Case 2435 ยท Public preview
Bond Cratering Can Hide Beneath Apparently Intact Semiconductor Pads
Several packaged microcontrollers developed infant-mortality failures, open signals, and thermal intermittency that could sometimes be affected by heating or cooling.
Electrical continuity testingX-ray imagingCSAMChemical decapsulationSEM and EDS
What the evidence preview establishes
Bond cratering introduced during wire bonding was the most likely primary failure mechanism. Multiple devices contained fractured or incipiently fractured structures beneath bond pads, while reduced aluminum at other pads supported corrosion as a secondary mechanism.
Why this case matters
An intermittent semiconductor open may originate beneath an apparently present bond. Combine continuity data with acoustic inspection and decapsulation, then distinguish subsurface bond cratering from chemically depleted aluminum pads because the corrective actions belong to different processes.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, 4 interpreted figures, alternative explanations, limitations, and practical application guidance.