Micromechanical structure having a deformable membrane and a protection against strong deformations

摘要

The invention relates to a micromechanical structure for measuring or detecting a mechanical quantity or a dynamic quantity, including a deformable membrane (20) and a supporting substrate (10), the membrane (20) including a first portion (20a) and a second portion (20b) surrounded by the first portion (20a), the second portion (20b) having a thickness that is less than the thickness of the first portion (20a), the membrane (20) being suspended above the supporting substrate (10) and thus defining a free space (30), said micromechanical structure comprising in addition a lower abutment (21) for limiting the deformations of the membrane (20), said lower abutment (21) being arranged above the supporting substrate (10) and extending into the free space (30) from said supporting substrate (10) toward the membrane (20), characterized in that the lower abutment (21) comprises islets (101-108) that extend into the free space (30) toward the membrane (20) from a flat surface of the lower abutment (21), the islets (101-108) forming a relief structure in such a manner that, in the case of contact between the islets (101-108) and the fine portion (20b) of the membrane (20), the contact surface between the islets (101-108) and the fine portion (20b) of the membrane (20) is small with respect to the dimensions of the fine portion (20b) of the membrane (20).

主权项

1. A micromechanical structure intended to measure or detect a mechanical magnitude or a dynamic magnitude, including a deformable membrane (20) and a support substrate (10), the membrane (20) including a first part (20a) and a second part (20b) enclosed by the first part (20a), the second part (20b) having a thickness less than the thickness of the first part (20a), the membrane (20) being suspended above the support substrate (10) and thus defining a free space (30), said micromechanical structure also including a lower abutment (21) adapted to limit the deformations of the membrane (20), said lower abutment (21) being arranged above the support substrate (10) and extending in the free space (30) from said support substrate (10) towards the membrane (20), characterized in that the lower abutment (21) includes islets (101-108) which extend into the free space (30) towards the membrane (20) from a flat surface of the lower abutment (21), the islets (101-108) forming a relief structure such that in the event of contact between the islets (101-108) and the second part (20b) of the membrane (20), the contact surface between the islets (101-108) and the second part (20b) of the membrane (20) is small relative to the dimensions of the second part (20b) of the membrane (20).