A method is for making a printed wiring board (PWB) assembly. The method may include forming a first PWB having a plurality of first electrically conductive pads, forming a second PWB including a plurality of electrically conductive traces having exposed ends on an edge surface of the second PWB, and covering the edge surface of the second PWB with an electrically conductive layer. The method may also include selectively removing portions of the electrically conductive layer to define a plurality of second electrically conductive pads electrically connected to corresponding ones of the exposed ends of the electrically conductive traces, and assembling the first and second PWBs together so that the first and second electrically conductive pads are electrically coupled together to define the PWB assembly.