SILICON CAPACITIVE DIFFERENTIAL PRESSURE SENSOR WITH HIGH OVERLOAD PROTECTION

摘要

Pressure transducer (1) comprising: - a first outer silicon electrode (3) arranged in a plane and provided with a first through hole (13) situated on an axis (A-A) substantially perpendicular to said plane; - a second outer silicon electrode (5) arranged substantially parallel to said plane and provided with a second through hole (15) situated on an axis (A-A) substantially perpendicular to said plane; - a central silicon electrode (7) comprising an outer portion (7a) with a first thickness, said outer portion (7a) being bonded on each face to said first and said second outer silicon electrodes (3, 5) respectively by means of a respective insulating layer (9, 11), an inner portion (7c) with a second thickness, said inner portion (7c) being centred on said axis (A-A) facing each of said first and second through holes (13, 15), and an intermediate portion (7b) forming a membrane linking the inner portion (7c) to the outer portion (7a) and having a third thickness less than each of the first and second thicknesses, wherein each of said electrodes (3, 5, 7) is doped to a conductive state, and wherein each of the first and second silicon electrodes (3, 5) are adapt e d to limit the displacement of said inner portion (7c) parallel to said axis (A-A).