Flow channel and sealing structure of thermal micro-flow measurement sensor

Abstract

The invention discloses a thermal microflow measurement sensor flow passage and sealing structure which comprises a bottom plate, an element base, a connection plate and a detection element. Both thebottom plate and the connection plate are rectangular plates; a groove for gas circulation and a round hole for mounting the element base are respectively formed on the bottom plate; the axis of the round hole passes through the groove; the element base is a cone frustum; the element base is coaxially welded in the round hole; the detection element for a gas flowing state is mounted on the elementbase; the connection plate is fixedly connected with the bottom plate; the connection plate is respectively provided with a flange for being matched with the groove and a through hole for gas circulation; and the axis of the through hole passes through the flange. According to the invention, by matching between the groove of the bottom plate and the flange of the connection plate, gas turbulenceis avoided and the defect of poor detection stability of an MEMS thermal flow sensor is made up; and by arranging a filling part and welding the bottom plate and the connection plate, reliable sealingbetween the detection element and a gas flow passage is ensured, and the problem of low sealing performance of an MEMS thermal flow sensor structure and a flow passage thereof is solved.

Description

technical field [0001] The invention relates to a flow channel and a sealing structure of a thermal micro-flow measurement sensor, which is especially suitable for installation, sealing and measurement of MEMS thermal flow sensor detection elements, and belongs to the technical field of gas flow sensor structures. Background technique [0002] The detection element of MEMS thermal flow sensor is manufactured based on micro-electromechanical technology. It has the advantages of fast response speed, wide range range, and can measure reverse flow. It is widely used in the field of gas flow measurement. [0003] The detection element of MEMS thermal flow sensor is generally a plate-shaped rectangular element. If the flow of fluid around the detection element is turbulent, it will have a bad influence on the measurement results; when the existing MEMS thermal flow sensor is installed on its detection element , since the detection element needs to be installed on the carrier subst...

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Problems solved by technology

[0003] The detection element of MEMS thermal flow sensor is generally a plate-shaped rectangular element. If the flow of fluid around the detection element is turbulent, it will have a bad influence on the measurement results; when the existing MEMS thermal flow sensor is installed on its detection element , because the detection element needs to be installed on the carrier substrate first, the electrode leads of the detection element are usually led out of the fluid channel by sealing glue, resulting in the destruction of the flow state when the fluid flows through the surface of the detection element, which affects the accuracy of the measurement results

[0004] In addition, the sealing effect of the MEMS thermal flow sensor detection flow channel is poor, and a good seal cannot be achieved, especially in the case of high working pressure, the structure of the MEMS thermal flow sensor and the sealing performance of the detection flow channel cannot be guaranteed

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