Heat conduction type gas sensor integrated with temperature and humidity measurement function

Abstract

The utility model discloses a thermal conductivity type gas sensor integrated with temperature and humidity measurement functions, which belongs to the technical field of thermal conductivity type gas sensors and comprises a substrate, a support film, a thermal conductivity sensing unit, a temperature sensing unit and a humidity sensing unit. The supporting film is arranged above the substrate and covers the cavity; the overlapped part of the supporting film and the cavity forms a suspended film area; the thermal conductivity sensing unit is arranged on the supporting film and located in the film suspending area. The thermal conductivity sensing unit is used for measuring gas concentration; the temperature sensing unit is arranged on the supporting film and is used for measuring temperature; the humidity sensing unit is arranged on the supporting film and used for measuring humidity. According to the thermal conductivity type gas sensor integrated with the temperature and humidity measurement function, the functions of a thermal conductivity type gas sensor and a temperature and humidity sensor are integrated, so that the test precision of a thermal conductivity sensing unit is improved, the complexity of a test system is reduced, and the thermal conductivity type gas sensor is convenient to use.

Description

Technical Field

[0001] The utility model belongs to the technical field of thermal conductivity gas sensors, and particularly relates to a thermal conductivity gas sensor with integrated temperature and humidity measurement functions. Background Art

[0002] Thermal conductivity gas sensors rely on different thermal conductivities of different measured gases to measure gas concentration. They have the advantages of simple structure, wide measurement range, independence from oxygen, not easily affected by changes in air pressure, and long working life. Therefore, they are widely used in the field of gas composition and concentration detection.

[0003] However, due to the measurement principle of thermal conductivity gas sensors, they are easily affected by changes in ambient temperature and humidity, especially changes in ambient humidity, which greatly interfere with their measurement accuracy. Therefore, when thermal conductivity gas sensors are actually used, they are often required to be used in conjunction with a separate temperature and humidity sensor (which measures temperature and humidity to correct the measurement results of the thermal conductivity gas sensor), which makes them inconvenient to use and makes the entire test system more complicated.

[0004] Therefore, the existing technology needs to be improved and developed. Utility Model Content

[0005] The utility model aims to provide a thermal conductivity gas sensor with integrated temperature and humidity measurement functions, which integrates the functions of the thermal conductivity gas sensor and the temperature and humidity sensor, thereby improving the test accuracy of the thermal conductivity sensing unit and reducing the complexity of the test system for ease of use.

[0006] In a first aspect, the utility model provides a thermal conductivity gas sensor with integrated temperature and humidity measurement functions, comprising:

[0007] A substrate, wherein the substrate is provided with a cavity;

[0008] A supporting film, the supporting film is arranged above the substrate and covers the cavity; the portion where the supporting film overlaps with the cavity constitutes a suspended film area;

[0009] A thermal conductivity sensing unit, the thermal conductivity sensing unit is arranged on the supporting film and located in the suspended film area; the thermal conductivity sensing unit is used to measure the gas concentration;

[0010] A temperature sensing unit, the temperature sensing unit is disposed on the supporting film and is used to measure temperature;

[0011] A humidity sensing unit is disposed on the supporting film and is used to measure humidity.

[0012] The thermal conductivity gas sensor with integrated temperature and humidity measurement function provided by the utility model integrates the functions of the thermal conductivity gas sensor and the temperature and humidity sensor into one, thereby calibrating the thermal conductivity sensing unit by measuring the temperature and humidity of the environment, thereby achieving the effect of greatly improving the measurement accuracy of the thermal conductivity sensing unit.

[0013] Furthermore, the support membrane is a multi-layer composite structure.

[0014] Furthermore, the multilayer composite structure includes alternately stacked silicon dioxide layers and silicon nitride layers.

[0015] Furthermore, the thermal conductivity sensing unit includes a thermal conductivity sensing electrode, and the thermal conductivity sensing electrode is laid directly above the suspended film area.

[0016] Furthermore, the thermal conductivity sensing electrode is in a serpentine shape.

[0017] This helps to ensure that the gas at each position can be heated evenly, thereby ensuring higher measurement accuracy.

[0018] Furthermore, the temperature sensing unit includes a temperature sensing electrode, the humidity sensing unit includes a humidity sensing electrode, and the temperature sensing electrode half surrounds the humidity sensing electrode.

[0019] It is beneficial to reduce the size of the device and to miniaturize the thermal conductivity gas sensor.

[0020] Furthermore, the humidity sensing unit also includes a humidity-sensitive material, and the humidity-sensitive material covers the humidity sensing electrode.

[0021] Furthermore, the humidity sensing electrode is an interdigitated electrode.

