How to improve EMC in multi-layer inverter boards

Employing multilayer board design is an effective way to improve the EMC performance of frequency converters, especially in the control board section. Multilayer boards offer numerous advantages by providing complete ground and power planes: providing low-impedance, continuous mirror return paths for high-speed signals, significantly reducing signal loop area and radiation. The close proximity of the power and ground planes forms natural planar decoupling capacitors, providing excellent high-frequency noise suppression. Alternating arrangement of signal and power/ground planes can be easily achieved, sandwiching sensitive signal layers between two ground planes for optimal shielding.

Area segmentation and isolation are easier, such as appropriately dividing the ground planes of digital, analog, and power drive areas internally. Reduced surface wiring density lowers the risk of crosstalk. A typical 8-layer board stack-up is: S1 (signal), GND2, S3 (signal), PWR4, GND5, S6 (signal), PWR7, S8 (signal). The stack-up should be as symmetrical as possible to prevent warping. Although cost increases, the EMC and signal integrity benefits of multilayer boards are significant for high-performance, high-reliability frequency converters. When assisting customers with PCB EMC design, Yinte Electronics often recommends using a multi-layer board architecture.