Case 216 ยท Public preview
Interfacial Melting Points to Reverse-Bias Stress in Tantalum Capacitors
Four field-returned solid tantalum capacitors were electrically shorted and exhibited localized thermal damage.
Electrical testingOptical microscopyCross-sectioningSEMDamage-location comparisonFailure-morphology interpretation
What the evidence preview establishes
Reverse-bias stress was the leading explanation for localized electrical breakdown and alloying at the tantalum-slug to manganese-oxide interface. Moisture-assisted degradation remained an alternative if reverse-bias transients could be eliminated.
Why this case matters
A shorted tantalum capacitor with localized interfacial melting should trigger a circuit-level search for reverse-bias transients. Preserve moisture exposure as an alternative until electrical history and environmental controls are verified.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.