Micromachining method of gas-sensitive element with gas-exchanging forcing cold-heat pump

Abstract

The invention relates to the manufacture method of gas-sensitive elements, and provides a micromachining method of a gas-sensitive element with a gas-exchanging forcing cold-heat pump. With the method provided by the invention, a problem of exhausted areas easily appeared around sensitive elements is solved, linearity and performance of the gas-sensitive element is improved, and a calibration period of the gas-sensitive element is prolonged. The method comprises the following steps: deposing to obtain an aluminum film, replicating a cold-heat pump figure, manufacturing an aluminum oxide (Al2O3) film, heat treating, metallizing, and fixing by bonding. With the gas-sensitive element manufactured with the method, gas exchanging is forced between exhaust gas discharged from an element internal detection process and extraneous new gas requiring detection. A gas exchanging circulation is formed in a gas chamber of the gas-sensitive element, and validity and reliability is ensured in gas-sensitive element detection. Meanwhile, failures of the sensitive element due to coking are reduced. The invention assists in the selection and application of detecting monitors.

Description

(1) Technical field [0001] The invention belongs to the field of sensor manufacturing, and in particular relates to a micro-machining manufacturing method of a gas sensor with a forced ventilation cooling and heat pump. (2) Background technology [0002] Catalytic combustion principle gas sensor is a family of flammable gas sensors with excellent performance and the most widely used gas sensor. The traditional catalytic combustion gas sensor has the following structural defects, which affect its use effect. (1) The inner lead is suspended in the air, which leads to the unreliable connection of the sensitive signal contact to the gas sensitive base, and there is a hidden danger of signal transmission. (2) The packaging of traditional flammable gas sensors all adopt open metal shells, and the gas enters the gas chamber by diffusion. If the airflow design around the sensitive element is not good, there will be a depletion area around the sensitive unit, and the volume fractio...

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Problems solved by technology

[0005] The purpose of the present invention is in order to solve the following problems that traditional catalytic combustion type gas sensor exists: (1) gas depletion area can be produced around the sensitive element work of traditional catalytic combustion type gas sensor, measured gas volume fraction is close to zero , resulting in a fatal error in the detection effect of the gas sensor unit; (2) due to the lack of oxygen, it will lead to insufficient combustion of flammable gas, resulting in carbonation failure of the sensor element, resulting in shortened calibration period of the gas sensor element, and greatly reduced gas The linearity of the sensor will degrade the performance of the gas sensor; (3) The internal lead of the traditional catalytic combustion gas sensor is often easily cracked from the solder joint or the inner lead itself is disconnected, resulting in an increase in the failure rate of the gas sensor

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