Transient analysis of three—dimensional electromagnetic field in through—holes

Through‐holes are attached to numerous structures in mutual connections of electronic devices, printed circuit boards which provide supporting functions, multilayer wires of LSI, and external connections of IC packages. With the recent uses in superhigh‐frequency waves in superminiaturized circuits, the influences of through‐holes on the propagation characteristics are becoming increasingly nonnegligible. To understand the characteristics of the total system, analyses of through‐holes have become indispensable. However, through‐holes generate complicated distributions of electromagnetic fields due to their three‐dimensional structures. Thus, it is necessary to perform rigorous vectorial analyses for three‐dimensional fields using all field components, boundary conditions, and properties of the medium. Hence, for analysis of through‐holes, we applied the method of spatial networks. These networks have many features for analyses of electromagnetic fields in obtaining time responses of the three‐dimensional fields. We simulated their basic field behaviors, and obtained transmitted output waves which provide an important influence of a through‐hole on characteristics of high‐speed pulse operations and reflected wave shapes toward the input terminals. We determined the frequency characteristics of those wave shapes by fast Fourier transforms, and clarified the effectiveness of the application of the present analysis method.