Method of manufacturing a film printed circuit board

Abstract

A method of manufacturing a film printed circuit board is provided. A film substrate consisting of a polyimide substrate, an alloy layer and a first copper layer is provided. A first lithographic and etching process is performed to pattern the copper layer and the alloy layer and a plurality of conductive line structures is formed on the polyimide substrate. A second copper layer is formed over the polyimide substrate and the conductive line structures. A second lithographic and etching process is performed to pattern the second copper layer.

1 . A method of manufacturing a film printed circuit board, comprising the steps of:
 providing a film substrate having a first metal layer;   performing a first etching process to pattern the first metal layer, and a plurality of first conductive line structures are formed on the film substrate;   forming a second metal layer over the film substrate and the first conductive line structures; and   performing a second etching process to pattern the second metal layer.   
     
     
         2 . The method of manufacturing a film printed circuit board as claimed in  claim 1 , wherein the first metal layer comprises Ni—Cr alloy. 
     
     
         3 . The method of manufacturing a film printed circuit board as claimed in  claim 1 , wherein the first etching process comprises:
 forming a photo resistant layer on the first metal layer;   patterning the photo resistant layer for exposing parts of the first metal layer;   etching the first metal layer, which is exposed, by a wet etching process until the film substrate is exposed; and   removing the photo resistant layer.   
     
     
         4 . The method of manufacturing a film printed circuit board as claimed in  claim 3 , wherein the first metal layer comprises copper. 
     
     
         5 . The method of manufacturing a film printed circuit board as claimed in  claim 1 , further comprising covering the film substrate and the first conductive lines with a copper crystal seed layer. 
     
     
         6 . The method of manufacturing a film printed circuit board as claimed in  claim 5 , wherein the step of covering the film substrate and the first conductive lines with the copper crystal seed layer comprises a sputtering process. 
     
     
         7 . The method of manufacturing a film printed circuit board as claimed in  claim 1 , wherein the step of forming the second metal layer comprises an electroplating process. 
     
     
         8 . The method of manufacturing a film printed circuit board as claimed in  claim 1 , wherein the step of forming the second metal layer comprises a chemical plating process. 
     
     
         9 . The method of manufacturing a film printed circuit board as claimed in  claim 1 , wherein the second etching process comprises:
 forming a photo resistant layer on the second metal layer;   patterning the photo resistant layer, the patterned photo resistant layer are positioned over the first conductive line structures;   etching the second metal layer, which is exposed, by a wet etching process until the film substrate is exposed; and removing the photo resistant layer.   
     
     
         10 . The method of manufacturing a film printed circuit board as claimed in  claim 1 , wherein the second metal layer comprises copper. 
     
     
         11 - 15 . (canceled)