A chip bump structure is formed on a substrate. The substrate includes at least one contact pad and a dielectric layer. The dielectric layer has at least one opening. The at least one opening exposes the at least one contact pad. The chip bump structure includes at least one elastic bump, at least one first metal layer, at least one second metal layer, and at least one solder ball. The at least one elastic bump covers a central portion of the at least one contact pad. The at least one first metal layer covers the at least one elastic bump. The at least one first metal layer has a portion of the at least one contact pad. The portion of the at least one contact pad is not overlaid by the at least one elastic bump. The at least one second metal layer is formed on a portion of the at least one first metal layer. The portion of the at least one first metal layer is located on the top of the at least one elastic bump. The at least one solder ball is formed on the at least one second metal layer. The at least one solder ball is also on the top of the at least one elastic bump.