Thermal airflow sensor and manufacturing method thereof

Abstract

The invention provides a thermal airflow sensor and a manufacturing method thereof. The thermal airflow sensor structurally comprises a substrate, a first medium membrane and a resistor component, wherein a groove is formed in the upper surface of the substrate; the first medium membrane is positioned above the groove and comprises a plurality of first medium membrane units and grooves-shaped structures; the first medium membrane units are connected with the substrate; the groove-shaped structures penetrate through the first medium membrane and are positioned between adjacent first medium units; the first medium membrane and the substrate encircle a thermal-insulating cavity; the resistor component comprises at least one heating unit and at least two thermal sensitive units; each heating unit and each thermal sensitive unit are positioned on different firs medium membrane units; and the thermal sensitive units are positioned on two sides of the heating units. By adopting the technical scheme, the heat of the heating resistors of the thermal airflow sensor provided by the invention is thoroughly isolated from the substrate, so that heat consumption of the heating resistors is reduced, the detection sensitivity of gas flow is improved, and the detection response time is shortened; and the thermal airflow sensor is manufactured by using a single silicon wafer single-side silicon micro mechanical process, and is small in structural size, low in cost and simple in process.

Description

technical field [0001] The invention belongs to the technical field of silicon micromechanical sensors, and relates to a thermal gas flow sensor and a preparation method thereof. Background technique [0002] With the rapid development of MEMS technology, silicon-based thermal gas flow sensors based on MEMS micromachining technology are widely used in aerospace, biochemical detection, medical instruments and other fields due to their advantages of small size and high performance. Especially in recent years, the development of fine chemical industry and medical biological analysis has higher and higher requirements for gas flow measurement and control, and it is difficult for traditional flow measurement devices to meet the requirements. In addition, due to the development of microelectronics manufacturing process, the miniaturization of biomedical and clinical diagnostic instruments and analytical methods has attracted great attention of researchers, which has prompted silic...

AI Technical Summary

Problems solved by technology

[0007] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a thermal gas flow sensor and its preparation method, which are used to solve the problem of high heat dissipation, large size and short response time of the thermal gas flow sensor in the prior art. Slow and so on

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