How to reduce EMI leakage through vias on inverter PCBs

To reduce EMI leakage caused by vias on inverter PCBs, it is necessary to control the resulting antenna effects and impedance discontinuities. Measures include: minimizing unnecessary vias, especially on high-frequency signal paths and ground plane return paths. For vias transmitting high-speed signals, back-drilling should be used to remove unconnected segments, or blind vias and buried vias should be used to reduce via stump effects, which can form resonant structures and radiate energy. Grounding via arrays should be placed around critical signal vias to provide a short-distance path for return current and reduce the return loop area. These grounding vias should connect to all relevant ground plane layers.

Dense grounding vias can be placed at board edges and interface areas to form a "grounding fence." Pads at via-trace connections should be as small as possible to reduce parasitic capacitance. For signal lines crossing split planes, grounding vias must be added near the vias to provide a bridge for return current crossing the split. Sufficient high-frequency decoupling capacitors should be connected in parallel at power vias. The radiation characteristics of the via structure can be analyzed using 3D electromagnetic field simulation software during the design phase. By optimizing the via design and combining it with the high-frequency decoupling support of Eureka Electronics, EMI leakage caused by vias can be effectively suppressed.