Capacitive vacuum pressure sensor

Abstract

The present invention relates to a capacitive pressure sensor for vacuum pressure measurement based on glass and alloy materials, which has strong firmness and corrosion resistance. Sensitivity, high-precision measurement of the pressure value of different pressure sections, using "elastic diaphragms" made of corrosion-resistant elastic alloys with different thicknesses (10-200 microns), these diaphragms are tightly, Symmetrically and stress-free configured in a composite piece made of glass and alloy materials.

Description

technical field [0001] The invention relates to a capacitive pressure sensor for vacuum pressure measurement according to the preamble of claim 1 . Background technique [0002] As we all know, a variable capacitance structure is made by using an elastic thin film structure. When the elastic thin film is subjected to pressure, a change in flexibility occurs, and a known and applicable method is used to make use of the change in its deflection. According to this principle, people use various materials to manufacture capacitive pressure sensing elements with different structures for vacuum pressure measurement. For example, silicon material and glass substrate are selected, and the silicon diaphragm is used as the pressure sensing element of the pressure sensing diaphragm. When used in vacuum, it is impossible to achieve high resolution when measuring lower pressure, and it is affected by environmental factors. Also big. For this reason, various alloys or ceramic materials h...

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Problems solved by technology

For this reason, various alloys or ceramic materials have been selected to manufacture various sensor elements for vacuum pressure measurement, such as the invention and production of the American MKS company, which uses alloy materials to make a sealed shell with a built-in The electrode plate of ceramic material uses an alloy diaphragm as the pressure-sensing diaphragm, and forms a variable capacitance structure. The distance between the electrode plate and the pressure-sensing diaphragm is fixed by a compression ring spring, which is prone to loosening. As a result, the long-term working stability of the sensor element has been affected, and the sensor element for vacuum pressure measurement, which was invented and produced by the German Leybold Company and is entirely constructed of ceramic materials, has avoided the above shortcomings and produced a sensor element Relatively fixed variable capacitance structure

As we all know, although the chemical and physical properties of ceramic materials are stable, they are not strong enough, especially this type of sensor uses a very thin ceramic diaphragm, which is prone to fragmentation under the impact of a certain external force, which affects the sensor. The service life of the components, and the manufacturing process of the above-mentioned sensing elements of this type of structure is complicated, the process requirements are very high, and the manufacturing cost is too high

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