Microsectioning Analysis

Thermal Stress

Solder float testing and reflow simulation expose the prepared sample to extreme heat before sectioning takes place to verify barrel wall integrity against thermal shock. Plated through holes experience high mechanical stress when rapid temperature increases expand the surrounding epoxy faster than the electrodeposited copper barrel, which frequently causes inner layer separation or barrel cracking. Quality engineers measure copper thickness, nodule dimensions, and dielectric spacing tolerances on the polished plane to confirm compliance with acceptance standards before releasing production lots to downstream assembly lines.

Acceptance Criteria

Microsectioning analysis establishes final compliance for circuit boards by setting hard numerical limits on copper wrap, plating thickness, and etchback depth that suppliers must satisfy prior to customer shipment. Acceptance decisions rely on dimensional measurements taken across specific zones of the prepared sample, where any observed plating void or laminate void exceeding published limits results in immediate lot rejection. Verification of proper intermetallic growth thickness at joint interfaces prevents brittle joint failures during subsequent surface mount technology assembly processes.