Abstract: The quality of PCB routing and layout in household air conditioning systems is decisive for their anti-interference performance in complex electromagnetic environments. Existing design methodologies struggle to reliably predict immunity against Electrical Fast Transient/Burst (EFT/B) disturbances due to the intricacy of electromagnetic coupling paths. To address this challenge, a PCB layout optimization method based on critical parameter analysis and co-simulation is proposed. This research establishes a quantitative mapping model between EFT coupling paths and layout parameters, resolving the opaque nature of coupling mechanisms in traditional design approaches. A closed-loop workflow integrating co-simulation, parameter quantification, and design optimization is constructed using the ANSYS toolset, enabling comprehensive digital verification from root-cause fault identification to optimization effectiveness quantification. Ultimately, an engineering-ready design scheme centering on minimizing critical loop inductance and harmful coupling is developed. Experimental results demonstrate that this approach significantly enhances EFT immunity, reduces the average number of board revisions, and improves first-pass yield in compliance testing. This methodology facilitates the digital transformation of EMC quality management in the household appliance industry toward a proactive prevention paradigm.

Key words: EFT/B, PCB Layout optimization, Co-Simulation, Parametric analysis, Reliability enhancement