To achieve independent identification of each printed circuit board, ensure quality consistency in inspection, and maintain traceability between the identification components and their manufacturing history and suppliers, the surface should be marked. The identification content includes the manufacturer’s trademark, production date of the printed board, batch number (traceability code), etc. Common identification methods include wet etching, laser marking, screen printing ink, inkjet printing, and label application.
Conductive markings (etched copper or conductive ink) should be considered as electrical components of the circuit and must not reduce the electrical spacing requirements. All markings should be compatible with materials and components, and should remain clearly discernible during all tests (including corrosion from solder, cleaning solutions, and molten solder during the manufacturing, assembly, and usage processes) and must not affect the performance of the printed board under any circumstances.
Figure 1 Common Identifications on the Surface of Printed Boards
Figure 2 Conductive Markings