Case 1632 ยท Public preview
Termination-Fusion Stress Can Crack a Glass Diode Before Board Assembly
Glass-bodied diodes contained fractures near their terminations and die regions, with additional damage appearing after board-level temperature cycling.
Optical microscopyBackscattered-electron SEMEDSMetallographic microsectioningStock-to-temperature-cycled comparison
What the evidence preview establishes
The diodes were most likely fractured during Sn-Pb termination fusion because differential heating and expansion of the metal leads stressed the glass body. Subsequent temperature cycling propagated secondary cracks from defects already present in stock devices.
Why this case matters
When a glass component cracks after environmental testing, inspect unassembled stock before blaming board-level loading. Alloy trapped in a crack and matching defects in fresh parts can place fracture initiation earlier in the termination-finishing process.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.