Destructive Inspection
Destructive physical analysis remains the definitive method for evaluating the internal construction of a printed circuit board. In structural microsection verification, a sample coupon is cut from the panel, mounted in epoxy resin, and polished to expose a specific vertical plane of the plated holes. This preparation allows inspectors to measure the thickness of internal copper foil, plating, and dielectric layers under a high power microscope.
It confirms that the finished board complies with the mechanical drawings and industry specifications.
Quality Measurement
Plating thickness measurements are taken at several points along the via barrel to ensure uniformity. This check prevents thermal failures by confirming that the copper in the hole meets the minimum thickness requirement. It also detects issues like inner-layer separation and resin recession.
Manufacturing Feedback
Process correction in the wet chemistry and lamination stages depends on feedback from these cross-sectional evaluations. When the microsection reveals plating voids or drilling burrs, the fabrication line operator must adjust the desmear and electroplating parameters immediately to prevent future batch failures. This analysis acts as a gatekeeper for the release of high reliability circuit boards destined for harsh environments.
It ensures that hidden anomalies are resolved before the batch undergoes final electrical testing and assembly.
