Gas and pressure composite sensor and preparation method thereof

Abstract

The invention discloses a gas and pressure composite sensor and a preparation method thereof. The sensor comprises a substrate and a bonding wafer, the front face of the substrate is provided with a P-type doped region, a gas sensitive resistor, a temperature measuring resistor and a heating resistor are deposited in a preset region of the front face of the substrate, a strain cavity is prepared in the back face of the substrate, the position of the strain cavity corresponds to a preset area on the front side of the substrate, and a strain film is arranged at the position, right facing the preset area, of the strain cavity; and the back surface of the substrate is bonded with the bonding sheet to form a vacuum strain cavity. The gas and pressure composite sensor has the advantages of high integration level, small size, high measurement precision and the like.

Description

technical field [0001] The invention mainly relates to the technical field of sensor preparation, in particular to a gas and pressure composite sensor and a preparation method thereof. Background technique [0002] With the development of intelligent manufacturing, hydrogen, as an important green new energy, is being used in more and more fields. Especially in recent years, the rapid development of hydrogen energy vehicles has put forward higher requirements for the detection of hydrogen leakage, which needs to be fast and accurate. Low-cost detection of hydrogen leaks. In addition, in transformers, with the continuous use of transformer oil, the hydrogen content in the oil will continue to increase. When it increases to a certain level, fire and explosion hazards may occur, so it is necessary to accurately detect the hydrogen content in the oil in real time. Regardless of hydrogen energy vehicles or transformers, there are high requirements for the accuracy and life of hyd...

AI Technical Summary

Problems solved by technology

H2SCAN company optimizes the control circuit, improves the temperature control accuracy, and increases the chip power to ensure the chip temperature is constant, so as to ensure the measurement accuracy. This method has high cost and high power consumption of the product, so the actual product price is high, and it is difficult in many fields. Promote application

[0004] At present, some domestic imitation H2SCAN hydrogen sensors have been launched, but there is a big gap between the measurement accuracy and reliability of foreign products, mainly in low temperature environments, due to the large heat dissipation of the chip and the difficulty of temperature control, resulting in low measurement accuracy. Improving the temperature control accuracy through circuit compensation and other methods will bring about a significant increase in cost

[0005] In addition, the domestic high-precision pressure sensing chip compensates the pressure-sensitive chip by packaging a temperature-sensitive resistor in the sensor core, measuring the ambient temperature of the core, and combining the characteristic drift of the pressure-sensitive chip at different temperatures. The solution requires an additional circuit chip for calculation and compensation to obtain low temperature drift performance. At the same time, because the temperature measurement chip and the pressure sensitive chip are integrated through the package, there is a physical gap, and there is a temperature difference in an environment with large temperature changes, which will cause the temperature sensor The measurement results are not the actual temperature results of the pressure-sensitive chip, resulting in differences in the pressure measurement results

At the same time, it needs to occupy a large volume through packaging and integration, and it is difficult to achieve miniaturization

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