The invention relates to a method for improving the graphic accuracy of a substractive process
printed circuit board (PCB) by adopting a dynamic
etching compensation method. The method comprises the following steps of: step 1: studying the influence of thickness differences of base
copper over
etching line width and line distance so as to obtain the
line width difference value ability ranges corresponding to the PCB base
copper in different thickness ranges, and studying the influence of different areas, different line directions and different line graphs over
etching compensation parameters so as to obtain etching compensation parameter ranges of compact lines, isolated lines, surface-
mount technology (SMT) bonding pads and
ball grid array (BGA) bonding pads; step 2: determining an average etching compensation value according to step 1 in accordance with the base
copper thickness in an original draft of the PCB so as to firstly and averagely compensate films of all line graphs; and step 3: additionally compensating films of the compact lines, the isolated lines, the SMT bonding pads and the BGA bonding pads by adopting dynamic etching compensation
software. By adopting the method disclosed by the invention, the influence of the base copper thickness, the etching uniformity and the like over the
line width of the areas such as the compact lines, the isolated lines, the SMT bonding pads and the BGA bonding pads can be eliminated.