How to improve EMC in motion controller MC multilayer board stacking

Utilizing a well-designed multilayer board stack-up is an effective way to systematically improve the EMC performance of motion controllers. A typical four-layer board stack-up consists of a signal layer, a ground layer, a power layer, and another signal layer. Placing high-speed signal layers adjacent to a complete ground layer confines electromagnetic fields within the dielectric, reducing radiation. Power layers should be tightly coupled to their adjacent ground layers, forming natural decoupling capacitors. Six-layer or more boards can add ground planes to provide more shielding for sensitive signals. Symmetrical stack-ups can be designed to reduce warpage and balance impedance.

When dividing power planes between different power domains, ensure the continuity of the underlying reference ground plane. Use arrays of ground vias along the board edges to connect all ground planes, creating a Faraday cage effect. A well-designed stack-up facilitates clear zoning, such as placing analog circuitry in a corner with its own independent ground plane. By controlling the dielectric constant and thickness, impedance and signal speed can be precisely managed, fundamentally improving signal integrity and EMC.