GB/T 13557-1992 specifies the test method for flexible copper-clad materials for printed circuits. The standard covers tests of Appearance, Size, Copper Foil Adhesion, Electrical Performance, etc., detailing the operation procedures, equipment and judgment criteria for various tests. These tests are essential for evaluating material mass and ensuring printed circuit Reliability. It provides unified specifications for relevant manufacturers and testing institutions to help control product mass, ensure that flexible copper-clad materials meet the needs of printed circuit manufacturing, promote the standardization of material mass testing in this field, and promote the stable development of the printed circuit industry.