Manufacturing method of three-leg catalytic micro gas sensor with temperature modulation

Abstract

The invention provides a micromachining and manufacturing method of a gas sensor with temperature modulation. After a single crystal silicon wafer is subjected to dry oxidation by adopting an IC (Integrated Circuit) process, a silicon nitride dielectric isolation layer and an aluminum oxide dielectric isolation layer are deposited, and a platinum film is deposited by utilizing a sputtering process; patterns are copied on the other side of the single crystal silicon wafer, and a silicon cup is micromachined; a mask is subjected to photoetching and the platinum film is etched by using ion beams to form a gas sensitive unit, a gas compensation unit and a temperature sensitive unit resistor; the mask is subjected to photoetching, and an aluminum oxide layer, a silicon nitride layer, a silicon oxide layer and single crystal silicon are subjected to wet etching in sequence to form a plurality of three-leg chip units; internal leads are welded; aluminum oxide catalytic carrier slurry is coated and sintered; and a catalyst and a desensitizer are coated and subjected to thermal treatment at high temperature to form a gas sensitive chip. The method settles the problems which are present in a catalytic gas sensor owing to manual operation, realizes the integration of a plurality of sensitive units of the sensor, raises the consistency, the reliability and the detection precision of the sensor, and lowers the power consumption.

Description

(1) Technical field [0001] The invention belongs to the field of sensor manufacturing, in particular to a method for manufacturing a three-arm catalytic micro-gas sensor with temperature modulation. (2) Background technology [0002] Catalytic combustion gas sensor is a family of flammable gas sensors with excellent performance and the most widely used type of sensor. Traditional catalytic combustion sensors have the following problems, which affect their performance and applications. (1) Manual winding of the coil, making sensitive heating resistors and compensation resistors, resulting in inconsistent resistance values ​​of the wound coils, resulting in poor matching between the sensitive resistors and compensation resistors, and large differences in the zero output of the sensor. (2) The traditional catalytic combustion sensor can only be operated manually, which is difficult to produce in batches and has poor interchangeability. (3) The power consumption is large, and ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the following problems in traditional catalytic sensors: (1) manual coil winding, making sensitive heating resistors and compensation resistors, resulting in inconsistencies in the resistance values ​​of the winding coils, making the matching of the sensitive resistors and compensation resistors poor, The sensor zero point output has a large difference

Images