Definition

IPC-A-600 is the definitive illustrated guide for visual acceptance criteria of bare printed circuit boards. The four-color document provides photographs showing target, acceptable, and nonconforming conditions for surface quality, hole integrity, conductor dimensions, solder mask, laminate condition, and plating quality. When you specify 'IPC-A-600 Class 2' or 'Class 3' in procurement docs, you're telling the fabricator exactly what defects are acceptable. Class 2 allows minor imperfections (non-functional); Class 3 requires near-perfect boards for high-reliability applications. Every incoming inspection team should have the current version on their bench.