PALLADIUM-GOLD PLATING PROCESS TO SOLVE A LARGE THICKNESS DISTRIBUTION ON HIGH DENSITY PRINTED CIRCUIT BOARD AND PRINTED CIRCUIT BOARD PRODUCED THEREFROM

摘要

The present invention relates to a plating method for solving the thickness deviation of plating, which occurs in a high-density printed circuit board, and a printed circuit board produced thereby. This invention features that a first porous palladium (Pd) plating layer is formed on an exposed soldering portion and a wire-bonding portion of the printed circuit board, which is made of copper or copper alloy, by means of a substitution plating method, a secondary palladium or palladium alloy plating layer is formed on the first plating layer by means of an electroless reduction plating method, and then a gold (Au) or gold alloy plating layer is precipitated and formed on the second plating layer by means of the substitution plating method using the difference of ionization tendency.