Case 2386 ยท Public preview
Material Mismatch at a Silicone Interface Can Fracture LED Bond Wire
Two board-mounted LEDs were electrically open but temporarily regained normal forward voltage when compressed during section preparation.
Electrical testingOptical microscopyMicrosectioningSEMComparative examination
What the evidence preview establishes
Both LEDs opened because their gold bond wires fractured immediately above the silicone encapsulant interface. Thermal-property mismatch concentrated stress at that transition, while gas voids in the silicone likely increased local strain.
Why this case matters
A soft encapsulant can move the stress concentration to its boundary instead of eliminating it. Evaluate encapsulant modulus, CTE, adhesion, voiding, wire geometry, and soldering exposure as one mechanical system.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.