Corrosive Residue Can Convert a Capacitor Termination into a Nonwetting Surface

What the evidence preview establishes

Potassium-rich corrosive contamination attacked the termination solder and exposed oxidized nickel-tin intermetallic that would not wet. Porous copper-nickel metallization and a discontinuous nickel barrier enabled penetration and retention of contamination.

Why this case matters

For isolated nonwetting, examine beneath the visible finish. Porous termination metallurgy can turn external residue into a penetrating corrosion mechanism.