Not Suspect

Flux Residue Caution

Visible residue on a tin-plated lug surface that should not automatically be treated as a meaningful failure mechanism.

Scale 500 um scale shown
Observed feature Localized flux residue on a tin-plated lug surface under removed insulation
Likely mechanism Residue consistent with flux that may not represent a significant reliability concern
Localized flux residue on a tin-plated lug surface

Interpretation

Why this image matters

The report concluded that the contamination under the insulation was consistent with flux residue and may not represent a significant reliability concern if the flux was no-clean.

The residue is real and visible, but the correct interpretation is more restrained than many users might expect.

This kind of image emphasizes judgment, not just mechanism vocabulary.

flux-residue interpretation-training incidental-residue contamination
Use this when

Best comparison value

  • Teaching that visible residue is not automatically a root cause
  • Comparing meaningful contamination to low-significance residue
  • Discussing the importance of process context before making conclusions