Meaning
Physical anomalies created during the fabrication or assembly of printed circuit boards compromise the mechanical and electrical integrity of the product. Recognizing a structural defect early prevents the field failure of critical subassemblies. These physical issues include solder voids and copper cracks.
Origin Point
Manufacturing variations during the etching or plating phases often lead to these physical issues. Incorrect temperature profiles during the solder reflow process can also create voids under ball grid array components. Tracking these thermal parameters helps to isolate the mechanical root causes before large batches are run.
Inspection Technique
Identifying internal board anomalies requires advanced imaging and testing methods. Automated optical inspection captures surface irregularities, while automated X-ray inspection reveals hidden faults within multilayer structures and solder joints. These visual checks are coupled with electrical tests to confirm the continuity of all signal paths.
Combined analysis ensures that even microscopic anomalies are documented before the product leaves the facility, preventing shipping bad parts.
Reliability Risk
Latent anomalies that escape initial testing often lead to early failure during thermal cycling in the field. Repeated heating and cooling cause the materials to expand at different rates, widening minor fractures into open circuits. This risk is minimized by performing burn-in tests.
