Silicon capacitive pressure sensor structure and performance characteristics

Silicon capacitive pressure sensor is based on changes in use of capacitive electrode distance into the pressure changes in the capacitance produced by the MEMS sensor technology.

Major problem

Capacitive detection principle is used because of its very distance change, and this change in itself is extremely non-linear space, in order to improve the linearity, the development of more complex core structure, such as contact, variable area and variable pole pitch in series structure. Another problem is the displacement sensor capacitor to solve the weak signal detection.

Silicon capacitive pressure sensor performance characteristics:

I, for mass production, low cost

Silicon capacitive pressure sensors using MEMS fabrication, the chip size of 3mm ¡Á 3mm, a 4-inch silicon wafer can produce hundreds of components. Product of the process is good, consistent performance, suitable for mass production, low-cost operation. The preparation process is compatible with IC process technology and equipment do not like silicon resonant sensor technology as expensive and complex equipment, but also do not like the metal diaphragm capacitance sensor as a single piece production, to ensure that the silicon capacitive sensor with high performance and low cost.

Second, the stability

Silicon capacitive pressure sensor is a structure-based sensors, pressure sensors for detecting principle, its stability is better than physical sensors, from the design point of view to ensure the stability of such sensors; structure of solid-state technology with full hard closure process, silicon - glass - metal conductor electrostatic pressure pipe seal, reducing the use of plastic closures, etc., causing the stress, delay and delay variation; capacitance insensitive to temperature, the temperature an additional error is small, as the silicon piezoresistive devices that do not need complex temperature compensation. Stability is the silicon capacitance sensor by the user a good impression of the main reasons.

Third, the indicators advanced

Capacitance sensor itself has a low power, high impedance, electrostatic attraction of small, movable mass is small, the characteristics of the small heat effects, and non-contact measurement. Silicon capacitive sensor integrated performance indicators such as non-linear, overload, static pressure, reliability, better performance than silicon piezoresistive sensors, ceramic sensor, metal diaphragm condenser transducer. It silicon resonant sensor with a considerable, especially in pursuit of the nonlinear index users, often better than silicon capacitive sensors for non-linear rate of 0.05% FS is greater than 60% of finished