To electrically connect a plurality of connecting terminals of an electronic component, e.g., a liquid crystal display device (LCD) to a printed circuit board, a plurality of wiring patterns are first formed on the printed circuit board. These wiring patterns have similar shapes to those of the connecting terminals, and have a signal transmission function. Thereafter, a plurality of dummy patterns are formed outside both outermost wiring patterns on the printed circuit board. These dummy patterns have no signal transmission function. Finally, the connecting terminals of the electronic component are electrically connected via an anisotropically conductive sheet to both the wiring patterns and dummy patterns.