Double-sided circuit board and method for preparing the same

A method for preparing a circuit board, comprising steps of:

• utilizing a pulse laser to create a circuit pattern that increases a roughness of a non-conductive substrate;
• utilizing the pulse laser to create a through hole penetrating the non-conductive substrate formed with the circuit pattern;
• forming a metallic base layer upon at least one surface and inside the through hole of the non-conductive substrate;
• forming a first metal layer at least upon the metallic base layer;
• removing the metallic base layer and the first metal layer from at least a portion of the non-conductive substrate to create an isolation region surrounding the circuit pattern, wherein the metallic base layer and the first metal layer formed on the circuit pattern are physically separated from a remainder of the metallic base layer and the first metal layer existing upon the at least one surface of the non-conductive substrate outside the circuit pattern;
• and
• forming a second metal layer upon the first metal layer inside the isolation region and the through hole, wherein the second metal layer is restricted from being formed upon the first metal layer outside the isolation region, and wherein the formation of the second metal layer is conducted by electroplating in a manner that electrodes used in the electroplating are connected to make a contact only with one of the metallic base layer and the first metal layer that are inside the isolation region.