Case 736 ยท Public preview
Micron-Scale Die-Attach Separation Can Dim or Interrupt an LED
Three LEDs showed degraded brightness or a brief interruption after humidity and rapid-decompression testing.
Optical microscopySequential cross-sectioningSEMInterface comparisonInterconnect assessmentMulti-device comparison
What the evidence preview establishes
Damage and approximately 1-2 microns of separation at the die-to-die-attach interface increased series resistance and created a credible intermittent-open path. Thermal-expansion stress, physical stress during rapid decompression, or both displaced the dice from their mounting pads.
Why this case matters
For LED dimming or intermittent operation after pressure testing, inspect the die-attach interface as well as the visible wire bonds. Micron-scale die displacement can increase series resistance even when the solder, ball bond, and wedge bond remain intact.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.