A fabrication method for PCBs. The method includes providing a substrate having a layout area and a periphery area around the layout area on a surface, forming a patterned wiring layer, having a bus line in the periphery area, a plurality of pads in the layout area, a plurality of bridge lines providing electrical connection between the pads, and a plating line electrically connecting the bus line and pads, overlying the substrate, forming a patterned solder mask over the substrate and wiring layer, the patterned solder mask having a plurality of first openings respectively exposing the pads and plating a metal layer respectively overlying the pads, forming a plurality of second openings respectively exposing the bridge lines between the pads, and removing the exposed bridge lines.