Case 2020 ยท Public preview
Flux Residue Can Develop into a Leakage Path Between FET Leads
Two recalled assemblies were suspected of electrical faults in a circuit region containing closely spaced FET leads.
Optical microscopyIn-circuit electrical testingSEMEDSElemental mappingRecalled-working comparison
What the evidence preview establishes
The recalled assemblies contained more severe flux residue and corrosion around the FET leads than a working comparison. Chloride-bearing, tin-rich corrosion product extended between adjacent leads and created a credible path for electrical leakage and eventual hard failure.
Why this case matters
Do not judge no-clean residue only by appearance. Compare failed and working assemblies, map corrosion chemistry across biased conductors, and test leakage under controlled humidity before corrosion progresses to an intermittent or catastrophic electrical fault.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.