Method of manufacturing double-sided printed circuit board

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.