Method for forming plating layer of printed circuit board

Abstract

Disclosed herein is a method for forming a plating layer of a printed circuit board. A deviation in plating thickness of a copper plating layer filled in a circuit pattern part and a through-hole part in a SIP product group having a narrow through-hole pitch and a large through-hole volume may be reduced. To this end, there is provided a method for forming a plating layer of a printed circuit board, the method including: processing a though-hole in a copper clad lamination (CCL); forming a seed plating layer in the through hole; applying a resist on the CCL and the seed plating layer and exposing and developing the resist; forming a primary plating layer on the seed plating layer; forming a copper plating layer on the primary plating layer; and removing the resist remaining on the primary plating layer and the seed plating layer to thereby form patterns.

What is claimed is: 
     
         1 . A method for forming a plating layer of a printed circuit board, the method comprising:
 processing a though-hole in a copper clad lamination (CCL);   forming a seed plating layer in the through hole;   applying a resist on the CCL and the seed plating layer and exposing and developing the resist;   forming a primary plating layer on the seed plating layer;   forming a copper plating layer on the primary plating layer; and   removing the resist remaining on the primary plating layer and the seed plating layer to thereby form patterns.   
     
     
         2 . The method according to  claim 1 , wherein the through-hole is formed by a mechanical method and a chemical method. 
     
     
         3 . The method according to  claim 2 , wherein the mechanical method is a drill and laser processing method, and the chemical method is an etching method. 
     
     
         4 . The method according to  claim 1 , wherein the primary plating layer has a thickness of 3 to 5 μm. 
     
     
         5 . The method according to  claim 4 , wherein the primary plating layer is plated with a low current having a current density of 0.5 A/dm 2  to 1.0 A/dm 2  or less. 
     
     
         6 . The method according to  claim 1 , wherein the copper plating layer is formed on the primary plating layer so as to have a thickness of 20 to 25 μm. 
     
     
         7 . The method according to  claim 6 , wherein the copper plating layer is plated with a high current having a current density of 1.5 A/dm 2  to 2.0 A/dm 2  or more.