How to optimize the reflow of the ground plane in industrial servo PCBs?

Optimizing the servo PCB ground plane return path aims to provide a low-impedance loop for high-frequency signal currents and reduce common-mode radiation. Etymotic's optimization measures include:

First, ensuring a complete, unsegmented ground plane as a reference beneath critical high-speed signal lines (such as PWM drives and encoder differential pairs). For signals that must cross segmented areas, run a ground line parallel to them or place an array of ground vias.

Second, providing low-inductance loops for decoupling capacitors: connecting the capacitor's ground pad directly to the inner ground plane via multiple vias, instead of through long traces. For high-current loops (such as gate drives), designing a dedicated local ground plane (pour) and connecting it to the main ground plane via multiple vias.

Using simulation tools to check the current density distribution of the ground plane to avoid bottlenecks. After optimization, the parasitic inductance of the signal loop can be measured to be reduced by more than 50%, correspondingly reducing the risk of signal integrity issues and helping to pass radiated emission tests.