that is to be disunited itself made up of two wafers 2 and 2 u2032 adhesion is then obtained by vacuum suction for this purpose and as described in detail below the plates 1 and 1 u2032 are constituted by vacuum chambers and by diaphragms e g ceramic diaphragms pierced by orifices or micropores enabling suction to be exerted these plates 1 and 1 u2032 are curved by the action of a series of actuators respectively referenced 3 and 3 u2032 mounted between the rear faces of the plates 1 and 1 u2032 and the facing faces of two rigid slabs 4 and 4 u2032 these slabs are mounted with a single degree of freedom to pivot relative to each other about a pivot axis 6 the slab 4 u2032 being stationary by being mounted on a structure a secondary axis 7 allows means not shown to adjust the angle u03b1 so as to enable the tool to be adapted to assemblies of wafers 2 2 u2032 of different thicknesses by combining pivoting about the axis 6 under the control of the actuator 5 with the deformability of the plates 1 and 1 u2032 and with the individualized action of the actuators 3 and 3 u2032 which are capable of controlling the deformation of said plates this tool makes it possible to control the disuniting force in a manner that is localized precise and reproducible fig3 a and.