Case 2235 ยท Public preview
Passivation Loss and Surface Ions Can Both Threaten Sensor Output
Returned thin-film strain-beam sensors reportedly showed output shifts. New and returned units were supplied, some with silicone coating retained and others with coating previously removed.
New-to-returned comparisonOptical microscopyBSE SEMEDSCoating-coverage comparison
What the evidence preview establishes
Two observed conditions could contribute to the output shifts: spalling of Ta2O5 passivation over metallization and ionic surface contamination capable of promoting leakage between signals. The report did not isolate a single electrical mechanism.
Why this case matters
For thin-film sensors, compare passivation continuity, coating coverage, and surface ions across new and returned units. Keep potential mechanical and electrical pathways separate until targeted tests connect a localized defect to an output shift.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, 4 interpreted figures, alternative explanations, limitations, and practical application guidance.