Case 2021 ยท Public preview
Two Opens on Related PCBAs Can Require Two Independent Failure Explanations
Two suspect PCBAs presented open or high-resistance conditions at different interconnect structures.
Optical microscopyElectrical localizationMetallographic microsectioningSEMEDS
What the evidence preview establishes
The connector solder joint failed by creep rupture caused by soldered-in assembly stress, while the PTH via most likely failed because of marginal hole drilling and copper-plating quality.
Why this case matters
Do not force separate opens into one common cause. Localize each electrical discontinuity, preserve the assembly condition, and correlate connector-joint deformation and via-barrel morphology with their respective manufacturing processes.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.