Method for processing patterns in blind slot of printed circuit board

The invention discloses a method for processing patterns in a blind slot of a printed circuit board. The method comprises the following steps of drilling a hole in the printed circuit board; forming an inner copper layer on the printed circuit board; milling the blind slot with controlled depth on the printed circuit board; exposing the inner copper layer at the bottom of the blind slot; carrying out electroless copper plating on the printed circuit board, wherein the electroless copper plating areas comprise the bottom and the side walls of the blind slot; plating gold on the surface of the printed circuit board, wherein the gold plating area comprises the bottom of the blind slot; using an ultraviolet ray to burn the gold on the area to be isolated at the bottom of the blind slot, and exposing the copper surface; and corroding the exposed copper on the area to be isolated at the bottom of the blind slot, so as to form a circuit pattern at the bottom of the blind slot. The method disclosed by the embodiment of the invention has the advantages that the metallizing of the side wall of the blind slot is realized, the metallic through hole and the circuit pattern are manufactured at the bottom of the blind slot, and the qualified rate of the pattern is improved.