Modeling And Signal Integrity Analysis For Multilayer Printed Circuit Boards With Vias

Modern high-speed electronic systems often operate in high frequency range and require thousands of off-chip interconnects to interface heterogeneous components. When designed high-speed digital circuit, some parasitic effects that could be safely ignored before, start to play a critical role in signal quality. vias, a common off-chip intercon-nect, are widely used to connect signal traces on different layers or connect devices to power and ground planes. As discontinuities, vias may cause a lot of signal integrity problems in high frequency. Therefore, an accurate and efficient via model is very important to design the high-speed digital circuit.The entire plate pair is divided into via domains and plate domain in the intrinsic via circuit model. A new two-port model which is based on the intrinsic via circuit model is introduced to analyze the via domains. Then the traditional contour integral method to model the plate domain is improved which makes it more accurate in high frequency. Finally Combined with the modal decomposition method, a complete model for the multilayer printed circuit model with signal traces can be proposed.In the thesis, an inductance and capacitance circuit structure in the intrinsic via model is simplified. First, the electromagnetic around the via can be obtained by using the field analysis method. Then defined the voltage and current based on the interaction between the electronic field and the magnetic field, the impedance of the via domains could be calculated. Different from the intrinsic via circuit model, the two-port black-box model depicted in the thesis doesn’t need to know the concrete circuit structure. Obviously, under the circumstance which the number of the vias is very large,the cal-culated time of the model in the thesis is much shorter than the intrinsic via circuit model.Only the influence of the fundamental mode (TMzoo) is considered in the tradi-tional contour integral method when analyzed the plate domain problem. The influence of a via is assumed focusing on the center of the via, which may be correct in the rel-ative low frequency. But in certain scenarios, such as via-trace transition and vias in very close proximity, the traditional contour integral method can be insufficient. Dif-ferent from the traditional contour integral method, in the improved contour integral method the influence of the higher order modes(TM2m0) is included by discreteing the via boundary, which makes the model more universal.Finally, by utilizing the modal decomposition method, the via-trace transition model could be obtained. Then combined with the result calculated before, a single layer printed circuit board model could be proposed. By using the cascaded S-parameters method, a complete model for the multilayered printed circuit boards with signal traces can be proposed.