Printed circuit board having metal bumps

Abstract

A printed circuit board includes an upper circuit layer including a circuit pattern embedded in an upper part of an insulating layer, the circuit pattern being made of electroconductive metal; and a metal bump formed on the circuit pattern and the insulating layer

What is claimed is: 
     
         1 . A printed circuit board comprising:
 an upper circuit layer including a circuit pattern embedded in an upper part of an insulating layer, the circuit pattern being made of electroconductive metal; and   a metal bump formed on the circuit pattern and the insulating layer.   
     
     
         2 . The printed circuit board according to  claim 1 , wherein a portion of a lower surface of the metal bump is connected to the circuit pattern. 
     
     
         3 . The printed circuit board according to  claim 1 , further comprising a solder resist layer disposed on the insulating layer and having an opening through which the metal bump is exposed. 
     
     
         4 . The printed circuit board according to  claim 1 , further comprising a lower circuit layer embedded in a lower part of the insulating layer. 
     
     
         5 . The printed circuit board according to  claim 1 , further comprising a surface protection layer disposed on the metal bump, the surface protection layer being composed of an OSP surface-treated layer or a nickel and gold plating layer. 
     
     
         6 . The printed circuit board according to  claim 1 , wherein the circuit pattern and the metal bump are made of copper (Cu), tin (Sn), or an alloy of tin (Sn) and silver (Ag). 
     
     
         7 . The printed circuit board according to  claim 4 , further comprising a via for an electrical connection between the circuit pattern and the lower circuit layer.