Abstract: A circuit board assembly comprising an electrically insulating circuit board of synthetic resin having at least one surface laminated with conductive sheet. An electric and/or electronic element, such as resistor or capacitor, of a type which has no lead wires extending outwardly therefrom for external electric connection, but which is constituted by a substantially cubic body having its opposite ends applied with respective films of electro-conductive material which serve as terminal electrodes, is mounted on the circuit board with the electrodes soldered to the respective conductive sheets through immersion of said circuit board, particularly laminated surface thereof, into the pool of molten solder. The circuit board has at least one aperture formed adjacent the area where the element is to be positioned for releasing bubbles evolved in the pool of the solder.