An image sensor chip includes a semiconductor layer intended to receive illumination on a back face and comprising a matrix of pixels on a front face. An interconnection structure is arranged on the front face and a carrier is attached to the interconnection structure with a first face of the carrier facing the front face. An annular trench, arranged on a perimeter of the image sensor chip, extends from a second face of the carrier through an entire thickness of the carrier and into the interconnection structure. A via opening, arranged within the annual trench, extends from the second face of the carrier through the entire thickness of the carrier to reach a metal portion of the interconnection structure. The via opening an annual trench are lined with an insulating layer. The via opening include a metal conductor making an electrical connection to the metal portion.