Which characteristic poses a particular corrosion problem on printed circuit board edge connectors?

Thinly coated surfaces on printed circuit board (PCB) edge connectors are particularly prone to corrosion due to their inadequate protective layer. In electronics, edge connectors often need to maintain electrical conductivity while also being resistant to environmental factors that cause corrosion. When a surface is thinly coated, it can expose underlying metals to moisture, humidity, and contaminants, which can initiate and accelerate the corrosion process.

In applications involving PCB edge connectors, a robust protective coating is essential to prevent corrosion that could impair electrical connections. Thin coatings are not effective barriers against corrosive agents, which can lead to increased resistance at connection points or even complete failure of the electrical circuit over time. This makes it critical to ensure that coatings used are sufficiently thick and durable to withstand environmental challenges.

The other characteristics listed, such as thickly coated, rough, or abrasive surfaces, either provide better protection against corrosion or do not significantly impact corrosion susceptibility in the same way that thinly coated surfaces do. Therefore, understanding the implications of surface coating thickness is vital in the design and maintenance of electronic components to enhance their longevity and reliability in aviation applications.