by using FDTD. It is shown from result of numerical experiment that the less the bump's height and width are, the better of its scattering parameter. It is also come out that the bump's inductance which is proportioned to its length is the major factor to cause discontinuity. 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.Lastly, the advantage and disadvantage of two methods, namely matrix-penciled moment method and FDTD method, is presented by contrast. FDTD method is better than the other one for vertical via interconnect problem. Because vertical via interconnect is the base of theoretical analysis and package technics of MMCM, further study on vertical via interconnect is very vital and instructive to reality.