An image sensor comprises a chip, a first redistribution layer (RDL), a second RDL and a third RDL. The chip has a first surface, a second surface opposite to the first surface and a lateral surface extending between the first surface and the second surface. The first RDL is disposed on the first surface of the chip and extends along the first surface of the chip and beyond the lateral surface of the chip. The second RDL is disposed on the second surface of the chip. The third RDL is disposed on the lateral surface of the chip and connects the first RDL to the second RDL.