PROCEDE D'ENCAPSULATION D'UN DISPOSITIF MICROELECTRONIQUE AVEC UN TROU DE LIBERATION DE DIMENSION VARIABLE

A method of encapsulating a microelectronic device (100), comprising the following steps: making a sacrificial portion for covering the device; making a cover (106) for covering the sacrificial portion; the cover (106) comprises two superposed layers (108, 110) of discrete materials with different residual stresses and / or coefficients of thermal expansion; etching a trench (112) through the cover, the pattern of which comprises a curve and / or two non-parallel straight segments; engraving the sacrificial portion through the trench; depositing a sealing material on the trench. During the etching of the sacrificial portion, a portion (116) of the hood defined by the trench deforms under the effect of a mechanical stress generated by the residual stresses and / or thermal expansion of the layers of the hood and increases the dimensions of the trench, and stress is eliminated before the trench is sealed.