Method of Manufacturing Double-Sided Printed Circuit Board

Abstract

The present invention provides a method of manufacturing a double-sided printed circuit board. An insulation substrate is first formed by creating a plurality of through holes on a Copper Clad Laminate (CCL) whose copper foil surface has been removed. Next, an electro-less copper layer is plated on the substrate for forming a plurality of plated through holes. After a wire pattern is formed on the substrate, a solder preventive layer is formed on top of the wire pattern. Next, a plurality of openings is created in between the solder preventive layer for exposing the contact pads. Finally, a protective layer is plated on top of the contact pads.

1 . A method of fabricating a double-sided printed circuit board, the method comprising: 
 providing a copper clad laminate (CCL), wherein the CCL comprises an insulating substrate and at least one copper clad disposed on the surface of the insulating substrate;    performing an etching process for removing the copper clad on the surface of the insulating substrate;    performing a drilling process for forming a plurality of through holes in the insulating substrate;    disposing a chemical copper layer on the insulating substrate and the sidewall of the through holes for forming a plurality of plated through holes;    forming a wire pattern on the surface of the insulating substrate, wherein the wire pattern includes at least one contact pad;    forming a solder resistant layer on the surface of the insulating substrate and forming at least one opening in the solder resistant layer for exposing the contact pad; and    coating a protective layer on the surface of the contact pad.    
   
   
       2 . The method of  claim 1 , wherein the drilling process is a laser drilling process.  
   
   
       3 . The method of  claim 1 , wherein a surface treatment is performed on the insulating substrate for increasing the adhesiveness of the insulating substrate and the chemical copper layer before the chemical copper layer is disposed.  
   
   
       4 . The method of  claim 3 , wherein the surface treatment is a surface coarsening process.  
   
   
       5 . The method of  claim 1 , wherein the formation of wire pattern further comprises: 
 transferring a photoresist pattern to the surface of the insulating substrate;    forming an electroplating copper layer on the surface of the insulating substrate and the sidewall of the through holes;    performing a photoresist removing process; and    performing an etching process on the insulating substrate for removing the exposed chemical copper layer.    
   
   
       6 . The method of  claim 5 , wherein the photo removing process is a photo stripping process.  
   
   
       7 . The method of  claim 1 , wherein the protective layer is comprised of nickel (Ni).  
   
   
       8 . The method of  claim 1 , wherein the protective layer is comprised of gold (Au).  
   
   
       9 . A method of fabricating a printed circuit board, the method comprising: 
 providing an insulating substrate;    performing a drilling process of forming a plurality of through holes in the insulating substrate;    disposing a chemical copper layer on the insulating substrate and the sidewall of the through holes for forming a plurality of plated through holes; and    forming a wire pattern on the surface of the insulating substrate, wherein the wire pattern includes at least one contact pad.    
   
   
       10 . The method of  claim 9 , wherein the drilling process is a laser drilling process.  
   
   
       11 . The method of  claim 9 , wherein a surface treatment is performed on the insulating substrate for increasing the adhesiveness of the insulating substrate and the chemical copper layer before the chemical copper layer is disposed.  
   
   
       12 . The method of  claim 11 , wherein the surface treatment is a surface coarsening process.  
   
   
       13 . The method of  claim 9 , wherein the formation of wire pattern further comprises: 
 transferring a photoresist pattern to the surface of the insulating substrate;    forming an electroplating copper layer on the surface of the insulating substrate and the sidewall of the through holes;    performing a photo removing process; and    performing an etching process on the insulating substrate for removing the exposed chemical copper layer.    
   
   
       14 . The method of  claim 13 , wherein the photo removing process is a photo stripping process.  
   
   
       15 . The method of  claim 9  further comprising the following steps after the wire pattern on the surface of the insulating substrate is formed: 
 forming a solder resistant layer on the surface of the insulating substrate and forming at least one opening in the solder resistant layer for exposing the contact pad; and    coating a protective layer on the surface of the contact pad.    
   
   
       16 . The method of  claim 15 , wherein the protective layer is comprised of nickel (Ni).  
   
   
       17 . The method of  claim 15 , wherein the protective layer is comprised of gold (Au).  
   
   
       18 . The method of  claim 9 , wherein the insulating substrate is a copper clad laminate (CCL) with copper clad removed.