Case 2444 ยท Public preview
Excessive Heat-Shrink Processing Can Remelt a Soldered Thermistor Joint
One thermistor assembly had a high-resistance wire joint and visibly heat-damaged heat-shrink tubing.
Resistance testingOptical microscopyMicrosectioningSEMEDS ratio comparisonImage-area measurement
What the evidence preview establishes
Excessive heating during heat-shrink processing remelted the failed solder joint and allowed most of its solder to flow away. The affected joint retained only about 13% of the average solder area of the other three joints, while the damaged assembly also showed evidence of greater copper dissolution into the solder.
Why this case matters
Use heat-shrink discoloration as a process-warning signal and control the lead-to-wire geometry before heating. A component lead riding on insulation forces the conductors apart, while excessive heat can remelt the joint and move solder out of the intended connection.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.