Keith Rogers, Craig Hillman, and Michael Pecht
CALCE Electronic Products and Systems Consortium
University of Maryland
College Park, MD 20742
Honeywell Inc., Minneapolis, MN 55413
A defective printed circuit board assembly that exhibited excessive current leakage was examined to determine the responsible failure mechanisms. Observation of the failure site (determined electrically) by optical and electron microscopy revealed an area in the circuit board where debonded fiber bundles bridged a from plated-through-hole (PTH) to a copper plane. This phenomenon is highly suggestive of conductive filament formation.