Optimization of 2.5D Organic Interposer Channel for Die and Chiplets

This paper systematically analyzes the impact of various physical design parameters on the electrical performance and optimizes the digital channel on a 2.5D organic interposer. The analysis focusses on mapping the impact of design parameters such as line width, spacing, dielectric thickness, metal thickness, presence of ground plane, and routing configuration on the bandwidth performance of the interconnect channel. It was observed that, while the cross-section of an interconnect played a role in the resistance, there are instances when the capacitive and inductive crosstalk and return-path coupling overshadow the benefits of a larger cross-section area. Further, Ground Signal Ground (GSG) routing configuration that seems less efficient, has been shown to offer performance gains and improved routing density over standard microstrip line (MSL). It has also been validated that, depending on the routing configuration, parameters such as the dielectric thickness or the presence of a ground plane may not have any impact on the performance; and hence offer additional freedom in terms of design and cost. Finally, optimization of a 2.5D interposer channel using GSG configuration has been presented.