For automobile interior, surface-mounted (SMT) LED's have replaced incandescent bulbs and through-hole LED's to backlight the dashboard, radio, displays, and switches for many years. For automobile exterior, high-flux surface- mounted LED's have started replacing the incandescent bulbs in signal lamps, such as center high mounted stop lamp, rear combination lamp and side markers. For these applications, surface-mounted LED's have certain advantages over through- hold LED's and other types of high-flux LED's. Surface- mounted LED's are assembled to the printed circuit board through high-speed automatic pick-and-place standard re-flow soldering processes, so its assembly is more reliable and more cost-efficient than that of through-hole and other types of LED's. Surface-mounted LED's are much smaller than through-hold and other types of LED's, therefore the dashboard or the signal lamps with surface-mounted LED's can be much thinner than with other types of LED's; the liquid crystal displays can be backlit uniformly by coupling the surface-mounted LED's light into a thin light pipe. Surface- mounted LED's can be assembled on the flexible printed circuit substrate, which can be bent like a plastic paper. This provides a solution of stylish 3-dimensional signal lamps, which is more flexible, and more cost-effective than through-hole and other types of LED's can do.