A pad open structure, after an insulation layer is installed at the up of the pad, the insulation layer forms plural pad opens by lithography. The insulation layer is exposed to the surface of the pad by the pad opens. The gold bump forms the upper part of the insulation layer, which forms an electric connection through the pad opens to the pad. By way of this, when the gold bump is formed at the surface of the pad opens and the surrounding insulation layer, reducing the affection produced by a single pad open that hollows the surface of the gold bump such that the gold bump has an extra flat surface.