A gradient microporous filter gas sensor and its preparation method

Abstract

The invention belongs to the field of gas sensor manufacturing, and specifically discloses a gradient microporous filter gas sensor and a preparation method thereof. The sensor includes an upper sampling chamber, a sensing array, a circuit board, and a lower sampling chamber arranged in sequence from top to bottom, wherein: the upper sampling chamber is used to pass in test gas and send it into the sensing array; the sensing array The array includes a preset number of sensing units for gradient microporous filtration of the test gas; the circuit board is connected to the sensing array for receiving the identification signal of the sensing array; the sampling lower chamber is used for introducing zero gas, Therefore, it is ensured that the air pressure of the lower sampling chamber is lower than the air pressure of the upper sampling chamber, and the passing speed of the test gas is increased. The invention can form a pressure difference in the upper and lower chambers, effectively increase the passing speed of the test gas, thereby shortening the response recovery time, and at the same time can realize gradient microporous filtration of the test gas and realize multi-component gas detection in complex atmospheres.

Description

technical field [0001] The invention belongs to the field of gas sensor manufacturing, and more specifically relates to a gradient microporous filter gas sensor and a preparation method thereof. Background technique [0002] Gas multi-component detection is a detection method that distinguishes the types and corresponding concentrations of each component gas, which is very important for air quality detection and industrial gas emission component detection. Its detection types and methods are very rich. Traditional methods generally use technologies such as gas chromatography, ion mobility spectrometry, and continuous spectral absorption. The signal is expanded on the spectrum and absorption spectrum, so as to distinguish the type and concentration of each component gas in the multi-component. However, the use of gas spectroscopy signals to separate various gases has certain limitations, especially due to the heavy detection equipment that cannot be miniaturized and low powe...

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Problems solved by technology

[0004] At present, a microporous film can be deposited on the gas-sensitive film by means of screen printing, in-situ growth, etc., but this contact-type laminated structure will have the following problems: 1. The response recovery speed of the sensor under the filter film is extremely slow 2. The film formation of the microporous filtration membrane requires the gas-sensitive membrane as the seed / substrate, and it is difficult to prepare a continuous filtration membrane; 3. The preparation methods such as in-situ growth are difficult to be compatible with the semiconductor batch process; 4. Metal oxide gas The sensitive membrane needs to work at a certain working temperature (room temperature to 400°C), and the temperature shock can easily lead to damage to the structure of the microporous filtration membrane

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