Fabrication Separation
Routing geometry gaps occur when the drilling tool exits the copper trace outline during the final board profile separation. A mousebite defect develops when the bit trajectory deviates from the programmed path, creating an irregular notch along the board edge. This condition creates stress concentrators that weaken the structural integrity of the composite substrate.
Micro-cracking often propagates from these uneven indentations under thermal load or mechanical shock.
Processing Verification
Optical inspection systems detect these edge irregularities by comparing the physical board profile against the original manufacturing data. Automated machines identify the anomaly when the copper feature boundary exceeds the tolerance specified for the board perimeter. Engineers monitor the tool wear rate to prevent the drill bit from wandering during the final routing sequence.
Precise calibration of the spindle speed and feed rate prevents the mechanical vibration that causes the bit to bite into the circuit area.
Assembly Consequence
Loose copper shards from these edge gaps represent a high risk for electrical shorting during the soldering phase. Metallic debris migrates across the substrate surface and potentially bridges adjacent pads or conductive planes. Component placement machines struggle with inconsistent board registration when the edges lack a smooth finish.
Proper edge routing maintains the electrical insulation distance required for high voltage applications. Rigid adherence to tool replacement schedules prevents this defect from affecting the final product yield.
