Humidity-driven corrosion effects on PCB design analysed using a digital twin approach

The use of electronics in many climates and high- and low-voltage applications elevates the propensity for humidity-driven failure mechanisms like leak current (LC) and electrochemical migration due to water film formation on printed circuit board assembly (PCBA) surfaces. Therefore, optimizing creepage in critical areas of PCBA layouts is critical to mitigate high-voltage-related issues. This study combines two types of simulations providing a predictive methodology simulating effects of different layout designs and parameters like water film electrolyte properties and voltage levels. The first uses ‘secondary current distribution’ physics in COMSOL on a three-dimensional two-electrode PCB layout with multi-parameter variability (water layer thickness, conductivity, electrode dimensions, pitch distance and supply voltage), outputting LC data. Physical testing using test PCBs serves as validation. The second is numerical simulation using the multivariate adaptive regression splines (MARS) algorithm. LC data from COMSOL trains the MARS model to understand parametric interactions. A correction factor derived from comparing COMSOL and physical test data corrects the MARS model, creating an ML model connecting PCBA design parameters with water film characteristics.