A package structure for packaging at least one of a plurality of integrated circuit devices of a wafer is provided. The package structure includes an extension metal pad, a first conductive bump and an insulator layer. The extension metal pad electrically contacts the at least one of the plurality of integrated circuit devices. The first conductive bump is located on the extension metal pad. The insulator layer is located over the at least one of the plurality of integrated circuit devices and on a sidewall of it.