Impact of GND-PTH stitches in DDR3/GDDR3/GDDR5 Memory controller packages

DDR3 and GDDR3/5 memory technology running in the Giga-bit range require 3D EM accurate modeling of RF phenomena such as the impact of G ND-PTH stitches (G round Plated Through Hole) used to connect reference ground-planes in the Memory controller packages (MCH-PKG). Cost-reduction requires minimizing the number of layers and vias on MCH-PKG (micro-vias and PTH). Layout-Designers usually revert to reduce the GND-PTH without studying the impact on the performance. In this paper, Method of Moments (MoM) is used to study the impact of GND-PTH on data eye-opening as well as on Radiated-Emission of a DDR3 two-SODIMMs/channel running at 1.33GB/s.