A sensor is a device that can convert various non-electric quantities (such as physical quantities, chemical quantities, biomasses, etc.) into another physical signal that is convenient for processing and transmission according to certain rules, generally electricity. Sensors typically consist of three components: a sensing element, a conversion element, and a measurement circuit, and sometimes require an additional auxiliary power supply.
The manufacture of semiconductor pressure sensors is based on the principle of the piezoresistive effect of silicon crystals. When a monocrystalline silicon material is subjected to stress, its resistivity changes significantly, a phenomenon known as the piezoresistive effect.
Pressure sensorsUse component materials with piezoresistive effects, such as monocrystalline silicon, diffusion-doped silicon, and polycrystalline silicon. When the crystal is not subjected to directional stress, its conductivity is isotropic;Anisotropy is exhibited only when subjected to directional stress. As the stress causes a change in the energy band and a shift in the energy valley energy, it leads to a change in resistivity, which in turn produces a piezoresistive effect. Monocrystalline silicon effects include n-type and p-type silicon piezoresistive effects. The purpose of selecting diffusion silicon is to select appropriate diffusion conditions according to the piezoresistive characteristics of silicon diffusion lamination at different temperatures when designing and manufacturing pressure sensors, so as to make the pressure sensor have good performance. Polysilicon has a wide range of applications in sensors, and can be used as microstructure and filler materials, sensitive materials.
Depending on the application, pressure sensors can be divided into pressure monitoring, pressure measurement, and pressure control and measurement converted into other physical quantities. Depending on the power supply method, pressure sensors can be divided into piezoresistive and piezoelectric sensors. The former is passively powered and requires an external power source;In the latter, the sensor itself generates an electrical charge and does not require an external power supply. According to the different requirements for pressure measurement accuracy in different fields, pressure sensors can be divided into low-precision and high-precision types.