Electrical behavior of stacked microvias integration technologies for multi-gigabits applications using 3D simulation

Embedded electronics merge always more and more enhanced functionalities, which implies that the printed circuit boards (PCB) need to achieve higher integration levels. Furthermore, signal integrity must be ensured, and the increasing use of multi-gigabits serial links requires a detailed analysis of the electrical behavior of tracks and vias for frequencies up beyond 10MHz. Thus, the different stack-up are enhanced in order to satisfy data rate beyond 10 Gbps. This paper relies on stacked microvias, which are a very innovative technology permitting a better level of integration compared to usual microvias or through hole vias. Indeed, they have a very good electrical behavior on a large frequency range (DC to 18 GHz) contrary to classical through hole via where possible stub effects deteriorate signal integrity. Moreover, it is easier to optimize the stacked microvia structure compared to standard microvias. Electrical characterization of these vias structures are evaluated through measurement on test vehicles and 3D modelling using CST Microwave Suite.