Exemplary embodiments of the present invention illustrate methods to electrically connect multiple layers of a substrate. A first and second layer each has at least one electrical trace on a surface thereof. The substrate includes an interposer structure attached to the second layer and separating the first and second layers on at least a portion of a perimeter of the first and second layers. The method includes a steps for forming a via in the first layer, placing a first electrically conductive substance in the via, placing a second electrically conductive substance on the second layer adjacent said via, and heating an area around said via and said second electrically conductive substance until said first and second electrically conductive substances at least partially melt to form the electrical connection.