Novel micro-pressure sensor chip

Abstract

The invention provides a novel micro-pressure sensor chip. The chip comprises a monocrystalline silicon wafer, substrate glass and four force-sensing resistors, wherein the positive side of the monocrystalline silicon wafer is provided with a convex beam, and the four force-sensing resistors are respectively arranged on the convex beam; a groove is formed on the back side of the monocrystalline silicon wafer, and at least two back islands are formed at the bottom of the groove; the convex beam is arranged corresponding to the position of the groove; a frame is formed on the periphery of the groove on the back side of the monocrystalline silicon wafer, and is in bonding encapsulation with the substrate glass. According to the integrated chip design of the islands and the beam, large deformation of the chip under high pressure is avoided, and a good effect of concentrating stress is played, the sensitivity, linearity and overload resistance are improved, and the problems of low sensitivity and poor overload resistance of a conventional flat film structure chip are solved. The novel micro-pressure sensor chip can sense the micro-pressure of between 0 and 200Pa, and has good economical benefit and social benefit.

Description

technical field [0001] The invention belongs to the technical field of pressure sensors, and in particular relates to a novel micro pressure sensor chip. Background technique [0002] Micro pressure sensors are widely used in industrial control, petroleum industry, aerospace, aviation, transportation, metallurgy, machinery manufacturing and other technical fields. However, the existing micro pressure sensors are difficult to meet the market demand in terms of accuracy and quantity. . [0003] The pressure sensor chip uses the piezoresistive effect to convert the external pressure sensed by the sensing diaphragm into changes in strain and stress. The force sensitive resistors are placed at the maximum stress, two force sensitive resistors are placed in the compressive stress area, and the other two are placed in the pressure stress area. The area of ​​tensile stress constitutes a Wheatstone bridge and has the maximum voltage output. For micro pressure sensors, the external ...

AI Technical Summary

Problems solved by technology

For micro pressure sensors, the external pressure sensed is very small. To increase the stress value on the diaphragm, the diaphragm of the sensor must be made very thin, but this will bring two problems: On the one hand, a very thin diaphragm is difficult to process in terms of technology; on the other hand, a relatively thin diaphragm will produce large bending deformation, which will increase the nonlinearity of the sensor sharply and reduce the accuracy of the sensor at the same time.

The flat-membrane chip structure is prone to "balloon effect" in the case of large deflection deformation, which greatly reduces the overload resistance and linearity of the sensor

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