A semiconductor structure includes a semiconductor substrate, a pad, a circuit board, a first bump, and a second bump. The pad is disposed on a top surface of the semiconductor substrate. The circuit board includes a contact area corresponding to the pad on the top surface of the semiconductor substrate. The first bump is between the pad on the top surface of the semiconductor substrate and the contact area, wherein the contact area includes a non-metallic surface. The second bump is adjacent the first bump, wherein a first central width of the first bump is larger than a second central width of the second bump.