IMAGE SENSOR

An image sensor is provided. The image sensor includes a first substrate; a plurality of photoelectric conversion units positioned in the first substrate; a first connection layer disposed on the first substrate; a plurality of first pixel pads disposed on the first connection layer; a plurality of first peripheral pads disposed on the first substrate; a plurality of second pixel pads respectively positioned on the plurality of first pixel pads; a plurality of second peripheral pads respectively positioned on the plurality of first peripheral pads; a second connection layer disposed on the plurality of second pixel pads and the plurality of second peripheral pads; a device disposed on the second connection layer; and a second substrate disposed on the second connection layer and the device, wherein a pitch of the plurality of first pixel pads is substantially the same as a pitch of the plurality of pixel regions of the first substrate.