Many aspects of an improved IC package are disclosed herein. The improved IC package exhibits low-impedance and high power and signal integrity. The improved IC package comprises an IC die mounted on a multilayer coreless substrate. The thicknesses of prepreg layers of the coreless substrate are specific chosen to minimize warpage and to provide good mechanical performance. Each of the prepreg layers may have different coefficient of thermal expansion (CTE) and/or thickness to enable better control of the coreless substrate mechanical properties. The improved IC package also includes a vertically mounted die side capacitor and a conductive layer formed on the solder resist layer of the substrate. The conductive layer is formed such that it also encapsulates the vertically mounted capacitor while being electrically coupled to one of the capacitor's electrode.