Case 2455 ยท Public preview
A Weak LED Ball Bond Can Lose Support as the Lens Delaminates
Two LEDs were open-circuit even though their semiconductor dice remained functional when probed directly.
Electrical testingOptical microscopyMicrosectioningSEMDirect die probingFailed-device comparison
What the evidence preview establishes
One or both die ball bonds failed as the lens material delaminated from the die surface. The unusually spherical, minimally deformed bonds indicated under-bonding and weak mechanical support, making the interconnects vulnerable to thermomechanical stress.
Why this case matters
When an LED is open but its die remains functional, distinguish the die circuit from the wire-bond path. Evaluate ball deformation and lens adhesion together because a weak bond can remove local support while interface delamination applies additional stress.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.