An integrated circuit chip is mounted on top of a base wafer, and a protection wafer is mounted on top of the integrated circuit chip. An encapsulation block is formed around the integrated circuit chip and the protection wafer and on a peripheral part of the front face of the base wafer. The encapsulation block includes a first encapsulation ring arranged around the integrated circuit chip and the protection wafer, having an annular beading protruding with respect to the front face of the protection wafer and forming a peripheral groove (24) recessed with respect to this protruding annular beading. A second encapsulation ring of the encapsulation block fills the peripheral groove of the first encapsulation ring.