Circuit board viaholes and method of manufacturing the same

Abstract

Provided are a circuit board with a viahole and a method of manufacturing the same. The circuit board includes: a substrate formed of an insulating material; a conductive layer disposed on the substrate; a plated layer comprising nickel and disposed on the conductive layer; and a viahole passing through the substrate, the conductive layer, and the plated layer, wherein a crystal growth direction of nickel in the plated layer is parallel to a thickness-wise direction of the substrate.

1 . A circuit board comprising:
 a substrate formed of an insulating material;   a conductive layer formed on the substrate;   a layer of nickel crystals formed directly on the conductive layer; and   a viahole formed through the circuit board;   wherein the nickel crystals of the layer of nickel crystals are grown substantially parallel to a depth-wise direction of the viahole; and wherein a surface roughness (Ra) of the layer of the nickel crystals ranges from 0.4 μm to 0.6 μm and is greater than a surface roughness of the conductive layer.   
     
     
         2 . The circuit board of  claim 1 , wherein a gloss degree of the layer of the nickel crystals is in a range of 0.5 to 2. 
     
     
         3 . The circuit board of  claim 1 , wherein a thickness of the layer of the nickel crystals is in a range of 0.01 μm to 0.5 μm. 
     
     
         4 . A method of manufacturing a circuit board, the method comprising:
 preparing a substrate formed of an insulating material;   forming a conductive layer on the substrate;   plating the conductive layer with nickel to form a layer of nickel crystals formed directly on the conductive layer; and   forming a viahole passing through the circuit board,   wherein the nickel crystals of the layer of nickel crystals are grown substantially parallel to a depth-wise direction of the viahole; and wherein a surface roughness (Ra) of the layer of the nickel crystals ranges from 0.4 μm to 0.6 μm and is greater than a surface roughness of the conductive layer.   
     
     
         5 . The method of  claim 4 , wherein the viahole is formed using a CO2 laser. 
     
     
         6 . The method of  claim 4 , wherein the layer of the nickel crystals is formed by providing a current of 10 ASD (A/dm2) to 30 ASD (A/dm2) to the conductive layer. 
     
     
         7 . The method of  claim 4 , wherein the layer of the nickel crystals is formed by providing a current for 3 seconds to 20 seconds to the conductive layer. 
     
     
         8 . The method of  claim 4 , wherein a gloss degree of the layer of the nickel crystals is in a range of 0.5 to 2. 
     
     
         9 . The method of  claim 4 , wherein a thickness of the layer of the nickel crystals is in a range of 0.01 μm to 0.5 μm.