A package-on-package includes a first package and a second package on the first package. The first package includes a bottom substrate and a top substrate space apart from the bottom substrate such that the bottom substrate and the top substrate define a gap therebetween. A logic die and an IC device are mounted on the bottom substrate in a side-by-side configuration. The logic die has a thickness not less than 125 micrometer. Copper cored solder balls are disposed between around the logic die and the IC device to electrically connect the bottom substrate with the top substrate. A sealing resin is filled into the gap between the bottom substrate and the top substrate and seals the logic die, the IC device, and the copper cored solder balls in the gap.