A printed circuit board includes a laminated core including at least an internal conductive layer, and a build-up layer on the laminated core. The build-up layer includes a top conductive layer. A plurality of microvias is disposed in the build-up layer to electrically connect the top conductive layer with the internal conductive layer. A power/ground ball pad array is disposed in the top conductive layer. The power/ground ball pad array includes power ball pads and ground ball pads arranged in an array with a fixed ball pad pitch P. The power/ground ball pad array includes a 4-ball pad unit area that is comprised of only one ground ball pad and three power ball pads, or comprised of only one power ball pad and three ground ball pads. The 4-ball pad unit area has a rectangular shape and a dimension of about 2P×2P.