Boundary Threshold
Final verification determines whether manufactured hardware conforms to agreed production drawings and performance criteria before ownership transfers from fabricator to buyer. Printed circuit acceptance establishes the contractual and technical divide between acceptable yield loss and lot rejection based on measured physical deviations. Electrical continuity checks, microscopic cross sectioning, and solderability assays provide the evidentiary basis for this determination.
Specifications derive from established standards that govern conductor width, dielectric spacing, and plating thickness tolerances. Deviations exceeding allowed limits trigger scrap procedures or formal material review board dispositions rather than unverified rework.
Verification Protocol
Optical inspection systems scan copper pattern geometry for etching defects, bridging, and annular ring violations before mask application. Automated test equipment applies specific voltages to net lists to detect opens, shorts, and high resistance anomalies within internal layers. Thermal stress testing exposes coupon samples to molten solder temperatures to evaluate barrel cracking resistance and laminate integrity.
Dimensional verification uses coordinate measuring machines to confirm mounting hole locations and board profile edges match fabrication drawings.
Defect Disposition
Nonconforming lots undergo documented engineering review to determine whether anomalies compromise functional reliability or remain purely cosmetic. Trace width reductions within standardized percentage tolerances often receive conditional approval under controlled service life assumptions. Structural delamination or broken internal traces permit no structural concessions and mandate immediate scrap disposition.
Final release documentation accompanies accepted shipments to certify compliance with purchase order requirements and reference standards.