[0022] Furthermore, the thermal conductivity sensing electrode, the temperature sensing electrode and the humidity sensing electrode are all made of Pt or Ti metal materials.

[0023] Furthermore, it also includes a protective film, which is simultaneously arranged above the thermal conductivity sensing electrode of the thermal conductivity sensing unit, the temperature sensing electrode of the temperature sensing unit, and the humidity sensing electrode of the humidity sensing unit and is used to press the thermal conductivity sensing electrode, the temperature sensing electrode and the humidity sensing electrode onto the substrate.

[0024] The protective film plays a role in fixing and protecting the thermal conductivity sensing electrode, the temperature sensing electrode and the humidity sensing electrode.

[0025] From the above, it can be seen that the thermal conductivity gas sensor with integrated temperature and humidity measurement function of the utility model integrates the functions of the thermal conductivity gas sensor and the temperature and humidity sensor into one, and controls the temperature and humidity with a single device, thereby reducing the interference of temperature and humidity, improving the measurement accuracy of the thermal conductivity sensing unit and effectively reducing the complexity of the test system for easy use.

[0026] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by implementing the embodiments of the utility model. The purpose and other advantages of the utility model can be achieved and obtained by the structures specifically pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A top view of a thermal conductivity gas sensor with integrated temperature and humidity measurement functions provided by an embodiment of the utility model.

[0028] Figure 2 A side cross-sectional view of a thermal conductivity gas sensor with integrated temperature and humidity measurement functions provided by an embodiment of the utility model.

[0029] Description of labels:

[0030] 100, substrate; 110, cavity; 200, support film; 210, suspended film area; 300, thermal conductivity sensing electrode; 400, temperature sensing electrode; 500, humidity sensing electrode; 510, humidity sensitive material; 600, protective film. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0034] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0036] Reference Figure 1 and attached Figure 2 The utility model provides a thermal conductivity gas sensor with integrated temperature and humidity measurement functions, comprising:

[0037] A substrate 100, wherein the substrate 100 is provided with a cavity 110;

[0038] A support film 200, the support film 200 is disposed above the substrate 100 and covers the cavity 110; the portion where the support film 200 overlaps with the cavity 110 constitutes a suspended film region 210;

[0039] A thermal conductivity sensing unit, which is disposed on the supporting film 200 and located in the suspended film area 210; the thermal conductivity sensing unit is used to measure the gas concentration;

[0040] A temperature sensing unit, which is disposed on the supporting film 200 and is used to measure temperature;

[0041] The humidity sensing unit is disposed on the supporting film 200 and is used to measure humidity.

[0042] In this embodiment, the thermal conductivity sensing unit, the temperature sensing unit and the humidity sensing unit are integrated on the same substrate 100 to manufacture a thermal conductivity gas sensor. In practical applications, the thermal conductivity gas sensor can use the temperature sensing unit and the humidity sensing unit to obtain the temperature and humidity of the current environment, based on which the temperature compensation value and the humidity compensation value can be calculated. Finally, according to the temperature compensation value and the humidity compensation value, the required compensation can be made to the gas concentration value measured by the thermal conductivity sensing unit, thereby compensating for the interference of temperature and humidity and improving the measurement accuracy of the thermal conductivity sensing unit. In addition, since it is no longer necessary to use the temperature sensor and the humidity sensor separately, the complexity of the test system can be effectively reduced, which is more convenient for users to use.

[0043] In some embodiments, the support film 200 is a multi-layer composite structure.

[0044] In some preferred embodiments, the multilayer composite structure includes alternately stacked silicon dioxide layers and silicon nitride layers. For example, the multilayer composite structure is specifically a three-layer composite film structure consisting of a first layer of SiO2, a second layer of SiN and a third layer of SiO2.

[0045] In certain embodiments, referring to Figure 1 and attached Figure 2 The thermal conductivity sensing unit includes a thermal conductivity sensing electrode 300 , and the thermal conductivity sensing electrode 300 is laid directly above the suspended film area 210 .

[0046] In this embodiment, the thermal conductivity sensing electrode 300 generates heat after being energized and forms a heating area in the suspended film area 210 to exchange heat with the external gas, thereby realizing the measurement of gas concentration (the specific principle is common knowledge and will not be repeated here).

[0047] In certain embodiments, referring to Figure 1 The shape of the thermal conductivity sensing electrode 300 is serpentine. The thermal conductivity sensing electrode 300 is laid out in a serpentine shape on the suspended film area 210, which is beneficial to ensure that the gas at each position can be evenly heated, thereby ensuring a higher measurement accuracy.

