Case 1689 ยท Public preview
Improvement after Reflow Does Not Necessarily Establish a Solder-Joint Defect
An assembly with reported faults was submitted for evaluation of one IC's solder joints. Hand reflow had reportedly corrected the problem.
As-soldered examinationBSE SEMEDSMicrosectioningMetallurgical etching
What the evidence preview establishes
The solder joints appeared acceptable. Excessive tin-lead corrosion product between the leads was identified as the most likely explanation for leakage between signals, rather than a solderability failure.
Why this case matters
Treat reflow recovery as a clue, not proof of a solderability defect. Inspect the spaces between signals and correlate residue chemistry with sound joint sections before choosing solder-process correction over contamination control.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, 5 interpreted figures, alternative explanations, limitations, and practical application guidance.