Overload performance study and fabrication of the capacitive pressure-sensitive chip with linkage film

In order to satisfy the demands of pressure measurement under high overload conditions, the overload characteristics of the capacitive pressure-sensitive chip with linkage film are studied. Through the simulation and analysis for the stress distribution of this sensitive structure and in light of the dimension effect of the tensile strength of monocrystalline silicon, the influence of sizes of the sensitive structure on the overload pressure is expounded. The simulated results illustrate that the maximum overload pressure can exceed 200 times the full-scale (FS) when appropriately adjusting the sizes of the sensitive structure. The proposed chip is fabricated using SOI wafers combined with bonding technology. Our experimental results show that the sample chip has a linear response in the pressure range of 25-100 kPa, and its overload pressure is 4.5 MPa, reaching 45 times the full-scale.