[0048] In certain embodiments, referring to Figure 1 and attached Figure 2 The temperature sensing unit includes a temperature sensing electrode 400, and the humidity sensing unit includes a humidity sensing electrode 500. The temperature sensing electrode 400 semi-surrounds the humidity sensing electrode 500. The temperature sensing electrode 400 is highly integrated with the humidity sensing electrode 500 in a semi-surrounded form, which is beneficial to reducing the size of the device and facilitating the miniaturization of the thermal conductivity gas sensor.

[0049] In certain embodiments, referring to Figure 2 The humidity sensing unit further includes a humidity sensitive material 510, and the humidity sensitive material 510 covers the humidity sensing electrode 500. The humidity sensitive material is, for example, polyamide resin, cellulose acylate, and metal oxide, but is not limited thereto.

[0050] In certain preferred embodiments, Figure 1 , the humidity sensing electrode 500 is an interdigitated electrode.

[0051] In some embodiments, the thermal conductivity sensing electrode 300 , the temperature sensing electrode 400 , and the humidity sensing electrode 500 are all made of Pt or Ti metal materials.

[0052] In certain embodiments, referring to Figure 2The thermal conductivity gas sensor with integrated temperature and humidity measurement functions also includes a protective film 600, which is simultaneously arranged above the thermal conductivity sensing electrode 300 of the thermal conductivity sensing unit, the temperature sensing electrode 400 of the temperature sensing unit, and the humidity sensing electrode 500 of the humidity sensing unit and is used to press the thermal conductivity sensing electrode 300, the temperature sensing electrode 400 and the humidity sensing electrode 500 onto the substrate.

[0053] In this embodiment, in actual application, the protective film 600 first covers the thermal conductivity sensing electrode 300, the temperature sensing electrode 400 and the humidity sensing electrode 500 at the same time, and then selectively opens windows on the protective film 600. The opened windows are mainly used to expose local positions, for example, to open windows to expose the pads of the thermal conductivity sensing electrode 300, the temperature sensing electrode 400 and the humidity sensing electrode 500 so as to facilitate the connection of the pads with an external power line; for example, to expose windows of humidity-sensitive materials to ensure that the humidity sensing unit can normally measure the ambient humidity, etc., and the remaining protective film 600 plays a role in fixing and protecting the thermal conductivity sensing electrode 300, the temperature sensing electrode 400 and the humidity sensing electrode 500.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0055] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A thermal conductivity gas sensor with integrated temperature and humidity measurement functions, characterized in that: include: A substrate (100), wherein the substrate (100) is provided with a cavity (110); A support film (200), the support film (200) being arranged above the substrate (100) and covering the cavity (110); a portion where the support film (200) overlaps with the cavity (110) constitutes a suspended film region (210); a thermal conductivity sensing unit, the thermal conductivity sensing unit being arranged on the supporting film (200) and located in the suspended film area (210); the thermal conductivity sensing unit being used to measure gas concentration; a temperature sensing unit, the temperature sensing unit being arranged on the supporting film (200) and being used to measure temperature; A humidity sensing unit is arranged on the supporting film (200) and is used to measure humidity.

2. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 1, characterized in that: The supporting film (200) is a multi-layer composite structure.

3. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 2, characterized in that: The multi-layer composite structure includes silicon dioxide layers and silicon nitride layers which are alternately stacked.

4. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 1, characterized in that: The thermal conductivity sensing unit comprises a thermal conductivity sensing electrode (300), and the thermal conductivity sensing electrode (300) is laid directly above the suspended film area (210).

5. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 4, characterized in that: The thermal conductivity sensing electrode (300) is in a serpentine shape.

6. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 4, characterized in that: The temperature sensing unit comprises a temperature sensing electrode (400), the humidity sensing unit comprises a humidity sensing electrode (500), and the temperature sensing electrode (400) semi-surrounds the humidity sensing electrode (500).

7. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 6, characterized in that: The humidity sensing unit further comprises a humidity sensitive material (510), wherein the humidity sensitive material (510) covers the humidity sensing electrode (500).

8. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 6, characterized in that: The humidity sensing electrode (500) is an interdigitated electrode.

9. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 6, characterized in that: The thermal conductivity sensing electrode (300), the temperature sensing electrode (400) and the humidity sensing electrode (500) are all made of Pt or Ti metal materials.

10. The thermal conductivity gas sensor with integrated temperature and humidity measurement functions according to claim 1, characterized in that: The invention also comprises a protective film (600), wherein the protective film (600) is simultaneously arranged above the thermal conductivity sensing electrode (300) of the thermal conductivity sensing unit, the temperature sensing electrode (400) of the temperature sensing unit, and the humidity sensing electrode (500) of the humidity sensing unit, and is used to press the thermal conductivity sensing electrode (300), the temperature sensing electrode (400), and the humidity sensing electrode (500) onto the substrate.

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